diff --git a/g10/getkey.c b/g10/getkey.c
index 20b717b50..41e39a0d9 100644
--- a/g10/getkey.c
+++ b/g10/getkey.c
@@ -1,4585 +1,4587 @@
 /* getkey.c -  Get a key from the database
  * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
  *               2007, 2008, 2010  Free Software Foundation, Inc.
  * Copyright (C) 2015, 2016 g10 Code GmbH
  *
  * This file is part of GnuPG.
  *
  * GnuPG is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 3 of the License, or
  * (at your option) any later version.
  *
  * GnuPG is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see <https://www.gnu.org/licenses/>.
  */
 
 #include <config.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
 
 #include "gpg.h"
 #include "../common/util.h"
 #include "packet.h"
 #include "../common/iobuf.h"
 #include "keydb.h"
 #include "options.h"
 #include "main.h"
 #include "trustdb.h"
 #include "../common/i18n.h"
 #include "keyserver-internal.h"
 #include "call-agent.h"
 #include "../common/host2net.h"
 #include "../common/mbox-util.h"
 #include "../common/status.h"
 
 #define MAX_PK_CACHE_ENTRIES   PK_UID_CACHE_SIZE
 #define MAX_UID_CACHE_ENTRIES  PK_UID_CACHE_SIZE
 
 #if MAX_PK_CACHE_ENTRIES < 2
 #error We need the cache for key creation
 #endif
 
 /* Flags values returned by the lookup code.  Note that the values are
  * directly used by the KEY_CONSIDERED status line.  */
 #define LOOKUP_NOT_SELECTED        (1<<0)
 #define LOOKUP_ALL_SUBKEYS_EXPIRED (1<<1)  /* or revoked */
 
 
 /* A context object used by the lookup functions.  */
 struct getkey_ctx_s
 {
   /* Part of the search criteria: whether the search is an exact
      search or not.  A search that is exact requires that a key or
      subkey meet all of the specified criteria.  A search that is not
      exact allows selecting a different key or subkey from the
      keyblock that matched the critera.  Further, an exact search
      returns the key or subkey that matched whereas a non-exact search
      typically returns the primary key.  See finish_lookup for
      details.  */
   int exact;
 
   /* Part of the search criteria: Whether the caller only wants keys
      with an available secret key.  This is used by getkey_next to get
      the next result with the same initial criteria.  */
   int want_secret;
 
   /* Part of the search criteria: The type of the requested key.  A
      mask of PUBKEY_USAGE_SIG, PUBKEY_USAGE_ENC and PUBKEY_USAGE_CERT.
      If non-zero, then for a key to match, it must implement one of
      the required uses.  */
   int req_usage;
 
   /* The database handle.  */
   KEYDB_HANDLE kr_handle;
 
   /* Whether we should call xfree() on the context when the context is
      released using getkey_end()).  */
   int not_allocated;
 
   /* This variable is used as backing store for strings which have
      their address used in ITEMS.  */
   strlist_t extra_list;
 
   /* Hack to return the mechanism (AKL_foo) used to find the key.  */
   int found_via_akl;
 
   /* Part of the search criteria: The low-level search specification
      as passed to keydb_search.  */
   int nitems;
   /* This must be the last element in the structure.  When we allocate
      the structure, we allocate it so that ITEMS can hold NITEMS.  */
   KEYDB_SEARCH_DESC items[1];
 };
 
 #if 0
 static struct
 {
   int any;
   int okay_count;
   int nokey_count;
   int error_count;
 } lkup_stats[21];
 #endif
 
 typedef struct keyid_list
 {
   struct keyid_list *next;
   char fpr[MAX_FINGERPRINT_LEN];
   u32 keyid[2];
 } *keyid_list_t;
 
 
 #if MAX_PK_CACHE_ENTRIES
 typedef struct pk_cache_entry
 {
   struct pk_cache_entry *next;
   u32 keyid[2];
   PKT_public_key *pk;
 } *pk_cache_entry_t;
 static pk_cache_entry_t pk_cache;
 static int pk_cache_entries;	/* Number of entries in pk cache.  */
 static int pk_cache_disabled;
 #endif
 
 #if MAX_UID_CACHE_ENTRIES < 5
 #error we really need the userid cache
 #endif
 typedef struct user_id_db
 {
   struct user_id_db *next;
   keyid_list_t keyids;
   int len;
   char name[1];
 } *user_id_db_t;
 static user_id_db_t user_id_db;
 static int uid_cache_entries;	/* Number of entries in uid cache. */
 
 static void merge_selfsigs (ctrl_t ctrl, kbnode_t keyblock);
 static int lookup (ctrl_t ctrl, getkey_ctx_t ctx, int want_secret,
 		   kbnode_t *ret_keyblock, kbnode_t *ret_found_key);
 static kbnode_t finish_lookup (kbnode_t keyblock,
                                unsigned int req_usage, int want_exact,
                                int want_secret, unsigned int *r_flags);
 static void print_status_key_considered (kbnode_t keyblock, unsigned int flags);
 
 
 #if 0
 static void
 print_stats ()
 {
   int i;
   for (i = 0; i < DIM (lkup_stats); i++)
     {
       if (lkup_stats[i].any)
 	es_fprintf (es_stderr,
 		 "lookup stats: mode=%-2d  ok=%-6d  nokey=%-6d  err=%-6d\n",
 		 i,
 		 lkup_stats[i].okay_count,
 		 lkup_stats[i].nokey_count, lkup_stats[i].error_count);
     }
 }
 #endif
 
 
 /* Cache a copy of a public key in the public key cache.  PK is not
  * cached if caching is disabled (via getkey_disable_caches), if
  * PK->FLAGS.DONT_CACHE is set, we don't know how to derive a key id
  * from the public key (e.g., unsupported algorithm), or a key with
  * the key id is already in the cache.
  *
  * The public key packet is copied into the cache using
  * copy_public_key.  Thus, any secret parts are not copied, for
  * instance.
  *
  * This cache is filled by get_pubkey and is read by get_pubkey and
  * get_pubkey_fast.  */
 void
 cache_public_key (PKT_public_key * pk)
 {
 #if MAX_PK_CACHE_ENTRIES
   pk_cache_entry_t ce, ce2;
   u32 keyid[2];
 
   if (pk_cache_disabled)
     return;
 
   if (pk->flags.dont_cache)
     return;
 
   if (is_ELGAMAL (pk->pubkey_algo)
       || pk->pubkey_algo == PUBKEY_ALGO_DSA
       || pk->pubkey_algo == PUBKEY_ALGO_ECDSA
       || pk->pubkey_algo == PUBKEY_ALGO_EDDSA
       || pk->pubkey_algo == PUBKEY_ALGO_ECDH
       || is_RSA (pk->pubkey_algo))
     {
       keyid_from_pk (pk, keyid);
     }
   else
     return; /* Don't know how to get the keyid.  */
 
   for (ce = pk_cache; ce; ce = ce->next)
     if (ce->keyid[0] == keyid[0] && ce->keyid[1] == keyid[1])
       {
 	if (DBG_CACHE)
 	  log_debug ("cache_public_key: already in cache\n");
 	return;
       }
 
   if (pk_cache_entries >= MAX_PK_CACHE_ENTRIES)
     {
       int n;
 
       /* Remove the last 50% of the entries.  */
       for (ce = pk_cache, n = 0; ce && n < pk_cache_entries/2; n++)
         ce = ce->next;
       if (ce && ce != pk_cache && ce->next)
         {
           ce2 = ce->next;
           ce->next = NULL;
           ce = ce2;
           for (; ce; ce = ce2)
             {
               ce2 = ce->next;
               free_public_key (ce->pk);
               xfree (ce);
               pk_cache_entries--;
             }
         }
       log_assert (pk_cache_entries < MAX_PK_CACHE_ENTRIES);
     }
   pk_cache_entries++;
   ce = xmalloc (sizeof *ce);
   ce->next = pk_cache;
   pk_cache = ce;
   ce->pk = copy_public_key (NULL, pk);
   ce->keyid[0] = keyid[0];
   ce->keyid[1] = keyid[1];
 #endif
 }
 
 
 /* Return a const utf-8 string with the text "[User ID not found]".
    This function is required so that we don't need to switch gettext's
    encoding temporary.  */
 static const char *
 user_id_not_found_utf8 (void)
 {
   static char *text;
 
   if (!text)
     text = native_to_utf8 (_("[User ID not found]"));
   return text;
 }
 
 
 
 /* Return the user ID from the given keyblock.
  * We use the primary uid flag which has been set by the merge_selfsigs
  * function.  The returned value is only valid as long as the given
  * keyblock is not changed.  */
 static const char *
 get_primary_uid (KBNODE keyblock, size_t * uidlen)
 {
   KBNODE k;
   const char *s;
 
   for (k = keyblock; k; k = k->next)
     {
       if (k->pkt->pkttype == PKT_USER_ID
 	  && !k->pkt->pkt.user_id->attrib_data
 	  && k->pkt->pkt.user_id->flags.primary)
 	{
 	  *uidlen = k->pkt->pkt.user_id->len;
 	  return k->pkt->pkt.user_id->name;
 	}
     }
   s = user_id_not_found_utf8 ();
   *uidlen = strlen (s);
   return s;
 }
 
 
 static void
 release_keyid_list (keyid_list_t k)
 {
   while (k)
     {
       keyid_list_t k2 = k->next;
       xfree (k);
       k = k2;
     }
 }
 
 /****************
  * Store the association of keyid and userid
  * Feed only public keys to this function.
  */
 static void
 cache_user_id (KBNODE keyblock)
 {
   user_id_db_t r;
   const char *uid;
   size_t uidlen;
   keyid_list_t keyids = NULL;
   KBNODE k;
 
   for (k = keyblock; k; k = k->next)
     {
       if (k->pkt->pkttype == PKT_PUBLIC_KEY
 	  || k->pkt->pkttype == PKT_PUBLIC_SUBKEY)
 	{
 	  keyid_list_t a = xmalloc_clear (sizeof *a);
 	  /* Hmmm: For a long list of keyids it might be an advantage
 	   * to append the keys.  */
           fingerprint_from_pk (k->pkt->pkt.public_key, a->fpr, NULL);
 	  keyid_from_pk (k->pkt->pkt.public_key, a->keyid);
 	  /* First check for duplicates.  */
 	  for (r = user_id_db; r; r = r->next)
 	    {
 	      keyid_list_t b;
 
 	      for (b = r->keyids; b; b = b->next)
 		{
 		  if (!memcmp (b->fpr, a->fpr, MAX_FINGERPRINT_LEN))
 		    {
 		      if (DBG_CACHE)
 			log_debug ("cache_user_id: already in cache\n");
 		      release_keyid_list (keyids);
 		      xfree (a);
 		      return;
 		    }
 		}
 	    }
 	  /* Now put it into the cache.  */
 	  a->next = keyids;
 	  keyids = a;
 	}
     }
   if (!keyids)
     BUG (); /* No key no fun.  */
 
 
   uid = get_primary_uid (keyblock, &uidlen);
 
   if (uid_cache_entries >= MAX_UID_CACHE_ENTRIES)
     {
       /* fixme: use another algorithm to free some cache slots */
       r = user_id_db;
       user_id_db = r->next;
       release_keyid_list (r->keyids);
       xfree (r);
       uid_cache_entries--;
     }
   r = xmalloc (sizeof *r + uidlen - 1);
   r->keyids = keyids;
   r->len = uidlen;
   memcpy (r->name, uid, r->len);
   r->next = user_id_db;
   user_id_db = r;
   uid_cache_entries++;
 }
 
 
 /* Disable and drop the public key cache (which is filled by
    cache_public_key and get_pubkey).  Note: there is currently no way
    to re-enable this cache.  */
 void
 getkey_disable_caches ()
 {
 #if MAX_PK_CACHE_ENTRIES
   {
     pk_cache_entry_t ce, ce2;
 
     for (ce = pk_cache; ce; ce = ce2)
       {
 	ce2 = ce->next;
 	free_public_key (ce->pk);
 	xfree (ce);
       }
     pk_cache_disabled = 1;
     pk_cache_entries = 0;
     pk_cache = NULL;
   }
 #endif
   /* fixme: disable user id cache ? */
 }
 
 
 /* Free a list of pubkey_t objects.  */
 void
 pubkeys_free (pubkey_t keys)
 {
   while (keys)
     {
       pubkey_t next = keys->next;
       xfree (keys->pk);
       release_kbnode (keys->keyblock);
       xfree (keys);
       keys = next;
     }
 }
 
 
 static void
 pk_from_block (PKT_public_key *pk, kbnode_t keyblock, kbnode_t found_key)
 {
   kbnode_t a = found_key ? found_key : keyblock;
 
   log_assert (a->pkt->pkttype == PKT_PUBLIC_KEY
               || a->pkt->pkttype == PKT_PUBLIC_SUBKEY);
 
   copy_public_key (pk, a->pkt->pkt.public_key);
 }
 
 
 /* Specialized version of get_pubkey which retrieves the key based on
  * information in SIG.  In contrast to get_pubkey PK is required.  IF
  * FORCED_PK is not NULL, this public key is used and copied to PK. */
 gpg_error_t
 get_pubkey_for_sig (ctrl_t ctrl, PKT_public_key *pk, PKT_signature *sig,
                     PKT_public_key *forced_pk)
 {
   const byte *fpr;
   size_t fprlen;
 
   if (forced_pk)
     {
       copy_public_key (pk, forced_pk);
       return 0;
     }
 
   /* First try the new ISSUER_FPR info.  */
   fpr = issuer_fpr_raw (sig, &fprlen);
   if (fpr && !get_pubkey_byfprint (ctrl, pk, NULL, fpr, fprlen))
     return 0;
 
   /* Fallback to use the ISSUER_KEYID.  */
   return get_pubkey (ctrl, pk, sig->keyid);
 }
 
 
 /* Return the public key with the key id KEYID and store it at PK.
  * The resources in *PK should be released using
  * release_public_key_parts().  This function also stores a copy of
  * the public key in the user id cache (see cache_public_key).
  *
  * If PK is NULL, this function just stores the public key in the
  * cache and returns the usual return code.
  *
  * PK->REQ_USAGE (which is a mask of PUBKEY_USAGE_SIG,
  * PUBKEY_USAGE_ENC and PUBKEY_USAGE_CERT) is passed through to the
  * lookup function.  If this is non-zero, only keys with the specified
  * usage will be returned.  As such, it is essential that
  * PK->REQ_USAGE be correctly initialized!
  *
  * Returns 0 on success, GPG_ERR_NO_PUBKEY if there is no public key
  * with the specified key id, or another error code if an error
  * occurs.
  *
  * If the data was not read from the cache, then the self-signed data
  * has definitely been merged into the public key using
  * merge_selfsigs.  */
 int
 get_pubkey (ctrl_t ctrl, PKT_public_key * pk, u32 * keyid)
 {
   int internal = 0;
   int rc = 0;
 
 #if MAX_PK_CACHE_ENTRIES
   if (pk)
     {
       /* Try to get it from the cache.  We don't do this when pk is
          NULL as it does not guarantee that the user IDs are
          cached. */
       pk_cache_entry_t ce;
       for (ce = pk_cache; ce; ce = ce->next)
 	{
 	  if (ce->keyid[0] == keyid[0] && ce->keyid[1] == keyid[1])
 	    /* XXX: We don't check PK->REQ_USAGE here, but if we don't
 	       read from the cache, we do check it!  */
 	    {
 	      copy_public_key (pk, ce->pk);
 	      return 0;
 	    }
 	}
     }
 #endif
   /* More init stuff.  */
   if (!pk)
     {
       internal++;
       pk = xtrycalloc (1, sizeof *pk);
       if (!pk)
         {
           rc = gpg_error_from_syserror ();
           goto leave;
         }
     }
 
 
   /* Do a lookup.  */
   {
     struct getkey_ctx_s ctx;
     kbnode_t kb = NULL;
     kbnode_t found_key = NULL;
 
     memset (&ctx, 0, sizeof ctx);
     ctx.exact = 1; /* Use the key ID exactly as given.  */
     ctx.not_allocated = 1;
 
     if (ctrl && ctrl->cached_getkey_kdb)
       {
         ctx.kr_handle = ctrl->cached_getkey_kdb;
         ctrl->cached_getkey_kdb = NULL;
         keydb_search_reset (ctx.kr_handle);
       }
     else
       {
         ctx.kr_handle = keydb_new ();
         if (!ctx.kr_handle)
           {
             rc = gpg_error_from_syserror ();
             goto leave;
           }
       }
     ctx.nitems = 1;
     ctx.items[0].mode = KEYDB_SEARCH_MODE_LONG_KID;
     ctx.items[0].u.kid[0] = keyid[0];
     ctx.items[0].u.kid[1] = keyid[1];
     ctx.req_usage = pk->req_usage;
     rc = lookup (ctrl, &ctx, 0, &kb, &found_key);
     if (!rc)
       {
 	pk_from_block (pk, kb, found_key);
       }
     getkey_end (ctrl, &ctx);
     release_kbnode (kb);
   }
   if (!rc)
     goto leave;
 
   rc = GPG_ERR_NO_PUBKEY;
 
 leave:
   if (!rc)
     cache_public_key (pk);
   if (internal)
     free_public_key (pk);
   return rc;
 }
 
 
 /* Same as get_pubkey but if the key was not found the function tries
  * to import it from LDAP.  FIXME: We should not need this but swicth
  * to a fingerprint lookup.  */
 gpg_error_t
 get_pubkey_with_ldap_fallback (ctrl_t ctrl, PKT_public_key *pk, u32 *keyid)
 {
   gpg_error_t err;
 
   err = get_pubkey (ctrl, pk, keyid);
   if (!err)
     return 0;
 
   if (gpg_err_code (err) != GPG_ERR_NO_PUBKEY)
     return err;
 
   /* Note that this code does not handle the case for two readers
    * having both openpgp encryption keys.  Only one will be tried.  */
   if (opt.debug)
     log_debug ("using LDAP to find a public key\n");
   err = keyserver_import_keyid (ctrl, keyid,
                                 opt.keyserver, KEYSERVER_IMPORT_FLAG_LDAP);
   if (gpg_err_code (err) == GPG_ERR_NO_DATA
       || gpg_err_code (err) == GPG_ERR_NO_KEYSERVER)
     {
       /* Dirmngr returns NO DATA is the selected keyserver
        * does not have the requested key.  It returns NO
        * KEYSERVER if no LDAP keyservers are configured.  */
       err = gpg_error (GPG_ERR_NO_PUBKEY);
     }
   if (err)
     return err;
 
   return get_pubkey (ctrl, pk, keyid);
 }
 
 
 /* Similar to get_pubkey, but it does not take PK->REQ_USAGE into
  * account nor does it merge in the self-signed data.  This function
  * also only considers primary keys.  It is intended to be used as a
  * quick check of the key to avoid recursion.  It should only be used
  * in very certain cases.  Like get_pubkey and unlike any of the other
  * lookup functions, this function also consults the user id cache
  * (see cache_public_key).
  *
  * Return the public key in *PK.  The resources in *PK should be
  * released using release_public_key_parts().  */
 int
 get_pubkey_fast (PKT_public_key * pk, u32 * keyid)
 {
   int rc = 0;
   KEYDB_HANDLE hd;
   KBNODE keyblock;
   u32 pkid[2];
 
   log_assert (pk);
 #if MAX_PK_CACHE_ENTRIES
   {
     /* Try to get it from the cache */
     pk_cache_entry_t ce;
 
     for (ce = pk_cache; ce; ce = ce->next)
       {
 	if (ce->keyid[0] == keyid[0] && ce->keyid[1] == keyid[1]
 	    /* Only consider primary keys.  */
 	    && ce->pk->keyid[0] == ce->pk->main_keyid[0]
 	    && ce->pk->keyid[1] == ce->pk->main_keyid[1])
 	  {
 	    if (pk)
 	      copy_public_key (pk, ce->pk);
 	    return 0;
 	  }
       }
   }
 #endif
 
   hd = keydb_new ();
   if (!hd)
     return gpg_error_from_syserror ();
   rc = keydb_search_kid (hd, keyid);
   if (gpg_err_code (rc) == GPG_ERR_NOT_FOUND)
     {
       keydb_release (hd);
       return GPG_ERR_NO_PUBKEY;
     }
   rc = keydb_get_keyblock (hd, &keyblock);
   keydb_release (hd);
   if (rc)
     {
       log_error ("keydb_get_keyblock failed: %s\n", gpg_strerror (rc));
       return GPG_ERR_NO_PUBKEY;
     }
 
   log_assert (keyblock && keyblock->pkt
               && keyblock->pkt->pkttype == PKT_PUBLIC_KEY);
 
   /* We return the primary key.  If KEYID matched a subkey, then we
      return an error.  */
   keyid_from_pk (keyblock->pkt->pkt.public_key, pkid);
   if (keyid[0] == pkid[0] && keyid[1] == pkid[1])
     copy_public_key (pk, keyblock->pkt->pkt.public_key);
   else
     rc = GPG_ERR_NO_PUBKEY;
 
   release_kbnode (keyblock);
 
   /* Not caching key here since it won't have all of the fields
      properly set. */
 
   return rc;
 }
 
 
 /* Return the entire keyblock used to create SIG.  This is a
  * specialized version of get_pubkeyblock.
  *
  * FIXME: This is a hack because get_pubkey_for_sig was already called
  * and it could have used a cache to hold the key.  */
 kbnode_t
 get_pubkeyblock_for_sig (ctrl_t ctrl, PKT_signature *sig)
 {
   const byte *fpr;
   size_t fprlen;
   kbnode_t keyblock;
 
   /* First try the new ISSUER_FPR info.  */
   fpr = issuer_fpr_raw (sig, &fprlen);
   if (fpr && !get_pubkey_byfprint (ctrl, NULL, &keyblock, fpr, fprlen))
     return keyblock;
 
   /* Fallback to use the ISSUER_KEYID.  */
   return get_pubkeyblock (ctrl, sig->keyid);
 }
 
 
 /* Return the key block for the key with key id KEYID or NULL, if an
  * error occurs.  Use release_kbnode() to release the key block.
  *
  * The self-signed data has already been merged into the public key
  * using merge_selfsigs.  */
 kbnode_t
 get_pubkeyblock (ctrl_t ctrl, u32 * keyid)
 {
   struct getkey_ctx_s ctx;
   int rc = 0;
   KBNODE keyblock = NULL;
 
   memset (&ctx, 0, sizeof ctx);
   /* No need to set exact here because we want the entire block.  */
   ctx.not_allocated = 1;
   ctx.kr_handle = keydb_new ();
   if (!ctx.kr_handle)
     return NULL;
   ctx.nitems = 1;
   ctx.items[0].mode = KEYDB_SEARCH_MODE_LONG_KID;
   ctx.items[0].u.kid[0] = keyid[0];
   ctx.items[0].u.kid[1] = keyid[1];
   rc = lookup (ctrl, &ctx, 0, &keyblock, NULL);
   getkey_end (ctrl, &ctx);
 
   return rc ? NULL : keyblock;
 }
 
 
 /* Return the public key with the key id KEYID iff the secret key is
  * available and store it at PK.  The resources should be released
  * using release_public_key_parts().
  *
  * Unlike other lookup functions, PK may not be NULL.  PK->REQ_USAGE
  * is passed through to the lookup function and is a mask of
  * PUBKEY_USAGE_SIG, PUBKEY_USAGE_ENC and PUBKEY_USAGE_CERT.  Thus, it
  * must be valid!  If this is non-zero, only keys with the specified
  * usage will be returned.
  *
  * Returns 0 on success.  If a public key with the specified key id is
  * not found or a secret key is not available for that public key, an
  * error code is returned.  Note: this function ignores legacy keys.
  * An error code is also return if an error occurs.
  *
  * The self-signed data has already been merged into the public key
  * using merge_selfsigs.  */
 gpg_error_t
 get_seckey (ctrl_t ctrl, PKT_public_key *pk, u32 *keyid)
 {
   gpg_error_t err;
   struct getkey_ctx_s ctx;
   kbnode_t keyblock = NULL;
   kbnode_t found_key = NULL;
 
   memset (&ctx, 0, sizeof ctx);
   ctx.exact = 1; /* Use the key ID exactly as given.  */
   ctx.not_allocated = 1;
   ctx.kr_handle = keydb_new ();
   if (!ctx.kr_handle)
     return gpg_error_from_syserror ();
   ctx.nitems = 1;
   ctx.items[0].mode = KEYDB_SEARCH_MODE_LONG_KID;
   ctx.items[0].u.kid[0] = keyid[0];
   ctx.items[0].u.kid[1] = keyid[1];
   ctx.req_usage = pk->req_usage;
   err = lookup (ctrl, &ctx, 1, &keyblock, &found_key);
   if (!err)
     {
       pk_from_block (pk, keyblock, found_key);
     }
   getkey_end (ctrl, &ctx);
   release_kbnode (keyblock);
 
   if (!err)
     {
       if (!agent_probe_secret_key (/*ctrl*/NULL, pk))
         {
           release_public_key_parts (pk);
           err = gpg_error (GPG_ERR_NO_SECKEY);
         }
     }
 
   return err;
 }
 
 
 /* Skip unusable keys.  A key is unusable if it is revoked, expired or
    disabled or if the selected user id is revoked or expired.  */
 static int
 skip_unusable (void *opaque, u32 * keyid, int uid_no)
 {
   ctrl_t ctrl = opaque;
   int unusable = 0;
   KBNODE keyblock;
   PKT_public_key *pk;
 
   keyblock = get_pubkeyblock (ctrl, keyid);
   if (!keyblock)
     {
       log_error ("error checking usability status of %s\n", keystr (keyid));
       goto leave;
     }
 
   pk = keyblock->pkt->pkt.public_key;
 
   /* Is the key revoked or expired?  */
   if (pk->flags.revoked || pk->has_expired)
     unusable = 1;
 
   /* Is the user ID in question revoked or expired? */
   if (!unusable && uid_no)
     {
       KBNODE node;
       int uids_seen = 0;
 
       for (node = keyblock; node; node = node->next)
 	{
 	  if (node->pkt->pkttype == PKT_USER_ID)
 	    {
 	      PKT_user_id *user_id = node->pkt->pkt.user_id;
 
 	      uids_seen ++;
 	      if (uids_seen != uid_no)
 		continue;
 
 	      if (user_id->flags.revoked || user_id->flags.expired)
 		unusable = 1;
 
 	      break;
 	    }
 	}
 
       /* If UID_NO is non-zero, then the keyblock better have at least
 	 that many UIDs.  */
       log_assert (uids_seen == uid_no);
     }
 
   if (!unusable)
     unusable = pk_is_disabled (pk);
 
 leave:
   release_kbnode (keyblock);
   return unusable;
 }
 
 
 /* Search for keys matching some criteria.
 
