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1 | /* | |
2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
4 | * All rights reserved | |
5 | * | |
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. | |
14 | * Copyright (c) 1999, 2000 Markus Friedl. All rights reserved. | |
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. | |
24 | * | |
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. | |
35 | */ | |
36 | ||
37 | #include "includes.h" | |
38 | RCSID("$OpenBSD: cipher.c,v 1.60 2002/06/23 03:26:52 deraadt Exp $"); | |
39 | ||
40 | #include "xmalloc.h" | |
41 | #include "log.h" | |
42 | #include "cipher.h" | |
43 | ||
44 | #include <openssl/md5.h> | |
45 | ||
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 | ||
51 | #if OPENSSL_VERSION_NUMBER < 0x00907000L | |
52 | #include "rijndael.h" | |
53 | static const EVP_CIPHER *evp_rijndael(void); | |
54 | #endif | |
55 | static const EVP_CIPHER *evp_ssh1_3des(void); | |
56 | static const EVP_CIPHER *evp_ssh1_bf(void); | |
57 | ||
58 | struct Cipher { | |
59 | char *name; | |
60 | int number; /* for ssh1 only */ | |
61 | u_int block_size; | |
62 | u_int key_len; | |
63 | const EVP_CIPHER *(*evptype)(void); | |
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 }, | |
74 | #if OPENSSL_VERSION_NUMBER < 0x00907000L | |
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 }, | |
78 | { "rijndael-cbc@lysator.liu.se", | |
79 | SSH_CIPHER_SSH2, 16, 32, evp_rijndael }, | |
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 | |
87 | ||
88 | { NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL } | |
89 | }; | |
90 | ||
91 | /*--*/ | |
92 | ||
93 | u_int | |
94 | cipher_blocksize(Cipher *c) | |
95 | { | |
96 | return (c->block_size); | |
97 | } | |
98 | ||
99 | u_int | |
100 | cipher_keylen(Cipher *c) | |
101 | { | |
102 | return (c->key_len); | |
103 | } | |
104 | ||
105 | u_int | |
106 | cipher_get_number(Cipher *c) | |
107 | { | |
108 | return (c->number); | |
109 | } | |
110 | ||
111 | u_int | |
112 | cipher_mask_ssh1(int client) | |
113 | { | |
114 | u_int mask = 0; | |
115 | mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ | |
116 | mask |= 1 << SSH_CIPHER_BLOWFISH; | |
117 | if (client) { | |
118 | mask |= 1 << SSH_CIPHER_DES; | |
119 | } | |
120 | return mask; | |
121 | } | |
122 | ||
123 | Cipher * | |
124 | cipher_by_name(const char *name) | |
125 | { | |
126 | Cipher *c; | |
127 | for (c = ciphers; c->name != NULL; c++) | |
128 | if (strcasecmp(c->name, name) == 0) | |
129 | return c; | |
130 | return NULL; | |
131 | } | |
132 | ||
133 | Cipher * | |
134 | cipher_by_number(int id) | |
135 | { | |
136 | Cipher *c; | |
137 | for (c = ciphers; c->name != NULL; c++) | |
138 | if (c->number == id) | |
139 | return c; | |
140 | return NULL; | |
141 | } | |
142 | ||
143 | #define CIPHER_SEP "," | |
144 | int | |
145 | ciphers_valid(const char *names) | |
146 | { | |
147 | Cipher *c; | |
148 | char *ciphers, *cp; | |
149 | char *p; | |
150 | ||
151 | if (names == NULL || strcmp(names, "") == 0) | |
152 | return 0; | |
153 | ciphers = cp = xstrdup(names); | |
154 | for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0'; | |
155 | (p = strsep(&cp, CIPHER_SEP))) { | |
156 | c = cipher_by_name(p); | |
157 | if (c == NULL || c->number != SSH_CIPHER_SSH2) { | |
158 | debug("bad cipher %s [%s]", p, names); | |
159 | xfree(ciphers); | |
160 | return 0; | |
161 | } else { | |
162 | debug3("cipher ok: %s [%s]", p, names); | |
163 | } | |
164 | } | |
165 | debug3("ciphers ok: [%s]", names); | |
166 | xfree(ciphers); | |
167 | return 1; | |
168 | } | |
169 | ||
170 | /* | |
