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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" | |
70fc1609 | 38 | RCSID("$OpenBSD: cipher.c,v 1.52 2002/02/18 13:05:32 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 | #include "rijndael.h" |
46 | ||
a068d86f | 47 | #if OPENSSL_VERSION_NUMBER < 0x00906000L |
48 | #define SSH_OLD_EVP | |
49 | #define EVP_CIPHER_CTX_get_app_data(e) ((e)->app_data) | |
50 | #endif | |
51 | ||
70fc1609 | 52 | static EVP_CIPHER *evp_ssh1_3des(void); |
53 | static EVP_CIPHER *evp_ssh1_bf(void); | |
54 | static EVP_CIPHER *evp_rijndael(void); | |
8efc0c15 | 55 | |
3ee832e5 | 56 | struct Cipher { |
57 | char *name; | |
58 | int number; /* for ssh1 only */ | |
59 | u_int block_size; | |
60 | u_int key_len; | |
70fc1609 | 61 | EVP_CIPHER *(*evptype)(void); |
62 | } ciphers[] = { | |
63 | { "none", SSH_CIPHER_NONE, 8, 0, EVP_enc_null }, | |
64 | { "des", SSH_CIPHER_DES, 8, 8, EVP_des_cbc }, | |
65 | { "3des", SSH_CIPHER_3DES, 8, 16, evp_ssh1_3des }, | |
66 | { "blowfish", SSH_CIPHER_BLOWFISH, 8, 32, evp_ssh1_bf }, | |
67 | ||
68 | { "3des-cbc", SSH_CIPHER_SSH2, 8, 24, EVP_des_ede3_cbc }, | |
69 | { "blowfish-cbc", SSH_CIPHER_SSH2, 8, 16, EVP_bf_cbc }, | |
70 | { "cast128-cbc", SSH_CIPHER_SSH2, 8, 16, EVP_cast5_cbc }, | |
71 | { "arcfour", SSH_CIPHER_SSH2, 8, 16, EVP_rc4 }, | |
72 | { "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, evp_rijndael }, | |
73 | { "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, evp_rijndael }, | |
74 | { "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, evp_rijndael }, | |
75 | ||
76 | { NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL } | |
94ec8c6b | 77 | }; |
78 | ||
79 | /*--*/ | |
80 | ||
70fc1609 | 81 | u_int |
3ee832e5 | 82 | cipher_blocksize(Cipher *c) |
83 | { | |
84 | return (c->block_size); | |
85 | } | |
70fc1609 | 86 | u_int |
3ee832e5 | 87 | cipher_keylen(Cipher *c) |
88 | { | |
89 | return (c->key_len); | |
90 | } | |
91 | ||
1e3b8b07 | 92 | u_int |
94ec8c6b | 93 | cipher_mask_ssh1(int client) |
8ce64345 | 94 | { |
1e3b8b07 | 95 | u_int mask = 0; |
184eed6a | 96 | mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ |
94ec8c6b | 97 | mask |= 1 << SSH_CIPHER_BLOWFISH; |
98 | if (client) { | |
99 | mask |= 1 << SSH_CIPHER_DES; | |
100 | } | |
5260325f | 101 | return mask; |
8efc0c15 | 102 | } |
94ec8c6b | 103 | |
104 | Cipher * | |
105 | cipher_by_name(const char *name) | |
8ce64345 | 106 | { |
94ec8c6b | 107 | Cipher *c; |
108 | for (c = ciphers; c->name != NULL; c++) | |
109 | if (strcasecmp(c->name, name) == 0) | |
110 | return c; | |
111 | return NULL; | |
8ce64345 | 112 | } |
8efc0c15 | 113 | |
94ec8c6b | 114 | Cipher * |
115 | cipher_by_number(int id) | |
8efc0c15 | 116 | { |
94ec8c6b | 117 | Cipher *c; |
118 | for (c = ciphers; c->name != NULL; c++) | |
119 | if (c->number == id) | |
120 | return c; | |
121 | return NULL; | |
8efc0c15 | 122 | } |
123 | ||
a8be9f80 | 124 | #define CIPHER_SEP "," |
125 | int | |
126 | ciphers_valid(const char *names) | |
127 | { | |
94ec8c6b | 128 | Cipher *c; |
089fbbd2 | 129 | char *ciphers, *cp; |
a8be9f80 | 130 | char *p; |
a8be9f80 | 131 | |
71276795 | 132 | if (names == NULL || strcmp(names, "") == 0) |
a8be9f80 | 133 | return 0; |
089fbbd2 | 134 | ciphers = cp = xstrdup(names); |
94ec8c6b | 135 | for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0'; |
184eed6a | 136 | (p = strsep(&cp, CIPHER_SEP))) { |
94ec8c6b | 137 | c = cipher_by_name(p); |
138 | if (c == NULL || c->number != SSH_CIPHER_SSH2) { | |
