diff --git a/dirmngr/dirmngr.c b/dirmngr/dirmngr.c
index e1f3a1dcd..a94257e5c 100644
--- a/dirmngr/dirmngr.c
+++ b/dirmngr/dirmngr.c
@@ -1,2508 +1,2527 @@
 /* dirmngr.c - Keyserver and X.509 LDAP access
  * Copyright (C) 2002 Klarälvdalens Datakonsult AB
  * Copyright (C) 2003-2004, 2006-2007, 2008, 2010-2011, 2020-2021 g10 Code GmbH
  * Copyright (C) 2014 Werner Koch
  *
  * 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/>.
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
 #include <config.h>
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>
 #include <errno.h>
 #include <assert.h>
 #include <time.h>
 #include <fcntl.h>
 #ifndef HAVE_W32_SYSTEM
 #include <sys/socket.h>
 #include <sys/un.h>
 #endif
 #include <sys/stat.h>
 #include <unistd.h>
 #ifdef HAVE_SIGNAL_H
 # include <signal.h>
 #endif
 #ifdef HAVE_INOTIFY_INIT
 # include <sys/inotify.h>
 #endif /*HAVE_INOTIFY_INIT*/
 #include <npth.h>
 
 #include "dirmngr-err.h"
 
 #if  HTTP_USE_NTBTLS
 # include <ntbtls.h>
 #elif HTTP_USE_GNUTLS
 # include <gnutls/gnutls.h>
 #endif /*HTTP_USE_GNUTLS*/
 
 
 #define INCLUDED_BY_MAIN_MODULE 1
 #define GNUPG_COMMON_NEED_AFLOCAL
 #include "dirmngr.h"
 
 #include <assuan.h>
 
 #include "certcache.h"
 #include "crlcache.h"
 #include "crlfetch.h"
 #include "misc.h"
 #if USE_LDAP
 # include "ldapserver.h"
 #endif
 #include "../common/asshelp.h"
 #if USE_LDAP
 # include "ldap-wrapper.h"
 #endif
 #include "../common/init.h"
 #include "../common/gc-opt-flags.h"
 #include "dns-stuff.h"
 #include "http-common.h"
 
 #ifndef ENAMETOOLONG
 # define ENAMETOOLONG EINVAL
 #endif
 
 
 enum cmd_and_opt_values {
   aNull = 0,
   oCsh		  = 'c',
   oQuiet	  = 'q',
   oSh		  = 's',
   oVerbose	  = 'v',
   oNoVerbose = 500,
 
   aServer,
   aDaemon,
   aSupervised,
   aListCRLs,
   aLoadCRL,
   aFetchCRL,
   aShutdown,
   aFlush,
   aGPGConfList,
   aGPGConfTest,
   aGPGConfVersions,
 
   oOptions,
   oDebug,
   oDebugAll,
   oDebugWait,
   oDebugLevel,
   oGnutlsDebug,
   oDebugCacheExpiredCerts,
   oNoGreeting,
   oNoOptions,
   oHomedir,
   oNoDetach,
   oLogFile,
   oBatch,
   oDisableHTTP,
   oDisableLDAP,
   oDisableIPv4,
   oDisableIPv6,
   oIgnoreLDAPDP,
   oIgnoreHTTPDP,
   oIgnoreOCSPSvcUrl,
   oHonorHTTPProxy,
   oHTTPProxy,
   oLDAPProxy,
   oOnlyLDAPProxy,
   oLDAPServer,
   oLDAPFile,
   oLDAPTimeout,
   oLDAPAddServers,
   oOCSPResponder,
   oOCSPSigner,
   oOCSPMaxClockSkew,
   oOCSPMaxPeriod,
   oOCSPCurrentPeriod,
   oMaxReplies,
   oHkpCaCert,
   oFakedSystemTime,
   oForce,
   oAllowOCSP,
   oAllowVersionCheck,
   oStealSocket,
   oSocketName,
   oLDAPWrapperProgram,
   oHTTPWrapperProgram,
   oIgnoreCert,
   oIgnoreCertExtension,
   oUseTor,
   oNoUseTor,
   oKeyServer,
   oNameServer,
   oDisableCheckOwnSocket,
   oStandardResolver,
   oRecursiveResolver,
   oResolverTimeout,
   oConnectTimeout,
   oConnectQuickTimeout,
   oListenBacklog,
+  oCompatibilityFlags,
   aTest
 };
 
 
 
 static ARGPARSE_OPTS opts[] = {
 
   ARGPARSE_c (aGPGConfList, "gpgconf-list", "@"),
   ARGPARSE_c (aGPGConfTest, "gpgconf-test", "@"),
   ARGPARSE_c (aGPGConfVersions, "gpgconf-versions", "@"),
 
   ARGPARSE_group (300, N_("@Commands:\n ")),
 
   ARGPARSE_c (aServer,   "server",  N_("run in server mode (foreground)") ),
   ARGPARSE_c (aDaemon,   "daemon",  N_("run in daemon mode (background)") ),
 #ifndef HAVE_W32_SYSTEM
   ARGPARSE_c (aSupervised,  "supervised", N_("run in supervised mode")),
 #endif
   ARGPARSE_c (aListCRLs, "list-crls", N_("list the contents of the CRL cache")),
   ARGPARSE_c (aLoadCRL,  "load-crl", N_("|FILE|load CRL from FILE into cache")),
   ARGPARSE_c (aFetchCRL, "fetch-crl", N_("|URL|fetch a CRL from URL")),
   ARGPARSE_c (aShutdown, "shutdown",  N_("shutdown the dirmngr")),
   ARGPARSE_c (aFlush,    "flush",     N_("flush the cache")),
 
 
   ARGPARSE_header (NULL, N_("Options used for startup")),
 
   ARGPARSE_s_n (oNoDetach, "no-detach", N_("do not detach from the console")),
   ARGPARSE_s_n (oSh,       "sh",        N_("sh-style command output")),
   ARGPARSE_s_n (oCsh,      "csh",       N_("csh-style command output")),
   ARGPARSE_s_n (oStealSocket, "steal-socket", "@"),
   ARGPARSE_s_s (oHomedir, "homedir", "@"),
   ARGPARSE_conffile (oOptions,  "options", N_("|FILE|read options from FILE")),
   ARGPARSE_noconffile (oNoOptions, "no-options", "@"),
 
 
   ARGPARSE_header ("Monitor", N_("Options controlling the diagnostic output")),
 
   ARGPARSE_s_n (oVerbose,  "verbose",   N_("verbose")),
   ARGPARSE_s_n (oQuiet,    "quiet",     N_("be somewhat more quiet")),
   ARGPARSE_s_n (oNoGreeting, "no-greeting", "@"),
   ARGPARSE_s_s (oDebugLevel, "debug-level",
                 N_("|LEVEL|set the debugging level to LEVEL")),
   ARGPARSE_s_s (oDebug,    "debug", "@"),
   ARGPARSE_s_n (oDebugAll, "debug-all", "@"),
   ARGPARSE_s_i (oGnutlsDebug, "gnutls-debug", "@"),
   ARGPARSE_s_i (oGnutlsDebug, "tls-debug", "@"),
   ARGPARSE_s_i (oDebugWait, "debug-wait", "@"),
   ARGPARSE_s_s (oLogFile,  "log-file",
                 N_("|FILE|write server mode logs to FILE")),
 
 
   ARGPARSE_header ("Configuration",
                    N_("Options controlling the configuration")),
 
   ARGPARSE_s_n (oAllowVersionCheck, "allow-version-check",
                 N_("allow online software version check")),
   ARGPARSE_s_i (oListenBacklog, "listen-backlog", "@"),
   ARGPARSE_s_i (oMaxReplies, "max-replies",
                 N_("|N|do not return more than N items in one query")),
   ARGPARSE_s_u (oFakedSystemTime, "faked-system-time", "@"), /*(epoch time)*/
   ARGPARSE_s_n (oDisableCheckOwnSocket, "disable-check-own-socket", "@"),
   ARGPARSE_s_s (oIgnoreCert,"ignore-cert", "@"),
   ARGPARSE_s_s (oIgnoreCertExtension,"ignore-cert-extension", "@"),
 
 
   ARGPARSE_header ("Network", N_("Network related options")),
 
   ARGPARSE_s_n (oUseTor, "use-tor", N_("route all network traffic via Tor")),
   ARGPARSE_s_n (oNoUseTor, "no-use-tor", "@"),
   ARGPARSE_s_n (oDisableIPv4, "disable-ipv4", "@"),
   ARGPARSE_s_n (oDisableIPv6, "disable-ipv6", "@"),
   ARGPARSE_s_n (oStandardResolver, "standard-resolver", "@"),
   ARGPARSE_s_n (oRecursiveResolver, "recursive-resolver", "@"),
   ARGPARSE_s_i (oResolverTimeout, "resolver-timeout", "@"),
   ARGPARSE_s_s (oNameServer, "nameserver", "@"),
   ARGPARSE_s_i (oConnectTimeout, "connect-timeout", "@"),
   ARGPARSE_s_i (oConnectQuickTimeout, "connect-quick-timeout", "@"),
 
 
   ARGPARSE_header ("Keyserver", N_("Configuration for Keyservers")),
 
   ARGPARSE_s_s (oKeyServer, "keyserver",
                 N_("|URL|use keyserver at URL")),
   ARGPARSE_s_s (oHkpCaCert, "hkp-cacert",
                 N_("|FILE|use the CA certificates in FILE for HKP over TLS")),
 
 
   ARGPARSE_header ("HTTP", N_("Configuration for HTTP servers")),
 
   ARGPARSE_s_n (oDisableHTTP, "disable-http", N_("inhibit the use of HTTP")),
   ARGPARSE_s_n (oIgnoreHTTPDP,"ignore-http-dp",
                 N_("ignore HTTP CRL distribution points")),
   ARGPARSE_s_s (oHTTPProxy,  "http-proxy",
                 N_("|URL|redirect all HTTP requests to URL")),
   ARGPARSE_s_n (oHonorHTTPProxy, "honor-http-proxy",
                 N_("use system's HTTP proxy setting")),
   ARGPARSE_s_s (oLDAPWrapperProgram, "ldap-wrapper-program", "@"),
 
 
   ARGPARSE_header ("LDAP", N_("Configuration of LDAP servers to use")),
 
   ARGPARSE_s_n (oDisableLDAP, "disable-ldap", N_("inhibit the use of LDAP")),
   ARGPARSE_s_n (oIgnoreLDAPDP,"ignore-ldap-dp",
                 N_("ignore LDAP CRL distribution points")),
   ARGPARSE_s_s (oLDAPProxy,  "ldap-proxy",
                 N_("|HOST|use HOST for LDAP queries")),
   ARGPARSE_s_n (oOnlyLDAPProxy, "only-ldap-proxy",
                 N_("do not use fallback hosts with --ldap-proxy")),
   ARGPARSE_s_s (oLDAPServer, "ldapserver",
                 N_("|SPEC|use this keyserver to lookup keys")),
   ARGPARSE_s_s (oLDAPFile, "ldapserverlist-file",
                 N_("|FILE|read LDAP server list from FILE")),
   ARGPARSE_s_n (oLDAPAddServers, "add-servers",
                 N_("add new servers discovered in CRL distribution"
                    " points to serverlist")),
   ARGPARSE_s_i (oLDAPTimeout, "ldaptimeout",
                 N_("|N|set LDAP timeout to N seconds")),
 
 
   ARGPARSE_header ("OCSP", N_("Configuration for OCSP")),
 
   ARGPARSE_s_n (oAllowOCSP, "allow-ocsp", N_("allow sending OCSP requests")),
   ARGPARSE_s_n (oIgnoreOCSPSvcUrl, "ignore-ocsp-service-url",
                 N_("ignore certificate contained OCSP service URLs")),
   ARGPARSE_s_s (oOCSPResponder, "ocsp-responder",
                 N_("|URL|use OCSP responder at URL")),
   ARGPARSE_s_s (oOCSPSigner, "ocsp-signer",
                 N_("|FPR|OCSP response signed by FPR")),
   ARGPARSE_s_i (oOCSPMaxClockSkew, "ocsp-max-clock-skew", "@"),
   ARGPARSE_s_i (oOCSPMaxPeriod,    "ocsp-max-period", "@"),
   ARGPARSE_s_i (oOCSPCurrentPeriod, "ocsp-current-period", "@"),
 
 
   ARGPARSE_header (NULL, N_("Other options")),
 
   ARGPARSE_s_n (oForce,    "force",    N_("force loading of outdated CRLs")),
 
   ARGPARSE_s_s (oSocketName, "socket-name", "@"),  /* Only for debugging.  */
   ARGPARSE_s_n (oDebugCacheExpiredCerts, "debug-cache-expired-certs", "@"),
+  ARGPARSE_s_s (oCompatibilityFlags, "compatibility-flags", "@"),
 
   ARGPARSE_header (NULL, ""),  /* Stop the header group.  */
 
   /* Not yet used options.  */
   ARGPARSE_s_n (oBatch,    "batch",       "@"),
   ARGPARSE_s_s (oHTTPWrapperProgram, "http-wrapper-program", "@"),
 
 
   ARGPARSE_group (302,N_("@\n(See the \"info\" manual for a complete listing "
                          "of all commands and options)\n")),
 
   ARGPARSE_end ()
 };
 
 /* The list of supported debug flags.  */
 static struct debug_flags_s debug_flags [] =
   {
     { DBG_X509_VALUE   , "x509"    },
     { DBG_CRYPTO_VALUE , "crypto"  },
     { DBG_MEMORY_VALUE , "memory"  },
     { DBG_CACHE_VALUE  , "cache"   },
     { DBG_MEMSTAT_VALUE, "memstat" },
     { DBG_HASHING_VALUE, "hashing" },
     { DBG_IPC_VALUE    , "ipc"     },
     { DBG_DNS_VALUE    , "dns"     },
     { DBG_NETWORK_VALUE, "network" },
     { DBG_LOOKUP_VALUE , "lookup"  },
     { DBG_EXTPROG_VALUE, "extprog" },
     { 77, NULL } /* 77 := Do not exit on "help" or "?".  */
   };
 
+/* The list of compatibility flags.  */
+static struct compatibility_flags_s compatibility_flags [] =
+  {
+    { 0, NULL }
+  };
+
+
 #define DEFAULT_MAX_REPLIES 10
 #define DEFAULT_LDAP_TIMEOUT 15  /* seconds */
 
 #define DEFAULT_CONNECT_TIMEOUT       (15*1000)  /* 15 seconds */
 #define DEFAULT_CONNECT_QUICK_TIMEOUT ( 2*1000)  /*  2 seconds */
 
 /* For the cleanup handler we need to keep track of the socket's name.  */
 static const char *socket_name;
 /* If the socket has been redirected, this is the name of the
    redirected socket..  */
 static const char *redir_socket_name;
 
 /* We need to keep track of the server's nonces (these are dummies for
    POSIX systems). */
 static assuan_sock_nonce_t socket_nonce;
 
 /* Value for the listen() backlog argument.
  * Change at runtime with --listen-backlog.  */
 static int listen_backlog = 64;
 
 /* Only if this flag has been set will we remove the socket file.  */
 static int cleanup_socket;
 
 /* Keep track of the current log file so that we can avoid updating
    the log file after a SIGHUP if it didn't changed. Malloced. */
 static char *current_logfile;
 
 /* Helper to implement --debug-level. */
 static const char *debug_level;
 
 /* Helper to set the NTBTLS or GNUTLS log level.  */
 static int opt_gnutls_debug = -1;
 
 /* Flag indicating that a shutdown has been requested.  */
 static volatile int shutdown_pending;
 
 /* Flags to indicate that we shall not watch our own socket. */
 static int disable_check_own_socket;
 
 /* Flag indicating to start the daemon even if one already runs.  */
 static int steal_socket;
 
 
 /* Flag to control the Tor mode.  */
 static enum
   { TOR_MODE_AUTO = 0,  /* Switch to NO or YES         */
     TOR_MODE_NEVER,     /* Never use Tor.              */
     TOR_MODE_NO,        /* Do not use Tor              */
     TOR_MODE_YES,       /* Use Tor                     */
     TOR_MODE_FORCE      /* Force using Tor             */
   } tor_mode;
 
 
 /* Counter for the active connections.  */
 static int active_connections;
 
 /* This flag is set by any network access and used by the housekeeping
  * thread to run background network tasks.  */
 static int network_activity_seen;
 
 /* A list of filenames registred with --hkp-cacert.  */
 static strlist_t hkp_cacert_filenames;
 
 /* A flag used to clear the list of ldapservers iff --ldapserver is
  * given on the command line or one of the conf files. In this case we
  * want to clear all old specifications through the legacy
  * dirmngr_ldapservers.conf. */
 static int ldapserver_list_needs_reset;
 
 /* The timer tick used for housekeeping stuff.  The second constant is used when a shutdown is pending.  */
 #define TIMERTICK_INTERVAL           (60)
 #define TIMERTICK_INTERVAL_SHUTDOWN  (4)
 
 /* How oft to run the housekeeping.  */
 #define HOUSEKEEPING_INTERVAL      (600)
 
 
 /* This union is used to avoid compiler warnings in case a pointer is
    64 bit and an int 32 bit.  We store an integer in a pointer and get
    it back later (npth_getspecific et al.).  */
 union int_and_ptr_u
 {
   int  aint;
   assuan_fd_t afd;
   void *aptr;
 };
 
 
 
 /* The key used to store the current file descriptor in the thread
    local storage.  We use this in conjunction with the
    log_set_pid_suffix_cb feature.  */
 #ifndef HAVE_W32_SYSTEM
 static npth_key_t my_tlskey_current_fd;
 #endif
 
 /* Prototypes. */
 static void cleanup (void);
 #if USE_LDAP
 static ldap_server_t parse_ldapserver_file (const char* filename, int ienoent);
 #endif /*USE_LDAP*/
 static fingerprint_list_t parse_fingerprint_item (const char *string,
                                                   const  char *optionname,
                                                   int want_binary);
 static void netactivity_action (void);
 static void handle_connections (assuan_fd_t listen_fd);
 static void gpgconf_versions (void);
 
