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8efc0c15 | 1 | /* |
5260325f | 2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
5260325f | 3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
4 | * All rights reserved | |
6ae2364d | 5 | * |
bcbf86ec | 6 | * As far as I am concerned, the code I have written for this software |
7 | * can be used freely for any purpose. Any derived versions of this | |
8 | * software must be clearly marked as such, and if the derived work is | |
9 | * incompatible with the protocol description in the RFC file, it must be | |
10 | * called by a name other than "ssh" or "Secure Shell". | |
11 | * | |
12 | * | |
13 | * Copyright (c) 1999 Niels Provos. All rights reserved. | |
a96070d4 | 14 | * Copyright (c) 1999, 2000 Markus Friedl. All rights reserved. |
bcbf86ec | 15 | * |
16 | * Redistribution and use in source and binary forms, with or without | |
17 | * modification, are permitted provided that the following conditions | |
18 | * are met: | |
19 | * 1. Redistributions of source code must retain the above copyright | |
20 | * notice, this list of conditions and the following disclaimer. | |
21 | * 2. Redistributions in binary form must reproduce the above copyright | |
22 | * notice, this list of conditions and the following disclaimer in the | |
23 | * documentation and/or other materials provided with the distribution. | |
6ae2364d | 24 | * |
bcbf86ec | 25 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
26 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
27 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
28 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
29 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
30 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
31 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
32 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
33 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
34 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
5260325f | 35 | */ |
8efc0c15 | 36 | |
37 | #include "includes.h" | |
135247df | 38 | RCSID("$OpenBSD: cipher.c,v 1.57 2002/05/30 08:07:31 markus Exp $"); |
8efc0c15 | 39 | |
a8be9f80 | 40 | #include "xmalloc.h" |
42f11eb2 | 41 | #include "log.h" |
42 | #include "cipher.h" | |
8efc0c15 | 43 | |
44 | #include <openssl/md5.h> | |
70fc1609 | 45 | |
a068d86f | 46 | #if OPENSSL_VERSION_NUMBER < 0x00906000L |
47 | #define SSH_OLD_EVP | |
48 | #define EVP_CIPHER_CTX_get_app_data(e) ((e)->app_data) | |
49 | #endif | |
50 | ||
135247df | 51 | #if OPENSSL_VERSION_NUMBER < 0x00907000L |
52 | #include "rijndael.h" | |
53 | static const EVP_CIPHER *evp_rijndael(void); | |
54 | #endif | |
7b5edc2b | 55 | static const EVP_CIPHER *evp_ssh1_3des(void); |
56 | static const EVP_CIPHER *evp_ssh1_bf(void); | |
8efc0c15 | 57 | |
3ee832e5 | 58 | struct Cipher { |
59 | char *name; | |
60 | int number; /* for ssh1 only */ | |
61 | u_int block_size; | |
62 | u_int key_len; | |
7b5edc2b | 63 | const EVP_CIPHER *(*evptype)(void); |
70fc1609 | 64 | } ciphers[] = { |
65 | { "none", SSH_CIPHER_NONE, 8, 0, EVP_enc_null }, | |
66 | { "des", SSH_CIPHER_DES, 8, 8, EVP_des_cbc }, | |
67 | { "3des", SSH_CIPHER_3DES, 8, 16, evp_ssh1_3des }, | |
68 | { "blowfish", SSH_CIPHER_BLOWFISH, 8, 32, evp_ssh1_bf }, | |
69 | ||
