Annotation of src/usr.bin/ssh/cipher.c, Revision 1.26.2.3
1.1 deraadt 1: /*
1.17 deraadt 2: * Author: Tatu Ylonen <ylo@cs.hut.fi>
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
1.26 markus 5: *
1.26.2.3! jason 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.
1.26 markus 15: *
1.26.2.3! jason 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.
1.17 deraadt 35: */
1.1 deraadt 36:
37: #include "includes.h"
1.26.2.3! jason 38: RCSID("$OpenBSD: cipher.c,v 1.37 2000/10/23 19:31:54 markus Exp $");
1.1 deraadt 39:
40: #include "ssh.h"
1.24 markus 41: #include "xmalloc.h"
1.8 deraadt 42:
1.25 markus 43: #include <openssl/md5.h>
1.1 deraadt 44:
1.26.2.3! jason 45:
! 46: /* no encryption */
! 47: void
! 48: none_setkey(CipherContext *cc, const u_char *key, u_int keylen)
! 49: {
! 50: }
! 51: void
! 52: none_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
! 53: {
! 54: }
! 55: void
! 56: none_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
! 57: {
! 58: memcpy(dest, src, len);
! 59: }
! 60:
! 61: /* DES */
! 62: void
! 63: des_ssh1_setkey(CipherContext *cc, const u_char *key, u_int keylen)
! 64: {
! 65: static int dowarn = 1;
! 66: if (dowarn) {
! 67: error("Warning: use of DES is strongly discouraged "
! 68: "due to cryptographic weaknesses");
! 69: dowarn = 0;
! 70: }
! 71: des_set_key((void *)key, cc->u.des.key);
! 72: }
! 73: void
! 74: des_ssh1_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
! 75: {
! 76: memset(cc->u.des.iv, 0, sizeof(cc->u.des.iv));
! 77: }
! 78: void
! 79: des_ssh1_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
! 80: {
! 81: des_ncbc_encrypt(src, dest, len, cc->u.des.key, &cc->u.des.iv,
! 82: DES_ENCRYPT);
! 83: }
! 84: void
! 85: des_ssh1_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
! 86: {
! 87: des_ncbc_encrypt(src, dest, len, cc->u.des.key, &cc->u.des.iv,
! 88: DES_DECRYPT);
! 89: }
! 90:
! 91: /* 3DES */
! 92: void
! 93: des3_setkey(CipherContext *cc, const u_char *key, u_int keylen)
! 94: {
! 95: des_set_key((void *) key, cc->u.des3.key1);
! 96: des_set_key((void *) (key+8), cc->u.des3.key2);
! 97: des_set_key((void *) (key+16), cc->u.des3.key3);
! 98: }
! 99: void
! 100: des3_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
! 101: {
! 102: memset(cc->u.des3.iv2, 0, sizeof(cc->u.des3.iv2));
! 103: memset(cc->u.des3.iv3, 0, sizeof(cc->u.des3.iv3));
! 104: if (iv == NULL)
! 105: return;
! 106: memcpy(cc->u.des3.iv3, (char *)iv, 8);
! 107: }
! 108: void
! 109: des3_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
! 110: {
! 111: des_ede3_cbc_encrypt(src, dest, len,
! 112: cc->u.des3.key1, cc->u.des3.key2, cc->u.des3.key3,
! 113: &cc->u.des3.iv3, DES_ENCRYPT);
! 114: }
! 115: void
! 116: des3_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
! 117: {
! 118: des_ede3_cbc_encrypt(src, dest, len,
! 119: cc->u.des3.key1, cc->u.des3.key2, cc->u.des3.key3,
! 120: &cc->u.des3.iv3, DES_DECRYPT);
! 121: }
! 122:
1.1 deraadt 123: /*
1.24 markus 124: * This is used by SSH1:
125: *
1.23 deraadt 126: * What kind of triple DES are these 2 routines?
1.1 deraadt 127: *
128: * Why is there a redundant initialization vector?