 
 /* NPth wrapper function definitions. */
 ASSUAN_SYSTEM_NPTH_IMPL;
 
 static const char *
 my_strusage( int level )
 {
   const char *p;
   switch ( level )
     {
     case  9: p = "GPL-3.0-or-later"; break;
     case 11: p = "@DIRMNGR@ (@GNUPG@)";
       break;
     case 13: p = VERSION; break;
     case 14: p = GNUPG_DEF_COPYRIGHT_LINE; break;
     case 17: p = PRINTABLE_OS_NAME; break;
       /* TRANSLATORS: @EMAIL@ will get replaced by the actual bug
          reporting address.  This is so that we can change the
          reporting address without breaking the translations.  */
     case 19: p = _("Please report bugs to <@EMAIL@>.\n"); break;
     case 49: p = PACKAGE_BUGREPORT; break;
     case 1:
     case 40: p = _("Usage: @DIRMNGR@ [options] (-h for help)");
       break;
     case 41: p = _("Syntax: @DIRMNGR@ [options] [command [args]]\n"
                    "Keyserver, CRL, and OCSP access for @GNUPG@\n");
       break;
 
     default: p = NULL;
     }
   return p;
 }
 
 
 /* Callback from libksba to hash a provided buffer.  Our current
    implementation does only allow SHA-1 for hashing. This may be
    extended by mapping the name, testing for algorithm availibility
    and adjust the length checks accordingly. */
 static gpg_error_t
 my_ksba_hash_buffer (void *arg, const char *oid,
                      const void *buffer, size_t length, size_t resultsize,
                      unsigned char *result, size_t *resultlen)
 {
   (void)arg;
 
   if (oid && strcmp (oid, "1.3.14.3.2.26"))
     return gpg_error (GPG_ERR_NOT_SUPPORTED);
   if (resultsize < 20)
     return gpg_error (GPG_ERR_BUFFER_TOO_SHORT);
   gcry_md_hash_buffer (2, result, buffer, length);
   *resultlen = 20;
   return 0;
 }
 
 
 /* GNUTLS log function callback.  */
 #ifdef HTTP_USE_GNUTLS
 static void
 my_gnutls_log (int level, const char *text)
 {
   int n;
 
   n = strlen (text);
   while (n && text[n-1] == '\n')
     n--;
 
   log_debug ("gnutls:L%d: %.*s\n", level, n, text);
 }
 #endif /*HTTP_USE_GNUTLS*/
 
 /* Setup the debugging.  With a LEVEL of NULL only the active debug
    flags are propagated to the subsystems.  With LEVEL set, a specific
    set of debug flags is set; thus overriding all flags already
    set. */
 static void
 set_debug (void)
 {
   int numok = (debug_level && digitp (debug_level));
   int numlvl = numok? atoi (debug_level) : 0;
 
   if (!debug_level)
     ;
   else if (!strcmp (debug_level, "none") || (numok && numlvl < 1))
     opt.debug = 0;
   else if (!strcmp (debug_level, "basic") || (numok && numlvl <= 2))
     opt.debug = DBG_IPC_VALUE;
   else if (!strcmp (debug_level, "advanced") || (numok && numlvl <= 5))
     opt.debug = (DBG_IPC_VALUE|DBG_X509_VALUE|DBG_LOOKUP_VALUE);
   else if (!strcmp (debug_level, "expert") || (numok && numlvl <= 8))
     opt.debug = (DBG_IPC_VALUE|DBG_X509_VALUE|DBG_LOOKUP_VALUE
                  |DBG_CACHE_VALUE|DBG_CRYPTO_VALUE);
   else if (!strcmp (debug_level, "guru") || numok)
     {
       opt.debug = ~0;
       /* Unless the "guru" string has been used we don't want to allow
          hashing debugging.  The rationale is that people tend to
          select the highest debug value and would then clutter their
          disk with debug files which may reveal confidential data.  */
       if (numok)
         opt.debug &= ~(DBG_HASHING_VALUE);
     }
   else
     {
       log_error (_("invalid debug-level '%s' given\n"), debug_level);
       log_info (_("valid debug levels are: %s\n"),
                 "none, basic, advanced, expert, guru");
       opt.debug = 0; /* Reset debugging, so that prior debug
                         statements won't have an undesired effect. */
     }
 
 
   if (opt.debug && !opt.verbose)
     {
       opt.verbose = 1;
       gcry_control (GCRYCTL_SET_VERBOSITY, (int)opt.verbose);
     }
   if (opt.debug && opt.quiet)
     opt.quiet = 0;
 
   if (opt.debug & DBG_CRYPTO_VALUE )
     gcry_control (GCRYCTL_SET_DEBUG_FLAGS, 1);
 
 #if HTTP_USE_NTBTLS
   if (opt_gnutls_debug >= 0)
     {
       ntbtls_set_debug (opt_gnutls_debug, NULL, NULL);
     }
 #elif HTTP_USE_GNUTLS
   if (opt_gnutls_debug >= 0)
     {
       gnutls_global_set_log_function (my_gnutls_log);
       gnutls_global_set_log_level (opt_gnutls_debug);
     }
 #endif /*HTTP_USE_GNUTLS*/
 
   if (opt.debug)
     parse_debug_flag (NULL, &opt.debug, debug_flags);
 }
 
 
 static void
 set_tor_mode (void)
 {
   if (dirmngr_use_tor ())
     {
       /* Enable Tor mode and when called again force a new curcuit
        * (e.g. on SIGHUP).  */
       enable_dns_tormode (1);
       if (assuan_sock_set_flag (ASSUAN_INVALID_FD, "tor-mode", 1))
         {
           log_error ("error enabling Tor mode: %s\n", strerror (errno));
           log_info ("(is your Libassuan recent enough?)\n");
         }
     }
   else
     disable_dns_tormode ();
 }
 
 
 /* Return true if Tor shall be used.  */
 int
 dirmngr_use_tor (void)
 {
   if (tor_mode == TOR_MODE_AUTO)
     {
       /* Figure out whether Tor is running.  */
       assuan_fd_t sock;
 
       sock = assuan_sock_connect_byname (NULL, 0, 0, NULL, ASSUAN_SOCK_TOR);
       if (sock == ASSUAN_INVALID_FD)
         tor_mode = TOR_MODE_NO;
       else
         {
           tor_mode = TOR_MODE_YES;
           assuan_sock_close (sock);
         }
     }
 
   if (tor_mode == TOR_MODE_FORCE)
     return 2; /* Use Tor (using 2 to indicate force mode) */
   else if (tor_mode == TOR_MODE_YES)
     return 1; /* Use Tor */
   else
     return 0; /* Do not use Tor.  */
 }
 
 
 /* This is somewhat similar to dirmngr_use_tor but avoids a trial
  * connect and may thus be faster for this special case.  */
 int
 dirmngr_never_use_tor_p (void)
 {
   return tor_mode == TOR_MODE_NEVER;
 }
 
 
 static void
 wrong_args (const char *text)
 {
   es_fprintf (es_stderr, _("usage: %s [options] "), DIRMNGR_NAME);
   es_fputs (text, es_stderr);
   es_putc ('\n', es_stderr);
   dirmngr_exit (2);
 }
 
 
 /* Helper to stop the reaper thread for the ldap wrapper.  */
 static void
 shutdown_reaper (void)
 {
 #if USE_LDAP
   ldap_wrapper_wait_connections ();
 #endif
 }
 
 
 /* Handle options which are allowed to be reset after program start.
    Return true if the current option in PARGS could be handled and
    false if not.  As a special feature, passing a value of NULL for
    PARGS, resets the options to the default.  REREAD should be set
    true if it is not the initial option parsing. */
 static int
 parse_rereadable_options (ARGPARSE_ARGS *pargs, int reread)
 {
   if (!pargs)
     { /* Reset mode. */
       opt.quiet = 0;
       opt.verbose = 0;
       opt.debug = 0;
       opt.ldap_wrapper_program = NULL;
       opt.disable_http = 0;
       opt.disable_ldap = 0;
       opt.honor_http_proxy = 0;
       opt.http_proxy = NULL;
       opt.ldap_proxy = NULL;
       opt.only_ldap_proxy = 0;
       opt.ignore_http_dp = 0;
       opt.ignore_ldap_dp = 0;
       opt.ignore_ocsp_service_url = 0;
       opt.allow_ocsp = 0;
       opt.allow_version_check = 0;
       opt.ocsp_responder = NULL;
       opt.ocsp_max_clock_skew = 10 * 60;      /* 10 minutes.  */
       opt.ocsp_max_period = 90 * 86400;       /* 90 days.  */
       opt.ocsp_current_period = 3 * 60 * 60;  /* 3 hours. */
       opt.max_replies = DEFAULT_MAX_REPLIES;
       while (opt.ocsp_signer)
         {
           fingerprint_list_t tmp = opt.ocsp_signer->next;
           xfree (opt.ocsp_signer);
           opt.ocsp_signer = tmp;
         }
       while (opt.ignored_certs)
         {
           fingerprint_list_t tmp = opt.ignored_certs->next;
           xfree (opt.ignored_certs);
           opt.ignored_certs = tmp;
         }
       FREE_STRLIST (opt.ignored_cert_extensions);
       http_register_tls_ca (NULL);
       FREE_STRLIST (hkp_cacert_filenames);
       FREE_STRLIST (opt.keyserver);
       /* Note: We do not allow resetting of TOR_MODE_FORCE at runtime.  */
       if (tor_mode != TOR_MODE_FORCE)
         tor_mode = TOR_MODE_AUTO;
       disable_check_own_socket = 0;
       enable_standard_resolver (0);
       set_dns_timeout (0);
       opt.connect_timeout = 0;
       opt.connect_quick_timeout = 0;
       opt.ldaptimeout = DEFAULT_LDAP_TIMEOUT;
       ldapserver_list_needs_reset = 1;
       opt.debug_cache_expired_certs = 0;
+      opt.compat_flags = 0;
       return 1;
     }
 
   switch (pargs->r_opt)
     {
     case oQuiet:   opt.quiet = 1; break;
     case oVerbose: opt.verbose++; break;
     case oDebug:
       parse_debug_flag (pargs->r.ret_str, &opt.debug, debug_flags);
       break;
     case oDebugAll: opt.debug = ~0; break;
     case oDebugLevel: debug_level = pargs->r.ret_str; break;
     case oGnutlsDebug: opt_gnutls_debug = pargs->r.ret_int; break;
 
     case oLogFile:
       if (!reread)
         return 0; /* Not handled. */
       if (!current_logfile || !pargs->r.ret_str
           || strcmp (current_logfile, pargs->r.ret_str))
         {
           log_set_file (pargs->r.ret_str);
           xfree (current_logfile);
           current_logfile = xtrystrdup (pargs->r.ret_str);
         }
       break;
 
     case oDisableCheckOwnSocket: disable_check_own_socket = 1; break;
 
     case oLDAPWrapperProgram:
       opt.ldap_wrapper_program = pargs->r.ret_str;
       break;
     case oHTTPWrapperProgram:
       opt.http_wrapper_program = pargs->r.ret_str;
       break;
 
     case oDisableHTTP: opt.disable_http = 1; break;
     case oDisableLDAP: opt.disable_ldap = 1; break;
     case oDisableIPv4: opt.disable_ipv4 = 1; break;
     case oDisableIPv6: opt.disable_ipv6 = 1; break;
     case oHonorHTTPProxy: opt.honor_http_proxy = 1; break;
     case oHTTPProxy: opt.http_proxy = pargs->r.ret_str; break;
     case oLDAPProxy: opt.ldap_proxy = pargs->r.ret_str; break;
     case oOnlyLDAPProxy: opt.only_ldap_proxy = 1; break;
     case oIgnoreHTTPDP: opt.ignore_http_dp = 1; break;
     case oIgnoreLDAPDP: opt.ignore_ldap_dp = 1; break;
     case oIgnoreOCSPSvcUrl: opt.ignore_ocsp_service_url = 1; break;
 
     case oAllowOCSP: opt.allow_ocsp = 1; break;
     case oAllowVersionCheck: opt.allow_version_check = 1; break;
     case oOCSPResponder: opt.ocsp_responder = pargs->r.ret_str; break;
     case oOCSPSigner:
       opt.ocsp_signer = parse_fingerprint_item (pargs->r.ret_str,
                                                 "--ocsp-signer", 0);
       break;
     case oOCSPMaxClockSkew: opt.ocsp_max_clock_skew = pargs->r.ret_int; break;
     case oOCSPMaxPeriod: opt.ocsp_max_period = pargs->r.ret_int; break;
     case oOCSPCurrentPeriod: opt.ocsp_current_period = pargs->r.ret_int; break;
 
     case oMaxReplies: opt.max_replies = pargs->r.ret_int; break;
 
     case oHkpCaCert:
       {
         /* We need to register the filenames with gnutls (http.c) and
          * also for our own cert cache.  */
         char *tmpname;
 
         /* Do tilde expansion and make path absolute.  */
         tmpname = make_absfilename (pargs->r.ret_str, NULL);
         http_register_tls_ca (tmpname);
         add_to_strlist (&hkp_cacert_filenames, pargs->r.ret_str);
         xfree (tmpname);
       }
       break;
 
     case oIgnoreCert:
       {
         fingerprint_list_t item, r;
         item = parse_fingerprint_item (pargs->r.ret_str, "--ignore-cert", 20);
         if (item)
           {  /* Append  */
             if (!opt.ignored_certs)
               opt.ignored_certs = item;
             else
               {
                 for (r = opt.ignored_certs; r->next; r = r->next)
                   ;
                 r->next = item;
               }
           }
       }
       break;
 
     case oIgnoreCertExtension:
       add_to_strlist (&opt.ignored_cert_extensions, pargs->r.ret_str);
       break;
 
     case oUseTor:
       tor_mode = TOR_MODE_FORCE;
       break;
     case oNoUseTor:
       if (tor_mode != TOR_MODE_FORCE)
         tor_mode = TOR_MODE_NEVER;
       break;
 
     case oStandardResolver: enable_standard_resolver (1); break;
     case oRecursiveResolver: enable_recursive_resolver (1); break;
 
     case oLDAPServer:
 #if USE_LDAP
       {
         ldap_server_t server;
         char *p;
 
         p = pargs->r.ret_str;
         if (!strncmp (p, "ldap:", 5) && !(p[5] == '/' && p[6] == '/'))
           p += 5;
 
         server = ldapserver_parse_one (p, NULL, 0);
         if (server)
           {
             if (ldapserver_list_needs_reset)
               {
                 ldapserver_list_needs_reset = 0;
                 ldapserver_list_free (opt.ldapservers);
                 opt.ldapservers = NULL;
               }
             server->next = opt.ldapservers;
             opt.ldapservers = server;
           }
       }
 #endif
       break;
 
     case oKeyServer:
       if (*pargs->r.ret_str)
         add_to_strlist (&opt.keyserver, pargs->r.ret_str);
       break;
 
     case oNameServer:
       set_dns_nameserver (pargs->r.ret_str);
       break;
 
     case oResolverTimeout:
       set_dns_timeout (pargs->r.ret_int);
       break;
 
     case oConnectTimeout:
       opt.connect_timeout = pargs->r.ret_ulong * 1000;
       break;
 
     case oConnectQuickTimeout:
       opt.connect_quick_timeout = pargs->r.ret_ulong * 1000;
       break;
 
     case oLDAPTimeout:
       opt.ldaptimeout = pargs->r.ret_int;
       break;
 
     case oDebugCacheExpiredCerts:
       opt.debug_cache_expired_certs = 0;
       break;
 
+    case oCompatibilityFlags:
+      if (parse_compatibility_flags (pargs->r.ret_str, &opt.compat_flags,
+                                     compatibility_flags))
+        {
+          pargs->r_opt = ARGPARSE_INVALID_ARG;
+          pargs->err = ARGPARSE_PRINT_WARNING;
+        }
+      break;
+
     default:
       return 0; /* Not handled. */
     }
 
   set_dns_verbose (opt.verbose, !!DBG_DNS);
   http_set_verbose (opt.verbose, !!DBG_NETWORK);
   set_dns_disable_ipv4 (opt.disable_ipv4);
   set_dns_disable_ipv6 (opt.disable_ipv6);
 
   return 1; /* Handled. */
 }
 
 
 /* This fucntion is called after option parsing to adjust some values
  * and call option setup functions.  */
 static void
 post_option_parsing (enum cmd_and_opt_values cmd)
 {
   /* It would be too surpirsing if the quick timeout is larger than
    * the standard value.  */
   if (opt.connect_quick_timeout > opt.connect_timeout)
     opt.connect_quick_timeout = opt.connect_timeout;
 
   set_debug ();
   /* For certain commands we do not want to set/test for Tor mode
    * because that is somewhat expensive.  */
   switch (cmd)
     {
     case aGPGConfList:
     case aGPGConfTest:
     case aGPGConfVersions:
       break;
     default:
       set_tor_mode ();
       break;
     }
 }
 
 
 #ifndef HAVE_W32_SYSTEM
 static int
 pid_suffix_callback (unsigned long *r_suffix)
 {
   union int_and_ptr_u value;
 
   memset (&value, 0, sizeof value);
   value.aptr = npth_getspecific (my_tlskey_current_fd);
   *r_suffix = value.aint;
   return (*r_suffix != -1);  /* Use decimal representation.  */
 }
 #endif /*!HAVE_W32_SYSTEM*/
 
 #if HTTP_USE_NTBTLS
 static void
 my_ntbtls_log_handler (void *opaque, int level, const char *fmt, va_list argv)
 {
   (void)opaque;
 
   if (level == -1)
     log_logv_with_prefix (GPGRT_LOG_INFO, "ntbtls: ", fmt, argv);
   else
     {
       char prefix[10+20];
       snprintf (prefix, sizeof prefix, "ntbtls(%d): ", level);
       log_logv_with_prefix (GPGRT_LOG_DEBUG, prefix, fmt, argv);
     }
 }
 #endif
 
 
 static void
 thread_init (void)
 {
   npth_init ();
   assuan_set_system_hooks (ASSUAN_SYSTEM_NPTH);
   gpgrt_set_syscall_clamp (npth_unprotect, npth_protect);
 