70 | { "3des-cbc", SSH_CIPHER_SSH2, 8, 24, EVP_des_ede3_cbc }, | |
71 | { "blowfish-cbc", SSH_CIPHER_SSH2, 8, 16, EVP_bf_cbc }, | |
72 | { "cast128-cbc", SSH_CIPHER_SSH2, 8, 16, EVP_cast5_cbc }, | |
73 | { "arcfour", SSH_CIPHER_SSH2, 8, 16, EVP_rc4 }, | |
135247df | 74 | #if OPENSSL_VERSION_NUMBER < 0x00907000L |
70fc1609 | 75 | { "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, evp_rijndael }, |
76 | { "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, evp_rijndael }, | |
77 | { "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, evp_rijndael }, | |
bf03f2da | 78 | { "rijndael-cbc@lysator.liu.se", |
79 | SSH_CIPHER_SSH2, 16, 32, evp_rijndael }, | |
135247df | 80 | #else |
81 | { "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, EVP_aes_128_cbc }, | |
82 | { "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, EVP_aes_192_cbc }, | |
83 | { "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, EVP_aes_256_cbc }, | |
84 | { "rijndael-cbc@lysator.liu.se", | |
85 | SSH_CIPHER_SSH2, 16, 32, EVP_aes_256_cbc }, | |
86 | #endif | |
70fc1609 | 87 | |
88 | { NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL } | |
94ec8c6b | 89 | }; |
90 | ||
91 | /*--*/ | |
92 | ||
762715ce | 93 | u_int |
3ee832e5 | 94 | cipher_blocksize(Cipher *c) |
95 | { | |
96 | return (c->block_size); | |
97 | } | |
762715ce | 98 | u_int |
3ee832e5 | 99 | cipher_keylen(Cipher *c) |
100 | { | |
101 | return (c->key_len); | |
102 | } | |
762715ce | 103 | u_int |
bf8269a9 | 104 | cipher_get_number(Cipher *c) |
105 | { | |
106 | return (c->number); | |
107 | } | |
3ee832e5 | 108 | |
1e3b8b07 | 109 | u_int |
94ec8c6b | 110 | cipher_mask_ssh1(int client) |
8ce64345 | 111 | { |
1e3b8b07 | 112 | u_int mask = 0; |
184eed6a | 113 | mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ |
94ec8c6b | 114 | mask |= 1 << SSH_CIPHER_BLOWFISH; |
115 | if (client) { | |
116 | mask |= 1 << SSH_CIPHER_DES; | |
117 | } | |
5260325f | 118 | return mask; |
8efc0c15 | 119 | } |
94ec8c6b | 120 | |
121 | Cipher * | |
122 | cipher_by_name(const char *name) | |
8ce64345 | 123 | { |
94ec8c6b | 124 | Cipher *c; |
125 | for (c = ciphers; c->name != NULL; c++) | |
126 | if (strcasecmp(c->name, name) == 0) | |
127 | return c; | |
128 | return NULL; | |
8ce64345 | 129 | } |
8efc0c15 | 130 | |
94ec8c6b | 131 | Cipher * |
132 | cipher_by_number(int id) | |
8efc0c15 | 133 | { |
94ec8c6b | 134 | Cipher *c; |
135 | for (c = ciphers; c->name != NULL; c++) | |
136 | if (c->number == id) | |
137 | return c; | |
138 | return NULL; | |
8efc0c15 | 139 | } |
140 | ||
a8be9f80 | 141 | #define CIPHER_SEP "," |
142 | int | |
143 | ciphers_valid(const char *names) | |
144 | { | |
94ec8c6b | 145 | Cipher *c; |
089fbbd2 | 146 | char *ciphers, *cp; |
a8be9f80 | 147 | char *p; |
a8be9f80 | 148 | |
71276795 | 149 | if (names == NULL || strcmp(names, "") == 0) |
a8be9f80 | 150 | return 0; |
089fbbd2 | 151 | ciphers = cp = xstrdup(names); |
94ec8c6b | 152 | for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0'; |
184eed6a | 153 | (p = strsep(&cp, CIPHER_SEP))) { |
94ec8c6b | 154 | c = cipher_by_name(p); |
155 | if (c == NULL || c->number != SSH_CIPHER_SSH2) { | |
156 | debug("bad cipher %s [%s]", p, names); | |
a8be9f80 | 157 | xfree(ciphers); |
158 | return 0; | |
94ec8c6b | 159 | } else { |
33de75a3 | 160 | debug3("cipher ok: %s [%s]", p, names); |
