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 "includes.h" 39 40 #include <sys/types.h> 41 42 #include <string.h> 43 #include <stdarg.h> 44 #include <stdio.h> 45 46 #include "cipher.h" 47 #include "misc.h" 48 #include "sshbuf.h" 49 #include "ssherr.h" 50 #include "digest.h" 51 52 #include "openbsd-compat/openssl-compat.h" 53 54 #ifdef WITH_SSH1 55 extern const EVP_CIPHER *evp_ssh1_bf(void); 56 extern const EVP_CIPHER *evp_ssh1_3des(void); 57 extern int ssh1_3des_iv(EVP_CIPHER_CTX *, int, u_char *, int); 58 #endif 59 60 struct sshcipher { 61 char *name; 62 int number; /* for ssh1 only */ 63 u_int block_size; 64 u_int key_len; 65 u_int iv_len; /* defaults to block_size */ 66 u_int auth_len; 67 u_int discard_len; 68 u_int flags; 69 #define CFLAG_CBC (1<<0) 70 #define CFLAG_CHACHAPOLY (1<<1) 71 #define CFLAG_AESCTR (1<<2) 72 #define CFLAG_NONE (1<<3) 73 #ifdef WITH_OPENSSL 74 const EVP_CIPHER *(*evptype)(void); 75 #else 76 void *ignored; 77 #endif 78 }; 79 80 static const struct sshcipher ciphers[] = { 81 #ifdef WITH_SSH1 82 { "des", SSH_CIPHER_DES, 8, 8, 0, 0, 0, 1, EVP_des_cbc }, 83 { "3des", SSH_CIPHER_3DES, 8, 16, 0, 0, 0, 1, evp_ssh1_3des }, 84 # ifndef OPENSSL_NO_BF 85 { "blowfish", SSH_CIPHER_BLOWFISH, 8, 32, 0, 0, 0, 1, evp_ssh1_bf }, 86 # endif /* OPENSSL_NO_BF */ 87 #endif /* WITH_SSH1 */ 88 #ifdef WITH_OPENSSL 89 { "none", SSH_CIPHER_NONE, 8, 0, 0, 0, 0, 0, EVP_enc_null }, 90 { "3des-cbc", SSH_CIPHER_SSH2, 8, 24, 0, 0, 0, 1, EVP_des_ede3_cbc }, 91 # ifndef OPENSSL_NO_BF 92 { "blowfish-cbc", 93 SSH_CIPHER_SSH2, 8, 16, 0, 0, 0, 1, EVP_bf_cbc }, 94 # endif /* OPENSSL_NO_BF */ 95 # ifndef OPENSSL_NO_CAST 96 { "cast128-cbc", 97 SSH_CIPHER_SSH2, 8, 16, 0, 0, 0, 1, EVP_cast5_cbc }, 98 # endif /* OPENSSL_NO_CAST */ 99 # ifndef OPENSSL_NO_RC4 100 { "arcfour", SSH_CIPHER_SSH2, 8, 16, 0, 0, 0, 0, EVP_rc4 }, 101 { "arcfour128", SSH_CIPHER_SSH2, 8, 16, 0, 0, 1536, 0, EVP_rc4 }, 102 { "arcfour256", SSH_CIPHER_SSH2, 8, 32, 0, 0, 1536, 0, EVP_rc4 }, 103 # endif /* OPENSSL_NO_RC4 */ 104 { "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, 0, 0, 0, 1, EVP_aes_128_cbc }, 105 { "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, 0, 0, 0, 1, EVP_aes_192_cbc }, 106 { "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 1, EVP_aes_256_cbc }, 107 { "rijndael-cbc@lysator.liu.se", 108 SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 1, EVP_aes_256_cbc }, 109 { "aes128-ctr", SSH_CIPHER_SSH2, 16, 16, 0, 0, 0, 0, EVP_aes_128_ctr }, 110 { "aes192-ctr", SSH_CIPHER_SSH2, 16, 24, 0, 0, 0, 0, EVP_aes_192_ctr }, 111 { "aes256-ctr", SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 0, EVP_aes_256_ctr }, 112 # ifdef OPENSSL_HAVE_EVPGCM 113 { "aes128-gcm@openssh.com", 114 SSH_CIPHER_SSH2, 16, 16, 12, 16, 0, 0, EVP_aes_128_gcm }, 115 { "aes256-gcm@openssh.com", 116 SSH_CIPHER_SSH2, 16, 32, 12, 16, 0, 0, EVP_aes_256_gcm }, 117 # endif /* OPENSSL_HAVE_EVPGCM */ 118 #else /* WITH_OPENSSL */ 119 { "aes128-ctr", SSH_CIPHER_SSH2, 16, 16, 0, 0, 0, CFLAG_AESCTR, NULL }, 120 { "aes192-ctr", SSH_CIPHER_SSH2, 16, 24, 0, 0, 0, CFLAG_AESCTR, NULL }, 121 { "aes256-ctr", SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, CFLAG_AESCTR, NULL }, 122 { "none", SSH_CIPHER_NONE, 8, 0, 0, 0, 0, CFLAG_NONE, NULL }, 123 #endif /* WITH_OPENSSL */ 124 { "chacha20-poly1305@openssh.com", 125 SSH_CIPHER_SSH2, 8, 64, 0, 16, 0, CFLAG_CHACHAPOLY, NULL }, 126 127 { NULL, SSH_CIPHER_INVALID, 0, 0, 0, 0, 0, 0, NULL } 128 }; 129 130 /*--*/ 131 132 /* Returns a comma-separated list of supported ciphers. */ 133 char * 134 cipher_alg_list(char sep, int auth_only) 135 { 136 char *tmp, *ret = NULL; 137 size_t nlen, rlen = 0; 138 const struct sshcipher *c; 139 140 for (c = ciphers; c->name != NULL; c++) { 141 if (c->number != SSH_CIPHER_SSH2) 142 continue; 143 if (auth_only && c->auth_len == 0) 144 continue; 145 if (ret != NULL) 146 ret[rlen++] = sep; 147 nlen = strlen(c->name); 148 if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) { 149 free(ret); 150 return NULL; 151 } 152 ret = tmp; 153 memcpy(ret + rlen, c->name, nlen + 1); 154 rlen += nlen; 155 } 156 return ret; 157 } 158 159 u_int 160 cipher_blocksize(const struct sshcipher *c) 161 { 162 return (c->block_size); 163 } 164 165 u_int 166 cipher_keylen(const struct sshcipher *c) 167 { 168 return (c->key_len); 169 } 170 171 u_int 172 cipher_seclen(const struct sshcipher *c) 173 { 174 if (strcmp("3des-cbc", c->name) == 0) 175 return 14; 176 return cipher_keylen(c); 177 } 178 179 u_int 180 cipher_authlen(const struct sshcipher *c) 181 { 182 return (c->auth_len); 183 } 184 185 u_int 186 cipher_ivlen(const struct sshcipher *c) 187 { 188 /* 189 * Default is cipher block size, except for chacha20+poly1305 that 190 * needs no IV. XXX make iv_len == -1 default? 191 */ 192 return (c->iv_len != 0 || (c->flags & CFLAG_CHACHAPOLY) != 0) ? 193 c->iv_len : c->block_size; 194 } 195 196 u_int 197 cipher_get_number(const struct sshcipher *c) 198 { 199 return (c->number); 200 } 201 202 u_int 203 cipher_is_cbc(const struct sshcipher *c) 204 { 205 return (c->flags & CFLAG_CBC) != 0; 206 } 207 208 u_int 209 cipher_mask_ssh1(int client) 210 { 211 u_int mask = 0; 212 mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ 213 mask |= 1 << SSH_CIPHER_BLOWFISH; 214 if (client) { 215 mask |= 1 << SSH_CIPHER_DES; 216 } 217 return mask; 218 } 219 220 const struct sshcipher * 221 cipher_by_name(const char *name) 222 { 223 const struct sshcipher *c; 224 for (c = ciphers; c->name != NULL; c++) 225 if (strcmp(c->name, name) == 0) 226 return c; 227 return NULL; 228 } 229 230 const struct sshcipher * 231 cipher_by_number(int id) 232 { 233 const struct sshcipher *c; 234 for (c = ciphers; c->name != NULL; c++) 235 if (c->number == id) 236 return c; 237 return NULL; 238 } 239 240 #define CIPHER_SEP "," 241 int 242 ciphers_valid(const char *names) 