diff --git a/g10/key-clean.c b/g10/key-clean.c index 9320428c8..c8a6efe50 100644 --- a/g10/key-clean.c +++ b/g10/key-clean.c @@ -1,614 +1,622 @@ /* key-clean.c - Functions to clean a keyblock * Copyright (C) 1998-2008, 2010-2011 Free Software Foundation, Inc. * Copyright (C) 2014, 2016-2018 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 . * SPDX-License-Identifier: GPL-3.0-or-later */ #include #include #include #include #include "gpg.h" #include "keydb.h" #include "../common/util.h" #include "../common/host2net.h" #include "../common/i18n.h" #include "options.h" #include "packet.h" #include "main.h" #include "key-clean.h" +#define NF_USABLE 8 /* Usable signature and not a revocation. */ +#define NF_CONSIDER 9 /* Internal use. */ +#define NF_PROCESSED 10 /* Internal use. */ +#define NF_REVOC 11 /* Usable revocation. */ +#define NF_NOKEY 12 /* Key not available. */ + /* * Mark the signature of the given UID which are used to certify it. * To do this, we first remove all signatures which are not valid and * from the remaining we look for the latest one. If this is not a * certification revocation signature we mark the signature by setting - * node flag bit 8. Revocations are marked with flag 11, and sigs - * from unavailable keys are marked with flag 12. Note that flag bits - * 9 and 10 are used for internal purposes. + * node flag bit NF_USABLE. Revocations are marked with NF_REVOC, and + * sigs from unavailable keys are marked with NF_NOKEY. */ void mark_usable_uid_certs (ctrl_t ctrl, kbnode_t keyblock, kbnode_t uidnode, u32 *main_kid, struct key_item *klist, u32 curtime, u32 *next_expire) { kbnode_t node; PKT_signature *sig; /* First check all signatures. */ for (node=uidnode->next; node; node = node->next) { int rc; - node->flag &= ~(1<<8 | 1<<9 | 1<<10 | 1<<11 | 1<<12); + node->flag &= ~(1<pkt->pkttype == PKT_USER_ID || node->pkt->pkttype == PKT_PUBLIC_SUBKEY || node->pkt->pkttype == PKT_SECRET_SUBKEY) break; /* ready */ if (node->pkt->pkttype != PKT_SIGNATURE) continue; sig = node->pkt->pkt.signature; if (main_kid && sig->keyid[0] == main_kid[0] && sig->keyid[1] == main_kid[1]) continue; /* ignore self-signatures if we pass in a main_kid */ if (!IS_UID_SIG(sig) && !IS_UID_REV(sig)) continue; /* we only look at these signature classes */ if(sig->sig_class>=0x11 && sig->sig_class<=0x13 && sig->sig_class-0x10flag |= 1<<12; + node->flag |= 1<flag |= 1<<9; + node->flag |= 1<next) - node->flag &= ~(1<<8 | 1<<9 | 1<<10 | 1<<11 | 1<<12); + node->flag &= ~(1<next; node; node = node->next) { KBNODE n, signode; u32 kid[2]; u32 sigdate; if (node->pkt->pkttype == PKT_PUBLIC_SUBKEY || node->pkt->pkttype == PKT_SECRET_SUBKEY) break; - if ( !(node->flag & (1<<9)) ) + if ( !(node->flag & (1<flag & (1<<10)) ) + if ( (node->flag & (1<flag |= (1<<10); /* mark this node as processed */ + node->flag |= (1<pkt->pkt.signature; signode = node; sigdate = sig->timestamp; kid[0] = sig->keyid[0]; kid[1] = sig->keyid[1]; /* Now find the latest and greatest signature */ for (n=uidnode->next; n; n = n->next) { if (n->pkt->pkttype == PKT_PUBLIC_SUBKEY || n->pkt->pkttype == PKT_SECRET_SUBKEY) break; - if ( !(n->flag & (1<<9)) ) + if ( !(n->flag & (1<flag & (1<<10)) ) + if ( (n->flag & (1<pkt->pkt.signature; if (kid[0] != sig->keyid[0] || kid[1] != sig->keyid[1]) continue; - n->flag |= (1<<10); /* mark this node as processed */ + n->flag |= (1<pkt->pkt.signature) && !signode->pkt->pkt.signature->flags.revocable && (signode->pkt->pkt.signature->expiredate==0 || signode->pkt->pkt.signature->expiredate>curtime))) && (!(IS_UID_SIG(n->pkt->pkt.signature) && !n->pkt->pkt.signature->flags.revocable && (n->pkt->pkt.signature->expiredate==0 || n->pkt->pkt.signature->expiredate>curtime)))) continue; /* If n is nonrevocable and unexpired and signode isn't, then take n. Again, it doesn't matter which is older: if n was older then we don't want to take signode as n is nonrevocable. If signode was older then we're automatically fine. */ if((!