Annotation of src/usr.bin/ssh/cipher.c, Revision 1.39
1.1 deraadt 1: /*
1.30 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: *
1.30 deraadt 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".
1.26 markus 11: *
12: *
1.30 deraadt 13: * Copyright (c) 1999 Niels Provos. All rights reserved.
14: * Copyright (c) 1999,2000 Markus Friedl. All rights reserved.
1.26 markus 15: *
1.30 deraadt 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.
1.26 markus 24: *
1.30 deraadt 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"
1.39 ! markus 38: RCSID("$OpenBSD: cipher.c,v 1.38 2000/11/29 20:39:17 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:
1.32 markus 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: {
1.34 markus 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: }
1.32 markus 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
1.32 markus 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;
1.32 markus 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:
1.38 markus 157: des_ncbc_encrypt(src, dest, len, cc->u.des3.key1, &iv1, DES_ENCRYPT);
158: des_ncbc_encrypt(dest, dest, len, cc->u.des3.key2, iv2, DES_DECRYPT);
159: des_ncbc_encrypt(dest, dest, len, cc->u.des3.key3, iv3, DES_ENCRYPT);
1.1 deraadt 160: }
161: void
1.32 markus 162: des3_ssh1_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
163: u_int len)
1.1 deraadt 164: {
1.16 markus 165: des_cblock iv1;
1.32 markus 166: des_cblock *iv2 = &cc->u.des3.iv2;
167: des_cblock *iv3 = &cc->u.des3.iv3;
1.1 deraadt 168:
1.16 markus 169: memcpy(&iv1, iv2, 8);
1.1 deraadt 170:
1.38 markus 171: des_ncbc_encrypt(src, dest, len, cc->u.des3.key3, iv3, DES_DECRYPT);
172: des_ncbc_encrypt(dest, dest, len, cc->u.des3.key2, iv2, DES_ENCRYPT);
173: des_ncbc_encrypt(dest, dest, len, cc->u.des3.key1, &iv1, DES_DECRYPT);
1.1 deraadt 174: }
175:
1.32 markus 176: /* Blowfish */
177: void
178: blowfish_setkey(CipherContext *cc, const u_char *key, u_int keylen)
179: {
180: BF_set_key(&cc->u.bf.key, keylen, (unsigned char *)key);
181: }
182: void
183: blowfish_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
184: {
185: if (iv == NULL)
186: memset(cc->u.bf.iv, 0, 8);
187: else
188: memcpy(cc->u.bf.iv, (char *)iv, 8);
189: }
190: void
191: blowfish_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
192: u_int len)
193: {
194: BF_cbc_encrypt((void *)src, dest, len, &cc->u.bf.key, cc->u.bf.iv,
195: BF_ENCRYPT);
196: }
197: void
198: blowfish_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
199: u_int len)
200: {
201: BF_cbc_encrypt((void *)src, dest, len, &cc->u.bf.key, cc->u.bf.iv,
202: BF_DECRYPT);
203: }
204:
1.1 deraadt 205: /*
1.24 markus 206: * SSH1 uses a variation on Blowfish, all bytes must be swapped before
1.1 deraadt 207: * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
208: */
1.16 markus 209: static void
1.37 markus 210: swap_bytes(const unsigned char *src, unsigned char *dst, int n)
1.1 deraadt 211: {
1.37 markus 212: char c[4];
213:
214: /* Process 4 bytes every lap. */
215: for (n = n / 4; n > 0; n--) {
216: c[3] = *src++;
217: c[2] = *src++;
218: c[1] = *src++;
219: c[0] = *src++;
220:
221: *dst++ = c[0];
222: *dst++ = c[1];
223: *dst++ = c[2];
