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 1.61 2002/07/12 15:50:17 markus Exp $"); 39 RCSID("$FreeBSD$"); 40 41 #include "xmalloc.h" 42 #include "log.h" 43 #include "cipher.h" 44 45 #include <openssl/md5.h> 46 47 #if OPENSSL_VERSION_NUMBER < 0x00906000L 48 #define SSH_OLD_EVP 49 #define EVP_CIPHER_CTX_get_app_data(e) ((e)->app_data) 50 #endif 51 52 #if OPENSSL_VERSION_NUMBER < 0x00907000L 53 #include "rijndael.h" 54 static const EVP_CIPHER *evp_rijndael(void); 55 #endif 56 static const EVP_CIPHER *evp_ssh1_3des(void); 57 static const EVP_CIPHER *evp_ssh1_bf(void); 58 59 struct Cipher { 60 char *name; 61 int number; /* for ssh1 only */ 62 u_int block_size; 63 u_int key_len; 64 const EVP_CIPHER *(*evptype)(void); 65 } ciphers[] = { 66 { "none", SSH_CIPHER_NONE, 8, 0, EVP_enc_null }, 67 { "des", SSH_CIPHER_DES, 8, 8, EVP_des_cbc }, 68 { "3des", SSH_CIPHER_3DES, 8, 16, evp_ssh1_3des }, 69 { "blowfish", SSH_CIPHER_BLOWFISH, 8, 32, evp_ssh1_bf }, 70 71 { "3des-cbc", SSH_CIPHER_SSH2, 8, 24, EVP_des_ede3_cbc }, 72 { "blowfish-cbc", SSH_CIPHER_SSH2, 8, 16, EVP_bf_cbc }, 73 { "cast128-cbc", SSH_CIPHER_SSH2, 8, 16, EVP_cast5_cbc }, 74 { "arcfour", SSH_CIPHER_SSH2, 8, 16, EVP_rc4 }, 75 #if OPENSSL_VERSION_NUMBER < 0x00907000L 76 { "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, evp_rijndael }, 77 { "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, evp_rijndael }, 78 { "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, evp_rijndael }, 79 { "rijndael-cbc@lysator.liu.se", 80 SSH_CIPHER_SSH2, 16, 32, evp_rijndael }, 81 #else 82 { "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, EVP_aes_128_cbc }, 83 { "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, EVP_aes_192_cbc }, 84 { "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, EVP_aes_256_cbc }, 85 { "rijndael-cbc@lysator.liu.se", 86 SSH_CIPHER_SSH2, 16, 32, EVP_aes_256_cbc }, 87 #endif 88 89 { NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL } 90 }; 91 92 /*--*/ 93 94 u_int 95 cipher_blocksize(Cipher *c) 96 { 97 return (c->block_size); 98 } 99 100 u_int 101 cipher_keylen(Cipher *c) 102 { 103 return (c->key_len); 104 } 105 106 u_int 107 cipher_get_number(Cipher *c) 108 { 109 return (c->number); 110 } 111 112 u_int 113 cipher_mask_ssh1(int client) 114 { 115 u_int mask = 0; 116 mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ 117 mask |= 1 << SSH_CIPHER_BLOWFISH; 118 if (client) { 119 mask |= 1 << SSH_CIPHER_DES; 120 } 121 return mask; 122 } 123 124 Cipher * 125 cipher_by_name(const char *name) 126 { 127 Cipher *c; 128 for (c = ciphers; c->name != NULL; c++) 129 if (strcasecmp(c->name, name) == 0) 130 return c; 131 return NULL; 132 } 133 134 Cipher * 135 cipher_by_number(int id) 136 { 137 Cipher *c; 138 for (c = ciphers; c->name != NULL; c++) 139 if (c->number == id) 140 return c; 141 return NULL; 142 } 143 144 #define CIPHER_SEP "," 145 int 146 ciphers_valid(const char *names) 147 { 148 Cipher *c; 149 char *ciphers, *cp; 150 char *p; 151 152 if (names == NULL || strcmp(names, "") == 0) 153 return 0; 154 ciphers = cp = xstrdup(names); 155 for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0'; 