243 { 244 const struct sshcipher *c; 245 char *cipher_list, *cp; 246 char *p; 247 248 if (names == NULL || strcmp(names, "") == 0) 249 return 0; 250 if ((cipher_list = cp = strdup(names)) == NULL) 251 return 0; 252 for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0'; 253 (p = strsep(&cp, CIPHER_SEP))) { 254 c = cipher_by_name(p); 255 if (c == NULL || c->number != SSH_CIPHER_SSH2) { 256 free(cipher_list); 257 return 0; 258 } 259 } 260 free(cipher_list); 261 return 1; 262 } 263 264 /* 265 * Parses the name of the cipher. Returns the number of the corresponding 266 * cipher, or -1 on error. 267 */ 268 269 int 270 cipher_number(const char *name) 271 { 272 const struct sshcipher *c; 273 if (name == NULL) 274 return -1; 275 for (c = ciphers; c->name != NULL; c++) 276 if (strcasecmp(c->name, name) == 0) 277 return c->number; 278 return -1; 279 } 280 281 char * 282 cipher_name(int id) 283 { 284 const struct sshcipher *c = cipher_by_number(id); 285 return (c==NULL) ? "<unknown>" : c->name; 286 } 287 288 const char * 289 cipher_warning_message(const struct sshcipher_ctx *cc) 290 { 291 if (cc == NULL || cc->cipher == NULL) 292 return NULL; 293 if (cc->cipher->number == SSH_CIPHER_DES) 294 return "use of DES is strongly discouraged due to " 295 "cryptographic weaknesses"; 296 return NULL; 297 } 298 299 int 300 cipher_init(struct sshcipher_ctx *cc, const struct sshcipher *cipher, 301 const u_char *key, u_int keylen, const u_char *iv, u_int ivlen, 302 int do_encrypt) 303 { 304 #ifdef WITH_OPENSSL 305 int ret = SSH_ERR_INTERNAL_ERROR; 306 const EVP_CIPHER *type; 307 int klen; 308 u_char *junk, *discard; 309 310 if (cipher->number == SSH_CIPHER_DES) { 311 if (keylen > 8) 312 keylen = 8; 313 } 314 #endif 315 cc->plaintext = (cipher->number == SSH_CIPHER_NONE); 316 cc->encrypt = do_encrypt; 317 318 if (keylen < cipher->key_len || 319 (iv != NULL && ivlen < cipher_ivlen(cipher))) 320 return SSH_ERR_INVALID_ARGUMENT; 321 322 cc->cipher = cipher; 323 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) { 324 return chachapoly_init(&cc->cp_ctx, key, keylen); 325 } 326 #ifndef WITH_OPENSSL 327 if ((cc->cipher->flags & CFLAG_AESCTR) != 0) { 328 aesctr_keysetup(&cc->ac_ctx, key, 8 * keylen, 8 * ivlen); 329 aesctr_ivsetup(&cc->ac_ctx, iv); 330 return 0; 331 } 332 if ((cc->cipher->flags & CFLAG_NONE) != 0) 333 return 0; 334 return SSH_ERR_INVALID_ARGUMENT; 335 #else 336 type = (*cipher->evptype)(); 337 EVP_CIPHER_CTX_init(&cc->evp); 338 if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv, 339 (do_encrypt == CIPHER_ENCRYPT)) == 0) { 340 ret = SSH_ERR_LIBCRYPTO_ERROR; 341 goto bad; 342 } 343 if (cipher_authlen(cipher) && 344 !