    If RETCTX is not NULL, then the constructed context is returned in
    *RETCTX so that getpubkey_next can be used to get subsequent
    results.  In this case, getkey_end() must be used to free the
    search context.  If RETCTX is not NULL, then RET_KDBHD must be
    NULL.
 
    If NAMELIST is not NULL, then a search query is constructed using
    classify_user_id on each of the strings in the list.  (Recall: the
    database does an OR of the terms, not an AND.)  If NAMELIST is
    NULL, then all results are returned.
 
    If PK is not NULL, the public key of the first result is returned
    in *PK.  Note: PK->REQ_USAGE must be valid!!!  If PK->REQ_USAGE is
    set, it is used to filter the search results.  See the
    documentation for finish_lookup to understand exactly how this is
    used.  Note: The self-signed data has already been merged into the
    public key using merge_selfsigs.  Free *PK by calling
    release_public_key_parts (or, if PK was allocated using xfree, you
    can use free_public_key, which calls release_public_key_parts(PK)
    and then xfree(PK)).
 
    If WANT_SECRET is set, then only keys with an available secret key
    (either locally or via key registered on a smartcard) are returned.
 
    If INCLUDE_UNUSABLE is set, then unusable keys (see the
    documentation for skip_unusable for an exact definition) are
    skipped unless they are looked up by key id or by fingerprint.
 
    If RET_KB is not NULL, the keyblock is returned in *RET_KB.  This
    should be freed using release_kbnode().
 
    If RET_KDBHD is not NULL, then the new database handle used to
    conduct the search is returned in *RET_KDBHD.  This can be used to
    get subsequent results using keydb_search_next.  Note: in this
    case, no advanced filtering is done for subsequent results (e.g.,
    WANT_SECRET and PK->REQ_USAGE are not respected).
 
    This function returns 0 on success.  Otherwise, an error code is
    returned.  In particular, GPG_ERR_NO_PUBKEY or GPG_ERR_NO_SECKEY
    (if want_secret is set) is returned if the key is not found.  */
 static int
 key_byname (ctrl_t ctrl, GETKEY_CTX *retctx, strlist_t namelist,
 	    PKT_public_key *pk,
 	    int want_secret, int include_unusable,
 	    KBNODE * ret_kb, KEYDB_HANDLE * ret_kdbhd)
 {
   int rc = 0;
   int n;
   strlist_t r;
   GETKEY_CTX ctx;
   KBNODE help_kb = NULL;
   KBNODE found_key = NULL;
 
   if (retctx)
     {
       /* Reset the returned context in case of error.  */
       log_assert (!ret_kdbhd); /* Not allowed because the handle is stored
                                   in the context.  */
       *retctx = NULL;
     }
   if (ret_kdbhd)
     *ret_kdbhd = NULL;
 
   if (!namelist)
     /* No search terms: iterate over the whole DB.  */
     {
       ctx = xmalloc_clear (sizeof *ctx);
       ctx->nitems = 1;
       ctx->items[0].mode = KEYDB_SEARCH_MODE_FIRST;
       if (!include_unusable)
         {
           ctx->items[0].skipfnc = skip_unusable;
           ctx->items[0].skipfncvalue = ctrl;
         }
     }
   else
     {
       /* Build the search context.  */
       for (n = 0, r = namelist; r; r = r->next)
 	n++;
 
       /* CTX has space for a single search term at the end.  Thus, we
 	 need to allocate sizeof *CTX plus (n - 1) sizeof
 	 CTX->ITEMS.  */
       ctx = xmalloc_clear (sizeof *ctx + (n - 1) * sizeof ctx->items);
       ctx->nitems = n;
 
       for (n = 0, r = namelist; r; r = r->next, n++)
 	{
 	  gpg_error_t err;
 
 	  err = classify_user_id (r->d, &ctx->items[n], 1);
 
 	  if (ctx->items[n].exact)
 	    ctx->exact = 1;
 	  if (err)
 	    {
 	      xfree (ctx);
 	      return gpg_err_code (err); /* FIXME: remove gpg_err_code.  */
 	    }
 	  if (!include_unusable
 	      && ctx->items[n].mode != KEYDB_SEARCH_MODE_SHORT_KID
 	      && ctx->items[n].mode != KEYDB_SEARCH_MODE_LONG_KID
 	      && ctx->items[n].mode != KEYDB_SEARCH_MODE_FPR16
 	      && ctx->items[n].mode != KEYDB_SEARCH_MODE_FPR20
 	      && ctx->items[n].mode != KEYDB_SEARCH_MODE_FPR)
             {
               ctx->items[n].skipfnc = skip_unusable;
               ctx->items[n].skipfncvalue = ctrl;
             }
 	}
     }
 
   ctx->want_secret = want_secret;
   ctx->kr_handle = keydb_new ();
   if (!ctx->kr_handle)
     {
       rc = gpg_error_from_syserror ();
       getkey_end (ctrl, ctx);
       return rc;
     }
 
   if (!ret_kb)
     ret_kb = &help_kb;
 
   if (pk)
     {
       ctx->req_usage = pk->req_usage;
     }
 
   rc = lookup (ctrl, ctx, want_secret, ret_kb, &found_key);
   if (!rc && pk)
     {
       pk_from_block (pk, *ret_kb, found_key);
     }
 
   release_kbnode (help_kb);
 
   if (retctx) /* Caller wants the context.  */
     *retctx = ctx;
   else
     {
       if (ret_kdbhd)
 	{
 	  *ret_kdbhd = ctx->kr_handle;
 	  ctx->kr_handle = NULL;
 	}
       getkey_end (ctrl, ctx);
     }
 
   return rc;
 }
 
 
 /* Find a public key identified by NAME.
  *
  * If name appears to be a valid RFC822 mailbox (i.e., email address)
  * and auto key lookup is enabled (mode != GET_PUBKEY_NO_AKL), then
  * the specified auto key lookup methods (--auto-key-lookup) are used
  * to import the key into the local keyring.  Otherwise, just the
  * local keyring is consulted.
  *
  * MODE can be one of:
  *    GET_PUBKEY_NORMAL   - The standard mode
  *    GET_PUBKEY_NO_AKL   - The auto key locate functionality is
  *                          disabled and only the local key ring is
  *                          considered.  Note: the local key ring is
  *                          consulted even if local is not in the
  *                          auto-key-locate option list!
  *    GET_PUBKEY_NO_LOCAL - Only the auto key locate functionaly is
  *                          used and no local search is done.
  *
  * If RETCTX is not NULL, then the constructed context is returned in
  * *RETCTX so that getpubkey_next can be used to get subsequent
  * results.  In this case, getkey_end() must be used to free the
  * search context.  If RETCTX is not NULL, then RET_KDBHD must be
  * NULL.
  *
  * If PK is not NULL, the public key of the first result is returned
  * in *PK.  Note: PK->REQ_USAGE must be valid!!!  PK->REQ_USAGE is
  * passed through to the lookup function and is a mask of
  * PUBKEY_USAGE_SIG, PUBKEY_USAGE_ENC and PUBKEY_USAGE_CERT.  If this
  * is non-zero, only keys with the specified usage will be returned.
  * Note: The self-signed data has already been merged into the public
  * key using merge_selfsigs.  Free *PK by calling
  * release_public_key_parts (or, if PK was allocated using xfree, you
  * can use free_public_key, which calls release_public_key_parts(PK)
  * and then xfree(PK)).
  *
  * NAME is a string, which is turned into a search query using
  * classify_user_id.
  *
  * If RET_KEYBLOCK is not NULL, the keyblock is returned in
  * *RET_KEYBLOCK.  This should be freed using release_kbnode().
  *
  * If RET_KDBHD is not NULL, then the new database handle used to
  * conduct the search is returned in *RET_KDBHD.  This can be used to
  * get subsequent results using keydb_search_next or to modify the
  * returned record.  Note: in this case, no advanced filtering is done
  * for subsequent results (e.g., PK->REQ_USAGE is not respected).
  * Unlike RETCTX, this is always returned.
  *
  * If INCLUDE_UNUSABLE is set, then unusable keys (see the
  * documentation for skip_unusable for an exact definition) are
  * skipped unless they are looked up by key id or by fingerprint.
  *
  * This function returns 0 on success.  Otherwise, an error code is
  * returned.  In particular, GPG_ERR_NO_PUBKEY or GPG_ERR_NO_SECKEY
  * (if want_secret is set) is returned if the key is not found.  */
 int
 get_pubkey_byname (ctrl_t ctrl, enum get_pubkey_modes mode,
                    GETKEY_CTX * retctx, PKT_public_key * pk,
 		   const char *name, KBNODE * ret_keyblock,
 		   KEYDB_HANDLE * ret_kdbhd, int include_unusable)
 {
   int rc;
   strlist_t namelist = NULL;
   struct akl *akl;
   int is_mbox, is_fpr;
   KEYDB_SEARCH_DESC fprbuf;
   int nodefault = 0;
   int anylocalfirst = 0;
   int mechanism_type = AKL_NODEFAULT;
   size_t fprbuf_fprlen = 0;
 
   /* If RETCTX is not NULL, then RET_KDBHD must be NULL.  */
   log_assert (retctx == NULL || ret_kdbhd == NULL);
 
   if (retctx)
     *retctx = NULL;
 
   /* Does NAME appear to be a mailbox (mail address)?  */
   is_mbox = is_valid_mailbox (name);
   if (!is_mbox && *name == '<' && name[1] && name[strlen(name)-1]=='>'
       && name[1] != '>'
       && is_valid_mailbox_mem (name+1, strlen (name)-2))
     {
       /* The mailbox is in the form "<foo@example.org>" which is not
        * detected by is_valid_mailbox.  Set the flag but keep name as
        * it is because the bracketed name is actual the better
        * specification for a local search and the other methods
        * extract the mail address anyway.  */
       is_mbox = 1;
     }
 
   /* If we are called due to --locate-external-key Check whether NAME
    * is a fingerprint and then try to lookup that key by configured
    * method which support lookup by fingerprint.  FPRBUF carries the
    * parsed fingerpint iff IS_FPR is true.  */
   is_fpr = 0;
   if (!is_mbox && mode == GET_PUBKEY_NO_LOCAL)
     {
       if (!classify_user_id (name, &fprbuf, 1)
           && (fprbuf.mode == KEYDB_SEARCH_MODE_FPR16
               || fprbuf.mode == KEYDB_SEARCH_MODE_FPR20
               || fprbuf.mode == KEYDB_SEARCH_MODE_FPR))
         {
           /* Note: We should get rid of the FPR16 because we don't
            * support v3 keys anymore.  However, in 2.3 the fingerprint
            * code has already been reworked and thus it is
            * questionable whether we should really tackle this here.  */
           if (fprbuf.mode == KEYDB_SEARCH_MODE_FPR16)
             fprbuf_fprlen = 16;
           else
             fprbuf_fprlen = 20;
           is_fpr = 1;
         }
     }
 
   /* The auto-key-locate feature works as follows: there are a number
    * of methods to look up keys.  By default, the local keyring is
    * tried first.  Then, each method listed in the --auto-key-locate is
    * tried in the order it appears.
    *
    * This can be changed as follows:
    *
    *   - if nodefault appears anywhere in the list of options, then
    *     the local keyring is not tried first, or,
    *
    *   - if local appears anywhere in the list of options, then the
    *     local keyring is not tried first, but in the order in which
    *     it was listed in the --auto-key-locate option.
    *
    * Note: we only save the search context in RETCTX if the local
    * method is the first method tried (either explicitly or
    * implicitly).  */
   if (mode == GET_PUBKEY_NO_LOCAL)
     nodefault = 1;  /* Auto-key-locate but ignore "local".  */
   else if (mode != GET_PUBKEY_NO_AKL)
     {
       /* auto-key-locate is enabled.  */
 
       /* nodefault is true if "nodefault" or "local" appear.  */
       for (akl = opt.auto_key_locate; akl; akl = akl->next)
 	if (akl->type == AKL_NODEFAULT || akl->type == AKL_LOCAL)
 	  {
 	    nodefault = 1;
 	    break;
 	  }
       /* anylocalfirst is true if "local" appears before any other
 	 search methods (except "nodefault").  */
       for (akl = opt.auto_key_locate; akl; akl = akl->next)
 	if (akl->type != AKL_NODEFAULT)
 	  {
 	    if (akl->type == AKL_LOCAL)
 	      anylocalfirst = 1;
 	    break;
 	  }
     }
 
   if (!nodefault)
     {
       /* "nodefault" didn't occur.  Thus, "local" is implicitly the
        *  first method to try.  */
       anylocalfirst = 1;
     }
 
   if (mode == GET_PUBKEY_NO_LOCAL)
     {
       /* Force using the AKL.  If IS_MBOX is not set this is the final
        * error code.  */
       rc = GPG_ERR_NO_PUBKEY;
     }
   else if (nodefault && is_mbox)
     {
       /* Either "nodefault" or "local" (explicitly) appeared in the
        * auto key locate list and NAME appears to be an email address.
        * Don't try the local keyring.  */
       rc = GPG_ERR_NO_PUBKEY;
     }
   else
     {
       /* Either "nodefault" and "local" don't appear in the auto key
        * locate list (in which case we try the local keyring first) or
        * NAME does not appear to be an email address (in which case we
        * only try the local keyring).  In this case, lookup NAME in
        * the local keyring.  */
       add_to_strlist (&namelist, name);
       rc = key_byname (ctrl, retctx, namelist, pk, 0,
 		       include_unusable, ret_keyblock, ret_kdbhd);
     }
 
   /* If the requested name resembles a valid mailbox and automatic
      retrieval has been enabled, we try to import the key. */
   if (gpg_err_code (rc) == GPG_ERR_NO_PUBKEY
       && mode != GET_PUBKEY_NO_AKL
       && (is_mbox || is_fpr))
     {
       /* NAME wasn't present in the local keyring (or we didn't try
        * the local keyring).  Since the auto key locate feature is
        * enabled and NAME appears to be an email address, try the auto
        * locate feature.  */
       for (akl = opt.auto_key_locate; akl; akl = akl->next)
 	{
 	  unsigned char *fpr = NULL;
 	  size_t fpr_len;
 	  int did_akl_local = 0;
 	  int no_fingerprint = 0;
 	  const char *mechanism_string = "?";
 
           mechanism_type = akl->type;
 	  switch (mechanism_type)
 	    {
 	    case AKL_NODEFAULT:
 	      /* This is a dummy mechanism.  */
 	      mechanism_string = "";
 	      rc = GPG_ERR_NO_PUBKEY;
 	      break;
 
 	    case AKL_LOCAL:
               if (mode == GET_PUBKEY_NO_LOCAL)
                 {
                   /* Note that we get here in is_fpr more, so there is
                    * no extra check for it required.  */
                   mechanism_string = "";
                   rc = GPG_ERR_NO_PUBKEY;
                 }
               else
                 {
                   mechanism_string = "Local";
                   did_akl_local = 1;
                   if (retctx)
                     {
                       getkey_end (ctrl, *retctx);
                       *retctx = NULL;
                     }
                   add_to_strlist (&namelist, name);
                   rc = key_byname (ctrl, anylocalfirst ? retctx : NULL,
                                    namelist, pk, 0,
                                    include_unusable, ret_keyblock, ret_kdbhd);
                 }
 	      break;
 
 	    case AKL_CERT:
               if (is_fpr)
                 {
                   mechanism_string = "";
                   rc = GPG_ERR_NO_PUBKEY;
                 }
               else
                 {
                   mechanism_string = "DNS CERT";
                   glo_ctrl.in_auto_key_retrieve++;
                   rc = keyserver_import_cert (ctrl, name, 0, &fpr, &fpr_len);
                   glo_ctrl.in_auto_key_retrieve--;
                 }
               break;
 
 	    case AKL_PKA:
               if (is_fpr)
                 {
                   mechanism_string = "";
                   rc = GPG_ERR_NO_PUBKEY;
                 }
               else
                 {
                   mechanism_string = "PKA";
                   glo_ctrl.in_auto_key_retrieve++;
                   rc = keyserver_import_pka (ctrl, name, &fpr, &fpr_len);
                   glo_ctrl.in_auto_key_retrieve--;
                 }
               break;
 
 	    case AKL_DANE:
               if (is_fpr)
                 {
                   mechanism_string = "";
                   rc = GPG_ERR_NO_PUBKEY;
                 }
               else
                 {
                   mechanism_string = "DANE";
                   glo_ctrl.in_auto_key_retrieve++;
                   rc = keyserver_import_cert (ctrl, name, 1, &fpr, &fpr_len);
                   glo_ctrl.in_auto_key_retrieve--;
                 }
 	      break;
 
 	    case AKL_WKD:
               if (is_fpr)
                 {
                   mechanism_string = "";
                   rc = GPG_ERR_NO_PUBKEY;
                 }
               else
                 {
                   mechanism_string = "WKD";
                   glo_ctrl.in_auto_key_retrieve++;
                   rc = keyserver_import_wkd (ctrl, name, 0, &fpr, &fpr_len);
                   glo_ctrl.in_auto_key_retrieve--;
                 }
 	      break;
 
 	    case AKL_LDAP:
               if (is_fpr)
                 {
                   mechanism_string = "";
                   rc = GPG_ERR_NO_PUBKEY;
                 }
               else
                 {
                   mechanism_string = "LDAP";
                   glo_ctrl.in_auto_key_retrieve++;
                   rc = keyserver_import_ldap (ctrl, name, &fpr, &fpr_len);
                   glo_ctrl.in_auto_key_retrieve--;
                 }
               break;
 
 	    case AKL_NTDS:
 	      mechanism_string = "NTDS";
 	      glo_ctrl.in_auto_key_retrieve++;
               if (is_fpr)
                 rc = keyserver_import_fprint_ntds (ctrl,
                                                    fprbuf.u.fpr, fprbuf_fprlen);
               else
                 rc = keyserver_import_ntds (ctrl, name, &fpr, &fpr_len);
 	      glo_ctrl.in_auto_key_retrieve--;
 	      break;
 
 	    case AKL_KEYSERVER:
 	      /* Strictly speaking, we don't need to only use a valid
 	       * mailbox for the getname search, but it helps cut down
 	       * on the problem of searching for something like "john"
 	       * and getting a whole lot of keys back. */
 	      if (keyserver_any_configured (ctrl))
 		{
 		  mechanism_string = "keyserver";
 		  glo_ctrl.in_auto_key_retrieve++;
                   if (is_fpr)
                     {
                       rc = keyserver_import_fprint (ctrl,
                                                     fprbuf.u.fpr, fprbuf_fprlen,
                                                     opt.keyserver,
                                                     KEYSERVER_IMPORT_FLAG_LDAP);
                       /* Map error codes because Dirmngr returns NO
                        * DATA if the keyserver does not have the
                        * requested key.  It returns NO KEYSERVER if no
                        * LDAP keyservers are configured.  */
                       if (gpg_err_code (rc) == GPG_ERR_NO_DATA
                           || gpg_err_code (rc) == GPG_ERR_NO_KEYSERVER)
                         rc = gpg_error (GPG_ERR_NO_PUBKEY);
                     }
                   else
                     {
                       rc = keyserver_import_mbox (ctrl, name, &fpr, &fpr_len,
                                                   opt.keyserver);
                     }
 		  glo_ctrl.in_auto_key_retrieve--;
 		}
 	      else
 		{
 		  mechanism_string = "Unconfigured keyserver";
 		  rc = GPG_ERR_NO_PUBKEY;
 		}
 	      break;
 
 	    case AKL_SPEC:
 	      {
 		struct keyserver_spec *keyserver;
 
 		mechanism_string = akl->spec->uri;
 		keyserver = keyserver_match (akl->spec);
 		glo_ctrl.in_auto_key_retrieve++;
                 if (is_fpr)
                   {
                     rc = keyserver_import_fprint (ctrl,
                                                   fprbuf.u.fpr, fprbuf_fprlen,
                                                   opt.keyserver,
                                                   KEYSERVER_IMPORT_FLAG_LDAP);
                     if (gpg_err_code (rc) == GPG_ERR_NO_DATA
                         || gpg_err_code (rc) == GPG_ERR_NO_KEYSERVER)
                       rc = gpg_error (GPG_ERR_NO_PUBKEY);
                   }
                 else
                   {
                     rc = keyserver_import_mbox (ctrl, name,
                                                 &fpr, &fpr_len, keyserver);
                   }
 		glo_ctrl.in_auto_key_retrieve--;
 	      }
 	      break;
 	    }
 
 	  /* Use the fingerprint of the key that we actually fetched.
 	   * This helps prevent problems where the key that we fetched
 	   * doesn't have the same name that we used to fetch it.  In
 	   * the case of CERT and PKA, this is an actual security
 	   * requirement as the URL might point to a key put in by an
 	   * attacker.  By forcing the use of the fingerprint, we
 	   * won't use the attacker's key here. */
 	  if (!rc && (fpr || is_fpr))
 	    {
 	      char fpr_string[MAX_FINGERPRINT_LEN * 2 + 1];
 
               if (is_fpr)
                 {
                   log_assert (fprbuf_fprlen <= MAX_FINGERPRINT_LEN);
                   bin2hex (fprbuf.u.fpr, fprbuf_fprlen, fpr_string);
                 }
               else
                 {
                   log_assert (fpr_len <= MAX_FINGERPRINT_LEN);
                   bin2hex (fpr, fpr_len, fpr_string);
                 }
 
 	      if (opt.verbose)
 		log_info ("auto-key-locate found fingerprint %s\n",
 			  fpr_string);
 
 	      free_strlist (namelist);
 	      namelist = NULL;
 	      add_to_strlist (&namelist, fpr_string);
 	    }
 	  else if (!rc && !fpr && !did_akl_local)
             { /* The acquisition method said no failure occurred, but
                * it didn't return a fingerprint.  That's a failure.  */
               no_fingerprint = 1;
 	      rc = GPG_ERR_NO_PUBKEY;
 	    }
 	  xfree (fpr);
 	  fpr = NULL;
 
 	  if (!rc && !did_akl_local)
             { /* There was no error and we didn't do a local lookup.
 	       * This means that we imported a key into the local
 	       * keyring.  Try to read the imported key from the
 	       * keyring.  */
 	      if (retctx)
 		{
 		  getkey_end (ctrl, *retctx);
 		  *retctx = NULL;
 		}
 	      rc = key_byname (ctrl, anylocalfirst ? retctx : NULL,
 			       namelist, pk, 0,
 			       include_unusable, ret_keyblock, ret_kdbhd);
 	    }
 	  if (!rc)
 	    {
 	      /* Key found.  */
               if (opt.verbose)
                 log_info (_("automatically retrieved '%s' via %s\n"),
                           name, mechanism_string);
 	      break;
 	    }
 	  if ((gpg_err_code (rc) != GPG_ERR_NO_PUBKEY
                || opt.verbose || no_fingerprint) && *mechanism_string)
 	    log_info (_("error retrieving '%s' via %s: %s\n"),
 		      name, mechanism_string,
 		      no_fingerprint ? _("No fingerprint") : gpg_strerror (rc));
 	}
     }
 
   if (rc && retctx)
     {
       getkey_end (ctrl, *retctx);
       *retctx = NULL;
     }
 
   if (retctx && *retctx)
     {
       log_assert (!(*retctx)->extra_list);
       (*retctx)->extra_list = namelist;
       (*retctx)->found_via_akl = mechanism_type;
     }
   else
     free_strlist (namelist);
 
   return rc;
 }
 
 
 