171 | * Parses the name of the cipher. Returns the number of the corresponding | |
172 | * cipher, or -1 on error. | |
173 | */ | |
174 | ||
175 | int | |
176 | cipher_number(const char *name) | |
177 | { | |
178 | Cipher *c; | |
179 | if (name == NULL) | |
180 | return -1; | |
181 | c = cipher_by_name(name); | |
182 | return (c==NULL) ? -1 : c->number; | |
183 | } | |
184 | ||
185 | char * | |
186 | cipher_name(int id) | |
187 | { | |
188 | Cipher *c = cipher_by_number(id); | |
189 | return (c==NULL) ? "<unknown>" : c->name; | |
190 | } | |
191 | ||
192 | void | |
193 | cipher_init(CipherContext *cc, Cipher *cipher, | |
194 | const u_char *key, u_int keylen, const u_char *iv, u_int ivlen, | |
195 | int encrypt) | |
196 | { | |
197 | static int dowarn = 1; | |
198 | #ifdef SSH_OLD_EVP | |
199 | EVP_CIPHER *type; | |
200 | #else | |
201 | const EVP_CIPHER *type; | |
202 | #endif | |
203 | int klen; | |
204 | ||
205 | if (cipher->number == SSH_CIPHER_DES) { | |
206 | if (dowarn) { | |
207 | error("Warning: use of DES is strongly discouraged " | |
208 | "due to cryptographic weaknesses"); | |
209 | dowarn = 0; | |
210 | } | |
211 | if (keylen > 8) | |
212 | keylen = 8; | |
213 | } | |
214 | cc->plaintext = (cipher->number == SSH_CIPHER_NONE); | |
215 | ||
216 | if (keylen < cipher->key_len) | |
217 | fatal("cipher_init: key length %d is insufficient for %s.", | |
218 | keylen, cipher->name); | |
219 | if (iv != NULL && ivlen < cipher->block_size) | |
220 | fatal("cipher_init: iv length %d is insufficient for %s.", | |
221 | ivlen, cipher->name); | |
222 | cc->cipher = cipher; | |
223 | ||
224 | type = (*cipher->evptype)(); | |
225 | ||
226 | EVP_CIPHER_CTX_init(&cc->evp); | |
227 | #ifdef SSH_OLD_EVP | |
228 | if (type->key_len > 0 && type->key_len != keylen) { | |
229 | debug("cipher_init: set keylen (%d -> %d)", | |
230 | type->key_len, keylen); | |
231 | type->key_len = keylen; | |
232 | } | |
233 | EVP_CipherInit(&cc->evp, type, (u_char *)key, (u_char *)iv, | |
234 | (encrypt == CIPHER_ENCRYPT)); | |
235 | #else | |
236 | if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv, | |
237 | (encrypt == CIPHER_ENCRYPT)) == 0) | |
238 | fatal("cipher_init: EVP_CipherInit failed for %s", | |
239 | cipher->name); | |
240 | klen = EVP_CIPHER_CTX_key_length(&cc->evp); | |
241 | if (klen > 0 && keylen != klen) { | |
242 | debug("cipher_init: set keylen (%d -> %d)", klen, keylen); | |
243 | if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0) | |
244 | fatal("cipher_init: set keylen failed (%d -> %d)", | |
245 | klen, keylen); | |
246 | } | |
247 | if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0) | |
248 | fatal("cipher_init: EVP_CipherInit: set key failed for %s", | |
249 | cipher->name); | |
250 | #endif | |
251 | } | |
252 | ||
253 | void | |
254 | cipher_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len) | |
255 | { | |
256 | if (len % cc->cipher->block_size) | |
257 | fatal("cipher_encrypt: bad plaintext length %d", len); | |
258 | #ifdef SSH_OLD_EVP | |
259 | EVP_Cipher(&cc->evp, dest, (u_char *)src, len); | |
260 | #else | |
261 | if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0) | |
262 | fatal("evp_crypt: EVP_Cipher failed"); | |
263 | #endif | |
264 | } | |
265 | ||
266 | void | |
267 | cipher_cleanup(CipherContext *cc) | |
268 | { | |
269 | #ifdef SSH_OLD_EVP | |
270 | EVP_CIPHER_CTX_cleanup(&cc->evp); | |
271 | #else | |
272 | if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0) | |
273 | error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed"); | |
274 | #endif | |
275 | } | |
276 | ||
277 | /* | |