129: *
130: * If only iv3 was used, then, this would till effect have been
131: * outer-cbc. However, there is also a private iv1 == iv2 which
132: * perhaps makes differential analysis easier. On the other hand, the
133: * private iv1 probably makes the CRC-32 attack ineffective. This is a
134: * result of that there is no longer any known iv1 to use when
135: * choosing the X block.
136: */
137: void
1.26.2.3! jason 138: des3_ssh1_setkey(CipherContext *cc, const u_char *key, u_int keylen)
! 139: {
! 140: des_set_key((void *) key, cc->u.des3.key1);
! 141: des_set_key((void *) (key+8), cc->u.des3.key2);
! 142: if (keylen <= 16)
! 143: des_set_key((void *) key, cc->u.des3.key3);
! 144: else
! 145: des_set_key((void *) (key+16), cc->u.des3.key3);
! 146: }
! 147: void
! 148: des3_ssh1_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
! 149: u_int len)
1.1 deraadt 150: {
1.16 markus 151: des_cblock iv1;
1.26.2.3! jason 152: des_cblock *iv2 = &cc->u.des3.iv2;
! 153: des_cblock *iv3 = &cc->u.des3.iv3;
1.1 deraadt 154:
1.16 markus 155: memcpy(&iv1, iv2, 8);
1.1 deraadt 156:
1.26.2.3! jason 157: des_cbc_encrypt(src, dest, len, cc->u.des3.key1, &iv1, DES_ENCRYPT);
1.16 markus 158: memcpy(&iv1, dest + len - 8, 8);
1.1 deraadt 159:
1.26.2.3! jason 160: des_cbc_encrypt(dest, dest, len, cc->u.des3.key2, iv2, DES_DECRYPT);
1.16 markus 161: memcpy(iv2, &iv1, 8); /* Note how iv1 == iv2 on entry and exit. */
1.1 deraadt 162:
1.26.2.3! jason 163: des_cbc_encrypt(dest, dest, len, cc->u.des3.key3, iv3, DES_ENCRYPT);
1.16 markus 164: memcpy(iv3, dest + len - 8, 8);
1.1 deraadt 165: }
166: void
1.26.2.3! jason 167: des3_ssh1_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
! 168: u_int len)
1.1 deraadt 169: {
1.16 markus 170: des_cblock iv1;
1.26.2.3! jason 171: des_cblock *iv2 = &cc->u.des3.iv2;
! 172: des_cblock *iv3 = &cc->u.des3.iv3;
1.1 deraadt 173:
1.16 markus 174: memcpy(&iv1, iv2, 8);
1.1 deraadt 175:
1.26.2.3! jason 176: des_cbc_encrypt(src, dest, len, cc->u.des3.key3, iv3, DES_DECRYPT);
1.16 markus 177: memcpy(iv3, src + len - 8, 8);
1.1 deraadt 178:
1.26.2.3! jason 179: des_cbc_encrypt(dest, dest, len, cc->u.des3.key2, iv2, DES_ENCRYPT);
1.16 markus 180: memcpy(iv2, dest + len - 8, 8);
1.1 deraadt 181:
1.26.2.3! jason 182: des_cbc_encrypt(dest, dest, len, cc->u.des3.key1, &iv1, DES_DECRYPT);
1.16 markus 183: /* memcpy(&iv1, iv2, 8); */
184: /* Note how iv1 == iv2 on entry and exit. */
1.1 deraadt 185: }
186:
1.26.2.3! jason 187: /* Blowfish */
! 188: void
! 189: blowfish_setkey(CipherContext *cc, const u_char *key, u_int keylen)
! 190: {
! 191: BF_set_key(&cc->u.bf.key, keylen, (unsigned char *)key);
! 192: }
! 193: void
! 194: blowfish_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
! 195: {
! 196: if (iv == NULL)
! 197: memset(cc->u.bf.iv, 0, 8);
! 198: else
! 199: memcpy(cc->u.bf.iv, (char *)iv, 8);
! 200: }
! 201: void
! 202: blowfish_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
! 203: u_int len)
! 204: {
! 205: BF_cbc_encrypt((void *)src, dest, len, &cc->u.bf.key, cc->u.bf.iv,
! 206: BF_ENCRYPT);
! 207: }
! 208: void
