1 /* trust.c - High level trust functions
2 * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
3 * 2008, 2012 Free Software Foundation, Inc.
4 * Copyright (C) 2014 Werner Koch
6 * This file is part of GnuPG.
8 * GnuPG is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 3 of the License, or
11 * (at your option) any later version.
13 * GnuPG is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, see <https://www.gnu.org/licenses/>.
38 /* Return true if key is disabled. Note that this is usually used via
39 the pk_is_disabled macro. */
41 cache_disabled_value (PKT_public_key *pk)
43 #ifdef NO_TRUST_MODELS
47 return tdb_cache_disabled_value (pk);
53 register_trusted_keyid (u32 *keyid)
55 #ifdef NO_TRUST_MODELS
58 tdb_register_trusted_keyid (keyid);
64 register_trusted_key (const char *string)
66 #ifdef NO_TRUST_MODELS
69 tdb_register_trusted_key (string);
76 * This function returns a letter for a trust value. Trust flags
80 trust_letter (unsigned int value)
82 switch( (value & TRUST_MASK) )
84 case TRUST_UNKNOWN: return '-';
85 case TRUST_EXPIRED: return 'e';
86 case TRUST_UNDEFINED: return 'q';
87 case TRUST_NEVER: return 'n';
88 case TRUST_MARGINAL: return 'm';
89 case TRUST_FULLY: return 'f';
90 case TRUST_ULTIMATE: return 'u';
96 /* The strings here are similar to those in
97 pkclist.c:do_edit_ownertrust() */
99 trust_value_to_string (unsigned int value)
101 switch ((value & TRUST_MASK))
103 case TRUST_UNKNOWN: return _("unknown");
104 case TRUST_EXPIRED: return _("expired");
105 case TRUST_UNDEFINED: return _("undefined");
106 case TRUST_NEVER: return _("never");
107 case TRUST_MARGINAL: return _("marginal");
108 case TRUST_FULLY: return _("full");
109 case TRUST_ULTIMATE: return _("ultimate");
110 default: return "err";
116 string_to_trust_value (const char *str)
118 if (!ascii_strcasecmp (str, "undefined"))
119 return TRUST_UNDEFINED;
120 else if (!ascii_strcasecmp (str, "never"))
122 else if (!ascii_strcasecmp (str, "marginal"))
123 return TRUST_MARGINAL;
124 else if (!ascii_strcasecmp (str, "full"))
126 else if (!ascii_strcasecmp(str, "ultimate"))
127 return TRUST_ULTIMATE;
134 uid_trust_string_fixed (ctrl_t ctrl, PKT_public_key *key, PKT_user_id *uid)
138 /* TRANSLATORS: these strings are similar to those in
139 trust_value_to_string(), but are a fixed length. This is needed to
140 make attractive information listings where columns line up
141 properly. The value "10" should be the length of the strings you
142 choose to translate to. This is the length in printable columns.
143 It gets passed to atoi() so everything after the number is
144 essentially a comment and need not be translated. Either key and
145 uid are both NULL, or neither are NULL. */
146 return _("10 translator see trust.c:uid_trust_string_fixed");
148 else if(uid->is_revoked || (key && key->flags.revoked))
149 return _("[ revoked]");
150 else if(uid->is_expired)
151 return _("[ expired]");
154 switch (get_validity (ctrl, key, uid, NULL, 0) & TRUST_MASK)
156 case TRUST_UNKNOWN: return _("[ unknown]");
157 case TRUST_EXPIRED: return _("[ expired]");
158 case TRUST_UNDEFINED: return _("[ undef ]");
159 case TRUST_NEVER: return _("[ never ]");
160 case TRUST_MARGINAL: return _("[marginal]");
161 case TRUST_FULLY: return _("[ full ]");
162 case TRUST_ULTIMATE: return _("[ultimate]");
172 * Return the assigned ownertrust value for the given public key.
173 * The key should be the primary key.
176 get_ownertrust (PKT_public_key *pk)
178 #ifdef NO_TRUST_MODELS
180 return TRUST_UNKNOWN;
182 return tdb_get_ownertrust (pk);
188 * Same as get_ownertrust but this takes the minimum ownertrust value
189 * into into account, and will bump up the value as needed.