 
 /* Comparison machinery for get_best_pubkey_byname.  */
 
 /* First we have a struct to cache computed information about the key
  * in question.  */
 struct pubkey_cmp_cookie
 {
   int valid;			/* Is this cookie valid?  */
   PKT_public_key key;		/* The key.  */
   PKT_user_id *uid;		/* The matching UID packet.  */
   unsigned int validity;	/* Computed validity of (KEY, UID).  */
   u32 creation_time;		/* Creation time of the newest subkey
                                    capable of encryption.  */
 };
 
 
 /* Then we have a series of helper functions.  */
 static int
 key_is_ok (const PKT_public_key *key)
 {
   return (! key->has_expired && ! key->flags.revoked
           && key->flags.valid && ! key->flags.disabled);
 }
 
 
 static int
 uid_is_ok (const PKT_public_key *key, const PKT_user_id *uid)
 {
   return key_is_ok (key) && ! uid->flags.revoked;
 }
 
 
 static int
 subkey_is_ok (const PKT_public_key *sub)
 {
   return ! sub->flags.revoked && sub->flags.valid && ! sub->flags.disabled;
 }
 
 /* Return true if KEYBLOCK has only expired encryption subkyes.  Note
  * that the function returns false if the key has no encryption
  * subkeys at all or the subkeys are revoked.  */
 static int
 only_expired_enc_subkeys (kbnode_t keyblock)
 {
   kbnode_t node;
   PKT_public_key *sub;
   int any = 0;
 
   for (node = find_next_kbnode (keyblock, PKT_PUBLIC_SUBKEY);
        node; node = find_next_kbnode (node, PKT_PUBLIC_SUBKEY))
     {
       sub = node->pkt->pkt.public_key;
 
       if (!(sub->pubkey_usage & PUBKEY_USAGE_ENC))
         continue;
 
       if (!subkey_is_ok (sub))
         continue;
 
       any = 1;
       if (!sub->has_expired)
         return 0;
     }
 
   return any? 1 : 0;
 }
 
 /* Finally this function compares a NEW key to the former candidate
  * OLD.  Returns < 0 if the old key is worse, > 0 if the old key is
  * better, == 0 if it is a tie.  */
 static int
 pubkey_cmp (ctrl_t ctrl, const char *name, struct pubkey_cmp_cookie *old,
             struct pubkey_cmp_cookie *new, KBNODE new_keyblock)
 {
   kbnode_t n;
 
   new->creation_time = 0;
   for (n = find_next_kbnode (new_keyblock, PKT_PUBLIC_SUBKEY);
        n; n = find_next_kbnode (n, PKT_PUBLIC_SUBKEY))
     {
       PKT_public_key *sub = n->pkt->pkt.public_key;
 
       if ((sub->pubkey_usage & PUBKEY_USAGE_ENC) == 0)
         continue;
 
       if (! subkey_is_ok (sub))
         continue;
 
       if (sub->timestamp > new->creation_time)
         new->creation_time = sub->timestamp;
     }
 
   for (n = find_next_kbnode (new_keyblock, PKT_USER_ID);
        n; n = find_next_kbnode (n, PKT_USER_ID))
     {
       PKT_user_id *uid = n->pkt->pkt.user_id;
       char *mbox = mailbox_from_userid (uid->name);
       int match = mbox ? strcasecmp (name, mbox) == 0 : 0;
 
       xfree (mbox);
       if (! match)
         continue;
 
       new->uid = scopy_user_id (uid);
       new->validity =
         get_validity (ctrl, new_keyblock, &new->key, uid, NULL, 0) & TRUST_MASK;
       new->valid = 1;
 
       if (! old->valid)
         return -1;	/* No OLD key.  */
 
       if (! uid_is_ok (&old->key, old->uid) && uid_is_ok (&new->key, uid))
         return -1;	/* Validity of the NEW key is better.  */
 
       if (old->validity < new->validity)
         return -1;	/* Validity of the NEW key is better.  */
 
       if (old->validity == new->validity && uid_is_ok (&new->key, uid)
           && old->creation_time < new->creation_time)
         return -1;	/* Both keys are of the same validity, but the
                            NEW key is newer.  */
     }
 
   /* Stick with the OLD key.  */
   return 1;
 }
 
 
 /* This function works like get_pubkey_byname, but if the name
  * resembles a mail address, the results are ranked and only the best
  * result is returned.  */
 gpg_error_t
 get_best_pubkey_byname (ctrl_t ctrl, enum get_pubkey_modes mode,
                         GETKEY_CTX *retctx, PKT_public_key *pk,
                         const char *name, KBNODE *ret_keyblock,
                         int include_unusable)
 {
   gpg_error_t err;
   struct getkey_ctx_s *ctx = NULL;
   int is_mbox;
   int wkd_tried = 0;
 
   if (retctx)
     *retctx = NULL;
 
   is_mbox = is_valid_mailbox (name);
   if (!is_mbox && *name == '<' && name[1] && name[strlen(name)-1]=='>'
       && name[1] != '>'
       && is_valid_mailbox_mem (name+1, strlen (name)-2))
     {
       /* The mailbox is in the form "<foo@example.org>" which is not
        * detected by is_valid_mailbox.  Set the flag but keep name as
        * it is because get_pubkey_byname does an is_valid_mailbox_mem
        * itself.  */
       is_mbox = 1;
     }
 
  start_over:
   if (ctx)  /* Clear  in case of a start over.  */
     {
       if (ret_keyblock)
         {
           release_kbnode (*ret_keyblock);
           *ret_keyblock = NULL;
         }
       getkey_end (ctrl, ctx);
       ctx = NULL;
     }
   err = get_pubkey_byname (ctrl, mode,
                            &ctx, pk, name, ret_keyblock,
                            NULL, include_unusable);
   if (err)
     {
       goto leave;
     }
 
   /* If the keyblock was retrieved from the local database and the key
    * has expired, do further checks.  However, we can do this only if
    * the caller requested a keyblock.  */
   if (is_mbox && ctx && ctx->found_via_akl == AKL_LOCAL && ret_keyblock)
     {
       u32 now = make_timestamp ();
       PKT_public_key *pk2 = (*ret_keyblock)->pkt->pkt.public_key;
       int found;
 
       /* If the key has expired and its origin was the WKD then try to
        * get a fresh key from the WKD.  We also try this if the key
        * has any only expired encryption subkeys.  In case we checked
        * for a fresh copy in the last 3 hours we won't do that again.
        * Unfortunately that does not yet work because KEYUPDATE is
        * only updated during import iff the key has actually changed
        * (see import.c:import_one).  */
       if (!wkd_tried && pk2->keyorg == KEYORG_WKD
           && (pk2->keyupdate + 3*3600) < now
           && (pk2->has_expired || only_expired_enc_subkeys (*ret_keyblock)))
         {
           if (opt.verbose)
             log_info (_("checking for a fresh copy of an expired key via %s\n"),
                       "WKD");
           wkd_tried = 1;
           glo_ctrl.in_auto_key_retrieve++;
           found = !keyserver_import_wkd (ctrl, name, 0, NULL, NULL);
           glo_ctrl.in_auto_key_retrieve--;
           if (found)
             goto start_over;
         }
     }
 
   if (is_mbox && ctx)
     {
       /* Rank results and return only the most relevant key.  */
       struct pubkey_cmp_cookie best = { 0 };
       struct pubkey_cmp_cookie new = { 0 };
       kbnode_t new_keyblock;
 
       while (getkey_next (ctrl, ctx, &new.key, &new_keyblock) == 0)
         {
           int diff = pubkey_cmp (ctrl, name, &best, &new, new_keyblock);
           release_kbnode (new_keyblock);
           if (diff < 0)
             {
               /* New key is better.  */
               release_public_key_parts (&best.key);
               free_user_id (best.uid);
               best = new;
             }
           else if (diff > 0)
             {
               /* Old key is better.  */
               release_public_key_parts (&new.key);
               free_user_id (new.uid);
             }
           else
             {
               /* A tie.  Keep the old key.  */
               release_public_key_parts (&new.key);
               free_user_id (new.uid);
             }
           new.uid = NULL;
         }
       getkey_end (ctrl, ctx);
       ctx = NULL;
       free_user_id (best.uid);
       best.uid = NULL;
 
       if (best.valid)
         {
           if (retctx || ret_keyblock)
             {
               ctx = xtrycalloc (1, sizeof **retctx);
               if (! ctx)
                 err = gpg_error_from_syserror ();
               else
                 {
                   ctx->kr_handle = keydb_new ();
                   if (! ctx->kr_handle)
                     {
                       err = gpg_error_from_syserror ();
                       xfree (ctx);
                       ctx = NULL;
                       if (retctx)
                         *retctx = NULL;
                     }
                   else
                     {
                       u32 *keyid = pk_keyid (&best.key);
                       ctx->exact = 1;
                       ctx->nitems = 1;
                       ctx->items[0].mode = KEYDB_SEARCH_MODE_LONG_KID;
                       ctx->items[0].u.kid[0] = keyid[0];
                       ctx->items[0].u.kid[1] = keyid[1];
 
                       if (ret_keyblock)
                         {
                           release_kbnode (*ret_keyblock);
                           *ret_keyblock = NULL;
                           err = getkey_next (ctrl, ctx, NULL, ret_keyblock);
                         }
                     }
                 }
             }
 
           if (pk)
             {
               release_public_key_parts (pk);
               *pk = best.key;
             }
           else
             release_public_key_parts (&best.key);
         }
     }
 
   if (err && ctx)
     {
       getkey_end (ctrl, ctx);
       ctx = NULL;
     }
 
   if (retctx && ctx)
     {
       *retctx = ctx;
       ctx = NULL;
     }
 
  leave:
   getkey_end (ctrl, ctx);
   return err;
 }
 
 
 
 /* Get a public key from a file.
  *
  * PK is the buffer to store the key.  The caller needs to make sure
  * that PK->REQ_USAGE is valid.  PK->REQ_USAGE is passed through to
  * the lookup function and is a mask of PUBKEY_USAGE_SIG,
  * PUBKEY_USAGE_ENC and PUBKEY_USAGE_CERT.  If this is non-zero, only
  * keys with the specified usage will be returned.
  *
  * FNAME is the file name.  That file should contain exactly one
  * keyblock.
  *
  * This function returns 0 on success.  Otherwise, an error code is
  * returned.  In particular, GPG_ERR_NO_PUBKEY is returned if the key
  * is not found.  If R_KEYBLOCK is not NULL and a key was found the
  * keyblock is stored there; otherwiese NULL is stored there.
  *
  * The self-signed data has already been merged into the public key
  * using merge_selfsigs.  The caller must release the content of PK by
  * calling release_public_key_parts (or, if PK was malloced, using
  * free_public_key).
  */
 gpg_error_t
 get_pubkey_fromfile (ctrl_t ctrl, PKT_public_key *pk, const char *fname,
                      kbnode_t *r_keyblock)
 {
   gpg_error_t err;
   kbnode_t keyblock;
   kbnode_t found_key;
   unsigned int infoflags;
 
   if (r_keyblock)
     *r_keyblock = NULL;
 
   err = read_key_from_file_or_buffer (ctrl, fname, NULL, 0, &keyblock);
   if (!err)
     {
       /* Warning: node flag bits 0 and 1 should be preserved by
        * merge_selfsigs.  FIXME: Check whether this still holds. */
       merge_selfsigs (ctrl, keyblock);
       found_key = finish_lookup (keyblock, pk->req_usage, 0, 0, &infoflags);
       print_status_key_considered (keyblock, infoflags);
       if (found_key)
         pk_from_block (pk, keyblock, found_key);
       else
         err = gpg_error (GPG_ERR_UNUSABLE_PUBKEY);
     }
 
   if (!err && r_keyblock)
     *r_keyblock = keyblock;
   else
     release_kbnode (keyblock);
   return err;
 }
 
 
 /* Return a public key from the buffer (BUFFER, BUFLEN).  The key is
  * onlyretruned if it matches the keyid given in WANT_KEYID. On
  * success the key is stored at the caller provided PKBUF structure.
  * The caller must release the content of PK by calling
  * release_public_key_parts (or, if PKBUF was malloced, using
  * free_public_key).  If R_KEYBLOCK is not NULL the full keyblock is
  * also stored there.  */
 gpg_error_t
 get_pubkey_from_buffer (ctrl_t ctrl, PKT_public_key *pkbuf,
                         const void *buffer, size_t buflen, u32 *want_keyid,
                         kbnode_t *r_keyblock)
 {
   gpg_error_t err;
   kbnode_t keyblock;
   kbnode_t node;
   PKT_public_key *pk;
 
   if (r_keyblock)
     *r_keyblock = NULL;
 
   err = read_key_from_file_or_buffer (ctrl, NULL, buffer, buflen, &keyblock);
   if (!err)
     {
       merge_selfsigs (ctrl, keyblock);
       for (node = keyblock; node; node = node->next)
         {
           if (node->pkt->pkttype == PKT_PUBLIC_KEY
               || node->pkt->pkttype == PKT_PUBLIC_SUBKEY)
             {
               pk = node->pkt->pkt.public_key;
               keyid_from_pk (pk, NULL);
               if (pk->keyid[0] == want_keyid[0]
                   && pk->keyid[1] == want_keyid[1])
                 break;
             }
         }
       if (node)
         copy_public_key (pkbuf, pk);
       else
         err = gpg_error (GPG_ERR_NO_PUBKEY);
     }
 
   if (!err && r_keyblock)
     *r_keyblock = keyblock;
   else
     release_kbnode (keyblock);
   return err;
 }
 
 
 /* Lookup a key with the specified fingerprint.
  *
  * If PK is not NULL, the public key of the first result is returned
  * in *PK.  Note: this function does an exact search and thus the
  * returned public key may be a subkey rather than the primary key.
  * Note: The self-signed data has already been merged into the public
  * key using merge_selfsigs.  Free *PK by calling
  * release_public_key_parts (or, if PK was allocated using xmalloc, you
  * can use free_public_key, which calls release_public_key_parts(PK)
  * and then xfree(PK)).
  *
  * If PK->REQ_USAGE is set, it is used to filter the search results.
  * Thus, if PK is not NULL, PK->REQ_USAGE must be valid!  See the
  * documentation for finish_lookup to understand exactly how this is
  * used.
  *
  * If R_KEYBLOCK is not NULL, then the first result's keyblock is
  * returned in *R_KEYBLOCK.  This should be freed using
  * release_kbnode().
  *
  * FPRINT is a byte array whose contents is the fingerprint to use as
  * the search term.  FPRINT_LEN specifies the length of the
  * fingerprint (in bytes).  Currently, only 16 and 20-byte
  * fingerprints are supported.
  *
  * FIXME: We should replace this with the _byname function.  This can
  * be done by creating a userID conforming to the unified fingerprint
  * style.  */
 int
 get_pubkey_byfprint (ctrl_t ctrl, PKT_public_key *pk, kbnode_t *r_keyblock,
 		     const byte * fprint, size_t fprint_len)
 {
   int rc;
 
   if (r_keyblock)
     *r_keyblock = NULL;
 
   if (fprint_len == 20 || fprint_len == 16)
     {
       struct getkey_ctx_s ctx;
       KBNODE kb = NULL;
       KBNODE found_key = NULL;
 
       memset (&ctx, 0, sizeof ctx);
       ctx.exact = 1;
       ctx.not_allocated = 1;
       /* FIXME: We should get the handle from the cache like we do in
        * get_pubkey.  */
       ctx.kr_handle = keydb_new ();
       if (!ctx.kr_handle)
         return gpg_error_from_syserror ();
 
       ctx.nitems = 1;
       ctx.items[0].mode = fprint_len == 16 ? KEYDB_SEARCH_MODE_FPR16
 	: KEYDB_SEARCH_MODE_FPR20;
       memcpy (ctx.items[0].u.fpr, fprint, fprint_len);
       if (pk)
         ctx.req_usage = pk->req_usage;
       rc = lookup (ctrl, &ctx, 0, &kb, &found_key);
       if (!rc && pk)
 	pk_from_block (pk, kb, found_key);
       if (!rc && r_keyblock)
 	{
 	  *r_keyblock = kb;
 	  kb = NULL;
 	}
       release_kbnode (kb);
       getkey_end (ctrl, &ctx);
     }
   else
     rc = GPG_ERR_GENERAL; /* Oops */
   return rc;
 }
 
 
 /* This function is similar to get_pubkey_byfprint, but it doesn't
  * merge the self-signed data into the public key and subkeys or into
  * the user ids.  It also doesn't add the key to the user id cache.
  * Further, this function ignores PK->REQ_USAGE.
  *
  * This function is intended to avoid recursion and, as such, should
  * only be used in very specific situations.
  *
  * Like get_pubkey_byfprint, PK may be NULL.  In that case, this
  * function effectively just checks for the existence of the key.  */
 gpg_error_t
 get_pubkey_byfprint_fast (PKT_public_key * pk,
 			  const byte * fprint, size_t fprint_len)
 {
   gpg_error_t err;
   KBNODE keyblock;
 
   err = get_keyblock_byfprint_fast (&keyblock, NULL, fprint, fprint_len, 0);
   if (!err)
     {
       if (pk)
         copy_public_key (pk, keyblock->pkt->pkt.public_key);
       release_kbnode (keyblock);
     }
 
   return err;
 }
 
 
 /* This function is similar to get_pubkey_byfprint_fast but returns a
  * keydb handle at R_HD and the keyblock at R_KEYBLOCK.  R_KEYBLOCK or
  * R_HD may be NULL.  If LOCK is set the handle has been opend in
  * locked mode and keydb_disable_caching () has been called.  On error
  * R_KEYBLOCK is set to NULL but R_HD must be released by the caller;
  * it may have a value of NULL, though.  This allows to do an insert
  * operation on a locked keydb handle.  */
 gpg_error_t
 get_keyblock_byfprint_fast (kbnode_t *r_keyblock, KEYDB_HANDLE *r_hd,
                             const byte *fprint, size_t fprint_len, int lock)
 {
   gpg_error_t err;
   KEYDB_HANDLE hd;
   kbnode_t keyblock;
   byte fprbuf[MAX_FINGERPRINT_LEN];
   int i;
 
   if (r_keyblock)
     *r_keyblock = NULL;
   if (r_hd)
     *r_hd = NULL;
 
   for (i = 0; i < MAX_FINGERPRINT_LEN && i < fprint_len; i++)
     fprbuf[i] = fprint[i];
   while (i < MAX_FINGERPRINT_LEN)
     fprbuf[i++] = 0;
 
   hd = keydb_new ();
   if (!hd)
     return gpg_error_from_syserror ();
 
   if (lock)
     {
       err = keydb_lock (hd);
       if (err)
         {
           /* If locking did not work, we better don't return a handle
            * at all - there was a reason that locking has been
            * requested.  */
           keydb_release (hd);
           return err;
         }
       keydb_disable_caching (hd);
     }
 
   /* Fo all other errors we return the handle.  */
   if (r_hd)
     *r_hd = hd;
 
   err = keydb_search_fpr (hd, fprbuf);
   if (gpg_err_code (err) == GPG_ERR_NOT_FOUND)
     {
       if (!r_hd)
         keydb_release (hd);
       return gpg_error (GPG_ERR_NO_PUBKEY);
     }
   err = keydb_get_keyblock (hd, &keyblock);
   if (err)
     {
       log_error ("keydb_get_keyblock failed: %s\n", gpg_strerror (err));
       if (!r_hd)
         keydb_release (hd);
       return gpg_error (GPG_ERR_NO_PUBKEY);
     }
 
   log_assert (keyblock->pkt->pkttype == PKT_PUBLIC_KEY
               || keyblock->pkt->pkttype == PKT_PUBLIC_SUBKEY);
 
   /* Not caching key here since it won't have all of the fields
      properly set. */
 
   if (r_keyblock)
     *r_keyblock = keyblock;
   else
     release_kbnode (keyblock);
 
   if (!r_hd)
     keydb_release (hd);
 
   return 0;
 }
 
 
 const char *
 parse_def_secret_key (ctrl_t ctrl)
 {
   KEYDB_HANDLE hd = NULL;
   strlist_t t;
   static int warned;
 
   for (t = opt.def_secret_key; t; t = t->next)
     {
       gpg_error_t err;
       KEYDB_SEARCH_DESC desc;
       KBNODE kb;
       KBNODE node;
 
       err = classify_user_id (t->d, &desc, 1);
       if (err)
         {
           log_error (_("secret key \"%s\" not found: %s\n"),
                      t->d, gpg_strerror (err));
           if (!opt.quiet)
             log_info (_("(check argument of option '%s')\n"), "--default-key");
           continue;
         }
 
       if (! hd)
         {
           hd = keydb_new ();
           if (!hd)
             return NULL;
         }
       else
         keydb_search_reset (hd);
 
 
       err = keydb_search (hd, &desc, 1, NULL);
       if (gpg_err_code (err) == GPG_ERR_NOT_FOUND)
         continue;
 
       if (err)
         {
           log_error (_("key \"%s\" not found: %s\n"), t->d, gpg_strerror (err));
           t = NULL;
           break;
         }
 
       err = keydb_get_keyblock (hd, &kb);
       if (err)
         {
           log_error (_("error reading keyblock: %s\n"),
                      gpg_strerror (err));
           continue;
         }
 
       merge_selfsigs (ctrl, kb);
 
       err = gpg_error (GPG_ERR_NO_SECKEY);
       node = kb;
       do
         {
           PKT_public_key *pk = node->pkt->pkt.public_key;
 
           /* Check if the key is valid.  */
           if (pk->flags.revoked)
             {
               if (DBG_LOOKUP)
                 log_debug ("not using %s as default key, %s",
                            keystr_from_pk (pk), "revoked");
               continue;
             }
           if (pk->has_expired)
             {
               if (DBG_LOOKUP)
                 log_debug ("not using %s as default key, %s",
                            keystr_from_pk (pk), "expired");
               continue;
             }
           if (pk_is_disabled (pk))
             {
               if (DBG_LOOKUP)
                 log_debug ("not using %s as default key, %s",
                            keystr_from_pk (pk), "disabled");
               continue;
             }
 
           if (agent_probe_secret_key (ctrl, pk))
             {
               /* This is a valid key.  */
               err = 0;
               break;
             }
         }
       while ((node = find_next_kbnode (node, PKT_PUBLIC_SUBKEY)));
 
       release_kbnode (kb);
       if (err)
         {
           if (! warned && ! opt.quiet)
             {
               log_info (_("Warning: not using '%s' as default key: %s\n"),
                         t->d, gpg_strerror (GPG_ERR_NO_SECKEY));
               print_reported_error (err, GPG_ERR_NO_SECKEY);
             }
         }
       else
         {
           if (! warned && ! opt.quiet)
             log_info (_("using \"%s\" as default secret key for signing\n"),
                       t->d);
           break;
         }
     }
 
   if (! warned && opt.def_secret_key && ! t)
     log_info (_("all values passed to '%s' ignored\n"),
               "--default-key");
 
   warned = 1;
 
   if (hd)
     keydb_release (hd);
 
   if (t)
     return t->d;
   return NULL;
 }
 
 
 /* Look up a secret key.
  *
  * If PK is not NULL, the public key of the first result is returned
  * in *PK.  Note: PK->REQ_USAGE must be valid!!!  If PK->REQ_USAGE is
  * set, it is used to filter the search results.  See the
  * documentation for finish_lookup to understand exactly how this is
  * used.  Note: The self-signed data has already been merged into the
  * public key using merge_selfsigs.  Free *PK by calling
  * release_public_key_parts (or, if PK was allocated using xfree, you
  * can use free_public_key, which calls release_public_key_parts(PK)
  * and then xfree(PK)).
  *
  * If --default-key was set, then the specified key is looked up.  (In
  * this case, the default key is returned even if it is considered
  * unusable.  See the documentation for skip_unusable for exactly what
  * this means.)
  *
  * Otherwise, this initiates a DB scan that returns all keys that are
  * usable (see previous paragraph for exactly what usable means) and
  * for which a secret key is available.
  *
  * This function returns the first match.  Additional results can be
  * returned using getkey_next.  */
 gpg_error_t
 get_seckey_default (ctrl_t ctrl, PKT_public_key *pk)
 {
   gpg_error_t err;
   strlist_t namelist = NULL;
   int include_unusable = 1;
 
 
   const char *def_secret_key = parse_def_secret_key (ctrl);
   if (def_secret_key)
     add_to_strlist (&namelist, def_secret_key);
   else
     include_unusable = 0;
 
   err = key_byname (ctrl, NULL, namelist, pk, 1, include_unusable, NULL, NULL);
 
   free_strlist (namelist);
 
   return err;
 }
 
 
 
