/*
* cleankey.c - Routines to look for common key problems and clean them up.
*
- * Jonathan McDowell <noodles@earth.li>
+ * Copyright 2004,2012 Jonathan McDowell <noodles@earth.li>
*
- * Copyright 2004 Project Purple
+ * This program 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; version 2 of the License.
*
- * $Id: cleankey.c,v 1.1 2004/05/31 14:16:49 noodles Exp $
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <https://www.gnu.org/licenses/>.
*/
-#include <assert.h>
#include <stdbool.h>
-#include <stdio.h>
#include <stdlib.h>
+#include "build-config.h"
#include "cleankey.h"
+#include "decodekey.h"
+#include "keyid.h"
#include "keystructs.h"
+#include "log.h"
#include "mem.h"
#include "merge.h"
-#include "log.h"
+#include "openpgp.h"
+#include "sigcheck.h"
/**
* dedupuids - Merge duplicate uids on a key.
struct openpgp_signedpacket_list *tmp = NULL;
int merged = 0;
- assert(key != NULL);
+ log_assert(key != NULL);
curuid = key->uids;
while (curuid != NULL) {
dup = find_signed_packet(curuid->next, curuid->packet);
while (tmp != NULL && tmp->next != dup) {
tmp = tmp->next;
}
- assert(tmp != NULL);
+ log_assert(tmp != NULL);
tmp->next = dup->next;
dup->next = NULL;
free_signedpacket_list(dup);
return merged;
}
+/**
+ * dedupsubkeys - Merge duplicate subkeys on a key.
+ * @key: The key to de-dup subkeys on.
+ *
+ * This function attempts to merge duplicate subkeys on a key. It returns
+ * 0 if the key is unchanged, otherwise the number of dups merged.
+ */
+int dedupsubkeys(struct openpgp_publickey *key)
+{
+ struct openpgp_signedpacket_list *cursubkey = NULL;
+ struct openpgp_signedpacket_list *dup = NULL;
+ struct openpgp_signedpacket_list *tmp = NULL;
+ int merged = 0;
+ uint64_t subkeyid;
+
+ log_assert(key != NULL);
+ cursubkey = key->subkeys;
+ while (cursubkey != NULL) {
+ dup = find_signed_packet(cursubkey->next, cursubkey->packet);
+ while (dup != NULL) {
+ get_packetid(cursubkey->packet, &subkeyid);
+ logthing(LOGTHING_INFO,
+ "Found duplicate subkey: 0x%016" PRIX64,
+ subkeyid);
+ merged++;
+ merge_packet_sigs(cursubkey, dup);
+ /*
+ * Remove the duplicate uid.
+ */
+ tmp = cursubkey;
+ while (tmp != NULL && tmp->next != dup) {
+ tmp = tmp->next;
+ }
+ log_assert(tmp != NULL);
+ tmp->next = dup->next;
+ dup->next = NULL;
+ free_signedpacket_list(dup);
+
+ dup = find_signed_packet(cursubkey->next,
+ cursubkey->packet);
+ }
+ cursubkey = cursubkey->next;
+ }
+
+ return merged;
+}
+
+/**
+ * check_sighashes - Check that sig hashes are correct.
+ * @key - the check to check the sig hashes of.
+ *
+ * Given an OpenPGP key confirm that all of the sigs on it have the
+ * appropriate 2 octet hash beginning, as stored as part of the sig.
+ * This is a simple way to remove junk sigs and, for example, catches
+ * subkey sig corruption as produced by old pksd implementations.
+ * Any sig that has an incorrect hash is removed from the key. If the
+ * hash cannot be checked (eg we don't support that hash type) we err
+ * on the side of caution and keep it.