192 get_ownertrust_with_min (PKT_public_key *pk)
194 #ifdef NO_TRUST_MODELS
196 return TRUST_UNKNOWN;
198 unsigned int otrust, otrust_min;
200 otrust = (tdb_get_ownertrust (pk) & TRUST_MASK);
201 otrust_min = tdb_get_min_ownertrust (pk);
202 if (otrust < otrust_min)
204 /* If the trust that the user has set is less than the trust
205 that was calculated from a trust signature chain, use the
206 higher of the two. We do this here and not in
207 get_ownertrust since the underlying ownertrust should not
208 really be set - just the appearance of the ownertrust. */
219 * Same as get_ownertrust but return a trust letter instead of an
220 * value. This takes the minimum ownertrust value into account.
223 get_ownertrust_info (PKT_public_key *pk)
225 return trust_letter (get_ownertrust_with_min (pk));
230 * Same as get_ownertrust but return a trust string instead of an
231 * value. This takes the minimum ownertrust value into account.
234 get_ownertrust_string (PKT_public_key *pk)
236 return trust_value_to_string (get_ownertrust_with_min (pk));
241 * Set the trust value of the given public key to the new value.
242 * The key should be a primary one.
245 update_ownertrust (PKT_public_key *pk, unsigned int new_trust)
247 #ifdef NO_TRUST_MODELS
251 tdb_update_ownertrust (pk, new_trust);
257 clear_ownertrusts (PKT_public_key *pk)
259 #ifdef NO_TRUST_MODELS
263 return tdb_clear_ownertrusts (pk);
269 revalidation_mark (void)
271 #ifndef NO_TRUST_MODELS
272 tdb_revalidation_mark ();
278 check_trustdb_stale (ctrl_t ctrl)
280 #ifndef NO_TRUST_MODELS
281 tdb_check_trustdb_stale (ctrl);
289 check_or_update_trustdb (ctrl_t ctrl)
291 #ifndef NO_TRUST_MODELS
292 tdb_check_or_update (ctrl);
300 * Return the validity information for PK. If the namehash is not
301 * NULL, the validity of the corresponding user ID is returned,
302 * otherwise, a reasonable value for the entire key is returned.
305 get_validity (ctrl_t ctrl, PKT_public_key *pk, PKT_user_id *uid,
306 PKT_signature *sig, int may_ask)
309 unsigned int validity;
311 PKT_public_key *main_pk;
314 namehash_from_uid (uid);
316 keyid_from_pk (pk, kid);
317 if (pk->main_keyid[0] != kid[0] || pk->main_keyid[1] != kid[1])
319 /* This is a subkey - get the mainkey. */
320 main_pk = xmalloc_clear (sizeof *main_pk);
321 rc = get_pubkey (main_pk, pk->main_keyid);
324 char *tempkeystr = xstrdup (keystr (pk->main_keyid));
325 log_error ("error getting main key %s of subkey %s: %s\n",
326 tempkeystr, keystr (kid), gpg_strerror (rc));
328 validity = TRUST_UNKNOWN;
335 #ifdef NO_TRUST_MODELS
336 validity = TRUST_UNKNOWN;
338 validity = tdb_get_validity_core (ctrl, pk, uid, main_pk, sig, may_ask);
342 /* Set some flags direct from the key */
343 if (main_pk->flags.revoked)
344 validity |= TRUST_FLAG_REVOKED;
345 if (main_pk != pk && pk->flags.revoked)
346 validity |= TRUST_FLAG_SUB_REVOKED;
347 /* Note: expiration is a trust value and not a flag - don't know why
348 * I initially designed it that way. */
349 if (main_pk->has_expired || pk->has_expired)
350 validity = ((validity & (~TRUST_MASK | TRUST_FLAG_PENDING_CHECK))
354 free_public_key (main_pk);
360 get_validity_info (ctrl_t ctrl, PKT_public_key *pk, PKT_user_id *uid)
365 return '?'; /* Just in case a NULL PK is passed. */
367 trustlevel = get_validity (ctrl, pk, uid, NULL, 0);
368 if ((trustlevel & TRUST_FLAG_REVOKED))
370 return trust_letter (trustlevel);
375 get_validity_string (ctrl_t ctrl, PKT_public_key *pk, PKT_user_id *uid)
380 return "err"; /* Just in case a NULL PK is passed. */
382 trustlevel = get_validity (ctrl, pk, uid, NULL, 0);
383 if ((trustlevel & TRUST_FLAG_REVOKED))
385 return trust_value_to_string (trustlevel);
391 * Mark the signature of the given UID which are used to certify it.