 /* Search for keys matching some criteria.
  *
  * If RETCTX is not NULL, then the constructed context is returned in
  * *RETCTX so that getpubkey_next can be used to get subsequent
  * results.  In this case, getkey_end() must be used to free the
  * search context.  If RETCTX is not NULL, then RET_KDBHD must be
  * NULL.
  *
  * If PK is not NULL, the public key of the first result is returned
  * in *PK.  Note: PK->REQ_USAGE must be valid!!!  If PK->REQ_USAGE is
  * set, it is used to filter the search results.  See the
  * documentation for finish_lookup to understand exactly how this is
  * used.  Note: The self-signed data has already been merged into the
  * public key using merge_selfsigs.  Free *PK by calling
  * release_public_key_parts (or, if PK was allocated using xfree, you
  * can use free_public_key, which calls release_public_key_parts(PK)
  * and then xfree(PK)).
  *
  * If NAMES is not NULL, then a search query is constructed using
  * classify_user_id on each of the strings in the list.  (Recall: the
  * database does an OR of the terms, not an AND.)  If NAMES is
  * NULL, then all results are returned.
  *
  * If WANT_SECRET is set, then only keys with an available secret key
  * (either locally or via key registered on a smartcard) are returned.
  *
  * This function does not skip unusable keys (see the documentation
  * for skip_unusable for an exact definition).
  *
  * If RET_KEYBLOCK is not NULL, the keyblock is returned in
  * *RET_KEYBLOCK.  This should be freed using release_kbnode().
  *
  * This function returns 0 on success.  Otherwise, an error code is
  * returned.  In particular, GPG_ERR_NO_PUBKEY or GPG_ERR_NO_SECKEY
  * (if want_secret is set) is returned if the key is not found.  */
 gpg_error_t
 getkey_bynames (ctrl_t ctrl, getkey_ctx_t *retctx, PKT_public_key *pk,
                 strlist_t names, int want_secret, kbnode_t *ret_keyblock)
 {
   return key_byname (ctrl, retctx, names, pk, want_secret, 1,
                      ret_keyblock, NULL);
 }
 
 
 /* Search for one key matching some criteria.
  *
  * If RETCTX is not NULL, then the constructed context is returned in
  * *RETCTX so that getpubkey_next can be used to get subsequent
  * results.  In this case, getkey_end() must be used to free the
  * search context.  If RETCTX is not NULL, then RET_KDBHD must be
  * NULL.
  *
  * If PK is not NULL, the public key of the first result is returned
  * in *PK.  Note: PK->REQ_USAGE must be valid!!!  If PK->REQ_USAGE is
  * set, it is used to filter the search results.  See the
  * documentation for finish_lookup to understand exactly how this is
  * used.  Note: The self-signed data has already been merged into the
  * public key using merge_selfsigs.  Free *PK by calling
  * release_public_key_parts (or, if PK was allocated using xfree, you
  * can use free_public_key, which calls release_public_key_parts(PK)
  * and then xfree(PK)).
  *
  * If NAME is not NULL, then a search query is constructed using
  * classify_user_id on the string.  In this case, even unusable keys
  * (see the documentation for skip_unusable for an exact definition of
  * unusable) are returned.  Otherwise, if --default-key was set, then
  * that key is returned (even if it is unusable).  If neither of these
  * conditions holds, then the first usable key is returned.
  *
  * If WANT_SECRET is set, then only keys with an available secret key
  * (either locally or via key registered on a smartcard) are returned.
  *
  * This function does not skip unusable keys (see the documentation
  * for skip_unusable for an exact definition).
  *
  * If RET_KEYBLOCK is not NULL, the keyblock is returned in
  * *RET_KEYBLOCK.  This should be freed using release_kbnode().
  *
  * This function returns 0 on success.  Otherwise, an error code is
  * returned.  In particular, GPG_ERR_NO_PUBKEY or GPG_ERR_NO_SECKEY
  * (if want_secret is set) is returned if the key is not found.
  *
  * FIXME: We also have the get_pubkey_byname function which has a
  * different semantic.  Should be merged with this one.  */
 gpg_error_t
 getkey_byname (ctrl_t ctrl, getkey_ctx_t *retctx, PKT_public_key *pk,
                const char *name, int want_secret, kbnode_t *ret_keyblock)
 {
   gpg_error_t err;
   strlist_t namelist = NULL;
   int with_unusable = 1;
   const char *def_secret_key = NULL;
 
   if (want_secret && !name)
     def_secret_key = parse_def_secret_key (ctrl);
 
   if (want_secret && !name && def_secret_key)
     add_to_strlist (&namelist, def_secret_key);
   else if (name)
     add_to_strlist (&namelist, name);
   else
     with_unusable = 0;
 
   err = key_byname (ctrl, retctx, namelist, pk, want_secret, with_unusable,
                     ret_keyblock, NULL);
 
   /* FIXME: Check that we really return GPG_ERR_NO_SECKEY if
      WANT_SECRET has been used.  */
 
   free_strlist (namelist);
 
   return err;
 }
 
 
 /* Return the next search result.
  *
  * If PK is not NULL, the public key of the next result is returned in
  * *PK.  Note: The self-signed data has already been merged into the
  * public key using merge_selfsigs.  Free *PK by calling
  * release_public_key_parts (or, if PK was allocated using xmalloc, you
  * can use free_public_key, which calls release_public_key_parts(PK)
  * and then xfree(PK)).
  *
  * RET_KEYBLOCK can be given as NULL; if it is not NULL it the entire
  * found keyblock is returned which must be released with
  * release_kbnode.  If the function returns an error NULL is stored at
  * RET_KEYBLOCK.
  *
  * The self-signed data has already been merged into the public key
  * using merge_selfsigs.  */
 gpg_error_t
 getkey_next (ctrl_t ctrl, getkey_ctx_t ctx,
              PKT_public_key *pk, kbnode_t *ret_keyblock)
 {
   int rc; /* Fixme:  Make sure this is proper gpg_error */
   KBNODE keyblock = NULL;
   KBNODE found_key = NULL;
 
   /* We need to disable the caching so that for an exact key search we
      won't get the result back from the cache and thus end up in an
      endless loop.  The endless loop can occur, because the cache is
      used without respecting the current file pointer!  */
   keydb_disable_caching (ctx->kr_handle);
 
   /* FOUND_KEY is only valid as long as RET_KEYBLOCK is.  If the
    * caller wants PK, but not RET_KEYBLOCK, we need hand in our own
    * keyblock.  */
   if (pk && ret_keyblock == NULL)
       ret_keyblock = &keyblock;
 
   rc = lookup (ctrl, ctx, ctx->want_secret,
                ret_keyblock, pk ? &found_key : NULL);
   if (!rc && pk)
     {
       log_assert (found_key);
       pk_from_block (pk, NULL, found_key);
       release_kbnode (keyblock);
     }
 
   return rc;
 }
 
 
 /* Release any resources used by a key listing context.  This must be
  * called on the context returned by, e.g., getkey_byname.  */
 void
 getkey_end (ctrl_t ctrl, getkey_ctx_t ctx)
 {
   if (ctx)
     {
 #ifdef HAVE_W32_SYSTEM
 
       /* FIXME: This creates a big regression for Windows because the
        * keyring is only released after the global ctrl is released.
        * So if an operation does a getkey and then tries to modify the
        * keyring it will fail on Windows with a sharing violation.  We
        * need to modify all keyring write operations to also take the
        * ctrl and close the cached_getkey_kdb handle to make writing
        * work.  See: GnuPG-bug-id: 3097  */
       (void)ctrl;
       keydb_release (ctx->kr_handle);
 
 #else /*!HAVE_W32_SYSTEM*/
 
       if (ctrl && !ctrl->cached_getkey_kdb)
         ctrl->cached_getkey_kdb = ctx->kr_handle;
       else
         keydb_release (ctx->kr_handle);
 
 #endif /*!HAVE_W32_SYSTEM*/
 
       free_strlist (ctx->extra_list);
       if (!ctx->not_allocated)
 	xfree (ctx);
     }
 }
 
 
 
 /************************************************
  ************* Merging stuff ********************
  ************************************************/
 
 /* Set the mainkey_id fields for all keys in KEYBLOCK.  This is
  * usually done by merge_selfsigs but at some places we only need the
  * main_kid not a full merge.  The function also guarantees that all
  * pk->keyids are computed.  */
 void
 setup_main_keyids (kbnode_t keyblock)
 {
   u32 kid[2], mainkid[2];
   kbnode_t kbctx, node;
   PKT_public_key *pk;
 
   if (keyblock->pkt->pkttype != PKT_PUBLIC_KEY)
     BUG ();
   pk = keyblock->pkt->pkt.public_key;
 
   keyid_from_pk (pk, mainkid);
   for (kbctx=NULL; (node = walk_kbnode (keyblock, &kbctx, 0)); )
     {
       if (!(node->pkt->pkttype == PKT_PUBLIC_KEY
             || node->pkt->pkttype == PKT_PUBLIC_SUBKEY))
         continue;
       pk = node->pkt->pkt.public_key;
       keyid_from_pk (pk, kid); /* Make sure pk->keyid is set.  */
       if (!pk->main_keyid[0] && !pk->main_keyid[1])
         {
           pk->main_keyid[0] = mainkid[0];
           pk->main_keyid[1] = mainkid[1];
         }
     }
 }
 
 
 /* KEYBLOCK corresponds to a public key block.  This function merges
  * much of the information from the self-signed data into the public
  * key, public subkey and user id data structures.  If you use the
  * high-level search API (e.g., get_pubkey) for looking up key blocks,
  * then you don't need to call this function.  This function is
  * useful, however, if you change the keyblock, e.g., by adding or
  * removing a self-signed data packet.  */
 void
 merge_keys_and_selfsig (ctrl_t ctrl, kbnode_t keyblock)
 {
   if (!keyblock)
     ;
   else if (keyblock->pkt->pkttype == PKT_PUBLIC_KEY)
     merge_selfsigs (ctrl, keyblock);
   else
     log_debug ("FIXME: merging secret key blocks is not anymore available\n");
 }
 
 
 /* This function parses the key flags and returns PUBKEY_USAGE_ flags.  */
 unsigned int
 parse_key_usage (PKT_signature * sig)
 {
   int key_usage = 0;
   const byte *p;
   size_t n;
   byte flags;
 
   p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_KEY_FLAGS, &n);
   if (p && n)
     {
       /* First octet of the keyflags.  */
       flags = *p;
 
       if (flags & 1)
 	{
 	  key_usage |= PUBKEY_USAGE_CERT;
 	  flags &= ~1;
 	}
 
       if (flags & 2)
 	{
 	  key_usage |= PUBKEY_USAGE_SIG;
 	  flags &= ~2;
 	}
 
       /* We do not distinguish between encrypting communications and
          encrypting storage. */
       if (flags & (0x04 | 0x08))
 	{
 	  key_usage |= PUBKEY_USAGE_ENC;
 	  flags &= ~(0x04 | 0x08);
 	}
 
       if (flags & 0x20)
 	{
 	  key_usage |= PUBKEY_USAGE_AUTH;
 	  flags &= ~0x20;
 	}
 
       if ((flags & 0x80))
 	{
 	  key_usage |= PUBKEY_USAGE_GROUP;
 	  flags &= ~0x80;
 	}
 
       if (flags)
 	key_usage |= PUBKEY_USAGE_UNKNOWN;
 
       n--;
       p++;
       if (n)
         {
           flags = *p;
           if ((flags & 0x04))
             key_usage |= PUBKEY_USAGE_RENC;
           if ((flags & 0x08))
             key_usage |= PUBKEY_USAGE_TIME;
         }
 
       if (!key_usage)
 	key_usage |= PUBKEY_USAGE_NONE;
 
     }
   else if (p) /* Key flags of length zero.  */
     key_usage |= PUBKEY_USAGE_NONE;
 
   /* We set PUBKEY_USAGE_UNKNOWN to indicate that this key has a
      capability that we do not handle.  This serves to distinguish
      between a zero key usage which we handle as the default
      capabilities for that algorithm, and a usage that we do not
      handle.  Likewise we use PUBKEY_USAGE_NONE to indicate that
      key_flags have been given but they do not specify any usage.  */
 
   return key_usage;
 }
 
 
 /* Apply information from SIGNODE (which is the valid self-signature
  * associated with that UID) to the UIDNODE:
  * - wether the UID has been revoked
  * - assumed creation date of the UID
  * - temporary store the keyflags here
  * - temporary store the key expiration time here
  * - mark whether the primary user ID flag hat been set.
  * - store the preferences
  */
 static void
 fixup_uidnode (KBNODE uidnode, KBNODE signode, u32 keycreated)
 {
   PKT_user_id *uid = uidnode->pkt->pkt.user_id;
   PKT_signature *sig = signode->pkt->pkt.signature;
   const byte *p, *sym, *aead, *hash, *zip;
   size_t n, nsym, naead, nhash, nzip;
 
   sig->flags.chosen_selfsig = 1;/* We chose this one. */
   uid->created = 0;		/* Not created == invalid. */
   if (IS_UID_REV (sig))
     {
       uid->flags.revoked = 1;
       return; /* Has been revoked.  */
     }
   else
     uid->flags.revoked = 0;
 
   uid->expiredate = sig->expiredate;
 
   if (sig->flags.expired)
     {
       uid->flags.expired = 1;
       return; /* Has expired.  */
     }
   else
     uid->flags.expired = 0;
 
   uid->created = sig->timestamp; /* This one is okay. */
   uid->selfsigversion = sig->version;
   /* If we got this far, it's not expired :) */
   uid->flags.expired = 0;
 
   /* Store the key flags in the helper variable for later processing.  */
   uid->help_key_usage = parse_key_usage (sig);
 
   /* Ditto for the key expiration.  */
   p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_KEY_EXPIRE, NULL);
   if (p && buf32_to_u32 (p))
     uid->help_key_expire = keycreated + buf32_to_u32 (p);
   else
     uid->help_key_expire = 0;
 
   /* Set the primary user ID flag - we will later wipe out some
    * of them to only have one in our keyblock.  */
   uid->flags.primary = 0;
   p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_PRIMARY_UID, NULL);
   if (p && *p)
     uid->flags.primary = 2;
 
   /* We could also query this from the unhashed area if it is not in
    * the hased area and then later try to decide which is the better
    * there should be no security problem with this.
    * For now we only look at the hashed one.  */
 
   /* Now build the preferences list.  These must come from the
      hashed section so nobody can modify the ciphers a key is
      willing to accept.  */
   p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_PREF_SYM, &n);
   sym = p;
   nsym = p ? n : 0;
   p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_PREF_AEAD, &n);
   aead = p;
   naead = p ? n : 0;
   p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_PREF_HASH, &n);
   hash = p;
   nhash = p ? n : 0;
   p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_PREF_COMPR, &n);
   zip = p;
   nzip = p ? n : 0;
   if (uid->prefs)
     xfree (uid->prefs);
   n = nsym + naead + nhash + nzip;
   if (!n)
     uid->prefs = NULL;
   else
     {
       uid->prefs = xmalloc (sizeof (*uid->prefs) * (n + 1));
       n = 0;
       for (; nsym; nsym--, n++)
 	{
 	  uid->prefs[n].type = PREFTYPE_SYM;
 	  uid->prefs[n].value = *sym++;
 	}
       for (; naead; naead--, n++)
 	{
 	  uid->prefs[n].type = PREFTYPE_AEAD;
 	  uid->prefs[n].value = *aead++;
 	}
       for (; nhash; nhash--, n++)
 	{
 	  uid->prefs[n].type = PREFTYPE_HASH;
 	  uid->prefs[n].value = *hash++;
 	}
       for (; nzip; nzip--, n++)
 	{
 	  uid->prefs[n].type = PREFTYPE_ZIP;
 	  uid->prefs[n].value = *zip++;
 	}
       uid->prefs[n].type = PREFTYPE_NONE; /* End of list marker  */
       uid->prefs[n].value = 0;
     }
 
   /* See whether we have the MDC feature.  */
   uid->flags.mdc = 0;
   p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_FEATURES, &n);
   if (p && n && (p[0] & 0x01))
     uid->flags.mdc = 1;
 
   /* See whether we have the AEAD feature.  */
   uid->flags.aead = 0;
   p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_FEATURES, &n);
   if (p && n && (p[0] & 0x02))
     uid->flags.aead = 1;
 
   /* And the keyserver modify flag.  */
   uid->flags.ks_modify = 1;
   p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_KS_FLAGS, &n);
   if (p && n && (p[0] & 0x80))
     uid->flags.ks_modify = 0;
 }
 
 static void
 sig_to_revoke_info (PKT_signature * sig, struct revoke_info *rinfo)
 {
   rinfo->date = sig->timestamp;
   rinfo->algo = sig->pubkey_algo;
   rinfo->keyid[0] = sig->keyid[0];
   rinfo->keyid[1] = sig->keyid[1];
 }
 
 
 /* Given a keyblock, parse the key block and extract various pieces of
  * information and save them with the primary key packet and the user
  * id packets.  For instance, some information is stored in signature
  * packets.  We find the latest such valid packet (since the user can
  * change that information) and copy its contents into the
  * PKT_public_key.
  *
  * Note that R_REVOKED may be set to 0, 1 or 2.
  *
  * This function fills in the following fields in the primary key's
  * keyblock:
  *
  *   main_keyid          (computed)
  *   revkey / numrevkeys (derived from self signed key data)
  *   flags.valid         (whether we have at least 1 self-sig)
  *   flags.maybe_revoked (whether a designed revoked the key, but
  *                        we are missing the key to check the sig)
  *   selfsigversion      (highest version of any valid self-sig)
  *   pubkey_usage        (derived from most recent self-sig or most
  *                        recent user id)
  *   has_expired         (various sources)
  *   expiredate          (various sources)
  *
  * See the documentation for fixup_uidnode for how the user id packets
  * are modified.  In addition to that the primary user id's is_primary
  * field is set to 1 and the other user id's is_primary are set to 0.
  */
 static void
 merge_selfsigs_main (ctrl_t ctrl, kbnode_t keyblock, int *r_revoked,
 		     struct revoke_info *rinfo)
 {
   PKT_public_key *pk = NULL;
   KBNODE k;
   u32 kid[2];
   u32 sigdate, uiddate, uiddate2;
   KBNODE signode, uidnode, uidnode2;
   u32 curtime = make_timestamp ();
   unsigned int key_usage = 0;
   u32 keytimestamp = 0;  /* Creation time of the key.  */
   u32 key_expire = 0;
   int key_expire_seen = 0;
   byte sigversion = 0;
 
   *r_revoked = 0;
   memset (rinfo, 0, sizeof (*rinfo));
 
   /* Section 11.1 of RFC 4880 determines the order of packets within a
    * message.  There are three sections, which must occur in the
    * following order: the public key, the user ids and user attributes
    * and the subkeys.  Within each section, each primary packet (e.g.,
    * a user id packet) is followed by one or more signature packets,
    * which modify that packet.  */
 
   /* According to Section 11.1 of RFC 4880, the public key must be the
      first packet.  Note that parse_keyblock_image ensures that the
      first packet is the public key.  */
   if (keyblock->pkt->pkttype != PKT_PUBLIC_KEY)
     BUG ();
   pk = keyblock->pkt->pkt.public_key;
   keytimestamp = pk->timestamp;
 
   keyid_from_pk (pk, kid);
   pk->main_keyid[0] = kid[0];
   pk->main_keyid[1] = kid[1];
 
   if (pk->version < 4)
     {
       /* Before v4 the key packet itself contains the expiration date
        * and there was no way to change it, so we start with the one
        * from the key packet.  We do not support v3 keys anymore but
        * we keep the code in case a future key versions introduces a
        * hard expire time again. */
       key_expire = pk->max_expiredate;
       key_expire_seen = 1;
     }
 
   /* First pass:
    *
    * - Find the latest direct key self-signature.  We assume that the
    *   newest one overrides all others.
    *
    * - Determine whether the key has been revoked.
    *
    * - Gather all revocation keys (unlike other data, we don't just
    *   take them from the latest self-signed packet).
    *
    * - Determine max (sig[...]->version).
    */
 
   /* Reset this in case this key was already merged. */
   xfree (pk->revkey);
   pk->revkey = NULL;
   pk->numrevkeys = 0;
 
   signode = NULL;
   sigdate = 0; /* Helper variable to find the latest signature.  */
 
   /* According to Section 11.1 of RFC 4880, the public key comes first
    * and is immediately followed by any signature packets that modify
    * it.  */
   for (k = keyblock;
        k && k->pkt->pkttype != PKT_USER_ID
 	 && k->pkt->pkttype != PKT_ATTRIBUTE
 	 && k->pkt->pkttype != PKT_PUBLIC_SUBKEY;
        k = k->next)
     {
       if (k->pkt->pkttype == PKT_SIGNATURE)
 	{
 	  PKT_signature *sig = k->pkt->pkt.signature;
 	  if (sig->keyid[0] == kid[0] && sig->keyid[1] == kid[1])
 	    { /* Self sig.  */
 
 	      if (check_key_signature (ctrl, keyblock, k, NULL))
 		; /* Signature did not verify.  */
 	      else if (IS_KEY_REV (sig))
 		{
 		  /* Key has been revoked - there is no way to
 		   * override such a revocation, so we theoretically
 		   * can stop now.  We should not cope with expiration
 		   * times for revocations here because we have to
 		   * assume that an attacker can generate all kinds of
 		   * signatures.  However due to the fact that the key
 		   * has been revoked it does not harm either and by
 		   * continuing we gather some more info on that
 		   * key.  */
 		  *r_revoked = 1;
 		  sig_to_revoke_info (sig, rinfo);
 		}
 	      else if (IS_KEY_SIG (sig))
 		{
 		  /* Add the indicated revocations keys from all
 		   * signatures not just the latest.  We do this
 		   * because you need multiple 1F sigs to properly
 		   * handle revocation keys (PGP does it this way, and
 		   * a revocation key could be sensitive and hence in
 		   * a different signature).  */
 		  if (sig->revkey)
 		    {
 		      int i;
 
 		      pk->revkey =
 			xrealloc (pk->revkey, sizeof (struct revocation_key) *
 				  (pk->numrevkeys + sig->numrevkeys));
 
 		      for (i = 0; i < sig->numrevkeys; i++)
 			memcpy (&pk->revkey[pk->numrevkeys++],
 				&sig->revkey[i],
 				sizeof (struct revocation_key));
 		    }
 
 		  if (sig->timestamp >= sigdate)
 		    { /* This is the latest signature so far.  */
 
 		      if (sig->flags.expired)
 			; /* Signature has expired - ignore it.  */
 		      else
 			{
 			  sigdate = sig->timestamp;
 			  signode = k;
 			  if (sig->version > sigversion)
 			    sigversion = sig->version;
 
