1 /* $OpenBSD: cipher.c,v 1.101 2015/12/10 17:08:40 mmcc Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * 7 * As far as I am concerned, the code I have written for this software 8 * can be used freely for any purpose. Any derived versions of this 9 * software must be clearly marked as such, and if the derived work is 10 * incompatible with the protocol description in the RFC file, it must be 11 * called by a name other than "ssh" or "Secure Shell". 12 * 13 * 14 * Copyright (c) 1999 Niels Provos. All rights reserved. 15 * Copyright (c) 1999, 2000 Markus Friedl. All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions 19 * are met: 20 * 1. Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 2. Redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 #include <sys/types.h> 39 40 #include <string.h> 41 #include <stdarg.h> 42 #include <stdio.h> 43 44 #include "cipher.h" 45 #include "misc.h" 46 #include "sshbuf.h" 47 #include "ssherr.h" 48 #include "digest.h" 49 50 #ifdef WITH_SSH1 51 extern const EVP_CIPHER *evp_ssh1_bf(void); 52 extern const EVP_CIPHER *evp_ssh1_3des(void); 53 extern int ssh1_3des_iv(EVP_CIPHER_CTX *, int, u_char *, int); 54 #endif 55 56 struct sshcipher { 57 char *name; 58 int number; /* for ssh1 only */ 59 u_int block_size; 60 u_int key_len; 61 u_int iv_len; /* defaults to block_size */ 62 u_int auth_len; 63 u_int discard_len; 64 u_int flags; 65 #define CFLAG_CBC (1<<0) 66 #define CFLAG_CHACHAPOLY (1<<1) 67 #define CFLAG_AESCTR (1<<2) 68 #define CFLAG_NONE (1<<3) 69 #ifdef WITH_OPENSSL 70 const EVP_CIPHER *(*evptype)(void); 71 #else 72 void *ignored; 73 #endif 74 }; 75 76 static const struct sshcipher ciphers[] = { 77 #ifdef WITH_SSH1 78 { "des", SSH_CIPHER_DES, 8, 8, 0, 0, 0, 1, EVP_des_cbc }, 79 { "3des", SSH_CIPHER_3DES, 8, 16, 0, 0, 0, 1, evp_ssh1_3des }, 80 { "blowfish", SSH_CIPHER_BLOWFISH, 8, 32, 0, 0, 0, 1, evp_ssh1_bf }, 81 #endif 82 #ifdef WITH_OPENSSL 83 { "none", SSH_CIPHER_NONE, 8, 0, 0, 0, 0, 0, EVP_enc_null }, 84 { "3des-cbc", SSH_CIPHER_SSH2, 8, 24, 0, 0, 0, 1, EVP_des_ede3_cbc }, 85 { "blowfish-cbc", 86 SSH_CIPHER_SSH2, 8, 16, 0, 0, 0, 1, EVP_bf_cbc }, 87 { "cast128-cbc", 88 SSH_CIPHER_SSH2, 8, 16, 0, 0, 0, 1, EVP_cast5_cbc }, 89 { "arcfour", SSH_CIPHER_SSH2, 8, 16, 0, 0, 0, 0, EVP_rc4 }, 90 { "arcfour128", SSH_CIPHER_SSH2, 8, 16, 0, 0, 1536, 0, EVP_rc4 }, 91 { "arcfour256", SSH_CIPHER_SSH2, 8, 32, 0, 0, 1536, 0, EVP_rc4 }, 92 { "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, 0, 0, 0, 1, EVP_aes_128_cbc }, 93 { "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, 0, 0, 0, 1, EVP_aes_192_cbc }, 94 { "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 1, EVP_aes_256_cbc }, 95 { "rijndael-cbc@lysator.liu.se", 96 SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 1, EVP_aes_256_cbc }, 97 { "aes128-ctr", SSH_CIPHER_SSH2, 16, 16, 0, 0, 0, 0, EVP_aes_128_ctr }, 98 { "aes192-ctr", SSH_CIPHER_SSH2, 16, 24, 0, 0, 0, 0, EVP_aes_192_ctr }, 99 { "aes256-ctr", SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 0, EVP_aes_256_ctr }, 100 { "aes128-gcm@openssh.com", 101 SSH_CIPHER_SSH2, 16, 16, 12, 16, 0, 0, EVP_aes_128_gcm }, 102 { "aes256-gcm@openssh.com", 103 SSH_CIPHER_SSH2, 16, 32, 12, 16, 0, 0, EVP_aes_256_gcm }, 104 #else 105 { "aes128-ctr", SSH_CIPHER_SSH2, 16, 16, 0, 0, 0, CFLAG_AESCTR, NULL }, 106 { "aes192-ctr", SSH_CIPHER_SSH2, 16, 24, 0, 0, 0, CFLAG_AESCTR, NULL }, 107 { "aes256-ctr", SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, CFLAG_AESCTR, NULL }, 108 { "none", SSH_CIPHER_NONE, 8, 0, 0, 0, 0, CFLAG_NONE, NULL }, 109 #endif 110 { "chacha20-poly1305@openssh.com", 111 SSH_CIPHER_SSH2, 8, 64, 0, 16, 0, CFLAG_CHACHAPOLY, NULL }, 112 113 { NULL, SSH_CIPHER_INVALID, 0, 0, 0, 0, 0, 0, NULL } 114 }; 115 116 /*--*/ 117 118 /* Returns a comma-separated list of supported ciphers. */ 119 char * 120 cipher_alg_list(char sep, int auth_only) 121 { 122 char *tmp, *ret = NULL; 123 size_t nlen, rlen = 0; 124 const struct sshcipher *c; 125 126 for (c = ciphers; c->name != NULL; c++) { 127 if (c->number != SSH_CIPHER_SSH2) 128 continue; 129 if (auth_only && c->auth_len == 0) 130 continue; 131 if (ret != NULL) 132 ret[rlen++] = sep; 133 nlen = strlen(c->name); 134 if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) { 135 free(ret); 136 return NULL; 137 } 138 ret = tmp; 139 memcpy(ret + rlen, c->name, nlen + 1); 140 rlen += nlen; 141 } 142 return ret; 143 } 144 145 u_int 146 cipher_blocksize(const struct sshcipher *c) 147 { 148 return (c->block_size); 149 } 150 151 u_int 152 cipher_keylen(const struct sshcipher *c) 153 { 154 return (c->key_len); 155 } 156 157 u_int 158 cipher_seclen(const struct sshcipher *c) 159 { 160 if (strcmp("3des-cbc", c->name) == 0) 161 return 14; 162 return cipher_keylen(c); 163 } 164 165 u_int 166 cipher_authlen(const struct sshcipher *c) 167 { 168 return (c->auth_len); 169 } 170 171 u_int 172 cipher_ivlen(const struct sshcipher *c) 173 { 174 /* 175 * Default is cipher block size, except for chacha20+poly1305 that 176 * needs no IV. XXX make iv_len == -1 default? 177 */ 178 return (c->iv_len != 0 || (c->flags & CFLAG_CHACHAPOLY) != 0) ? 179 c->iv_len : c->block_size; 180 } 181 182 u_int 183 cipher_get_number(const struct sshcipher *c) 184 { 185 return (c->number); 186 } 187 188 u_int 189 cipher_is_cbc(const struct sshcipher *c) 190 { 191 return (c->flags & CFLAG_CBC) != 0; 192 } 193 194 u_int 195 cipher_mask_ssh1(int client) 196 { 197 u_int mask = 0; 198 mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ 199 mask |= 1 << SSH_CIPHER_BLOWFISH; 200 if (client) { 201 mask |= 1 << SSH_CIPHER_DES; 202 } 203 return mask; 204 } 205 206 const struct sshcipher * 207 cipher_by_name(const char *name) 208 { 209 const struct sshcipher *c; 210 for (c = ciphers; c->name != NULL; c++) 211 if (strcmp(c->name, name) == 0) 212 return c; 213 return NULL; 214 } 215 216 const struct sshcipher * 217 cipher_by_number(int id) 218 { 219 