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3c0ef626 | 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" | |
bfe49944 | 38 | RCSID("$OpenBSD: cipher.c,v 1.62 2002/11/21 22:45:31 markus Exp $"); |
3c0ef626 | 39 | |
40 | #include "xmalloc.h" | |
41 | #include "log.h" | |
42 | #include "cipher.h" | |
43 | ||
44 | #include <openssl/md5.h> | |
905081a4 | 45 | |
350391c5 | 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 | ||
44a053a3 | 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); | |
905081a4 | 57 | |
58 | struct Cipher { | |
59 | char *name; | |
60 | int number; /* for ssh1 only */ | |
61 | u_int block_size; | |
62 | u_int key_len; | |
44a053a3 | 63 | const EVP_CIPHER *(*evptype)(void); |
905081a4 | 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 }, | |
44a053a3 | 74 | #if OPENSSL_VERSION_NUMBER < 0x00907000L |
905081a4 | 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 }, | |
350391c5 | 78 | { "rijndael-cbc@lysator.liu.se", |
79 | SSH_CIPHER_SSH2, 16, 32, evp_rijndael }, | |
44a053a3 | 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 | |
905081a4 | 87 | |
88 | { NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL } | |
89 | }; | |
3c0ef626 | 90 | |
905081a4 | 91 | /*--*/ |
3c0ef626 | 92 | |
905081a4 | 93 | u_int |
94 | cipher_blocksize(Cipher *c) | |
3c0ef626 | 95 | { |
905081a4 | 96 | return (c->block_size); |
3c0ef626 | 97 | } |
276b07a3 | 98 | |
905081a4 | 99 | u_int |
100 | cipher_keylen(Cipher *c) | |
3c0ef626 | 101 | { |
905081a4 | 102 | return (c->key_len); |
3c0ef626 | 103 | } |
276b07a3 | 104 | |
905081a4 | 105 | u_int |
106 | cipher_get_number(Cipher *c) | |
3c0ef626 | 107 | { |
905081a4 | 108 | return (c->number); |
3c0ef626 | 109 | } |
110 | ||
3c0ef626 | 111 | u_int |
112 | cipher_mask_ssh1(int client) | |
113 | { | |
114 | u_int mask = 0; | |
905081a4 | 115 | mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ |
3c0ef626 | 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'; | |
905081a4 | 155 | (p = strsep(&cp, CIPHER_SEP))) { |
3c0ef626 | 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, | |
905081a4 | 194 | const u_char *key, u_int keylen, const u_char *iv, u_int ivlen, |
195 | int encrypt) | |
3c0ef626 | 196 | { |
905081a4 | 197 | static int dowarn = 1; |
350391c5 | 198 | #ifdef SSH_OLD_EVP |
199 | EVP_CIPHER *type; | |
200 | #else | |
905081a4 | 201 | const EVP_CIPHER *type; |
350391c5 | 202 | #endif |
905081a4 | 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 | ||
3c0ef626 | 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; | |
905081a4 | 223 | |
224 | type = (*cipher->evptype)(); | |
225 | ||
226 | EVP_CIPHER_CTX_init(&cc->evp); | |
350391c5 | 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 | |
905081a4 | 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) { | |
bfe49944 | 242 | debug2("cipher_init: set keylen (%d -> %d)", klen, keylen); |
905081a4 | 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); | |
350391c5 | 250 | #endif |
3c0ef626 | 251 | } |
252 | ||
253 | void | |
905081a4 | 254 | cipher_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len) |
3c0ef626 | 255 | { |
256 | if (len % cc->cipher->block_size) | |
257 | fatal("cipher_encrypt: bad plaintext length %d", len); | |
350391c5 | 258 | #ifdef SSH_OLD_EVP |
259 | EVP_Cipher(&cc->evp, dest, (u_char *)src, len); | |
260 | #else | |
905081a4 | 261 | if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0) |
262 | fatal("evp_crypt: EVP_Cipher failed"); | |
350391c5 | 263 | #endif |
3c0ef626 | 264 | } |
265 | ||
266 | void | |
905081a4 | 267 | cipher_cleanup(CipherContext *cc) |
3c0ef626 | 268 | { |
350391c5 | 269 | #ifdef SSH_OLD_EVP |
270 | EVP_CIPHER_CTX_cleanup(&cc->evp); | |
271 | #else | |
905081a4 | 272 | if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0) |
273 | error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed"); | |
350391c5 | 274 | #endif |