 			}
 		    }
 		}
 	    }
 	}
     }
 
   /* Remove dupes from the revocation keys.  */
   if (pk->revkey)
     {
       int i, j, x, changed = 0;
 
       for (i = 0; i < pk->numrevkeys; i++)
 	{
 	  for (j = i + 1; j < pk->numrevkeys; j++)
 	    {
 	      if (memcmp (&pk->revkey[i], &pk->revkey[j],
 			  sizeof (struct revocation_key)) == 0)
 		{
 		  /* remove j */
 
 		  for (x = j; x < pk->numrevkeys - 1; x++)
 		    pk->revkey[x] = pk->revkey[x + 1];
 
 		  pk->numrevkeys--;
 		  j--;
 		  changed = 1;
 		}
 	    }
 	}
 
       if (changed)
 	pk->revkey = xrealloc (pk->revkey,
 			       pk->numrevkeys *
 			       sizeof (struct revocation_key));
     }
 
   /* SIGNODE is the direct key signature packet (sigclass 0x1f) with
    * the latest creation time.  Extract some information from it.  */
   if (signode)
     {
       /* Some information from a direct key signature take precedence
        * over the same information given in UID sigs.  */
       PKT_signature *sig = signode->pkt->pkt.signature;
       const byte *p;
 
       key_usage = parse_key_usage (sig);
 
       p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_KEY_EXPIRE, NULL);
       if (p && buf32_to_u32 (p))
 	{
 	  key_expire = keytimestamp + buf32_to_u32 (p);
 	  key_expire_seen = 1;
 	}
 
       /* Mark that key as valid: One direct key signature should
        * render a key as valid.  */
       pk->flags.valid = 1;
     }
 
   /* Pass 1.5: Look for key revocation signatures that were not made
    * by the key (i.e. did a revocation key issue a revocation for
    * us?).  Only bother to do this if there is a revocation key in the
    * first place and we're not revoked already.  */
 
   if (!*r_revoked && pk->revkey)
     for (k = keyblock; k && k->pkt->pkttype != PKT_USER_ID; k = k->next)
       {
 	if (k->pkt->pkttype == PKT_SIGNATURE)
 	  {
 	    PKT_signature *sig = k->pkt->pkt.signature;
 
 	    if (IS_KEY_REV (sig) &&
 		(sig->keyid[0] != kid[0] || sig->keyid[1] != kid[1]))
 	      {
 		int rc = check_revocation_keys (ctrl, pk, sig);
 		if (rc == 0)
 		  {
 		    *r_revoked = 2;
 		    sig_to_revoke_info (sig, rinfo);
 		    /* Don't continue checking since we can't be any
 		     * more revoked than this.  */
 		    break;
 		  }
 		else if (gpg_err_code (rc) == GPG_ERR_NO_PUBKEY)
 		  pk->flags.maybe_revoked = 1;
 
 		/* A failure here means the sig did not verify, was
 		 * not issued by a revocation key, or a revocation
 		 * key loop was broken.  If a revocation key isn't
 		 * findable, however, the key might be revoked and
 		 * we don't know it.  */
 
 		/* Fixme: In the future handle subkey and cert
 		 * revocations?  PGP doesn't, but it's in 2440.  */
 	      }
 	  }
       }
 
   /* Second pass: Look at the self-signature of all user IDs.  */
 
   /* According to RFC 4880 section 11.1, user id and attribute packets
    * are in the second section, after the public key packet and before
    * the subkey packets.  */
   signode = uidnode = NULL;
   sigdate = 0; /* Helper variable to find the latest signature in one UID. */
   for (k = keyblock; k && k->pkt->pkttype != PKT_PUBLIC_SUBKEY; k = k->next)
     {
       if (k->pkt->pkttype == PKT_USER_ID || k->pkt->pkttype == PKT_ATTRIBUTE)
 	{ /* New user id packet.  */
 
           /* Apply the data from the most recent self-signed packet to
 	   * the preceding user id packet.  */
 	  if (uidnode && signode)
 	    {
 	      fixup_uidnode (uidnode, signode, keytimestamp);
 	      pk->flags.valid = 1;
 	    }
 
 	  /* Clear SIGNODE.  The only relevant self-signed data for
 	   * UIDNODE follows it.  */
 	  if (k->pkt->pkttype == PKT_USER_ID)
 	    uidnode = k;
 	  else
 	    uidnode = NULL;
 
 	  signode = NULL;
 	  sigdate = 0;
 	}
       else if (k->pkt->pkttype == PKT_SIGNATURE && uidnode)
 	{
 	  PKT_signature *sig = k->pkt->pkt.signature;
 	  if (sig->keyid[0] == kid[0] && sig->keyid[1] == kid[1])
 	    {
 	      if (check_key_signature (ctrl, keyblock, k, NULL))
 		;		/* signature did not verify */
 	      else if ((IS_UID_SIG (sig) || IS_UID_REV (sig))
 		       && sig->timestamp >= sigdate)
 		{
 		  /* Note: we allow invalidation of cert revocations
 		   * by a newer signature.  An attacker can't use this
 		   * because a key should be revoked with a key revocation.
 		   * The reason why we have to allow for that is that at
 		   * one time an email address may become invalid but later
 		   * the same email address may become valid again (hired,
 		   * fired, hired again).  */
 
 		  sigdate = sig->timestamp;
 		  signode = k;
 		  signode->pkt->pkt.signature->flags.chosen_selfsig = 0;
 		  if (sig->version > sigversion)
 		    sigversion = sig->version;
 		}
 	    }
 	}
     }
   if (uidnode && signode)
     {
       fixup_uidnode (uidnode, signode, keytimestamp);
       pk->flags.valid = 1;
     }
 
   /* If the key isn't valid yet, and we have
    * --allow-non-selfsigned-uid set, then force it valid. */
   if (!pk->flags.valid && opt.allow_non_selfsigned_uid)
     {
       if (opt.verbose)
 	log_info (_("Invalid key %s made valid by"
 		    " --allow-non-selfsigned-uid\n"), keystr_from_pk (pk));
       pk->flags.valid = 1;
     }
 
   /* The key STILL isn't valid, so try and find an ultimately
    * trusted signature. */
   if (!pk->flags.valid)
     {
       uidnode = NULL;
 
       for (k = keyblock; k && k->pkt->pkttype != PKT_PUBLIC_SUBKEY;
 	   k = k->next)
 	{
 	  if (k->pkt->pkttype == PKT_USER_ID)
 	    uidnode = k;
 	  else if (k->pkt->pkttype == PKT_SIGNATURE && uidnode)
 	    {
 	      PKT_signature *sig = k->pkt->pkt.signature;
 
 	      if (sig->keyid[0] != kid[0] || sig->keyid[1] != kid[1])
 		{
 		  PKT_public_key *ultimate_pk;
 
 		  ultimate_pk = xmalloc_clear (sizeof (*ultimate_pk));
 
 		  /* We don't want to use the full get_pubkey to avoid
 		   * infinite recursion in certain cases.  There is no
 		   * reason to check that an ultimately trusted key is
 		   * still valid - if it has been revoked the user
 		   * should also remove the ultimate trust flag.  */
 		  if (get_pubkey_fast (ultimate_pk, sig->keyid) == 0
 		      && check_key_signature2 (ctrl,
                                                keyblock, k, ultimate_pk,
 					       NULL, NULL, NULL, NULL) == 0
 		      && get_ownertrust (ctrl, ultimate_pk) == TRUST_ULTIMATE)
 		    {
 		      free_public_key (ultimate_pk);
 		      pk->flags.valid = 1;
 		      break;
 		    }
 
 		  free_public_key (ultimate_pk);
 		}
 	    }
 	}
     }
 
   /* Record the highest selfsig version so we know if this is a v3 key
    * through and through, or a v3 key with a v4 selfsig somewhere.
    * This is useful in a few places to know if the key must be treated
    * as PGP2-style or OpenPGP-style.  Note that a selfsig revocation
    * with a higher version number will also raise this value.  This is
    * okay since such a revocation must be issued by the user (i.e. it
    * cannot be issued by someone else to modify the key behavior.) */
 
   pk->selfsigversion = sigversion;
 
   /* Now that we had a look at all user IDs we can now get some
    * information from those user IDs.  */
 
   if (!key_usage)
     {
       /* Find the latest user ID with key flags set. */
       uiddate = 0; /* Helper to find the latest user ID.  */
       for (k = keyblock; k && k->pkt->pkttype != PKT_PUBLIC_SUBKEY;
 	   k = k->next)
 	{
 	  if (k->pkt->pkttype == PKT_USER_ID)
 	    {
 	      PKT_user_id *uid = k->pkt->pkt.user_id;
 
 	      if (uid->help_key_usage
                   && (uid->created > uiddate || (!uid->created && !uiddate)))
 		{
 		  key_usage = uid->help_key_usage;
 		  uiddate = uid->created;
 		}
 	    }
 	}
     }
 
   if (!key_usage)
     {
       /* No key flags at all: get it from the algo.  */
-      key_usage = openpgp_pk_algo_usage (pk->pubkey_algo);
+      key_usage = (openpgp_pk_algo_usage (pk->pubkey_algo)
+                   & PUBKEY_USAGE_BASIC_MASK);
     }
   else
     {
       /* Check that the usage matches the usage as given by the algo.  */
       int x = openpgp_pk_algo_usage (pk->pubkey_algo);
       if (x) /* Mask it down to the actual allowed usage.  */
 	key_usage &= x;
     }
 
   /* Whatever happens, it's a primary key, so it can certify. */
   pk->pubkey_usage = key_usage | PUBKEY_USAGE_CERT;
 
   if (!key_expire_seen)
     {
       /* Find the latest valid user ID with a key expiration set.
        * This may be a different one than from usage computation above
        * because some user IDs may have no expiration date set.  */
       uiddate = 0;
       for (k = keyblock; k && k->pkt->pkttype != PKT_PUBLIC_SUBKEY;
 	   k = k->next)
 	{
 	  if (k->pkt->pkttype == PKT_USER_ID)
 	    {
 	      PKT_user_id *uid = k->pkt->pkt.user_id;
 	      if (uid->help_key_expire
                   && (uid->created > uiddate || (!uid->created && !uiddate)))
 		{
 		  key_expire = uid->help_key_expire;
 		  uiddate = uid->created;
 		}
 	    }
 	}
     }
 
   /* Currently only the not anymore supported v3 keys have a maximum
    * expiration date, but future key versions may get this feature again. */
   if (key_expire == 0
       || (pk->max_expiredate && key_expire > pk->max_expiredate))
     key_expire = pk->max_expiredate;
 
   pk->has_expired = key_expire >= curtime ? 0 : key_expire;
   pk->expiredate = key_expire;
 
   /* Fixme: we should see how to get rid of the expiretime fields but
    * this needs changes at other places too.  */
 
   /* And now find the real primary user ID and delete all others.  */
   uiddate = uiddate2 = 0;
   uidnode = uidnode2 = NULL;
   for (k = keyblock; k && k->pkt->pkttype != PKT_PUBLIC_SUBKEY; k = k->next)
     {
       if (k->pkt->pkttype == PKT_USER_ID && !k->pkt->pkt.user_id->attrib_data)
 	{
 	  PKT_user_id *uid = k->pkt->pkt.user_id;
 	  if (uid->flags.primary)
 	    {
 	      if (uid->created > uiddate)
 		{
 		  uiddate = uid->created;
 		  uidnode = k;
 		}
 	      else if (uid->created == uiddate && uidnode)
 		{
 		  /* The dates are equal, so we need to do a different
 		   * (and arbitrary) comparison.  This should rarely,
 		   * if ever, happen.  It's good to try and guarantee
 		   * that two different GnuPG users with two different
 		   * keyrings at least pick the same primary.  */
 		  if (cmp_user_ids (uid, uidnode->pkt->pkt.user_id) > 0)
 		    uidnode = k;
 		}
 	    }
 	  else
 	    {
 	      if (uid->created > uiddate2)
 		{
 		  uiddate2 = uid->created;
 		  uidnode2 = k;
 		}
 	      else if (uid->created == uiddate2 && uidnode2)
 		{
 		  if (cmp_user_ids (uid, uidnode2->pkt->pkt.user_id) > 0)
 		    uidnode2 = k;
 		}
 	    }
 	}
     }
   if (uidnode)
     {
       for (k = keyblock; k && k->pkt->pkttype != PKT_PUBLIC_SUBKEY;
 	   k = k->next)
 	{
 	  if (k->pkt->pkttype == PKT_USER_ID &&
 	      !k->pkt->pkt.user_id->attrib_data)
 	    {
 	      PKT_user_id *uid = k->pkt->pkt.user_id;
 	      if (k != uidnode)
 		uid->flags.primary = 0;
 	    }
 	}
     }
   else if (uidnode2)
     {
       /* None is flagged primary - use the latest user ID we have,
        * and disambiguate with the arbitrary packet comparison. */
       uidnode2->pkt->pkt.user_id->flags.primary = 1;
     }
   else
     {
       /* None of our uids were self-signed, so pick the one that
        * sorts first to be the primary.  This is the best we can do
        * here since there are no self sigs to date the uids. */
 
       uidnode = NULL;
 
       for (k = keyblock; k && k->pkt->pkttype != PKT_PUBLIC_SUBKEY;
 	   k = k->next)
 	{
 	  if (k->pkt->pkttype == PKT_USER_ID
 	      && !k->pkt->pkt.user_id->attrib_data)
 	    {
 	      if (!uidnode)
 		{
 		  uidnode = k;
 		  uidnode->pkt->pkt.user_id->flags.primary = 1;
 		  continue;
 		}
 	      else
 		{
 		  if (cmp_user_ids (k->pkt->pkt.user_id,
 				    uidnode->pkt->pkt.user_id) > 0)
 		    {
 		      uidnode->pkt->pkt.user_id->flags.primary = 0;
 		      uidnode = k;
 		      uidnode->pkt->pkt.user_id->flags.primary = 1;
 		    }
 		  else
                     {
                       /* just to be safe: */
                       k->pkt->pkt.user_id->flags.primary = 0;
                     }
 		}
 	    }
 	}
     }
 }
 
 
 /* Convert a buffer to a signature.  Useful for 0x19 embedded sigs.
  * Caller must free the signature when they are done. */
 static PKT_signature *
 buf_to_sig (const byte * buf, size_t len)
 {
   PKT_signature *sig = xmalloc_clear (sizeof (PKT_signature));
   IOBUF iobuf = iobuf_temp_with_content (buf, len);
   int save_mode = set_packet_list_mode (0);
 
   if (parse_signature (iobuf, PKT_SIGNATURE, len, sig) != 0)
     {
       free_seckey_enc (sig);
       sig = NULL;
     }
 
   set_packet_list_mode (save_mode);
   iobuf_close (iobuf);
 
   return sig;
 }
 
 
 /* Use the self-signed data to fill in various fields in subkeys.
  *
  * KEYBLOCK is the whole keyblock.  SUBNODE is the subkey to fill in.
  *
  * Sets the following fields on the subkey:
  *
  *   main_keyid
  *   flags.valid        if the subkey has a valid self-sig binding
  *   flags.revoked
  *   flags.backsig
  *   pubkey_usage
  *   has_expired
  *   expired_date
  *
  * On this subkey's most revent valid self-signed packet, the
  * following field is set:
  *
  *   flags.chosen_selfsig
  */
 static void
 merge_selfsigs_subkey (ctrl_t ctrl, kbnode_t keyblock, kbnode_t subnode)
 {
   PKT_public_key *mainpk = NULL, *subpk = NULL;
   PKT_signature *sig;
   KBNODE k;
   u32 mainkid[2];
   u32 sigdate = 0;
   KBNODE signode;
   u32 curtime = make_timestamp ();
   unsigned int key_usage = 0;
   u32 keytimestamp = 0;
   u32 key_expire = 0;
   const byte *p;
 
   if (subnode->pkt->pkttype != PKT_PUBLIC_SUBKEY)
     BUG ();
   mainpk = keyblock->pkt->pkt.public_key;
   if (mainpk->version < 4)
     return;/* (actually this should never happen) */
   keyid_from_pk (mainpk, mainkid);
   subpk = subnode->pkt->pkt.public_key;
   keytimestamp = subpk->timestamp;
 
   subpk->flags.valid = 0;
   subpk->flags.exact = 0;
   subpk->main_keyid[0] = mainpk->main_keyid[0];
   subpk->main_keyid[1] = mainpk->main_keyid[1];
 
   /* Find the latest key binding self-signature.  */
   signode = NULL;
   sigdate = 0; /* Helper to find the latest signature.  */
   for (k = subnode->next; k && k->pkt->pkttype != PKT_PUBLIC_SUBKEY;
        k = k->next)
     {
       if (k->pkt->pkttype == PKT_SIGNATURE)
 	{
 	  sig = k->pkt->pkt.signature;
 	  if (sig->keyid[0] == mainkid[0] && sig->keyid[1] == mainkid[1])
 	    {
 	      if (check_key_signature (ctrl, keyblock, k, NULL))
 		; /* Signature did not verify.  */
 	      else if (IS_SUBKEY_REV (sig))
 		{
 		  /* Note that this means that the date on a
 		   * revocation sig does not matter - even if the
 		   * binding sig is dated after the revocation sig,
 		   * the subkey is still marked as revoked.  This
 		   * seems ok, as it is just as easy to make new
 		   * subkeys rather than re-sign old ones as the
 		   * problem is in the distribution.  Plus, PGP (7)
 		   * does this the same way.  */
 		  subpk->flags.revoked = 1;
 		  sig_to_revoke_info (sig, &subpk->revoked);
 		  /* Although we could stop now, we continue to
 		   * figure out other information like the old expiration
 		   * time.  */
 		}
 	      else if (IS_SUBKEY_SIG (sig) && sig->timestamp >= sigdate)
 		{
 		  if (sig->flags.expired)
 		    ; /* Signature has expired - ignore it.  */
 		  else
 		    {
 		      sigdate = sig->timestamp;
 		      signode = k;
 		      signode->pkt->pkt.signature->flags.chosen_selfsig = 0;
 		    }
 		}
 	    }
 	}
     }
 
   /* No valid key binding.  */
   if (!signode)
     return;
 
   sig = signode->pkt->pkt.signature;
   sig->flags.chosen_selfsig = 1; /* So we know which selfsig we chose later.  */
 
   key_usage = parse_key_usage (sig);
   if (!key_usage)
     {
       /* No key flags at all: get it from the algo.  */
-      key_usage = openpgp_pk_algo_usage (subpk->pubkey_algo);
+      key_usage = (openpgp_pk_algo_usage (subpk->pubkey_algo)
+                   & PUBKEY_USAGE_BASIC_MASK);
     }
   else
     {
       /* Check that the usage matches the usage as given by the algo.  */
       int x = openpgp_pk_algo_usage (subpk->pubkey_algo);
       if (x) /* Mask it down to the actual allowed usage.  */
 	key_usage &= x;
     }
 
   subpk->pubkey_usage = key_usage;
 
   p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_KEY_EXPIRE, NULL);
   if (p && buf32_to_u32 (p))
     key_expire = keytimestamp + buf32_to_u32 (p);
   else
     key_expire = 0;
 
   subpk->has_expired = key_expire >= curtime ? 0 : key_expire;
   subpk->expiredate = key_expire;
 
   /* Algo doesn't exist.  */
   if (openpgp_pk_test_algo (subpk->pubkey_algo))
     return;
 
   subpk->flags.valid = 1;
 
   /* Find the most recent 0x19 embedded signature on our self-sig. */
   if (!subpk->flags.backsig)
     {
       int seq = 0;
       size_t n;
       PKT_signature *backsig = NULL;
 
       sigdate = 0;
 
       /* We do this while() since there may be other embedded
        * signatures in the future.  We only want 0x19 here. */
 
       while ((p = enum_sig_subpkt (sig->hashed,
 				   SIGSUBPKT_SIGNATURE, &n, &seq, NULL)))
 	if (n > 3
 	    && ((p[0] == 3 && p[2] == 0x19) || (p[0] == 4 && p[1] == 0x19)))
 	  {
 	    PKT_signature *tempsig = buf_to_sig (p, n);
 	    if (tempsig)
 	      {
 		if (tempsig->timestamp > sigdate)
 		  {
 		    if (backsig)
 		      free_seckey_enc (backsig);
 
 		    backsig = tempsig;
 		    sigdate = backsig->timestamp;
 		  }
 		else
 		  free_seckey_enc (tempsig);
 	      }
 	  }
 
       seq = 0;
 
       /* It is safe to have this in the unhashed area since the 0x19
        * is located on the selfsig for convenience, not security. */
 
       while ((p = enum_sig_subpkt (sig->unhashed, SIGSUBPKT_SIGNATURE,
 				   &n, &seq, NULL)))
 	if (n > 3
 	    && ((p[0] == 3 && p[2] == 0x19) || (p[0] == 4 && p[1] == 0x19)))
 	  {
 	    PKT_signature *tempsig = buf_to_sig (p, n);
 	    if (tempsig)
 	      {
 		if (tempsig->timestamp > sigdate)
 		  {
 		    if (backsig)
 		      free_seckey_enc (backsig);
 
 		    backsig = tempsig;
 		    sigdate = backsig->timestamp;
 		  }
 		else
 		  free_seckey_enc (tempsig);
 	      }
 	  }
 
       if (backsig)
 	{
 	  /* At this point, backsig contains the most recent 0x19 sig.
 	   * Let's see if it is good. */
 
 	  /* 2==valid, 1==invalid, 0==didn't check */
 	  if (check_backsig (mainpk, subpk, backsig) == 0)
 	    subpk->flags.backsig = 2;
 	  else
 	    subpk->flags.backsig = 1;
 
 	  free_seckey_enc (backsig);
 	}
     }
 }
 
 
 /* Merge information from the self-signatures with the public key,
  * subkeys and user ids to make using them more easy.
  *
  * See documentation for merge_selfsigs_main, merge_selfsigs_subkey
  * and fixup_uidnode for exactly which fields are updated.  */
 static void
 merge_selfsigs (ctrl_t ctrl, kbnode_t keyblock)
 {
   KBNODE k;
   int revoked;
   struct revoke_info rinfo;
   PKT_public_key *main_pk;
   prefitem_t *prefs;
   unsigned int mdc_feature;
   unsigned int aead_feature;
 
   if (keyblock->pkt->pkttype != PKT_PUBLIC_KEY)
     {
       if (keyblock->pkt->pkttype == PKT_SECRET_KEY)
 	{
 	  log_error ("expected public key but found secret key "
 		     "- must stop\n");
 	  /* We better exit here because a public key is expected at
 	   * other places too.  FIXME: Figure this out earlier and
 	   * don't get to here at all */
 	  g10_exit (1);
 	}
       BUG ();
     }
 
   merge_selfsigs_main (ctrl, keyblock, &revoked, &rinfo);
 
   /* Now merge in the data from each of the subkeys.  */
   for (k = keyblock; k; k = k->next)
     {
       if (k->pkt->pkttype == PKT_PUBLIC_SUBKEY)
 	{
 	  merge_selfsigs_subkey (ctrl, keyblock, k);
 	}
     }
 
   main_pk = keyblock->pkt->pkt.public_key;
   if (revoked || main_pk->has_expired || !main_pk->flags.valid)
     {
       /* If the primary key is revoked, expired, or invalid we
        * better set the appropriate flags on that key and all
        * subkeys.  */
       for (k = keyblock; k; k = k->next)
 	{
 	  if (k->pkt->pkttype == PKT_PUBLIC_KEY
 	      || k->pkt->pkttype == PKT_PUBLIC_SUBKEY)
 	    {
 	      PKT_public_key *pk = k->pkt->pkt.public_key;
 	      if (!main_pk->flags.valid)
 		pk->flags.valid = 0;
 	      if (revoked && !pk->flags.revoked)
 		{
 		  pk->flags.revoked = revoked;
 		  memcpy (&pk->revoked, &rinfo, sizeof (rinfo));
 		}
 	      if (main_pk->has_expired)
 		pk->has_expired = main_pk->has_expired;
 	    }
 	}
       return;
     }
 