224: *dst++ = c[3];
1.16 markus 225: }
1.1 deraadt 226: }
227:
1.32 markus 228: void
229: blowfish_ssh1_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
230: u_int len)
231: {
232: swap_bytes(src, dest, len);
233: BF_cbc_encrypt((void *)dest, dest, len, &cc->u.bf.key, cc->u.bf.iv,
234: BF_ENCRYPT);
235: swap_bytes(dest, dest, len);
236: }
237: void
238: blowfish_ssh1_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
239: u_int len)
1.4 provos 240: {
1.32 markus 241: swap_bytes(src, dest, len);
242: BF_cbc_encrypt((void *)dest, dest, len, &cc->u.bf.key, cc->u.bf.iv,
243: BF_DECRYPT);
244: swap_bytes(dest, dest, len);
245: }
1.1 deraadt 246:
1.32 markus 247: /* alleged rc4 */
248: void
249: arcfour_setkey(CipherContext *cc, const u_char *key, u_int keylen)
250: {
251: RC4_set_key(&cc->u.rc4, keylen, (u_char *)key);
252: }
253: void
254: arcfour_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
255: {
256: RC4(&cc->u.rc4, len, (u_char *)src, dest);
257: }
1.1 deraadt 258:
1.32 markus 259: /* CAST */
260: void
261: cast_setkey(CipherContext *cc, const u_char *key, u_int keylen)
262: {
263: CAST_set_key(&cc->u.cast.key, keylen, (unsigned char *) key);
264: }
265: void
266: cast_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
1.1 deraadt 267: {
1.32 markus 268: if (iv == NULL)
269: fatal("no IV for %s.", cc->cipher->name);
270: memcpy(cc->u.cast.iv, (char *)iv, 8);
1.22 markus 271: }
1.32 markus 272: void
273: cast_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
1.22 markus 274: {
1.32 markus 275: CAST_cbc_encrypt(src, dest, len, &cc->u.cast.key, cc->u.cast.iv,
276: CAST_ENCRYPT);
1.1 deraadt 277: }
1.32 markus 278: void
279: cast_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
1.22 markus 280: {
1.32 markus 281: CAST_cbc_encrypt(src, dest, len, &cc->u.cast.key, cc->u.cast.iv,
282: CAST_DECRYPT);
1.22 markus 283: }
1.1 deraadt 284:
1.35 markus 285: /* RIJNDAEL */
286:
287: #define RIJNDAEL_BLOCKSIZE 16
1.39 ! markus 288:
1.35 markus 289: void
290: rijndael_setkey(CipherContext *cc, const u_char *key, u_int keylen)
291: {
1.39 ! markus 292: if (rijndael_makekey(&cc->u.rijndael.enc, RIJNDAEL_ENCRYPT,
! 293: 8*keylen, (char *)key) == -1)
! 294: fatal("rijndael_setkey: RIJNDAEL_ENCRYPT");
! 295: if (rijndael_makekey(&cc->u.rijndael.dec, RIJNDAEL_DECRYPT,
! 296: 8*keylen, (char *)key) == -1)
! 297: fatal("rijndael_setkey: RIJNDAEL_DECRYPT");
1.35 markus 298: }
299: void
300: rijndael_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
301: {
1.39 ! markus 302: if (iv == NULL || ivlen != RIJNDAEL_BLOCKSIZE)
! 303: fatal("bad/no IV for %s.", cc->cipher->name);
! 304: memcpy(cc->u.rijndael.iv, iv, RIJNDAEL_BLOCKSIZE);
1.35 markus 305: }
1.39 ! markus 306:
1.35 markus 307: void
308: rijndael_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
309: u_int len)
310: {
1.39 ! markus 311: rijndael_key *ctx = &cc->u.rijndael.enc;
! 312: u_char *iv = cc->u.rijndael.iv;
! 313: u_char in[RIJNDAEL_BLOCKSIZE];
! 314: u_char *cprev, *cnow, *plain;
! 315: int i, j, blocks = len / RIJNDAEL_BLOCKSIZE;
1.35 markus 316: if (len == 0)
317: return;
318: if (len % RIJNDAEL_BLOCKSIZE)
319: fatal("rijndael_cbc_encrypt: bad len %d", len);
1.39 ! markus 320: cnow = dest;