3c0ef626 | 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, | |
905081a4 | 284 | const char *passphrase, int encrypt) |
3c0ef626 | 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 | ||
905081a4 | 293 | cipher_init(cc, cipher, digest, 16, NULL, 0, encrypt); |
3c0ef626 | 294 | |
295 | memset(digest, 0, sizeof(digest)); | |
296 | memset(&md, 0, sizeof(md)); | |
297 | } | |
905081a4 | 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 | }; | |
276b07a3 | 319 | |
905081a4 | 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); | |
350391c5 | 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 | |
905081a4 | 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 | } | |
350391c5 | 359 | #endif |
905081a4 | 360 | return (1); |
361 | } | |
276b07a3 | 362 | |
905081a4 | 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 | } | |
350391c5 | 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 | |
905081a4 | 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); | |
350391c5 | 381 | #endif |
905081a4 | 382 | return (1); |
383 | } | |
276b07a3 | 384 | |
905081a4 | 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 | } | |
276b07a3 | 397 | |
44a053a3 | 398 | static const EVP_CIPHER * |
905081a4 | 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; | |
350391c5 | 411 | #ifndef SSH_OLD_EVP |
905081a4 | 412 | ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH; |
350391c5 | 413 | #endif |
905081a4 | 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 | } | |
276b07a3 | 439 | |
d03f4262 | 440 | #ifdef SSH_OLD_EVP |
441 | static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key, | |
442 | const unsigned char *iv, int enc) | |
443 | { | |
444 | if (iv != NULL) | |
445 | memcpy (&(ctx->oiv[0]), iv, 8); | |
446 | memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8); | |
447 | if (key != NULL) | |
448 | BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx), | |
449 | key); | |
450 | } | |
451 | #endif | |
905081a4 | 452 | static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL; |
276b07a3 | 453 | |
905081a4 | 454 | static int |
455 | bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len) | |
456 | { | |
457 | int ret; | |
458 | ||
459 | swap_bytes(in, out, len); | |
460 | ret = (*orig_bf)(ctx, out, out, len); | |
461 | swap_bytes(out, out, len); | |
462 | return (ret); | |
463 | } | |
276b07a3 | 464 | |
44a053a3 | 465 | static const EVP_CIPHER * |
905081a4 | 466 | evp_ssh1_bf(void) |
467 | { | |
468 | static EVP_CIPHER ssh1_bf; | |
469 | ||
470 | memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER)); | |
471 | orig_bf = ssh1_bf.do_cipher; | |
472 | ssh1_bf.nid = NID_undef; | |
d03f4262 | 473 | #ifdef SSH_OLD_EVP |
474 | ssh1_bf.init = bf_ssh1_init; | |
475 | #endif | |
905081a4 | 476 | ssh1_bf.do_cipher = bf_ssh1_cipher; |
477 | ssh1_bf.key_len = 32; | |
478 | return (&ssh1_bf); | |
479 | } | |
480 | ||
44a053a3 | 481 | #if OPENSSL_VERSION_NUMBER < 0x00907000L |
905081a4 | 482 | /* RIJNDAEL */ |
483 | #define RIJNDAEL_BLOCKSIZE 16 | |
484 | struct ssh_rijndael_ctx | |
485 | { | |
486 | rijndael_ctx r_ctx; | |
487 | u_char r_iv[RIJNDAEL_BLOCKSIZE]; | |
488 | }; | |
489 | ||
490 | static int | |
491 | ssh_rijndael_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, | |
492 | int enc) | |
493 | { | |
494 | struct ssh_rijndael_ctx *c; | |
495 | ||
496 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
497 | c = xmalloc(sizeof(*c)); | |
498 | EVP_CIPHER_CTX_set_app_data(ctx, c); | |
499 | } | |
500 | if (key != NULL) { | |
501 | if (enc == -1) | |
502 | enc = ctx->encrypt; | |
503 | rijndael_set_key(&c->r_ctx, (u_char *)key, | |
504 | 8*EVP_CIPHER_CTX_key_length(ctx), enc); | |
505 | } | |
506 | if (iv != NULL) | |
507 | memcpy(c->r_iv, iv, RIJNDAEL_BLOCKSIZE); | |
508 | return (1); | |
509 | } | |
276b07a3 | 510 | |
905081a4 | 511 | static int |
512 | ssh_rijndael_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, | |