! 209: blowfish_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
! 210: u_int len)
! 211: {
! 212: BF_cbc_encrypt((void *)src, dest, len, &cc->u.bf.key, cc->u.bf.iv,
! 213: BF_DECRYPT);
! 214: }
! 215:
1.1 deraadt 216: /*
1.24 markus 217: * SSH1 uses a variation on Blowfish, all bytes must be swapped before
1.1 deraadt 218: * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
219: */
1.16 markus 220: static void
1.26.2.3! jason 221: swap_bytes(const unsigned char *src, unsigned char *dst, int n)
1.1 deraadt 222: {
1.26.2.3! jason 223: char c[4];
! 224:
! 225: /* Process 4 bytes every lap. */
! 226: for (n = n / 4; n > 0; n--) {
! 227: c[3] = *src++;
! 228: c[2] = *src++;
! 229: c[1] = *src++;
! 230: c[0] = *src++;
! 231:
! 232: *dst++ = c[0];
! 233: *dst++ = c[1];
! 234: *dst++ = c[2];
! 235: *dst++ = c[3];
1.16 markus 236: }
1.1 deraadt 237: }
238:
1.26.2.3! jason 239: void
! 240: blowfish_ssh1_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
! 241: u_int len)
1.4 provos 242: {
1.26.2.3! jason 243: swap_bytes(src, dest, len);
! 244: BF_cbc_encrypt((void *)dest, dest, len, &cc->u.bf.key, cc->u.bf.iv,
! 245: BF_ENCRYPT);
! 246: swap_bytes(dest, dest, len);
! 247: }
! 248: void
! 249: blowfish_ssh1_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
! 250: u_int len)
! 251: {
! 252: swap_bytes(src, dest, len);
! 253: BF_cbc_encrypt((void *)dest, dest, len, &cc->u.bf.key, cc->u.bf.iv,
! 254: BF_DECRYPT);
! 255: swap_bytes(dest, dest, len);
! 256: }
1.1 deraadt 257:
1.26.2.3! jason 258: /* alleged rc4 */
! 259: void
! 260: arcfour_setkey(CipherContext *cc, const u_char *key, u_int keylen)
! 261: {
! 262: RC4_set_key(&cc->u.rc4, keylen, (u_char *)key);
! 263: }
! 264: void
! 265: arcfour_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
! 266: {
! 267: RC4(&cc->u.rc4, len, (u_char *)src, dest);
! 268: }
1.1 deraadt 269:
1.26.2.3! jason 270: /* CAST */
! 271: void
! 272: cast_setkey(CipherContext *cc, const u_char *key, u_int keylen)
1.1 deraadt 273: {
1.26.2.3! jason 274: CAST_set_key(&cc->u.cast.key, keylen, (unsigned char *) key);
1.22 markus 275: }
1.26.2.3! jason 276: void
! 277: cast_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
1.22 markus 278: {
1.26.2.3! jason 279: if (iv == NULL)
! 280: fatal("no IV for %s.", cc->cipher->name);
! 281: memcpy(cc->u.cast.iv, (char *)iv, 8);
1.1 deraadt 282: }
1.26.2.3! jason 283: void
! 284: cast_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
! 285: {
! 286: CAST_cbc_encrypt(src, dest, len, &cc->u.cast.key, cc->u.cast.iv,
! 287: CAST_ENCRYPT);
! 288: }
! 289: void
! 290: cast_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
! 291: {
! 292: CAST_cbc_encrypt(src, dest, len, &cc->u.cast.key, cc->u.cast.iv,
! 293: CAST_DECRYPT);
! 294: }
! 295:
! 296: /* RIJNDAEL */
! 297:
! 298: #define RIJNDAEL_BLOCKSIZE 16
! 299: void
! 300: rijndael_setkey(CipherContext *cc, const u_char *key, u_int keylen)
! 301: {
! 302: rijndael_set_key(&cc->u.rijndael.enc, (u4byte *)key, 8*keylen, 1);
! 303: rijndael_set_key(&cc->u.rijndael.dec, (u4byte *)key, 8*keylen, 0);
! 304: }
! 305: void