(IS_UID_SIG(signode->pkt->pkt.signature) && !signode->pkt->pkt.signature->flags.revocable && (signode->pkt->pkt.signature->expiredate==0 || signode->pkt->pkt.signature->expiredate>curtime))) && ((IS_UID_SIG(n->pkt->pkt.signature) && !n->pkt->pkt.signature->flags.revocable && (n->pkt->pkt.signature->expiredate==0 || n->pkt->pkt.signature->expiredate>curtime)))) { signode = n; sigdate = sig->timestamp; continue; } /* At this point, if it's newer, it goes in as the only remaining possibilities are signode and n are both either revocable or expired or both nonrevocable and unexpired. If the timestamps are equal take the later ordered packet, presuming that the key packets are hopefully in their original order. */ if (sig->timestamp >= sigdate) { signode = n; sigdate = sig->timestamp; } } sig = signode->pkt->pkt.signature; if (IS_UID_SIG (sig)) { /* this seems to be a usable one which is not revoked. * Just need to check whether there is an expiration time, * We do the expired certification after finding a suitable * certification, the assumption is that a signator does not * want that after the expiration of his certificate the * system falls back to an older certification which has a * different expiration time */ const byte *p; u32 expire; p = parse_sig_subpkt (sig, 1, SIGSUBPKT_SIG_EXPIRE, NULL ); expire = p? sig->timestamp + buf32_to_u32(p) : 0; if (expire==0 || expire > curtime ) { - signode->flag |= (1<<8); /* yeah, found a good cert */ + signode->flag |= (1<flag |= (1<<11); + signode->flag |= (1<pkt->pkttype == PKT_PUBLIC_KEY || keyblock->pkt->pkttype == PKT_SECRET_KEY); keyid_from_pk (keyblock->pkt->pkt.public_key, keyid); /* Passing in a 0 for current time here means that we'll never weed out an expired sig. This is correct behavior since we want to keep the most recent expired sig in a series. */ mark_usable_uid_certs (ctrl, keyblock, uidnode, NULL, NULL, 0, NULL); /* What we want to do here is remove signatures that are not considered as part of the trust calculations. Thus, all invalid signatures are out, as are any signatures that aren't the last of a series of uid sigs or revocations It breaks down like this: coming out of mark_usable_uid_certs, if a sig is unflagged, it is - not even a candidate. If a sig has flag 9 or 10, that means it - was selected as a candidate and vetted. If a sig has flag 8 it - is a usable signature. If a sig has flag 11 it is a usable - revocation. If a sig has flag 12 it was issued by an unavailable - key. "Usable" here means the most recent valid - signature/revocation in a series from a particular signer. + not even a candidate. If a sig has flag NF_CONSIDER or + NF_PROCESSED, that means it was selected as a candidate and + vetted. If a sig has flag NF_USABLE it is a usable signature. + If a sig has flag NF_REVOC it is a usable revocation. If a sig + has flag NF_NOKEY it was issued by an unavailable key. "Usable" + here means the most recent valid signature/revocation in a series + from a particular signer. Delete everything that isn't a usable uid sig (which might be expired), a usable revocation, or a sig from an unavailable key. */ for (node=uidnode->next; node && node->pkt->pkttype==PKT_SIGNATURE; node=node->next) { int keep; keep = self_only? (node->pkt->pkt.signature->keyid[0] == keyid[0] && node->pkt->pkt.signature->keyid[1] == keyid[1]) : 1; /* Keep usable uid sigs ... */ - if ((node->flag & (1<<8)) && keep) + if ((node->flag & (1<flag & (1<<11)) && keep) + if ((node->flag & (1<flag & (1<<12)) + if(node->flag & (1<pkt->pkt.signature->keyid), uidnode->pkt->pkt.user_id->name, - node->flag&(1<<12)? "key unavailable": - node->flag&(1<<9)? "signature superseded" - /* */ :"invalid