a8be9f80 | 161 | } |
162 | } | |
33de75a3 | 163 | debug3("ciphers ok: [%s]", names); |
a8be9f80 | 164 | xfree(ciphers); |
165 | return 1; | |
166 | } | |
167 | ||
aa3378df | 168 | /* |
169 | * Parses the name of the cipher. Returns the number of the corresponding | |
170 | * cipher, or -1 on error. | |
171 | */ | |
8efc0c15 | 172 | |
173 | int | |
174 | cipher_number(const char *name) | |
175 | { | |
94ec8c6b | 176 | Cipher *c; |
71276795 | 177 | if (name == NULL) |
178 | return -1; | |
94ec8c6b | 179 | c = cipher_by_name(name); |
180 | return (c==NULL) ? -1 : c->number; | |
181 | } | |
182 | ||
183 | char * | |
184 | cipher_name(int id) | |
185 | { | |
186 | Cipher *c = cipher_by_number(id); | |
187 | return (c==NULL) ? "<unknown>" : c->name; | |
188 | } | |
189 | ||
190 | void | |
70fc1609 | 191 | cipher_init(CipherContext *cc, Cipher *cipher, |
192 | const u_char *key, u_int keylen, const u_char *iv, u_int ivlen, | |
193 | int encrypt) | |
94ec8c6b | 194 | { |
70fc1609 | 195 | static int dowarn = 1; |
a068d86f | 196 | #ifdef SSH_OLD_EVP |
197 | EVP_CIPHER *type; | |
198 | #else | |
70fc1609 | 199 | const EVP_CIPHER *type; |
a068d86f | 200 | #endif |
70fc1609 | 201 | int klen; |
202 | ||
203 | if (cipher->number == SSH_CIPHER_DES) { | |
204 | if (dowarn) { | |
205 | error("Warning: use of DES is strongly discouraged " | |
206 | "due to cryptographic weaknesses"); | |
207 | dowarn = 0; | |
208 | } | |
209 | if (keylen > 8) | |
210 | keylen = 8; | |
211 | } | |
212 | cc->plaintext = (cipher->number == SSH_CIPHER_NONE); | |
213 | ||
94ec8c6b | 214 | if (keylen < cipher->key_len) |
215 | fatal("cipher_init: key length %d is insufficient for %s.", | |
216 | keylen, cipher->name); | |
217 | if (iv != NULL && ivlen < cipher->block_size) | |
218 | fatal("cipher_init: iv length %d is insufficient for %s.", | |
219 | ivlen, cipher->name); | |
220 | cc->cipher = cipher; | |
70fc1609 | 221 | |
222 | type = (*cipher->evptype)(); | |
223 | ||
224 | EVP_CIPHER_CTX_init(&cc->evp); | |
a068d86f | 225 | #ifdef SSH_OLD_EVP |
226 | if (type->key_len > 0 && type->key_len != keylen) { | |
227 | debug("cipher_init: set keylen (%d -> %d)", | |
228 | type->key_len, keylen); | |
229 | type->key_len = keylen; | |
230 | } | |
231 | EVP_CipherInit(&cc->evp, type, (u_char *)key, (u_char *)iv, | |
232 | (encrypt == CIPHER_ENCRYPT)); | |
233 | #else | |
70fc1609 | 234 | if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv, |
235 | (encrypt == CIPHER_ENCRYPT)) == 0) | |
236 | fatal("cipher_init: EVP_CipherInit failed for %s", | |
237 | cipher->name); | |
238 | klen = EVP_CIPHER_CTX_key_length(&cc->evp); | |
239 | if (klen > 0 && keylen != klen) { | |
240 | debug("cipher_init: set keylen (%d -> %d)", klen, keylen); | |
241 | if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0) | |
242 | fatal("cipher_init: set keylen failed (%d -> %d)", | |
243 | klen, keylen); | |
244 | } | |
245 | if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0) | |
246 | fatal("cipher_init: EVP_CipherInit: set key failed for %s", | |
247 | cipher->name); | |
a068d86f | 248 | #endif |
94ec8c6b | 249 | } |
250 | ||
251 | void | |
3ee832e5 | 252 | cipher_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len) |
94ec8c6b | 253 | { |
254 | if (len % cc->cipher->block_size) | |