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_IV_FIXED, 345 -1, (u_char *)iv)) { 346 ret = SSH_ERR_LIBCRYPTO_ERROR; 347 goto bad; 348 } 349 klen = EVP_CIPHER_CTX_key_length(&cc->evp); 350 if (klen > 0 && keylen != (u_int)klen) { 351 if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0) { 352 ret = SSH_ERR_LIBCRYPTO_ERROR; 353 goto bad; 354 } 355 } 356 if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0) { 357 ret = SSH_ERR_LIBCRYPTO_ERROR; 358 goto bad; 359 } 360 361 if (cipher->discard_len > 0) { 362 if ((junk = malloc(cipher->discard_len)) == NULL || 363 (discard = malloc(cipher->discard_len)) == NULL) { 364 free(junk); 365 ret = SSH_ERR_ALLOC_FAIL; 366 goto bad; 367 } 368 ret = EVP_Cipher(&cc->evp, discard, junk, cipher->discard_len); 369 explicit_bzero(discard, cipher->discard_len); 370 free(junk); 371 free(discard); 372 if (ret != 1) { 373 ret = SSH_ERR_LIBCRYPTO_ERROR; 374 bad: 375 EVP_CIPHER_CTX_cleanup(&cc->evp); 376 return ret; 377 } 378 } 379 #endif 380 return 0; 381 } 382 383 /* 384 * cipher_crypt() operates as following: 385 * Copy 'aadlen' bytes (without en/decryption) from 'src' to 'dest'. 386 * Theses bytes are treated as additional authenticated data for 387 * authenticated encryption modes. 388 * En/Decrypt 'len' bytes at offset 'aadlen' from 'src' to 'dest'. 389 * Use 'authlen' bytes at offset 'len'+'aadlen' as the authentication tag. 390 * This tag is written on encryption and verified on decryption. 391 * Both 'aadlen' and 'authlen' can be set to 0. 392 */ 393 int 394 cipher_crypt(struct sshcipher_ctx *cc, u_int seqnr, u_char *dest, 395 const u_char *src, u_int len, u_int aadlen, u_int authlen) 396 { 397 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) { 398 return chachapoly_crypt(&cc->cp_ctx, seqnr, dest, src, 399 len, aadlen, authlen, cc->encrypt); 400 } 401 #ifndef WITH_OPENSSL 402 if ((cc->cipher->flags & CFLAG_AESCTR) != 0) { 403 if (aadlen) 404 memcpy(dest, src, aadlen); 405 aesctr_encrypt_bytes(&cc->ac_ctx, src + aadlen, 406 dest + aadlen, len); 407 return 0; 408 } 409 if ((cc->cipher->flags & CFLAG_NONE) != 0) { 410 memcpy(dest, src, aadlen + len); 411 return 0; 412 } 413 return SSH_ERR_INVALID_ARGUMENT; 414 #else 415 if (authlen) { 416 u_char lastiv[1]; 417 418 if (authlen != cipher_authlen(cc->cipher)) 419 return SSH_ERR_INVALID_ARGUMENT; 420 /* increment IV */ 421 if (!EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_IV_GEN, 422 1, lastiv)) 423 return SSH_ERR_LIBCRYPTO_ERROR; 424 /* set tag on decyption */ 425 if (!cc->encrypt && 426 !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_TAG, 427 authlen, (u_char *)src + aadlen + len)) 428 return SSH_ERR_LIBCRYPTO_ERROR; 429 } 430 if (aadlen) { 431 if (authlen && 432 EVP_Cipher(&cc->evp, NULL, (u_char *)src, aadlen) < 0) 433 return SSH_ERR_LIBCRYPTO_ERROR; 434 memcpy(dest, src, aadlen); 435 } 436 if (len % cc->cipher->block_size) 437 return SSH_ERR_INVALID_ARGUMENT; 438 if (EVP_Cipher(&cc->evp, dest + aadlen, (u_char *)src + aadlen, 439 len) < 0) 440 return SSH_ERR_LIBCRYPTO_ERROR; 441 if (authlen) { 442 /* compute tag (on encrypt) or verify tag (on decrypt) */ 443 if (EVP_Cipher(&cc->evp, NULL, NULL, 0) < 0) 444 return cc->encrypt ? 