156 (p = strsep(&cp, CIPHER_SEP))) { 157 c = cipher_by_name(p); 158 if (c == NULL || c->number != SSH_CIPHER_SSH2) { 159 debug("bad cipher %s [%s]", p, names); 160 xfree(ciphers); 161 return 0; 162 } else { 163 debug3("cipher ok: %s [%s]", p, names); 164 } 165 } 166 debug3("ciphers ok: [%s]", names); 167 xfree(ciphers); 168 return 1; 169 } 170 171 /* 172 * Parses the name of the cipher. Returns the number of the corresponding 173 * cipher, or -1 on error. 174 */ 175 176 int 177 cipher_number(const char *name) 178 { 179 Cipher *c; 180 if (name == NULL) 181 return -1; 182 c = cipher_by_name(name); 183 return (c==NULL) ? -1 : c->number; 184 } 185 186 char * 187 cipher_name(int id) 188 { 189 Cipher *c = cipher_by_number(id); 190 return (c==NULL) ? "<unknown>" : c->name; 191 } 192 193 void 194 cipher_init(CipherContext *cc, Cipher *cipher, 195 const u_char *key, u_int keylen, const u_char *iv, u_int ivlen, 196 int encrypt) 197 { 198 static int dowarn = 1; 199 #ifdef SSH_OLD_EVP 200 EVP_CIPHER *type; 201 #else 202 const EVP_CIPHER *type; 203 #endif 204 int klen; 205 206 if (cipher->number == SSH_CIPHER_DES) { 207 if (dowarn) { 208 error("Warning: use of DES is strongly discouraged " 209 "due to cryptographic weaknesses"); 210 dowarn = 0; 211 } 212 if (keylen > 8) 213 keylen = 8; 214 } 215 cc->plaintext = (cipher->number == SSH_CIPHER_NONE); 216 217 if (keylen < cipher->key_len) 218 fatal("cipher_init: key length %d is insufficient for %s.", 219 keylen, cipher->name); 220 if (iv != NULL && ivlen < cipher->block_size) 221 fatal("cipher_init: iv length %d is insufficient for %s.", 222 ivlen, cipher->name); 223 cc->cipher = cipher; 224 225 type = (*cipher->evptype)(); 226 227 EVP_CIPHER_CTX_init(&cc->evp); 228 #ifdef SSH_OLD_EVP 229 if (type->key_len > 0 && type->key_len != keylen) { 230 debug("cipher_init: set keylen (%d -> %d)", 231 type->key_len, keylen); 232 type->key_len = keylen; 233 } 234 EVP_CipherInit(&cc->evp, type, (u_char *)key, (u_char *)iv, 235 (encrypt == CIPHER_ENCRYPT)); 236 #else 237 if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv, 238 (encrypt == CIPHER_ENCRYPT)) == 0) 239 fatal("cipher_init: EVP_CipherInit failed for %s", 240 cipher->name); 241 klen = EVP_CIPHER_CTX_key_length(&cc->evp); 242 if (klen > 0 && keylen != klen) { 243 debug("cipher_init: set keylen (%d -> %d)", klen, keylen); 244 if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0) 245 fatal("cipher_init: set keylen failed (%d -> %d)", 246 klen, keylen); 247 } 248 if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0) 249 fatal("cipher_init: EVP_CipherInit: set key failed for %s", 250 cipher->name); 251 #endif 252 } 253 254 void 255 cipher_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len) 256 { 257 if (len % cc->cipher->block_size) 258 fatal("cipher_encrypt: bad plaintext length %d", len); 259 #ifdef SSH_OLD_EVP 260 EVP_Cipher(&cc->evp, dest, (u_char *)src, len); 261 #else 262 if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0) 263 fatal("evp_crypt: EVP_Cipher failed"); 264 #endif 265 } 266 267 void 268 cipher_cleanup(CipherContext *cc) 269 { 270 #ifdef