const struct sshcipher *c; 220 for (c = ciphers; c->name != NULL; c++) 221 if (c->number == id) 222 return c; 223 return NULL; 224 } 225 226 #define CIPHER_SEP "," 227 int 228 ciphers_valid(const char *names) 229 { 230 const struct sshcipher *c; 231 char *cipher_list, *cp; 232 char *p; 233 234 if (names == NULL || strcmp(names, "") == 0) 235 return 0; 236 if ((cipher_list = cp = strdup(names)) == NULL) 237 return 0; 238 for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0'; 239 (p = strsep(&cp, CIPHER_SEP))) { 240 c = cipher_by_name(p); 241 if (c == NULL || c->number != SSH_CIPHER_SSH2) { 242 free(cipher_list); 243 return 0; 244 } 245 } 246 free(cipher_list); 247 return 1; 248 } 249 250 /* 251 * Parses the name of the cipher. Returns the number of the corresponding 252 * cipher, or -1 on error. 253 */ 254 255 int 256 cipher_number(const char *name) 257 { 258 const struct sshcipher *c; 259 if (name == NULL) 260 return -1; 261 for (c = ciphers; c->name != NULL; c++) 262 if (strcasecmp(c->name, name) == 0) 263 return c->number; 264 return -1; 265 } 266 267 char * 268 cipher_name(int id) 269 { 270 const struct sshcipher *c = cipher_by_number(id); 271 return (c==NULL) ? "<unknown>" : c->name; 272 } 273 274 const char * 275 cipher_warning_message(const struct sshcipher_ctx *cc) 276 { 277 if (cc == NULL || cc->cipher == NULL) 278 return NULL; 279 if (cc->cipher->number == SSH_CIPHER_DES) 280 return "use of DES is strongly discouraged due to " 281 "cryptographic weaknesses"; 282 return NULL; 283 } 284 285 int 286 cipher_init(struct sshcipher_ctx *cc, const struct sshcipher *cipher, 287 const u_char *key, u_int keylen, const u_char *iv, u_int ivlen, 288 int do_encrypt) 289 { 290 #ifdef WITH_OPENSSL 291 int ret = SSH_ERR_INTERNAL_ERROR; 292 const EVP_CIPHER *type; 293 int klen; 294 u_char *junk, *discard; 295 296 if (cipher->number == SSH_CIPHER_DES) { 297 if (keylen > 8) 298 keylen = 8; 299 } 300 #endif 301 cc->plaintext = (cipher->number == SSH_CIPHER_NONE); 302 cc->encrypt = do_encrypt; 303 304 if (keylen < cipher->key_len || 305 (iv != NULL && ivlen < cipher_ivlen(cipher))) 306 return SSH_ERR_INVALID_ARGUMENT; 307 308 cc->cipher = cipher; 309 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) { 310 return chachapoly_init(&cc->cp_ctx, key, keylen); 311 } 312 #ifndef WITH_OPENSSL 313 if ((cc->cipher->flags & CFLAG_AESCTR) != 0) { 314 aesctr_keysetup(&cc->ac_ctx, key, 8 * keylen, 8 * ivlen); 315 aesctr_ivsetup(&cc->ac_ctx, iv); 316 return 0; 317 } 318 if ((cc->cipher->flags & CFLAG_NONE) != 0) 319 return 0; 320 return SSH_ERR_INVALID_ARGUMENT; 321 #else 322 type = (*cipher->evptype)(); 323 EVP_CIPHER_CTX_init(&cc->evp); 324 if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv, 325 (do_encrypt == CIPHER_ENCRYPT)) == 0) { 326 ret = SSH_ERR_LIBCRYPTO_ERROR; 327 goto bad; 328 } 329 if (cipher_authlen(cipher) && 330 !