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)
46 for (keyid = 0, i = 12; i < 20; i++) {
48 keyid += fingerprint->fp[i];
56 * get_keyid - Given a public key returns the keyid.
57 * @publickey: The key to calculate the id for.
59 onak_status_t get_keyid(struct openpgp_publickey *publickey, uint64_t *keyid)
61 return (get_packetid(publickey->publickey, keyid));
65 * get_fingerprint - Given a public key returns the fingerprint.
66 * @publickey: The key to calculate the id for.
67 * @fingerprint: The fingerprint (must be at least 20 bytes of space).
68 * @len: The length of the returned fingerprint.
70 * This function returns the fingerprint for a given public key. As Type 3
71 * fingerprints are 16 bytes and Type 4 are 20 the len field indicates
72 * which we've returned.
74 onak_status_t get_fingerprint(struct openpgp_packet *packet,
75 struct openpgp_fingerprint *fingerprint)
77 struct sha1_ctx sha_ctx;
78 struct md5_ctx md5_context;
80 size_t modlen, explen;
82 if (fingerprint == NULL)
83 return ONAK_E_INVALID_PARAM;
85 fingerprint->length = 0;
87 switch (packet->data[0]) {
90 md5_init(&md5_context);
93 * MD5 the modulus and exponent.
95 modlen = ((packet->data[8] << 8) +
96 packet->data[9] + 7) >> 3;
97 md5_update(&md5_context, modlen, &packet->data[10]);
99 explen = ((packet->data[10+modlen] << 8) +
100 packet->data[11+modlen] + 7) >> 3;
101 md5_update(&md5_context, explen, &packet->data[12 + modlen]);
103 fingerprint->length = 16;
104 md5_digest(&md5_context, fingerprint->length, fingerprint->fp);
111 * TODO: Can this be 0x99? Are all public key packets old
112 * format with 2 bytes of length data?
115 sha1_update(&sha_ctx, sizeof(c), &c);
116 c = packet->length >> 8;
117 sha1_update(&sha_ctx, sizeof(c), &c);
118 c = packet->length & 0xFF;
119 sha1_update(&sha_ctx, sizeof(c), &c);
120 sha1_update(&sha_ctx, packet->length,
122 fingerprint->length = 20;
123 sha1_digest(&sha_ctx, fingerprint->length, fingerprint->fp);
127 return ONAK_E_UNKNOWN_VER;
135 * get_packetid - Given a PGP packet returns the keyid.
136 * @packet: The packet to calculate the id for.
138 onak_status_t get_packetid(struct openpgp_packet *packet, uint64_t *keyid)
142 struct openpgp_fingerprint fingerprint;
143 #ifdef NETTLE_WITH_RIPEMD160
144 struct ripemd160_ctx ripemd160_context;
149 return ONAK_E_INVALID_PARAM;
151 switch (packet->data[0]) {
155 * Old versions of GnuPG would put Elgamal keys inside
156 * a V3 key structure, then generate the keyid using
159 #ifdef NETTLE_WITH_RIPEMD160
160 if (packet->data[7] == 16) {
161 ripemd160_init(&ripemd160_context);
163 ripemd160_update(&ripemd160_context, 1, &data);
164 data = packet->length >> 8;
165 ripemd160_update(&ripemd160_context, 1, &data);
166 data = packet->length & 0xFF;
167 ripemd160_update(&ripemd160_context, 1, &data);
168 ripemd160_update(&ripemd160_context,
172 ripemd160_digest(&ripemd160_context,
173 RIPEMD160_DIGEST_SIZE,
175 fingerprint.length = RIPEMD160_DIGEST_SIZE;
177 *keyid = fingerprint2keyid(&fingerprint);
183 * Check for an RSA key; if not return an error.
185 * 2 == RSA Encrypt-Only
188 if (packet->data[7] < 1 || packet->data[7] > 3) {
189 return ONAK_E_INVALID_PKT;
193 * For a type 2 or 3 key the keyid is the last 64 bits of the
194 * public modulus n, which is stored as an MPI from offset 8
197 offset = (packet->data[8] << 8) +
199 offset = ((offset + 7) / 8) + 2;
201 for (*keyid = 0, i = 0; i < 8; i++) {
203 *keyid += packet->data[offset++];
207 get_fingerprint(packet, &fingerprint);
209 *keyid = fingerprint2keyid(&fingerprint);
213 return ONAK_E_UNKNOWN_VER;
219 static struct openpgp_packet_list *sortpackets(struct openpgp_packet_list
222 struct openpgp_packet_list *sorted, **cur, *next;
225 while (packets != NULL) {
227 while (*cur != NULL && compare_packets((*cur)->packet,
228 packets->packet) < 0) {
229 cur = &((*cur)->next);
233 packets = packets->next;
240 onak_status_t get_skshash(struct openpgp_publickey *key, struct skshash *hash)
242 struct openpgp_packet_list *packets = NULL, *list_end = NULL;
243 struct openpgp_packet_list *curpacket;
244 struct md5_ctx md5_context;
245 struct openpgp_publickey *next;
249 * We only want a single key, so clear any link to the next
250 * one for the period during the flatten.
254 flatten_publickey(key, &packets, &list_end);
256 packets = sortpackets(packets);
258 md5_init(&md5_context);
260 for (curpacket = packets; curpacket != NULL;
261 curpacket = curpacket->next) {
262 tmp = htonl(curpacket->packet->tag);
263 md5_update(&md5_context, sizeof(tmp), (void *) &tmp);
264 tmp = htonl(curpacket->packet->length);
265 md5_update(&md5_context, sizeof(tmp), (void *) &tmp);
266 md5_update(&md5_context,
267 curpacket->packet->length,
268 curpacket->packet->data);
271 md5_digest(&md5_context, 16, (uint8_t *) &hash->hash);
272 free_packet_list(packets);
277 uint8_t hexdigit(char c)
279 if (c >= '0' && c <= '9')
281 else if (c >= 'a' && c <= 'f')
283 else if (c >= 'A' && c <= 'F')
289 int parse_skshash(char *search, struct skshash *hash)
293 len = strlen(search);
298 for (i = 0; i < len; i += 2) {
299 hash->hash[i >> 1] = (hexdigit(search[i]) << 4) +
300 hexdigit(search[i + 1]);