255 | fatal("cipher_encrypt: bad plaintext length %d", len); | |
a068d86f | 256 | #ifdef SSH_OLD_EVP |
257 | EVP_Cipher(&cc->evp, dest, (u_char *)src, len); | |
258 | #else | |
70fc1609 | 259 | if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0) |
260 | fatal("evp_crypt: EVP_Cipher failed"); | |
a068d86f | 261 | #endif |
94ec8c6b | 262 | } |
263 | ||
264 | void | |
3ee832e5 | 265 | cipher_cleanup(CipherContext *cc) |
94ec8c6b | 266 | { |
a068d86f | 267 | #ifdef SSH_OLD_EVP |
268 | EVP_CIPHER_CTX_cleanup(&cc->evp); | |
269 | #else | |
70fc1609 | 270 | if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0) |
271 | error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed"); | |
a068d86f | 272 | #endif |
8efc0c15 | 273 | } |
274 | ||
aa3378df | 275 | /* |
276 | * Selects the cipher, and keys if by computing the MD5 checksum of the | |
277 | * passphrase and using the resulting 16 bytes as the key. | |
278 | */ | |
8efc0c15 | 279 | |
6ae2364d | 280 | void |
94ec8c6b | 281 | cipher_set_key_string(CipherContext *cc, Cipher *cipher, |
3ee832e5 | 282 | const char *passphrase, int encrypt) |
8efc0c15 | 283 | { |
5260325f | 284 | MD5_CTX md; |
1e3b8b07 | 285 | u_char digest[16]; |
5260325f | 286 | |
287 | MD5_Init(&md); | |
94ec8c6b | 288 | MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase)); |
5260325f | 289 | MD5_Final(digest, &md); |
290 | ||
3ee832e5 | 291 | cipher_init(cc, cipher, digest, 16, NULL, 0, encrypt); |
5260325f | 292 | |
293 | memset(digest, 0, sizeof(digest)); | |
294 | memset(&md, 0, sizeof(md)); | |
8efc0c15 | 295 | } |
70fc1609 | 296 | |
297 | /* Implementations for other non-EVP ciphers */ | |
298 | ||
299 | /* | |
300 | * This is used by SSH1: | |
301 | * | |
302 | * What kind of triple DES are these 2 routines? | |
303 | * | |
304 | * Why is there a redundant initialization vector? | |
305 | * | |
306 | * If only iv3 was used, then, this would till effect have been | |
307 | * outer-cbc. However, there is also a private iv1 == iv2 which | |
308 | * perhaps makes differential analysis easier. On the other hand, the | |
309 | * private iv1 probably makes the CRC-32 attack ineffective. This is a | |
310 | * result of that there is no longer any known iv1 to use when | |
311 | * choosing the X block. | |
312 | */ | |
313 | struct ssh1_3des_ctx | |
314 | { | |
315 | EVP_CIPHER_CTX k1, k2, k3; | |
316 | }; | |
317 | static int | |
318 | ssh1_3des_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, | |
319 | int enc) | |
320 | { | |
321 | struct ssh1_3des_ctx *c; | |
322 | u_char *k1, *k2, *k3; | |
323 | ||
324 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
325 | c = xmalloc(sizeof(*c)); | |
326 | EVP_CIPHER_CTX_set_app_data(ctx, c); | |
327 | } | |
328 | if (key == NULL) | |
329 | return (1); | |
330 | if (enc == -1) | |
331 | enc = ctx->encrypt; | |
332 | k1 = k2 = k3 = (u_char *) key; | |
333 | k2 += 8; | |
334 | if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) { | |
335 | if (enc) | |
336 | k3 += 16; | |
337 | else | |
338 | k1 += 16; | |
339 | } | |
340 | EVP_CIPHER_CTX_init(&c->k1); | |
341 | EVP_CIPHER_CTX_init(&c->k2); | |
342 | EVP_CIPHER_CTX_init(&c->k3); | |
a068d86f | 343 | #ifdef SSH_OLD_EVP |
344 | EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc); | |
345 | EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc); | |