   /* Now with NPth running we can set the logging callback.  Our
      windows implementation does not yet feature the NPth TLS
      functions.  */
 #ifndef HAVE_W32_SYSTEM
   if (npth_key_create (&my_tlskey_current_fd, NULL) == 0)
     if (npth_setspecific (my_tlskey_current_fd, NULL) == 0)
       log_set_pid_suffix_cb (pid_suffix_callback);
 #endif /*!HAVE_W32_SYSTEM*/
 }
 
 
 int
 main (int argc, char **argv)
 {
   enum cmd_and_opt_values cmd = 0;
   ARGPARSE_ARGS pargs;
   int orig_argc;
   char **orig_argv;
   char *last_configname = NULL;
   const char *configname = NULL;
   const char *shell;
   int debug_argparser = 0;
   int greeting = 0;
   int nogreeting = 0;
   int nodetach = 0;
   int csh_style = 0;
   char *logfile = NULL;
 #if USE_LDAP
   char *ldapfile = NULL;
 #endif /*USE_LDAP*/
   int debug_wait = 0;
   int rc;
   struct assuan_malloc_hooks malloc_hooks;
 
   early_system_init ();
   set_strusage (my_strusage);
   log_set_prefix (DIRMNGR_NAME, GPGRT_LOG_WITH_PREFIX | GPGRT_LOG_WITH_PID);
 
   /* Make sure that our subsystems are ready.  */
   i18n_init ();
   init_common_subsystems (&argc, &argv);
 
   gcry_control (GCRYCTL_DISABLE_SECMEM, 0);
 
  /* Check that the libraries are suitable.  Do it here because
     the option parsing may need services of the libraries. */
   if (!ksba_check_version (NEED_KSBA_VERSION) )
     log_fatal( _("%s is too old (need %s, have %s)\n"), "libksba",
                NEED_KSBA_VERSION, ksba_check_version (NULL) );
 
   ksba_set_malloc_hooks (gcry_malloc, gcry_realloc, gcry_free );
   ksba_set_hash_buffer_function (my_ksba_hash_buffer, NULL);
 
   /* Init TLS library.  */
 #if HTTP_USE_NTBTLS
   if (!ntbtls_check_version (NEED_NTBTLS_VERSION) )
     log_fatal( _("%s is too old (need %s, have %s)\n"), "ntbtls",
                NEED_NTBTLS_VERSION, ntbtls_check_version (NULL) );
 #elif HTTP_USE_GNUTLS
   rc = gnutls_global_init ();
   if (rc)
     log_fatal ("gnutls_global_init failed: %s\n", gnutls_strerror (rc));
 #endif /*HTTP_USE_GNUTLS*/
 
   /* Init Assuan. */
   malloc_hooks.malloc = gcry_malloc;
   malloc_hooks.realloc = gcry_realloc;
   malloc_hooks.free = gcry_free;
   assuan_set_malloc_hooks (&malloc_hooks);
   assuan_set_assuan_log_prefix (log_get_prefix (NULL));
   assuan_set_gpg_err_source (GPG_ERR_SOURCE_DEFAULT);
   assuan_sock_init ();
   setup_libassuan_logging (&opt.debug, dirmngr_assuan_log_monitor);
 
   setup_libgcrypt_logging ();
 
 #if HTTP_USE_NTBTLS
   ntbtls_set_log_handler (my_ntbtls_log_handler, NULL);
 #endif
 
   /* Setup defaults. */
   shell = getenv ("SHELL");
   if (shell && strlen (shell) >= 3 && !strcmp (shell+strlen (shell)-3, "csh") )
     csh_style = 1;
 
   /* Reset rereadable options to default values. */
   parse_rereadable_options (NULL, 0);
 
   /* Default TCP timeouts.  */
   opt.connect_timeout = DEFAULT_CONNECT_TIMEOUT;
   opt.connect_quick_timeout = DEFAULT_CONNECT_QUICK_TIMEOUT;
 
   /* LDAP defaults.  */
   opt.add_new_ldapservers = 0;
   opt.ldaptimeout = DEFAULT_LDAP_TIMEOUT;
 
   /* Other defaults.  */
 
   /* Check whether we have a config file given on the commandline */
   orig_argc = argc;
   orig_argv = argv;
   pargs.argc = &argc;
   pargs.argv = &argv;
   pargs.flags= (ARGPARSE_FLAG_KEEP | ARGPARSE_FLAG_NOVERSION);
   while (gnupg_argparse (NULL, &pargs, opts))
     {
       switch (pargs.r_opt)
         {
         case oDebug:
         case oDebugAll:
           debug_argparser++;
           break;
         case oHomedir:
           gnupg_set_homedir (pargs.r.ret_str);
           break;
         }
     }
   /* Reset the flags.  */
   pargs.flags &= ~(ARGPARSE_FLAG_KEEP | ARGPARSE_FLAG_NOVERSION);
 
   socket_name = dirmngr_socket_name ();
 
   /* The configuraton directories for use by gpgrt_argparser.  */
   gnupg_set_confdir (GNUPG_CONFDIR_SYS, gnupg_sysconfdir ());
   gnupg_set_confdir (GNUPG_CONFDIR_USER, gnupg_homedir ());
 
   /* We are re-using the struct, thus the reset flag.  We OR the
    * flags so that the internal intialized flag won't be cleared. */
   argc = orig_argc;
   argv = orig_argv;
   pargs.argc = &argc;
   pargs.argv = &argv;
   pargs.flags |=  (ARGPARSE_FLAG_RESET
                    | ARGPARSE_FLAG_KEEP
                    | ARGPARSE_FLAG_SYS
                    | ARGPARSE_FLAG_USER);
   while (gnupg_argparser (&pargs, opts, DIRMNGR_NAME EXTSEP_S "conf"))
     {
       if (pargs.r_opt == ARGPARSE_CONFFILE)
         {
           if (debug_argparser)
             log_info (_("reading options from '%s'\n"),
                       pargs.r_type? pargs.r.ret_str: "[cmdline]");
           if (pargs.r_type)
             {
               xfree (last_configname);
               last_configname = xstrdup (pargs.r.ret_str);
               configname = last_configname;
             }
           else
             configname = NULL;
           continue;
         }
       if (parse_rereadable_options (&pargs, 0))
         continue; /* Already handled */
       switch (pargs.r_opt)
         {
         case aServer:
         case aDaemon:
         case aSupervised:
         case aShutdown:
         case aFlush:
 	case aListCRLs:
 	case aLoadCRL:
         case aFetchCRL:
 	case aGPGConfList:
 	case aGPGConfTest:
 	case aGPGConfVersions:
           cmd = pargs.r_opt;
           break;
 
         case oQuiet: opt.quiet = 1; break;
         case oVerbose: opt.verbose++; break;
         case oBatch: opt.batch=1; break;
 
         case oDebugWait: debug_wait = pargs.r.ret_int; break;
 
         case oNoGreeting: nogreeting = 1; break;
         case oNoVerbose: opt.verbose = 0; break;
         case oHomedir: /* Ignore this option here. */; break;
         case oNoDetach: nodetach = 1; break;
         case oStealSocket: steal_socket = 1; break;
         case oLogFile: logfile = pargs.r.ret_str; break;
         case oCsh: csh_style = 1; break;
         case oSh: csh_style = 0; break;
 	case oLDAPFile:
 #        if USE_LDAP
           ldapfile = pargs.r.ret_str;
 #        endif /*USE_LDAP*/
           break;
 	case oLDAPAddServers: opt.add_new_ldapservers = 1; break;
 
         case oFakedSystemTime:
           gnupg_set_time ((time_t)pargs.r.ret_ulong, 0);
           break;
 
         case oForce: opt.force = 1; break;
 
         case oSocketName: socket_name = pargs.r.ret_str; break;
 
         case oListenBacklog:
           listen_backlog = pargs.r.ret_int;
           break;
 
         default:
           if (configname)
             pargs.err = ARGPARSE_PRINT_WARNING;
           else
             pargs.err = ARGPARSE_PRINT_ERROR;
           break;
 	}
     }
   gnupg_argparse (NULL, &pargs, NULL);  /* Release internal state.  */
 
   if (!last_configname)
     opt.config_filename = make_filename (gnupg_homedir (),
                                          DIRMNGR_NAME EXTSEP_S "conf",
                                          NULL);
   else
     {
       opt.config_filename = last_configname;
       last_configname = NULL;
     }
 
   if (log_get_errorcount(0))
     exit(2);
   if (nogreeting )
     greeting = 0;
 
   if (!opt.homedir_cache)
     opt.homedir_cache = xstrdup (gnupg_homedir ());
 
   if (greeting)
     {
       es_fprintf (es_stderr, "%s %s; %s\n",
                   strusage(11), strusage(13), strusage(14) );
       es_fprintf (es_stderr, "%s\n", strusage(15) );
     }
 
 #ifdef IS_DEVELOPMENT_VERSION
   log_info ("NOTE: this is a development version!\n");
 #endif
 
   /* Print a warning if an argument looks like an option.  */
   if (!opt.quiet && !(pargs.flags & ARGPARSE_FLAG_STOP_SEEN))
     {
       int i;
 
       for (i=0; i < argc; i++)
         if (argv[i][0] == '-' && argv[i][1] == '-')
           log_info (_("Note: '%s' is not considered an option\n"), argv[i]);
     }
 
   if (!gnupg_access ("/etc/"DIRMNGR_NAME, F_OK)
       && !strncmp (gnupg_homedir (), "/etc/", 5))
     log_info
       ("NOTE: DirMngr is now a proper part of %s.  The configuration and"
        " other directory names changed.  Please check that no other version"
        " of dirmngr is still installed.  To disable this warning, remove the"
        " directory '/etc/dirmngr'.\n", GNUPG_NAME);
 
   if (gnupg_faked_time_p ())
     {
       gnupg_isotime_t tbuf;
 
       log_info (_("WARNING: running with faked system time: "));
       gnupg_get_isotime (tbuf);
       dump_isotime (tbuf);
       log_printf ("\n");
     }
 
   post_option_parsing (cmd);
 
   /* Get LDAP server list from file unless --ldapserver has been used.  */
 #if USE_LDAP
   if (opt.ldapservers)
     ;
   else if (!ldapfile)
     {
       ldapfile = make_filename (gnupg_homedir (),
                                 "dirmngr_ldapservers.conf",
                                 NULL);
       opt.ldapservers = parse_ldapserver_file (ldapfile, 1);
       xfree (ldapfile);
     }
   else
     opt.ldapservers = parse_ldapserver_file (ldapfile, 0);
 #endif /*USE_LDAP*/
 
 #ifndef HAVE_W32_SYSTEM
   /* We need to ignore the PIPE signal because the we might log to a
      socket and that code handles EPIPE properly.  The ldap wrapper
      also requires us to ignore this silly signal. Assuan would set
      this signal to ignore anyway.*/
   signal (SIGPIPE, SIG_IGN);
 #endif
 
   /* Ready.  Now to our duties. */
   if (!cmd)
     cmd = aServer;
   rc = 0;
 
   if (cmd == aServer)
     {
       /* Note that this server mode is mainly useful for debugging.  */
       if (argc)
         wrong_args ("--server");
 
       if (logfile)
         {
           log_set_file (logfile);
           log_set_prefix (NULL, GPGRT_LOG_WITH_TIME | GPGRT_LOG_WITH_PID);
         }
 
       if (debug_wait)
         {
           log_debug ("waiting for debugger - my pid is %u .....\n",
                      (unsigned int)getpid());
           gnupg_sleep (debug_wait);
           log_debug ("... okay\n");
         }
 
 
       thread_init ();
       cert_cache_init (hkp_cacert_filenames);
       crl_cache_init ();
       http_register_netactivity_cb (netactivity_action);
       start_command_handler (ASSUAN_INVALID_FD, 0);
       shutdown_reaper ();
     }
 #ifndef HAVE_W32_SYSTEM
   else if (cmd == aSupervised)
     {
       /* In supervised mode, we expect file descriptor 3 to be an
          already opened, listening socket.
 
          We will also not detach from the controlling process or close
          stderr; the supervisor should handle all of that.  */
       struct stat statbuf;
       if (fstat (3, &statbuf) == -1 && errno == EBADF)
         {
           log_error ("file descriptor 3 must be validin --supervised mode\n");
           dirmngr_exit (1);
         }
       socket_name = gnupg_get_socket_name (3);
 
       /* Now start with logging to a file if this is desired. */
       if (logfile)
         {
           log_set_file (logfile);
           log_set_prefix (NULL, (GPGRT_LOG_WITH_PREFIX
                                  |GPGRT_LOG_WITH_TIME
                                  |GPGRT_LOG_WITH_PID));
           current_logfile = xstrdup (logfile);
         }
       else
         log_set_prefix (NULL, 0);
 
       thread_init ();
       cert_cache_init (hkp_cacert_filenames);
       crl_cache_init ();
       http_register_netactivity_cb (netactivity_action);
       handle_connections (3);
       shutdown_reaper ();
     }
 #endif /*HAVE_W32_SYSTEM*/
   else if (cmd == aDaemon)
     {
       assuan_fd_t fd;
       pid_t pid;
       int len;
       struct sockaddr_un serv_addr;
 
       if (argc)
         wrong_args ("--daemon");
 
       /* Now start with logging to a file if this is desired. */
       if (logfile)
         {
           log_set_file (logfile);
           log_set_prefix (NULL, (GPGRT_LOG_WITH_PREFIX
                                  |GPGRT_LOG_WITH_TIME
                                  |GPGRT_LOG_WITH_PID));
           current_logfile = xstrdup (logfile);
         }
 
       if (debug_wait)
         {
           log_debug ("waiting for debugger - my pid is %u .....\n",
                      (unsigned int)getpid());
           gnupg_sleep (debug_wait);
           log_debug ("... okay\n");
         }
 
 #ifndef HAVE_W32_SYSTEM
       if (strchr (socket_name, ':'))
         {
           log_error (_("colons are not allowed in the socket name\n"));
           dirmngr_exit (1);
         }
 #endif
       fd = assuan_sock_new (AF_UNIX, SOCK_STREAM, 0);
       if (fd == ASSUAN_INVALID_FD)
         {
           log_error (_("can't create socket: %s\n"), strerror (errno));
           cleanup ();
           dirmngr_exit (1);
         }
 
       {
         int redirected;
 
         if (assuan_sock_set_sockaddr_un (socket_name,
                                          (struct sockaddr*)&serv_addr,
                                          &redirected))
           {
             if (errno == ENAMETOOLONG)
               log_error (_("socket name '%s' is too long\n"), socket_name);
             else
               log_error ("error preparing socket '%s': %s\n",
                          socket_name,
                          gpg_strerror (gpg_error_from_syserror ()));
             dirmngr_exit (1);
           }
         if (redirected)
           {
             redir_socket_name = xstrdup (serv_addr.sun_path);
             if (opt.verbose)
               log_info ("redirecting socket '%s' to '%s'\n",
                         socket_name, redir_socket_name);
           }
       }
 
       len = SUN_LEN (&serv_addr);
 
       rc = assuan_sock_bind (fd, (struct sockaddr*) &serv_addr, len);
       if (rc == -1
           && (errno == EADDRINUSE
 #ifdef HAVE_W32_SYSTEM
               || errno == EEXIST
 #endif
               ))
 	{
           /* Fixme: We should actually test whether a dirmngr is
            * already running.  For now the steal option is a dummy. */
           /* if (steal_socket) */
           /*   log_info (N_("trying to steal socket from running %s\n"), */
           /*             "dirmngr"); */
 	  gnupg_remove (redir_socket_name? redir_socket_name : socket_name);
 	  rc = assuan_sock_bind (fd, (struct sockaddr*) &serv_addr, len);
 	}
       if (rc != -1
 	  && (rc = assuan_sock_get_nonce ((struct sockaddr*) &serv_addr, len, &socket_nonce)))
 	log_error (_("error getting nonce for the socket\n"));
       if (rc == -1)
         {
           log_error (_("error binding socket to '%s': %s\n"),
                      serv_addr.sun_path,
                      gpg_strerror (gpg_error_from_syserror ()));
           assuan_sock_close (fd);
           dirmngr_exit (1);
         }
       cleanup_socket = 1;
 
       if (gnupg_chmod (serv_addr.sun_path, "-rwx"))
         log_error (_("can't set permissions of '%s': %s\n"),
                    serv_addr.sun_path, strerror (errno));
 
       if (listen (FD2INT (fd), listen_backlog) == -1)
         {
           log_error ("listen(fd,%d) failed: %s\n",
                      listen_backlog, strerror (errno));
           assuan_sock_close (fd);
           dirmngr_exit (1);
         }
 
       if (opt.verbose)
         log_info (_("listening on socket '%s'\n"), serv_addr.sun_path);
 
       es_fflush (NULL);
 
       /* Note: We keep the dirmngr_info output only for the sake of
          existing scripts which might use this to detect a successful
          start of the dirmngr.  */
 #ifdef HAVE_W32_SYSTEM
       (void)csh_style;
       (void)nodetach;
 
       pid = getpid ();
       es_printf ("set %s=%s;%lu;1\n",
                  DIRMNGR_INFO_NAME, socket_name, (ulong) pid);
 #else
       pid = fork();
       if (pid == (pid_t)-1)
         {
           log_fatal (_("error forking process: %s\n"), strerror (errno));
           dirmngr_exit (1);
         }
 
       if (pid)
         { /* We are the parent */
           char *infostr;
 
           /* Don't let cleanup() remove the socket - the child is
              responsible for doing that.  */
           cleanup_socket = 0;
 
           close (fd);
 
           /* Create the info string: <name>:<pid>:<protocol_version> */
           if (asprintf (&infostr, "%s=%s:%lu:1",
                         DIRMNGR_INFO_NAME, serv_addr.sun_path, (ulong)pid ) < 0)
             {
               log_error (_("out of core\n"));
               kill (pid, SIGTERM);
               dirmngr_exit (1);
             }
           /* Print the environment string, so that the caller can use
              shell's eval to set it.  But see above.  */
           if (csh_style)
             {
               *strchr (infostr, '=') = ' ';
               es_printf ( "setenv %s;\n", infostr);
             }
           else
             {
               es_printf ( "%s; export %s;\n", infostr, DIRMNGR_INFO_NAME);
             }
           free (infostr);
           exit (0);
           /*NEVER REACHED*/
         } /* end parent */
 