! 321: plain = (u_char *) src;
1.35 markus 322: cprev = iv;
1.39 ! markus 323: for(i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE,
! 324: cnow+=RIJNDAEL_BLOCKSIZE) {
! 325: for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++)
! 326: in[j] = plain[j] ^ cprev[j];
1.35 markus 327: rijndael_encrypt(ctx, in, cnow);
328: cprev = cnow;
329: }
330: memcpy(iv, cprev, RIJNDAEL_BLOCKSIZE);
331: }
332:
333: void
334: rijndael_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
335: u_int len)
336: {
1.39 ! markus 337: rijndael_key *ctx = &cc->u.rijndael.dec;
! 338: u_char *iv = cc->u.rijndael.iv;
! 339: u_char ivsaved[RIJNDAEL_BLOCKSIZE];
! 340: u_char *cnow = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE);
! 341: u_char *plain = dest+len-RIJNDAEL_BLOCKSIZE;
! 342: u_char *ivp;
! 343: int i, j, blocks = len / RIJNDAEL_BLOCKSIZE;
1.35 markus 344: if (len == 0)
345: return;
346: if (len % RIJNDAEL_BLOCKSIZE)
347: fatal("rijndael_cbc_decrypt: bad len %d", len);
348: memcpy(ivsaved, cnow, RIJNDAEL_BLOCKSIZE);
1.39 ! markus 349: for(i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE,
! 350: plain-=RIJNDAEL_BLOCKSIZE) {
1.35 markus 351: rijndael_decrypt(ctx, cnow, plain);
1.39 ! markus 352: //rijndael_decrypt(cnow, plain, ctx->keySched, ctx->ROUNDS);
! 353: ivp = (i == 1) ? iv : cnow-RIJNDAEL_BLOCKSIZE;
! 354: for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++)
! 355: plain[j] ^= ivp[j];
1.35 markus 356: }
357: memcpy(iv, ivsaved, RIJNDAEL_BLOCKSIZE);
358: }
1.32 markus 359:
360: Cipher ciphers[] = {
361: { "none",
362: SSH_CIPHER_NONE, 8, 0,
363: none_setkey, none_setiv,
364: none_crypt, none_crypt },
1.34 markus 365: { "des",
366: SSH_CIPHER_DES, 8, 8,
367: des_ssh1_setkey, des_ssh1_setiv,
368: des_ssh1_encrypt, des_ssh1_decrypt },
1.32 markus 369: { "3des",
370: SSH_CIPHER_3DES, 8, 16,
371: des3_ssh1_setkey, des3_setiv,
372: des3_ssh1_encrypt, des3_ssh1_decrypt },
373: { "blowfish",
374: SSH_CIPHER_BLOWFISH, 8, 16,
375: blowfish_setkey, blowfish_setiv,
376: blowfish_ssh1_encrypt, blowfish_ssh1_decrypt },
377:
378: { "3des-cbc",
379: SSH_CIPHER_SSH2, 8, 24,
380: des3_setkey, des3_setiv,
381: des3_cbc_encrypt, des3_cbc_decrypt },
382: { "blowfish-cbc",
383: SSH_CIPHER_SSH2, 8, 16,
384: blowfish_setkey, blowfish_setiv,
385: blowfish_cbc_encrypt, blowfish_cbc_decrypt },
386: { "cast128-cbc",
387: SSH_CIPHER_SSH2, 8, 16,
388: cast_setkey, cast_setiv,
389: cast_cbc_encrypt, cast_cbc_decrypt },
390: { "arcfour",
391: SSH_CIPHER_SSH2, 8, 16,
392: arcfour_setkey, none_setiv,
393: arcfour_crypt, arcfour_crypt },
1.35 markus 394: { "aes128-cbc",
395: SSH_CIPHER_SSH2, 16, 16,
396: rijndael_setkey, rijndael_setiv,
397: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
398: { "aes192-cbc",
399: SSH_CIPHER_SSH2, 16, 24,
400: rijndael_setkey, rijndael_setiv,
401: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
402: { "aes256-cbc",
403: SSH_CIPHER_SSH2, 16, 32,
404: rijndael_setkey, rijndael_setiv,
405: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
406: { "rijndael128-cbc",
407: SSH_CIPHER_SSH2, 16, 16,
408: rijndael_setkey, rijndael_setiv,
409: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
410: { "rijndael192-cbc",