   /* Set the preference list of all keys to those of the primary real
    * user ID.  Note: we use these preferences when we don't know by
    * which user ID the key has been selected.
    * fixme: we should keep atoms of commonly used preferences or
    * use reference counting to optimize the preference lists storage.
    * FIXME: it might be better to use the intersection of
    * all preferences.
    * Do a similar thing for the MDC feature flag.  */
   prefs = NULL;
   mdc_feature = aead_feature = 0;
   for (k = keyblock; k && k->pkt->pkttype != PKT_PUBLIC_SUBKEY; k = k->next)
     {
       if (k->pkt->pkttype == PKT_USER_ID
 	  && !k->pkt->pkt.user_id->attrib_data
 	  && k->pkt->pkt.user_id->flags.primary)
 	{
 	  prefs = k->pkt->pkt.user_id->prefs;
 	  mdc_feature = k->pkt->pkt.user_id->flags.mdc;
 	  aead_feature = k->pkt->pkt.user_id->flags.aead;
 	  break;
 	}
     }
   for (k = keyblock; k; k = k->next)
     {
       if (k->pkt->pkttype == PKT_PUBLIC_KEY
 	  || k->pkt->pkttype == PKT_PUBLIC_SUBKEY)
 	{
 	  PKT_public_key *pk = k->pkt->pkt.public_key;
 	  if (pk->prefs)
 	    xfree (pk->prefs);
 	  pk->prefs = copy_prefs (prefs);
 	  pk->flags.mdc = mdc_feature;
 	  pk->flags.aead = aead_feature;
 	}
     }
 }
 
 
 
 /* See whether the key satisfies any additional requirements specified
  * in CTX.  If so, return the node of an appropriate key or subkey.
  * Otherwise, return NULL if there was no appropriate key.
  *
  * Note that we do not return a reference, i.e. the result must not be
  * freed using 'release_kbnode'.
  *
  * In case the primary key is not required, select a suitable subkey.
  * We need the primary key if PUBKEY_USAGE_CERT is set in REQ_USAGE or
  * we are in PGP6 or PGP7 mode and PUBKEY_USAGE_SIG is set in
  * REQ_USAGE.
  *
  * If any of PUBKEY_USAGE_SIG, PUBKEY_USAGE_ENC and PUBKEY_USAGE_CERT
  * are set in REQ_USAGE, we filter by the key's function.  Concretely,
  * if PUBKEY_USAGE_SIG and PUBKEY_USAGE_CERT are set, then we only
  * return a key if it is (at least) either a signing or a
  * certification key.
  *
  * If REQ_USAGE is set, then we reject any keys that are not good
  * (i.e., valid, not revoked, not expired, etc.).  This allows the
  * getkey functions to be used for plain key listings.
  *
  * Sets the matched key's user id field (pk->user_id) to the user id
  * that matched the low-level search criteria or NULL.
  *
  * If R_FLAGS is not NULL set certain flags for more detailed error
  * reporting.  Used flags are:
  *
  * - LOOKUP_ALL_SUBKEYS_EXPIRED :: All Subkeys are expired or have
  *                                 been revoked.
  * - LOOKUP_NOT_SELECTED :: No suitable key found
  *
  * This function needs to handle several different cases:
  *
  *  1. No requested usage and no primary key requested
  *     Examples for this case are that we have a keyID to be used
  *     for decrytion or verification.
  *  2. No usage but primary key requested
  *     This is the case for all functions which work on an
  *     entire keyblock, e.g. for editing or listing
  *  3. Usage and primary key requested
  *     FIXME
  *  4. Usage but no primary key requested
  *     FIXME
  *
  */
 static kbnode_t
 finish_lookup (kbnode_t keyblock, unsigned int req_usage, int want_exact,
                int want_secret, unsigned int *r_flags)
 {
   kbnode_t k;
 
   /* If WANT_EXACT is set, the key or subkey that actually matched the
      low-level search criteria.  */
   kbnode_t foundk = NULL;
   /* The user id (if any) that matched the low-level search criteria.  */
   PKT_user_id *foundu = NULL;
 
   u32 latest_date;
   kbnode_t latest_key;
   PKT_public_key *pk;
   int req_prim;
   u32 curtime = make_timestamp ();
 
   if (r_flags)
     *r_flags = 0;
 
 #define USAGE_MASK  (PUBKEY_USAGE_SIG|PUBKEY_USAGE_ENC|PUBKEY_USAGE_CERT)
   req_usage &= USAGE_MASK;
 
   /* Request the primary if we're certifying another key, and also if
    * signing data while --pgp6 or --pgp7 is on since pgp 6 and 7 do
    * not understand signatures made by a signing subkey.  PGP 8 does. */
   req_prim = ((req_usage & PUBKEY_USAGE_CERT)
               || ((PGP6 || PGP7) && (req_usage & PUBKEY_USAGE_SIG)));
 
 
   log_assert (keyblock->pkt->pkttype == PKT_PUBLIC_KEY);
 
   /* For an exact match mark the primary or subkey that matched the
    * low-level search criteria.  Use this loop also to sort our keys
    * found using an ADSK fingerprint.  */
   for (k = keyblock; k; k = k->next)
     {
       if ((k->flag & 1) && (k->pkt->pkttype == PKT_PUBLIC_KEY
                             || k->pkt->pkttype == PKT_PUBLIC_SUBKEY))
         {
           if (want_exact)
             {
               if (DBG_LOOKUP)
                 log_debug ("finish_lookup: exact search requested and found\n");
               foundk = k;
               pk = k->pkt->pkt.public_key;
               pk->flags.exact = 1;
               break;
             }
           else if ((k->pkt->pkt.public_key->pubkey_usage == PUBKEY_USAGE_RENC))
             {
               if (DBG_LOOKUP)
                 log_debug ("finish_lookup: found via ADSK - not selected\n");
               if (r_flags)
                 *r_flags |= LOOKUP_NOT_SELECTED;
               return NULL; /* Not found.  */
             }
         }
     }
 
   /* Get the user id that matched that low-level search criteria.  */
   for (k = keyblock; k; k = k->next)
     {
       if ((k->flag & 2))
 	{
 	  log_assert (k->pkt->pkttype == PKT_USER_ID);
 	  foundu = k->pkt->pkt.user_id;
 	  break;
 	}
     }
 
   if (DBG_LOOKUP)
     log_debug ("finish_lookup: checking key %08lX (%s)(req_usage=%x)\n",
 	       (ulong) keyid_from_pk (keyblock->pkt->pkt.public_key, NULL),
 	       foundk ? "one" : "all", req_usage);
 
   if (!req_usage)
     {
       latest_key = foundk ? foundk : keyblock;
       goto found;
     }
 
   latest_date = 0;
   latest_key = NULL;
   /* Set LATEST_KEY to the latest (the one with the most recent
    * timestamp) good (valid, not revoked, not expired, etc.) subkey.
    *
    * Don't bother if we are only looking for a primary key or we need
    * an exact match and the exact match is not a subkey.  */
   if (req_prim || (foundk && foundk->pkt->pkttype != PKT_PUBLIC_SUBKEY))
     ;
   else
     {
       kbnode_t nextk;
       int n_subkeys = 0;
       int n_revoked_or_expired = 0;
 
       /* Either start a loop or check just this one subkey.  */
       for (k = foundk ? foundk : keyblock; k; k = nextk)
 	{
 	  if (foundk)
             {
               /* If FOUNDK is not NULL, then only consider that exact
                  key, i.e., don't iterate.  */
               nextk = NULL;
             }
 	  else
 	    nextk = k->next;
 
 	  if (k->pkt->pkttype != PKT_PUBLIC_SUBKEY)
 	    continue;
 
 	  pk = k->pkt->pkt.public_key;
 	  if (DBG_LOOKUP)
 	    log_debug ("\tchecking subkey %08lX\n",
 		       (ulong) keyid_from_pk (pk, NULL));
 
 	  if (!pk->flags.valid)
 	    {
 	      if (DBG_LOOKUP)
 		log_debug ("\tsubkey not valid\n");
 	      continue;
 	    }
 	  if (!((pk->pubkey_usage & USAGE_MASK) & req_usage))
 	    {
 	      if (DBG_LOOKUP)
 		log_debug ("\tusage does not match: want=%x have=%x\n",
 			   req_usage, pk->pubkey_usage);
 	      continue;
 	    }
 
           n_subkeys++;
 	  if (pk->flags.revoked)
 	    {
 	      if (DBG_LOOKUP)
 		log_debug ("\tsubkey has been revoked\n");
               n_revoked_or_expired++;
 	      continue;
 	    }
 	  if (pk->has_expired)
 	    {
 	      if (DBG_LOOKUP)
 		log_debug ("\tsubkey has expired\n");
               n_revoked_or_expired++;
 	      continue;
 	    }
 	  if (pk->timestamp > curtime && !opt.ignore_valid_from)
 	    {
 	      if (DBG_LOOKUP)
 		log_debug ("\tsubkey not yet valid\n");
 	      continue;
 	    }
 
           if (want_secret && !agent_probe_secret_key (NULL, pk))
             {
               if (DBG_LOOKUP)
                 log_debug ("\tno secret key\n");
               continue;
             }
 
 	  if (DBG_LOOKUP)
 	    log_debug ("\tsubkey might be fine\n");
 	  /* In case a key has a timestamp of 0 set, we make sure
 	     that it is used.  A better change would be to compare
 	     ">=" but that might also change the selected keys and
 	     is as such a more intrusive change.  */
 	  if (pk->timestamp > latest_date || (!pk->timestamp && !latest_date))
 	    {
 	      latest_date = pk->timestamp;
 	      latest_key = k;
 	    }
 	}
       if (n_subkeys == n_revoked_or_expired && r_flags)
         *r_flags |= LOOKUP_ALL_SUBKEYS_EXPIRED;
     }
 
   /* Check if the primary key is ok (valid, not revoke, not expire,
    * matches requested usage) if:
    *
    *   - we didn't find an appropriate subkey and we're not doing an
    *     exact search,
    *
    *   - we're doing an exact match and the exact match was the
    *     primary key, or,
    *
    *   - we're just considering the primary key.  */
   if ((!latest_key && !want_exact) || foundk == keyblock || req_prim)
     {
       if (DBG_LOOKUP && !foundk && !req_prim)
 	log_debug ("\tno suitable subkeys found - trying primary\n");
       pk = keyblock->pkt->pkt.public_key;
       if (!pk->flags.valid)
 	{
 	  if (DBG_LOOKUP)
 	    log_debug ("\tprimary key not valid\n");
 	}
       else if (!((pk->pubkey_usage & USAGE_MASK) & req_usage))
 	{
 	  if (DBG_LOOKUP)
 	    log_debug ("\tprimary key usage does not match: "
 		       "want=%x have=%x\n", req_usage, pk->pubkey_usage);
 	}
       else if (pk->flags.revoked)
 	{
 	  if (DBG_LOOKUP)
 	    log_debug ("\tprimary key has been revoked\n");
 	}
       else if (pk->has_expired)
 	{
 	  if (DBG_LOOKUP)
 	    log_debug ("\tprimary key has expired\n");
 	}
       else /* Okay.  */
 	{
 	  if (DBG_LOOKUP)
 	    log_debug ("\tprimary key may be used\n");
 	  latest_key = keyblock;
 	}
     }
 
   if (!latest_key)
     {
       if (DBG_LOOKUP)
 	log_debug ("\tno suitable key found -  giving up\n");
       if (r_flags)
         *r_flags |= LOOKUP_NOT_SELECTED;
       return NULL; /* Not found.  */
     }
 
  found:
   if (DBG_LOOKUP)
     log_debug ("\tusing key %08lX\n",
 	       (ulong) keyid_from_pk (latest_key->pkt->pkt.public_key, NULL));
 
   if (latest_key)
     {
       pk = latest_key->pkt->pkt.public_key;
       free_user_id (pk->user_id);
       pk->user_id = scopy_user_id (foundu);
     }
 
   if (latest_key != keyblock && opt.verbose)
     {
       char *tempkeystr =
 	xstrdup (keystr_from_pk (latest_key->pkt->pkt.public_key));
       log_info (_("using subkey %s instead of primary key %s\n"),
 		tempkeystr, keystr_from_pk (keyblock->pkt->pkt.public_key));
       xfree (tempkeystr);
     }
 
   cache_user_id (keyblock);
 
   return latest_key ? latest_key : keyblock; /* Found.  */
 }
 
 
 /* Print a KEY_CONSIDERED status line.  */
 static void
 print_status_key_considered (kbnode_t keyblock, unsigned int flags)
 {
   char hexfpr[2*MAX_FINGERPRINT_LEN + 1];
   kbnode_t node;
   char flagbuf[20];
 
   if (!is_status_enabled ())
     return;
 
   for (node=keyblock; node; node = node->next)
     if (node->pkt->pkttype == PKT_PUBLIC_KEY
         || node->pkt->pkttype == PKT_SECRET_KEY)
       break;
   if (!node)
     {
       log_error ("%s: keyblock w/o primary key\n", __func__);
       return;
     }
 
   hexfingerprint (node->pkt->pkt.public_key, hexfpr, sizeof hexfpr);
   snprintf (flagbuf, sizeof flagbuf, " %u", flags);
   write_status_strings (STATUS_KEY_CONSIDERED, hexfpr, flagbuf, NULL);
 }
 
 
 
 /* A high-level function to lookup keys.
  *
  * This function builds on top of the low-level keydb API.  It first
  * searches the database using the description stored in CTX->ITEMS,
  * then it filters the results using CTX and, finally, if WANT_SECRET
  * is set, it ignores any keys for which no secret key is available.
  *
  * Unlike the low-level search functions, this function also merges
  * all of the self-signed data into the keys, subkeys and user id
  * packets (see the merge_selfsigs for details).
  *
  * On success the key's keyblock is stored at *RET_KEYBLOCK, and the
  * specific subkey is stored at *RET_FOUND_KEY.  Note that we do not
  * return a reference in *RET_FOUND_KEY, i.e. the result must not be
  * freed using 'release_kbnode', and it is only valid until
  * *RET_KEYBLOCK is deallocated.  Therefore, if RET_FOUND_KEY is not
  * NULL, then RET_KEYBLOCK must not be NULL.  */
 static int
 lookup (ctrl_t ctrl, getkey_ctx_t ctx, int want_secret,
         kbnode_t *ret_keyblock, kbnode_t *ret_found_key)
 {
   int rc;
   int no_suitable_key = 0;
   KBNODE keyblock = NULL;
   KBNODE found_key = NULL;
   unsigned int infoflags;
 
   log_assert (ret_found_key == NULL || ret_keyblock != NULL);
   if (ret_keyblock)
     *ret_keyblock = NULL;
 
   for (;;)
     {
       rc = keydb_search (ctx->kr_handle, ctx->items, ctx->nitems, NULL);
       if (rc)
         break;
 
       /* If we are iterating over the entire database, then we need to
        * change from KEYDB_SEARCH_MODE_FIRST, which does an implicit
        * reset, to KEYDB_SEARCH_MODE_NEXT, which gets the next record.  */
       if (ctx->nitems && ctx->items->mode == KEYDB_SEARCH_MODE_FIRST)
 	ctx->items->mode = KEYDB_SEARCH_MODE_NEXT;
 
       rc = keydb_get_keyblock (ctx->kr_handle, &keyblock);
       if (rc)
 	{
 	  log_error ("keydb_get_keyblock failed: %s\n", gpg_strerror (rc));
 	  goto skip;
 	}
 
       if (want_secret)
 	{
 	  rc = agent_probe_any_secret_key (NULL, keyblock);
 	  if (gpg_err_code(rc) == GPG_ERR_NO_SECKEY)
 	    goto skip; /* No secret key available.  */
 	  if (rc)
 	    goto found; /* Unexpected error.  */
 	}
 
       /* Warning: node flag bits 0 and 1 should be preserved by
        * merge_selfsigs.  */
       merge_selfsigs (ctrl, keyblock);
       found_key = finish_lookup (keyblock, ctx->req_usage, ctx->exact,
                                  want_secret, &infoflags);
       print_status_key_considered (keyblock, infoflags);
       if (found_key)
 	{
 	  no_suitable_key = 0;
 	  goto found;
 	}
       else
         {
           no_suitable_key = 1;
         }
 
     skip:
       /* Release resources and continue search. */
       release_kbnode (keyblock);
       keyblock = NULL;
       /* The keyblock cache ignores the current "file position".
        * Thus, if we request the next result and the cache matches
        * (and it will since it is what we just looked for), we'll get
        * the same entry back!  We can avoid this infinite loop by
        * disabling the cache.  */
       keydb_disable_caching (ctx->kr_handle);
     }
 
  found:
   if (rc && gpg_err_code (rc) != GPG_ERR_NOT_FOUND)
     log_error ("keydb_search failed: %s\n", gpg_strerror (rc));
 
   if (!rc)
     {
       if (ret_keyblock)
         {
           *ret_keyblock = keyblock; /* Return the keyblock.  */
           keyblock = NULL;
         }
     }
   else if (gpg_err_code (rc) == GPG_ERR_NOT_FOUND && no_suitable_key)
     rc = want_secret? GPG_ERR_UNUSABLE_SECKEY : GPG_ERR_UNUSABLE_PUBKEY;
   else if (gpg_err_code (rc) == GPG_ERR_NOT_FOUND)
     rc = want_secret? GPG_ERR_NO_SECKEY : GPG_ERR_NO_PUBKEY;
 
   release_kbnode (keyblock);
 
   if (ret_found_key)
     {
       if (! rc)
 	*ret_found_key = found_key;
       else
 	*ret_found_key = NULL;
     }
 
   return rc;
 }
 
 
 /* If a default key has been specified, return that key.  If a card
  * based key is also available as indicated by FPR_CARD not being
  * NULL, return that key if suitable.  */
 gpg_error_t
 get_seckey_default_or_card (ctrl_t ctrl, PKT_public_key *pk,
                             const byte *fpr_card, size_t fpr_len)
 {
   gpg_error_t err;
   strlist_t namelist = NULL;
   const char *def_secret_key;
 
   def_secret_key = parse_def_secret_key (ctrl);
 
   if (def_secret_key)
     add_to_strlist (&namelist, def_secret_key);
   else if (fpr_card)
     {
       err = get_pubkey_byfprint (ctrl, pk, NULL, fpr_card, fpr_len);
       if (gpg_err_code (err) == GPG_ERR_NO_PUBKEY)
         {
           if (opt.debug)
             log_debug ("using LDAP to find public key for current card\n");
           err = keyserver_import_fprint (ctrl, fpr_card, fpr_len,
                                          opt.keyserver,
                                          KEYSERVER_IMPORT_FLAG_LDAP);
           if (!err)
             err = get_pubkey_byfprint (ctrl, pk, NULL, fpr_card, fpr_len);
           else if (gpg_err_code (err) == GPG_ERR_NO_DATA
                    || gpg_err_code (err) == GPG_ERR_NO_KEYSERVER)
             {
               /* Dirmngr returns NO DATA is the selected keyserver
                * does not have the requested key.  It returns NO
                * KEYSERVER if no LDAP keyservers are configured.  */
               err = gpg_error (GPG_ERR_NO_PUBKEY);
             }
         }
 
       /* The key on card can be not suitable for requested usage.  */
       if (gpg_err_code (err) == GPG_ERR_UNUSABLE_PUBKEY)
         fpr_card = NULL;        /* Fallthrough as no card.  */
       else
         return err;  /* Success or other error.  */
     }
 
   if (!fpr_card || (def_secret_key && *def_secret_key
                     && def_secret_key[strlen (def_secret_key)-1] == '!'))
     {
       err = key_byname (ctrl, NULL, namelist, pk, 1, 0, NULL, NULL);
     }
   else
     { /* Default key is specified and card key is also available.  */
       kbnode_t k, keyblock = NULL;
 
       err = key_byname (ctrl, NULL, namelist, pk, 1, 0, &keyblock, NULL);
       if (err)
         goto leave;
       for (k = keyblock; k; k = k->next)
         {
           PKT_public_key *pk_candidate;
           char fpr[MAX_FINGERPRINT_LEN];
 
           if (k->pkt->pkttype != PKT_PUBLIC_KEY
               &&k->pkt->pkttype != PKT_PUBLIC_SUBKEY)
             continue;
 
           pk_candidate = k->pkt->pkt.public_key;
           if (!pk_candidate->flags.valid)
             continue;
           if (!((pk_candidate->pubkey_usage & USAGE_MASK) & pk->req_usage))
             continue;
           fingerprint_from_pk (pk_candidate, fpr, NULL);
           if (!memcmp (fpr_card, fpr, fpr_len))
             {
               release_public_key_parts (pk);
               copy_public_key (pk, pk_candidate);
               break;
             }
         }
       release_kbnode (keyblock);
     }
 
  leave:
   free_strlist (namelist);
   return err;
 }
 
 
 
 /*********************************************
  ***********  User ID printing helpers *******
  *********************************************/
 
 /* Return a string with a printable representation of the user_id.
  * this string must be freed by xfree.  If R_NOUID is not NULL it is
  * set to true if a user id was not found; otherwise to false.  */
 static char *
 get_user_id_string (ctrl_t ctrl, u32 * keyid, int mode, size_t *r_len,
                     int *r_nouid)
 {
   user_id_db_t r;
   keyid_list_t a;
   int pass = 0;
   char *p;
 
   if (r_nouid)
     *r_nouid = 0;
 
   /* Try it two times; second pass reads from the database.  */
   do
     {
       for (r = user_id_db; r; r = r->next)
 	{
 	  for (a = r->keyids; a; a = a->next)
 	    {
 	      if (a->keyid[0] == keyid[0] && a->keyid[1] == keyid[1])
 		{
                   if (mode == 2)
                     {
                       /* An empty string as user id is possible.  Make
                          sure that the malloc allocates one byte and
                          does not bail out.  */
                       p = xmalloc (r->len? r->len : 1);
                       memcpy (p, r->name, r->len);
                       if (r_len)
                         *r_len = r->len;
                     }
                   else
                     {
                       if (mode)
                         p = xasprintf ("%08lX%08lX %.*s",
                                        (ulong) keyid[0], (ulong) keyid[1],
                                        r->len, r->name);
                       else
                         p = xasprintf ("%s %.*s", keystr (keyid),
                                        r->len, r->name);
                       if (r_len)
                         *r_len = strlen (p);
                     }
 
                   return p;
 		}
 	    }
 	}
     }
   while (++pass < 2 && !get_pubkey (ctrl, NULL, keyid));
 
   if (mode == 2)
     p = xstrdup (user_id_not_found_utf8 ());
   else if (mode)
     p = xasprintf ("%08lX%08lX [?]", (ulong) keyid[0], (ulong) keyid[1]);
   else
     p = xasprintf ("%s [?]", keystr (keyid));
 
   if (r_nouid)
     *r_nouid = 1;
   if (r_len)
     *r_len = strlen (p);
   return p;
 }
 
 
 char *
 get_user_id_string_native (ctrl_t ctrl, u32 * keyid)
 {
   char *p = get_user_id_string (ctrl, keyid, 0, NULL, NULL);
   char *p2 = utf8_to_native (p, strlen (p), 0);
   xfree (p);
   return p2;
 }
 
 
 char *
 get_long_user_id_string (ctrl_t ctrl, u32 * keyid)
 {
   return get_user_id_string (ctrl, keyid, 1, NULL, NULL);
 }
 
 
 /* Please try to use get_user_byfpr instead of this one.  */
 char *
 get_user_id (ctrl_t ctrl, u32 *keyid, size_t *rn, int *r_nouid)
 {
   return get_user_id_string (ctrl, keyid, 2, rn, r_nouid);
 }
 
 
 /* Please try to use get_user_id_byfpr_native instead of this one.  */
 char *
 get_user_id_native (ctrl_t ctrl, u32 *keyid)
 {
   size_t rn;
   char *p = get_user_id (ctrl, keyid, &rn, NULL);
   char *p2 = utf8_to_native (p, rn, 0);
   xfree (p);
   return p2;
 }
 
 
 /* Return the user id for a key designated by its fingerprint, FPR,
    which must be MAX_FINGERPRINT_LEN bytes in size.  Note: the
    returned string, which must be freed using xfree, may not be NUL
    terminated.  To determine the length of the string, you must use
    *RN.  */
 char *
 get_user_id_byfpr (ctrl_t ctrl, const byte *fpr, size_t *rn)
 {
   user_id_db_t r;
   char *p;
   int pass = 0;
 
   /* Try it two times; second pass reads from the database.  */
   do
     {
       for (r = user_id_db; r; r = r->next)
 	{
 	  keyid_list_t a;
 	  for (a = r->keyids; a; a = a->next)
 	    {
 	      if (!memcmp (a->fpr, fpr, MAX_FINGERPRINT_LEN))
 		{
                   /* An empty string as user id is possible.  Make
                      sure that the malloc allocates one byte and does
                      not bail out.  */
 		  p = xmalloc (r->len? r->len : 1);
 		  memcpy (p, r->name, r->len);
 		  *rn = r->len;
 		  return p;
 		}
 	    }
 	}
     }
   while (++pass < 2
 	 && !get_pubkey_byfprint (ctrl, NULL, NULL, fpr, MAX_FINGERPRINT_LEN));
   p = xstrdup (user_id_not_found_utf8 ());
   *rn = strlen (p);
   return p;
 }
 
