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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" | |
762715ce | 38 | RCSID("$OpenBSD: cipher.c,v 1.54 2002/03/19 10:49:35 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 | ||
762715ce | 81 | u_int |
3ee832e5 | 82 | cipher_blocksize(Cipher *c) |
83 | { | |
84 | return (c->block_size); | |
85 | } | |
762715ce | 86 | u_int |
3ee832e5 | 87 | cipher_keylen(Cipher *c) |
88 | { | |
89 | return (c->key_len); | |
90 | } | |
762715ce | 91 | u_int |
bf8269a9 | 92 | cipher_get_number(Cipher *c) |
93 | { | |
94 | return (c->number); | |
95 | } | |
3ee832e5 | 96 | |
1e3b8b07 | 97 | u_int |
94ec8c6b | 98 | cipher_mask_ssh1(int client) |
8ce64345 | 99 | { |
1e3b8b07 | 100 | u_int mask = 0; |
184eed6a | 101 | mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ |
94ec8c6b | 102 | mask |= 1 << SSH_CIPHER_BLOWFISH; |
103 | if (client) { | |
104 | mask |= 1 << SSH_CIPHER_DES; | |
105 | } | |
5260325f | 106 | return mask; |
8efc0c15 | 107 | } |
94ec8c6b | 108 | |
109 | Cipher * | |
110 | cipher_by_name(const char *name) | |
8ce64345 | 111 | { |
94ec8c6b | 112 | Cipher *c; |
113 | for (c = ciphers; c->name != NULL; c++) | |
114 | if (strcasecmp(c->name, name) == 0) | |
115 | return c; | |
116 | return NULL; | |
8ce64345 | 117 | } |
8efc0c15 | 118 | |
94ec8c6b | 119 | Cipher * |
120 | cipher_by_number(int id) | |
8efc0c15 | 121 | { |
94ec8c6b | 122 | Cipher *c; |
123 | for (c = ciphers; c->name != NULL; c++) | |
124 | if (c->number == id) | |
125 | return c; | |
126 | return NULL; | |
8efc0c15 | 127 | } |
128 | ||
a8be9f80 | 129 | #define CIPHER_SEP "," |
130 | int | |
131 | ciphers_valid(const char *names) | |
132 | { | |
94ec8c6b | 133 | Cipher *c; |
089fbbd2 | 134 | char *ciphers, *cp; |
a8be9f80 | 135 | char *p; |
a8be9f80 | 136 | |
71276795 | 137 | if (names == NULL || strcmp(names, "") == 0) |
a8be9f80 | 138 | return 0; |
089fbbd2 | 139 | ciphers = cp = xstrdup(names); |
94ec8c6b | 140 | for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0'; |
184eed6a | 141 | (p = strsep(&cp, CIPHER_SEP))) { |
94ec8c6b | 142 | c = cipher_by_name(p); |
143 | if (c == NULL || c->number != SSH_CIPHER_SSH2) { | |
144 | debug("bad cipher %s [%s]", p, names); | |
a8be9f80 | 145 | xfree(ciphers); |
146 | return 0; | |
94ec8c6b | 147 | } else { |
33de75a3 | 148 | debug3("cipher ok: %s [%s]", p, names); |
a8be9f80 | 149 | } |
150 | } | |
33de75a3 | 151 | debug3("ciphers ok: [%s]", names); |
a8be9f80 | 152 | xfree(ciphers); |
153 | return 1; | |
154 | } | |
155 | ||
aa3378df | 156 | /* |
157 | * Parses the name of the cipher. Returns the number of the corresponding | |
158 | * cipher, or -1 on error. | |
159 | */ | |
8efc0c15 | 160 | |
161 | int | |
162 | cipher_number(const char *name) | |
163 | { | |
94ec8c6b | 164 | Cipher *c; |
71276795 | 165 | if (name == NULL) |
166 | return -1; | |
94ec8c6b | 167 | c = cipher_by_name(name); |
168 | return (c==NULL) ? -1 : c->number; | |
169 | } | |
170 | ||
171 | char * | |
172 | cipher_name(int id) | |
173 | { | |
174 | Cipher *c = cipher_by_number(id); | |
175 | return (c==NULL) ? "<unknown>" : c->name; | |