278 | * Selects the cipher, and keys if by computing the MD5 checksum of the | |
279 | * passphrase and using the resulting 16 bytes as the key. | |
280 | */ | |
281 | ||
282 | void | |
283 | cipher_set_key_string(CipherContext *cc, Cipher *cipher, | |
284 | const char *passphrase, int encrypt) | |
285 | { | |
286 | MD5_CTX md; | |
287 | u_char digest[16]; | |
288 | ||
289 | MD5_Init(&md); | |
290 | MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase)); | |
291 | MD5_Final(digest, &md); | |
292 | ||
293 | cipher_init(cc, cipher, digest, 16, NULL, 0, encrypt); | |
294 | ||
295 | memset(digest, 0, sizeof(digest)); | |
296 | memset(&md, 0, sizeof(md)); | |
297 | } | |
298 | ||
299 | /* Implementations for other non-EVP ciphers */ | |
300 | ||
301 | /* | |
302 | * This is used by SSH1: | |
303 | * | |
304 | * What kind of triple DES are these 2 routines? | |
305 | * | |
306 | * Why is there a redundant initialization vector? | |
307 | * | |
308 | * If only iv3 was used, then, this would till effect have been | |
309 | * outer-cbc. However, there is also a private iv1 == iv2 which | |
310 | * perhaps makes differential analysis easier. On the other hand, the | |
311 | * private iv1 probably makes the CRC-32 attack ineffective. This is a | |
312 | * result of that there is no longer any known iv1 to use when | |
313 | * choosing the X block. | |
314 | */ | |
315 | struct ssh1_3des_ctx | |
316 | { | |
317 | EVP_CIPHER_CTX k1, k2, k3; | |
318 | }; | |
319 | ||
320 | static int | |
321 | ssh1_3des_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, | |
322 | int enc) | |
323 | { | |
324 | struct ssh1_3des_ctx *c; | |
325 | u_char *k1, *k2, *k3; | |
326 | ||
327 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
328 | c = xmalloc(sizeof(*c)); | |
329 | EVP_CIPHER_CTX_set_app_data(ctx, c); | |
330 | } | |
331 | if (key == NULL) | |
332 | return (1); | |
333 | if (enc == -1) | |
334 | enc = ctx->encrypt; | |
335 | k1 = k2 = k3 = (u_char *) key; | |
336 | k2 += 8; | |
337 | if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) { | |
338 | if (enc) | |
339 | k3 += 16; | |
340 | else | |
341 | k1 += 16; | |
342 | } | |
343 | EVP_CIPHER_CTX_init(&c->k1); | |
344 | EVP_CIPHER_CTX_init(&c->k2); | |
345 | EVP_CIPHER_CTX_init(&c->k3); | |
346 | #ifdef SSH_OLD_EVP | |
347 | EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc); | |
348 | EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc); | |
349 | EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc); | |
350 | #else | |
351 | if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 || | |
352 | EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 || | |
353 | EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) { | |
354 | memset(c, 0, sizeof(*c)); | |
355 | xfree(c); | |
356 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); | |
357 | return (0); | |
358 | } | |
359 | #endif | |
360 | return (1); | |
361 | } | |
362 | ||
363 | static int | |
364 | ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, u_int len) | |
365 | { | |
366 | struct ssh1_3des_ctx *c; | |
367 | ||
368 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
369 | error("ssh1_3des_cbc: no context"); | |
370 | return (0); | |
371 | } | |
372 | #ifdef SSH_OLD_EVP | |
373 | EVP_Cipher(&c->k1, dest, (u_char *)src, len); | |
374 | EVP_Cipher(&c->k2, dest, dest, len); | |
375 | EVP_Cipher(&c->k3, dest, dest, len); | |
376 | #else | |
377 | if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 || | |
378 | EVP_Cipher(&c->k2, dest, dest, len) == 0 || | |
379 | EVP_Cipher(&c->k3, dest, dest, len) == 0) | |