 /* Like get_user_id_byfpr, but convert the string to the native
    encoding.  The returned string needs to be freed.  Unlike
    get_user_id_byfpr, the returned string is NUL terminated.  */
 char *
 get_user_id_byfpr_native (ctrl_t ctrl, const byte *fpr)
 {
   size_t rn;
   char *p = get_user_id_byfpr (ctrl, fpr, &rn);
   char *p2 = utf8_to_native (p, rn, 0);
   xfree (p);
   return p2;
 }
 
 
 /* Return the database handle used by this context.  The context still
    owns the handle.  */
 KEYDB_HANDLE
 get_ctx_handle (GETKEY_CTX ctx)
 {
   return ctx->kr_handle;
 }
 
 static void
 free_akl (struct akl *akl)
 {
   if (! akl)
     return;
 
   if (akl->spec)
     free_keyserver_spec (akl->spec);
 
   xfree (akl);
 }
 
 void
 release_akl (void)
 {
   while (opt.auto_key_locate)
     {
       struct akl *akl2 = opt.auto_key_locate;
       opt.auto_key_locate = opt.auto_key_locate->next;
       free_akl (akl2);
     }
 }
 
 
 /* Returns true if the AKL is empty or has only the local method
  * active.  */
 int
 akl_empty_or_only_local (void)
 {
   struct akl *akl;
   int any = 0;
 
   for (akl = opt.auto_key_locate; akl; akl = akl->next)
     if (akl->type != AKL_NODEFAULT && akl->type != AKL_LOCAL)
       {
         any = 1;
         break;
       }
 
   return !any;
 }
 
 
 /* Returns false on error. */
 int
 parse_auto_key_locate (const char *options_arg)
 {
   char *tok;
   char *options, *options_buf;
 
   options = options_buf = xstrdup (options_arg);
   while ((tok = optsep (&options)))
     {
       struct akl *akl, *check, *last = NULL;
       int dupe = 0;
 
       if (tok[0] == '\0')
 	continue;
 
       akl = xmalloc_clear (sizeof (*akl));
 
       if (ascii_strcasecmp (tok, "clear") == 0)
 	{
           xfree (akl);
           free_akl (opt.auto_key_locate);
           opt.auto_key_locate = NULL;
           continue;
         }
       else if (ascii_strcasecmp (tok, "nodefault") == 0)
 	akl->type = AKL_NODEFAULT;
       else if (ascii_strcasecmp (tok, "local") == 0)
 	akl->type = AKL_LOCAL;
       else if (ascii_strcasecmp (tok, "ldap") == 0)
 	akl->type = AKL_LDAP;
       else if (ascii_strcasecmp (tok, "keyserver") == 0)
 	akl->type = AKL_KEYSERVER;
       else if (ascii_strcasecmp (tok, "cert") == 0)
 	akl->type = AKL_CERT;
       else if (ascii_strcasecmp (tok, "pka") == 0)
 	akl->type = AKL_PKA;
       else if (ascii_strcasecmp (tok, "dane") == 0)
 	akl->type = AKL_DANE;
       else if (ascii_strcasecmp (tok, "wkd") == 0)
 	akl->type = AKL_WKD;
       else if (ascii_strcasecmp (tok, "ntds") == 0)
 	akl->type = AKL_NTDS;
       else if ((akl->spec = parse_keyserver_uri (tok, 1)))
 	akl->type = AKL_SPEC;
       else
 	{
 	  free_akl (akl);
           xfree (options_buf);
 	  return 0;
 	}
 
       /* We must maintain the order the user gave us */
       for (check = opt.auto_key_locate; check;
 	   last = check, check = check->next)
 	{
 	  /* Check for duplicates */
 	  if (check->type == akl->type
 	      && (akl->type != AKL_SPEC
 		  || (akl->type == AKL_SPEC
 		      && strcmp (check->spec->uri, akl->spec->uri) == 0)))
 	    {
 	      dupe = 1;
 	      free_akl (akl);
 	      break;
 	    }
 	}
 
       if (!dupe)
 	{
 	  if (last)
 	    last->next = akl;
 	  else
 	    opt.auto_key_locate = akl;
 	}
     }
 
   xfree (options_buf);
   return 1;
 }
 
 
 
 /* The list of key origins. */
 static struct {
   const char *name;
   int origin;
 } key_origin_list[] =
   {
     { "self",    KEYORG_SELF    },
     { "file",    KEYORG_FILE    },
     { "url",     KEYORG_URL     },
     { "wkd",     KEYORG_WKD     },
     { "dane",    KEYORG_DANE    },
     { "ks-pref", KEYORG_KS_PREF },
     { "ks",      KEYORG_KS      },
     { "unknown", KEYORG_UNKNOWN }
   };
 
 /* Parse the argument for --key-origin.  Return false on error. */
 int
 parse_key_origin (char *string)
 {
   int i;
   char *comma;
 
   comma = strchr (string, ',');
   if (comma)
     *comma = 0;
 
   if (!ascii_strcasecmp (string, "help"))
     {
       log_info (_("valid values for option '%s':\n"), "--key-origin");
       for (i=0; i < DIM (key_origin_list); i++)
         log_info ("  %s\n", key_origin_list[i].name);
       g10_exit (1);
     }
 
   for (i=0; i < DIM (key_origin_list); i++)
     if (!ascii_strcasecmp (string, key_origin_list[i].name))
       {
         opt.key_origin = key_origin_list[i].origin;
         xfree (opt.key_origin_url);
         opt.key_origin_url = NULL;
         if (comma && comma[1])
           {
             opt.key_origin_url = xstrdup (comma+1);
             trim_spaces (opt.key_origin_url);
           }
 
         return 1;
       }
 
   if (comma)
     *comma = ',';
   return 0;
 }
 
 /* Return a string or "?" for the key ORIGIN.  */
 const char *
 key_origin_string (int origin)
 {
   int i;
 
   for (i=0; i < DIM (key_origin_list); i++)
     if (key_origin_list[i].origin == origin)
       return key_origin_list[i].name;
   return "?";
 }
 
 
 
 /* Returns true if a secret key is available for the public key with
    key id KEYID; returns false if not.  This function ignores legacy
    keys.  Note: this is just a fast check and does not tell us whether
    the secret key is valid; this check merely indicates whether there
    is some secret key with the specified key id.  */
 int
 have_secret_key_with_kid (u32 *keyid)
 {
   gpg_error_t err;
   KEYDB_HANDLE kdbhd;
   KEYDB_SEARCH_DESC desc;
   kbnode_t keyblock;
   kbnode_t node;
   int result = 0;
 
   kdbhd = keydb_new ();
   if (!kdbhd)
     return 0;
   memset (&desc, 0, sizeof desc);
   desc.mode = KEYDB_SEARCH_MODE_LONG_KID;
   desc.u.kid[0] = keyid[0];
   desc.u.kid[1] = keyid[1];
   while (!result)
     {
       err = keydb_search (kdbhd, &desc, 1, NULL);
       if (err)
         break;
 
       err = keydb_get_keyblock (kdbhd, &keyblock);
       if (err)
         {
           log_error (_("error reading keyblock: %s\n"), gpg_strerror (err));
           break;
         }
 
       for (node = keyblock; node; node = node->next)
 	{
           /* Bit 0 of the flags is set if the search found the key
              using that key or subkey.  Note: a search will only ever
              match a single key or subkey.  */
 	  if ((node->flag & 1))
             {
               log_assert (node->pkt->pkttype == PKT_PUBLIC_KEY
                           || node->pkt->pkttype == PKT_PUBLIC_SUBKEY);
 
               if (agent_probe_secret_key (NULL, node->pkt->pkt.public_key))
 		result = 1; /* Secret key available.  */
 	      else
 		result = 0;
 
 	      break;
 	    }
 	}
       release_kbnode (keyblock);
     }
 
   keydb_release (kdbhd);
   return result;
 }
diff --git a/g10/packet.h b/g10/packet.h
index 409d7d419..b0a51d1b5 100644
--- a/g10/packet.h
+++ b/g10/packet.h
@@ -1,946 +1,951 @@
 /* packet.h - OpenPGP packet definitions
  * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
  *               2007 Free Software Foundation, Inc.
  * Copyright (C) 2015 g10 Code GmbH
  *
  * This file is part of GnuPG.
  *
  * GnuPG is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 3 of the License, or
  * (at your option) any later version.
  *
  * GnuPG is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see <https://www.gnu.org/licenses/>.
  */
 
 #ifndef G10_PACKET_H
 #define G10_PACKET_H
 
 #include "../common/types.h"
 #include "../common/iobuf.h"
 #include "../common/strlist.h"
 #include "dek.h"
 #include "filter.h"
 #include "../common/openpgpdefs.h"
 #include "../common/userids.h"
 #include "../common/util.h"
 
 #define DEBUG_PARSE_PACKET 1
 
 /* Maximum length of packets to avoid excessive memory allocation.  */
 #define MAX_KEY_PACKET_LENGTH     (256 * 1024)
 #define MAX_UID_PACKET_LENGTH     (  2 * 1024)
 #define MAX_COMMENT_PACKET_LENGTH ( 64 * 1024)
 #define MAX_ATTR_PACKET_LENGTH    ( 16 * 1024*1024)
 
 /* Constants to allocate static MPI arrays.  */
 #define PUBKEY_MAX_NPKEY  OPENPGP_MAX_NPKEY
 #define PUBKEY_MAX_NSKEY  OPENPGP_MAX_NSKEY
 #define PUBKEY_MAX_NSIG   OPENPGP_MAX_NSIG
 #define PUBKEY_MAX_NENC   OPENPGP_MAX_NENC
 
 /* Usage flags */
 #define PUBKEY_USAGE_SIG     GCRY_PK_USAGE_SIGN  /* Good for signatures. */
 #define PUBKEY_USAGE_ENC     GCRY_PK_USAGE_ENCR  /* Good for encryption. */
 #define PUBKEY_USAGE_CERT    GCRY_PK_USAGE_CERT  /* Also good to certify keys.*/
 #define PUBKEY_USAGE_AUTH    GCRY_PK_USAGE_AUTH  /* Good for authentication. */
 #define PUBKEY_USAGE_UNKNOWN GCRY_PK_USAGE_UNKN  /* Unknown usage flag. */
 #define PUBKEY_USAGE_NONE    256                 /* No usage given. */
 #if  (GCRY_PK_USAGE_SIGN | GCRY_PK_USAGE_ENCR | GCRY_PK_USAGE_CERT \
       | GCRY_PK_USAGE_AUTH | GCRY_PK_USAGE_UNKN) >= 256
 # error Please choose another value for PUBKEY_USAGE_NONE
 #endif
 #define PUBKEY_USAGE_GROUP   512                 /* Group flag.  */
 #define PUBKEY_USAGE_RENC    1024                /* Restricted encryption.  */
 #define PUBKEY_USAGE_TIME    2048                /* Timestamp use.  */
 
+/* The usage bits which can be derived from the algo.  */
+#define PUBKEY_USAGE_BASIC_MASK  (PUBKEY_USAGE_SIG|PUBKEY_USAGE_ENC\
+                                  |PUBKEY_USAGE_CERT|PUBKEY_USAGE_AUTH)
+
+
 /* Helper macros.  */
 #define is_RSA(a)     ((a)==PUBKEY_ALGO_RSA || (a)==PUBKEY_ALGO_RSA_E \
 		       || (a)==PUBKEY_ALGO_RSA_S )
 #define is_ELGAMAL(a) ((a)==PUBKEY_ALGO_ELGAMAL_E)
 #define is_DSA(a)     ((a)==PUBKEY_ALGO_DSA)
 
 /* A pointer to the packet object.  */
 typedef struct packet_struct PACKET;
 
 /* PKT_GPG_CONTROL types */
 typedef enum {
     CTRLPKT_CLEARSIGN_START = 1,
     CTRLPKT_PIPEMODE = 2,
     CTRLPKT_PLAINTEXT_MARK =3
 } ctrlpkttype_t;
 
 typedef enum {
     PREFTYPE_NONE = 0,
     PREFTYPE_SYM = 1,
     PREFTYPE_HASH = 2,
     PREFTYPE_ZIP = 3,
     PREFTYPE_AEAD = 4
 } preftype_t;
 
 typedef struct {
     byte type;
     byte value;
 } prefitem_t;
 
 /* A string-to-key specifier as defined in RFC 4880, Section 3.7.  */
 typedef struct
 {
   int  mode;      /* Must be an integer due to the GNU modes 1001 et al.  */
   byte hash_algo;
   byte salt[8];
   /* The *coded* (i.e., the serialized version) iteration count.  */
   u32  count;
 } STRING2KEY;
 
 /* A symmetric-key encrypted session key packet as defined in RFC
    4880, Section 5.3.  All fields are serialized.  */
 typedef struct {
   /* RFC 4880: this must be 4.  */
   byte version;
   /* The cipher algorithm used to encrypt the session key.  (This may
      be different from the algorithm that is used to encrypt the SED
      packet.)  */
   byte cipher_algo;
   /* The AEAD algorithm or 0 for CFB encryption.  */
   byte aead_algo;
   /* The string-to-key specifier.  */
   STRING2KEY s2k;
   /* The length of SESKEY in bytes or 0 if this packet does not
      encrypt a session key.  (In the latter case, the results of the
      S2K function on the password is the session key. See RFC 4880,
      Section 5.3.)  */
   byte seskeylen;
   /* The session key as encrypted by the S2K specifier.  For AEAD this
    * includes the nonce and the authentication tag.  */
   byte seskey[1];
 } PKT_symkey_enc;
 
 /* A public-key encrypted session key packet as defined in RFC 4880,
    Section 5.1.  All fields are serialized.  */
 typedef struct {
   /* The 64-bit keyid.  */
   u32     keyid[2];
   /* The packet's version.  Currently, only version 3 is defined.  */
   byte    version;
   /* The algorithm used for the public key encryption scheme.  */
   byte    pubkey_algo;
   /* Whether to hide the key id.  This value is not directly
      serialized.  */
   byte    throw_keyid;
   /* The session key.  */
   gcry_mpi_t     data[PUBKEY_MAX_NENC];
 } PKT_pubkey_enc;
 
 
 /* A one-pass signature packet as defined in RFC 4880, Section
    5.4.  All fields are serialized.  */
 typedef struct {
     u32     keyid[2];	    /* The 64-bit keyid */
     /* The signature's classification (RFC 4880, Section 5.2.1).  */
     byte    sig_class;
     byte    digest_algo;    /* algorithm used for digest */
     byte    pubkey_algo;    /* algorithm used for public key scheme */
     /* A message can be signed by multiple keys.  In this case, there
        are n one-pass signature packets before the message to sign and
        n signatures packets after the message.  It is conceivable that
        someone wants to not only sign the message, but all of the
        signatures.  Now we need to distinguish between signing the
        message and signing the message plus the surrounding
        signatures.  This is the point of this flag.  If set, it means:
        I sign all of the data starting at the next packet.  */
     byte    last;
 } PKT_onepass_sig;
 
 
 /* A v4 OpenPGP signature has a hashed and unhashed area containing
    co-called signature subpackets (RFC 4880, Section 5.2.3).  These
    areas are described by this data structure.  Use enum_sig_subpkt to
    parse this area.  */
 typedef struct {
     size_t size;  /* allocated */
     size_t len;   /* used (serialized) */
     byte data[1]; /* the serialized subpackes (serialized) */
 } subpktarea_t;
 
 /* The in-memory representation of a designated revoker signature
    subpacket (RFC 4880, Section 5.2.3.15).  */
 struct revocation_key {
   /* A bit field.  0x80 must be set.  0x40 means this information is
      sensitive (and should not be uploaded to a keyserver by
      default).  */
   byte class;
   /* The public-key algorithm ID.  */
   byte algid;
   /* The fingerprint of the authorized key.  */
   byte fpr[MAX_FINGERPRINT_LEN];
 };
 
 
 /* Object to keep information about a PKA DNS record. */
 typedef struct
 {
   int valid;    /* An actual PKA record exists for EMAIL. */
   int checked;  /* Set to true if the FPR has been checked against the
                    actual key. */
   char *uri;    /* Malloced string with the URI. NULL if the URI is
                    not available.*/
   unsigned char fpr[20]; /* The fingerprint as stored in the PKA RR. */
   char email[1];/* The email address from the notation data. */
 } pka_info_t;
 
 
 /* A signature packet (RFC 4880, Section 5.2).  Only a subset of these
    fields are directly serialized (these are marked as such); the rest
    are read from the subpackets, which are not synthesized when
    serializing this data structure (i.e., when using build_packet()).
    Instead, the subpackets must be created by hand.  */
 typedef struct
 {
   struct
   {
     unsigned checked:1;         /* Signature has been checked. */
     unsigned valid:1;           /* Signature is good (if checked is set). */
     unsigned chosen_selfsig:1;  /* A selfsig that is the chosen one. */
     unsigned unknown_critical:1;
     unsigned exportable:1;
     unsigned revocable:1;
     unsigned policy_url:1;  /* At least one policy URL is present */
     unsigned notation:1;    /* At least one notation is present */
     unsigned pref_ks:1;     /* At least one preferred keyserver is present */
     unsigned key_block:1;   /* A key block subpacket is present.  */
     unsigned expired:1;
     unsigned pka_tried:1;   /* Set if we tried to retrieve the PKA record. */
   } flags;
   /* The key that allegedly generated this signature.  (Directly
      serialized in v3 sigs; for v4 sigs, this must be explicitly added
      as an issuer subpacket (5.2.3.5.)  */
   u32     keyid[2];
   /* When the signature was made (seconds since the Epoch).  (Directly
      serialized in v3 sigs; for v4 sigs, this must be explicitly added
      as a signature creation time subpacket (5.2.3.4).)  */
   u32     timestamp;
   u32     expiredate;     /* Expires at this date or 0 if not at all. */
   /* The serialization format used / to use.  If 0, then defaults to
      version 3.  (Serialized.)  */
   byte    version;
   /* The signature type. (See RFC 4880, Section 5.2.1.)  */
   byte    sig_class;
   /* Algorithm used for public key scheme (e.g., PUBKEY_ALGO_RSA).
      (Serialized.)  */
   byte    pubkey_algo;
   /* Algorithm used for digest (e.g., DIGEST_ALGO_SHA1).
      (Serialized.)  */
   byte    digest_algo;
   byte    trust_depth;
   byte    trust_value;
   const byte *trust_regexp;
   struct revocation_key *revkey;
   int numrevkeys;
   int help_counter;          /* Used internally bu some fucntions.  */
   pka_info_t *pka_info;      /* Malloced PKA data or NULL if not
                                 available.  See also flags.pka_tried. */
   char *signers_uid;         /* Malloced value of the SIGNERS_UID
                               * subpacket or NULL.  This string has
                               * already been sanitized.  */
   subpktarea_t *hashed;      /* All subpackets with hashed data (v4 only). */
   subpktarea_t *unhashed;    /* Ditto for unhashed data. */
   /* First 2 bytes of the digest.  (Serialized.  Note: this is not
      automatically filled in when serializing a signature!)  */
   byte digest_start[2];
   /* The signature.  (Serialized.)  */
   gcry_mpi_t  data[PUBKEY_MAX_NSIG];
   /* The message digest and its length (in bytes).  Note the maximum
      digest length is 512 bits (64 bytes).  If DIGEST_LEN is 0, then
      the digest's value has not been saved here.  */
   byte digest[512 / 8];
   int digest_len;
 } PKT_signature;
 
 #define ATTRIB_IMAGE 1
 
 /* This is the cooked form of attributes.  */
 struct user_attribute {
   byte type;
   const byte *data;
   u32 len;
 };
 
 
 /* A user id (RFC 4880, Section 5.11) or a user attribute packet (RFC
    4880, Section 5.12).  Only a subset of these fields are directly
    serialized (these are marked as such); the rest are read from the
    self-signatures in merge_keys_and_selfsig()).  */
 typedef struct
 {
   int ref;              /* reference counter */
   /* The length of NAME.  */
   int len;
   struct user_attribute *attribs;
   int numattribs;
   /* If this is not NULL, the packet is a user attribute rather than a
      user id (See RFC 4880 5.12).  (Serialized.)  */
   byte *attrib_data;
   /* The length of ATTRIB_DATA.  */
   unsigned long attrib_len;
   byte *namehash;
   u16 help_key_usage;
   u32 help_key_expire;
   int help_full_count;
   int help_marginal_count;
   u32 expiredate;       /* expires at this date or 0 if not at all */
   prefitem_t *prefs;    /* list of preferences (may be NULL)*/
   u32 created;          /* according to the self-signature */
   u32 keyupdate;        /* From the ring trust packet.  */
   char *updateurl;      /* NULL or the URL of the last update origin.  */
   byte keyorg;          /* From the ring trust packet.  */
   byte selfsigversion;
   struct
   {
     unsigned int mdc:1;
     unsigned int aead:1;
     unsigned int ks_modify:1;
     unsigned int compacted:1;
     unsigned int primary:2; /* 2 if set via the primary flag, 1 if calculated */
     unsigned int revoked:1;
     unsigned int expired:1;
   } flags;
 
   char *mbox;   /* NULL or the result of mailbox_from_userid.  */
 
   /* The text contained in the user id packet, which is normally the
    * name and email address of the key holder (See RFC 4880 5.11).
    * (Serialized.). For convenience an extra Nul is always appended.  */
   char name[1];
 } PKT_user_id;
 
 
 
 struct revoke_info
 {
   /* revoked at this date */
   u32 date;
   /* the keyid of the revoking key (selfsig or designated revoker) */
   u32 keyid[2];
   /* the algo of the revoking key */
   byte algo;
 };
 
 
 /* Information pertaining to secret keys. */
 struct seckey_info
 {
   int is_protected:1;	/* The secret info is protected and must */
 			/* be decrypted before use, the protected */
 			/* MPIs are simply (void*) pointers to memory */
 			/* and should never be passed to a mpi_xxx() */
   int sha1chk:1;        /* SHA1 is used instead of a 16 bit checksum */
   u16 csum;		/* Checksum for old protection modes.  */
   byte algo;            /* Cipher used to protect the secret information. */
   STRING2KEY s2k;       /* S2K parameter.  */
   byte ivlen;           /* Used length of the IV.  */
   byte iv[16];          /* Initialization vector for CFB mode.  */
 };
 