SSH_OLD_EVP 271 EVP_CIPHER_CTX_cleanup(&cc->evp); 272 #else 273 if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0) 274 error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed"); 275 #endif 276 } 277 278 /* 279 * Selects the cipher, and keys if by computing the MD5 checksum of the 280 * passphrase and using the resulting 16 bytes as the key. 281 */ 282 283 void 284 cipher_set_key_string(CipherContext *cc, Cipher *cipher, 285 const char *passphrase, int encrypt) 286 { 287 MD5_CTX md; 288 u_char digest[16]; 289 290 MD5_Init(&md); 291 MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase)); 292 MD5_Final(digest, &md); 293 294 cipher_init(cc, cipher, digest, 16, NULL, 0, encrypt); 295 296 memset(digest, 0, sizeof(digest)); 297 memset(&md, 0, sizeof(md)); 298 } 299 300 /* Implementations for other non-EVP ciphers */ 301 302 /* 303 * This is used by SSH1: 304 * 305 * What kind of triple DES are these 2 routines? 306 * 307 * Why is there a redundant initialization vector? 308 * 309 * If only iv3 was used, then, this would till effect have been 310 * outer-cbc. However, there is also a private iv1 == iv2 which 311 * perhaps makes differential analysis easier. On the other hand, the 312 * private iv1 probably makes the CRC-32 attack ineffective. This is a 313 * result of that there is no longer any known iv1 to use when 314 * choosing the X block. 315 */ 316 struct ssh1_3des_ctx 317 { 318 EVP_CIPHER_CTX k1, k2, k3; 319 }; 320 321 static int 322 ssh1_3des_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, 323 int enc) 324 { 325 struct ssh1_3des_ctx *c; 326 u_char *k1, *k2, *k3; 327 328 if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { 329 c = xmalloc(sizeof(*c)); 330 EVP_CIPHER_CTX_set_app_data(ctx, c); 331 } 332 if (key == NULL) 333 return (1); 334 if (enc == -1) 335 enc = ctx->encrypt; 336 k1 = k2 = k3 = (u_char *) key; 337 k2 += 8; 338 if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) { 339 if (enc) 340 k3 += 16; 341 else 342 k1 += 16; 343 } 344 EVP_CIPHER_CTX_init(&c->k1); 345 EVP_CIPHER_CTX_init(&c->k2); 346 EVP_CIPHER_CTX_init(&c->k3); 347 #ifdef SSH_OLD_EVP 348 EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc); 349 EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc); 350 EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc); 351 #else 352 if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 || 353 EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 || 354 EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) { 355 memset(c, 0, sizeof(*c)); 356 xfree(c); 357 EVP_CIPHER_CTX_set_app_data(ctx, NULL); 358 return (0); 359 } 360 #endif 361 return (1); 362 } 363 364 static int 365 ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, u_int len) 366 { 367 struct ssh1_3des_ctx *c; 368 369 if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { 370 error("ssh1_3des_cbc: no context"); 371 return (0); 372 } 373 #ifdef SSH_OLD_EVP 374 EVP_Cipher(&c->k1, dest, (u_char *)src, len); 375 EVP_Cipher(&c->k2, dest, dest, len); 376 EVP_Cipher(&c->k3, dest, dest, len); 377 #else 378 if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 || 379 