346 | EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc); | |
347 | #else | |
70fc1609 | 348 | if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 || |
349 | EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 || | |
350 | EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) { | |
351 | memset(c, 0, sizeof(*c)); | |
352 | xfree(c); | |
353 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); | |
354 | return (0); | |
355 | } | |
a068d86f | 356 | #endif |
70fc1609 | 357 | return (1); |
358 | } | |
359 | static int | |
360 | ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, u_int len) | |
361 | { | |
362 | struct ssh1_3des_ctx *c; | |
363 | ||
364 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
365 | error("ssh1_3des_cbc: no context"); | |
366 | return (0); | |
367 | } | |
a068d86f | 368 | #ifdef SSH_OLD_EVP |
369 | EVP_Cipher(&c->k1, dest, (u_char *)src, len); | |
370 | EVP_Cipher(&c->k2, dest, dest, len); | |
371 | EVP_Cipher(&c->k3, dest, dest, len); | |
372 | #else | |
70fc1609 | 373 | if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 || |
374 | EVP_Cipher(&c->k2, dest, dest, len) == 0 || | |
375 | EVP_Cipher(&c->k3, dest, dest, len) == 0) | |
376 | return (0); | |
a068d86f | 377 | #endif |
70fc1609 | 378 | return (1); |
379 | } | |
380 | static int | |
381 | ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx) | |
382 | { | |
383 | struct ssh1_3des_ctx *c; | |
384 | ||
385 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { | |
386 | memset(c, 0, sizeof(*c)); | |
387 | xfree(c); | |
388 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); | |
389 | } | |
390 | return (1); | |
391 | } | |
7b5edc2b | 392 | static const EVP_CIPHER * |
70fc1609 | 393 | evp_ssh1_3des(void) |
394 | { | |
395 | static EVP_CIPHER ssh1_3des; | |
396 | ||
397 | memset(&ssh1_3des, 0, sizeof(EVP_CIPHER)); | |
398 | ssh1_3des.nid = NID_undef; | |
399 | ssh1_3des.block_size = 8; | |
400 | ssh1_3des.iv_len = 0; | |
401 | ssh1_3des.key_len = 16; | |
402 | ssh1_3des.init = ssh1_3des_init; | |
403 | ssh1_3des.cleanup = ssh1_3des_cleanup; | |
404 | ssh1_3des.do_cipher = ssh1_3des_cbc; | |
a068d86f | 405 | #ifndef SSH_OLD_EVP |
70fc1609 | 406 | ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH; |
a068d86f | 407 | #endif |
70fc1609 | 408 | return (&ssh1_3des); |
409 | } | |
410 | ||
411 | /* | |
412 | * SSH1 uses a variation on Blowfish, all bytes must be swapped before | |
413 | * and after encryption/decryption. Thus the swap_bytes stuff (yuk). | |
414 | */ | |
415 | static void | |
416 | swap_bytes(const u_char *src, u_char *dst, int n) | |
417 | { | |
418 | u_char c[4]; | |
419 | ||
420 | /* Process 4 bytes every lap. */ | |
421 | for (n = n / 4; n > 0; n--) { | |
422 | c[3] = *src++; | |
423 | c[2] = *src++; | |
424 | c[1] = *src++; | |
425 | c[0] = *src++; | |
426 | ||
427 | *dst++ = c[0]; | |
428 | *dst++ = c[1]; | |
429 | *dst++ = c[2]; | |
430 | *dst++ = c[3]; | |
431 | } | |
432 | } | |
433 | static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL; | |
434 | static int | |
435 | bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len) | |
436 | { | |
437 | int ret; | |
438 | ||
439 | swap_bytes(in, out, len); | |
440 | ret = (*orig_bf)(ctx, out, out, len); | |
441 | swap_bytes(out, out, len); | |
442 | return (ret); | |