 
       /*
          This is the child
        */
 
       /* Detach from tty and put process into a new session */
       if (!nodetach )
         {
           int i;
           unsigned int oldflags;
 
           /* Close stdin, stdout and stderr unless it is the log stream */
           for (i=0; i <= 2; i++)
             {
               if (!log_test_fd (i) && i != fd )
                 {
                   if ( !close (i)
                        && open ("/dev/null", i? O_WRONLY : O_RDONLY) == -1)
                     {
                       log_error ("failed to open '%s': %s\n",
                                  "/dev/null", strerror (errno));
                       cleanup ();
                       dirmngr_exit (1);
                     }
                 }
             }
 
           if (setsid() == -1)
             {
               log_error ("setsid() failed: %s\n", strerror(errno) );
               dirmngr_exit (1);
             }
 
           log_get_prefix (&oldflags);
           log_set_prefix (NULL, oldflags | GPGRT_LOG_RUN_DETACHED);
           opt.running_detached = 1;
 
         }
 #endif
 
       if (!nodetach )
         {
           if (gnupg_chdir (gnupg_daemon_rootdir ()))
             {
               log_error ("chdir to '%s' failed: %s\n",
                          gnupg_daemon_rootdir (), strerror (errno));
               dirmngr_exit (1);
             }
         }
 
       thread_init ();
       cert_cache_init (hkp_cacert_filenames);
       crl_cache_init ();
       http_register_netactivity_cb (netactivity_action);
       handle_connections (fd);
       shutdown_reaper ();
     }
   else if (cmd == aListCRLs)
     {
       /* Just list the CRL cache and exit. */
       if (argc)
         wrong_args ("--list-crls");
       crl_cache_init ();
       crl_cache_list (es_stdout);
     }
   else if (cmd == aLoadCRL)
     {
       struct server_control_s ctrlbuf;
 
       memset (&ctrlbuf, 0, sizeof ctrlbuf);
       dirmngr_init_default_ctrl (&ctrlbuf);
 
       thread_init ();
       cert_cache_init (hkp_cacert_filenames);
       crl_cache_init ();
       if (!argc)
         rc = crl_cache_load (&ctrlbuf, NULL);
       else
         {
           for (; !rc && argc; argc--, argv++)
             rc = crl_cache_load (&ctrlbuf, *argv);
         }
       dirmngr_deinit_default_ctrl (&ctrlbuf);
     }
   else if (cmd == aFetchCRL)
     {
       ksba_reader_t reader;
       struct server_control_s ctrlbuf;
 
       if (argc != 1)
         wrong_args ("--fetch-crl URL");
 
       memset (&ctrlbuf, 0, sizeof ctrlbuf);
       dirmngr_init_default_ctrl (&ctrlbuf);
 
       thread_init ();
       cert_cache_init (hkp_cacert_filenames);
       crl_cache_init ();
       rc = crl_fetch (&ctrlbuf, argv[0], &reader);
       if (rc)
         log_error (_("fetching CRL from '%s' failed: %s\n"),
                      argv[0], gpg_strerror (rc));
       else
         {
           rc = crl_cache_insert (&ctrlbuf, argv[0], reader);
           if (rc)
             log_error (_("processing CRL from '%s' failed: %s\n"),
                        argv[0], gpg_strerror (rc));
           crl_close_reader (reader);
         }
       dirmngr_deinit_default_ctrl (&ctrlbuf);
     }
   else if (cmd == aFlush)
     {
       /* Delete cache and exit. */
       if (argc)
         wrong_args ("--flush");
       rc = crl_cache_flush();
     }
   else if (cmd == aGPGConfTest)
     dirmngr_exit (0);
   else if (cmd == aGPGConfList)
     {
       unsigned long flags = 0;
       char *filename_esc;
 
       es_printf ("debug-level:%lu:\"none\n", flags | GC_OPT_FLAG_DEFAULT);
       es_printf ("ldaptimeout:%lu:%u\n",
                  flags | GC_OPT_FLAG_DEFAULT, DEFAULT_LDAP_TIMEOUT);
       es_printf ("max-replies:%lu:%u\n",
                  flags | GC_OPT_FLAG_DEFAULT, DEFAULT_MAX_REPLIES);
 
       filename_esc = percent_escape (get_default_keyserver (0), NULL);
       es_printf ("keyserver:%lu:\"%s:\n", flags | GC_OPT_FLAG_DEFAULT,
                  filename_esc);
       xfree (filename_esc);
 
       es_printf ("resolver-timeout:%lu:%u\n",
                  flags | GC_OPT_FLAG_DEFAULT, 0);
     }
   else if (cmd == aGPGConfVersions)
     gpgconf_versions ();
 
   cleanup ();
   return !!rc;
 }
 
 
 static void
 cleanup (void)
 {
   crl_cache_deinit ();
   cert_cache_deinit (1);
   reload_dns_stuff (1);
 
 #if USE_LDAP
   ldapserver_list_free (opt.ldapservers);
 #endif /*USE_LDAP*/
   opt.ldapservers = NULL;
 
   if (cleanup_socket)
     {
       cleanup_socket = 0;
       if (redir_socket_name)
         gnupg_remove (redir_socket_name);
       else if (socket_name && *socket_name)
         gnupg_remove (socket_name);
     }
 }
 
 
 void
 dirmngr_exit (int rc)
 {
   cleanup ();
   exit (rc);
 }
 
 
 void
 dirmngr_init_default_ctrl (ctrl_t ctrl)
 {
   ctrl->magic = SERVER_CONTROL_MAGIC;
   if (opt.http_proxy)
     ctrl->http_proxy = xstrdup (opt.http_proxy);
   ctrl->http_no_crl = 1;
   ctrl->timeout = opt.connect_timeout;
 }
 
 
 void
 dirmngr_deinit_default_ctrl (ctrl_t ctrl)
 {
   if (!ctrl)
     return;
   ctrl->magic = 0xdeadbeef;
 
   xfree (ctrl->http_proxy);
   ctrl->http_proxy = NULL;
 }
 
 
 /* Create a list of LDAP servers from the file FILENAME. Returns the
    list or NULL in case of errors.
 
    The format fo such a file is line oriented where empty lines and
    lines starting with a hash mark are ignored.  All other lines are
    assumed to be colon seprated with these fields:
 
    1. field: Hostname
    2. field: Portnumber
    3. field: Username
    4. field: Password
    5. field: Base DN
 
 */
 #if USE_LDAP
 static ldap_server_t
 parse_ldapserver_file (const char* filename, int ignore_enoent)
 {
   char buffer[1024];
   char *p;
   ldap_server_t server, serverstart, *serverend;
   int c;
   unsigned int lineno = 0;
   estream_t fp;
 
   fp = es_fopen (filename, "r");
   if (!fp)
     {
       if (errno == ENOENT)
         {
           if (!ignore_enoent)
             log_info ("No ldapserver file at: '%s'\n", filename);
         }
       else
         log_error (_("error opening '%s': %s\n"), filename,
                    strerror (errno));
       return NULL;
     }
 
   serverstart = NULL;
   serverend = &serverstart;
   while (es_fgets (buffer, sizeof buffer, fp))
     {
       lineno++;
       if (!*buffer || buffer[strlen(buffer)-1] != '\n')
         {
           if (*buffer && es_feof (fp))
             ; /* Last line not terminated - continue. */
           else
             {
               log_error (_("%s:%u: line too long - skipped\n"),
                          filename, lineno);
               while ( (c=es_fgetc (fp)) != EOF && c != '\n')
                 ; /* Skip until end of line. */
               continue;
             }
         }
       /* Skip empty and comment lines.*/
       for (p=buffer; spacep (p); p++)
         ;
       if (!*p || *p == '\n' || *p == '#')
         continue;
 
       /* Parse the colon separated fields. */
       server = ldapserver_parse_one (buffer, filename, lineno);
       if (server)
         {
           *serverend = server;
           serverend = &server->next;
         }
     }
 
   if (es_ferror (fp))
     log_error (_("error reading '%s': %s\n"), filename, strerror (errno));
   es_fclose (fp);
 
   return serverstart;
 }
 #endif /*USE_LDAP*/
 
 
 /* Parse a fingerprint entry as used by --ocsc-signer.  OPTIONNAME as
  * a description on the options used.  WANT_BINARY requests to store a
  * binary fingerprint.  Returns NULL on error and logs that error. */
 static fingerprint_list_t
 parse_fingerprint_item (const char *string,
                         const char *optionname, int want_binary)
 {
   gpg_error_t err;
   char *fname;
   estream_t fp;
   char line[256];
   char *p;
   fingerprint_list_t list, *list_tail, item;
   unsigned int lnr = 0;
   int c, i, j;
   int errflag = 0;
 
 
   /* Check whether this is not a filename and treat it as a direct
      fingerprint specification.  */
   if (!strpbrk (string, "/.~\\"))
     {
       item = xcalloc (1, sizeof *item);
       for (i=j=0; (string[i] == ':' || hexdigitp (string+i)) && j < 40; i++)
         if ( string[i] != ':' )
           item->hexfpr[j++] = string[i] >= 'a'? (string[i] & 0xdf): string[i];
       item->hexfpr[j] = 0;
       if (j != 40 || !(spacep (string+i) || !string[i]))
         {
           log_error (_("%s:%u: invalid fingerprint detected\n"),
                      optionname, 0);
           xfree (item);
           return NULL;
         }
       if (want_binary)
         {
           item->binlen = 20;
           hex2bin (item->hexfpr, item->hexfpr, 20);
         }
       return item;
     }
 
   /* Well, it is a filename.  */
   if (*string == '/' || (*string == '~' && string[1] == '/'))
     fname = make_filename (string, NULL);
   else
     {
       if (string[0] == '.' && string[1] == '/' )
         string += 2;
       fname = make_filename (gnupg_homedir (), string, NULL);
     }
 
   fp = es_fopen (fname, "r");
   if (!fp)
     {
       err = gpg_error_from_syserror ();
       log_error (_("can't open '%s': %s\n"), fname, gpg_strerror (err));
       xfree (fname);
       return NULL;
     }
 
   list = NULL;
   list_tail = &list;
   for (;;)
     {
       if (!es_fgets (line, DIM(line)-1, fp) )
         {
           if (!es_feof (fp))
             {
               err = gpg_error_from_syserror ();
               log_error (_("%s:%u: read error: %s\n"),
                          fname, lnr, gpg_strerror (err));
               errflag = 1;
             }
           es_fclose (fp);
           if (errflag)
             {
               while (list)
                 {
                   fingerprint_list_t tmp = list->next;
                   xfree (list);
                   list = tmp;
                 }
             }
           xfree (fname);
           return list; /* Ready.  */
         }
 
       lnr++;
       if (!*line || line[strlen(line)-1] != '\n')
         {
           /* Eat until end of line. */
           while ( (c=es_getc (fp)) != EOF && c != '\n')
             ;
           err = gpg_error (*line? GPG_ERR_LINE_TOO_LONG
                            /* */: GPG_ERR_INCOMPLETE_LINE);
           log_error (_("%s:%u: read error: %s\n"),
                      fname, lnr, gpg_strerror (err));
           errflag = 1;
           continue;
         }
 
       /* Allow for empty lines and spaces */
       for (p=line; spacep (p); p++)
         ;
       if (!*p || *p == '\n' || *p == '#')
         continue;
 
       item = xcalloc (1, sizeof *item);
       *list_tail = item;
       list_tail = &item->next;
 
       for (i=j=0; (p[i] == ':' || hexdigitp (p+i)) && j < 40; i++)
         if ( p[i] != ':' )
           item->hexfpr[j++] = p[i] >= 'a'? (p[i] & 0xdf): p[i];
       item->hexfpr[j] = 0;
       if (j != 40 || !(spacep (p+i) || p[i] == '\n'))
         {
           log_error (_("%s:%u: invalid fingerprint detected\n"), fname, lnr);
           errflag = 1;
         }
       else if (want_binary)
         {
           item->binlen = 20;
           hex2bin (item->hexfpr, item->hexfpr, 20);
         }
 
       i++;
       while (spacep (p+i))
         i++;
       if (p[i] && p[i] != '\n')
         log_info (_("%s:%u: garbage at end of line ignored\n"), fname, lnr);
     }
   /*NOTREACHED*/
 }
 
 
 
 
 /*
    Stuff used in daemon mode.
  */
 
 
 
 /* Reread parts of the configuration.  Note, that this function is
    obviously not thread-safe and should only be called from the NPTH
    signal handler.
 
    Fixme: Due to the way the argument parsing works, we create a
    memory leak here for all string type arguments.  There is currently
    no clean way to tell whether the memory for the argument has been
    allocated or points into the process' original arguments.  Unless
    we have a mechanism to tell this, we need to live on with this. */
 static void
 reread_configuration (void)
 {
   ARGPARSE_ARGS pargs;
   char *twopart;
   int dummy;
 
   if (!opt.config_filename)
     return; /* No config file. */
 
   twopart = strconcat (DIRMNGR_NAME EXTSEP_S "conf" PATHSEP_S,
                        opt.config_filename, NULL);
   if (!twopart)
     return;  /* Out of core.  */
 
   parse_rereadable_options (NULL, 1); /* Start from the default values. */
 
   memset (&pargs, 0, sizeof pargs);
   dummy = 0;
   pargs.argc = &dummy;
   pargs.flags = (ARGPARSE_FLAG_KEEP
                  |ARGPARSE_FLAG_SYS
                  |ARGPARSE_FLAG_USER);
   while (gnupg_argparser (&pargs, opts, twopart))
     {
       if (pargs.r_opt == ARGPARSE_CONFFILE)
         {
           log_info (_("reading options from '%s'\n"),
                     pargs.r_type? pargs.r.ret_str: "[cmdline]");
         }
       else if (pargs.r_opt < -1)
         pargs.err = ARGPARSE_PRINT_WARNING;
       else /* Try to parse this option - ignore unchangeable ones. */
         parse_rereadable_options (&pargs, 1);
     }
   gnupg_argparse (NULL, &pargs, NULL);  /* Release internal state.  */
   xfree (twopart);
   post_option_parsing (0);
 }
 
 
 /* A global function which allows us to trigger the reload stuff from
    other places.  */
 void
 dirmngr_sighup_action (void)
 {
   log_info (_("SIGHUP received - "
               "re-reading configuration and flushing caches\n"));
   reread_configuration ();
   cert_cache_deinit (0);
   crl_cache_deinit ();
   cert_cache_init (hkp_cacert_filenames);
   crl_cache_init ();
   reload_dns_stuff (0);
   ks_hkp_reload ();
 }
 
 
 /* This function is called if some network activity was done.  At this
  * point we know the we have a network and we can decide whether to
  * run scheduled background tasks soon.  The function should return
  * quickly and only trigger actions for another thread. */
 static void
 netactivity_action (void)
 {
   network_activity_seen = 1;
 }
 
 
 /* The signal handler. */
 #ifndef HAVE_W32_SYSTEM
 static void
 handle_signal (int signo)
 {
   switch (signo)
     {
     case SIGHUP:
       dirmngr_sighup_action ();
       break;
 
     case SIGUSR1:
       cert_cache_print_stats ();
       domaininfo_print_stats ();
       break;
 
     case SIGUSR2:
       log_info (_("SIGUSR2 received - no action defined\n"));
       break;
 
     case SIGTERM:
       if (!shutdown_pending)
         log_info (_("SIGTERM received - shutting down ...\n"));
       else
         log_info (_("SIGTERM received - still %d active connections\n"),
                   active_connections);
       shutdown_pending++;
       if (shutdown_pending > 2)
         {
           log_info (_("shutdown forced\n"));
           log_info ("%s %s stopped\n", strusage(11), strusage(13) );
           cleanup ();
           dirmngr_exit (0);
 	}
       break;
 
     case SIGINT:
       log_info (_("SIGINT received - immediate shutdown\n"));
       log_info( "%s %s stopped\n", strusage(11), strusage(13));
       cleanup ();
       dirmngr_exit (0);
       break;
 
     default:
       log_info (_("signal %d received - no action defined\n"), signo);
     }
 }
 #endif /*!HAVE_W32_SYSTEM*/
 
 
 /* Thread to do the housekeeping.  */
 static void *
 housekeeping_thread (void *arg)
 {
   static int sentinel;
   time_t curtime;
   struct server_control_s ctrlbuf;
 
   (void)arg;
 
   curtime = gnupg_get_time ();
   if (sentinel)
     {
       log_info ("housekeeping is already going on\n");
       return NULL;
     }
   sentinel++;
   if (opt.verbose > 1)
     log_info ("starting housekeeping\n");
 
   memset (&ctrlbuf, 0, sizeof ctrlbuf);
   dirmngr_init_default_ctrl (&ctrlbuf);
 
   dns_stuff_housekeeping ();
   ks_hkp_housekeeping (curtime);
   if (network_activity_seen)
     {
       network_activity_seen = 0;
       if (opt.allow_version_check)
         dirmngr_load_swdb (&ctrlbuf, 0);
       workqueue_run_global_tasks (&ctrlbuf, 1);
     }
   else
     workqueue_run_global_tasks (&ctrlbuf, 0);
 
   dirmngr_deinit_default_ctrl (&ctrlbuf);
 
   if (opt.verbose > 1)
     log_info ("ready with housekeeping\n");
   sentinel--;
   return NULL;
 
 }
 
 
 #if GPGRT_GCC_HAVE_PUSH_PRAGMA
 # pragma GCC push_options
 # pragma GCC optimize ("no-strict-overflow")
 #endif
 static int
 time_for_housekeeping_p (time_t curtime)
 {
   static time_t last_housekeeping;
 
   if (!last_housekeeping)
     last_housekeeping = curtime;
 
   if (last_housekeeping + HOUSEKEEPING_INTERVAL <= curtime
       || last_housekeeping > curtime /*(be prepared for y2038)*/)
     {
       last_housekeeping = curtime;
       return 1;
     }
   return 0;
 }
 #if GPGRT_GCC_HAVE_PUSH_PRAGMA
 # pragma GCC pop_options
 #endif
 