+ */
+int clean_sighashes(struct onak_dbctx *dbctx,
+ struct openpgp_publickey *key,
+ struct openpgp_packet *sigdata,
+ struct openpgp_packet_list **sigs,
+ bool fullverify,
+ bool *selfsig, bool *othersig)
+{
+ struct openpgp_packet_list *tmpsig;
+ struct openpgp_publickey *sigkeys = NULL, *curkey;
+ onak_status_t ret;
+ uint8_t hashtype;
+ uint8_t hash[64];
+ uint8_t *sighash;
+ int removed = 0;
+ uint64_t keyid, sigid;
+ bool remove;
+
+ get_keyid(key, &keyid);
+ if (othersig != NULL) {
+ *othersig = false;
+ }
+ if (selfsig != NULL) {
+ *selfsig = false;
+ }
+ while (*sigs != NULL) {
+ remove = false;
+ ret = calculate_packet_sighash(key, sigdata, (*sigs)->packet,
+ &hashtype, hash, &sighash);
+
+ if (ret == ONAK_E_UNSUPPORTED_FEATURE) {
+ get_keyid(key, &keyid);
+ logthing(LOGTHING_ERROR,
+ "Unsupported signature hash type %d on 0x%016"
+ PRIX64,
+ hashtype,
+ keyid);
+ if (fullverify) {
+ remove = true;
+ }
+ } else if (ret != ONAK_E_OK || (!fullverify &&
+ !(hash[0] == sighash[0] &&
+ hash[1] == sighash[1]))) {
+ remove = true;
+ }
+
+#if HAVE_CRYPTO
+ if (fullverify && !remove) {
+ sig_info((*sigs)->packet, &sigid, NULL);
+
+ /* Start by assuming it's a bad sig */
+
+ remove = true;
+ if (sigid == keyid) {
+ ret = onak_check_hash_sig(key, (*sigs)->packet,
+ hash, hashtype);
+
+ /* We have a valid self signature */
+ if (ret == ONAK_E_OK) {
+ remove = false;
+ if (selfsig != NULL) {
+ *selfsig = true;
+ }
+ }
+ }
+
+ if (remove) {
+ dbctx->fetch_key_id(dbctx, sigid,
+ &sigkeys, false);
+ }
+
+ /*
+ * A 64 bit collision is probably a sign of something
+ * sneaky happening, but if the signature verifies we
+ * should keep it.
+ */
+ for (curkey = sigkeys; curkey != NULL;
+ curkey = curkey->next) {
+
+ ret = onak_check_hash_sig(curkey,
+ (*sigs)->packet,
+ hash, hashtype);
+
+ /* Got a valid signature */
+ if (ret == ONAK_E_OK) {
+ remove = false;
+ if (othersig != NULL) {
+ *othersig = true;
+ }
+ break;
+ }
+ }
+
+ free_publickey(sigkeys);
+ sigkeys = NULL;
+ }
+#endif
+
+ if (remove) {
+ tmpsig = *sigs;
+ *sigs = (*sigs)->next;
+ tmpsig->next = NULL;
+ free_packet_list(tmpsig);
+ removed++;
+ } else {
+ sigs = &(*sigs)->next;
+ }
+ }
+
+ return removed;
+}
+
+int clean_list_sighashes(struct onak_dbctx *dbctx,
+ struct openpgp_publickey *key,
+ struct openpgp_signedpacket_list **siglist,
+ bool fullverify, bool needother)
+{
+ struct openpgp_signedpacket_list *tmp = NULL;
+ bool selfsig, othersig;
+ int removed = 0;
+
+ while (siglist != NULL && *siglist != NULL) {
+ selfsig = othersig = false;
+
+ removed += clean_sighashes(dbctx, key, (*siglist)->packet,
+ &(*siglist)->sigs, fullverify, &selfsig, &othersig);
+
+ if (fullverify && (!selfsig || (needother && !othersig))) {
+ /* Remove the UID/subkey if there's no selfsig */
+ tmp = *siglist;
+ *siglist = (*siglist)->next;
+ tmp->next = NULL;
+ free_signedpacket_list(tmp);
+ } else {
+ siglist = &(*siglist)->next;
+ }
+ }
+
+ return removed;
+}
+
+int clean_key_signatures(struct onak_dbctx *dbctx,
+ struct openpgp_publickey *key, bool fullverify, bool needother)
+{
+ int removed;
+
+ removed = clean_sighashes(dbctx, key, NULL, &key->sigs, fullverify,
+ NULL, NULL);
+ removed += clean_list_sighashes(dbctx, key, &key->uids, fullverify,
