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, write to the Free Software Foundation, Inc., 51
17 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 #include <sys/types.h>
22 #include <arpa/inet.h>
26 #include "keystructs.h"
33 #include <nettle/md5.h>
34 #include <nettle/ripemd160.h>
35 #include <nettle/sha.h>
41 uint64_t fingerprint2keyid(struct openpgp_fingerprint *fingerprint)
47 for (keyid = 0, i = 12; i < 20; i++) {
49 keyid += fingerprint->fp[i];
57 * get_keyid - Given a public key returns the keyid.
58 * @publickey: The key to calculate the id for.
60 onak_status_t get_keyid(struct openpgp_publickey *publickey, uint64_t *keyid)
62 return (get_packetid(publickey->publickey, keyid));
66 * get_fingerprint - Given a public key returns the fingerprint.
67 * @publickey: The key to calculate the id for.
68 * @fingerprint: The fingerprint (must be at least 20 bytes of space).
69 * @len: The length of the returned fingerprint.
71 * This function returns the fingerprint for a given public key. As Type 3
72 * fingerprints are 16 bytes and Type 4 are 20 the len field indicates
73 * which we've returned.
75 onak_status_t get_fingerprint(struct openpgp_packet *packet,
76 struct openpgp_fingerprint *fingerprint)
78 struct sha1_ctx sha_ctx;
79 struct md5_ctx md5_context;
81 size_t modlen, explen;
83 if (fingerprint == NULL)
84 return ONAK_E_INVALID_PARAM;
86 fingerprint->length = 0;
88 switch (packet->data[0]) {
91 md5_init(&md5_context);
94 * MD5 the modulus and exponent.
96 modlen = ((packet->data[8] << 8) +
97 packet->data[9] + 7) >> 3;
98 md5_update(&md5_context, modlen, &packet->data[10]);
100 explen = ((packet->data[10+modlen] << 8) +
101 packet->data[11+modlen] + 7) >> 3;
102 md5_update(&md5_context, explen, &packet->data[12 + modlen]);
104 fingerprint->length = 16;
105 md5_digest(&md5_context, fingerprint->length, fingerprint->fp);
112 * TODO: Can this be 0x99? Are all public key packets old
113 * format with 2 bytes of length data?
116 sha1_update(&sha_ctx, sizeof(c), &c);
117 c = packet->length >> 8;
118 sha1_update(&sha_ctx, sizeof(c), &c);
119 c = packet->length & 0xFF;
120 sha1_update(&sha_ctx, sizeof(c), &c);
121 sha1_update(&sha_ctx, packet->length,
123 fingerprint->length = 20;
124 sha1_digest(&sha_ctx, fingerprint->length, fingerprint->fp);
128 return ONAK_E_UNKNOWN_VER;
136 * get_packetid - Given a PGP packet returns the keyid.
137 * @packet: The packet to calculate the id for.
139 onak_status_t get_packetid(struct openpgp_packet *packet, uint64_t *keyid)
143 struct openpgp_fingerprint fingerprint;
144 #ifdef NETTLE_WITH_RIPEMD160
145 struct ripemd160_ctx ripemd160_context;
150 return ONAK_E_INVALID_PARAM;
152 switch (packet->data[0]) {
156 * Old versions of GnuPG would put Elgamal keys inside
157 * a V3 key structure, then generate the keyid using
160 #ifdef NETTLE_WITH_RIPEMD160
161 if (packet->data[7] == 16) {
162 ripemd160_init(&ripemd160_context);
164 ripemd160_update(&ripemd160_context, 1, &data);
165 data = packet->length >> 8;
166 ripemd160_update(&ripemd160_context, 1, &data);
167 data = packet->length & 0xFF;
168 ripemd160_update(&ripemd160_context, 1, &data);
169 ripemd160_update(&ripemd160_context,
173 ripemd160_digest(&ripemd160_context,
174 RIPEMD160_DIGEST_SIZE,
176 fingerprint.length = RIPEMD160_DIGEST_SIZE;
178 *keyid = fingerprint2keyid(&fingerprint);
184 * Check for an RSA key; if not return an error.
186 * 2 == RSA Encrypt-Only
189 if (packet->data[7] < 1 || packet->data[7] > 3) {
190 return ONAK_E_INVALID_PKT;
194 * For a type 2 or 3 key the keyid is the last 64 bits of the
195 * public modulus n, which is stored as an MPI from offset 8
198 offset = (packet->data[8] << 8) +
200 offset = ((offset + 7) / 8) + 2;
202 for (*keyid = 0, i = 0; i < 8; i++) {
204 *keyid += packet->data[offset++];
208 get_fingerprint(packet, &fingerprint);
210 *keyid = fingerprint2keyid(&fingerprint);
214 return ONAK_E_UNKNOWN_VER;
220 static struct openpgp_packet_list *sortpackets(struct openpgp_packet_list
223 struct openpgp_packet_list *sorted, **cur, *next;
226 while (packets != NULL) {
228 while (*cur != NULL && compare_packets((*cur)->packet,
229 packets->packet) < 0) {
230 cur = &((*cur)->next);
234 packets = packets->next;
241 onak_status_t get_skshash(struct openpgp_publickey *key, struct skshash *hash)
243 struct openpgp_packet_list *packets = NULL, *list_end = NULL;
244 struct openpgp_packet_list *curpacket;
245 struct md5_ctx md5_context;
246 struct openpgp_publickey *next;
250 * We only want a single key, so clear any link to the next
251 * one for the period during the flatten.
255 flatten_publickey(key, &packets, &list_end);
257 packets = sortpackets(packets);
259 md5_init(&md5_context);
261 for (curpacket = packets; curpacket != NULL;
262 curpacket = curpacket->next) {
263 tmp = htonl(curpacket->packet->tag);
264 md5_update(&md5_context, sizeof(tmp), (void *) &tmp);
265 tmp = htonl(curpacket->packet->length);
266 md5_update(&md5_context, sizeof(tmp), (void *) &tmp);
267 md5_update(&md5_context,
268 curpacket->packet->length,
269 curpacket->packet->data);
272 md5_digest(&md5_context, 16, (uint8_t *) &hash->hash);
273 free_packet_list(packets);
278 uint8_t hexdigit(char c)
280 if (c >= '0' && c <= '9')
282 else if (c >= 'a' && c <= 'f')
284 else if (c >= 'A' && c <= 'F')
290 int parse_skshash(char *search, struct skshash *hash)
294 len = strlen(search);
299 for (i = 0; i < len; i += 2) {
300 hash->hash[i >> 1] = (hexdigit(search[i]) << 4) +
301 hexdigit(search[i + 1]);