EVP_Cipher(&c->k2, dest, dest, len) == 0 || 380 EVP_Cipher(&c->k3, dest, dest, len) == 0) 381 return (0); 382 #endif 383 return (1); 384 } 385 386 static int 387 ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx) 388 { 389 struct ssh1_3des_ctx *c; 390 391 if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { 392 memset(c, 0, sizeof(*c)); 393 xfree(c); 394 EVP_CIPHER_CTX_set_app_data(ctx, NULL); 395 } 396 return (1); 397 } 398 399 static const EVP_CIPHER * 400 evp_ssh1_3des(void) 401 { 402 static EVP_CIPHER ssh1_3des; 403 404 memset(&ssh1_3des, 0, sizeof(EVP_CIPHER)); 405 ssh1_3des.nid = NID_undef; 406 ssh1_3des.block_size = 8; 407 ssh1_3des.iv_len = 0; 408 ssh1_3des.key_len = 16; 409 ssh1_3des.init = ssh1_3des_init; 410 ssh1_3des.cleanup = ssh1_3des_cleanup; 411 ssh1_3des.do_cipher = ssh1_3des_cbc; 412 #ifndef SSH_OLD_EVP 413 ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH; 414 #endif 415 return (&ssh1_3des); 416 } 417 418 /* 419 * SSH1 uses a variation on Blowfish, all bytes must be swapped before 420 * and after encryption/decryption. Thus the swap_bytes stuff (yuk). 421 */ 422 static void 423 swap_bytes(const u_char *src, u_char *dst, int n) 424 { 425 u_char c[4]; 426 427 /* Process 4 bytes every lap. */ 428 for (n = n / 4; n > 0; n--) { 429 c[3] = *src++; 430 c[2] = *src++; 431 c[1] = *src++; 432 c[0] = *src++; 433 434 *dst++ = c[0]; 435 *dst++ = c[1]; 436 *dst++ = c[2]; 437 *dst++ = c[3]; 438 } 439 } 440 441 #ifdef SSH_OLD_EVP 442 static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key, 443 const unsigned char *iv, int enc) 444 { 445 if (iv != NULL) 446 memcpy (&(ctx->oiv[0]), iv, 8); 447 memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8); 448 if (key != NULL) 449 BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx), 450 key); 451 } 452 #endif 453 static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL; 454 455 static int 456 bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len) 457 { 458 int ret; 459 460 swap_bytes(in, out, len); 461 ret = (*orig_bf)(ctx, out, out, len); 462 swap_bytes(out, out, len); 463 return (ret); 464 } 465 466 static const EVP_CIPHER * 467 evp_ssh1_bf(void) 468 { 469 static EVP_CIPHER ssh1_bf; 470 471 memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER)); 472 orig_bf = ssh1_bf.do_cipher; 473 ssh1_bf.nid = NID_undef; 474 #ifdef SSH_OLD_EVP 475 ssh1_bf.init = bf_ssh1_init; 476 #endif 477 ssh1_bf.do_cipher = bf_ssh1_cipher; 478 ssh1_bf.key_len = 32; 479 return (&ssh1_bf); 480 } 481 482 #if OPENSSL_VERSION_NUMBER < 0x00907000L 483 /* RIJNDAEL */ 484 #define RIJNDAEL_BLOCKSIZE 16 485 struct ssh_rijndael_ctx 486 { 487 rijndael_ctx r_ctx; 488 u_char r_iv[RIJNDAEL_BLOCKSIZE]; 489 }; 490 491 static int 492 ssh_rijndael_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, 493 int enc) 494 { 495 struct ssh_rijndael_ctx *c; 496 497 if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { 498 c = xmalloc(sizeof(*c)); 499 EVP_CIPHER_CTX_set_app_data(ctx, c); 500 } 501 if (key != NULL) { 502 if (enc == -1) 503 enc = ctx->encrypt; 504 rijndael_set_key(&c->r_ctx, (u_char *)key, 505 8*EVP_CIPHER_CTX_key_length(ctx), enc); 