1 /* $NetBSD: cipher.c,v 1.8 2016/03/11 01:55:00 christos Exp $ */ 2 /* $OpenBSD: cipher.c,v 1.101 2015/12/10 17:08:40 mmcc Exp $ */ 3 4 /* 5 * Author: Tatu Ylonen <ylo@cs.hut.fi> 6 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 7 * All rights reserved 8 * 9 * As far as I am concerned, the code I have written for this software 10 * can be used freely for any purpose. Any derived versions of this 11 * software must be clearly marked as such, and if the derived work is 12 * incompatible with the protocol description in the RFC file, it must be 13 * called by a name other than "ssh" or "Secure Shell". 14 * 15 * 16 * Copyright (c) 1999 Niels Provos. All rights reserved. 17 * Copyright (c) 1999, 2000 Markus Friedl. All rights reserved. 18 * 19 * Redistribution and use in source and binary forms, with or without 20 * modification, are permitted provided that the following conditions 21 * are met: 22 * 1. Redistributions of source code must retain the above copyright 23 * notice, this list of conditions and the following disclaimer. 24 * 2. Redistributions in binary form must reproduce the above copyright 25 * notice, this list of conditions and the following disclaimer in the 26 * documentation and/or other materials provided with the distribution. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 29 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 30 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 31 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 33 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 37 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 #include "includes.h" 41 __RCSID("$NetBSD: cipher.c,v 1.8 2016/03/11 01:55:00 christos Exp $"); 42 #include <sys/types.h> 43 44 #include <string.h> 45 #include <stdarg.h> 46 #include <stdio.h> 47 48 #include "cipher.h" 49 #include "misc.h" 50 #include "sshbuf.h" 51 #include "ssherr.h" 52 #include "digest.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 const 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 { "blowfish", SSH_CIPHER_BLOWFISH, 8, 32, 0, 0, 0, 1, evp_ssh1_bf }, 85 #endif 86 #ifdef WITH_OPENSSL 87 { "none", SSH_CIPHER_NONE, 8, 0, 0, 0, 0, 0, EVP_enc_null }, 88 { "3des-cbc", SSH_CIPHER_SSH2, 8, 24, 0, 0, 0, 1, EVP_des_ede3_cbc }, 89 { "blowfish-cbc", 90 SSH_CIPHER_SSH2, 8, 16, 0, 0, 0, 1, EVP_bf_cbc }, 91 { "cast128-cbc", 92 SSH_CIPHER_SSH2, 8, 16, 0, 0, 0, 1, EVP_cast5_cbc }, 93 { "arcfour", SSH_CIPHER_SSH2, 8, 16, 0, 0, 0, 0, EVP_rc4 }, 94 { "arcfour128", SSH_CIPHER_SSH2, 8, 16, 0, 0, 1536, 0, EVP_rc4 }, 95 { "arcfour256", SSH_CIPHER_SSH2, 8, 32, 0, 0, 1536, 0, EVP_rc4 }, 96 { "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, 0, 0, 0, 1, EVP_aes_128_cbc }, 97 { "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, 0, 0, 0, 1, EVP_aes_192_cbc }, 98 { "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 1, EVP_aes_256_cbc }, 99 { "rijndael-cbc@lysator.liu.se", 100 SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 1, EVP_aes_256_cbc }, 101 #ifdef AES_CTR_MT 102 { "aes128-ctr", SSH_CIPHER_SSH2, 