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" 38 RCSID("$OpenBSD: cipher.c,v 1.62 2002/11/21 22:45:31 markus Exp $"); 39 40 #include "xmalloc.h" 41 #include "log.h" 42 #include "cipher.h" 43 44 #include <openssl/md5.h> 45 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 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); 57 58 struct Cipher { 59 char *name; 60 int number; /* for ssh1 only */ 61 u_int block_size; 62 u_int key_len; 63 const EVP_CIPHER *(*evptype)(void); 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 }, 74 #if OPENSSL_VERSION_NUMBER < 0x00907000L 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 }, 78 { "rijndael-cbc@lysator.liu.se", 79 SSH_CIPHER_SSH2, 16, 32, evp_rijndael }, 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 87 88 { NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL } 89 }; 90 91 /*--*/ 92 93 u_int 94 cipher_blocksize(Cipher *c) 95 { 96 return (c->block_size); 97 } 98 99 u_int 100 cipher_keylen(Cipher *c) 101 { 102 return (c->key_len); 103 } 104 105 u_int 106 cipher_get_number(Cipher *c) 107 { 108 return (c->number); 109 } 110 111 u_int 112 cipher_mask_ssh1(int client) 113 { 114 u_int mask = 0; 115 mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ 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'; 155 (p = strsep(&cp, CIPHER_SEP))) { 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, 194 const u_char *key, u_int keylen, const u_char *iv, u_int ivlen, 195 int encrypt) 196 { 197 static int dowarn = 1; 198 #ifdef SSH_OLD_EVP 199 EVP_CIPHER *type; 200 #else 201 const EVP_CIPHER *type; 202 #endif 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); 215 216 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; 223 224 type = (*cipher->evptype)(); 225 226 EVP_CIPHER_CTX_init(&cc->evp); 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 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) { 242 debug2("cipher_init: set keylen (%d -> %d)", klen, keylen); 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); 250 #endif 251 } 252 253 void 254 cipher_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len) 255 { 256 if (len % cc->cipher->block_size) 257 fatal("cipher_encrypt: bad plaintext length %d", len); 258 #ifdef SSH_OLD_EVP 259 EVP_Cipher(&cc->evp, dest, (u_char *)src, len); 260 #else 261 if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0) 262 fatal("evp_crypt: EVP_Cipher failed"); 263 #endif 264 } 265 266 void 267 cipher_cleanup(CipherContext *cc) 268 { 269 #ifdef SSH_OLD_EVP 270 EVP_CIPHER_CTX_cleanup(&cc->evp); 271 #else 272 if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0) 273 error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed"); 274 #endif 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, 284 const char *passphrase, int encrypt) 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); 292 293 cipher_init(cc, cipher, digest, 16, NULL, 0, encrypt); 294 295 memset(digest, 0, sizeof(digest)); 296 memset(&md, 0, sizeof(md)); 297 } 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 }; 319 320 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); 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 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 } 359 #endif 360 return (1); 361 } 362 363 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 } 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 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); 381 #endif 382 return (1); 383 } 384 385 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 } 397 398 static const EVP_CIPHER * 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; 411 #ifndef SSH_OLD_EVP 412 ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH; 413 #endif 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 } 439 440 #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 452 static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL; 453 454 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 } 464 465 static const EVP_CIPHER * 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; 473 #ifdef SSH_OLD_EVP 474 ssh1_bf.init = bf_ssh1_init; 475 #endif 476 ssh1_bf.do_cipher = bf_ssh1_cipher; 477 ssh1_bf.key_len = 32; 478 return (&ssh1_bf); 479 } 480 481 #if OPENSSL_VERSION_NUMBER < 0x00907000L 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 } 510 511 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 } 556 557 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 } 569 570 static const EVP_CIPHER * 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; 583 #ifndef SSH_OLD_EVP 584 rijndal_cbc.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH | 585 EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CUSTOM_IV; 586 #endif 587 return (&rijndal_cbc); 588 } 589 #endif 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) 625 fatal("%s: wrong iv length %d != %d", __func__, 626 evplen, len); 627 628 #if OPENSSL_VERSION_NUMBER < 0x00907000L 629 if (c->evptype == evp_rijndael) { 630 struct ssh_rijndael_ctx *aesc; 631 632 aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp); 633 if (aesc == NULL) 634 fatal("%s: no rijndael context", __func__); 635 civ = aesc->r_iv; 636 } else 637 #endif 638 { 639 civ = cc->evp.iv; 640 } 641 break; 642 case SSH_CIPHER_3DES: { 643 struct ssh1_3des_ctx *desc; 644 if (len != 24) 645 fatal("%s: bad 3des iv length: %d", __func__, len); 646 desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); 647 if (desc == NULL) 648 fatal("%s: no 3des context", __func__); 649 debug3("%s: Copying 3DES IV", __func__); 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: 656 fatal("%s: bad cipher %d", __func__, c->number); 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; 675 676 #if OPENSSL_VERSION_NUMBER < 0x00907000L 677 if (c->evptype == evp_rijndael) { 678 struct ssh_rijndael_ctx *aesc; 679 680 aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp); 681 if (aesc == NULL) 682 fatal("%s: no rijndael context", __func__); 683 div = aesc->r_iv; 684 } else 685 #endif 686 { 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) 694 fatal("%s: no 3des context", __func__); 695 debug3("%s: Installed 3DES IV", __func__); 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: 702 fatal("%s: bad cipher %d", __func__, c->number); 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; 719 int plen = 0; 720 721 if (c->evptype == EVP_rc4) { 722 plen = EVP_X_STATE_LEN(cc->evp); 723 if (dat == NULL) 724 return (plen); 725 memcpy(dat, EVP_X_STATE(cc->evp), plen); 726 } 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; 735 736 if (c->evptype == EVP_rc4) { 737 plen = EVP_X_STATE_LEN(cc->evp); 738 memcpy(EVP_X_STATE(cc->evp), dat, plen); 739 } 740 } 741