392 * To do this, we first revmove all signatures which are not valid and
393 * from the remain ones we look for the latest one. If this is not a
394 * certification revocation signature we mark the signature by setting
395 * node flag bit 8. Revocations are marked with flag 11, and sigs
396 * from unavailable keys are marked with flag 12. Note that flag bits
397 * 9 and 10 are used for internal purposes.
400 mark_usable_uid_certs (kbnode_t keyblock, kbnode_t uidnode,
401 u32 *main_kid, struct key_item *klist,
402 u32 curtime, u32 *next_expire)
407 /* First check all signatures. */
408 for (node=uidnode->next; node; node = node->next)
412 node->flag &= ~(1<<8 | 1<<9 | 1<<10 | 1<<11 | 1<<12);
413 if (node->pkt->pkttype == PKT_USER_ID
414 || node->pkt->pkttype == PKT_PUBLIC_SUBKEY)
416 if (node->pkt->pkttype != PKT_SIGNATURE)
418 sig = node->pkt->pkt.signature;
420 && sig->keyid[0] == main_kid[0] && sig->keyid[1] == main_kid[1])
421 continue; /* ignore self-signatures if we pass in a main_kid */
422 if (!IS_UID_SIG(sig) && !IS_UID_REV(sig))
423 continue; /* we only look at these signature classes */
424 if(sig->sig_class>=0x11 && sig->sig_class<=0x13 &&
425 sig->sig_class-0x10<opt.min_cert_level)
426 continue; /* treat anything under our min_cert_level as an
428 if (klist && !is_in_klist (klist, sig))
429 continue; /* no need to check it then */
430 if ((rc=check_key_signature (keyblock, node, NULL)))
432 /* we ignore anything that won't verify, but tag the
434 if (gpg_err_code (rc) == GPG_ERR_NO_PUBKEY)
440 /* Reset the remaining flags. */
441 for (; node; node = node->next)
442 node->flag &= ~(1<<8 | 1<<9 | 1<<10 | 1<<11 | 1<<12);
444 /* kbnode flag usage: bit 9 is here set for signatures to consider,
445 * bit 10 will be set by the loop to keep track of keyIDs already
446 * processed, bit 8 will be set for the usable signatures, and bit
447 * 11 will be set for usable revocations. */
449 /* For each cert figure out the latest valid one. */
450 for (node=uidnode->next; node; node = node->next)
456 if (node->pkt->pkttype == PKT_PUBLIC_SUBKEY)
458 if ( !(node->flag & (1<<9)) )
459 continue; /* not a node to look at */
460 if ( (node->flag & (1<<10)) )
461 continue; /* signature with a keyID already processed */
462 node->flag |= (1<<10); /* mark this node as processed */
463 sig = node->pkt->pkt.signature;
465 sigdate = sig->timestamp;
466 kid[0] = sig->keyid[0]; kid[1] = sig->keyid[1];
468 /* Now find the latest and greatest signature */
469 for (n=uidnode->next; n; n = n->next)
471 if (n->pkt->pkttype == PKT_PUBLIC_SUBKEY)
473 if ( !(n->flag & (1<<9)) )
475 if ( (n->flag & (1<<10)) )
476 continue; /* shortcut already processed signatures */
477 sig = n->pkt->pkt.signature;
478 if (kid[0] != sig->keyid[0] || kid[1] != sig->keyid[1])
480 n->flag |= (1<<10); /* mark this node as processed */
482 /* If signode is nonrevocable and unexpired and n isn't,
483 then take signode (skip). It doesn't matter which is
484 older: if signode was older then we don't want to take n
485 as signode is nonrevocable. If n was older then we're
486 automatically fine. */
488 if(((IS_UID_SIG(signode->pkt->pkt.signature) &&
489 !signode->pkt->pkt.signature->flags.revocable &&
490 (signode->pkt->pkt.signature->expiredate==0 ||
491 signode->pkt->pkt.signature->expiredate>curtime))) &&
492 (!(IS_UID_SIG(n->pkt->pkt.signature) &&
493 !n->pkt->pkt.signature->flags.revocable &&
494 (n->pkt->pkt.signature->expiredate==0 ||
495 n->pkt->pkt.signature->expiredate>curtime))))
498 /* If n is nonrevocable and unexpired and signode isn't,
499 then take n. Again, it doesn't matter which is older: if
500 n was older then we don't want to take signode as n is