513 | u_int len) | |
514 | { | |
515 | struct ssh_rijndael_ctx *c; | |
516 | u_char buf[RIJNDAEL_BLOCKSIZE]; | |
517 | u_char *cprev, *cnow, *plain, *ivp; | |
518 | int i, j, blocks = len / RIJNDAEL_BLOCKSIZE; | |
519 | ||
520 | if (len == 0) | |
521 | return (1); | |
522 | if (len % RIJNDAEL_BLOCKSIZE) | |
523 | fatal("ssh_rijndael_cbc: bad len %d", len); | |
524 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { | |
525 | error("ssh_rijndael_cbc: no context"); | |
526 | return (0); | |
527 | } | |
528 | if (ctx->encrypt) { | |
529 | cnow = dest; | |
530 | plain = (u_char *)src; | |
531 | cprev = c->r_iv; | |
532 | for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE, | |
533 | cnow+=RIJNDAEL_BLOCKSIZE) { | |
534 | for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) | |
535 | buf[j] = plain[j] ^ cprev[j]; | |
536 | rijndael_encrypt(&c->r_ctx, buf, cnow); | |
537 | cprev = cnow; | |
538 | } | |
539 | memcpy(c->r_iv, cprev, RIJNDAEL_BLOCKSIZE); | |
540 | } else { | |
541 | cnow = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE); | |
542 | plain = dest+len-RIJNDAEL_BLOCKSIZE; | |
543 | ||
544 | memcpy(buf, cnow, RIJNDAEL_BLOCKSIZE); | |
545 | for (i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE, | |
546 | plain-=RIJNDAEL_BLOCKSIZE) { | |
547 | rijndael_decrypt(&c->r_ctx, cnow, plain); | |
548 | ivp = (i == 1) ? c->r_iv : cnow-RIJNDAEL_BLOCKSIZE; | |
549 | for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) | |
550 | plain[j] ^= ivp[j]; | |
551 | } | |
552 | memcpy(c->r_iv, buf, RIJNDAEL_BLOCKSIZE); | |
553 | } | |
554 | return (1); | |
555 | } | |
276b07a3 | 556 | |
905081a4 | 557 | static int |
558 | ssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx) | |
559 | { | |
560 | struct ssh_rijndael_ctx *c; | |
561 | ||
562 | if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { | |
563 | memset(c, 0, sizeof(*c)); | |
564 | xfree(c); | |
565 | EVP_CIPHER_CTX_set_app_data(ctx, NULL); | |
566 | } | |
567 | return (1); | |
568 | } | |
276b07a3 | 569 | |
44a053a3 | 570 | static const EVP_CIPHER * |
905081a4 | 571 | evp_rijndael(void) |
572 | { | |
573 | static EVP_CIPHER rijndal_cbc; | |
574 | ||
575 | memset(&rijndal_cbc, 0, sizeof(EVP_CIPHER)); | |
576 | rijndal_cbc.nid = NID_undef; | |
577 | rijndal_cbc.block_size = RIJNDAEL_BLOCKSIZE; | |
578 | rijndal_cbc.iv_len = RIJNDAEL_BLOCKSIZE; | |
579 | rijndal_cbc.key_len = 16; | |
580 | rijndal_cbc.init = ssh_rijndael_init; | |
581 | rijndal_cbc.cleanup = ssh_rijndael_cleanup; | |
582 | rijndal_cbc.do_cipher = ssh_rijndael_cbc; | |
350391c5 | 583 | #ifndef SSH_OLD_EVP |
905081a4 | 584 | rijndal_cbc.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH | |
d03f4262 | 585 | EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CUSTOM_IV; |
350391c5 | 586 | #endif |
905081a4 | 587 | return (&rijndal_cbc); |
588 | } | |
44a053a3 | 589 | #endif |
905081a4 | 590 | |
591 | /* | |
592 | * Exports an IV from the CipherContext required to export the key | |
593 | * state back from the unprivileged child to the privileged parent | |
594 | * process. | |
595 | */ | |
596 | ||
597 | int | |
598 | cipher_get_keyiv_len(CipherContext *cc) | |
599 | { | |
600 | Cipher *c = cc->cipher; | |
601 | int ivlen; | |
602 | ||
603 | if (c->number == SSH_CIPHER_3DES) | |
604 | ivlen = 24; | |
605 | else | |
606 | ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp); | |
607 | return (ivlen); | |
608 | } | |
609 | ||
610 | void | |
611 | cipher_get_keyiv(CipherContext *cc, u_char *iv, u_int len) | |
612 | { | |
613 | Cipher *c = cc->cipher; | |
614 | u_char *civ = NULL; | |
615 | int evplen; | |
616 | ||
617 | switch (c->number) { | |
618 | case SSH_CIPHER_SSH2: | |
619 | case SSH_CIPHER_DES: | |
620 | case SSH_CIPHER_BLOWFISH: | |
621 | evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); | |
622 | if (evplen == 0) | |
623 | return; | |
624 | if (evplen != len) | |