443 | } | |
7b5edc2b | 444 | static const EVP_CIPHER * |
70fc1609 | 445 | evp_ssh1_bf(void) |
446 | { | |
447 | static EVP_CIPHER ssh1_bf; | |
448 | ||
449 | memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER)); | |
450 | orig_bf = ssh1_bf.do_cipher; | |
451 | ssh1_bf.nid = NID_undef; | |
452 | ssh1_bf.do_cipher = bf_ssh1_cipher; | |
453 | ssh1_bf.key_len = 32; | |
454 | return (&ssh1_bf); | |
455 | } | |
456 | ||
135247df | 457 | #if OPENSSL_VERSION_NUMBER < 0x00907000L |
70fc1609 | 458 | /* RIJNDAEL */ |
459 | #define RIJNDAEL_BLOCKSIZE 16 | |
460 | struct ssh_rijndael_ctx | |
461 | { | |
462 | rijndael_ctx r_ctx; | |
463 | u_char r_iv[RIJNDAEL_BLOCKSIZE]; | |
464 | }; | |
465 | ||
466 | static int | |
467 | ssh_rijndael_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, | |
468 | int enc) | |
469 | { | |
470 | struct ssh_rijndael_ctx *c; | |
471 | ||
472 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
473 | c = xmalloc(sizeof(*c)); | |
474 | EVP_CIPHER_CTX_set_app_data(ctx, c); | |
475 | } | |
476 | if (key != NULL) { | |
477 | if (enc == -1) | |
478 | enc = ctx->encrypt; | |
479 | rijndael_set_key(&c->r_ctx, (u_char *)key, | |
480 | 8*EVP_CIPHER_CTX_key_length(ctx), enc); | |
481 | } | |
482 | if (iv != NULL) | |
483 | memcpy(c->r_iv, iv, RIJNDAEL_BLOCKSIZE); | |
484 | return (1); | |
485 | } | |
486 | static int | |
487 | ssh_rijndael_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, | |
488 | u_int len) | |
489 | { | |
490 | struct ssh_rijndael_ctx *c; | |
491 | u_char buf[RIJNDAEL_BLOCKSIZE]; | |
492 | u_char *cprev, *cnow, *plain, *ivp; | |
493 | int i, j, blocks = len / RIJNDAEL_BLOCKSIZE; | |
494 | ||
495 | if (len == 0) | |
496 | return (1); | |
497 | if (len % RIJNDAEL_BLOCKSIZE) | |
498 | fatal("ssh_rijndael_cbc: bad len %d", len); | |
499 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
500 | error("ssh_rijndael_cbc: no context"); | |
501 | return (0); | |
502 | } | |
503 | if (ctx->encrypt) { | |
504 | cnow = dest; | |
505 | plain = (u_char *)src; | |
506 | cprev = c->r_iv; | |
507 | for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE, | |
508 | cnow+=RIJNDAEL_BLOCKSIZE) { | |
509 | for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) | |
510 | buf[j] = plain[j] ^ cprev[j]; | |
511 | rijndael_encrypt(&c->r_ctx, buf, cnow); | |
512 | cprev = cnow; | |
513 | } | |
514 | memcpy(c->r_iv, cprev, RIJNDAEL_BLOCKSIZE); | |
515 | } else { | |
516 | cnow = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE); | |
517 | plain = dest+len-RIJNDAEL_BLOCKSIZE; | |
518 | ||
519 | memcpy(buf, cnow, RIJNDAEL_BLOCKSIZE); | |
520 | for (i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE, | |
521 | plain-=RIJNDAEL_BLOCKSIZE) { | |
522 | rijndael_decrypt(&c->r_ctx, cnow, plain); | |
05976246 | 523 | ivp = (i == 1) ? c->r_iv : cnow-RIJNDAEL_BLOCKSIZE; |
524 | for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) | |
525 | plain[j] ^= ivp[j]; | |
526 | } | |
527 | memcpy(c->r_iv, buf, RIJNDAEL_BLOCKSIZE); | |
528 | } | |
529 | return (1); | |
530 | } | |
531 | static int | |
532 | ssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx) | |
533 | { | |
534 | struct ssh_rijndael_ctx *c; | |
535 | ||
536 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { | |
537 | memset(c, 0, sizeof(*c)); | |
538 | xfree(c); | |