 
 /* This is the worker for the ticker.  It is called every few seconds
    and may only do fast operations. */
 static void
 handle_tick (void)
 {
   struct stat statbuf;
 
   if (time_for_housekeeping_p (gnupg_get_time ()))
     {
       npth_t thread;
       npth_attr_t tattr;
       int err;
 
       err = npth_attr_init (&tattr);
       if (err)
         log_error ("error preparing housekeeping thread: %s\n", strerror (err));
       else
         {
           npth_attr_setdetachstate (&tattr, NPTH_CREATE_DETACHED);
           err = npth_create (&thread, &tattr, housekeeping_thread, NULL);
           if (err)
             log_error ("error spawning housekeeping thread: %s\n",
                        strerror (err));
           npth_attr_destroy (&tattr);
         }
     }
 
   /* Check whether the homedir is still available.  */
   if (!shutdown_pending
       && gnupg_stat (gnupg_homedir (), &statbuf) && errno == ENOENT)
     {
       shutdown_pending = 1;
       log_info ("homedir has been removed - shutting down\n");
     }
 }
 
 
 /* Check the nonce on a new connection.  This is a NOP unless we are
    using our Unix domain socket emulation under Windows.  */
 static int
 check_nonce (assuan_fd_t fd, assuan_sock_nonce_t *nonce)
 {
   if (assuan_sock_check_nonce (fd, nonce))
     {
       log_info (_("error reading nonce on fd %d: %s\n"),
                 FD2INT (fd), strerror (errno));
       assuan_sock_close (fd);
       return -1;
     }
   else
     return 0;
 }
 
 
 /* Helper to call a connection's main function. */
 static void *
 start_connection_thread (void *arg)
 {
   static unsigned int last_session_id;
   unsigned int session_id;
   union int_and_ptr_u argval;
   gnupg_fd_t fd;
 
   memset (&argval, 0, sizeof argval);
   argval.aptr = arg;
   fd = argval.afd;
 
   if (check_nonce (fd, &socket_nonce))
     {
       log_error ("handler nonce check FAILED\n");
       return NULL;
     }
 
 #ifndef HAVE_W32_SYSTEM
   npth_setspecific (my_tlskey_current_fd, argval.aptr);
 #endif
 
   active_connections++;
   if (opt.verbose)
     log_info (_("handler for fd %d started\n"), FD2INT (fd));
 
   session_id = ++last_session_id;
   if (!session_id)
     session_id = ++last_session_id;
   start_command_handler (fd, session_id);
 
   if (opt.verbose)
     log_info (_("handler for fd %d terminated\n"), FD2INT (fd));
   active_connections--;
 
   workqueue_run_post_session_tasks (session_id);
 
 #ifndef HAVE_W32_SYSTEM
   argval.afd = ASSUAN_INVALID_FD;
   npth_setspecific (my_tlskey_current_fd, argval.aptr);
 #endif
 
   return NULL;
 }
 
 
 #ifdef HAVE_INOTIFY_INIT
 /* Read an inotify event and return true if it matches NAME.  */
 static int
 my_inotify_is_name (int fd, const char *name)
 {
   union {
     struct inotify_event ev;
     char _buf[sizeof (struct inotify_event) + 100 + 1];
   } buf;
   int n;
   const char *s;
 
   s = strrchr (name, '/');
   if (s && s[1])
     name = s + 1;
 
   n = npth_read (fd, &buf, sizeof buf);
   if (n < sizeof (struct inotify_event))
     return 0;
   if (buf.ev.len < strlen (name)+1)
     return 0;
   if (strcmp (buf.ev.name, name))
     return 0; /* Not the desired file.  */
 
   return 1; /* Found.  */
 }
 #endif /*HAVE_INOTIFY_INIT*/
 
 
 /* Main loop in daemon mode.  Note that LISTEN_FD will be owned by
  * this function. */
 static void
 handle_connections (assuan_fd_t listen_fd)
 {
   npth_attr_t tattr;
 #ifndef HAVE_W32_SYSTEM
   int signo;
 #endif
   struct sockaddr_un paddr;
   socklen_t plen = sizeof( paddr );
   int nfd, ret;
   fd_set fdset, read_fdset;
   struct timespec abstime;
   struct timespec curtime;
   struct timespec timeout;
   int saved_errno;
   int my_inotify_fd = -1;
 
   npth_attr_init (&tattr);
   npth_attr_setdetachstate (&tattr, NPTH_CREATE_DETACHED);
 
 #ifndef HAVE_W32_SYSTEM /* FIXME */
   npth_sigev_init ();
   npth_sigev_add (SIGHUP);
   npth_sigev_add (SIGUSR1);
   npth_sigev_add (SIGUSR2);
   npth_sigev_add (SIGINT);
   npth_sigev_add (SIGTERM);
   npth_sigev_fini ();
 #endif
 
 #ifdef HAVE_INOTIFY_INIT
   if (disable_check_own_socket)
     my_inotify_fd = -1;
   else if ((my_inotify_fd = inotify_init ()) == -1)
     log_info ("error enabling fast daemon termination: %s\n",
               strerror (errno));
   else
     {
       /* We need to watch the directory for the file because there
        * won't be an IN_DELETE_SELF for a socket file.  */
       char *slash = strrchr (socket_name, '/');
       log_assert (slash && slash[1]);
       *slash = 0;
       if (inotify_add_watch (my_inotify_fd, socket_name, IN_DELETE) == -1)
         {
           close (my_inotify_fd);
           my_inotify_fd = -1;
         }
       *slash = '/';
     }
 #endif /*HAVE_INOTIFY_INIT*/
 
 
   /* Setup the fdset.  It has only one member.  This is because we use
      pth_select instead of pth_accept to properly sync timeouts with
      to full second.  */
   FD_ZERO (&fdset);
   FD_SET (FD2INT (listen_fd), &fdset);
   nfd = FD2INT (listen_fd);
   if (my_inotify_fd != -1)
     {
       FD_SET (my_inotify_fd, &fdset);
       if (my_inotify_fd > nfd)
         nfd = my_inotify_fd;
     }
 
   npth_clock_gettime (&abstime);
   abstime.tv_sec += TIMERTICK_INTERVAL;
 
   /* Main loop.  */
   for (;;)
     {
       /* Shutdown test.  */
       if (shutdown_pending)
         {
           if (!active_connections)
             break; /* ready */
 
           /* Do not accept new connections but keep on running the
            * loop to cope with the timer events.
            *
            * Note that we do not close the listening socket because a
            * client trying to connect to that socket would instead
            * restart a new dirmngr instance - which is unlikely the
            * intention of a shutdown. */
           /* assuan_sock_close (listen_fd); */
           /* listen_fd = -1; */
           FD_ZERO (&fdset);
           nfd = -1;
           if (my_inotify_fd != -1)
             {
               FD_SET (my_inotify_fd, &fdset);
               nfd = my_inotify_fd;
             }
 	}
 
       /* Take a copy of the fdset.  */
       read_fdset = fdset;
 
       npth_clock_gettime (&curtime);
       if (!(npth_timercmp (&curtime, &abstime, <)))
 	{
 	  /* Timeout.  When a shutdown is pending we use a shorter
            * interval to handle the shutdown more quickly.  */
 	  handle_tick ();
 	  npth_clock_gettime (&abstime);
 	  abstime.tv_sec += (shutdown_pending
                              ? TIMERTICK_INTERVAL_SHUTDOWN
                              : TIMERTICK_INTERVAL);
 	}
       npth_timersub (&abstime, &curtime, &timeout);
 
 #ifndef HAVE_W32_SYSTEM
       ret = npth_pselect (nfd+1, &read_fdset, NULL, NULL, &timeout,
                           npth_sigev_sigmask());
       saved_errno = errno;
 
       while (npth_sigev_get_pending(&signo))
 	handle_signal (signo);
 #else
       ret = npth_eselect (nfd+1, &read_fdset, NULL, NULL, &timeout, NULL, NULL);
       saved_errno = errno;
 #endif
 
       if (ret == -1 && saved_errno != EINTR)
 	{
           log_error (_("npth_pselect failed: %s - waiting 1s\n"),
                      strerror (saved_errno));
           npth_sleep (1);
           continue;
 	}
 
       if (ret <= 0)
         {
           /* Interrupt or timeout.  Will be handled when calculating the
              next timeout.  */
           continue;
         }
 
       if (shutdown_pending)
         {
           /* Do not anymore accept connections.  */
           continue;
         }
 
 #ifdef HAVE_INOTIFY_INIT
       if (my_inotify_fd != -1 && FD_ISSET (my_inotify_fd, &read_fdset)
           && my_inotify_is_name (my_inotify_fd, socket_name))
         {
           shutdown_pending = 1;
           log_info ("socket file has been removed - shutting down\n");
         }
 #endif /*HAVE_INOTIFY_INIT*/
 
       if (FD_ISSET (FD2INT (listen_fd), &read_fdset))
 	{
           gnupg_fd_t fd;
 
           plen = sizeof paddr;
 	  fd = INT2FD (npth_accept (FD2INT(listen_fd),
 				    (struct sockaddr *)&paddr, &plen));
 	  if (fd == GNUPG_INVALID_FD)
 	    {
 	      log_error ("accept failed: %s\n", strerror (errno));
 	    }
           else
             {
               char threadname[50];
               union int_and_ptr_u argval;
 	      npth_t thread;
 
               memset (&argval, 0, sizeof argval);
               argval.afd = fd;
               snprintf (threadname, sizeof threadname,
                         "conn fd=%d", FD2INT(fd));
 
               ret = npth_create (&thread, &tattr,
                                  start_connection_thread, argval.aptr);
 	      if (ret)
                 {
                   log_error ("error spawning connection handler: %s\n",
                              strerror (ret) );
                   assuan_sock_close (fd);
                 }
 	      npth_setname_np (thread, threadname);
             }
 	}
     }
 
 #ifdef HAVE_INOTIFY_INIT
   if (my_inotify_fd != -1)
     close (my_inotify_fd);
 #endif /*HAVE_INOTIFY_INIT*/
   npth_attr_destroy (&tattr);
   if (listen_fd != GNUPG_INVALID_FD)
     assuan_sock_close (listen_fd);
   cleanup ();
   log_info ("%s %s stopped\n", strusage(11), strusage(13));
 }
 
 const char*
 dirmngr_get_current_socket_name (void)
 {
   if (socket_name)
     return socket_name;
   else
     return dirmngr_socket_name ();
 }
 
 
 
 /* Parse the revision part from the extended version blurb.  */
 static const char *
 get_revision_from_blurb (const char *blurb, int *r_len)
 {
   const char *s = blurb? blurb : "";
   int n;
 
   for (; *s; s++)
     if (*s == '\n' && s[1] == '(')
       break;
   if (*s)
     {
       s += 2;
       for (n=0; s[n] && s[n] != ' '; n++)
         ;
     }
   else
     {
       s = "?";
       n = 1;
     }
   *r_len = n;
   return s;
 }
 
 
 /* Print versions of dirmngr and used libraries.  This is used by
  * "gpgconf --show-versions" so that there is no need to link gpgconf
  * against all these libraries.  This is an internal API and should
  * not be relied upon.  */
 static void
 gpgconf_versions (void)
 {
   const char *s;
   int n;
 
   /* Unfortunately Npth has no way to get the version.  */
 
   s = get_revision_from_blurb (assuan_check_version ("\x01\x01"), &n);
   es_fprintf (es_stdout, "* Libassuan %s (%.*s)\n\n",
               assuan_check_version (NULL), n, s);
 
   s = get_revision_from_blurb (ksba_check_version ("\x01\x01"), &n);
   es_fprintf (es_stdout, "* KSBA %s (%.*s)\n\n",
               ksba_check_version (NULL), n, s);
 
 #ifdef HTTP_USE_NTBTLS
   s = get_revision_from_blurb (ntbtls_check_version ("\x01\x01"), &n);
   es_fprintf (es_stdout, "* NTBTLS %s (%.*s)\n\n",
               ntbtls_check_version (NULL), n, s);
 #elif HTTP_USE_GNUTLS
   es_fprintf (es_stdout, "* GNUTLS %s\n\n",
               gnutls_check_version (NULL));
 #endif
 
 }
diff --git a/dirmngr/dirmngr.h b/dirmngr/dirmngr.h
index fed459924..dd9f605da 100644
--- a/dirmngr/dirmngr.h
+++ b/dirmngr/dirmngr.h
@@ -1,288 +1,295 @@
 /* dirmngr.h - Common definitions for the dirmngr
  * Copyright (C) 2002 Klarälvdalens Datakonsult AB
  * Copyright (C) 2004, 2015 g10 Code GmbH
  * Copyright (C) 2014 Werner Koch
  *
  * 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/>.
  *
  * SPDX-License-Identifier: GPL-3.0+
  */
 
 #ifndef DIRMNGR_H
 #define DIRMNGR_H
 
 #include "./dirmngr-err.h"
 #define map_assuan_err(a) \
         map_assuan_err_with_source (GPG_ERR_SOURCE_DEFAULT, (a))
 #include <errno.h>
 #include <gcrypt.h>
 #include <ksba.h>
 
 #include "../common/util.h"
 #include "../common/membuf.h"
 #include "../common/sysutils.h" /* (gnupg_fd_t) */
 #include "../common/asshelp.h"  /* (assuan_context_t) */
 #include "../common/i18n.h"
 #include "dirmngr-status.h"
 #include "http.h"     /* (parsed_uri_t) */
 
 /* This objects keeps information about a particular LDAP server and
    is used as item of a single linked list of servers. */
 struct ldap_server_s
 {
   struct ldap_server_s* next;
 
   char *host;
   int   port;
   char *user;
   char *pass;
   char *base;
 
   unsigned int starttls:1;       /* Use STARTTLS.  */
   unsigned int ldap_over_tls:1;  /* Use LDAP over an TLS tunnel */
   unsigned int ntds:1;           /* Use Active Directory authentication.  */
   unsigned int areconly:1;       /* Set LDAP_OPT_AREC_EXCLUSIVE.  */
 };
 typedef struct ldap_server_s *ldap_server_t;
 
 
 /* This objects is used to build a list of URI consisting of the
    original and the parsed URI.  */
 struct uri_item_s
 {
   struct uri_item_s *next;
   parsed_uri_t parsed_uri;  /* The broken down URI.  */
   char uri[1];              /* The original URI.  */
 };
 typedef struct uri_item_s *uri_item_t;
 
 
 /* A list of fingerprints.  */
 struct fingerprint_list_s;
 typedef struct fingerprint_list_s *fingerprint_list_t;
 struct fingerprint_list_s
 {
   fingerprint_list_t next;
   char binlen;  /* If this is not 0 hexfpr actually carries a binary fpr.  */
   char hexfpr[20+20+1];
 };
 
 
 /* A large struct named "opt" to keep global flags.  */
 EXTERN_UNLESS_MAIN_MODULE
 struct
 {
   unsigned int debug; /* debug flags (DBG_foo_VALUE) */
   int verbose;        /* verbosity level */
   int quiet;          /* be as quiet as possible */
   int dry_run;        /* don't change any persistent data */
   int batch;          /* batch mode */
   const char *homedir_cache; /* Dir for cache files (/var/cache/dirmngr).  */
 
   char *config_filename;     /* Name of a config file, which will be
                                 reread on a HUP if it is not NULL. */
 
   char *ldap_wrapper_program; /* Override value for the LDAP wrapper
                                  program.  */
   char *http_wrapper_program; /* Override value for the HTTP wrapper
                                  program.  */
 
   int running_detached; /* We are running in detached mode.  */
   int allow_version_check; /* --allow-version-check is active.  */
 
   int force;          /* Force loading outdated CRLs. */
 
 
   unsigned int connect_timeout;       /* Timeout for connect.  */
   unsigned int connect_quick_timeout; /* Shorter timeout for connect.  */
 
   int disable_http;       /* Do not use HTTP at all.  */
   int disable_ldap;       /* Do not use LDAP at all.  */
   int disable_ipv4;       /* Do not use legacy IP addresses.  */
   int disable_ipv6;       /* Do not use standard IP addresses.  */
   int honor_http_proxy;   /* Honor the http_proxy env variable. */
   const char *http_proxy; /* The default HTTP proxy.  */
   const char *ldap_proxy; /* Use given LDAP proxy.  */
   int only_ldap_proxy;    /* Only use the LDAP proxy; no fallback.  */
   int ignore_http_dp;     /* Ignore HTTP CRL distribution points.  */
   int ignore_ldap_dp;     /* Ignore LDAP CRL distribution points.  */
   int ignore_ocsp_service_url; /* Ignore OCSP service URLs as given in
                                   the certificate.  */
 
   /* A list of fingerprints of certififcates we should completely
    * ignore.  These are all stored in binary format.  */
   fingerprint_list_t ignored_certs;
 
   /* A list of certificate extension OIDs which are ignored so that
      one can claim that a critical extension has been handled.  One
      OID per string.  */
   strlist_t ignored_cert_extensions;
 
   /* Allow expired certificates in the cache.  */
   int debug_cache_expired_certs;
 
   int allow_ocsp;     /* Allow using OCSP. */
 
   int max_replies;
   unsigned int ldaptimeout;
 
   ldap_server_t ldapservers;
   int add_new_ldapservers;
 
   const char *ocsp_responder;     /* Standard OCSP responder's URL. */
   fingerprint_list_t ocsp_signer; /* The list of fingerprints with allowed
                                      standard OCSP signer certificates.  */
 
   unsigned int ocsp_max_clock_skew; /* Allowed seconds of clocks skew. */
   unsigned int ocsp_max_period;     /* Seconds a response is at maximum
                                        considered valid after thisUpdate. */
   unsigned int ocsp_current_period; /* Seconds a response is considered
                                        current after nextUpdate. */
 
   strlist_t keyserver;              /* List of default keyservers.  */
+
+  /* Compatibility flags (COMPAT_FLAG_xxxx).  */
+  unsigned int compat_flags;
 } opt;
 