! 306: rijndael_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
1.22 markus 307: {
1.26.2.3! jason 308: if (iv == NULL)
! 309: fatal("no IV for %s.", cc->cipher->name);
! 310: memcpy((u_char *)cc->u.rijndael.iv, iv, RIJNDAEL_BLOCKSIZE);
1.22 markus 311: }
1.26.2.3! jason 312: void
! 313: rijndael_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
! 314: u_int len)
! 315: {
! 316: rijndael_ctx *ctx = &cc->u.rijndael.enc;
! 317: u4byte *iv = cc->u.rijndael.iv;
! 318: u4byte in[4];
! 319: u4byte *cprev, *cnow, *plain;
! 320: int i, blocks = len / RIJNDAEL_BLOCKSIZE;
! 321: if (len == 0)
! 322: return;
! 323: if (len % RIJNDAEL_BLOCKSIZE)
! 324: fatal("rijndael_cbc_encrypt: bad len %d", len);
! 325: cnow = (u4byte*) dest;
! 326: plain = (u4byte*) src;
! 327: cprev = iv;
! 328: for(i = 0; i < blocks; i++, plain+=4, cnow+=4) {
! 329: in[0] = plain[0] ^ cprev[0];
! 330: in[1] = plain[1] ^ cprev[1];
! 331: in[2] = plain[2] ^ cprev[2];
! 332: in[3] = plain[3] ^ cprev[3];
! 333: rijndael_encrypt(ctx, in, cnow);
! 334: cprev = cnow;
! 335: }
! 336: memcpy(iv, cprev, RIJNDAEL_BLOCKSIZE);
! 337: }
! 338:
! 339: void
! 340: rijndael_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
! 341: u_int len)
! 342: {
! 343: rijndael_ctx *ctx = &cc->u.rijndael.dec;
! 344: u4byte *iv = cc->u.rijndael.iv;
! 345: u4byte ivsaved[4];
! 346: u4byte *cnow = (u4byte*) (src+len-RIJNDAEL_BLOCKSIZE);
! 347: u4byte *plain = (u4byte*) (dest+len-RIJNDAEL_BLOCKSIZE);
! 348: u4byte *ivp;
! 349: int i, blocks = len / RIJNDAEL_BLOCKSIZE;
! 350: if (len == 0)
! 351: return;
! 352: if (len % RIJNDAEL_BLOCKSIZE)
! 353: fatal("rijndael_cbc_decrypt: bad len %d", len);
! 354: memcpy(ivsaved, cnow, RIJNDAEL_BLOCKSIZE);
! 355: for(i = blocks; i > 0; i--, cnow-=4, plain-=4) {
! 356: rijndael_decrypt(ctx, cnow, plain);
! 357: ivp = (i == 1) ? iv : cnow-4;
! 358: plain[0] ^= ivp[0];
! 359: plain[1] ^= ivp[1];
! 360: plain[2] ^= ivp[2];
! 361: plain[3] ^= ivp[3];
! 362: }
! 363: memcpy(iv, ivsaved, RIJNDAEL_BLOCKSIZE);
! 364: }
! 365:
! 366: Cipher ciphers[] = {
! 367: { "none",
! 368: SSH_CIPHER_NONE, 8, 0,
! 369: none_setkey, none_setiv,
! 370: none_crypt, none_crypt },
! 371: { "des",
! 372: SSH_CIPHER_DES, 8, 8,
! 373: des_ssh1_setkey, des_ssh1_setiv,
! 374: des_ssh1_encrypt, des_ssh1_decrypt },
! 375: { "3des",
! 376: SSH_CIPHER_3DES, 8, 16,
! 377: des3_ssh1_setkey, des3_setiv,
! 378: des3_ssh1_encrypt, des3_ssh1_decrypt },
! 379: { "blowfish",
! 380: SSH_CIPHER_BLOWFISH, 8, 16,
! 381: blowfish_setkey, blowfish_setiv,
! 382: blowfish_ssh1_encrypt, blowfish_ssh1_decrypt },
! 383:
! 384: { "3des-cbc",
! 385: SSH_CIPHER_SSH2, 8, 24,
! 386: des3_setkey, des3_setiv,
! 387: des3_cbc_encrypt, des3_cbc_decrypt },
! 388: { "blowfish-cbc",
! 389: SSH_CIPHER_SSH2, 8, 16,
! 390: blowfish_setkey, blowfish_setiv,
! 391: blowfish_cbc_encrypt, blowfish_cbc_decrypt },
! 392: { "cast128-cbc",
! 393: SSH_CIPHER_SSH2, 8, 16,
! 394: cast_setkey, cast_setiv,
! 395: cast_cbc_encrypt, cast_cbc_decrypt },
! 396: { "arcfour",
! 397: SSH_CIPHER_SSH2, 8, 16,
! 398: arcfour_setkey, none_setiv,