539 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); | |
540 | } | |
541 | return (1); | |
542 | } | |
7b5edc2b | 543 | static const EVP_CIPHER * |
05976246 | 544 | evp_rijndael(void) |
545 | { | |
546 | static EVP_CIPHER rijndal_cbc; | |
547 | ||
548 | memset(&rijndal_cbc, 0, sizeof(EVP_CIPHER)); | |
549 | rijndal_cbc.nid = NID_undef; | |
550 | rijndal_cbc.block_size = RIJNDAEL_BLOCKSIZE; | |
551 | rijndal_cbc.iv_len = RIJNDAEL_BLOCKSIZE; | |
552 | rijndal_cbc.key_len = 16; | |
553 | rijndal_cbc.init = ssh_rijndael_init; | |
554 | rijndal_cbc.cleanup = ssh_rijndael_cleanup; | |
555 | rijndal_cbc.do_cipher = ssh_rijndael_cbc; | |
556 | #ifndef SSH_OLD_EVP | |
557 | rijndal_cbc.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH | | |
558 | EVP_CIPH_ALWAYS_CALL_INIT; | |
559 | #endif | |
560 | return (&rijndal_cbc); | |
bf8269a9 | 561 | } |
135247df | 562 | #endif |
bf8269a9 | 563 | |
762715ce | 564 | /* |
bf8269a9 | 565 | * Exports an IV from the CipherContext required to export the key |
566 | * state back from the unprivileged child to the privileged parent | |
567 | * process. | |
568 | */ | |
569 | ||
570 | int | |
571 | cipher_get_keyiv_len(CipherContext *cc) | |
572 | { | |
573 | Cipher *c = cc->cipher; | |
574 | int ivlen; | |
575 | ||
576 | if (c->number == SSH_CIPHER_3DES) | |
577 | ivlen = 24; | |
578 | else | |
579 | ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp); | |
580 | return (ivlen); | |
581 | } | |
582 | ||
583 | void | |
584 | cipher_get_keyiv(CipherContext *cc, u_char *iv, u_int len) | |
585 | { | |
586 | Cipher *c = cc->cipher; | |
587 | u_char *civ = NULL; | |
588 | int evplen; | |
589 | ||
590 | switch (c->number) { | |
591 | case SSH_CIPHER_SSH2: | |
592 | case SSH_CIPHER_DES: | |
593 | case SSH_CIPHER_BLOWFISH: | |
594 | evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); | |
595 | if (evplen == 0) | |
596 | return; | |
597 | if (evplen != len) | |
598 | fatal("%s: wrong iv length %d != %d", __FUNCTION__, | |
599 | evplen, len); | |
600 | ||
135247df | 601 | #if OPENSSL_VERSION_NUMBER < 0x00907000L |
bf03f2da | 602 | if (c->evptype == evp_rijndael) { |
bf8269a9 | 603 | struct ssh_rijndael_ctx *aesc; |
604 | ||
605 | aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
606 | if (aesc == NULL) | |
607 | fatal("%s: no rijndael context", __FUNCTION__); | |
608 | civ = aesc->r_iv; | |
135247df | 609 | } else |
610 | #endif | |
611 | { | |
bf8269a9 | 612 | civ = cc->evp.iv; |
613 | } | |
614 | break; | |
615 | case SSH_CIPHER_3DES: { | |
616 | struct ssh1_3des_ctx *desc; | |
617 | if (len != 24) | |
618 | fatal("%s: bad 3des iv length: %d", __FUNCTION__, len); | |
619 | desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
620 | if (desc == NULL) | |
621 | fatal("%s: no 3des context", __FUNCTION__); | |
622 | debug3("%s: Copying 3DES IV", __FUNCTION__); | |
623 | memcpy(iv, desc->k1.iv, 8); | |
624 | memcpy(iv + 8, desc->k2.iv, 8); | |
625 | memcpy(iv + 16, desc->k3.iv, 8); | |
626 | return; | |
627 | } | |
628 | default: | |
629 | fatal("%s: bad cipher %d", __FUNCTION__, c->number); | |
630 | } | |
631 | memcpy(iv, civ, len); | |
632 | } | |
633 | ||
634 | void | |
635 | cipher_set_keyiv(CipherContext *cc, u_char *iv) | |
636 | { | |
637 | Cipher *c = cc->cipher; | |
638 | u_char *div = NULL; | |