+ needother);
+ removed += clean_list_sighashes(dbctx, key, &key->subkeys, fullverify,
+ false);
+
+ return removed;
+}
+
+#define UAT_LIMIT 0xFFFF
+#define UID_LIMIT 1024
+#define PACKET_LIMIT 8383 /* Fits in 2 byte packet length */
+int clean_large_packets(struct openpgp_publickey *key)
+{
+ struct openpgp_signedpacket_list **curuid = NULL;
+ struct openpgp_signedpacket_list *tmp = NULL;
+ bool drop;
+ int dropped = 0;
+
+ log_assert(key != NULL);
+ curuid = &key->uids;
+ while (*curuid != NULL) {
+ drop = false;
+ switch ((*curuid)->packet->tag) {
+ case OPENPGP_PACKET_UID:
+ if ((*curuid)->packet->length > UID_LIMIT)
+ drop = true;
+ break;
+ case OPENPGP_PACKET_UAT:
+ if ((*curuid)->packet->length > UAT_LIMIT)
+ drop = true;
+ break;
+ default:
+ if ((*curuid)->packet->length > PACKET_LIMIT)
+ drop = true;
+ break;
+ }
+
+ if (drop) {
+ logthing(LOGTHING_INFO,
+ "Dropping large (%d) packet, type %d",
+ (*curuid)->packet->length,
+ (*curuid)->packet->tag);
+ /* Remove the entire large signed packet list */
+ tmp = *curuid;
+ *curuid = (*curuid)->next;
+ tmp->next = NULL;
+ free_signedpacket_list(tmp);
+ dropped++;
+ } else {
+ curuid = &(*curuid)->next;
+ }
+ }
+
+ return dropped;
+}
+
/**
* cleankeys - Apply all available cleaning options on a list of keys.
- * @keys: The list of keys to clean.
+ * @policies: The cleaning policies to apply.
*
- * Applies all the cleaning options we can (eg duplicate key ids) to a
- * list of keys. Returns 0 if no changes were made, otherwise the number
- * of keys cleaned.
+ * Applies the requested cleaning policies to a list of keys. These are
+ * specified from the ONAK_CLEAN_* set of flags, or ONAK_CLEAN_ALL to
+ * apply all available cleaning options. Returns 0 if no changes were
+ * made, otherwise the number of keys cleaned. Note that some options
+ * may result in keys being removed entirely from the list.
*/
-int cleankeys(struct openpgp_publickey *keys)
+int cleankeys(struct onak_dbctx *dbctx, struct openpgp_publickey **keys,
+ uint64_t policies)
{
- int changed = 0;
+ struct openpgp_publickey **curkey, *tmp;
+ int changed = 0, count = 0;
+
+ if (keys == NULL)
+ return 0;
- while (keys != NULL) {
- if (dedupuids(keys) > 0) {
+ curkey = keys;
+ while (*curkey != NULL) {
+ if (policies & ONAK_CLEAN_DROP_V3_KEYS) {
+ if ((*curkey)->publickey->data[0] < 4) {
+ /* Remove the key from the list if it's < v4 */
+ tmp = *curkey;
+ *curkey = tmp->next;
+ tmp->next = NULL;
+ free_publickey(tmp);
+ changed++;
+ continue;
+ }
+ }
+ if (policies & ONAK_CLEAN_LARGE_PACKETS) {
+ count += clean_large_packets(*curkey);
+ }
+ count += dedupuids(*curkey);
+ count += dedupsubkeys(*curkey);
+ if (policies & (ONAK_CLEAN_CHECK_SIGHASH |
+ ONAK_CLEAN_VERIFY_SIGNATURES)) {
+ count += clean_key_signatures(dbctx, *curkey,
+ policies & ONAK_CLEAN_VERIFY_SIGNATURES,
+ policies & ONAK_CLEAN_NEED_OTHER_SIG);
+ }
+ if (count > 0) {
changed++;
}
- keys = keys->next;
+ if ((*curkey)->uids == NULL) {
+ /* No valid UIDS so remove the key from the list */
+ tmp = *curkey;
+ *curkey = tmp->next;
+ tmp->next = NULL;
+ free_publickey(tmp);
+ } else {
+ curkey = &(*curkey)->next;
+ }
}
return changed;
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