! 399: arcfour_crypt, arcfour_crypt },
! 400: { "aes128-cbc",
! 401: SSH_CIPHER_SSH2, 16, 16,
! 402: rijndael_setkey, rijndael_setiv,
! 403: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
! 404: { "aes192-cbc",
! 405: SSH_CIPHER_SSH2, 16, 24,
! 406: rijndael_setkey, rijndael_setiv,
! 407: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
! 408: { "aes256-cbc",
! 409: SSH_CIPHER_SSH2, 16, 32,
! 410: rijndael_setkey, rijndael_setiv,
! 411: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
! 412: { "rijndael128-cbc",
! 413: SSH_CIPHER_SSH2, 16, 16,
! 414: rijndael_setkey, rijndael_setiv,
! 415: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
! 416: { "rijndael192-cbc",
! 417: SSH_CIPHER_SSH2, 16, 24,
! 418: rijndael_setkey, rijndael_setiv,
! 419: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
! 420: { "rijndael256-cbc",
! 421: SSH_CIPHER_SSH2, 16, 32,
! 422: rijndael_setkey, rijndael_setiv,
! 423: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
! 424: { "rijndael-cbc@lysator.liu.se",
! 425: SSH_CIPHER_SSH2, 16, 32,
! 426: rijndael_setkey, rijndael_setiv,
! 427: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
! 428: { NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL, NULL, NULL, NULL }
! 429: };
1.1 deraadt 430:
1.26.2.3! jason 431: /*--*/
1.1 deraadt 432:
1.26.2.3! jason 433: unsigned int
! 434: cipher_mask_ssh1(int client)
1.1 deraadt 435: {
1.26.2.3! jason 436: unsigned int mask = 0;
! 437: mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */
! 438: mask |= 1 << SSH_CIPHER_BLOWFISH;
! 439: if (client) {
! 440: mask |= 1 << SSH_CIPHER_DES;
! 441: }
! 442: return mask;
1.1 deraadt 443: }
444:
1.26.2.3! jason 445: Cipher *
! 446: cipher_by_name(const char *name)
! 447: {
! 448: Cipher *c;
! 449: for (c = ciphers; c->name != NULL; c++)
! 450: if (strcasecmp(c->name, name) == 0)
! 451: return c;
! 452: return NULL;
! 453: }
! 454:
! 455: Cipher *
! 456: cipher_by_number(int id)
! 457: {
! 458: Cipher *c;
! 459: for (c = ciphers; c->name != NULL; c++)
! 460: if (c->number == id)
! 461: return c;
! 462: return NULL;
! 463: }
1.24 markus 464:
465: #define CIPHER_SEP ","
466: int
467: ciphers_valid(const char *names)
468: {
1.26.2.3! jason 469: Cipher *c;
1.26.2.2 jason 470: char *ciphers, *cp;
1.24 markus 471: char *p;
472:
1.26.2.1 jason 473: if (names == NULL || strcmp(names, "") == 0)
1.24 markus 474: return 0;
1.26.2.2 jason 475: ciphers = cp = xstrdup(names);
1.26.2.3! jason 476: for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
1.26.2.2 jason 477: (p = strsep(&cp, CIPHER_SEP))) {
1.26.2.3! jason 478: c = cipher_by_name(p);
! 479: if (c == NULL || c->number != SSH_CIPHER_SSH2) {
! 480: debug("bad cipher %s [%s]", p, names);
1.24 markus 481: xfree(ciphers);
482: return 0;
1.26.2.3! jason 483: } else {
! 484: debug3("cipher ok: %s [%s]", p, names);
1.24 markus 485: }
486: }
1.26.2.3! jason 487: debug3("ciphers ok: [%s]", names);
1.24 markus 488: xfree(ciphers);
489: return 1;
490: }
491:
1.18 markus 492: /*
493: * Parses the name of the cipher. Returns the number of the corresponding
494: * cipher, or -1 on error.