16, 16, 0, 0, 0, 0, evp_aes_ctr_mt }, 103 { "aes192-ctr", SSH_CIPHER_SSH2, 16, 24, 0, 0, 0, 0, evp_aes_ctr_mt }, 104 { "aes256-ctr", SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 0, evp_aes_ctr_mt }, 105 #else 106 { "aes128-ctr", SSH_CIPHER_SSH2, 16, 16, 0, 0, 0, 0, EVP_aes_128_ctr }, 107 { "aes192-ctr", SSH_CIPHER_SSH2, 16, 24, 0, 0, 0, 0, EVP_aes_192_ctr }, 108 { "aes256-ctr", SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, 0, EVP_aes_256_ctr }, 109 #endif 110 { "aes128-gcm@openssh.com", 111 SSH_CIPHER_SSH2, 16, 16, 12, 16, 0, 0, EVP_aes_128_gcm }, 112 { "aes256-gcm@openssh.com", 113 SSH_CIPHER_SSH2, 16, 32, 12, 16, 0, 0, EVP_aes_256_gcm }, 114 #else 115 { "aes128-ctr", SSH_CIPHER_SSH2, 16, 16, 0, 0, 0, CFLAG_AESCTR, NULL }, 116 { "aes192-ctr", SSH_CIPHER_SSH2, 16, 24, 0, 0, 0, CFLAG_AESCTR, NULL }, 117 { "aes256-ctr", SSH_CIPHER_SSH2, 16, 32, 0, 0, 0, CFLAG_AESCTR, NULL }, 118 { "none", SSH_CIPHER_NONE, 8, 0, 0, 0, 0, CFLAG_NONE, NULL }, 119 #endif 120 { "chacha20-poly1305@openssh.com", 121 SSH_CIPHER_SSH2, 8, 64, 0, 16, 0, CFLAG_CHACHAPOLY, NULL }, 122 123 { NULL, SSH_CIPHER_INVALID, 0, 0, 0, 0, 0, 0, NULL } 124 }; 125 126 /*--*/ 127 128 /* Returns a comma-separated list of supported ciphers. */ 129 char * 130 cipher_alg_list(char sep, int auth_only) 131 { 132 char *tmp, *ret = NULL; 133 size_t nlen, rlen = 0; 134 const struct sshcipher *c; 135 136 for (c = ciphers; c->name != NULL; c++) { 137 if (c->number != SSH_CIPHER_SSH2) 138 continue; 139 if (auth_only && c->auth_len == 0) 140 continue; 141 if (ret != NULL) 142 ret[rlen++] = sep; 143 nlen = strlen(c->name); 144 if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) { 145 free(ret); 146 return NULL; 147 } 148 ret = tmp; 149 memcpy(ret + rlen, c->name, nlen + 1); 150 rlen += nlen; 151 } 152 return ret; 153 } 154 155 u_int 156 cipher_blocksize(const struct sshcipher *c) 157 { 158 return (c->block_size); 159 } 160 161 u_int 162 cipher_keylen(const struct sshcipher *c) 163 { 164 return (c->key_len); 165 } 166 167 u_int 168 cipher_seclen(const struct sshcipher *c) 169 { 170 if (strcmp("3des-cbc", c->name) == 0) 171 return 14; 172 return cipher_keylen(c); 173 } 174 175 u_int 176 cipher_authlen(const struct sshcipher *c) 177 { 178 return (c->auth_len); 179 } 180 181 u_int 182 cipher_ivlen(const struct sshcipher *c) 183 { 184 /* 185 * Default is cipher block size, except for chacha20+poly1305 that 186 * needs no IV. XXX make iv_len == -1 default? 187 */ 188 return (c->iv_len != 0 || (c->flags & CFLAG_CHACHAPOLY) != 0) ? 189 c->iv_len : c->block_size; 190 } 191 192 u_int 193 cipher_get_number(const struct sshcipher *c) 194 { 195 return (c->number); 196 } 197 198 u_int 199 cipher_is_cbc(const struct sshcipher *c) 200 { 201 return (c->flags & CFLAG_CBC) != 0; 202 } 203 204 u_int 205 cipher_mask_ssh1(int client) 206 { 207 u_int mask = 0; 208 mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ 209 mask |= 1 << SSH_CIPHER_BLOWFISH; 210 if (client) { 211 mask |= 1 << SSH_CIPHER_DES; 212 } 213 return mask; 214 } 215 216 const