 
 #define DBG_X509_VALUE    1	/* debug x.509 parsing */
 #define DBG_CRYPTO_VALUE  4	/* debug low level crypto */
 #define DBG_DNS_VALUE     16    /* debug DNS calls.  */
 #define DBG_MEMORY_VALUE  32	/* debug memory allocation stuff */
 #define DBG_CACHE_VALUE   64	/* debug the caching */
 #define DBG_MEMSTAT_VALUE 128	/* show memory statistics */
 #define DBG_HASHING_VALUE 512	/* debug hashing operations */
 #define DBG_IPC_VALUE     1024  /* debug assuan communication */
 #define DBG_NETWORK_VALUE 2048  /* debug network I/O.  */
 #define DBG_LOOKUP_VALUE  8192  /* debug lookup details */
 #define DBG_EXTPROG_VALUE 16384 /* debug external program calls */
 
 #define DBG_X509    (opt.debug & DBG_X509_VALUE)
 #define DBG_CRYPTO  (opt.debug & DBG_CRYPTO_VALUE)
 #define DBG_DNS     (opt.debug & DBG_DNS_VALUE)
 #define DBG_MEMORY  (opt.debug & DBG_MEMORY_VALUE)
 #define DBG_CACHE   (opt.debug & DBG_CACHE_VALUE)
 #define DBG_HASHING (opt.debug & DBG_HASHING_VALUE)
 #define DBG_IPC     (opt.debug & DBG_IPC_VALUE)
 #define DBG_NETWORK (opt.debug & DBG_NETWORK_VALUE)
 #define DBG_LOOKUP  (opt.debug & DBG_LOOKUP_VALUE)
 #define DBG_EXTPROG (opt.debug & DBG_EXTPROG_VALUE)
 
+/* Compatibility flags */
+/* None so far.  */
+
+
 /* A simple list of certificate references.  FIXME: Better use
    certlist_t also for references (Store NULL at .cert) */
 struct cert_ref_s
 {
   struct cert_ref_s *next;
   unsigned char fpr[20];
 };
 typedef struct cert_ref_s *cert_ref_t;
 
 /* Forward reference; access only via ks-engine-ldap.c.  */
 struct ks_engine_ldap_local_s;
 
 /* Forward reference; access only through server.c.  */
 struct server_local_s;
 
 #if SIZEOF_UNSIGNED_LONG == 8
 # define SERVER_CONTROL_MAGIC 0x6469726d6e677220
 #else
 # define SERVER_CONTROL_MAGIC 0x6469726d
 #endif
 
 /* Connection control structure.  */
 struct server_control_s
 {
   unsigned long magic;/* Always has SERVER_CONTROL_MAGIC.  */
   int refcount;       /* Count additional references to this object.  */
   int no_server;      /* We are not running under server control. */
   int status_fd;      /* Only for non-server mode. */
   struct server_local_s *server_local;
   struct ks_engine_ldap_local_s *ks_get_state;
   int force_crl_refresh; /* Always load a fresh CRL. */
 
   int check_revocations_nest_level; /* Internal to check_revovations.  */
   cert_ref_t ocsp_certs; /* Certificates from the current OCSP
                             response. */
 
   int audit_events;  /* Send audit events to client.  */
   char *http_proxy;  /* The used http_proxy or NULL.  */
 
   unsigned int timeout; /* Timeout for connect calls in ms.  */
 
   unsigned int http_no_crl:1;  /* Do not check CRLs for https.  */
 };
 
 
 /*-- dirmngr.c --*/
 void dirmngr_exit( int );  /* Wrapper for exit() */
 void dirmngr_init_default_ctrl (ctrl_t ctrl);
 void dirmngr_deinit_default_ctrl (ctrl_t ctrl);
 void dirmngr_sighup_action (void);
 const char* dirmngr_get_current_socket_name (void);
 int dirmngr_use_tor (void);
 int dirmngr_never_use_tor_p (void);
 
 /*-- Various housekeeping functions.  --*/
 void ks_hkp_housekeeping (time_t curtime);
 void ks_hkp_reload (void);
 
 
 /*-- server.c --*/
 ldap_server_t get_ldapservers_from_ctrl (ctrl_t ctrl);
 ksba_cert_t get_cert_local (ctrl_t ctrl, const char *issuer);
 ksba_cert_t get_issuing_cert_local (ctrl_t ctrl, const char *issuer);
 ksba_cert_t get_cert_local_ski (ctrl_t ctrl,
                                 const char *name, ksba_sexp_t keyid);
 gpg_error_t get_istrusted_from_client (ctrl_t ctrl, const char *hexfpr);
 int dirmngr_assuan_log_monitor (assuan_context_t ctx, unsigned int cat,
                                 const char *msg);
 void start_command_handler (gnupg_fd_t fd, unsigned int session_id);
 gpg_error_t dirmngr_tick (ctrl_t ctrl);
 
 /* (See also dirmngr-status.h)  */
 
 /*-- http-ntbtls.c --*/
 /* Note that we don't use a callback for gnutls.  */
 
 gpg_error_t gnupg_http_tls_verify_cb (void *opaque,
                                       http_t http,
                                       http_session_t session,
                                       unsigned int flags,
                                       void *tls_context);
 
 
 /*-- loadswdb.c --*/
 gpg_error_t dirmngr_load_swdb (ctrl_t ctrl, int force);
 
 
 /*-- domaininfo.c --*/
 void domaininfo_print_stats (void);
 int  domaininfo_is_wkd_not_supported (const char *domain);
 void domaininfo_set_no_name (const char *domain);
 void domaininfo_set_wkd_supported (const char *domain);
 void domaininfo_set_wkd_not_supported (const char *domain);
 void domaininfo_set_wkd_not_found (const char *domain);
 
 /*-- workqueue.c --*/
 typedef const char *(*wqtask_t)(ctrl_t ctrl, const char *args);
 
 void workqueue_dump_queue (ctrl_t ctrl);
 gpg_error_t workqueue_add_task (wqtask_t func, const char *args,
                                 unsigned int session_id, int need_network);
 void workqueue_run_global_tasks (ctrl_t ctrl, int with_network);
 void workqueue_run_post_session_tasks (unsigned int session_id);
 
 
 
 #endif /*DIRMNGR_H*/
diff --git a/doc/dirmngr.texi b/doc/dirmngr.texi
index 7b539ca4e..f9da5f090 100644
--- a/doc/dirmngr.texi
+++ b/doc/dirmngr.texi
@@ -1,1273 +1,1281 @@
 @c Copyright (C) 2002 Klar"alvdalens Datakonsult AB
 @c Copyright (C) 2004, 2005, 2006, 2007 g10 Code GmbH
 @c This is part of the GnuPG manual.
 @c For copying conditions, see the file gnupg.texi.
 
 @include defs.inc
 
 @node Invoking DIRMNGR
 @chapter Invoking DIRMNGR
 @cindex DIRMNGR command options
 @cindex command options
 @cindex options, DIRMNGR command
 
 @manpage dirmngr.8
 @ifset manverb
 .B dirmngr
 \- GnuPG's network access daemon
 @end ifset
 
 @mansect synopsis
 @ifset manverb
 .B  dirmngr
 .RI [ options ]
 .I command
 .RI [ args ]
 @end ifset
 
 @mansect description
 Since version 2.1 of GnuPG, @command{dirmngr} takes care of accessing
 the OpenPGP keyservers.  As with previous versions it is also used as
 a server for managing and downloading certificate revocation lists
 (CRLs) for X.509 certificates, downloading X.509 certificates, and
 providing access to OCSP providers.  Dirmngr is invoked internally by
 @command{gpg}, @command{gpgsm}, or via the @command{gpg-connect-agent}
 tool.
 
 @manpause
 @noindent
 @xref{Option Index},for an index to @command{DIRMNGR}'s commands and
 options.
 @mancont
 
 @menu
 * Dirmngr Commands::      List of all commands.
 * Dirmngr Options::       List of all options.
 * Dirmngr Configuration:: Configuration files.
 * Dirmngr Signals::       Use of signals.
 * Dirmngr Examples::      Some usage examples.
 * Dirmngr Protocol::      The protocol dirmngr uses.
 @end menu
 
 
 @node Dirmngr Commands
 @section Commands
 @mansect commands
 
 Commands are not distinguished from options except for the fact that
 only one command is allowed.
 
 @table @gnupgtabopt
 @item --version
 @opindex version
 Print the program version and licensing information.  Note that you cannot
 abbreviate this command.
 
 @item --help, -h
 @opindex help
 Print a usage message summarizing the most useful command-line options.
 Note that you cannot abbreviate this command.
 
 @item --dump-options
 @opindex dump-options
 Print a list of all available options and commands.  Note that you cannot
 abbreviate this command.
 
 @item --server
 @opindex server
 Run in server mode and wait for commands on the @code{stdin}.  The
 default mode is to create a socket and listen for commands there.
 This is only used for testing.
 
 @item --daemon
 @opindex daemon
 Run in background daemon mode and listen for commands on a socket.
 This is the way @command{dirmngr} is started on demand by the other
 GnuPG components.  To force starting @command{dirmngr} it is in
 general best to use @code{gpgconf --launch dirmngr}.
 
 @item --supervised
 @opindex supervised
 Run in the foreground, sending logs to stderr, and listening on file
 descriptor 3, which must already be bound to a listening socket.  This
 is useful when running under systemd or other similar process
 supervision schemes.  This option is not supported on Windows.
 
 @item --list-crls
 @opindex list-crls
 List the contents of the CRL cache on @code{stdout}. This is probably
 only useful for debugging purposes.
 
 @item --load-crl @var{file}
 @opindex load-crl
 This command requires a filename as additional argument, and it will
 make Dirmngr try to import the CRL in @var{file} into it's cache.
 Note, that this is only possible if Dirmngr is able to retrieve the
 CA's certificate directly by its own means.  In general it is better
 to use @code{gpgsm}'s @code{--call-dirmngr loadcrl filename} command
 so that @code{gpgsm} can help dirmngr.
 
 @item --fetch-crl @var{url}
 @opindex fetch-crl
 This command requires an URL as additional argument, and it will make
 dirmngr try to retrieve and import the CRL from that @var{url} into
 it's cache.  This is mainly useful for debugging purposes.  The
 @command{dirmngr-client} provides the same feature for a running dirmngr.
 
 @item --shutdown
 @opindex shutdown
 This commands shuts down an running instance of Dirmngr.  This command
 has currently no effect.
 
 @item --flush
 @opindex flush
 This command removes all CRLs from Dirmngr's cache.  Client requests
 will thus trigger reading of fresh CRLs.
 
 @end table
 
 
 @mansect options
 @node Dirmngr Options
 @section Option Summary
 
 Note that all long options with the exception of @option{--options}
 and @option{--homedir} may also be given in the configuration file
 after stripping off the two leading dashes.
 
 @table @gnupgtabopt
 
 @item --options @var{file}
 @opindex options
 Reads configuration from @var{file} instead of from the default
 per-user configuration file.  The default configuration file is named
 @file{dirmngr.conf} and expected in the home directory.
 
 @item --homedir @var{dir}
 @opindex options
 Set the name of the home directory to @var{dir}.  This option is only
 effective when used on the command line.  The default is
 the directory named @file{.gnupg} directly below the home directory
 of the user unless the environment variable @code{GNUPGHOME} has been set
 in which case its value will be used.  Many kinds of data are stored within
 this directory.
 
 
 @item -v
 @item --verbose
 @opindex v
 @opindex verbose
 Outputs additional information while running.
 You can increase the verbosity by giving several
 verbose commands to @sc{dirmngr}, such as @option{-vv}.
 
 
 @item --log-file @var{file}
 @opindex log-file
 Append all logging output to @var{file}.  This is very helpful in
 seeing what the agent actually does.  Use @file{socket://} to log to
 socket.
 
+@item --compatibility-flags @var{flags}
+@opindex compatibility-flags
+Set compatibility flags to work around certain problems or to emulate
+bugs.  The @var{flags} are given as a comma separated list of flag
+names and are OR-ed together.  The special flag "none" clears the list
+and allows to start over with an empty list.  To get a list of
+available flags the sole word "help" can be used.
+
 @item --debug-level @var{level}
 @opindex debug-level
 Select the debug level for investigating problems.  @var{level} may be a
 numeric value or by a keyword:
 
 @table @code
 @item none
 No debugging at all.  A value of less than 1 may be used instead of
 the keyword.
 @item basic
 Some basic debug messages.  A value between 1 and 2 may be used
 instead of the keyword.
 @item advanced
 More verbose debug messages.  A value between 3 and 5 may be used
 instead of the keyword.
 @item expert
 Even more detailed messages.  A value between 6 and 8 may be used
 instead of the keyword.
 @item guru
 All of the debug messages you can get. A value greater than 8 may be
 used instead of the keyword.  The creation of hash tracing files is
 only enabled if the keyword is used.
 @end table
 
 How these messages are mapped to the actual debugging flags is not
 specified and may change with newer releases of this program. They are
 however carefully selected to best aid in debugging.
 
 @item --debug @var{flags}
 @opindex debug
 Set debugging flags.  This option is only useful for debugging and its
 behavior may change with a new release.  All flags are or-ed and may
 be given in C syntax (e.g. 0x0042) or as a comma separated list of
 flag names.  To get a list of all supported flags the single word
 "help" can be used.
 
 @item --debug-all
 @opindex debug-all
 Same as @code{--debug=0xffffffff}
 
 @item --tls-debug @var{level}
 @opindex tls-debug
 Enable debugging of the TLS layer at @var{level}.  The details of the
 debug level depend on the used TLS library and are not set in stone.
 
 @item --debug-wait @var{n}
 @opindex debug-wait
 When running in server mode, wait @var{n} seconds before entering the
 actual processing loop and print the pid.  This gives time to attach a
 debugger.
 
 @item --disable-check-own-socket
 @opindex disable-check-own-socket
 On some platforms @command{dirmngr} is able to detect the removal of
 its socket file and shutdown itself.  This option disable this
 self-test for debugging purposes.
 
 @item -s
 @itemx --sh
 @itemx -c
 @itemx --csh
 @opindex s
 @opindex sh
 @opindex c
 @opindex csh
 Format the info output in daemon mode for use with the standard Bourne
 shell respective the C-shell. The default is to guess it based on the
 environment variable @code{SHELL} which is in almost all cases
 sufficient.
 
 @item --force
 @opindex force
 Enabling this option forces loading of expired CRLs; this is only
 useful for debugging.
 
 @item --use-tor
 @itemx --no-use-tor
 @opindex use-tor
 @opindex no-use-tor
 The option @option{--use-tor} switches Dirmngr and thus GnuPG into
 ``Tor mode'' to route all network access via Tor (an anonymity
 network).  Certain other features are disabled in this mode.  The
 effect of @option{--use-tor} cannot be overridden by any other command
 or even by reloading dirmngr.  The use of @option{--no-use-tor}
 disables the use of Tor.  The default is to use Tor if it is available
 on startup or after reloading dirmngr.  The test on the available of
 Tor is done by trying to connects to a SOCKS proxy at either port 9050
 or 9150); if another type of proxy is listening on one of these ports,
 you should use @option{--no-use-tor}.
 
 @item --standard-resolver
 @opindex standard-resolver
 This option forces the use of the system's standard DNS resolver code.
 This is mainly used for debugging.  Note that on Windows a standard
 resolver is not used and all DNS access will return the error ``Not
 Implemented'' if this option is used.  Using this together with enabled
 Tor mode returns the error ``Not Enabled''.
 
 @item --recursive-resolver
 @opindex recursive-resolver
 When possible use a recursive resolver instead of a stub resolver.
 
 @item --resolver-timeout @var{n}
 @opindex resolver-timeout
 Set the timeout for the DNS resolver to N seconds.  The default are 30
 seconds.
 
 @item --connect-timeout @var{n}
 @item --connect-quick-timeout @var{n}
 @opindex connect-timeout
 @opindex connect-quick-timeout
 Set the timeout for HTTP and generic TCP connection attempts to N
 seconds.  The value set with the quick variant is used when the
 --quick option has been given to certain Assuan commands.  The quick
 value is capped at the value of the regular connect timeout.  The
 default values are 15 and 2 seconds.  Note that the timeout values are
 for each connection attempt; the connection code will attempt to
 connect all addresses listed for a server.
 
 @item --listen-backlog @var{n}
 @opindex listen-backlog
 Set the size of the queue for pending connections.  The default is 64.
 
 @item --allow-version-check
 @opindex allow-version-check
 Allow Dirmngr to connect to @code{https://versions.gnupg.org} to get
 the list of current software versions.  If this option is enabled
 the list is retrieved in case the local
 copy does not exist or is older than 5 to 7 days.  See the option
 @option{--query-swdb} of the command @command{gpgconf} for more
 details.  Note, that regardless of this option a version check can
 always be triggered using this command:
 
 @example
        gpg-connect-agent --dirmngr 'loadswdb --force' /bye
 @end example
 
 
 @item --keyserver @var{name}
 @opindex keyserver
 Use @var{name} as your keyserver.  This is the server that @command{gpg}
 communicates with to receive keys, send keys, and search for
 keys.  The format of the @var{name} is a URI:
 `scheme:[//]keyservername[:port]' The scheme is the type of keyserver:
 "hkp" for the HTTP (or compatible) keyservers, "ldap" for the LDAP
 keyservers, or "mailto" for the Graff email keyserver. Note that your
 particular installation of GnuPG may have other keyserver types
 available as well. Keyserver schemes are case-insensitive. After the
 keyserver name, optional keyserver configuration options may be
 provided.  These are the same as the @option{--keyserver-options} of
 @command{gpg}, but apply only to this particular keyserver.
 
 Some keyservers synchronize with each other, so there is not always a
 need to send keys to more than one server. Some keyservers use round
 robin DNS to give a different keyserver each time you use it.
 
 If exactly two keyservers are configured and only one is a Tor hidden
 service (.onion), Dirmngr selects the keyserver to use depending on
 whether Tor is locally running or not.  The check for a running Tor is
 done for each new connection.
 