445 SSH_ERR_LIBCRYPTO_ERROR : SSH_ERR_MAC_INVALID; 446 if (cc->encrypt && 447 !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_GET_TAG, 448 authlen, dest + aadlen + len)) 449 return SSH_ERR_LIBCRYPTO_ERROR; 450 } 451 return 0; 452 #endif 453 } 454 455 /* Extract the packet length, including any decryption necessary beforehand */ 456 int 457 cipher_get_length(struct sshcipher_ctx *cc, u_int *plenp, u_int seqnr, 458 const u_char *cp, u_int len) 459 { 460 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) 461 return chachapoly_get_length(&cc->cp_ctx, plenp, seqnr, 462 cp, len); 463 if (len < 4) 464 return SSH_ERR_MESSAGE_INCOMPLETE; 465 *plenp = get_u32(cp); 466 return 0; 467 } 468 469 int 470 cipher_cleanup(struct sshcipher_ctx *cc) 471 { 472 if (cc == NULL || cc->cipher == NULL) 473 return 0; 474 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) 475 explicit_bzero(&cc->cp_ctx, sizeof(cc->cp_ctx)); 476 else if ((cc->cipher->flags & CFLAG_AESCTR) != 0) 477 explicit_bzero(&cc->ac_ctx, sizeof(cc->ac_ctx)); 478 #ifdef WITH_OPENSSL 479 else if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0) 480 return SSH_ERR_LIBCRYPTO_ERROR; 481 #endif 482 return 0; 483 } 484 485 /* 486 * Selects the cipher, and keys if by computing the MD5 checksum of the 487 * passphrase and using the resulting 16 bytes as the key. 488 */ 489 int 490 cipher_set_key_string(struct sshcipher_ctx *cc, const struct sshcipher *cipher, 491 const char *passphrase, int do_encrypt) 492 { 493 u_char digest[16]; 494 int r = SSH_ERR_INTERNAL_ERROR; 495 496 if ((r = ssh_digest_memory(SSH_DIGEST_MD5, 497 passphrase, strlen(passphrase), 498 digest, sizeof(digest))) != 0) 499 goto out; 500 501 r = cipher_init(cc, cipher, digest, 16, NULL, 0, do_encrypt); 502 out: 503 explicit_bzero(digest, sizeof(digest)); 504 return r; 505 } 506 507 /* 508 * Exports an IV from the sshcipher_ctx required to export the key 509 * state back from the unprivileged child to the privileged parent 510 * process. 511 */ 512 int 513 cipher_get_keyiv_len(const struct sshcipher_ctx *cc) 514 { 515 const struct sshcipher *c = cc->cipher; 516 int ivlen = 0; 517 518 if (c->number == SSH_CIPHER_3DES) 519 ivlen = 24; 520 else if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) 521 ivlen = 0; 522 else if ((cc->cipher->flags & CFLAG_AESCTR) != 0) 523 ivlen = sizeof(cc->ac_ctx.ctr); 524 #ifdef WITH_OPENSSL 525 else 526 ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp); 527 #endif /* WITH_OPENSSL */ 528 return (ivlen); 529 } 530 531 int 532 cipher_get_keyiv(struct sshcipher_ctx *cc, u_char *iv, u_int len) 533 { 534 const struct sshcipher *c = cc->cipher; 535 #ifdef WITH_OPENSSL 536 int evplen; 537 #endif 538 539 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) { 540 if (len != 0) 541 return SSH_ERR_INVALID_ARGUMENT; 542 return 0; 543 } 544 if ((cc->cipher->flags & CFLAG_AESCTR) != 0) { 545 if (len != sizeof(cc->ac_ctx.ctr)) 546 return SSH_ERR_INVALID_ARGUMENT; 547 memcpy(iv, cc->ac_ctx.ctr, len); 548 return 0; 549 } 550 if ((cc->cipher->flags & CFLAG_NONE) != 0) 551 return 0; 552 553 switch (c->number) { 554 #ifdef WITH_OPENSSL 555 case SSH_CIPHER_SSH2: 556 case SSH_CIPHER_DES: 557 case SSH_CIPHER_BLOWFISH: 558 evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); 559 if (evplen == 0) 560 return 0; 561 else if (evplen < 0) 562 return SSH_ERR_LIBCRYPTO_ERROR; 563 if ((u_int)evplen != len) 564 return SSH_ERR_INVALID_ARGUMENT; 565 #ifndef OPENSSL_HAVE_EVPCTR 566 if (c->evptype == evp_aes_128_ctr) 567 ssh_aes_ctr_iv(&cc->evp, 0, iv, len); 568 else 569 #endif 570 if (cipher_authlen(c)) { 571 if (!EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_IV_GEN, 572 len, iv)) 573 return SSH_ERR_LIBCRYPTO_ERROR; 574 } else 575 memcpy(iv, cc->evp.iv, len); 576 break; 577 #endif 578 #ifdef WITH_SSH1 579 case SSH_CIPHER_3DES: 580 return ssh1_3des_iv(&cc->evp, 0, iv, 24); 581 #endif 582 default: 583 return SSH_ERR_INVALID_ARGUMENT; 584 } 585 return 0; 586 } 587 588 int 589 cipher_set_keyiv(struct sshcipher_ctx *cc, const u_char *iv) 590 { 591 const struct sshcipher *c = cc->cipher; 592 #ifdef WITH_OPENSSL 593 int evplen = 0; 594 #endif 595 596 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) 597 return 0; 598 if ((cc->cipher->flags & CFLAG_NONE) != 0) 599 return 0; 600 601 switch (c->number) { 602 #ifdef WITH_OPENSSL 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 SSH_ERR_LIBCRYPTO_ERROR; 609 if (cipher_authlen(c)) { 610 /* XXX iv arg is const, but EVP_CIPHER_CTX_ctrl isn't */ 611 if (!EVP_CIPHER_CTX_ctrl(&cc->evp, 612 EVP_CTRL_GCM_SET_IV_FIXED, -1, (void *)iv)) 613 return SSH_ERR_LIBCRYPTO_ERROR; 614 } else 615 memcpy(cc->evp.iv, iv, evplen); 616 break; 617 #endif 618 #ifdef WITH_SSH1 619 case SSH_CIPHER_3DES: 620 return ssh1_3des_iv(&cc->evp, 1, (u_char *)iv, 24); 621 #endif 622 default: 623 return SSH_ERR_INVALID_ARGUMENT; 624 } 625 return 0; 626 } 627 628 #ifdef WITH_OPENSSL 629 #define EVP_X_STATE(evp) (evp).cipher_data 630 #define EVP_X_STATE_LEN(evp) (evp).cipher->ctx_size 631 #endif 632 633 int 634 cipher_get_keycontext(const struct sshcipher_ctx *cc, u_char *dat) 635 { 636 #if defined(WITH_OPENSSL) && !defined(OPENSSL_NO_RC4) 637 const struct sshcipher *c = cc->cipher; 638 int plen = 0; 639 640 if (c->evptype == EVP_rc4) { 641 plen = EVP_X_STATE_LEN(cc->evp); 642 if (dat == NULL) 643 return (plen); 644 memcpy(dat, EVP_X_STATE(cc->evp), plen); 645 } 646 return (plen); 647 #else 648 return 0; 649 #endif 650 } 651 652 void 653 cipher_set_keycontext(struct sshcipher_ctx *cc, const u_char *dat) 654 { 655 #if defined(WITH_OPENSSL) && !defined(OPENSSL_NO_RC4) 656 const struct sshcipher *c = cc->cipher; 657 int plen; 658 659 if (c->evptype == EVP_rc4) { 660 plen = EVP_X_STATE_LEN(cc->evp); 661 memcpy(EVP_X_STATE(cc->evp), dat, plen); 662 } 663 #endif 664 } 665