501 nonrevocable. If signode was older then we're
502 automatically fine. */
504 if((!(IS_UID_SIG(signode->pkt->pkt.signature) &&
505 !signode->pkt->pkt.signature->flags.revocable &&
506 (signode->pkt->pkt.signature->expiredate==0 ||
507 signode->pkt->pkt.signature->expiredate>curtime))) &&
508 ((IS_UID_SIG(n->pkt->pkt.signature) &&
509 !n->pkt->pkt.signature->flags.revocable &&
510 (n->pkt->pkt.signature->expiredate==0 ||
511 n->pkt->pkt.signature->expiredate>curtime))))
514 sigdate = sig->timestamp;
518 /* At this point, if it's newer, it goes in as the only
519 remaining possibilities are signode and n are both either
520 revocable or expired or both nonrevocable and unexpired.
521 If the timestamps are equal take the later ordered
522 packet, presuming that the key packets are hopefully in
523 their original order. */
525 if (sig->timestamp >= sigdate)
528 sigdate = sig->timestamp;
532 sig = signode->pkt->pkt.signature;
533 if (IS_UID_SIG (sig))
534 { /* this seems to be a usable one which is not revoked.
535 * Just need to check whether there is an expiration time,
536 * We do the expired certification after finding a suitable
537 * certification, the assumption is that a signator does not
538 * want that after the expiration of his certificate the
539 * system falls back to an older certification which has a
540 * different expiration time */
544 p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_SIG_EXPIRE, NULL );
545 expire = p? sig->timestamp + buf32_to_u32(p) : 0;
547 if (expire==0 || expire > curtime )
549 signode->flag |= (1<<8); /* yeah, found a good cert */
550 if (next_expire && expire && expire < *next_expire)
551 *next_expire = expire;
555 signode->flag |= (1<<11);
561 clean_sigs_from_uid (kbnode_t keyblock, kbnode_t uidnode,
562 int noisy, int self_only)
568 log_assert (keyblock->pkt->pkttype==PKT_PUBLIC_KEY);
570 keyid_from_pk (keyblock->pkt->pkt.public_key, keyid);
572 /* Passing in a 0 for current time here means that we'll never weed
573 out an expired sig. This is correct behavior since we want to
574 keep the most recent expired sig in a series. */
575 mark_usable_uid_certs (keyblock, uidnode, NULL, NULL, 0, NULL);
577 /* What we want to do here is remove signatures that are not
578 considered as part of the trust calculations. Thus, all invalid
579 signatures are out, as are any signatures that aren't the last of
580 a series of uid sigs or revocations It breaks down like this:
581 coming out of mark_usable_uid_certs, if a sig is unflagged, it is
582 not even a candidate. If a sig has flag 9 or 10, that means it
583 was selected as a candidate and vetted. If a sig has flag 8 it
584 is a usable signature. If a sig has flag 11 it is a usable
585 revocation. If a sig has flag 12 it was issued by an unavailable
586 key. "Usable" here means the most recent valid
587 signature/revocation in a series from a particular signer.
589 Delete everything that isn't a usable uid sig (which might be
590 expired), a usable revocation, or a sig from an unavailable
593 for (node=uidnode->next;
594 node && node->pkt->pkttype==PKT_SIGNATURE;
599 keep = self_only? (node->pkt->pkt.signature->keyid[0] == keyid[0]
600 && node->pkt->pkt.signature->keyid[1] == keyid[1]) : 1;
602 /* Keep usable uid sigs ... */
603 if ((node->flag & (1<<8)) && keep)
606 /* ... and usable revocations... */
607 if ((node->flag & (1<<11)) && keep)
610 /* ... and sigs from unavailable keys. */
611 /* disabled for now since more people seem to want sigs from
612 unavailable keys removed altogether. */
614 if(node->flag & (1<<12))
618 /* Everything else we delete */
620 /* At this point, if 12 is set, the signing key was unavailable.