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_IV_FIXED, 331 -1, (u_char *)iv)) { 332 ret = SSH_ERR_LIBCRYPTO_ERROR; 333 goto bad; 334 } 335 klen = EVP_CIPHER_CTX_key_length(&cc->evp); 336 if (klen > 0 && keylen != (u_int)klen) { 337 if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0) { 338 ret = SSH_ERR_LIBCRYPTO_ERROR; 339 goto bad; 340 } 341 } 342 if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0) { 343 ret = SSH_ERR_LIBCRYPTO_ERROR; 344 goto bad; 345 } 346 347 if (cipher->discard_len > 0) { 348 if ((junk = malloc(cipher->discard_len)) == NULL || 349 (discard = malloc(cipher->discard_len)) == NULL) { 350 free(junk); 351 ret = SSH_ERR_ALLOC_FAIL; 352 goto bad; 353 } 354 ret = EVP_Cipher(&cc->evp, discard, junk, cipher->discard_len); 355 explicit_bzero(discard, cipher->discard_len); 356 free(junk); 357 free(discard); 358 if (ret != 1) { 359 ret = SSH_ERR_LIBCRYPTO_ERROR; 360 bad: 361 EVP_CIPHER_CTX_cleanup(&cc->evp); 362 return ret; 363 } 364 } 365 #endif 366 return 0; 367 } 368 369 /* 370 * cipher_crypt() operates as following: 371 * Copy 'aadlen' bytes (without en/decryption) from 'src' to 'dest'. 372 * Theses bytes are treated as additional authenticated data for 373 * authenticated encryption modes. 374 * En/Decrypt 'len' bytes at offset 'aadlen' from 'src' to 'dest'. 375 * Use 'authlen' bytes at offset 'len'+'aadlen' as the authentication tag. 376 * This tag is written on encryption and verified on decryption. 377 * Both 'aadlen' and 'authlen' can be set to 0. 378 */ 379 int 380 cipher_crypt(struct sshcipher_ctx *cc, u_int seqnr, u_char *dest, 381 const u_char *src, u_int len, u_int aadlen, u_int authlen) 382 { 383 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) { 384 return chachapoly_crypt(&cc->cp_ctx, seqnr, dest, src, 385 len, aadlen, authlen, cc->encrypt); 386 } 387 #ifndef WITH_OPENSSL 388 if ((cc->cipher->flags & CFLAG_AESCTR) != 0) { 389 if (aadlen) 390 memcpy(dest, src, aadlen); 391 aesctr_encrypt_bytes(&cc->ac_ctx, src + aadlen, 392 dest + aadlen, len); 393 return 0; 394 } 395 if ((cc->cipher->flags & CFLAG_NONE) != 0) { 396 memcpy(dest, src, aadlen + len); 397 return 0; 398 } 399 return SSH_ERR_INVALID_ARGUMENT; 400 #else 401 if (authlen) { 402 u_char lastiv[1]; 403 404 if (authlen != cipher_authlen(cc->cipher)) 405 return SSH_ERR_INVALID_ARGUMENT; 406 /* increment IV */ 407 if (!EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_IV_GEN, 408 1, lastiv)) 409 return SSH_ERR_LIBCRYPTO_ERROR; 410 /* set tag on decyption */ 411 if (!cc->encrypt && 412 !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_TAG, 413 authlen, (u_char *)src + aadlen + len)) 414 return SSH_ERR_LIBCRYPTO_ERROR; 415 } 416 if (aadlen) { 417 if (authlen && 418 EVP_Cipher(&cc->evp, NULL, (u_char *)src, aadlen) < 0) 419 return SSH_ERR_LIBCRYPTO_ERROR; 420 memcpy(dest, src, aadlen); 421 } 422 if (len % cc->cipher->block_size) 423 return SSH_ERR_INVALID_ARGUMENT; 424 if (EVP_Cipher(&cc->evp, dest + aadlen, (u_char *)src + aadlen, 425 len) < 0) 426 return SSH_ERR_LIBCRYPTO_ERROR; 427 if (authlen) { 428 /* compute tag (on encrypt) or verify tag (on decrypt) */ 429 if (EVP_Cipher(&cc->evp, NULL, NULL, 0) < 0) 430 return cc->encrypt ? 