struct sshcipher * 217 cipher_by_name(const char *name) 218 { 219 const struct sshcipher *c; 220 for (c = ciphers; c->name != NULL; c++) 221 if (strcmp(c->name, name) == 0) 222 return c; 223 return NULL; 224 } 225 226 const struct sshcipher * 227 cipher_by_number(int id) 228 { 229 const struct sshcipher *c; 230 for (c = ciphers; c->name != NULL; c++) 231 if (c->number == id) 232 return c; 233 return NULL; 234 } 235 236 #define CIPHER_SEP "," 237 int 238 ciphers_valid(const char *names) 239 { 240 const struct sshcipher *c; 241 char *cipher_list, *cp; 242 char *p; 243 244 if (names == NULL || strcmp(names, "") == 0) 245 return 0; 246 if ((cipher_list = cp = strdup(names)) == NULL) 247 return 0; 248 for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0'; 249 (p = strsep(&cp, CIPHER_SEP))) { 250 c = cipher_by_name(p); 251 if (c == NULL || (c->number != SSH_CIPHER_SSH2 && 252 c->number != SSH_CIPHER_NONE)) { 253 free(cipher_list); 254 return 0; 255 } 256 } 257 free(cipher_list); 258 return 1; 259 } 260 261 /* 262 * Parses the name of the cipher. Returns the number of the corresponding 263 * cipher, or -1 on error. 264 */ 265 266 int 267 cipher_number(const char *name) 268 { 269 const struct sshcipher *c; 270 if (name == NULL) 271 return -1; 272 for (c = ciphers; c->name != NULL; c++) 273 if (strcasecmp(c->name, name) == 0) 274 return c->number; 275 return -1; 276 } 277 278 const char * 279 cipher_name(int id) 280 { 281 const struct sshcipher *c = cipher_by_number(id); 282 return (c==NULL) ? "<unknown>" : c->name; 283 } 284 285 const char * 286 cipher_warning_message(const struct sshcipher_ctx *cc) 287 { 288 if (cc == NULL || cc->cipher == NULL) 289 return NULL; 290 if (cc->cipher->number == SSH_CIPHER_DES) 291 return "use of DES is strongly discouraged due to " 292 "cryptographic weaknesses"; 293 return NULL; 294 } 295 296 int 297 cipher_init(struct sshcipher_ctx *cc, const struct sshcipher *cipher, 298 const u_char *key, u_int keylen, const u_char *iv, u_int ivlen, 299 int do_encrypt) 300 { 301 #ifdef WITH_OPENSSL 302 int ret = SSH_ERR_INTERNAL_ERROR; 303 const EVP_CIPHER *type; 304 int klen; 305 u_char *junk, *discard; 306 307 if (cipher->number == SSH_CIPHER_DES) { 308 if (keylen > 8) 309 keylen = 8; 310 } 311 #endif 312 cc->plaintext = (cipher->number == SSH_CIPHER_NONE); 313 cc->encrypt = do_encrypt; 314 315 if (keylen < cipher->key_len || 316 (iv != NULL && ivlen < cipher_ivlen(cipher))) 317 return SSH_ERR_INVALID_ARGUMENT; 318 319 cc->cipher = cipher; 320 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) { 321 return chachapoly_init(&cc->cp_ctx, key, keylen); 322 } 323 #ifndef WITH_OPENSSL 324 if ((cc->cipher->flags & CFLAG_AESCTR) != 0) { 325 aesctr_keysetup(&cc->ac_ctx, key, 8 * keylen, 8 * ivlen); 326 aesctr_ivsetup(&cc->ac_ctx, iv); 327 return 0; 328 } 329 if ((cc->cipher->flags & CFLAG_NONE) != 0) 330 return 0; 331 return SSH_ERR_INVALID_ARGUMENT; 332 #else 333 type = (*cipher->evptype)(); 334 EVP_CIPHER_CTX_init(&cc->evp); 335 if (EVP_CipherInit(&cc->evp, type, NULL, __UNCONST(iv), 336 (do_encrypt == CIPHER_ENCRYPT)) == 0) { 337 ret = SSH_ERR_LIBCRYPTO_ERROR; 338 goto bad; 339 } 340 if (cipher_authlen(cipher) && 341 !