176 | } | |
177 | ||
178 | void | |
70fc1609 | 179 | cipher_init(CipherContext *cc, Cipher *cipher, |
180 | const u_char *key, u_int keylen, const u_char *iv, u_int ivlen, | |
181 | int encrypt) | |
94ec8c6b | 182 | { |
70fc1609 | 183 | static int dowarn = 1; |
a068d86f | 184 | #ifdef SSH_OLD_EVP |
185 | EVP_CIPHER *type; | |
186 | #else | |
70fc1609 | 187 | const EVP_CIPHER *type; |
a068d86f | 188 | #endif |
70fc1609 | 189 | int klen; |
190 | ||
191 | if (cipher->number == SSH_CIPHER_DES) { | |
192 | if (dowarn) { | |
193 | error("Warning: use of DES is strongly discouraged " | |
194 | "due to cryptographic weaknesses"); | |
195 | dowarn = 0; | |
196 | } | |
197 | if (keylen > 8) | |
198 | keylen = 8; | |
199 | } | |
200 | cc->plaintext = (cipher->number == SSH_CIPHER_NONE); | |
201 | ||
94ec8c6b | 202 | if (keylen < cipher->key_len) |
203 | fatal("cipher_init: key length %d is insufficient for %s.", | |
204 | keylen, cipher->name); | |
205 | if (iv != NULL && ivlen < cipher->block_size) | |
206 | fatal("cipher_init: iv length %d is insufficient for %s.", | |
207 | ivlen, cipher->name); | |
208 | cc->cipher = cipher; | |
70fc1609 | 209 | |
210 | type = (*cipher->evptype)(); | |
211 | ||
212 | EVP_CIPHER_CTX_init(&cc->evp); | |
a068d86f | 213 | #ifdef SSH_OLD_EVP |
214 | if (type->key_len > 0 && type->key_len != keylen) { | |
215 | debug("cipher_init: set keylen (%d -> %d)", | |
216 | type->key_len, keylen); | |
217 | type->key_len = keylen; | |
218 | } | |
219 | EVP_CipherInit(&cc->evp, type, (u_char *)key, (u_char *)iv, | |
220 | (encrypt == CIPHER_ENCRYPT)); | |
221 | #else | |
70fc1609 | 222 | if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv, |
223 | (encrypt == CIPHER_ENCRYPT)) == 0) | |
224 | fatal("cipher_init: EVP_CipherInit failed for %s", | |
225 | cipher->name); | |
226 | klen = EVP_CIPHER_CTX_key_length(&cc->evp); | |
227 | if (klen > 0 && keylen != klen) { | |
228 | debug("cipher_init: set keylen (%d -> %d)", klen, keylen); | |
229 | if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0) | |
230 | fatal("cipher_init: set keylen failed (%d -> %d)", | |
231 | klen, keylen); | |
232 | } | |
233 | if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0) | |
234 | fatal("cipher_init: EVP_CipherInit: set key failed for %s", | |
235 | cipher->name); | |
a068d86f | 236 | #endif |
94ec8c6b | 237 | } |
238 | ||
239 | void | |
3ee832e5 | 240 | cipher_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len) |
94ec8c6b | 241 | { |
242 | if (len % cc->cipher->block_size) | |
243 | fatal("cipher_encrypt: bad plaintext length %d", len); | |
a068d86f | 244 | #ifdef SSH_OLD_EVP |
245 | EVP_Cipher(&cc->evp, dest, (u_char *)src, len); | |
246 | #else | |
70fc1609 | 247 | if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0) |
248 | fatal("evp_crypt: EVP_Cipher failed"); | |
a068d86f | 249 | #endif |
94ec8c6b | 250 | } |
251 | ||
252 | void | |
3ee832e5 | 253 | cipher_cleanup(CipherContext *cc) |
94ec8c6b | 254 | { |
a068d86f | 255 | #ifdef SSH_OLD_EVP |
256 | EVP_CIPHER_CTX_cleanup(&cc->evp); | |
257 | #else | |