139 | debug("bad cipher %s [%s]", p, names); | |
a8be9f80 | 140 | xfree(ciphers); |
141 | return 0; | |
94ec8c6b | 142 | } else { |
33de75a3 | 143 | debug3("cipher ok: %s [%s]", p, names); |
a8be9f80 | 144 | } |
145 | } | |
33de75a3 | 146 | debug3("ciphers ok: [%s]", names); |
a8be9f80 | 147 | xfree(ciphers); |
148 | return 1; | |
149 | } | |
150 | ||
aa3378df | 151 | /* |
152 | * Parses the name of the cipher. Returns the number of the corresponding | |
153 | * cipher, or -1 on error. | |
154 | */ | |
8efc0c15 | 155 | |
156 | int | |
157 | cipher_number(const char *name) | |
158 | { | |
94ec8c6b | 159 | Cipher *c; |
71276795 | 160 | if (name == NULL) |
161 | return -1; | |
94ec8c6b | 162 | c = cipher_by_name(name); |
163 | return (c==NULL) ? -1 : c->number; | |
164 | } | |
165 | ||
166 | char * | |
167 | cipher_name(int id) | |
168 | { | |
169 | Cipher *c = cipher_by_number(id); | |
170 | return (c==NULL) ? "<unknown>" : c->name; | |
171 | } | |
172 | ||
173 | void | |
70fc1609 | 174 | cipher_init(CipherContext *cc, Cipher *cipher, |
175 | const u_char *key, u_int keylen, const u_char *iv, u_int ivlen, | |
176 | int encrypt) | |
94ec8c6b | 177 | { |
70fc1609 | 178 | static int dowarn = 1; |
a068d86f | 179 | #ifdef SSH_OLD_EVP |
180 | EVP_CIPHER *type; | |
181 | #else | |
70fc1609 | 182 | const EVP_CIPHER *type; |
a068d86f | 183 | #endif |
70fc1609 | 184 | int klen; |
185 | ||
186 | if (cipher->number == SSH_CIPHER_DES) { | |
187 | if (dowarn) { | |
188 | error("Warning: use of DES is strongly discouraged " | |
189 | "due to cryptographic weaknesses"); | |
190 | dowarn = 0; | |
191 | } | |
192 | if (keylen > 8) | |
193 | keylen = 8; | |
194 | } | |
195 | cc->plaintext = (cipher->number == SSH_CIPHER_NONE); | |
196 | ||
94ec8c6b | 197 | if (keylen < cipher->key_len) |
198 | fatal("cipher_init: key length %d is insufficient for %s.", | |
199 | keylen, cipher->name); | |
200 | if (iv != NULL && ivlen < cipher->block_size) | |
201 | fatal("cipher_init: iv length %d is insufficient for %s.", | |
202 | ivlen, cipher->name); | |
203 | cc->cipher = cipher; | |
70fc1609 | 204 | |
205 | type = (*cipher->evptype)(); | |
206 | ||
207 | EVP_CIPHER_CTX_init(&cc->evp); | |
a068d86f | 208 | #ifdef SSH_OLD_EVP |
209 | if (type->key_len > 0 && type->key_len != keylen) { | |
210 | debug("cipher_init: set keylen (%d -> %d)", | |
211 | type->key_len, keylen); | |
212 | type->key_len = keylen; | |
213 | } | |
214 | EVP_CipherInit(&cc->evp, type, (u_char *)key, (u_char *)iv, | |
215 | (encrypt == CIPHER_ENCRYPT)); | |
216 | #else | |
70fc1609 | 217 | if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv, |
218 | (encrypt == CIPHER_ENCRYPT)) == 0) | |
219 | fatal("cipher_init: EVP_CipherInit failed for %s", | |
220 | cipher->name); | |
221 | klen = EVP_CIPHER_CTX_key_length(&cc->evp); | |
222 | if (klen > 0 && keylen != klen) { | |
223 | debug("cipher_init: set keylen (%d -> %d)", klen, keylen); | |
224 | if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0) | |
225 | fatal("cipher_init: set keylen failed (%d -> %d)", | |
226 | klen, keylen); | |
227 | } | |
228 | if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0) | |
229 | fatal("cipher_init: EVP_CipherInit: set key failed for %s", | |
230 | cipher->name); | |
a068d86f | 231 | #endif |
94ec8c6b | 232 | } |
233 | ||
234 | void | |
3ee832e5 | 235 | cipher_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len) |
94ec8c6b | 236 | { |
237 | if (len % cc->cipher->block_size) | |
238 | fatal("cipher_encrypt: bad plaintext length %d", len); | |
