File: keyid.c

package info (click to toggle)
onak 0.5.0-1
  • links: PTS, VCS
  • area: main
  • in suites: buster, stretch
  • size: 1,788 kB
  • ctags: 819
  • sloc: ansic: 12,323; perl: 301; sh: 283; makefile: 179; sql: 21
file content (304 lines) | stat: -rw-r--r-- 7,226 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
/*
 * keyid.c - Routines to calculate key IDs.
 *
 * Copyright 2002,2011 Jonathan McDowell <noodles@earth.li>
 *
 * 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.
 *
 * 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, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include <string.h>
#include <sys/types.h>
#include <arpa/inet.h>

#include "config.h"
#include "keyid.h"
#include "keystructs.h"
#include "onak.h"
#include "parsekey.h"
#include "mem.h"
#include "merge.h"

#ifdef HAVE_NETTLE
#include <nettle/md5.h>
#include <nettle/ripemd160.h>
#include <nettle/sha.h>
#else
#include "md5.h"
#include "sha1.h"
#endif

uint64_t fingerprint2keyid(struct openpgp_fingerprint *fingerprint)
{
	uint64_t keyid;
	int i;

	for (keyid = 0, i = 12; i < 20; i++) {
		keyid <<= 8;
		keyid += fingerprint->fp[i];
	}

	return keyid;
}


/**
 *	get_keyid - Given a public key returns the keyid.
 *	@publickey: The key to calculate the id for.
 */
onak_status_t get_keyid(struct openpgp_publickey *publickey, uint64_t *keyid)
{
	return (get_packetid(publickey->publickey, keyid));
}

/**
 *	get_fingerprint - Given a public key returns the fingerprint.
 *	@publickey: The key to calculate the id for.
 *	@fingerprint: The fingerprint (must be at least 20 bytes of space).
 *	@len: The length of the returned fingerprint.
 *
 *	This function returns the fingerprint for a given public key. As Type 3
 *	fingerprints are 16 bytes and Type 4 are 20 the len field indicates
 *	which we've returned.
 */
onak_status_t get_fingerprint(struct openpgp_packet *packet,
	struct openpgp_fingerprint *fingerprint)
{
	struct sha1_ctx sha_ctx;
	struct md5_ctx md5_context;
	unsigned char c;
	size_t         modlen, explen;

	if (fingerprint == NULL)
		return ONAK_E_INVALID_PARAM;

	fingerprint->length = 0;

	switch (packet->data[0]) {
	case 2:
	case 3:
		md5_init(&md5_context);

		/*
		 * MD5 the modulus and exponent.
		 */
		modlen = ((packet->data[8] << 8) +
			 packet->data[9] + 7) >> 3;
		md5_update(&md5_context, modlen, &packet->data[10]);

		explen = ((packet->data[10+modlen] << 8) +
			 packet->data[11+modlen] + 7) >> 3;
		md5_update(&md5_context, explen, &packet->data[12 + modlen]);

		fingerprint->length = 16;
		md5_digest(&md5_context, fingerprint->length, fingerprint->fp);

		break;

	case 4:
		sha1_init(&sha_ctx);
		/*
		 * TODO: Can this be 0x99? Are all public key packets old
		 * format with 2 bytes of length data?
		 */
		c = 0x99;
		sha1_update(&sha_ctx, sizeof(c), &c);
		c = packet->length >> 8;
		sha1_update(&sha_ctx, sizeof(c), &c);
		c = packet->length & 0xFF;
		sha1_update(&sha_ctx, sizeof(c), &c);
		sha1_update(&sha_ctx, packet->length,
			packet->data);
		fingerprint->length = 20;
		sha1_digest(&sha_ctx, fingerprint->length, fingerprint->fp);

		break;
	default:
		return ONAK_E_UNKNOWN_VER;
	}

	return ONAK_E_OK;
}


/**
 *	get_packetid - Given a PGP packet returns the keyid.
 *	@packet: The packet to calculate the id for.
 */
onak_status_t get_packetid(struct openpgp_packet *packet, uint64_t *keyid)
{
	int		offset = 0;
	int		i = 0;
	struct openpgp_fingerprint fingerprint;
#ifdef NETTLE_WITH_RIPEMD160
	struct ripemd160_ctx ripemd160_context;
	uint8_t		data;
#endif

	if (packet == NULL || packet->data == NULL)
		return ONAK_E_INVALID_PARAM;