70fc1609 | 258 | if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0) |
259 | error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed"); | |
a068d86f | 260 | #endif |
8efc0c15 | 261 | } |
262 | ||
aa3378df | 263 | /* |
264 | * Selects the cipher, and keys if by computing the MD5 checksum of the | |
265 | * passphrase and using the resulting 16 bytes as the key. | |
266 | */ | |
8efc0c15 | 267 | |
6ae2364d | 268 | void |
94ec8c6b | 269 | cipher_set_key_string(CipherContext *cc, Cipher *cipher, |
3ee832e5 | 270 | const char *passphrase, int encrypt) |
8efc0c15 | 271 | { |
5260325f | 272 | MD5_CTX md; |
1e3b8b07 | 273 | u_char digest[16]; |
5260325f | 274 | |
275 | MD5_Init(&md); | |
94ec8c6b | 276 | MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase)); |
5260325f | 277 | MD5_Final(digest, &md); |
278 | ||
3ee832e5 | 279 | cipher_init(cc, cipher, digest, 16, NULL, 0, encrypt); |
5260325f | 280 | |
281 | memset(digest, 0, sizeof(digest)); | |
282 | memset(&md, 0, sizeof(md)); | |
8efc0c15 | 283 | } |
70fc1609 | 284 | |
285 | /* Implementations for other non-EVP ciphers */ | |
286 | ||
287 | /* | |
288 | * This is used by SSH1: | |
289 | * | |
290 | * What kind of triple DES are these 2 routines? | |
291 | * | |
292 | * Why is there a redundant initialization vector? | |
293 | * | |
294 | * If only iv3 was used, then, this would till effect have been | |
295 | * outer-cbc. However, there is also a private iv1 == iv2 which | |
296 | * perhaps makes differential analysis easier. On the other hand, the | |
297 | * private iv1 probably makes the CRC-32 attack ineffective. This is a | |
298 | * result of that there is no longer any known iv1 to use when | |
299 | * choosing the X block. | |
300 | */ | |
301 | struct ssh1_3des_ctx | |
302 | { | |
303 | EVP_CIPHER_CTX k1, k2, k3; | |
304 | }; | |
305 | static int | |
306 | ssh1_3des_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, | |
307 | int enc) | |
308 | { | |
309 | struct ssh1_3des_ctx *c; | |
310 | u_char *k1, *k2, *k3; | |
311 | ||
312 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
313 | c = xmalloc(sizeof(*c)); | |
314 | EVP_CIPHER_CTX_set_app_data(ctx, c); | |
315 | } | |
316 | if (key == NULL) | |
317 | return (1); | |
318 | if (enc == -1) | |
319 | enc = ctx->encrypt; | |
320 | k1 = k2 = k3 = (u_char *) key; | |
321 | k2 += 8; | |
322 | if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) { | |
323 | if (enc) | |
324 | k3 += 16; | |
325 | else | |
326 | k1 += 16; | |
327 | } | |
328 | EVP_CIPHER_CTX_init(&c->k1); | |
329 | EVP_CIPHER_CTX_init(&c->k2); | |
330 | EVP_CIPHER_CTX_init(&c->k3); | |
a068d86f | 331 | #ifdef SSH_OLD_EVP |
332 | EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc); | |
333 | EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc); | |
334 | EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc); | |
335 | #else | |
70fc1609 | 336 | if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 || |
337 | EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 || | |
338 | EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) { | |
339 | memset(c, 0, sizeof(*c)); | |
340 | xfree(c); | |