 If no keyserver is explicitly configured, dirmngr will use the
 built-in default of @code{https://keyserver.ubuntu.com}.
 
 Windows users with a keyserver running on their Active Directory
 may use the short form @code{ldap:///} for @var{name} to access this directory.
 
 For accessing anonymous LDAP keyservers @var{name} is in general just
 a @code{ldaps://ldap.example.com}.  A BaseDN parameter should never be
 specified.  If authentication is required things are more complicated
 and two methods are available:
 
 The modern method (since version 2.2.28) is to use the very same syntax
 as used with the option @option{--ldapserver}.  Please see over
 there for details; here is an example:
 
 @example
        keyserver ldap:ldap.example.com::uid=USERNAME,ou=GnuPG Users,
        dc=example,dc=com:PASSWORD::starttls
 @end example
 
        The other method is to use a full URL for @var{name}; for example:
 
 @example
        keyserver ldaps://ldap.example.com/????bindname=uid=USERNAME
        %2Cou=GnuPG%20Users%2Cdc=example%2Cdc=com,password=PASSWORD
 @end example
 
        Put this all on one line without any spaces and keep the '%2C'
        as given.  Replace USERNAME, PASSWORD, and the 'dc' parts
        according to the instructions received from your LDAP
        administrator.  Note that only simple authentication
        (i.e. cleartext passwords) is supported and thus using ldaps is
        strongly suggested (since 2.2.28 "ldaps" defaults to port 389
        and uses STARTTLS).  On Windows authentication via AD can be
        requested by adding @code{gpgNtds=1} after the fourth question
        mark instead of the bindname and password parameter.
 
 
 
 @item --nameserver @var{ipaddr}
 @opindex nameserver
 In ``Tor mode'' Dirmngr uses a public resolver via Tor to resolve DNS
 names.  If the default public resolver, which is @code{8.8.8.8}, shall
 not be used a different one can be given using this option.  Note that
 a numerical IP address must be given (IPv6 or IPv4) and that no error
 checking is done for @var{ipaddr}.
 
 @item --disable-ipv4
 @item --disable-ipv6
 @opindex disable-ipv4
 @opindex disable-ipv6
 Disable the use of all IPv4 or IPv6 addresses.
 
 @item --disable-ldap
 @opindex disable-ldap
 Entirely disables the use of LDAP.
 
 @item --disable-http
 @opindex disable-http
 Entirely disables the use of HTTP.
 
 @item --ignore-http-dp
 @opindex ignore-http-dp
 When looking for the location of a CRL, the to be tested certificate
 usually contains so called @dfn{CRL Distribution Point} (DP) entries
 which are URLs describing the way to access the CRL.  The first found DP
 entry is used.  With this option all entries using the @acronym{HTTP}
 scheme are ignored when looking for a suitable DP.
 
 @item --ignore-ldap-dp
 @opindex ignore-ldap-dp
 This is similar to @option{--ignore-http-dp} but ignores entries using
 the @acronym{LDAP} scheme.  Both options may be combined resulting in
 ignoring DPs entirely.
 
 @item --ignore-ocsp-service-url
 @opindex ignore-ocsp-service-url
 Ignore all OCSP URLs contained in the certificate.  The effect is to
 force the use of the default responder.
 
 @item --honor-http-proxy
 @opindex honor-http-proxy
 If the environment variable @env{http_proxy} has been set, use its
 value to access HTTP servers.
 
 @item --http-proxy [http://]@var{host}[:@var{port}]
 @opindex http-proxy
 @efindex http_proxy
 Use @var{host} and @var{port} to access HTTP servers.  The use of this
 option overrides the environment variable @env{http_proxy} regardless
 whether @option{--honor-http-proxy} has been set.
 
 
 @item --ldap-proxy @var{host}[:@var{port}]
 @opindex ldap-proxy
 Use @var{host} and @var{port} to connect to LDAP servers.  If @var{port}
 is omitted, port 389 (standard LDAP port) is used.  This overrides any
 specified host and port part in a LDAP URL and will also be used if host
 and port have been omitted from the URL.
 
 @item --only-ldap-proxy
 @opindex only-ldap-proxy
 Never use anything else but the LDAP "proxy" as configured with
 @option{--ldap-proxy}.  Usually @command{dirmngr} tries to use other
 configured LDAP server if the connection using the "proxy" failed.
 
 
 @item --ldapserverlist-file @var{file}
 @opindex ldapserverlist-file
 Read the list of LDAP servers to consult for CRLs and X.509 certificates from
 file instead of the default per-user ldap server list file. The default
 value for @var{file} is @file{dirmngr_ldapservers.conf}.
 
 This server list file contains one LDAP server per line in the format
 
 @sc{hostname:port:username:password:base_dn:flags}
 
 Lines starting with a  @samp{#} are comments.
 
 Note that as usual all strings entered are expected to be UTF-8 encoded.
 Obviously this will lead to problems if the password has originally been
 encoded as Latin-1.  There is no other solution here than to put such a
 password in the binary encoding into the file (i.e. non-ascii characters
 won't show up readable).@footnote{The @command{gpgconf} tool might be
 helpful for frontends as it enables editing this configuration file using
 percent-escaped strings.}
 
 
 @item --ldapserver @var{spec}
 @opindex ldapserver
 This is an alternative way to specify LDAP servers for CRL and X.509
 certificate retrieval.  If this option is used the servers configured
 in @file{dirmngr_ldapservers.conf} (or the file given by
 @option{--ldapserverlist-file}) are cleared.  Note that
 @file{dirmngr_ldapservers.conf} is not read again by a reload
 signal. However, @option{--ldapserver} options are read again.
 
 @var{spec} is either a proper LDAP URL or a colon delimited list of
 the form
 
 @sc{hostname:port:username:password:base_dn:flags:}
 
 with an optional prefix of @code{ldap:} (but without the two slashes
 which would turn this into a proper LDAP URL).  @sc{flags} is a list
 of one or more comma delimited keywords:
 @table @code
 @item plain
 The default: Do not use a TLS secured connection at all; the default
 port is 389.
 @item starttls
 Use STARTTLS to secure the connection; the default port is 389.
 @item ldaptls
 Tunnel LDAP through a TLS connection; the default port is 636.
 @item ntds
 On Windows authenticate the LDAP connection using the Active Directory
 with the current user.
 @item areconly
 On Windows use only the A or AAAA record when resolving the LDAP
 server name.
 @end table
 
 Note that in an URL style specification the scheme @code{ldaps://}
 refers to STARTTLS and _not_ to LDAP-over-TLS.
 
 
 @item --ldaptimeout @var{secs}
 @opindex ldaptimeout
 Specify the number of seconds to wait for an LDAP query before timing
 out.  The default are 15 seconds.  0 will never timeout.
 
 
 @item --add-servers
 @opindex add-servers
 This option makes dirmngr add any servers it discovers when validating
 certificates against CRLs to the internal list of servers to consult for
 certificates and CRLs.
 
 This option is useful when trying to validate a certificate that has
 a CRL distribution point that points to a server that is not already
 listed in the ldapserverlist. Dirmngr will always go to this server and
 try to download the CRL, but chances are high that the certificate used
 to sign the CRL is located on the same server. So if dirmngr doesn't add
 that new server to list, it will often not be able to verify the
 signature of the CRL unless the @code{--add-servers} option is used.
 
 Note: The current version of dirmngr has this option disabled by default.
 
 
 @item --allow-ocsp
 @opindex allow-ocsp
 This option enables OCSP support if requested by the client.
 
 OCSP requests are rejected by default because they may violate the
 privacy of the user; for example it is possible to track the time when
 a user is reading a mail.
 
 
 @item --ocsp-responder @var{url}
 @opindex ocsp-responder
 Use @var{url} as the default OCSP Responder if the certificate does
 not contain information about an assigned responder.  Note, that
 @code{--ocsp-signer} must also be set to a valid certificate.
 
 @item --ocsp-signer @var{fpr}|@var{file}
 @opindex ocsp-signer
 Use the certificate with the fingerprint @var{fpr} to check the
 responses of the default OCSP Responder.  Alternatively a filename can be
 given in which case the response is expected to be signed by one of the
 certificates described in that file.  Any argument which contains a
 slash, dot or tilde is considered a filename.  Usual filename expansion
 takes place: A tilde at the start followed by a slash is replaced by the
 content of @env{HOME}, no slash at start describes a relative filename
 which will be searched at the home directory.  To make sure that the
 @var{file} is searched in the home directory, either prepend the name
 with "./" or use a name which contains a dot.
 
 If a response has been signed by a certificate described by these
 fingerprints no further check upon the validity of this certificate is
 done.
 
 The format of the @var{FILE} is a list of SHA-1 fingerprint, one per
 line with optional colons between the bytes.  Empty lines and lines
 prefix with a hash mark are ignored.
 
 
 @item --ocsp-max-clock-skew @var{n}
 @opindex ocsp-max-clock-skew
 The number of seconds a skew between the OCSP responder and them local
 clock is accepted.  Default is 600 (10 minutes).
 
 @item --ocsp-max-period @var{n}
 @opindex ocsp-max-period
 Seconds a response is at maximum considered valid after the time given
 in the thisUpdate field.  Default is 7776000 (90 days).
 
 @item --ocsp-current-period @var{n}
 @opindex ocsp-current-period
 The number of seconds an OCSP response is considered valid after the
 time given in the NEXT_UPDATE datum.  Default is 10800 (3 hours).
 
 
 @item --max-replies @var{n}
 @opindex max-replies
 Do not return more that @var{n} items in one query.  The default is
 10.
 
 @item --ignore-cert-extension @var{oid}
 @opindex ignore-cert-extension
 Add @var{oid} to the list of ignored certificate extensions.  The
 @var{oid} is expected to be in dotted decimal form, like
 @code{2.5.29.3}.  This option may be used more than once.  Critical
 flagged certificate extensions matching one of the OIDs in the list
 are treated as if they are actually handled and thus the certificate
 won't be rejected due to an unknown critical extension.  Use this
 option with care because extensions are usually flagged as critical
 for a reason.
 
 @item --ignore-cert @var{fpr}|@var{file}
 @opindex ignore-cert
 Entirely ignore certificates with the fingerprint @var{fpr}.  As an
 alternative to the fingerprint a filename can be given in which case
 all certificates described in that file are ignored.  Any argument
 which contains a slash, dot or tilde is considered a filename.  Usual
 filename expansion takes place: A tilde at the start followed by a
 slash is replaced by the content of @env{HOME}, no slash at start
 describes a relative filename which will be searched at the home
 directory.  To make sure that the @var{file} is searched in the home
 directory, either prepend the name with "./" or use a name which
 contains a dot.  The format of such a file is a list of SHA-1
 fingerprint, one per line with optional colons between the bytes.
 Empty lines and lines prefixed with a hash mark are ignored.
 
 This option is useful as a quick workaround to exclude certain
 certificates from the system store.
 
 
 @item --hkp-cacert @var{file}
 Use the root certificates in @var{file} for verification of the TLS
 certificates used with @code{hkps} (keyserver access over TLS).  If
 the file is in PEM format a suffix of @code{.pem} is expected for
 @var{file}.  This option may be given multiple times to add more
 root certificates.  Tilde expansion is supported.
 
 If no @code{hkp-cacert} directive is present, dirmngr will use the
 system CAs.
 
 @end table
 
 
 @c
 @c Dirmngr Configuration
 @c
 @mansect files
 @node Dirmngr Configuration
 @section Configuration
 
 Dirmngr makes use of several directories when running in daemon mode:
 There are a few configuration files whih control the operation of
 dirmngr.  By default they may all be found in the current home
 directory (@pxref{option --homedir}).
 
 @table @file
 
 @item dirmngr.conf
 @efindex dirmngr.conf
 This is the standard configuration file read by @command{dirmngr} on
 startup.  It may contain any valid long option; the leading two dashes
 may not be entered and the option may not be abbreviated.  This file
 is also read after a @code{SIGHUP} however not all options will
 actually have an effect.  This default name may be changed on the
 command line (@pxref{option --options}).  You should backup this file.
 
 @item /etc/gnupg/trusted-certs
 This directory should be filled with certificates of Root CAs you
 are trusting in checking the CRLs and signing OCSP Responses.
 
 Usually these are the same certificates you use with the applications
 making use of dirmngr.  It is expected that each of these certificate
 files contain exactly one @acronym{DER} encoded certificate in a file
 with the suffix @file{.crt} or @file{.der}.  @command{dirmngr} reads
 those certificates on startup and when given a SIGHUP.  Certificates
 which are not readable or do not make up a proper X.509 certificate
 are ignored; see the log file for details.
 
 Applications using dirmngr (e.g. gpgsm) can request these
 certificates to complete a trust chain in the same way as with the
 extra-certs directory (see below).
 
 Note that for OCSP responses the certificate specified using the option
 @option{--ocsp-signer} is always considered valid to sign OCSP requests.
 
 @item /etc/gnupg/extra-certs
 This directory may contain extra certificates which are preloaded
 into the internal cache on startup. Applications using dirmngr (e.g. gpgsm)
 can request cached certificates to complete a trust chain.
 This is convenient in cases you have a couple intermediate CA certificates
 or certificates usually used to sign OCSP responses.
 These certificates are first tried before going
 out to the net to look for them.  These certificates must also be
 @acronym{DER} encoded and suffixed with @file{.crt} or @file{.der}.
 
 @item ~/.gnupg/crls.d
 This directory is used to store cached CRLs.  The @file{crls.d}
 part will be created by dirmngr if it does not exists but you need to
 make sure that the upper directory exists.
 
 @end table
 @manpause
 
 To be able to see what's going on you should create the configure file
 @file{~/gnupg/dirmngr.conf} with at least one line:
 
 @example
 log-file ~/dirmngr.log
 @end example
 
 To be able to perform OCSP requests you probably want to add the line:
 
 @example
 allow-ocsp
 @end example
 
 To make sure that new options are read and that after the installation
 of a new GnuPG versions the installed dirmngr is running, you may want
 to kill an existing dirmngr first:
 
 @example
 gpgconf --kill dirmngr
 @end example
 
 You may check the log file to see whether all desired root
 certificates have been loaded correctly.
 
 
 @c
 @c Dirmngr Signals
 @c
 @mansect signals
 @node Dirmngr Signals
 @section Use of signals
 
 A running @command{dirmngr} may be controlled by signals, i.e. using
 the @command{kill} command to send a signal to the process.
 
 Here is a list of supported signals:
 
 @table @gnupgtabopt
 
 @item SIGHUP
 @cpindex SIGHUP
 This signal flushes all internally cached CRLs as well as any cached
 certificates.  Then the certificate cache is reinitialized as on
 startup.  Options are re-read from the configuration file.  Instead of
 sending this signal it is better to use
 @example
 gpgconf --reload dirmngr
 @end example
 
 @item SIGTERM
 @cpindex SIGTERM
 Shuts down the process but waits until all current requests are
 fulfilled.  If the process has received 3 of these signals and requests
 are still pending, a shutdown is forced.  You may also use
 @example
 gpgconf --kill dirmngr
 @end example
 instead of this signal
 
 @item SIGINT
 @cpindex SIGINT
 Shuts down the process immediately.
 
 
 @item SIGUSR1
 @cpindex SIGUSR1
 This prints some caching statistics to the log file.
 
 @end table
 
 
 
 @c
 @c  Examples
 @c
 @mansect examples
 @node Dirmngr Examples
 @section Examples
 
 Here is an example on how to show dirmngr's internal table of OpenPGP
 keyserver addresses.  The output is intended for debugging purposes
 and not part of a defined API.
 
 @example
   gpg-connect-agent --dirmngr 'keyserver --hosttable' /bye
 @end example
 
 To inhibit the use of a particular host you have noticed in one of the
 keyserver pools, you may use
 
 @example
  gpg-connect-agent --dirmngr 'keyserver --dead pgpkeys.bnd.de' /bye
 @end example
 
 The description of the @code{keyserver} command can be printed using
 
 @example
  gpg-connect-agent --dirmngr 'help keyserver' /bye
 @end example
 
 
 
 @c
 @c  Assuan Protocol
 @c
 @manpause
 @node Dirmngr Protocol
 @section Dirmngr's Assuan Protocol
 
 Assuan is the IPC protocol used to access dirmngr.  This is a
 description of the commands implemented by dirmngr.
 
 @menu
 * Dirmngr LOOKUP::      Look up a certificate via LDAP
 * Dirmngr ISVALID::     Validate a certificate using a CRL or OCSP.
 * Dirmngr CHECKCRL::    Validate a certificate using a CRL.
 * Dirmngr CHECKOCSP::   Validate a certificate using OCSP.
 * Dirmngr CACHECERT::   Put a certificate into the internal cache.
 * Dirmngr VALIDATE::    Validate a certificate for debugging.
 @end menu
 
 @node Dirmngr LOOKUP
 @subsection Return the certificate(s) found
 
 Lookup certificate.  To allow multiple patterns (which are ORed)
 quoting is required: Spaces are to be translated into "+" or into
 "%20"; obviously this requires that the usual escape quoting rules
 are applied.  The server responds with:
 
 @example
   S: D <DER encoded certificate>
   S: END
   S: D <second DER encoded certificate>
   S: END
   S: OK
 @end example
 
 In this example 2 certificates are returned.  The server may return
 any number of certificates; OK will also be returned when no
 certificates were found.  The dirmngr might return a status line
 
 @example
   S: S TRUNCATED <n>
 @end example
 
 
 To indicate that the output was truncated to N items due to a
 limitation of the server or by an arbitrary set limit.
 
 The option @option{--url} may be used if instead of a search pattern a
 complete URL to the certificate is known:
 
 @example
   C: LOOKUP --url CN%3DWerner%20Koch,o%3DIntevation%20GmbH,c%3DDE?userCertificate
 @end example
 
 If the option @option{--cache-only} is given, no external lookup is done
 so that only certificates from the cache are returned.
 
 With the option @option{--single}, the first and only the first match
 will be returned.  Unless option @option{--cache-only} is also used, no
 local lookup will be done in this case.
 