431 SSH_ERR_LIBCRYPTO_ERROR : SSH_ERR_MAC_INVALID; 432 if (cc->encrypt && 433 !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_GET_TAG, 434 authlen, dest + aadlen + len)) 435 return SSH_ERR_LIBCRYPTO_ERROR; 436 } 437 return 0; 438 #endif 439 } 440 441 /* Extract the packet length, including any decryption necessary beforehand */ 442 int 443 cipher_get_length(struct sshcipher_ctx *cc, u_int *plenp, u_int seqnr, 444 const u_char *cp, u_int len) 445 { 446 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) 447 return chachapoly_get_length(&cc->cp_ctx, plenp, seqnr, 448 cp, len); 449 if (len < 4) 450 return SSH_ERR_MESSAGE_INCOMPLETE; 451 *plenp = get_u32(cp); 452 return 0; 453 } 454 455 int 456 cipher_cleanup(struct sshcipher_ctx *cc) 457 { 458 if (cc == NULL || cc->cipher == NULL) 459 return 0; 460 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) 461 explicit_bzero(&cc->cp_ctx, sizeof(cc->cp_ctx)); 462 else if ((cc->cipher->flags & CFLAG_AESCTR) != 0) 463 explicit_bzero(&cc->ac_ctx, sizeof(cc->ac_ctx)); 464 #ifdef WITH_OPENSSL 465 else if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0) 466 return SSH_ERR_LIBCRYPTO_ERROR; 467 #endif 468 return 0; 469 } 470 471 /* 472 * Selects the cipher, and keys if by computing the MD5 checksum of the 473 * passphrase and using the resulting 16 bytes as the key. 474 */ 475 int 476 cipher_set_key_string(struct sshcipher_ctx *cc, const struct sshcipher *cipher, 477 const char *passphrase, int do_encrypt) 478 { 479 u_char digest[16]; 480 int r = SSH_ERR_INTERNAL_ERROR; 481 482 if ((r = ssh_digest_memory(SSH_DIGEST_MD5, 483 passphrase, strlen(passphrase), 484 digest, sizeof(digest))) != 0) 485 goto out; 486 487 r = cipher_init(cc, cipher, digest, 16, NULL, 0, do_encrypt); 488 out: 489 explicit_bzero(digest, sizeof(digest)); 490 return r; 491 } 492 493 /* 494 * Exports an IV from the sshcipher_ctx required to export the key 495 * state back from the unprivileged child to the privileged parent 496 * process. 497 */ 498 int 499 cipher_get_keyiv_len(const struct sshcipher_ctx *cc) 500 { 501 const struct sshcipher *c = cc->cipher; 502 int ivlen = 0; 503 504 if (c->number == SSH_CIPHER_3DES) 505 ivlen = 24; 506 else if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) 507 ivlen = 0; 508 else if ((cc->cipher->flags & CFLAG_AESCTR) != 0) 509 ivlen = sizeof(cc->ac_ctx.ctr); 510 #ifdef WITH_OPENSSL 511 else 512 ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp); 513 #endif /* WITH_OPENSSL */ 514 return (ivlen); 515 } 516 517 int 518 cipher_get_keyiv(struct sshcipher_ctx *cc, u_char *iv, u_int len) 519 { 520 const struct sshcipher *c = cc->cipher; 521 #ifdef WITH_OPENSSL 522 int evplen; 523 #endif 524 525 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) { 526 if (len != 0) 527 return