a068d86f | 239 | #ifdef SSH_OLD_EVP |
240 | EVP_Cipher(&cc->evp, dest, (u_char *)src, len); | |
241 | #else | |
70fc1609 | 242 | if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0) |
243 | fatal("evp_crypt: EVP_Cipher failed"); | |
a068d86f | 244 | #endif |
94ec8c6b | 245 | } |
246 | ||
247 | void | |
3ee832e5 | 248 | cipher_cleanup(CipherContext *cc) |
94ec8c6b | 249 | { |
a068d86f | 250 | #ifdef SSH_OLD_EVP |
251 | EVP_CIPHER_CTX_cleanup(&cc->evp); | |
252 | #else | |
70fc1609 | 253 | if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0) |
254 | error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed"); | |
a068d86f | 255 | #endif |
8efc0c15 | 256 | } |
257 | ||
aa3378df | 258 | /* |
259 | * Selects the cipher, and keys if by computing the MD5 checksum of the | |
260 | * passphrase and using the resulting 16 bytes as the key. | |
261 | */ | |
8efc0c15 | 262 | |
6ae2364d | 263 | void |
94ec8c6b | 264 | cipher_set_key_string(CipherContext *cc, Cipher *cipher, |
3ee832e5 | 265 | const char *passphrase, int encrypt) |
8efc0c15 | 266 | { |
5260325f | 267 | MD5_CTX md; |
1e3b8b07 | 268 | u_char digest[16]; |
5260325f | 269 | |
270 | MD5_Init(&md); | |
94ec8c6b | 271 | MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase)); |
5260325f | 272 | MD5_Final(digest, &md); |
273 | ||
3ee832e5 | 274 | cipher_init(cc, cipher, digest, 16, NULL, 0, encrypt); |
5260325f | 275 | |
276 | memset(digest, 0, sizeof(digest)); | |
277 | memset(&md, 0, sizeof(md)); | |
8efc0c15 | 278 | } |
70fc1609 | 279 | |
280 | /* Implementations for other non-EVP ciphers */ | |
281 | ||
282 | /* | |
283 | * This is used by SSH1: | |
284 | * | |
285 | * What kind of triple DES are these 2 routines? | |
286 | * | |
287 | * Why is there a redundant initialization vector? | |
288 | * | |
289 | * If only iv3 was used, then, this would till effect have been | |
290 | * outer-cbc. However, there is also a private iv1 == iv2 which | |
291 | * perhaps makes differential analysis easier. On the other hand, the | |
292 | * private iv1 probably makes the CRC-32 attack ineffective. This is a | |
293 | * result of that there is no longer any known iv1 to use when | |
294 | * choosing the X block. | |
295 | */ | |
296 | struct ssh1_3des_ctx | |
297 | { | |
298 | EVP_CIPHER_CTX k1, k2, k3; | |
299 | }; | |
300 | static int | |
301 | ssh1_3des_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, | |
302 | int enc) | |
303 | { | |
304 | struct ssh1_3des_ctx *c; | |
305 | u_char *k1, *k2, *k3; | |
306 | ||
307 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
308 | c = xmalloc(sizeof(*c)); | |
309 | EVP_CIPHER_CTX_set_app_data(ctx, c); | |
310 | } | |
311 | if (key == NULL) | |
312 | return (1); | |
313 | if (enc == -1) | |
314 | enc = ctx->encrypt; | |
315 | k1 = k2 = k3 = (u_char *) key; | |
316 | k2 += 8; | |
317 | if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) { | |
318 | if (enc) | |
319 | k3 += 16; | |
320 | else | |
321 | k1 += 16; | |
322 | } | |
323 | EVP_CIPHER_CTX_init(&c->k1); | |
324 | EVP_CIPHER_CTX_init(&c->k2); | |
325 | EVP_CIPHER_CTX_init(&c->k3); | |
a068d86f | 326 | #ifdef SSH_OLD_EVP |
327 | EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc); | |
328 | EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc); | |
329 | EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc); | |
330 | #else | |
70fc1609 | 331 | if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 || |
332 | EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 || | |
333 | EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) { | |
