2 * Copyright (c) 2000 Markus Friedl. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * 3. All advertising materials mentioning features or use of this software
13 * must display the following acknowledgement:
14 * This product includes software developed by Markus Friedl.
15 * 4. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 # include <openssl/bn.h>
43 # include <openssl/dh.h>
44 # include <openssl/crypto.h>
45 # include <openssl/bio.h>
46 # include <openssl/bn.h>
47 # include <openssl/dh.h>
48 # include <openssl/pem.h>
49 #endif /* HAVE_OPENSSL */
53 # include <ssl/crypto.h>
64 kex_init(char *myproposal[PROPOSAL_MAX])
67 unsigned char cookie[16];
70 Buffer *ki = xmalloc(sizeof(*ki));
71 for (i = 0; i < 16; i++) {
74 cookie[i] = rand & 0xff;
78 buffer_append(ki, (char *)cookie, sizeof cookie);
79 for (i = 0; i < PROPOSAL_MAX; i++)
80 buffer_put_cstring(ki, myproposal[i]);
81 buffer_append(ki, &c, 1); /* boolean first_kex_packet_follows */
82 buffer_put_int(ki, 0); /* uint32 0 (reserved for future extension) */
86 /* diffie-hellman-group1-sha1 */
92 "FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1"
93 "29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD"
94 "EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245"
95 "E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED"
96 "EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE65381"
97 "FFFFFFFF" "FFFFFFFF";
103 ret = BN_hex2bn(&dh->p,group1);
109 BN_set_word(dh->g,2);
112 if (DH_generate_key(dh) == 0)
113 fatal("DH_generate_key");
119 bignum_print(BIGNUM *b)
121 BN_print_fp(stderr,b);
125 dump_digest(unsigned char *digest, int len)
128 for (i = 0; i< len; i++){
129 fprintf(stderr, "%02x", digest[i]);
131 fprintf(stderr, " ");
133 fprintf(stderr, "\n");
138 char *client_version_string,
139 char *server_version_string,
140 char *ckexinit, int ckexinitlen,
141 char *skexinit, int skexinitlen,
142 char *serverhostkeyblob, int sbloblen,
143 BIGNUM *client_dh_pub,
144 BIGNUM *server_dh_pub,
145 BIGNUM *shared_secret)
148 static unsigned char digest[EVP_MAX_MD_SIZE];
149 EVP_MD *evp_md = EVP_sha1();
153 buffer_put_string(&b, client_version_string, strlen(client_version_string));
154 buffer_put_string(&b, server_version_string, strlen(server_version_string));
156 /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
157 buffer_put_int(&b, ckexinitlen+1);
158 buffer_put_char(&b, SSH2_MSG_KEXINIT);
159 buffer_append(&b, ckexinit, ckexinitlen);
160 buffer_put_int(&b, skexinitlen+1);
161 buffer_put_char(&b, SSH2_MSG_KEXINIT);
162 buffer_append(&b, skexinit, skexinitlen);
164 buffer_put_string(&b, serverhostkeyblob, sbloblen);
165 buffer_put_bignum2(&b, client_dh_pub);
166 buffer_put_bignum2(&b, server_dh_pub);
167 buffer_put_bignum2(&b, shared_secret);
173 EVP_DigestInit(&md, evp_md);
174 EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
175 EVP_DigestFinal(&md, digest, NULL);
180 dump_digest(digest, evp_md->md_size);
186 derive_key(int id, int need, char unsigned *hash, BIGNUM *shared_secret)
189 EVP_MD *evp_md = EVP_sha1();
193 int mdsz = evp_md->md_size;
194 unsigned char *digest = xmalloc(((need+mdsz-1)/mdsz)*mdsz);
197 buffer_put_bignum2(&b, shared_secret);
199 EVP_DigestInit(&md, evp_md);
200 EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); /* shared_secret K */
201 EVP_DigestUpdate(&md, hash, mdsz); /* transport-06 */
202 EVP_DigestUpdate(&md, &c, 1); /* key id */
203 EVP_DigestUpdate(&md, hash, mdsz); /* session id */
204 EVP_DigestFinal(&md, digest, NULL);
207 for (have = mdsz; need > have; have += mdsz) {
208 EVP_DigestInit(&md, evp_md);
209 EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
210 EVP_DigestUpdate(&md, hash, mdsz);
211 EVP_DigestUpdate(&md, digest, have);
212 EVP_DigestFinal(&md, digest + have, NULL);