341 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); | |
342 | return (0); | |
343 | } | |
a068d86f | 344 | #endif |
70fc1609 | 345 | return (1); |
346 | } | |
347 | static int | |
348 | ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, u_int len) | |
349 | { | |
350 | struct ssh1_3des_ctx *c; | |
351 | ||
352 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
353 | error("ssh1_3des_cbc: no context"); | |
354 | return (0); | |
355 | } | |
a068d86f | 356 | #ifdef SSH_OLD_EVP |
357 | EVP_Cipher(&c->k1, dest, (u_char *)src, len); | |
358 | EVP_Cipher(&c->k2, dest, dest, len); | |
359 | EVP_Cipher(&c->k3, dest, dest, len); | |
360 | #else | |
70fc1609 | 361 | if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 || |
362 | EVP_Cipher(&c->k2, dest, dest, len) == 0 || | |
363 | EVP_Cipher(&c->k3, dest, dest, len) == 0) | |
364 | return (0); | |
a068d86f | 365 | #endif |
70fc1609 | 366 | return (1); |
367 | } | |
368 | static int | |
369 | ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx) | |
370 | { | |
371 | struct ssh1_3des_ctx *c; | |
372 | ||
373 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { | |
374 | memset(c, 0, sizeof(*c)); | |
375 | xfree(c); | |
376 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); | |
377 | } | |
378 | return (1); | |
379 | } | |
380 | static EVP_CIPHER * | |
381 | evp_ssh1_3des(void) | |
382 | { | |
383 | static EVP_CIPHER ssh1_3des; | |
384 | ||
385 | memset(&ssh1_3des, 0, sizeof(EVP_CIPHER)); | |
386 | ssh1_3des.nid = NID_undef; | |
387 | ssh1_3des.block_size = 8; | |
388 | ssh1_3des.iv_len = 0; | |
389 | ssh1_3des.key_len = 16; | |
390 | ssh1_3des.init = ssh1_3des_init; | |
391 | ssh1_3des.cleanup = ssh1_3des_cleanup; | |
392 | ssh1_3des.do_cipher = ssh1_3des_cbc; | |
a068d86f | 393 | #ifndef SSH_OLD_EVP |
70fc1609 | 394 | ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH; |
a068d86f | 395 | #endif |
70fc1609 | 396 | return (&ssh1_3des); |
397 | } | |
398 | ||
399 | /* | |
400 | * SSH1 uses a variation on Blowfish, all bytes must be swapped before | |
401 | * and after encryption/decryption. Thus the swap_bytes stuff (yuk). | |
402 | */ | |
403 | static void | |
404 | swap_bytes(const u_char *src, u_char *dst, int n) | |
405 | { | |
406 | u_char c[4]; | |
407 | ||
408 | /* Process 4 bytes every lap. */ | |
409 | for (n = n / 4; n > 0; n--) { | |
410 | c[3] = *src++; | |
411 | c[2] = *src++; | |
412 | c[1] = *src++; | |
413 | c[0] = *src++; | |
414 | ||
415 | *dst++ = c[0]; | |
416 | *dst++ = c[1]; | |
417 | *dst++ = c[2]; | |
418 | *dst++ = c[3]; | |
419 | } | |
420 | } | |
421 | static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL; | |
422 | static int | |
423 | bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len) | |
424 | { | |
425 | int ret; | |
426 | ||
427 | swap_bytes(in, out, len); | |
428 | ret = (*orig_bf)(ctx, out, out, len); | |
429 | swap_bytes(out, out, len); | |
430 | return (ret); | |
431 | } | |
432 | static EVP_CIPHER * | |
433 | evp_ssh1_bf(void) | |
434 | { | |
435 | static EVP_CIPHER ssh1_bf; | |
436 | ||
437 | memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER)); | |