334 | memset(c, 0, sizeof(*c)); | |
335 | xfree(c); | |
336 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); | |
337 | return (0); | |
338 | } | |
a068d86f | 339 | #endif |
70fc1609 | 340 | return (1); |
341 | } | |
342 | static int | |
343 | ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, u_int len) | |
344 | { | |
345 | struct ssh1_3des_ctx *c; | |
346 | ||
347 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
348 | error("ssh1_3des_cbc: no context"); | |
349 | return (0); | |
350 | } | |
a068d86f | 351 | #ifdef SSH_OLD_EVP |
352 | EVP_Cipher(&c->k1, dest, (u_char *)src, len); | |
353 | EVP_Cipher(&c->k2, dest, dest, len); | |
354 | EVP_Cipher(&c->k3, dest, dest, len); | |
355 | #else | |
70fc1609 | 356 | if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 || |
357 | EVP_Cipher(&c->k2, dest, dest, len) == 0 || | |
358 | EVP_Cipher(&c->k3, dest, dest, len) == 0) | |
359 | return (0); | |
a068d86f | 360 | #endif |
70fc1609 | 361 | return (1); |
362 | } | |
363 | static int | |
364 | ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx) | |
365 | { | |
366 | struct ssh1_3des_ctx *c; | |
367 | ||
368 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { | |
369 | memset(c, 0, sizeof(*c)); | |
370 | xfree(c); | |
371 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); | |
372 | } | |
373 | return (1); | |
374 | } | |
375 | static EVP_CIPHER * | |
376 | evp_ssh1_3des(void) | |
377 | { | |
378 | static EVP_CIPHER ssh1_3des; | |
379 | ||
380 | memset(&ssh1_3des, 0, sizeof(EVP_CIPHER)); | |
381 | ssh1_3des.nid = NID_undef; | |
382 | ssh1_3des.block_size = 8; | |
383 | ssh1_3des.iv_len = 0; | |
384 | ssh1_3des.key_len = 16; | |
385 | ssh1_3des.init = ssh1_3des_init; | |
386 | ssh1_3des.cleanup = ssh1_3des_cleanup; | |
387 | ssh1_3des.do_cipher = ssh1_3des_cbc; | |
a068d86f | 388 | #ifndef SSH_OLD_EVP |
70fc1609 | 389 | ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH; |
a068d86f | 390 | #endif |
70fc1609 | 391 | return (&ssh1_3des); |
392 | } | |
393 | ||
394 | /* | |
395 | * SSH1 uses a variation on Blowfish, all bytes must be swapped before | |
396 | * and after encryption/decryption. Thus the swap_bytes stuff (yuk). | |
397 | */ | |
398 | static void | |
399 | swap_bytes(const u_char *src, u_char *dst, int n) | |
400 | { | |
401 | u_char c[4]; | |
402 | ||
403 | /* Process 4 bytes every lap. */ | |
404 | for (n = n / 4; n > 0; n--) { | |
405 | c[3] = *src++; | |
406 | c[2] = *src++; | |
407 | c[1] = *src++; | |
408 | c[0] = *src++; | |
409 | ||
410 | *dst++ = c[0]; | |
411 | *dst++ = c[1]; | |
412 | *dst++ = c[2]; | |
413 | *dst++ = c[3]; | |
414 | } | |
415 | } | |
416 | static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL; | |
417 | static int | |
418 | bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len) | |
419 | { | |
420 | int ret; | |
421 | ||
422 | swap_bytes(in, out, len); | |
423 | ret = (*orig_bf)(ctx, out, out, len); | |
424 | swap_bytes(out, out, len); | |
425 | return (ret); | |
426 | } | |
427 | static EVP_CIPHER * | |
428 | evp_ssh1_bf(void) | |
429 | { | |
430 | static EVP_CIPHER ssh1_bf; | |
431 | ||
432 | memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER)); | |
433 | orig_bf = ssh1_bf.do_cipher; | |
434 | ssh1_bf.nid = NID_undef; | |
435 | ssh1_bf.do_cipher = bf_ssh1_cipher; | |
436 | ssh1_bf.key_len = 32; | |
437 | return (&ssh1_bf); | |
438 | } | |
439 | ||
440 | /* RIJNDAEL */ | |
441 | #define RIJNDAEL_BLOCKSIZE 16 | |
442 | struct ssh_rijndael_ctx | |
443 | { | |
444 | rijndael_ctx r_ctx; | |