216 fprintf(stderr, "Digest '%c'== ", c);
217 dump_digest(digest, need);
228 get_match(char *client, char *server)
230 char *sproposals[MAX_PROP];
232 int i, j, nproposals;
234 for ((p = strtok(server, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) {
242 for ((p = strtok(client, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) {
243 for (j = 0; j < nproposals; j++)
244 if (strcmp(p, sproposals[j]) == 0)
250 choose_enc(Enc *enc, char *client, char *server)
252 char *name = get_match(client, server);
254 fatal("no matching cipher found: client %s server %s", client, server);
255 enc->type = cipher_number(name);
258 case SSH_CIPHER_3DES_CBC:
263 case SSH_CIPHER_BLOWFISH_CBC:
264 case SSH_CIPHER_CAST128_CBC:
269 case SSH_CIPHER_ARCFOUR:
275 fatal("unsupported cipher %s", name);
283 choose_mac(Mac *mac, char *client, char *server)
285 char *name = get_match(client, server);
287 fatal("no matching mac found: client %s server %s", client, server);
288 if (strcmp(name, "hmac-md5") == 0) {
290 } else if (strcmp(name, "hmac-sha1") == 0) {
291 mac->md = EVP_sha1();
292 } else if (strcmp(name, "hmac-ripemd160@openssh.com") == 0) {
293 mac->md = EVP_ripemd160();
295 fatal("unsupported mac %s", name);
298 mac->mac_len = mac->md->md_size;
299 mac->key_len = datafellows ? 16 : mac->mac_len;
304 choose_comp(Comp *comp, char *client, char *server)
306 char *name = get_match(client, server);
308 fatal("no matching comp found: client %s server %s", client, server);
309 if (strcmp(name, "zlib") == 0) {
311 } else if (strcmp(name, "none") == 0) {
314 fatal("unsupported comp %s", name);
319 choose_kex(Kex *k, char *client, char *server)
321 k->name = get_match(client, server);
324 if (strcmp(k->name, KEX_DH1) != 0)
325 fatal("bad kex alg %s", k->name);
328 choose_hostkeyalg(Kex *k, char *client, char *server)
330 k->hostkeyalg = get_match(client, server);
331 if (k->hostkeyalg == NULL)
332 fatal("no hostkey alg");
333 if (strcmp(k->hostkeyalg, KEX_DSS) != 0)
334 fatal("bad hostkey alg %s", k->hostkeyalg);
338 kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server)
342 int ctos; /* direction: if true client-to-server */
346 k = xmalloc(sizeof(*k));
347 memset(k, 0, sizeof(*k));
350 for (mode = 0; mode < MODE_MAX; mode++) {
351 int nenc, nmac, ncomp;
352 ctos = (!k->server && mode == MODE_OUT) || (k->server && mode == MODE_IN);
353 nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC;
354 nmac = ctos ? PROPOSAL_MAC_ALGS_CTOS : PROPOSAL_MAC_ALGS_STOC;
355 ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC;
356 choose_enc (&k->enc [mode], cprop[nenc], sprop[nenc]);
357 choose_mac (&k->mac [mode], cprop[nmac], sprop[nmac]);
358 choose_comp(&k->comp[mode], cprop[ncomp], sprop[ncomp]);
359 log("kex: %s %s %s %s",
360 ctos ? "client->server" : "server->client",
365 choose_kex(k, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]);
366 choose_hostkeyalg(k, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
367 sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]);
368 for (i = 0; i < PROPOSAL_MAX; i++) {
373 for (mode = 0; mode < MODE_MAX; mode++) {
374 if (need < k->enc[mode].key_len)
375 need = k->enc[mode].key_len;
376 if (need < k->enc[mode].iv_len)
377 need = k->enc[mode].iv_len;
378 if (need < k->mac[mode].key_len)
379 need = k->mac[mode].key_len;
383 k->we_need = WE_NEED;
389 kex_derive_keys(Kex *k, unsigned char *hash, BIGNUM *shared_secret)
394 unsigned char *keys[NKEYS];
396 for (i = 0; i < NKEYS; i++)
397 keys[i] = derive_key('A'+i, k->we_need, hash, shared_secret);
399 for (mode = 0; mode < MODE_MAX; mode++) {
400 ctos = (!k->server && mode == MODE_OUT) || (k->server && mode == MODE_IN);
401 k->enc[mode].iv = keys[ctos ? 0 : 1];
402 k->enc[mode].key = keys[ctos ? 2 : 3];
403 k->mac[mode].key = keys[ctos ? 4 : 5];