 
 
 @node Dirmngr ISVALID
 @subsection Validate a certificate using a CRL or OCSP
 
 @example
   ISVALID [--only-ocsp] [--force-default-responder] @var{certid}|@var{certfpr}
 @end example
 
 Check whether the certificate described by the @var{certid} has been
 revoked.  Due to caching, the Dirmngr is able to answer immediately in
 most cases.
 
 The @var{certid} is a hex encoded string consisting of two parts,
 delimited by a single dot.  The first part is the SHA-1 hash of the
 issuer name and the second part the serial number.
 
 Alternatively the certificate's SHA-1 fingerprint @var{certfpr} may be
 given in which case an OCSP request is done before consulting the CRL.
 If the option @option{--only-ocsp} is given, no fallback to a CRL check
 will be used.  If the option @option{--force-default-responder} is
 given, only the default OCSP responder will be used and any other
 methods of obtaining an OCSP responder URL won't be used.
 
 @noindent
 Common return values are:
 
 @table @code
 @item GPG_ERR_NO_ERROR (0)
 This is the positive answer: The certificate is not revoked and we have
 an up-to-date revocation list for that certificate.  If OCSP was used
 the responder confirmed that the certificate has not been revoked.
 
 @item GPG_ERR_CERT_REVOKED
 This is the negative answer: The certificate has been revoked.  Either
 it is in a CRL and that list is up to date or an OCSP responder informed
 us that it has been revoked.
 
 @item GPG_ERR_NO_CRL_KNOWN
 No CRL is known for this certificate or the CRL is not valid or out of
 date.
 
 @item GPG_ERR_NO_DATA
 The OCSP responder returned an ``unknown'' status.  This means that it
 is not aware of the certificate's status.
 
 @item GPG_ERR_NOT_SUPPORTED
 This is commonly seen if OCSP support has not been enabled in the
 configuration.
 @end table
 
 If DirMngr has not enough information about the given certificate (which
 is the case for not yet cached certificates), it will inquire the
 missing data:
 
 @example
   S: INQUIRE SENDCERT <CertID>
   C: D <DER encoded certificate>
   C: END
 @end example
 
 A client should be aware that DirMngr may ask for more than one
 certificate.
 
 If Dirmngr has a certificate but the signature of the certificate
 could not been validated because the root certificate is not known to
 dirmngr as trusted, it may ask back to see whether the client trusts
 this the root certificate:
 
 @example
   S: INQUIRE ISTRUSTED <CertHexfpr>
   C: D 1
   C: END
 @end example
 
 Only this answer will let Dirmngr consider the certificate as valid.
 
 
 @node Dirmngr CHECKCRL
 @subsection Validate a certificate using a CRL
 
 Check whether the certificate with FINGERPRINT (SHA-1 hash of the
 entire X.509 certificate blob) is valid or not by consulting the CRL
 responsible for this certificate.  If the fingerprint has not been
 given or the certificate is not known, the function inquires the
 certificate using:
 
 @example
   S: INQUIRE TARGETCERT
   C: D <DER encoded certificate>
   C: END
 @end example
 
 Thus the caller is expected to return the certificate for the request
 (which should match FINGERPRINT) as a binary blob.  Processing then
 takes place without further interaction; in particular dirmngr tries
 to locate other required certificate by its own mechanism which
 includes a local certificate store as well as a list of trusted root
 certificates.
 
 @noindent
 The return code is 0 for success; i.e. the certificate has not been
 revoked or one of the usual error codes from libgpg-error.
 
 @node Dirmngr CHECKOCSP
 @subsection Validate a certificate using OCSP
 
 @example
   CHECKOCSP [--force-default-responder] [@var{fingerprint}]
 @end example
 
 Check whether the certificate with @var{fingerprint} (the SHA-1 hash of
 the entire X.509 certificate blob) is valid by consulting the appropriate
 OCSP responder.  If the fingerprint has not been given or the
 certificate is not known by Dirmngr, the function inquires the
 certificate using:
 
 @example
   S: INQUIRE TARGETCERT
   C: D <DER encoded certificate>
   C: END
 @end example
 
 Thus the caller is expected to return the certificate for the request
 (which should match @var{fingerprint}) as a binary blob.  Processing
 then takes place without further interaction; in particular dirmngr
 tries to locate other required certificates by its own mechanism which
 includes a local certificate store as well as a list of trusted root
 certificates.
 
 If the option @option{--force-default-responder} is given, only the
 default OCSP responder is used.  This option is the per-command variant
 of the global option @option{--ignore-ocsp-service-url}.
 
 
 @noindent
 The return code is 0 for success; i.e. the certificate has not been
 revoked or one of the usual error codes from libgpg-error.
 
 @node Dirmngr CACHECERT
 @subsection Put a certificate into the internal cache
 
 Put a certificate into the internal cache.  This command might be
 useful if a client knows in advance certificates required for a test and
 wants to make sure they get added to the internal cache.  It is also
 helpful for debugging.  To get the actual certificate, this command
 immediately inquires it using
 
 @example
   S: INQUIRE TARGETCERT
   C: D <DER encoded certificate>
   C: END
 @end example
 
 Thus the caller is expected to return the certificate for the request
 as a binary blob.
 
 @noindent
 The return code is 0 for success; i.e. the certificate has not been
 successfully cached or one of the usual error codes from libgpg-error.
 
 @node Dirmngr VALIDATE
 @subsection Validate a certificate for debugging
 
 Validate a certificate using the certificate validation function used
 internally by dirmngr.  This command is only useful for debugging.  To
 get the actual certificate, this command immediately inquires it using
 
 @example
   S: INQUIRE TARGETCERT
   C: D <DER encoded certificate>
   C: END
 @end example
 
 Thus the caller is expected to return the certificate for the request
 as a binary blob.
 
 
 @mansect see also
 @ifset isman
 @command{gpgsm}(1),
 @command{dirmngr-client}(1)
 @end ifset
 @include see-also-note.texi
 
 @c
 @c !!! UNDER CONSTRUCTION !!!
 @c
 @c
 @c @section Verifying a Certificate
 @c
 @c There are several ways to request services from Dirmngr.  Almost all of
 @c them are done using the Assuan protocol.  What we describe here is the
 @c Assuan command CHECKCRL as used for example by the dirmnr-client tool if
 @c invoked as
 @c
 @c @example
 @c   dirmngr-client foo.crt
 @c @end example
 @c
 @c This command will send an Assuan request to an already running Dirmngr
 @c instance.  foo.crt is expected to be a standard X.509 certificate and
 @c dirmngr will receive the Assuan command
 @c
 @c @example
 @c    CHECKCRL @var [{fingerprint}]
 @c @end example
 @c
 @c @var{fingerprint} is optional and expected to be the SHA-1 has of the
 @c DER encoding of the certificate under question.  It is to be HEX
 @c encoded.  The rationale for sending the fingerprint is that it allows
 @c dirmngr to reply immediately if it has already cached such a request.  If
 @c this is not the case and no certificate has been found in dirmngr's
 @c internal certificate storage, dirmngr will request the certificate using
 @c the Assuan inquiry
 @c
 @c @example
 @c       INQUIRE TARGETCERT
 @c @end example
 @c
 @c The caller (in our example dirmngr-client) is then expected to return
 @c the certificate for the request (which should match @var{fingerprint})
 @c as a binary blob.
 @c
 @c Dirmngr now passes control to @code{crl_cache_cert_isvalid}.  This
 @c function checks whether a CRL item exists for target certificate.  These
 @c CRL items are kept in a database of already loaded and verified CRLs.
 @c This mechanism is called the CRL cache.  Obviously timestamps are kept
 @c there with each item to cope with the expiration date of the CRL.  The
 @c possible return values are: @code{0} to indicate that a valid CRL is
 @c available for the certificate and the certificate itself is not listed
 @c in this CRL, @code{GPG_ERR_CERT_REVOKED} to indicate that the certificate is
 @c listed in the CRL or @code{GPG_ERR_NO_CRL_KNOWN} in cases where no CRL or no
 @c information is available.  The first two codes are immediately returned to
 @c the caller and the processing of this request has been done.
 @c
 @c Only the @code{GPG_ERR_NO_CRL_KNOWN} needs more attention: Dirmngr now
 @c calls @code{clr_cache_reload_crl} and if this succeeds calls
 @c @code{crl_cache_cert_isvald) once more.  All further errors are
 @c immediately returned to the caller.
 @c
 @c @code{crl_cache_reload_crl} is the actual heart of the CRL management.
 @c It locates the corresponding CRL for the target certificate, reads and
 @c verifies this CRL and stores it in the CRL cache.  It works like this:
 @c
 @c * Loop over all crlDPs in the target certificate.
 @c     * If the crlDP is invalid immediately terminate the loop.
 @c     * Loop over all names in the current crlDP.
 @c         * If the URL scheme is unknown or not enabled
 @c           (--ignore-http-dp, --ignore-ldap-dp) continues with
 @c           the next name.
 @c         * @code{crl_fetch} is called to actually retrieve the CRL.
 @c           In case of problems this name is ignore and we continue with
 @c           the next name.  Note that @code{crl_fetch} does only return
 @c           a descriptor for the CRL for further reading so does the CRL
 @c           does not yet end up in memory.
 @c         * @code{crl_cache_insert} is called with that descriptor to
 @c           actually read the CRL into the cache. See below for a
 @c           description of this function.  If there is any error (e.g. read
 @c           problem, CRL not correctly signed or verification of signature
 @c           not possible), this descriptor is rejected and we continue
 @c           with the next name.  If the CRL has been successfully loaded,
 @c           the loop is terminated.
 @c * If no crlDP has been found in the previous loop use a default CRL.
 @c   Note, that if any crlDP has been found but loading of the CRL failed,
 @c   this condition is not true.
 @c     * Try to load a CRL from all configured servers (ldapservers.conf)
 @c       in turn.  The first server returning a CRL is used.
 @c     * @code(crl_cache_insert) is then used to actually insert the CRL
 @c       into the cache.  If this failed we give up immediately without
 @c       checking the rest of the servers from the first step.
 @c * Ready.
 @c
 @c
 @c The @code{crl_cache_insert} function takes care of reading the bulk of
 @c the CRL, parsing it and checking the signature.  It works like this: A
 @c new database file is created using a temporary file name.  The CRL
 @c parsing machinery is started and all items of the CRL are put into
 @c this database file.  At the end the issuer certificate of the CRL
 @c needs to be retrieved.  Three cases are to be distinguished:
 @c
 @c  a) An authorityKeyIdentifier with an issuer and serialno exits: The
 @c     certificate is retrieved using @code{find_cert_bysn}.  If
 @c     the certificate is in the certificate cache, it is directly
 @c     returned. Then the requester (i.e. the client who requested the
 @c     CRL check) is asked via the Assuan inquiry ``SENDCERT'' whether
 @c     he can provide this certificate.  If this succeed the returned
 @c     certificate gets cached and returned.  Note, that dirmngr does not
 @c     verify in any way whether the expected certificate is returned.
 @c     It is in the interest of the client to return a useful certificate
 @c     as otherwise the service request will fail due to a bad signature.
 @c     The last way to get the certificate is by looking it up at
 @c     external resources.  This is done using the @code{ca_cert_fetch}
 @c     and @code{fetch_next_ksba_cert} and comparing the returned
 @c     certificate to match the requested issuer and seriano (This is
 @c     needed because the LDAP layer may return several certificates as
 @c     LDAP as no standard way to retrieve by serial number).
 @c
 @c  b) An authorityKeyIdentifier with a key ID exists: The certificate is
 @c     retrieved using @code{find_cert_bysubject}.  If the certificate is
 @c     in the certificate cache, it is directly returned.  Then the
 @c     requester is asked via the Assuan inquiry ``SENDCERT_SKI'' whether
 @c     he can provide this certificate.  If this succeed the returned
 @c     certificate gets cached and returned.  Note, that dirmngr does not
 @c     verify in any way whether the expected certificate is returned.
 @c     It is in the interest of the client to return a useful certificate
 @c     as otherwise the service request will fail due to a bad signature.
 @c     The last way to get the certificate is by looking it up at
 @c     external resources.  This is done using the @code{ca_cert_fetch}
 @c     and @code{fetch_next_ksba_cert} and comparing the returned
 @c     certificate to match the requested subject and key ID.
 @c
 @c  c) No authorityKeyIdentifier exits: The certificate is retrieved
 @c     using @code{find_cert_bysubject} without the key ID argument.  If
 @c     the certificate is in the certificate cache the first one with a
 @c     matching subject is directly returned.  Then the requester is
 @c     asked via the Assuan inquiry ``SENDCERT'' and an exact
 @c     specification of the subject whether he can
 @c     provide this certificate.  If this succeed the returned
 @c     certificate gets cached and returned.  Note, that dirmngr does not
 @c     verify in any way whether the expected certificate is returned.
 @c     It is in the interest of the client to return a useful certificate
 @c     as otherwise the service request will fail due to a bad signature.
 @c     The last way to get the certificate is by looking it up at
 @c     external resources.  This is done using the @code{ca_cert_fetch}
 @c     and @code{fetch_next_ksba_cert} and comparing the returned
 @c     certificate to match the requested subject; the first certificate
 @c     with a matching subject is then returned.
 @c
 @c If no certificate was found, the function returns with the error
 @c GPG_ERR_MISSING_CERT.  Now the signature is verified.  If this fails,
 @c the erro is returned.  On success the @code{validate_cert_chain} is
 @c used to verify that the certificate is actually valid.
 @c
 @c Here we may encounter a recursive situation:
 @c @code{validate_cert_chain} needs to look at other certificates and
 @c also at CRLs to check whether these other certificates and well, the
 @c CRL issuer certificate itself are not revoked.  FIXME: We need to make
 @c sure that @code{validate_cert_chain} does not try to lookup the CRL we
 @c are currently processing. This would be a catch-22 and may indicate a
 @c broken PKI.  However, due to overlapping expiring times and imprecise
 @c clocks this may actually happen.
 @c
 @c For historical reasons the Assuan command ISVALID is a bit different
 @c to CHECKCRL but this is mainly due to different calling conventions.
 @c In the end the same fucntionality is used, albeit hidden by a couple
 @c of indirection and argument and result code mangling.  It furthere
 @c ingetrages OCSP checking depending on options are the way it is
 @c called.  GPGSM still uses this command but might eventuall switch over
 @c to CHECKCRL and CHECKOCSP so that ISVALID can be retired.
 @c
 @c
 @c @section Validating a certificate
 @c
 @c We describe here how the internal function @code{validate_cert_chain}
 @c works. Note that mainly testing purposes this functionality may be
 @c called directly using @cmd{dirmngr-client --validate @file{foo.crt}}.
 @c
 @c The function takes the target certificate and a mode argument as
 @c parameters and returns an error code and optionally the closes
 @c expiration time of all certificates in the chain.
 @c
 @c We first check that the certificate may be used for the requested
 @c purpose (i.e. OCSP or CRL signing).  If this is not the case
 @c GPG_ERR_WRONG_KEY_USAGE is returned.
 @c
 @c The next step is to find the trust anchor (root certificate) and to
 @c assemble the chain in memory: Starting with the target certificate,
 @c the expiration time is checked against the current date, unknown
 @c critical extensions are detected and certificate policies are matched
 @c (We only allow 2.289.9.9 but I have no clue about that OID and from
 @c where I got it - it does not even seem to be assigned - debug cruft?).
 @c
 @c Now if this certificate is a self-signed one, we have reached the
 @c trust anchor.  In this case we check that the signature is good, the
 @c certificate is allowed to act as a CA, that it is a trusted one (by
 @c checking whether it is has been put into the trusted-certs
 @c configuration directory) and finally prepend into to our list
 @c representing the certificate chain.  This steps ends then.
 @c
 @c If it is not a self-signed certificate, we check that the chain won't
 @c get too long (current limit is 100), if this is the case we terminate
 @c with the error GPG_ERR_BAD_CERT_CHAIN.
 @c
 @c Now the issuer's certificate is looked up: If an
 @c authorityKeyIdentifier is available, this one is used to locate the
 @c certificate either using issuer and serialnumber or subject DN
 @c (i.e. the issuer's DN) and the keyID.  The functions
 @c @code{find_cert_bysn) and @code{find_cert_bysubject} are used
 @c respectively. The have already been described above under the
 @c description of @code{crl_cache_insert}.  If no certificate was found
 @c or with no authorityKeyIdentifier, only the cache is consulted using
 @c @code{get_cert_bysubject}.  The latter is done under the assumption
 @c that a matching certificate has explicitly been put into the
 @c certificate cache.  If the issuer's certificate could not be found,
 @c the validation terminates with the error code @code{GPG_ERR_MISSING_CERT}.
 @c
 @c If the issuer's certificate has been found, the signature of the
 @c actual certificate is checked and in case this fails the error
 @c #code{GPG_ERR_BAD_CERT_CHAIN} is returned.  If the signature checks out, the
 @c maximum chain length of the issuing certificate is checked as well as
 @c the capability of the certificate (i.e. whether he may be used for
 @c certificate signing).  Then the certificate is prepended to our list
 @c representing the certificate chain.  Finally the loop is continued now
 @c with the issuer's certificate as the current certificate.
 @c
 @c After the end of the loop and if no error as been encountered
 @c (i.e. the certificate chain has been assempled correctly), a check is
 @c done whether any certificate expired or a critical policy has not been
 @c met.  In any of these cases the validation terminates with an
 @c appropriate error.
 @c
 @c Finally the function @code{check_revocations} is called to verify no
 @c certificate in the assempled chain has been revoked: This is an
 @c recursive process because a CRL has to be checked for each certificate
 @c in the chain except for the root certificate, of which we already know
 @c that it is trusted and we avoid checking a CRL here due to common
 @c setup problems and the assumption that a revoked root certificate has
 @c been removed from the list of trusted certificates.
 @c
 @c
 @c
 @c
 @c @section Looking up certificates through LDAP.
 @c
 @c This describes the LDAP layer to retrieve certificates.
 @c the functions @code{ca_cert_fetch} and @code{fetch_next_ksba_cert} are
 @c used for this.  The first one starts a search and the second one is
 @c used to retrieve certificate after certificate.
 @c