495: */
1.1 deraadt 496:
1.4 provos 497: int
498: cipher_number(const char *name)
1.1 deraadt 499: {
1.26.2.3! jason 500: Cipher *c;
1.26.2.1 jason 501: if (name == NULL)
502: return -1;
1.26.2.3! jason 503: c = cipher_by_name(name);
! 504: return (c==NULL) ? -1 : c->number;
1.1 deraadt 505: }
506:
1.26.2.3! jason 507: char *
! 508: cipher_name(int id)
1.1 deraadt 509: {
1.26.2.3! jason 510: Cipher *c = cipher_by_number(id);
! 511: return (c==NULL) ? "<unknown>" : c->name;
1.1 deraadt 512: }
513:
1.26 markus 514: void
1.26.2.3! jason 515: cipher_init(CipherContext *cc, Cipher *cipher,
! 516: const u_char *key, u_int keylen, const u_char *iv, u_int ivlen)
1.16 markus 517: {
1.26.2.3! jason 518: if (keylen < cipher->key_len)
! 519: fatal("cipher_init: key length %d is insufficient for %s.",
! 520: keylen, cipher->name);
! 521: if (iv != NULL && ivlen < cipher->block_size)
! 522: fatal("cipher_init: iv length %d is insufficient for %s.",
! 523: ivlen, cipher->name);
! 524: cc->cipher = cipher;
! 525: cipher->setkey(cc, key, keylen);
! 526: cipher->setiv(cc, iv, ivlen);
1.1 deraadt 527: }
1.21 markus 528:
1.26 markus 529: void
1.26.2.3! jason 530: cipher_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
! 531: {
! 532: if (len % cc->cipher->block_size)
! 533: fatal("cipher_encrypt: bad plaintext length %d", len);
! 534: cc->cipher->encrypt(cc, dest, src, len);
1.21 markus 535: }
536:
1.26 markus 537: void
1.26.2.3! jason 538: cipher_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
1.16 markus 539: {
1.26.2.3! jason 540: if (len % cc->cipher->block_size)
! 541: fatal("cipher_decrypt: bad ciphertext length %d", len);
! 542: cc->cipher->decrypt(cc, dest, src, len);
1.16 markus 543: }
1.1 deraadt 544:
1.26.2.3! jason 545: /*
! 546: * Selects the cipher, and keys if by computing the MD5 checksum of the
! 547: * passphrase and using the resulting 16 bytes as the key.
! 548: */
1.1 deraadt 549:
1.26 markus 550: void
1.26.2.3! jason 551: cipher_set_key_string(CipherContext *cc, Cipher *cipher,
! 552: const char *passphrase)
1.16 markus 553: {
1.26.2.3! jason 554: MD5_CTX md;
! 555: unsigned char digest[16];
! 556:
! 557: MD5_Init(&md);
! 558: MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase));
! 559: MD5_Final(digest, &md);
1.16 markus 560:
1.26.2.3! jason 561: cipher_init(cc, cipher, digest, 16, NULL, 0);
1.16 markus 562:
1.26.2.3! jason 563: memset(digest, 0, sizeof(digest));
! 564: memset(&md, 0, sizeof(md));
1.1 deraadt 565: }
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