380 | return (0); | |
381 | #endif | |
382 | return (1); | |
383 | } | |
384 | ||
385 | static int | |
386 | ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx) | |
387 | { | |
388 | struct ssh1_3des_ctx *c; | |
389 | ||
390 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { | |
391 | memset(c, 0, sizeof(*c)); | |
392 | xfree(c); | |
393 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); | |
394 | } | |
395 | return (1); | |
396 | } | |
397 | ||
398 | static const EVP_CIPHER * | |
399 | evp_ssh1_3des(void) | |
400 | { | |
401 | static EVP_CIPHER ssh1_3des; | |
402 | ||
403 | memset(&ssh1_3des, 0, sizeof(EVP_CIPHER)); | |
404 | ssh1_3des.nid = NID_undef; | |
405 | ssh1_3des.block_size = 8; | |
406 | ssh1_3des.iv_len = 0; | |
407 | ssh1_3des.key_len = 16; | |
408 | ssh1_3des.init = ssh1_3des_init; | |
409 | ssh1_3des.cleanup = ssh1_3des_cleanup; | |
410 | ssh1_3des.do_cipher = ssh1_3des_cbc; | |
411 | #ifndef SSH_OLD_EVP | |
412 | ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH; | |
413 | #endif | |
414 | return (&ssh1_3des); | |
415 | } | |
416 | ||
417 | /* | |
418 | * SSH1 uses a variation on Blowfish, all bytes must be swapped before | |
419 | * and after encryption/decryption. Thus the swap_bytes stuff (yuk). | |
420 | */ | |
421 | static void | |
422 | swap_bytes(const u_char *src, u_char *dst, int n) | |
423 | { | |
424 | u_char c[4]; | |
425 | ||
426 | /* Process 4 bytes every lap. */ | |
427 | for (n = n / 4; n > 0; n--) { | |
428 | c[3] = *src++; | |
429 | c[2] = *src++; | |
430 | c[1] = *src++; | |
431 | c[0] = *src++; | |
432 | ||
433 | *dst++ = c[0]; | |
434 | *dst++ = c[1]; | |
435 | *dst++ = c[2]; | |
436 | *dst++ = c[3]; | |
437 | } | |
438 | } | |
439 | ||
440 | static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL; | |
441 | ||
442 | static int | |
443 | bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len) | |
444 | { | |
445 | int ret; | |
446 | ||
447 | swap_bytes(in, out, len); | |
448 | ret = (*orig_bf)(ctx, out, out, len); | |
449 | swap_bytes(out, out, len); | |
450 | return (ret); | |
451 | } | |
452 | ||
453 | static const EVP_CIPHER * | |
454 | evp_ssh1_bf(void) | |
455 | { | |
456 | static EVP_CIPHER ssh1_bf; | |
457 | ||
458 | memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER)); | |
459 | orig_bf = ssh1_bf.do_cipher; | |
460 | ssh1_bf.nid = NID_undef; | |
461 | ssh1_bf.do_cipher = bf_ssh1_cipher; | |
462 | ssh1_bf.key_len = 32; | |
463 | return (&ssh1_bf); | |
464 | } | |
465 | ||
466 | #if OPENSSL_VERSION_NUMBER < 0x00907000L | |
467 | /* RIJNDAEL */ | |
468 | #define RIJNDAEL_BLOCKSIZE 16 | |
469 | struct ssh_rijndael_ctx | |
470 | { | |
471 | rijndael_ctx r_ctx; | |
472 | u_char r_iv[RIJNDAEL_BLOCKSIZE]; | |
473 | }; | |
474 | ||
475 | static int | |
476 | ssh_rijndael_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, | |
477 | int enc) | |
478 | { | |
479 | struct ssh_rijndael_ctx *c; | |
480 | ||
481 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
482 | c = xmalloc(sizeof(*c)); | |
483 | EVP_CIPHER_CTX_set_app_data(ctx, c); | |
484 | } | |
485 | if (key != NULL) { | |
486 | if (enc == -1) | |
487 | enc = ctx->encrypt; | |
488 | rijndael_set_key(&c->r_ctx, (u_char *)key, | |
489 | 8*EVP_CIPHER_CTX_key_length(ctx), enc); | |
490 | } | |
491 | if (iv != NULL) | |
492 | memcpy(c->r_iv, iv, RIJNDAEL_BLOCKSIZE); | |
493 | return (1); | |
494 | } | |
495 | ||
496 | static int | |
497 | ssh_rijndael_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, | |
498 | u_int len) | |
499 | { | |
500 | struct ssh_rijndael_ctx *c; | |
501 | u_char buf[RIJNDAEL_BLOCKSIZE]; | |