506 } 507 if (iv != NULL) 508 memcpy(c->r_iv, iv, RIJNDAEL_BLOCKSIZE); 509 return (1); 510 } 511 512 static int 513 ssh_rijndael_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, 514 u_int len) 515 { 516 struct ssh_rijndael_ctx *c; 517 u_char buf[RIJNDAEL_BLOCKSIZE]; 518 u_char *cprev, *cnow, *plain, *ivp; 519 int i, j, blocks = len / RIJNDAEL_BLOCKSIZE; 520 521 if (len == 0) 522 return (1); 523 if (len % RIJNDAEL_BLOCKSIZE) 524 fatal("ssh_rijndael_cbc: bad len %d", len); 525 if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { 526 error("ssh_rijndael_cbc: no context"); 527 return (0); 528 } 529 if (ctx->encrypt) { 530 cnow = dest; 531 plain = (u_char *)src; 532 cprev = c->r_iv; 533 for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE, 534 cnow+=RIJNDAEL_BLOCKSIZE) { 535 for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) 536 buf[j] = plain[j] ^ cprev[j]; 537 rijndael_encrypt(&c->r_ctx, buf, cnow); 538 cprev = cnow; 539 } 540 memcpy(c->r_iv, cprev, RIJNDAEL_BLOCKSIZE); 541 } else { 542 cnow = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE); 543 plain = dest+len-RIJNDAEL_BLOCKSIZE; 544 545 memcpy(buf, cnow, RIJNDAEL_BLOCKSIZE); 546 for (i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE, 547 plain-=RIJNDAEL_BLOCKSIZE) { 548 rijndael_decrypt(&c->r_ctx, cnow, plain); 549 ivp = (i == 1) ? c->r_iv : cnow-RIJNDAEL_BLOCKSIZE; 550 for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) 551 plain[j] ^= ivp[j]; 552 } 553 memcpy(c->r_iv, buf, RIJNDAEL_BLOCKSIZE); 554 } 555 return (1); 556 } 557 558 static int 559 ssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx) 560 { 561 struct ssh_rijndael_ctx *c; 562 563 if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { 564 memset(c, 0, sizeof(*c)); 565 xfree(c); 566 EVP_CIPHER_CTX_set_app_data(ctx, NULL); 567 } 568 return (1); 569 } 570 571 static const EVP_CIPHER * 572 evp_rijndael(void) 573 { 574 static EVP_CIPHER rijndal_cbc; 575 576 memset(&rijndal_cbc, 0, sizeof(EVP_CIPHER)); 577 rijndal_cbc.nid = NID_undef; 578 rijndal_cbc.block_size = RIJNDAEL_BLOCKSIZE; 579 rijndal_cbc.iv_len = RIJNDAEL_BLOCKSIZE; 580 rijndal_cbc.key_len = 16; 581 rijndal_cbc.init = ssh_rijndael_init; 582 rijndal_cbc.cleanup = ssh_rijndael_cleanup; 583 rijndal_cbc.do_cipher = ssh_rijndael_cbc; 584 #ifndef SSH_OLD_EVP 585 rijndal_cbc.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH | 586 EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CUSTOM_IV; 587 #endif 588 return (&rijndal_cbc); 589 } 590 #endif 591 592 /* 593 * Exports an IV from the CipherContext required to export the key 594 * state back from the unprivileged child to the privileged parent 595 * process. 