438 | orig_bf = ssh1_bf.do_cipher; | |
439 | ssh1_bf.nid = NID_undef; | |
440 | ssh1_bf.do_cipher = bf_ssh1_cipher; | |
441 | ssh1_bf.key_len = 32; | |
442 | return (&ssh1_bf); | |
443 | } | |
444 | ||
445 | /* RIJNDAEL */ | |
446 | #define RIJNDAEL_BLOCKSIZE 16 | |
447 | struct ssh_rijndael_ctx | |
448 | { | |
449 | rijndael_ctx r_ctx; | |
450 | u_char r_iv[RIJNDAEL_BLOCKSIZE]; | |
451 | }; | |
452 | ||
453 | static int | |
454 | ssh_rijndael_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, | |
455 | int enc) | |
456 | { | |
457 | struct ssh_rijndael_ctx *c; | |
458 | ||
459 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
460 | c = xmalloc(sizeof(*c)); | |
461 | EVP_CIPHER_CTX_set_app_data(ctx, c); | |
462 | } | |
463 | if (key != NULL) { | |
464 | if (enc == -1) | |
465 | enc = ctx->encrypt; | |
466 | rijndael_set_key(&c->r_ctx, (u_char *)key, | |
467 | 8*EVP_CIPHER_CTX_key_length(ctx), enc); | |
468 | } | |
469 | if (iv != NULL) | |
470 | memcpy(c->r_iv, iv, RIJNDAEL_BLOCKSIZE); | |
471 | return (1); | |
472 | } | |
473 | static int | |
474 | ssh_rijndael_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, | |
475 | u_int len) | |
476 | { | |
477 | struct ssh_rijndael_ctx *c; | |
478 | u_char buf[RIJNDAEL_BLOCKSIZE]; | |
479 | u_char *cprev, *cnow, *plain, *ivp; | |
480 | int i, j, blocks = len / RIJNDAEL_BLOCKSIZE; | |
481 | ||
482 | if (len == 0) | |
483 | return (1); | |
484 | if (len % RIJNDAEL_BLOCKSIZE) | |
485 | fatal("ssh_rijndael_cbc: bad len %d", len); | |
486 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
487 | error("ssh_rijndael_cbc: no context"); | |
488 | return (0); | |
489 | } | |
490 | if (ctx->encrypt) { | |
491 | cnow = dest; | |
492 | plain = (u_char *)src; | |
493 | cprev = c->r_iv; | |
494 | for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE, | |
495 | cnow+=RIJNDAEL_BLOCKSIZE) { | |
496 | for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) | |
497 | buf[j] = plain[j] ^ cprev[j]; | |
498 | rijndael_encrypt(&c->r_ctx, buf, cnow); | |
499 | cprev = cnow; | |
500 | } | |
501 | memcpy(c->r_iv, cprev, RIJNDAEL_BLOCKSIZE); | |
502 | } else { | |
503 | cnow = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE); | |
504 | plain = dest+len-RIJNDAEL_BLOCKSIZE; | |
505 | ||
506 | memcpy(buf, cnow, RIJNDAEL_BLOCKSIZE); | |
507 | for (i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE, | |
508 | plain-=RIJNDAEL_BLOCKSIZE) { | |
509 | rijndael_decrypt(&c->r_ctx, cnow, plain); | |
05976246 | 510 | ivp = (i == 1) ? c->r_iv : cnow-RIJNDAEL_BLOCKSIZE; |
511 | for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) | |
512 | plain[j] ^= ivp[j]; | |
513 | } | |
514 | memcpy(c->r_iv, buf, RIJNDAEL_BLOCKSIZE); | |
515 | } | |
516 | return (1); | |
517 | } | |
518 | static int | |
519 | ssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx) | |
520 | { | |
521 | struct ssh_rijndael_ctx *c; | |
522 | ||
523 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { | |
524 | memset(c, 0, sizeof(*c)); | |
525 | xfree(c); | |
526 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); | |
527 | } | |
528 | return (1); | |