502 | u_char *cprev, *cnow, *plain, *ivp; | |
503 | int i, j, blocks = len / RIJNDAEL_BLOCKSIZE; | |
504 | ||
505 | if (len == 0) | |
506 | return (1); | |
507 | if (len % RIJNDAEL_BLOCKSIZE) | |
508 | fatal("ssh_rijndael_cbc: bad len %d", len); | |
509 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
510 | error("ssh_rijndael_cbc: no context"); | |
511 | return (0); | |
512 | } | |
513 | if (ctx->encrypt) { | |
514 | cnow = dest; | |
515 | plain = (u_char *)src; | |
516 | cprev = c->r_iv; | |
517 | for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE, | |
518 | cnow+=RIJNDAEL_BLOCKSIZE) { | |
519 | for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) | |
520 | buf[j] = plain[j] ^ cprev[j]; | |
521 | rijndael_encrypt(&c->r_ctx, buf, cnow); | |
522 | cprev = cnow; | |
523 | } | |
524 | memcpy(c->r_iv, cprev, RIJNDAEL_BLOCKSIZE); | |
525 | } else { | |
526 | cnow = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE); | |
527 | plain = dest+len-RIJNDAEL_BLOCKSIZE; | |
528 | ||
529 | memcpy(buf, cnow, RIJNDAEL_BLOCKSIZE); | |
530 | for (i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE, | |
531 | plain-=RIJNDAEL_BLOCKSIZE) { | |
532 | rijndael_decrypt(&c->r_ctx, cnow, plain); | |
533 | ivp = (i == 1) ? c->r_iv : cnow-RIJNDAEL_BLOCKSIZE; | |
534 | for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) | |
535 | plain[j] ^= ivp[j]; | |
536 | } | |
537 | memcpy(c->r_iv, buf, RIJNDAEL_BLOCKSIZE); | |
538 | } | |
539 | return (1); | |
540 | } | |
541 | ||
542 | static int | |
543 | ssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx) | |
544 | { | |
545 | struct ssh_rijndael_ctx *c; | |
546 | ||
547 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { | |
548 | memset(c, 0, sizeof(*c)); | |
549 | xfree(c); | |
550 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); | |
551 | } | |
552 | return (1); | |
553 | } | |
554 | ||
555 | static const EVP_CIPHER * | |
556 | evp_rijndael(void) | |
557 | { | |
558 | static EVP_CIPHER rijndal_cbc; | |
559 | ||
560 | memset(&rijndal_cbc, 0, sizeof(EVP_CIPHER)); | |
561 | rijndal_cbc.nid = NID_undef; | |
562 | rijndal_cbc.block_size = RIJNDAEL_BLOCKSIZE; | |
563 | rijndal_cbc.iv_len = RIJNDAEL_BLOCKSIZE; | |
564 | rijndal_cbc.key_len = 16; | |
565 | rijndal_cbc.init = ssh_rijndael_init; | |
566 | rijndal_cbc.cleanup = ssh_rijndael_cleanup; | |
567 | rijndal_cbc.do_cipher = ssh_rijndael_cbc; | |
568 | #ifndef SSH_OLD_EVP | |
569 | rijndal_cbc.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH | | |
570 | EVP_CIPH_ALWAYS_CALL_INIT; | |
571 | #endif | |
572 | return (&rijndal_cbc); | |
573 | } | |
574 | #endif | |
575 | ||
576 | /* | |
577 | * Exports an IV from the CipherContext required to export the key | |
578 | * state back from the unprivileged child to the privileged parent | |
579 | * process. | |
580 | */ | |
581 | ||
582 | int | |
583 | cipher_get_keyiv_len(CipherContext *cc) | |
584 | { | |
585 | Cipher *c = cc->cipher; | |
586 | int ivlen; | |
587 | ||
588 | if (c->number == SSH_CIPHER_3DES) | |
589 | ivlen = 24; | |
590 | else | |
591 | ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp); | |
592 | return (ivlen); | |
593 | } | |
594 | ||
595 | void | |
596 | cipher_get_keyiv(CipherContext *cc, u_char *iv, u_int len) | |
597 | { | |
598 | Cipher *c = cc->cipher; | |
599 | u_char *civ = NULL; | |
600 | int evplen; | |
601 | ||
602 | switch (c->number) { | |
603 | case SSH_CIPHER_SSH2: | |
604 | case SSH_CIPHER_DES: | |
605 | case SSH_CIPHER_BLOWFISH: | |
606 | evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); | |
607 | if (evplen == 0) | |
608 | return; | |