	switch (packet->data[0]) {
	case 2:
	case 3:
		/*
		 * Old versions of GnuPG would put Elgamal keys inside
		 * a V3 key structure, then generate the keyid using
		 * RIPED160.
		 */
#ifdef NETTLE_WITH_RIPEMD160
		if (packet->data[7] == 16) {
			ripemd160_init(&ripemd160_context);
			data = 0x99;
			ripemd160_update(&ripemd160_context, 1, &data);
			data = packet->length >> 8;
			ripemd160_update(&ripemd160_context, 1, &data);
			data = packet->length & 0xFF;
			ripemd160_update(&ripemd160_context, 1, &data);
			ripemd160_update(&ripemd160_context,
				packet->length,
				packet->data);

			ripemd160_digest(&ripemd160_context,
				RIPEMD160_DIGEST_SIZE,
				fingerprint.fp);
			fingerprint.length = RIPEMD160_DIGEST_SIZE;

			*keyid = fingerprint2keyid(&fingerprint);

			return ONAK_E_OK;
		}
#endif
		/*
		 * Check for an RSA key; if not return an error.
		 * 1 == RSA
		 * 2 == RSA Encrypt-Only
		 * 3 == RSA Sign-Only
		 */
		if (packet->data[7] < 1 || packet->data[7] > 3) {
			return ONAK_E_INVALID_PKT;
		}

		/*
		 * For a type 2 or 3 key the keyid is the last 64 bits of the
		 * public modulus n, which is stored as an MPI from offset 8
		 * onwards.
		 */
		offset = (packet->data[8] << 8) +
			packet->data[9];
		offset = ((offset + 7) / 8) + 2;

		for (*keyid = 0, i = 0; i < 8; i++) {
			*keyid <<= 8;
			*keyid += packet->data[offset++];
		}
		break;
	case 4:
		get_fingerprint(packet, &fingerprint);

		*keyid = fingerprint2keyid(&fingerprint);

		break;
	default:
		return ONAK_E_UNKNOWN_VER;
	}

	return ONAK_E_OK;
}

static struct openpgp_packet_list *sortpackets(struct openpgp_packet_list
							*packets)
{
	struct openpgp_packet_list *sorted, **cur, *next;

	sorted = NULL;
	while (packets != NULL) {
		cur = &sorted;
		while (*cur != NULL && compare_packets((*cur)->packet,
				packets->packet) < 0) {
			cur = &((*cur)->next);
		}
		next = *cur;
		*cur = packets;
		packets = packets->next;
		(*cur)->next = next;
	}

	return sorted;
}

onak_status_t get_skshash(struct openpgp_publickey *key, struct skshash *hash)
{
	struct openpgp_packet_list *packets = NULL, *list_end = NULL;
	struct openpgp_packet_list *curpacket;
	struct md5_ctx md5_context;
	struct openpgp_publickey *next;
	uint32_t tmp;

	/*
	 * We only want a single key, so clear any link to the next
	 * one for the period during the flatten.
	 */
	next = key->next;
	key->next = NULL;
	flatten_publickey(key, &packets, &list_end);
	key->next = next;
	packets = sortpackets(packets);

	md5_init(&md5_context);

	for (curpacket = packets; curpacket != NULL;
			curpacket = curpacket->next) {
		tmp = htonl(curpacket->packet->tag);
		md5_update(&md5_context, sizeof(tmp), (void *) &tmp);
		tmp = htonl(curpacket->packet->length);
		md5_update(&md5_context, sizeof(tmp), (void *) &tmp);
		md5_update(&md5_context,
				curpacket->packet->length,
				curpacket->packet->data);
	}

	md5_digest(&md5_context, 16, (uint8_t *) &hash->hash);
	free_packet_list(packets);

	return ONAK_E_OK;
}

uint8_t hexdigit(char c)
{
	if (c >= '0' && c <= '9')
		return c - '0';
	else if (c >= 'a' && c <= 'f')
		return c - 'a' + 10;
	else if (c >= 'A' && c <= 'F')
		return c - 'A' + 10;
	else
		return 0;
}

int parse_skshash(char *search, struct skshash *hash)
{
	int i, len;

	len = strlen(search);
	if (len > 32) {
		return 0;
	}

	for (i = 0; i < len; i += 2) {
		hash->hash[i >> 1] = (hexdigit(search[i]) << 4) +
				hexdigit(search[i + 1]);
	}

	return 1;
}