44a053a3 | 625 | fatal("%s: wrong iv length %d != %d", __func__, |
905081a4 | 626 | evplen, len); |
627 | ||
44a053a3 | 628 | #if OPENSSL_VERSION_NUMBER < 0x00907000L |
350391c5 | 629 | if (c->evptype == evp_rijndael) { |
905081a4 | 630 | struct ssh_rijndael_ctx *aesc; |
631 | ||
632 | aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
633 | if (aesc == NULL) | |
44a053a3 | 634 | fatal("%s: no rijndael context", __func__); |
905081a4 | 635 | civ = aesc->r_iv; |
44a053a3 | 636 | } else |
637 | #endif | |
638 | { | |
905081a4 | 639 | civ = cc->evp.iv; |
640 | } | |
641 | break; | |
642 | case SSH_CIPHER_3DES: { | |
643 | struct ssh1_3des_ctx *desc; | |
644 | if (len != 24) | |
44a053a3 | 645 | fatal("%s: bad 3des iv length: %d", __func__, len); |
905081a4 | 646 | desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); |
647 | if (desc == NULL) | |
44a053a3 | 648 | fatal("%s: no 3des context", __func__); |
649 | debug3("%s: Copying 3DES IV", __func__); | |
905081a4 | 650 | memcpy(iv, desc->k1.iv, 8); |
651 | memcpy(iv + 8, desc->k2.iv, 8); | |
652 | memcpy(iv + 16, desc->k3.iv, 8); | |
653 | return; | |
654 | } | |
655 | default: | |
44a053a3 | 656 | fatal("%s: bad cipher %d", __func__, c->number); |
905081a4 | 657 | } |
658 | memcpy(iv, civ, len); | |
659 | } | |
660 | ||
661 | void | |
662 | cipher_set_keyiv(CipherContext *cc, u_char *iv) | |
663 | { | |
664 | Cipher *c = cc->cipher; | |
665 | u_char *div = NULL; | |
666 | int evplen = 0; | |
667 | ||
668 | switch (c->number) { | |
669 | case SSH_CIPHER_SSH2: | |
670 | case SSH_CIPHER_DES: | |
671 | case SSH_CIPHER_BLOWFISH: | |
672 | evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); | |
673 | if (evplen == 0) | |
674 | return; | |
675 | ||
44a053a3 | 676 | #if OPENSSL_VERSION_NUMBER < 0x00907000L |
350391c5 | 677 | if (c->evptype == evp_rijndael) { |
905081a4 | 678 | struct ssh_rijndael_ctx *aesc; |
679 | ||
680 | aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
681 | if (aesc == NULL) | |
44a053a3 | 682 | fatal("%s: no rijndael context", __func__); |
905081a4 | 683 | div = aesc->r_iv; |
44a053a3 | 684 | } else |
685 | #endif | |
686 | { | |
905081a4 | 687 | div = cc->evp.iv; |
688 | } | |
689 | break; | |
690 | case SSH_CIPHER_3DES: { | |
691 | struct ssh1_3des_ctx *desc; | |
692 | desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); | |
693 | if (desc == NULL) | |
44a053a3 | 694 | fatal("%s: no 3des context", __func__); |
695 | debug3("%s: Installed 3DES IV", __func__); | |
905081a4 | 696 | memcpy(desc->k1.iv, iv, 8); |
697 | memcpy(desc->k2.iv, iv + 8, 8); | |
698 | memcpy(desc->k3.iv, iv + 16, 8); | |
699 | return; | |
700 | } | |
701 | default: | |
44a053a3 | 702 | fatal("%s: bad cipher %d", __func__, c->number); |
905081a4 | 703 | } |
704 | memcpy(div, iv, evplen); | |
705 | } | |
706 | ||
707 | #if OPENSSL_VERSION_NUMBER < 0x00907000L | |
708 | #define EVP_X_STATE(evp) &(evp).c | |
709 | #define EVP_X_STATE_LEN(evp) sizeof((evp).c) | |
710 | #else | |
711 | #define EVP_X_STATE(evp) (evp).cipher_data | |
712 | #define EVP_X_STATE_LEN(evp) (evp).cipher->ctx_size | |
713 | #endif | |
714 | ||
715 | int | |
716 | cipher_get_keycontext(CipherContext *cc, u_char *dat) | |
717 | { | |
718 | Cipher *c = cc->cipher; | |
44a053a3 | 719 | int plen = 0; |
905081a4 | 720 | |
44a053a3 | 721 | if (c->evptype == EVP_rc4) { |
722 | plen = EVP_X_STATE_LEN(cc->evp); | |
905081a4 | 723 | if (dat == NULL) |
44a053a3 | 724 | return (plen); |
725 | memcpy(dat, EVP_X_STATE(cc->evp), plen); | |
905081a4 | 726 | } |
905081a4 | 727 | return (plen); |
728 | } | |
729 | ||
730 | void | |
731 | cipher_set_keycontext(CipherContext *cc, u_char *dat) | |
732 | { | |
733 | Cipher *c = cc->cipher; | |
734 | int plen; | |
735 | ||
44a053a3 | 736 | if (c->evptype == EVP_rc4) { |
905081a4 | 737 | plen = EVP_X_STATE_LEN(cc->evp); |
738 | memcpy(EVP_X_STATE(cc->evp), dat, plen); | |
739 | } | |
740 | } |