signature" ); + node->flag&(1<flag&(1<pkt->pkt.user_id; int deleted = 0; log_assert (keyblock->pkt->pkttype == PKT_PUBLIC_KEY || keyblock->pkt->pkttype == PKT_SECRET_KEY); log_assert (uidnode->pkt->pkttype==PKT_USER_ID); /* Skip valid user IDs, compacted user IDs, and non-self-signed user IDs if --allow-non-selfsigned-uid is set. */ if (uid->created || uid->flags.compacted || (!uid->flags.expired && !uid->flags.revoked && opt.allow_non_selfsigned_uid)) return 0; for (node=uidnode->next; node && node->pkt->pkttype == PKT_SIGNATURE; node=node->next) { if (!node->pkt->pkt.signature->flags.chosen_selfsig) { delete_kbnode (node); deleted = 1; uidnode->pkt->pkt.user_id->flags.compacted = 1; } } if (noisy) { const char *reason; char *user = utf8_to_native (uid->name, uid->len, 0); if (uid->flags.revoked) reason = _("revoked"); else if (uid->flags.expired) reason = _("expired"); else reason = _("invalid"); log_info ("compacting user ID \"%s\" on key %s: %s\n", user, keystr_from_pk (keyblock->pkt->pkt.public_key), reason); xfree (user); } return deleted; } /* Needs to be called after a merge_keys_and_selfsig() */ void clean_one_uid (ctrl_t ctrl, kbnode_t keyblock, kbnode_t uidnode, int noisy, int self_only, int *uids_cleaned, int *sigs_cleaned) { int dummy = 0; log_assert (keyblock->pkt->pkttype == PKT_PUBLIC_KEY || keyblock->pkt->pkttype == PKT_SECRET_KEY); log_assert (uidnode->pkt->pkttype==PKT_USER_ID); if (!uids_cleaned) uids_cleaned = &dummy; if (!sigs_cleaned) sigs_cleaned = &dummy; /* Do clean_uid_from_key first since if it fires off, we don't have to bother with the other. */ *uids_cleaned += clean_uid_from_key (keyblock, uidnode, noisy); if (!uidnode->pkt->pkt.user_id->flags.compacted) *sigs_cleaned += clean_sigs_from_uid (ctrl, keyblock, uidnode, noisy, self_only); } /* NB: This function marks the deleted nodes only and the caller is * responsible to skip or remove them. Needs to be called after a * merge_keys_and_selfsig(). */ void clean_all_uids (ctrl_t ctrl, kbnode_t keyblock, int noisy, int self_only, int *uids_cleaned, int *sigs_cleaned) { kbnode_t node; for (node = keyblock->next; node && !(node->pkt->pkttype == PKT_PUBLIC_SUBKEY || node->pkt->pkttype == PKT_SECRET_SUBKEY); node = node->next) { if (node->pkt->pkttype == PKT_USER_ID) clean_one_uid (ctrl, keyblock, node, noisy, self_only, uids_cleaned, sigs_cleaned); } /* Remove bogus subkey binding signatures: The only signatures * allowed are of class 0x18 and 0x28. */ log_assert (!node || (node->pkt->pkttype == PKT_PUBLIC_SUBKEY || node->pkt->pkttype == PKT_SECRET_SUBKEY)); } /* Helper for clean_all_subkeys. */ static int clean_one_subkey (ctrl_t ctrl, kbnode_t subkeynode, int noisy, int clean_level) { kbnode_t node; PKT_public_key *pk = subkeynode->pkt->pkt.public_key; unsigned int use = pk->pubkey_usage; int do_clean = 0; (void)ctrl; (void)noisy; log_assert (subkeynode->pkt->pkttype == PKT_PUBLIC_SUBKEY || subkeynode->pkt->pkttype == PKT_SECRET_SUBKEY); if (DBG_LOOKUP) log_debug ("\tchecking subkey %08lX [%c%c%c%c%c]\n", (ulong) keyid_from_pk (pk, NULL), (use & PUBKEY_USAGE_ENC)? 'e':'-', (use & PUBKEY_USAGE_SIG)? 's':'-', (use & PUBKEY_USAGE_CERT)? 'c':'-', (use & PUBKEY_USAGE_AUTH)? 'a':'-', (use & PUBKEY_USAGE_UNKNOWN)? '?':'-'); if (!pk->flags.valid) { if (DBG_LOOKUP) log_debug ("\tsubkey not valid\n"); if (clean_level == KEY_CLEAN_INVALID) do_clean = 1; } if (pk->has_expired) { if (DBG_LOOKUP) log_debug ("\tsubkey has expired\n"); if (clean_level == KEY_CLEAN_ALL) do_clean = 1; else if (clean_level == KEY_CLEAN_AUTHENCR && (use & (PUBKEY_USAGE_ENC | PUBKEY_USAGE_AUTH)) && !(use & (PUBKEY_USAGE_SIG | PUBKEY_USAGE_CERT))) do_clean = 1; else if (clean_level == KEY_CLEAN_ENCR && (use & PUBKEY_USAGE_ENC) && !