2 * keyid.c - Routines to calculate key IDs.
4 * Copyright 2002,2011 Jonathan McDowell <noodles@earth.li>
6 * This program is free software: you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; version 2 of the License.
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * You should have received a copy of the GNU General Public License along with
16 * this program. If not, see <https://www.gnu.org/licenses/>.
20 #include <sys/types.h>
21 #include <arpa/inet.h>
25 #include "keystructs.h"
32 #include <nettle/md5.h>
33 #include <nettle/ripemd160.h>
34 #include <nettle/sha.h>
40 uint64_t fingerprint2keyid(struct openpgp_fingerprint *fingerprint)
45 for (keyid = 0, i = 12; i < 20; i++) {
47 keyid += fingerprint->fp[i];
55 * get_keyid - Given a public key returns the keyid.
56 * @publickey: The key to calculate the id for.
58 onak_status_t get_keyid(struct openpgp_publickey *publickey, uint64_t *keyid)
60 return (get_packetid(publickey->publickey, keyid));
64 * get_fingerprint - Given a public key returns the fingerprint.
65 * @publickey: The key to calculate the id for.
66 * @fingerprint: The fingerprint (must be at least 20 bytes of space).
67 * @len: The length of the returned fingerprint.
69 * This function returns the fingerprint for a given public key. As Type 3
70 * fingerprints are 16 bytes and Type 4 are 20 the len field indicates
71 * which we've returned.
73 onak_status_t get_fingerprint(struct openpgp_packet *packet,
74 struct openpgp_fingerprint *fingerprint)
76 struct sha1_ctx sha_ctx;
77 struct md5_ctx md5_context;
79 size_t modlen, explen;
81 if (fingerprint == NULL)
82 return ONAK_E_INVALID_PARAM;
84 fingerprint->length = 0;
86 switch (packet->data[0]) {
89 md5_init(&md5_context);
92 * MD5 the modulus and exponent.
94 modlen = ((packet->data[8] << 8) +
95 packet->data[9] + 7) >> 3;
96 md5_update(&md5_context, modlen, &packet->data[10]);
98 explen = ((packet->data[10+modlen] << 8) +
99 packet->data[11+modlen] + 7) >> 3;
100 md5_update(&md5_context, explen, &packet->data[12 + modlen]);
102 fingerprint->length = 16;
103 md5_digest(&md5_context, fingerprint->length, fingerprint->fp);
110 * TODO: Can this be 0x99? Are all public key packets old
111 * format with 2 bytes of length data?
114 sha1_update(&sha_ctx, sizeof(c), &c);
115 c = packet->length >> 8;
116 sha1_update(&sha_ctx, sizeof(c), &c);
117 c = packet->length & 0xFF;
118 sha1_update(&sha_ctx, sizeof(c), &c);
119 sha1_update(&sha_ctx, packet->length,
121 fingerprint->length = 20;
122 sha1_digest(&sha_ctx, fingerprint->length, fingerprint->fp);
126 return ONAK_E_UNKNOWN_VER;
134 * get_packetid - Given a PGP packet returns the keyid.
135 * @packet: The packet to calculate the id for.
137 onak_status_t get_packetid(struct openpgp_packet *packet, uint64_t *keyid)
141 struct openpgp_fingerprint fingerprint;
142 #ifdef NETTLE_WITH_RIPEMD160
143 struct ripemd160_ctx ripemd160_context;
147 if (packet == NULL || packet->data == NULL)
148 return ONAK_E_INVALID_PARAM;
150 switch (packet->data[0]) {
154 * Old versions of GnuPG would put Elgamal keys inside
155 * a V3 key structure, then generate the keyid using
158 #ifdef NETTLE_WITH_RIPEMD160
159 if (packet->data[7] == 16) {
160 ripemd160_init(&ripemd160_context);
162 ripemd160_update(&ripemd160_context, 1, &data);
163 data = packet->length >> 8;
164 ripemd160_update(&ripemd160_context, 1, &data);
165 data = packet->length & 0xFF;
166 ripemd160_update(&ripemd160_context, 1, &data);
167 ripemd160_update(&ripemd160_context,
171 ripemd160_digest(&ripemd160_context,
172 RIPEMD160_DIGEST_SIZE,
174 fingerprint.length = RIPEMD160_DIGEST_SIZE;
176 *keyid = fingerprint2keyid(&fingerprint);
182 * Check for an RSA key; if not return an error.
184 * 2 == RSA Encrypt-Only
187 if (packet->data[7] < 1 || packet->data[7] > 3) {
188 return ONAK_E_INVALID_PKT;
192 * For a type 2 or 3 key the keyid is the last 64 bits of the
193 * public modulus n, which is stored as an MPI from offset 8
196 offset = (packet->data[8] << 8) +
198 offset = ((offset + 7) / 8) + 2;
200 for (*keyid = 0, i = 0; i < 8; i++) {
202 *keyid += packet->data[offset++];
206 get_fingerprint(packet, &fingerprint);
208 *keyid = fingerprint2keyid(&fingerprint);
212 return ONAK_E_UNKNOWN_VER;
218 static struct openpgp_packet_list *sortpackets(struct openpgp_packet_list
221 struct openpgp_packet_list *sorted, **cur, *next;
224 while (packets != NULL) {
226 while (*cur != NULL && compare_packets((*cur)->packet,
227 packets->packet) < 0) {
228 cur = &((*cur)->next);
232 packets = packets->next;
239 onak_status_t get_skshash(struct openpgp_publickey *key, struct skshash *hash)
241 struct openpgp_packet_list *packets = NULL, *list_end = NULL;
242 struct openpgp_packet_list *curpacket;
243 struct md5_ctx md5_context;
244 struct openpgp_publickey *next;
248 * We only want a single key, so clear any link to the next
249 * one for the period during the flatten.
253 flatten_publickey(key, &packets, &list_end);
255 packets = sortpackets(packets);
257 md5_init(&md5_context);
259 for (curpacket = packets; curpacket != NULL;
260 curpacket = curpacket->next) {
261 tmp = htonl(curpacket->packet->tag);
262 md5_update(&md5_context, sizeof(tmp), (void *) &tmp);
263 tmp = htonl(curpacket->packet->length);
264 md5_update(&md5_context, sizeof(tmp), (void *) &tmp);
265 md5_update(&md5_context,
266 curpacket->packet->length,
267 curpacket->packet->data);
270 md5_digest(&md5_context, 16, (uint8_t *) &hash->hash);
271 free_packet_list(packets);
276 uint8_t hexdigit(char c)
278 if (c >= '0' && c <= '9')
280 else if (c >= 'a' && c <= 'f')
282 else if (c >= 'A' && c <= 'F')
288 int parse_skshash(char *search, struct skshash *hash)
292 len = strlen(search);
297 for (i = 0; i < len; i += 2) {
298 hash->hash[i >> 1] = (hexdigit(search[i]) << 4) +
299 hexdigit(search[i + 1]);