621 If 9 or 10 is set, it's superseded. Otherwise, it's
625 log_info ("removing signature from key %s on user ID \"%s\": %s\n",
626 keystr (node->pkt->pkt.signature->keyid),
627 uidnode->pkt->pkt.user_id->name,
628 node->flag&(1<<12)? "key unavailable":
629 node->flag&(1<<9)? "signature superseded"
630 /* */ :"invalid signature" );
632 delete_kbnode (node);
640 /* This is substantially easier than clean_sigs_from_uid since we just
641 have to establish if the uid has a valid self-sig, is not revoked,
642 and is not expired. Note that this does not take into account
643 whether the uid has a trust path to it - just whether the keyholder
644 themselves has certified the uid. Returns true if the uid was
645 compacted. To "compact" a user ID, we simply remove ALL signatures
646 except the self-sig that caused the user ID to be remove-worthy.
647 We don't actually remove the user ID packet itself since it might
648 be resurrected in a later merge. Note that this function requires
649 that the caller has already done a merge_keys_and_selfsig().
651 TODO: change the import code to allow importing a uid with only a
652 revocation if the uid already exists on the keyring. */
655 clean_uid_from_key (kbnode_t keyblock, kbnode_t uidnode, int noisy)
658 PKT_user_id *uid = uidnode->pkt->pkt.user_id;
661 log_assert (keyblock->pkt->pkttype==PKT_PUBLIC_KEY);
662 log_assert (uidnode->pkt->pkttype==PKT_USER_ID);
664 /* Skip valid user IDs, compacted user IDs, and non-self-signed user
665 IDs if --allow-non-selfsigned-uid is set. */
667 || uid->flags.compacted
668 || (!uid->is_expired && !uid->is_revoked && opt.allow_non_selfsigned_uid))
671 for (node=uidnode->next;
672 node && node->pkt->pkttype == PKT_SIGNATURE;
675 if (!node->pkt->pkt.signature->flags.chosen_selfsig)
677 delete_kbnode (node);
679 uidnode->pkt->pkt.user_id->flags.compacted = 1;
686 char *user = utf8_to_native (uid->name, uid->len, 0);
689 reason = _("revoked");
690 else if (uid->is_expired)
691 reason = _("expired");
693 reason = _("invalid");
695 log_info ("compacting user ID \"%s\" on key %s: %s\n",
696 user, keystr_from_pk (keyblock->pkt->pkt.public_key),
706 /* Needs to be called after a merge_keys_and_selfsig() */
708 clean_one_uid (kbnode_t keyblock, kbnode_t uidnode, int noisy, int self_only,
709 int *uids_cleaned, int *sigs_cleaned)
713 log_assert (keyblock->pkt->pkttype==PKT_PUBLIC_KEY);
714 log_assert (uidnode->pkt->pkttype==PKT_USER_ID);
717 uids_cleaned = &dummy;
720 sigs_cleaned = &dummy;
722 /* Do clean_uid_from_key first since if it fires off, we don't have
723 to bother with the other. */
724 *uids_cleaned += clean_uid_from_key (keyblock, uidnode, noisy);
725 if (!uidnode->pkt->pkt.user_id->flags.compacted)
726 *sigs_cleaned += clean_sigs_from_uid (keyblock, uidnode, noisy, self_only);
731 clean_key (kbnode_t keyblock, int noisy, int self_only,
732 int *uids_cleaned, int *sigs_cleaned)
736 merge_keys_and_selfsig (keyblock);
738 for (uidnode = keyblock->next;
739 uidnode && uidnode->pkt->pkttype != PKT_PUBLIC_SUBKEY;
740 uidnode = uidnode->next)
742 if (uidnode->pkt->pkttype == PKT_USER_ID)
743 clean_one_uid (keyblock, uidnode,noisy, self_only,
744 uids_cleaned, sigs_cleaned);