639 | int evplen = 0; | |
640 | ||
641 | switch (c->number) { | |
642 | case SSH_CIPHER_SSH2: | |
643 | case SSH_CIPHER_DES: | |
644 | case SSH_CIPHER_BLOWFISH: | |
645 | evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); | |
646 | if (evplen == 0) | |
647 | return; | |
648 | ||
135247df | 649 | #if OPENSSL_VERSION_NUMBER < 0x00907000L |
bf03f2da | 650 | if (c->evptype == evp_rijndael) { |
bf8269a9 | 651 | struct ssh_rijndael_ctx *aesc; |
652 | ||
653 | aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
654 | if (aesc == NULL) | |
655 | fatal("%s: no rijndael context", __FUNCTION__); | |
656 | div = aesc->r_iv; | |
135247df | 657 | } else |
658 | #endif | |
659 | { | |
bf8269a9 | 660 | div = cc->evp.iv; |
661 | } | |
662 | break; | |
663 | case SSH_CIPHER_3DES: { | |
664 | struct ssh1_3des_ctx *desc; | |
665 | desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
666 | if (desc == NULL) | |
667 | fatal("%s: no 3des context", __FUNCTION__); | |
668 | debug3("%s: Installed 3DES IV", __FUNCTION__); | |
669 | memcpy(desc->k1.iv, iv, 8); | |
670 | memcpy(desc->k2.iv, iv + 8, 8); | |
671 | memcpy(desc->k3.iv, iv + 16, 8); | |
672 | return; | |
762715ce | 673 | } |
bf8269a9 | 674 | default: |
675 | fatal("%s: bad cipher %d", __FUNCTION__, c->number); | |
676 | } | |
677 | memcpy(div, iv, evplen); | |
678 | } | |
679 | ||
680 | #if OPENSSL_VERSION_NUMBER < 0x00907000L | |
681 | #define EVP_X_STATE(evp) &(evp).c | |
682 | #define EVP_X_STATE_LEN(evp) sizeof((evp).c) | |
683 | #else | |
684 | #define EVP_X_STATE(evp) (evp).cipher_data | |
685 | #define EVP_X_STATE_LEN(evp) (evp).cipher->ctx_size | |
686 | #endif | |
687 | ||
688 | int | |
689 | cipher_get_keycontext(CipherContext *cc, u_char *dat) | |
690 | { | |
691 | Cipher *c = cc->cipher; | |
692 | int plen; | |
693 | ||
694 | if (c->number == SSH_CIPHER_3DES) { | |
695 | struct ssh1_3des_ctx *desc; | |
696 | desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
697 | if (desc == NULL) | |
698 | fatal("%s: no 3des context", __FUNCTION__); | |
699 | plen = EVP_X_STATE_LEN(desc->k1); | |
700 | if (dat == NULL) | |
701 | return (3*plen); | |
702 | memcpy(dat, EVP_X_STATE(desc->k1), plen); | |
703 | memcpy(dat + plen, EVP_X_STATE(desc->k2), plen); | |
704 | memcpy(dat + 2*plen, EVP_X_STATE(desc->k3), plen); | |
705 | return (3*plen); | |
706 | } | |
707 | ||
708 | /* Generic EVP */ | |
709 | plen = EVP_X_STATE_LEN(cc->evp); | |
710 | if (dat == NULL) | |
711 | return (plen); | |
712 | ||
713 | memcpy(dat, EVP_X_STATE(cc->evp), plen); | |
714 | return (plen); | |
715 | } | |
716 | ||
717 | void | |
718 | cipher_set_keycontext(CipherContext *cc, u_char *dat) | |
719 | { | |
720 | Cipher *c = cc->cipher; | |
721 | int plen; | |
722 | ||
723 | if (c->number == SSH_CIPHER_3DES) { | |
724 | struct ssh1_3des_ctx *desc; | |
725 | desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
726 | if (desc == NULL) | |
727 | fatal("%s: no 3des context", __FUNCTION__); | |
728 | plen = EVP_X_STATE_LEN(desc->k1); | |
729 | memcpy(EVP_X_STATE(desc->k1), dat, plen); | |
730 | memcpy(EVP_X_STATE(desc->k2), dat + plen, plen); | |
731 | memcpy(EVP_X_STATE(desc->k3), dat + 2*plen, plen); | |
732 | } else { | |
733 | plen = EVP_X_STATE_LEN(cc->evp); | |
734 | memcpy(EVP_X_STATE(cc->evp), dat, plen); | |
735 | } | |
70fc1609 | 736 | } |