 
 /****************
  * The in-memory representation of a public key (RFC 4880, Section
  * 5.5).  Note: this structure contains significantly more information
  * than is contained in an OpenPGP public key packet.  This
  * information is derived from the self-signed signatures (by
  * merge_keys_and_selfsig()) and is ignored when serializing the
  * packet.  The fields that are actually written out when serializing
  * this packet are marked as accordingly.
  *
  * We assume that secret keys have the same number of parameters as
  * the public key and that the public parameters are the first items
  * in the PKEY array.  Thus NPKEY is always less than NSKEY and it is
  * possible to compare the secret and public keys by comparing the
  * first NPKEY elements of the PKEY array.  Note that since GnuPG 2.1
  * we don't use secret keys anymore directly because they are managed
  * by gpg-agent.  However for parsing OpenPGP key files we need a way
  * to temporary store those secret keys.  We do this by putting them
  * into the public key structure and extending the PKEY field to NSKEY
  * elements; the extra secret key information are stored in the
  * SECKEY_INFO field.
  */
 typedef struct
 {
   /* When the key was created.  (Serialized.)  */
   u32     timestamp;
   u32     expiredate;     /* expires at this date or 0 if not at all */
   u32     max_expiredate; /* must not expire past this date */
   struct revoke_info revoked;
   /* An OpenPGP packet consists of a header and a body.  This is the
      size of the header.  If this is 0, an appropriate size is
      automatically chosen based on the size of the body.
      (Serialized.)  */
   byte    hdrbytes;
   /* The serialization format.  If 0, the default version (4) is used
      when serializing.  (Serialized.)  */
   byte    version;
   byte    selfsigversion; /* highest version of all of the self-sigs */
   /* The public key algorithm.  (Serialized.)  */
   byte    pubkey_algo;
   u16     pubkey_usage;   /* carries the usage info.            */
   byte    req_usage;      /* hack to pass a request to getkey() */
   u32     has_expired;    /* set to the expiration date if expired */
   /* keyid of the primary key.  Never access this value directly.
      Instead, use pk_main_keyid().  */
   u32     main_keyid[2];
   /* keyid of this key.  Never access this value directly!  Instead,
      use pk_keyid().  */
   u32     keyid[2];
   prefitem_t *prefs;      /* list of preferences (may be NULL) */
   struct
   {
     unsigned int mdc:1;           /* MDC feature set.  */
     unsigned int aead:1;          /* AEAD feature set.  */
     unsigned int disabled_valid:1;/* The next flag is valid.  */
     unsigned int disabled:1;      /* The key has been disabled.  */
     unsigned int primary:1;       /* This is a primary key.  */
     unsigned int revoked:2;       /* Key has been revoked.
                                      1 = revoked by the owner
                                      2 = revoked by designated revoker.  */
     unsigned int maybe_revoked:1; /* A designated revocation is
                                      present, but without the key to
                                      check it.  */
     unsigned int valid:1;         /* Key (especially subkey) is valid.  */
     unsigned int dont_cache:1;    /* Do not cache this key.  */
     unsigned int backsig:2;       /* 0=none, 1=bad, 2=good.  */
     unsigned int serialno_valid:1;/* SERIALNO below is valid.  */
     unsigned int exact:1;         /* Found via exact (!) search.  */
   } flags;
   PKT_user_id *user_id;   /* If != NULL: found by that uid. */
   struct revocation_key *revkey;
   int     numrevkeys;
   u32     trust_timestamp;
   byte    trust_depth;
   byte    trust_value;
   byte    keyorg;         /* From the ring trust packet.  */
   u32     keyupdate;      /* From the ring trust packet.  */
   char    *updateurl;     /* NULL or the URL of the last update origin.  */
   const byte *trust_regexp;
   char    *serialno;      /* Malloced hex string or NULL if it is
                              likely not on a card.  See also
                              flags.serialno_valid.  */
   /* If not NULL this malloced structure describes a secret key.
      (Serialized.)  */
   struct seckey_info *seckey_info;
   /* The public key.  Contains pubkey_get_npkey (pubkey_algo) +
      pubkey_get_nskey (pubkey_algo) MPIs.  (If pubkey_get_npkey
      returns 0, then the algorithm is not understood and the PKEY
      contains a single opaque MPI.)  (Serialized.)  */
   gcry_mpi_t  pkey[PUBKEY_MAX_NSKEY]; /* Right, NSKEY elements.  */
 } PKT_public_key;
 
 /* Evaluates as true if the pk is disabled, and false if it isn't.  If
    there is no disable value cached, fill one in. */
 #define pk_is_disabled(a)                                       \
   (((a)->flags.disabled_valid)?                                 \
    ((a)->flags.disabled):(cache_disabled_value(ctrl,(a))))
 
 
 typedef struct {
     int  len;		  /* length of data */
     char data[1];
 } PKT_comment;
 
 /* A compression packet (RFC 4880, Section 5.6).  */
 typedef struct {
   /* Not used.  */
   u32 len;
   /* Whether the serialized version of the packet used / should use
      the new format.  */
   byte  new_ctb;
   /* The compression algorithm.  */
   byte  algorithm;
   /* An iobuf holding the data to be decompressed.  (This is not used
      for compression!)  */
   iobuf_t buf;
 } PKT_compressed;
 
 /* A symmetrically encrypted data packet (RFC 4880, Section 5.7) or a
    symmetrically encrypted integrity protected data packet (Section
    5.13) */
 typedef struct {
   /* Remaining length of encrypted data. */
   u32  len;
   /* When encrypting in CFB mode, the first block size bytes of data
    * are random data and the following 2 bytes are copies of the last
    * two bytes of the random data (RFC 4880, Section 5.7).  This
    * provides a simple check that the key is correct.  EXTRALEN is the
    * size of this extra data or, in AEAD mode, the length of the
    * headers and the tags.  This is used by build_packet when writing
    * out the packet's header. */
   int  extralen;
   /* Whether the serialized version of the packet used / should use
      the new format.  */
   byte new_ctb;
   /* Whether the packet has an indeterminate length (old format) or
      was encoded using partial body length headers (new format).
      Note: this is ignored when encrypting.  */
   byte is_partial;
   /* If 0, MDC is disabled.  Otherwise, the MDC method that was used
      (currently, only DIGEST_ALGO_SHA1 is supported).  */
   byte mdc_method;
   /* If 0, AEAD is not used.  Otherwise, the used AEAD algorithm.
    * MDC_METHOD (above) shall be zero if AEAD is used.  */
   byte aead_algo;
   /* The cipher algo for/from the AEAD packet.  0 for other encryption
    * packets. */
   byte cipher_algo;
   /* The chunk byte from the AEAD packet.  */
   byte chunkbyte;
 
   /* An iobuf holding the data to be decrypted.  (This is not used for
      encryption!)  */
   iobuf_t buf;
 } PKT_encrypted;
 
 typedef struct {
     byte hash[20];
 } PKT_mdc;
 
 
 /* Subtypes for the ring trust packet.  */
 #define RING_TRUST_SIG 0  /* The classical signature cache.  */
 #define RING_TRUST_KEY 1  /* A KEYORG on a primary key.      */
 #define RING_TRUST_UID 2  /* A KEYORG on a user id.          */
 
 /* The local only ring trust packet which OpenPGP declares as
  * implementation defined.  GnuPG uses this to cache signature
  * verification status and since 2.1.18 also to convey information
  * about the origin of a key.  Note that this packet is not part
  * struct packet_struct because we use it only local in the packet
  * parser and builder. */
 typedef struct {
   unsigned int trustval;
   unsigned int sigcache;
   unsigned char subtype; /* The subtype of this ring trust packet.   */
   unsigned char keyorg;  /* The origin of the key (KEYORG_*).        */
   u32 keyupdate;         /* The wall time the key was last updated.  */
   char *url;             /* NULL or the URL of the source.           */
 } PKT_ring_trust;
 
 
 /* A plaintext packet (see RFC 4880, 5.9).  */
 typedef struct {
   /* The length of data in BUF or 0 if unknown.  */
   u32  len;
   /* A buffer containing the data stored in the packet's body.  */
   iobuf_t buf;
   byte new_ctb;
   byte is_partial;      /* partial length encoded */
   /* The data's formatting.  This is either 'b', 't', 'u', 'l' or '1'
      (however, the last two are deprecated).  */
   int mode;
   u32 timestamp;
   /* The name of the file.  This can be at most 255 characters long,
      since namelen is just a byte in the serialized format.  */
   int  namelen;
   char name[1];
 } PKT_plaintext;
 
 typedef struct {
     int  control;
     size_t datalen;
     char data[1];
 } PKT_gpg_control;
 
 /* combine all packets into a union */
 struct packet_struct {
     pkttype_t pkttype;
     union {
 	void *generic;
 	PKT_symkey_enc	*symkey_enc;	/* PKT_SYMKEY_ENC */
 	PKT_pubkey_enc	*pubkey_enc;	/* PKT_PUBKEY_ENC */
 	PKT_onepass_sig *onepass_sig;	/* PKT_ONEPASS_SIG */
 	PKT_signature	*signature;	/* PKT_SIGNATURE */
 	PKT_public_key	*public_key;	/* PKT_PUBLIC_[SUB]KEY */
 	PKT_public_key	*secret_key;	/* PKT_SECRET_[SUB]KEY */
 	PKT_comment	*comment;	/* PKT_COMMENT */
 	PKT_user_id	*user_id;	/* PKT_USER_ID */
 	PKT_compressed	*compressed;	/* PKT_COMPRESSED */
 	PKT_encrypted	*encrypted;	/* PKT_ENCRYPTED[_MDC] */
 	PKT_mdc 	*mdc;		/* PKT_MDC */
 	PKT_plaintext	*plaintext;	/* PKT_PLAINTEXT */
         PKT_gpg_control *gpg_control;   /* PKT_GPG_CONTROL */
     } pkt;
 };
 
 #define init_packet(a) do { (a)->pkttype = 0;		\
 			    (a)->pkt.generic = NULL;	\
 		       } while(0)
 
 
 /* A notation.  See RFC 4880, Section 5.2.3.16.  */
 struct notation
 {
   /* The notation's name.  */
   char *name;
   /* If the notation is human readable, then the value is stored here
      as a NUL-terminated string.  If it is not human readable a human
      readable approximation of the binary value _may_ be stored
      here.  */
   char *value;
   /* Sometimes we want to %-expand the value.  In these cases, we save
      that transformed value here.  */
   char *altvalue;
   /* If the notation is not human readable, then the value is stored
      here.  */
   unsigned char *bdat;
   /* The amount of data stored in BDAT.
 
      Note: if this is 0 and BDAT is NULL, this does not necessarily
      mean that the value is human readable.  It could be that we have
      a 0-length value.  To determine whether the notation is human
      readable, always check if VALUE is not NULL.  This works, because
      if a human-readable value has a length of 0, we will still
      allocate space for the NUL byte.  */
   size_t blen;
   struct
   {
     /* The notation is critical.  */
     unsigned int critical:1;
     /* The notation is human readable.  */
     unsigned int human:1;
     /* The notation should be deleted.  */
     unsigned int ignore:1;
   } flags;
 
   /* A field to facilitate creating a list of notations.  */
   struct notation *next;
 };
 typedef struct notation *notation_t;
 
 /*-- mainproc.c --*/
 void reset_literals_seen(void);
 int proc_packets (ctrl_t ctrl, void *ctx, iobuf_t a );
 int proc_signature_packets (ctrl_t ctrl, void *ctx, iobuf_t a,
 			    strlist_t signedfiles, const char *sigfile );
 int proc_signature_packets_by_fd (ctrl_t ctrl,
                                   void *anchor, IOBUF a, int signed_data_fd );
 int proc_encryption_packets (ctrl_t ctrl, void *ctx, iobuf_t a);
 int list_packets( iobuf_t a );
 
 const byte *issuer_fpr_raw (PKT_signature *sig, size_t *r_len);
 char *issuer_fpr_string (PKT_signature *sig);
 
 /*-- parse-packet.c --*/
 
 
 void register_known_notation (const char *string);
 
 /* Sets the packet list mode to MODE (i.e., whether we are dumping a
    packet or not).  Returns the current mode.  This allows for
    temporarily suspending dumping by doing the following:
 
      int saved_mode = set_packet_list_mode (0);
      ...
      set_packet_list_mode (saved_mode);
 */
 int set_packet_list_mode( int mode );
 
 
 /* A context used with parse_packet.  */
 struct parse_packet_ctx_s
 {
   iobuf_t inp;       /* The input stream with the packets.  */
   struct packet_struct last_pkt; /* The last parsed packet.  */
   int free_last_pkt; /* Indicates that LAST_PKT must be freed.  */
   int skip_meta;     /* Skip ring trust packets.  */
   unsigned int n_parsed_packets;	/* Number of parsed packets.  */
 };
 typedef struct parse_packet_ctx_s *parse_packet_ctx_t;
 
 #define init_parse_packet(a,i) do { \
     (a)->inp = (i);                 \
     (a)->last_pkt.pkttype = 0;      \
     (a)->last_pkt.pkt.generic= NULL;\
     (a)->free_last_pkt = 0;         \
     (a)->skip_meta = 0;             \
     (a)->n_parsed_packets = 0;      \
   } while (0)
 
 #define deinit_parse_packet(a) do { \
     if ((a)->free_last_pkt)         \
       free_packet (NULL, (a));      \
   } while (0)
 
 
 #if DEBUG_PARSE_PACKET
 /* There are debug functions and should not be used directly.  */
 int dbg_search_packet (parse_packet_ctx_t ctx, PACKET *pkt,
                        off_t *retpos, int with_uid,
                        const char* file, int lineno  );
 int dbg_parse_packet (parse_packet_ctx_t ctx, PACKET *ret_pkt,
                       const char *file, int lineno);
 int dbg_copy_all_packets( iobuf_t inp, iobuf_t out,
                           const char* file, int lineno  );
 int dbg_copy_some_packets( iobuf_t inp, iobuf_t out, off_t stopoff,
                            const char* file, int lineno  );
 int dbg_skip_some_packets( iobuf_t inp, unsigned n,
                            const char* file, int lineno	);
 #define search_packet( a,b,c,d )   \
              dbg_search_packet( (a), (b), (c), (d), __FILE__, __LINE__ )
 #define parse_packet( a, b )  \
 	     dbg_parse_packet( (a), (b), __FILE__, __LINE__ )
 #define copy_all_packets( a,b )  \
              dbg_copy_all_packets((a),(b), __FILE__, __LINE__ )
 #define copy_some_packets( a,b,c ) \
              dbg_copy_some_packets((a),(b),(c), __FILE__, __LINE__ )
 #define skip_some_packets( a,b ) \
              dbg_skip_some_packets((a),(b), __FILE__, __LINE__ )
 #else
 /* Return the next valid OpenPGP packet in *PKT.  (This function will
  * skip any packets whose type is 0.)  CTX must have been setup prior to
  * calling this function.
  *
  * Returns 0 on success, -1 if EOF is reached, and an error code
  * otherwise.  In the case of an error, the packet in *PKT may be
  * partially constructed.  As such, even if there is an error, it is
  * necessary to free *PKT to avoid a resource leak.  To detect what
  * has been allocated, clear *PKT before calling this function.  */
 int parse_packet (parse_packet_ctx_t ctx, PACKET *pkt);
 
 /* Return the first OpenPGP packet in *PKT that contains a key (either
  * a public subkey, a public key, a secret subkey or a secret key) or,
  * if WITH_UID is set, a user id.
  *
  * Saves the position in the pipeline of the start of the returned
  * packet (according to iobuf_tell) in RETPOS, if it is not NULL.
  *
  * The return semantics are the same as parse_packet.  */
 int search_packet (parse_packet_ctx_t ctx, PACKET *pkt,
                    off_t *retpos, int with_uid);
 
 /* Copy all packets (except invalid packets, i.e., those with a type
  * of 0) from INP to OUT until either an error occurs or EOF is
  * reached.
  *
  * Returns -1 when end of file is reached or an error code, if an
  * error occurred.  (Note: this function never returns 0, because it
  * effectively keeps going until it gets an EOF.)  */
 int copy_all_packets (iobuf_t inp, iobuf_t out );
 
 /* Like copy_all_packets, but stops at the first packet that starts at
  * or after STOPOFF (as indicated by iobuf_tell).
  *
  * Example: if STOPOFF is 100, the first packet in INP goes from
  * 0 to 110 and the next packet starts at offset 111, then the packet
  * starting at offset 0 will be completely processed (even though it
  * extends beyond STOPOFF) and the packet starting at offset 111 will
  * not be processed at all.  */
 int copy_some_packets (iobuf_t inp, iobuf_t out, off_t stopoff);
 
 /* Skips the next N packets from INP.
  *
  * If parsing a packet returns an error code, then the function stops
  * immediately and returns the error code.  Note: in the case of an
  * error, this function does not indicate how many packets were
  * successfully processed.  */
 int skip_some_packets (iobuf_t inp, unsigned int n);
 #endif
 
 /* Parse a signature packet and store it in *SIG.
 
    The signature packet is read from INP.  The OpenPGP header (the tag
    and the packet's length) have already been read; the next byte read
    from INP should be the first byte of the packet's contents.  The
    packet's type (as extract from the tag) must be passed as PKTTYPE
    and the packet's length must be passed as PKTLEN.  This is used as
    the upper bound on the amount of data read from INP.  If the packet
    is shorter than PKTLEN, the data at the end will be silently
    skipped.  If an error occurs, an error code will be returned.  -1
    means the EOF was encountered.  0 means parsing was successful.  */
 int parse_signature( iobuf_t inp, int pkttype, unsigned long pktlen,
 		     PKT_signature *sig );
 
 /* Given a subpacket area (typically either PKT_signature.hashed or
    PKT_signature.unhashed), either:
 
      - test whether there are any subpackets with the critical bit set
        that we don't understand,
 
      - list the subpackets, or,
 
      - find a subpacket with a specific type.
 
    REQTYPE indicates the type of operation.
 
    If REQTYPE is SIGSUBPKT_TEST_CRITICAL, then this function checks
    whether there are any subpackets that have the critical bit and
    which GnuPG cannot handle.  If GnuPG understands all subpackets
    whose critical bit is set, then this function returns simply
    returns SUBPKTS.  If there is a subpacket whose critical bit is set
    and which GnuPG does not understand, then this function returns
    NULL and, if START is not NULL, sets *START to the 1-based index of
    the subpacket that violates the constraint.
 
    If REQTYPE is SIGSUBPKT_LIST_HASHED or SIGSUBPKT_LIST_UNHASHED, the
    packets are dumped.  Note: if REQTYPE is SIGSUBPKT_LIST_HASHED,
    this function does not check whether the hash is correct; this is
    merely an indication of the section that the subpackets came from.
 
    If REQTYPE is anything else, then this function interprets the
    values as a subpacket type and looks for the first subpacket with
    that type.  If such a packet is found, *CRITICAL (if not NULL) is
    set if the critical bit was set, *RET_N is set to the offset of the
    subpacket's content within the SUBPKTS buffer, *START is set to the
    1-based index of the subpacket within the buffer, and returns
    &SUBPKTS[*RET_N].
 
    *START is the number of initial subpackets to not consider.  Thus,
    if *START is 2, then the first 2 subpackets are ignored.  */
 const byte *enum_sig_subpkt ( const subpktarea_t *subpkts,
                               sigsubpkttype_t reqtype,
                               size_t *ret_n, int *start, int *critical );
 
 /* Shorthand for:
 
      enum_sig_subpkt (buffer, reqtype, ret_n, NULL, NULL); */
 const byte *parse_sig_subpkt ( const subpktarea_t *buffer,
                                sigsubpkttype_t reqtype,
                                size_t *ret_n );
 
 /* This calls parse_sig_subpkt first on the hashed signature area in
    SIG and then, if that returns NULL, calls parse_sig_subpkt on the
    unhashed subpacket area in SIG.  */
 const byte *parse_sig_subpkt2 ( PKT_signature *sig,
                                 sigsubpkttype_t reqtype);
 
 /* Returns whether the N byte large buffer BUFFER is sufficient to
    hold a subpacket of type TYPE.  Note: the buffer refers to the
    contents of the subpacket (not the header) and it must already be
    initialized: for some subpackets, it checks some internal
    constraints.
 
    Returns 0 if the size is acceptable.  Returns -2 if the buffer is
    definitely too short.  To check for an error, check whether the
    return value is less than 0.  */
 int parse_one_sig_subpkt( const byte *buffer, size_t n, int type );
 
 /* Looks for revocation key subpackets (see RFC 4880 5.2.3.15) in the
    hashed area of the signature packet.  Any that are found are added
    to SIG->REVKEY and SIG->NUMREVKEYS is updated appropriately.  */
 void parse_revkeys(PKT_signature *sig);
 
 /* Extract the attributes from the buffer at UID->ATTRIB_DATA and
    update UID->ATTRIBS and UID->NUMATTRIBS accordingly.  */
 int parse_attribute_subpkts(PKT_user_id *uid);
 
 /* Set the UID->NAME field according to the attributes.  MAX_NAMELEN
    must be at least 71.  */
 void make_attribute_uidname(PKT_user_id *uid, size_t max_namelen);
 
 /* Allocate and initialize a new GPG control packet.  DATA is the data
    to save in the packet.  */
 PACKET *create_gpg_control ( ctrlpkttype_t type,
                              const byte *data,
                              size_t datalen );
 
 /*-- build-packet.c --*/
 int build_packet (iobuf_t out, PACKET *pkt);
 gpg_error_t build_packet_and_meta (iobuf_t out, PACKET *pkt);
 gpg_error_t gpg_mpi_write (iobuf_t out, gcry_mpi_t a);
 gpg_error_t gpg_mpi_write_nohdr (iobuf_t out, gcry_mpi_t a);
 u32 calc_packet_length( PACKET *pkt );
 void build_sig_subpkt( PKT_signature *sig, sigsubpkttype_t type,
 			const byte *buffer, size_t buflen );
 void build_sig_subpkt_from_sig (PKT_signature *sig, PKT_public_key *pksk);
 int  delete_sig_subpkt(subpktarea_t *buffer, sigsubpkttype_t type );
 void build_attribute_subpkt(PKT_user_id *uid,byte type,
 			    const void *buf,u32 buflen,
 			    const void *header,u32 headerlen);
 struct notation *string_to_notation(const char *string,int is_utf8);
 struct notation *blob_to_notation(const char *name,
                                   const char *data, size_t len);
 struct notation *sig_to_notation(PKT_signature *sig);
 void free_notation(struct notation *notation);
 
 /*-- free-packet.c --*/
 void free_symkey_enc( PKT_symkey_enc *enc );
 void free_pubkey_enc( PKT_pubkey_enc *enc );
 void free_seckey_enc( PKT_signature *enc );
 void release_public_key_parts( PKT_public_key *pk );
 void free_public_key( PKT_public_key *key );
 void free_attributes(PKT_user_id *uid);
 void free_user_id( PKT_user_id *uid );
 void free_comment( PKT_comment *rem );
 void free_packet (PACKET *pkt, parse_packet_ctx_t parsectx);
 prefitem_t *copy_prefs (const prefitem_t *prefs);
 PKT_public_key *copy_public_key( PKT_public_key *d, PKT_public_key *s );
 PKT_signature *copy_signature( PKT_signature *d, PKT_signature *s );
 PKT_user_id *scopy_user_id (PKT_user_id *sd );
 int cmp_public_keys( PKT_public_key *a, PKT_public_key *b );
 int cmp_signatures( PKT_signature *a, PKT_signature *b );
 int cmp_user_ids( PKT_user_id *a, PKT_user_id *b );
 
 
 /*-- sig-check.c --*/
 /* Check a signature.  This is shorthand for check_signature2 with
    the unnamed arguments passed as NULL.  */
 int check_signature (ctrl_t ctrl, PKT_signature *sig, gcry_md_hd_t digest);
 
 /* Check a signature.  Looks up the public key from the key db.  (If
  * R_PK is not NULL, it is stored at RET_PK.)  DIGEST contains a
  * valid hash context that already includes the signed data.  This
  * function adds the relevant meta-data to the hash before finalizing
  * it and verifying the signature.  FOCRED_PK is usually NULL. */
 gpg_error_t check_signature2 (ctrl_t ctrl,
                               PKT_signature *sig, gcry_md_hd_t digest,
                               PKT_public_key *forced_pk,
                               u32 *r_expiredate, int *r_expired, int *r_revoked,
                               PKT_public_key **r_pk);
 
 
 /*-- pubkey-enc.c --*/
 gpg_error_t get_session_key (ctrl_t ctrl, PKT_pubkey_enc *k, DEK *dek);
 gpg_error_t get_override_session_key (DEK *dek, const char *string);
 
 /*-- compress.c --*/
 int handle_compressed (ctrl_t ctrl, void *ctx, PKT_compressed *cd,
 		       int (*callback)(iobuf_t, void *), void *passthru );
 
 /*-- decrypt-data.c --*/
 int decrypt_data (ctrl_t ctrl, void *ctx, PKT_encrypted *ed, DEK *dek,
                   int *compliance_error);
 
 /*-- plaintext.c --*/
 gpg_error_t get_output_file (const byte *embedded_name, int embedded_namelen,
                              iobuf_t data, char **fnamep, estream_t *fpp);
 int handle_plaintext( PKT_plaintext *pt, md_filter_context_t *mfx,
 					int nooutput, int clearsig );
 int ask_for_detached_datafile( gcry_md_hd_t md, gcry_md_hd_t md2,
 			       const char *inname, int textmode );
 
 /*-- sign.c --*/
 int make_keysig_packet (ctrl_t ctrl,
                         PKT_signature **ret_sig, PKT_public_key *pk,
 			PKT_user_id *uid, PKT_public_key *subpk,
 			PKT_public_key *pksk, int sigclass, int digest_algo,
 			u32 timestamp, u32 duration,
 			int (*mksubpkt)(PKT_signature *, void *),
 			void *opaque,
                         const char *cache_nonce);
 gpg_error_t update_keysig_packet (ctrl_t ctrl,
                       PKT_signature **ret_sig,
                       PKT_signature *orig_sig,
                       PKT_public_key *pk,
                       PKT_user_id *uid,
                       PKT_public_key *subpk,
                       PKT_public_key *pksk,
                       int (*mksubpkt)(PKT_signature *, void *),
                       void *opaque   );
 
 /*-- keygen.c --*/
 PKT_user_id *generate_user_id (kbnode_t keyblock, const char *uidstr);
 
 #endif /*G10_PACKET_H*/