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_IV_FIXED, 342 -1, __UNCONST(iv))) { 343 ret = SSH_ERR_LIBCRYPTO_ERROR; 344 goto bad; 345 } 346 klen = EVP_CIPHER_CTX_key_length(&cc->evp); 347 if (klen > 0 && keylen != (u_int)klen) { 348 if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0) { 349 ret = SSH_ERR_LIBCRYPTO_ERROR; 350 goto bad; 351 } 352 } 353 if (EVP_CipherInit(&cc->evp, NULL, __UNCONST(key), NULL, -1) == 0) { 354 ret = SSH_ERR_LIBCRYPTO_ERROR; 355 goto bad; 356 } 357 358 if (cipher->discard_len > 0) { 359 if ((junk = malloc(cipher->discard_len)) == NULL || 360 (discard = malloc(cipher->discard_len)) == NULL) { 361 free(junk); 362 ret = SSH_ERR_ALLOC_FAIL; 363 goto bad; 364 } 365 ret = EVP_Cipher(&cc->evp, discard, junk, cipher->discard_len); 366 explicit_bzero(discard, cipher->discard_len); 367 free(junk); 368 free(discard); 369 if (ret != 1) { 370 ret = SSH_ERR_LIBCRYPTO_ERROR; 371 bad: 372 EVP_CIPHER_CTX_cleanup(&cc->evp); 373 return ret; 374 } 375 } 376 #endif 377 return 0; 378 } 379 380 /* 381 * cipher_crypt() operates as following: 382 * Copy 'aadlen' bytes (without en/decryption) from 'src' to 'dest'. 383 * Theses bytes are treated as additional authenticated data for 384 * authenticated encryption modes. 385 * En/Decrypt 'len' bytes at offset 'aadlen' from 'src' to 'dest'. 386 * Use 'authlen' bytes at offset 'len'+'aadlen' as the authentication tag. 387 * This tag is written on encryption and verified on decryption. 388 * Both 'aadlen' and 'authlen' can be set to 0. 389 */ 390 int 391 cipher_crypt(struct sshcipher_ctx *cc, u_int seqnr, u_char *dest, 392 const u_char *src, u_int len, u_int aadlen, u_int authlen) 393 { 394 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) { 395 return chachapoly_crypt(&cc->cp_ctx, seqnr, dest, src, 396 len, aadlen, authlen, cc->encrypt); 397 } 398 #ifndef WITH_OPENSSL 399 if ((cc->cipher->flags & CFLAG_AESCTR) != 0) { 400 if (aadlen) 401 memcpy(dest, src, aadlen); 402 aesctr_encrypt_bytes(&cc->ac_ctx, src + aadlen, 403 dest + aadlen, len); 404 return 0; 405 } 406 if ((cc->cipher->flags & CFLAG_NONE) != 0) { 407 memcpy(dest, src, aadlen + len); 408 return 0; 409 } 410 return SSH_ERR_INVALID_ARGUMENT; 411 #else 412 if (authlen) { 413 u_char lastiv[1]; 414 415 if (authlen != cipher_authlen(cc->cipher)) 416 return SSH_ERR_INVALID_ARGUMENT; 417 /* increment IV */ 418 if (!EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_IV_GEN, 419 1, lastiv)) 420 return SSH_ERR_LIBCRYPTO_ERROR; 421 /* set tag on decyption */ 422 if (!cc->encrypt && 423 !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_TAG, 424 authlen, __UNCONST(src + aadlen + len))) 425 return SSH_ERR_LIBCRYPTO_ERROR; 426 } 427 if (aadlen) { 428 if (authlen && 429 EVP_Cipher(&cc->evp, NULL, (const u_char *)src, aadlen) < 0) 430 return SSH_ERR_LIBCRYPTO_ERROR; 431 memcpy(dest, src, aadlen); 432 } 433 if (len % cc->cipher->block_size) 434 return SSH_ERR_INVALID_ARGUMENT; 435 if (EVP_Cipher(&cc->evp, dest + aadlen, (const u_char *)src + aadlen, 436 len) < 0) 437 return SSH_ERR_LIBCRYPTO_ERROR; 438 if (authlen) { 439 /* compute tag (on encrypt) or verify tag (on decrypt) */ 440 if (EVP_Cipher(&cc->evp, NULL, NULL, 0) < 0) 441 return cc->encrypt ? 