445 | u_char r_iv[RIJNDAEL_BLOCKSIZE]; | |
446 | }; | |
447 | ||
448 | static int | |
449 | ssh_rijndael_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, | |
450 | int enc) | |
451 | { | |
452 | struct ssh_rijndael_ctx *c; | |
453 | ||
454 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
455 | c = xmalloc(sizeof(*c)); | |
456 | EVP_CIPHER_CTX_set_app_data(ctx, c); | |
457 | } | |
458 | if (key != NULL) { | |
459 | if (enc == -1) | |
460 | enc = ctx->encrypt; | |
461 | rijndael_set_key(&c->r_ctx, (u_char *)key, | |
462 | 8*EVP_CIPHER_CTX_key_length(ctx), enc); | |
463 | } | |
464 | if (iv != NULL) | |
465 | memcpy(c->r_iv, iv, RIJNDAEL_BLOCKSIZE); | |
466 | return (1); | |
467 | } | |
468 | static int | |
469 | ssh_rijndael_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, | |
470 | u_int len) | |
471 | { | |
472 | struct ssh_rijndael_ctx *c; | |
473 | u_char buf[RIJNDAEL_BLOCKSIZE]; | |
474 | u_char *cprev, *cnow, *plain, *ivp; | |
475 | int i, j, blocks = len / RIJNDAEL_BLOCKSIZE; | |
476 | ||
477 | if (len == 0) | |
478 | return (1); | |
479 | if (len % RIJNDAEL_BLOCKSIZE) | |
480 | fatal("ssh_rijndael_cbc: bad len %d", len); | |
481 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
482 | error("ssh_rijndael_cbc: no context"); | |
483 | return (0); | |
484 | } | |
485 | if (ctx->encrypt) { | |
486 | cnow = dest; | |
487 | plain = (u_char *)src; | |
488 | cprev = c->r_iv; | |
489 | for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE, | |
490 | cnow+=RIJNDAEL_BLOCKSIZE) { | |
491 | for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) | |
492 | buf[j] = plain[j] ^ cprev[j]; | |
493 | rijndael_encrypt(&c->r_ctx, buf, cnow); | |
494 | cprev = cnow; | |
495 | } | |
496 | memcpy(c->r_iv, cprev, RIJNDAEL_BLOCKSIZE); | |
497 | } else { | |
498 | cnow = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE); | |
499 | plain = dest+len-RIJNDAEL_BLOCKSIZE; | |
500 | ||
501 | memcpy(buf, cnow, RIJNDAEL_BLOCKSIZE); | |
502 | for (i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE, | |
503 | plain-=RIJNDAEL_BLOCKSIZE) { | |
504 | rijndael_decrypt(&c->r_ctx, cnow, plain); | |
505 | ivp = (i == 1) ? c->r_iv : cnow-RIJNDAEL_BLOCKSIZE; | |
506 | for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) | |
507 | plain[j] ^= ivp[j]; | |
508 | } | |
509 | memcpy(c->r_iv, buf, RIJNDAEL_BLOCKSIZE); | |
510 | } | |
511 | return (1); | |
512 | } | |
513 | static int | |
514 | ssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx) | |
515 | { | |
516 | struct ssh_rijndael_ctx *c; | |
517 | ||
518 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { | |
519 | memset(c, 0, sizeof(*c)); | |
520 | xfree(c); | |
521 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); | |
522 | } | |
523 | return (1); | |
524 | } | |
525 | static EVP_CIPHER * | |
526 | evp_rijndael(void) | |
527 | { | |
528 | static EVP_CIPHER rijndal_cbc; | |
529 | ||
530 | memset(&rijndal_cbc, 0, sizeof(EVP_CIPHER)); | |
531 | rijndal_cbc.nid = NID_undef; | |
532 | rijndal_cbc.block_size = RIJNDAEL_BLOCKSIZE; | |
533 | rijndal_cbc.iv_len = RIJNDAEL_BLOCKSIZE; | |
534 | rijndal_cbc.key_len = 16; | |
535 | rijndal_cbc.init = ssh_rijndael_init; | |
536 | rijndal_cbc.cleanup = ssh_rijndael_cleanup; | |
537 | rijndal_cbc.do_cipher = ssh_rijndael_cbc; | |
a068d86f | 538 | #ifndef SSH_OLD_EVP |
70fc1609 | 539 | rijndal_cbc.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH | |
540 | EVP_CIPH_ALWAYS_CALL_INIT; | |
a068d86f | 541 | #endif |
70fc1609 | 542 | return (&rijndal_cbc); |
543 | } |