596 */ 597 598 int 599 cipher_get_keyiv_len(CipherContext *cc) 600 { 601 Cipher *c = cc->cipher; 602 int ivlen; 603 604 if (c->number == SSH_CIPHER_3DES) 605 ivlen = 24; 606 else 607 ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp); 608 return (ivlen); 609 } 610 611 void 612 cipher_get_keyiv(CipherContext *cc, u_char *iv, u_int len) 613 { 614 Cipher *c = cc->cipher; 615 u_char *civ = NULL; 616 int evplen; 617 618 switch (c->number) { 619 case SSH_CIPHER_SSH2: 620 case SSH_CIPHER_DES: 621 case SSH_CIPHER_BLOWFISH: 622 evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); 623 if (evplen == 0) 624 return; 625 if (evplen != len) 626 fatal("%s: wrong iv length %d != %d", __func__, 627 evplen, len); 628 629 #if OPENSSL_VERSION_NUMBER < 0x00907000L 630 if (c->evptype == evp_rijndael) { 631 struct ssh_rijndael_ctx *aesc; 632 633 aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp); 634 if (aesc == NULL) 635 fatal("%s: no rijndael context", __func__); 636 civ = aesc->r_iv; 637 } else 638 #endif 639 { 640 civ = cc->evp.iv; 641 } 642 break; 643 case SSH_CIPHER_3DES: { 644 struct ssh1_3des_ctx *desc; 645 if (len != 24) 646 fatal("%s: bad 3des iv length: %d", __func__, len); 647 desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); 648 if (desc == NULL) 649 fatal("%s: no 3des context", __func__); 650 debug3("%s: Copying 3DES IV", __func__); 651 memcpy(iv, desc->k1.iv, 8); 652 memcpy(iv + 8, desc->k2.iv, 8); 653 memcpy(iv + 16, desc->k3.iv, 8); 654 return; 655 } 656 default: 657 fatal("%s: bad cipher %d", __func__, c->number); 658 } 659 memcpy(iv, civ, len); 660 } 661 662 void 663 cipher_set_keyiv(CipherContext *cc, u_char *iv) 664 { 665 Cipher *c = cc->cipher; 666 u_char *div = NULL; 667 int evplen = 0; 668 669 switch (c->number) { 670 case SSH_CIPHER_SSH2: 671 case SSH_CIPHER_DES: 672 case SSH_CIPHER_BLOWFISH: 673 evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); 674 if (evplen == 0) 675 return; 676 677 #if OPENSSL_VERSION_NUMBER < 0x00907000L 678 if (c->evptype == evp_rijndael) { 679 struct ssh_rijndael_ctx *aesc; 680 681 aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp); 682 if (aesc == NULL) 683 fatal("%s: no rijndael context", __func__); 684 div = aesc->r_iv; 685 } else 686 #endif 687 { 688 div = cc->evp.iv; 689 } 690 break; 691 case SSH_CIPHER_3DES: { 692 struct ssh1_3des_ctx *desc; 693 desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); 694 if (desc == NULL) 695 fatal("%s: no 3des context", __func__); 696 debug3("%s: Installed 3DES IV", __func__); 697 memcpy(desc->k1.iv, iv, 8); 698 memcpy(desc->k2.iv, iv + 8, 8); 699 memcpy(desc->k3.iv, iv + 16, 8); 700 return; 701 } 702 default: 703 fatal("%s: bad cipher %d", __func__, c->number); 704 } 705 memcpy(div, iv, evplen); 706 } 707 708 #if OPENSSL_VERSION_NUMBER < 0x00907000L 709 #define EVP_X_STATE(evp) &(evp).c 710 #define EVP_X_STATE_LEN(evp) sizeof((evp).c) 711 #else 712 #define EVP_X_STATE(evp) (evp).cipher_data 713 #define EVP_X_STATE_LEN(evp) (evp).cipher->ctx_size 714 #endif 715 716 int 717 cipher_get_keycontext(CipherContext *cc, u_char *dat) 718 { 719 Cipher *c = cc->cipher; 720 int plen = 0; 721 722 if (c->evptype == EVP_rc4) { 723 plen = EVP_X_STATE_LEN(cc->evp); 724 if (dat == NULL) 725 return (plen); 726 memcpy(dat, EVP_X_STATE(cc->evp), plen); 727 } 728 return (plen); 729 } 730 731 void 732 cipher_set_keycontext(CipherContext *cc, u_char *dat) 733 { 734 Cipher *c = cc->cipher; 735 int plen; 736 737 if (c->evptype == EVP_rc4) { 738 plen = EVP_X_STATE_LEN(cc->evp); 739 memcpy(EVP_X_STATE(cc->evp), dat, plen); 740 } 741 } 742