442 SSH_ERR_LIBCRYPTO_ERROR : SSH_ERR_MAC_INVALID; 443 if (cc->encrypt && 444 !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_GET_TAG, 445 authlen, dest + aadlen + len)) 446 return SSH_ERR_LIBCRYPTO_ERROR; 447 } 448 return 0; 449 #endif 450 } 451 452 /* Extract the packet length, including any decryption necessary beforehand */ 453 int 454 cipher_get_length(struct sshcipher_ctx *cc, u_int *plenp, u_int seqnr, 455 const u_char *cp, u_int len) 456 { 457 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) 458 return chachapoly_get_length(&cc->cp_ctx, plenp, seqnr, 459 cp, len); 460 if (len < 4) 461 return SSH_ERR_MESSAGE_INCOMPLETE; 462 *plenp = get_u32(cp); 463 return 0; 464 } 465 466 int 467 cipher_cleanup(struct sshcipher_ctx *cc) 468 { 469 if (cc == NULL || cc->cipher == NULL) 470 return 0; 471 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) 472 explicit_bzero(&cc->cp_ctx, sizeof(cc->cp_ctx)); 473 else if ((cc->cipher->flags & CFLAG_AESCTR) != 0) 474 explicit_bzero(&cc->ac_ctx, sizeof(cc->ac_ctx)); 475 #ifdef WITH_OPENSSL 476 else if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0) 477 return SSH_ERR_LIBCRYPTO_ERROR; 478 #endif 479 return 0; 480 } 481 482 /* 483 * Selects the cipher, and keys if by computing the MD5 checksum of the 484 * passphrase and using the resulting 16 bytes as the key. 485 */ 486 int 487 cipher_set_key_string(struct sshcipher_ctx *cc, const struct sshcipher *cipher, 488 const char *passphrase, int do_encrypt) 489 { 490 u_char digest[16]; 491 int r = SSH_ERR_INTERNAL_ERROR; 492 493 if ((r = ssh_digest_memory(SSH_DIGEST_MD5, 494 passphrase, strlen(passphrase), 495 digest, sizeof(digest))) != 0) 496 goto out; 497 498 r = cipher_init(cc, cipher, digest, 16, NULL, 0, do_encrypt); 499 out: 500 explicit_bzero(digest, sizeof(digest)); 501 return r; 502 } 503 504 /* 505 * Exports an IV from the sshcipher_ctx required to export the key 506 * state back from the unprivileged child to the privileged parent 507 * process. 508 */ 509 int 510 cipher_get_keyiv_len(const struct sshcipher_ctx *cc) 511 { 512 const struct sshcipher *c = cc->cipher; 513 int ivlen = 0; 514 515 if (c->number == SSH_CIPHER_3DES) 516 ivlen = 24; 517 else if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) 518 ivlen = 0; 519 else if ((cc->cipher->flags & CFLAG_AESCTR) != 0) 520 ivlen = sizeof(cc->ac_ctx.ctr); 521 #ifdef WITH_OPENSSL 522 else 523 ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp); 524 #endif /* WITH_OPENSSL */ 525 return (ivlen); 526 } 527 528 int 529 cipher_get_keyiv(struct sshcipher_ctx *cc, u_char *iv, u_int len) 530 { 531 const struct sshcipher *c = cc->cipher; 532 #ifdef WITH_OPENSSL 533 int evplen; 534 #endif 535 536 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) { 