(use & (PUBKEY_USAGE_SIG | PUBKEY_USAGE_CERT | PUBKEY_USAGE_AUTH))) do_clean = 1; } if (pk->flags.revoked) { if (DBG_LOOKUP) log_debug ("\tsubkey has been revoked (keeping)\n"); /* Avoid any cleaning because revocations are important. */ do_clean = 0; } if (!do_clean) return 0; if (DBG_LOOKUP) log_debug ("\t=> removing this subkey\n"); delete_kbnode (subkeynode); for (node = subkeynode->next; node && !(node->pkt->pkttype == PKT_PUBLIC_SUBKEY || node->pkt->pkttype == PKT_SECRET_SUBKEY); node = node->next) delete_kbnode (node); return 1; } /* Helper for clean_all_subkeys. Here duplicate signatures from a * subkey are removed. This should in general not happen because * import takes care of that. However, sometimes other tools are used * to manage a keyring or key has been imported a long time ago. */ static int clean_one_subkey_dupsigs (ctrl_t ctrl, kbnode_t subkeynode) { kbnode_t node; PKT_public_key *pk = subkeynode->pkt->pkt.public_key; int any_choosen = 0; int count = 0; (void)ctrl; log_assert (subkeynode->pkt->pkttype == PKT_PUBLIC_SUBKEY || subkeynode->pkt->pkttype == PKT_SECRET_SUBKEY); if (DBG_LOOKUP) log_debug ("\tchecking subkey %08lX for dupsigs\n", (ulong) keyid_from_pk (pk, NULL)); /* First check that the chosen flag has been set. Note that we * only look at plain signatures so to keep all revocation * signatures which may carry important information. */ for (node = subkeynode->next; node && !(node->pkt->pkttype == PKT_PUBLIC_SUBKEY || node->pkt->pkttype == PKT_SECRET_SUBKEY); node = node->next) { if (!is_deleted_kbnode (node) && node->pkt->pkttype == PKT_SIGNATURE && IS_SUBKEY_SIG (node->pkt->pkt.signature) && node->pkt->pkt.signature->flags.chosen_selfsig) { any_choosen = 1; break; } } if (!any_choosen) return 0; /* Ooops no chosen flag set - we can't decide. */ for (node = subkeynode->next; node && !(node->pkt->pkttype == PKT_PUBLIC_SUBKEY || node->pkt->pkttype == PKT_SECRET_SUBKEY); node = node->next) { if (!is_deleted_kbnode (node) && node->pkt->pkttype == PKT_SIGNATURE && IS_SUBKEY_SIG (node->pkt->pkt.signature) && !node->pkt->pkt.signature->flags.chosen_selfsig) { delete_kbnode (node); count++; } } return count; } /* This function only marks the deleted nodes and the caller is * responsible to skip or remove them. Needs to be called after a * merge_keys_and_selfsig. CLEAN_LEVEL is one of the KEY_CLEAN_* * values. */ void clean_all_subkeys (ctrl_t ctrl, kbnode_t keyblock, int noisy, int clean_level, int *subkeys_cleaned, int *sigs_cleaned) { kbnode_t first_subkey, node; int n; if (DBG_LOOKUP) log_debug ("clean_all_subkeys: checking key %08lX\n", (ulong) keyid_from_pk (keyblock->pkt->pkt.public_key, NULL)); for (node = keyblock->next; node; node = node->next) if (!is_deleted_kbnode (node) && (node->pkt->pkttype == PKT_PUBLIC_SUBKEY || node->pkt->pkttype == PKT_SECRET_SUBKEY)) break; first_subkey = node; /* Remove bogus subkey binding signatures: The only signatures * allowed are of class 0x18 and 0x28. */ for (node = first_subkey; node; node = node->next) { if (is_deleted_kbnode (node)) continue; if (node->pkt->pkttype == PKT_SIGNATURE && !(IS_SUBKEY_SIG (node->pkt->pkt.signature) || IS_SUBKEY_REV (node->pkt->pkt.signature))) { delete_kbnode (node); if (sigs_cleaned) ++*sigs_cleaned; } } /* Do the selected cleaning. */ if (clean_level > KEY_CLEAN_NONE) { /* Clean enitre subkeys. */ for (node = first_subkey; node; node = node->next) { if (is_deleted_kbnode (node)) continue; if (node->pkt->pkttype == PKT_PUBLIC_SUBKEY || node->pkt->pkttype == PKT_SECRET_SUBKEY) { if (clean_one_subkey (ctrl, node, noisy, clean_level)) { if (subkeys_cleaned) ++*subkeys_cleaned; } } } /* Clean duplicate signatures from a subkey. */ for (node = first_subkey; node; node = node->next) { if (is_deleted_kbnode (node)) continue; if (node->pkt->pkttype == PKT_PUBLIC_SUBKEY || node->pkt->pkttype == PKT_SECRET_SUBKEY) { n = clean_one_subkey_dupsigs (ctrl, node); if (sigs_cleaned) *sigs_cleaned += n; } } } }