609 | if (evplen != len) | |
610 | fatal("%s: wrong iv length %d != %d", __func__, | |
611 | evplen, len); | |
612 | ||
613 | #if OPENSSL_VERSION_NUMBER < 0x00907000L | |
614 | if (c->evptype == evp_rijndael) { | |
615 | struct ssh_rijndael_ctx *aesc; | |
616 | ||
617 | aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
618 | if (aesc == NULL) | |
619 | fatal("%s: no rijndael context", __func__); | |
620 | civ = aesc->r_iv; | |
621 | } else | |
622 | #endif | |
623 | { | |
624 | civ = cc->evp.iv; | |
625 | } | |
626 | break; | |
627 | case SSH_CIPHER_3DES: { | |
628 | struct ssh1_3des_ctx *desc; | |
629 | if (len != 24) | |
630 | fatal("%s: bad 3des iv length: %d", __func__, len); | |
631 | desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
632 | if (desc == NULL) | |
633 | fatal("%s: no 3des context", __func__); | |
634 | debug3("%s: Copying 3DES IV", __func__); | |
635 | memcpy(iv, desc->k1.iv, 8); | |
636 | memcpy(iv + 8, desc->k2.iv, 8); | |
637 | memcpy(iv + 16, desc->k3.iv, 8); | |
638 | return; | |
639 | } | |
640 | default: | |
641 | fatal("%s: bad cipher %d", __func__, c->number); | |
642 | } | |
643 | memcpy(iv, civ, len); | |
644 | } | |
645 | ||
646 | void | |
647 | cipher_set_keyiv(CipherContext *cc, u_char *iv) | |
648 | { | |
649 | Cipher *c = cc->cipher; | |
650 | u_char *div = NULL; | |
651 | int evplen = 0; | |
652 | ||
653 | switch (c->number) { | |
654 | case SSH_CIPHER_SSH2: | |
655 | case SSH_CIPHER_DES: | |
656 | case SSH_CIPHER_BLOWFISH: | |
657 | evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); | |
658 | if (evplen == 0) | |
659 | return; | |
660 | ||
661 | #if OPENSSL_VERSION_NUMBER < 0x00907000L | |
662 | if (c->evptype == evp_rijndael) { | |
663 | struct ssh_rijndael_ctx *aesc; | |
664 | ||
665 | aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
666 | if (aesc == NULL) | |
667 | fatal("%s: no rijndael context", __func__); | |
668 | div = aesc->r_iv; | |
669 | } else | |
670 | #endif | |
671 | { | |
672 | div = cc->evp.iv; | |
673 | } | |
674 | break; | |
675 | case SSH_CIPHER_3DES: { | |
676 | struct ssh1_3des_ctx *desc; | |
677 | desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
678 | if (desc == NULL) | |
679 | fatal("%s: no 3des context", __func__); | |
680 | debug3("%s: Installed 3DES IV", __func__); | |
681 | memcpy(desc->k1.iv, iv, 8); | |
682 | memcpy(desc->k2.iv, iv + 8, 8); | |
683 | memcpy(desc->k3.iv, iv + 16, 8); | |
684 | return; | |
685 | } | |
686 | default: | |
687 | fatal("%s: bad cipher %d", __func__, c->number); | |
688 | } | |
689 | memcpy(div, iv, evplen); | |
690 | } | |
691 | ||
692 | #if OPENSSL_VERSION_NUMBER < 0x00907000L | |
693 | #define EVP_X_STATE(evp) &(evp).c | |
694 | #define EVP_X_STATE_LEN(evp) sizeof((evp).c) | |
695 | #else | |
696 | #define EVP_X_STATE(evp) (evp).cipher_data | |
697 | #define EVP_X_STATE_LEN(evp) (evp).cipher->ctx_size | |
698 | #endif | |
699 | ||
700 | int | |
701 | cipher_get_keycontext(CipherContext *cc, u_char *dat) | |
702 | { | |
703 | Cipher *c = cc->cipher; | |
704 | int plen = 0; | |
705 | ||
706 | if (c->evptype == EVP_rc4) { | |
707 | plen = EVP_X_STATE_LEN(cc->evp); | |
708 | if (dat == NULL) | |
709 | return (plen); | |
710 | memcpy(dat, EVP_X_STATE(cc->evp), plen); | |
711 | } | |
712 | return (plen); | |
713 | } | |
714 | ||
715 | void | |
716 | cipher_set_keycontext(CipherContext *cc, u_char *dat) | |
717 | { | |
718 | Cipher *c = cc->cipher; | |
719 | int plen; | |
720 | ||
721 | if (c->evptype == EVP_rc4) { | |
722 | plen = EVP_X_STATE_LEN(cc->evp); | |
723 | memcpy(EVP_X_STATE(cc->evp), dat, plen); | |
724 | } | |
725 | } |