537 if (len != 0) 538 return SSH_ERR_INVALID_ARGUMENT; 539 return 0; 540 } 541 if ((cc->cipher->flags & CFLAG_AESCTR) != 0) { 542 if (len != sizeof(cc->ac_ctx.ctr)) 543 return SSH_ERR_INVALID_ARGUMENT; 544 memcpy(iv, cc->ac_ctx.ctr, len); 545 return 0; 546 } 547 if ((cc->cipher->flags & CFLAG_NONE) != 0) 548 return 0; 549 550 switch (c->number) { 551 #ifdef WITH_OPENSSL 552 case SSH_CIPHER_NONE: 553 case SSH_CIPHER_SSH2: 554 case SSH_CIPHER_DES: 555 case SSH_CIPHER_BLOWFISH: 556 evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); 557 if (evplen == 0) 558 return 0; 559 else if (evplen < 0) 560 return SSH_ERR_LIBCRYPTO_ERROR; 561 if ((u_int)evplen != len) 562 return SSH_ERR_INVALID_ARGUMENT; 563 if (cipher_authlen(c)) { 564 if (!EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_IV_GEN, 565 len, iv)) 566 return SSH_ERR_LIBCRYPTO_ERROR; 567 } else 568 memcpy(iv, cc->evp.iv, len); 569 break; 570 #endif 571 #ifdef WITH_SSH1 572 case SSH_CIPHER_3DES: 573 return ssh1_3des_iv(&cc->evp, 0, iv, 24); 574 #endif 575 default: 576 return SSH_ERR_INVALID_ARGUMENT; 577 } 578 return 0; 579 } 580 581 int 582 cipher_set_keyiv(struct sshcipher_ctx *cc, const u_char *iv) 583 { 584 const struct sshcipher *c = cc->cipher; 585 #ifdef WITH_OPENSSL 586 int evplen = 0; 587 #endif 588 589 if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) 590 return 0; 591 if ((cc->cipher->flags & CFLAG_NONE) != 0) 592 return 0; 593 594 switch (c->number) { 595 #ifdef WITH_OPENSSL 596 case SSH_CIPHER_NONE: 597 case SSH_CIPHER_SSH2: 598 case SSH_CIPHER_DES: 599 case SSH_CIPHER_BLOWFISH: 600 evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); 601 if (evplen <= 0) 602 return SSH_ERR_LIBCRYPTO_ERROR; 603 if (cipher_authlen(c)) { 604 /* XXX iv arg is const, but EVP_CIPHER_CTX_ctrl isn't */ 605 if (!EVP_CIPHER_CTX_ctrl(&cc->evp, 606 EVP_CTRL_GCM_SET_IV_FIXED, -1, __UNCONST(iv))) 607 return SSH_ERR_LIBCRYPTO_ERROR; 608 } else 609 memcpy(cc->evp.iv, iv, evplen); 610 break; 611 #endif 612 #ifdef WITH_SSH1 613 case SSH_CIPHER_3DES: 614 return ssh1_3des_iv(&cc->evp, 1, __UNCONST(iv), 24); 615 #endif 616 default: 617 return SSH_ERR_INVALID_ARGUMENT; 618 } 619 return 0; 620 } 621 622 #ifdef WITH_OPENSSL 623 #define EVP_X_STATE(evp) (evp).cipher_data 624 #define EVP_X_STATE_LEN(evp) (evp).cipher->ctx_size 625 #endif 626 627 int 628 cipher_get_keycontext(const struct sshcipher_ctx *cc, u_char *dat) 629 { 630 #ifdef WITH_OPENSSL 631 const struct sshcipher *c = cc->cipher; 632 int plen = 0; 633 634 if (c->evptype == EVP_rc4) { 635 plen = EVP_X_STATE_LEN(cc->evp); 636 if (dat == NULL) 637 return (plen); 638 memcpy(dat, EVP_X_STATE(cc->evp), plen); 639 } 640 return (plen); 641 #else 642 return 0; 643 #endif 644 } 645 646 void 647 cipher_set_keycontext(struct sshcipher_ctx *cc, const u_char *dat) 648 { 649 #ifdef WITH_OPENSSL 650 const struct sshcipher *c = cc->cipher; 651 int plen; 652 653 if (c->evptype == EVP_rc4) { 654 plen = EVP_X_STATE_LEN(cc->evp); 655 memcpy(EVP_X_STATE(cc->evp), dat, plen); 656 } 657 #endif 658 } 659