529 | } | |
530 | static EVP_CIPHER * | |
531 | evp_rijndael(void) | |
532 | { | |
533 | static EVP_CIPHER rijndal_cbc; | |
534 | ||
535 | memset(&rijndal_cbc, 0, sizeof(EVP_CIPHER)); | |
536 | rijndal_cbc.nid = NID_undef; | |
537 | rijndal_cbc.block_size = RIJNDAEL_BLOCKSIZE; | |
538 | rijndal_cbc.iv_len = RIJNDAEL_BLOCKSIZE; | |
539 | rijndal_cbc.key_len = 16; | |
540 | rijndal_cbc.init = ssh_rijndael_init; | |
541 | rijndal_cbc.cleanup = ssh_rijndael_cleanup; | |
542 | rijndal_cbc.do_cipher = ssh_rijndael_cbc; | |
543 | #ifndef SSH_OLD_EVP | |
544 | rijndal_cbc.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH | | |
545 | EVP_CIPH_ALWAYS_CALL_INIT; | |
546 | #endif | |
547 | return (&rijndal_cbc); | |
bf8269a9 | 548 | } |
549 | ||
762715ce | 550 | /* |
bf8269a9 | 551 | * Exports an IV from the CipherContext required to export the key |
552 | * state back from the unprivileged child to the privileged parent | |
553 | * process. | |
554 | */ | |
555 | ||
556 | int | |
557 | cipher_get_keyiv_len(CipherContext *cc) | |
558 | { | |
559 | Cipher *c = cc->cipher; | |
560 | int ivlen; | |
561 | ||
562 | if (c->number == SSH_CIPHER_3DES) | |
563 | ivlen = 24; | |
564 | else | |
565 | ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp); | |
566 | return (ivlen); | |
567 | } | |
568 | ||
569 | void | |
570 | cipher_get_keyiv(CipherContext *cc, u_char *iv, u_int len) | |
571 | { | |
572 | Cipher *c = cc->cipher; | |
573 | u_char *civ = NULL; | |
574 | int evplen; | |
575 | ||
576 | switch (c->number) { | |
577 | case SSH_CIPHER_SSH2: | |
578 | case SSH_CIPHER_DES: | |
579 | case SSH_CIPHER_BLOWFISH: | |
580 | evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); | |
581 | if (evplen == 0) | |
582 | return; | |
583 | if (evplen != len) | |
584 | fatal("%s: wrong iv length %d != %d", __FUNCTION__, | |
585 | evplen, len); | |
586 | ||
587 | if (strncmp(c->name, "aes", 3) == 0) { | |
588 | struct ssh_rijndael_ctx *aesc; | |
589 | ||
590 | aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
591 | if (aesc == NULL) | |
592 | fatal("%s: no rijndael context", __FUNCTION__); | |
593 | civ = aesc->r_iv; | |
594 | } else { | |
595 | civ = cc->evp.iv; | |
596 | } | |
597 | break; | |
598 | case SSH_CIPHER_3DES: { | |
599 | struct ssh1_3des_ctx *desc; | |
600 | if (len != 24) | |
601 | fatal("%s: bad 3des iv length: %d", __FUNCTION__, len); | |
602 | desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
603 | if (desc == NULL) | |
604 | fatal("%s: no 3des context", __FUNCTION__); | |
605 | debug3("%s: Copying 3DES IV", __FUNCTION__); | |
606 | memcpy(iv, desc->k1.iv, 8); | |
607 | memcpy(iv + 8, desc->k2.iv, 8); | |
608 | memcpy(iv + 16, desc->k3.iv, 8); | |
609 | return; | |
610 | } | |
611 | default: | |
612 | fatal("%s: bad cipher %d", __FUNCTION__, c->number); | |
613 | } | |
614 | memcpy(iv, civ, len); | |
615 | } | |
616 | ||
617 | void | |
618 | cipher_set_keyiv(CipherContext *cc, u_char *iv) | |
619 | { | |
620 | Cipher *c = cc->cipher; | |
621 | u_char *div = NULL; | |
622 | int evplen = 0; | |
623 | ||
624 | switch (c->number) { | |
625 | case SSH_CIPHER_SSH2: | |