SSH_ERR_INVALID_ARGUMENT; 528 return 0; 529 } 530 if ((cc->cipher->flags & CFLAG_AESCTR) != 0) { 531 if (len != sizeof(cc->ac_ctx.ctr)) 532 return SSH_ERR_INVALID_ARGUMENT; 533 memcpy(iv, cc->ac_ctx.ctr, len); 534 return 0; 535 } 536 if ((cc->cipher->flags & CFLAG_NONE) != 0) 537 return 0; 538 539 switch (c->number) { 540 #ifdef WITH_OPENSSL 541 case SSH_CIPHER_SSH2: 542 case SSH_CIPHER_DES: 543 case SSH_CIPHER_BLOWFISH: 544 evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); 545 if (evplen == 0) 546 return 0; 547 else if (evplen < 0) 548 return SSH_ERR_LIBCRYPTO_ERROR; 549 if ((u_int)evplen != len) 550 return SSH_ERR_INVALID_ARGUMENT; 551 if (cipher_authlen(c)) { 552 if (!EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_IV_GEN, 553 len, iv)) 554 return SSH_ERR_LIBCRYPTO_ERROR; 555 } else 556 memcpy(iv, cc->evp.iv, len); 557 break; 558 #endif 559 #ifdef WITH_SSH1 560 case SSH_CIPHER_3DES: 561 return ssh1_3des_iv(&cc->evp, 0, iv, 24); 562 #endif 563 default: 564 return SSH_ERR_INVALID_ARGUMENT; 565 } 566 return 0; 567 } 568 569 int 570 cipher_set_keyiv(struct sshcipher_ctx *cc, const u_char *iv) 571 { 572 const struct sshcipher *c = cc->cipher; 573 #ifdef WITH_OPENSSL 574 int evplen = 0; 575 #endif 576 577 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) 578 return 0; 579 if ((cc->cipher->flags & CFLAG_NONE) != 0) 580 return 0; 581 582 switch (c->number) { 583 #ifdef WITH_OPENSSL 584 case SSH_CIPHER_SSH2: 585 case SSH_CIPHER_DES: 586 case SSH_CIPHER_BLOWFISH: 587 evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); 588 if (evplen <= 0) 589 return SSH_ERR_LIBCRYPTO_ERROR; 590 if (cipher_authlen(c)) { 591 /* XXX iv arg is const, but EVP_CIPHER_CTX_ctrl isn't */ 592 if (!EVP_CIPHER_CTX_ctrl(&cc->evp, 593 EVP_CTRL_GCM_SET_IV_FIXED, -1, (void *)iv)) 594 return SSH_ERR_LIBCRYPTO_ERROR; 595 } else 596 memcpy(cc->evp.iv, iv, evplen); 597 break; 598 #endif 599 #ifdef WITH_SSH1 600 case SSH_CIPHER_3DES: 601 return ssh1_3des_iv(&cc->evp, 1, (u_char *)iv, 24); 602 #endif 603 default: 604 return SSH_ERR_INVALID_ARGUMENT; 605 } 606 return 0; 607 } 608 609 #ifdef WITH_OPENSSL 610 #define EVP_X_STATE(evp) (evp).cipher_data 611 #define EVP_X_STATE_LEN(evp) (evp).cipher->ctx_size 612 #endif 613 614 int 615 cipher_get_keycontext(const struct sshcipher_ctx *cc, u_char *dat) 616 { 617 #ifdef WITH_OPENSSL 618 const struct sshcipher *c = cc->cipher; 619 int plen = 0; 620 621 if (c->evptype == EVP_rc4) { 622 plen = EVP_X_STATE_LEN(cc->evp); 623 if (dat == NULL) 624 return (plen); 625 memcpy(dat, EVP_X_STATE(cc->evp), plen); 626 } 627 return (plen); 628 #else 629 return 0; 630 #endif 631 } 632 633 void 634 cipher_set_keycontext(struct sshcipher_ctx *cc, const u_char *dat) 635 { 636 #ifdef WITH_OPENSSL 637 const struct sshcipher *c = cc->cipher; 638 int plen; 639 640 if (c->evptype == EVP_rc4) { 641 plen = EVP_X_STATE_LEN(cc->evp); 642 memcpy(EVP_X_STATE(cc->evp), dat, plen); 643 } 644 #endif 645 } 646