626 | case SSH_CIPHER_DES: | |
627 | case SSH_CIPHER_BLOWFISH: | |
628 | evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); | |
629 | if (evplen == 0) | |
630 | return; | |
631 | ||
632 | if (strncmp(c->name, "aes", 3) == 0) { | |
633 | struct ssh_rijndael_ctx *aesc; | |
634 | ||
635 | aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
636 | if (aesc == NULL) | |
637 | fatal("%s: no rijndael context", __FUNCTION__); | |
638 | div = aesc->r_iv; | |
639 | }else { | |
640 | div = cc->evp.iv; | |
641 | } | |
642 | break; | |
643 | case SSH_CIPHER_3DES: { | |
644 | struct ssh1_3des_ctx *desc; | |
645 | desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
646 | if (desc == NULL) | |
647 | fatal("%s: no 3des context", __FUNCTION__); | |
648 | debug3("%s: Installed 3DES IV", __FUNCTION__); | |
649 | memcpy(desc->k1.iv, iv, 8); | |
650 | memcpy(desc->k2.iv, iv + 8, 8); | |
651 | memcpy(desc->k3.iv, iv + 16, 8); | |
652 | return; | |
762715ce | 653 | } |
bf8269a9 | 654 | default: |
655 | fatal("%s: bad cipher %d", __FUNCTION__, c->number); | |
656 | } | |
657 | memcpy(div, iv, evplen); | |
658 | } | |
659 | ||
660 | #if OPENSSL_VERSION_NUMBER < 0x00907000L | |
661 | #define EVP_X_STATE(evp) &(evp).c | |
662 | #define EVP_X_STATE_LEN(evp) sizeof((evp).c) | |
663 | #else | |
664 | #define EVP_X_STATE(evp) (evp).cipher_data | |
665 | #define EVP_X_STATE_LEN(evp) (evp).cipher->ctx_size | |
666 | #endif | |
667 | ||
668 | int | |
669 | cipher_get_keycontext(CipherContext *cc, u_char *dat) | |
670 | { | |
671 | Cipher *c = cc->cipher; | |
672 | int plen; | |
673 | ||
674 | if (c->number == SSH_CIPHER_3DES) { | |
675 | struct ssh1_3des_ctx *desc; | |
676 | desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
677 | if (desc == NULL) | |
678 | fatal("%s: no 3des context", __FUNCTION__); | |
679 | plen = EVP_X_STATE_LEN(desc->k1); | |
680 | if (dat == NULL) | |
681 | return (3*plen); | |
682 | memcpy(dat, EVP_X_STATE(desc->k1), plen); | |
683 | memcpy(dat + plen, EVP_X_STATE(desc->k2), plen); | |
684 | memcpy(dat + 2*plen, EVP_X_STATE(desc->k3), plen); | |
685 | return (3*plen); | |
686 | } | |
687 | ||
688 | /* Generic EVP */ | |
689 | plen = EVP_X_STATE_LEN(cc->evp); | |
690 | if (dat == NULL) | |
691 | return (plen); | |
692 | ||
693 | memcpy(dat, EVP_X_STATE(cc->evp), plen); | |
694 | return (plen); | |
695 | } | |
696 | ||
697 | void | |
698 | cipher_set_keycontext(CipherContext *cc, u_char *dat) | |
699 | { | |
700 | Cipher *c = cc->cipher; | |
701 | int plen; | |
702 | ||
703 | if (c->number == SSH_CIPHER_3DES) { | |
704 | struct ssh1_3des_ctx *desc; | |
705 | desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
706 | if (desc == NULL) | |
707 | fatal("%s: no 3des context", __FUNCTION__); | |
708 | plen = EVP_X_STATE_LEN(desc->k1); | |
709 | memcpy(EVP_X_STATE(desc->k1), dat, plen); | |
710 | memcpy(EVP_X_STATE(desc->k2), dat + plen, plen); | |
711 | memcpy(EVP_X_STATE(desc->k3), dat + 2*plen, plen); | |
712 | } else { | |
713 | plen = EVP_X_STATE_LEN(cc->evp); | |
714 | memcpy(EVP_X_STATE(cc->evp), dat, plen); | |
715 | } | |
70fc1609 | 716 | } |