411: SSH_CIPHER_SSH2, 16, 24,
412: rijndael_setkey, rijndael_setiv,
413: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
414: { "rijndael256-cbc",
415: SSH_CIPHER_SSH2, 16, 32,
416: rijndael_setkey, rijndael_setiv,
417: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
418: { "rijndael-cbc@lysator.liu.se",
419: SSH_CIPHER_SSH2, 16, 32,
420: rijndael_setkey, rijndael_setiv,
421: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
1.32 markus 422: { NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL, NULL, NULL, NULL }
423: };
424:
425: /*--*/
1.1 deraadt 426:
1.32 markus 427: unsigned int
1.34 markus 428: cipher_mask_ssh1(int client)
1.1 deraadt 429: {
1.32 markus 430: unsigned int mask = 0;
1.34 markus 431: mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */
432: mask |= 1 << SSH_CIPHER_BLOWFISH;
433: if (client) {
434: mask |= 1 << SSH_CIPHER_DES;
1.32 markus 435: }
436: return mask;
1.1 deraadt 437: }
438:
1.32 markus 439: Cipher *
440: cipher_by_name(const char *name)
441: {
442: Cipher *c;
443: for (c = ciphers; c->name != NULL; c++)
444: if (strcasecmp(c->name, name) == 0)
445: return c;
446: return NULL;
447: }
448:
449: Cipher *
450: cipher_by_number(int id)
451: {
452: Cipher *c;
453: for (c = ciphers; c->name != NULL; c++)
454: if (c->number == id)
455: return c;
456: return NULL;
457: }
1.24 markus 458:
459: #define CIPHER_SEP ","
460: int
461: ciphers_valid(const char *names)
462: {
1.32 markus 463: Cipher *c;
1.29 ho 464: char *ciphers, *cp;
1.24 markus 465: char *p;
466:
1.27 markus 467: if (names == NULL || strcmp(names, "") == 0)
1.24 markus 468: return 0;
1.29 ho 469: ciphers = cp = xstrdup(names);
1.32 markus 470: for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
1.29 ho 471: (p = strsep(&cp, CIPHER_SEP))) {
1.32 markus 472: c = cipher_by_name(p);
473: if (c == NULL || c->number != SSH_CIPHER_SSH2) {
474: debug("bad cipher %s [%s]", p, names);
1.24 markus 475: xfree(ciphers);
476: return 0;
1.32 markus 477: } else {
1.36 markus 478: debug3("cipher ok: %s [%s]", p, names);
1.24 markus 479: }
480: }
1.36 markus 481: debug3("ciphers ok: [%s]", names);
1.24 markus 482: xfree(ciphers);
483: return 1;
484: }
485:
1.18 markus 486: /*
487: * Parses the name of the cipher. Returns the number of the corresponding
488: * cipher, or -1 on error.
489: */
1.1 deraadt 490:
1.4 provos 491: int
492: cipher_number(const char *name)
1.1 deraadt 493: {
1.32 markus 494: Cipher *c;
1.27 markus 495: if (name == NULL)
496: return -1;
1.32 markus 497: c = cipher_by_name(name);
498: return (c==NULL) ? -1 : c->number;
1.1 deraadt 499: }
500:
1.32 markus 501: char *
502: cipher_name(int id)
1.1 deraadt 503: {
1.32 markus 504: Cipher *c = cipher_by_number(id);
505: return (c==NULL) ? "<unknown>" : c->name;
1.1 deraadt 506: }
507:
1.26 markus 508: void
1.32 markus 509: cipher_init(CipherContext *cc, Cipher *cipher,
510: const u_char *key, u_int keylen, const u_char *iv, u_int ivlen)
1.16 markus 511: {
1.32 markus 512: if (keylen < cipher->key_len)
513: fatal("cipher_init: key length %d is insufficient for %s.",
514: keylen, cipher->name);
515: if (iv != NULL && ivlen < cipher->block_size)
516: fatal("cipher_init: iv length %d is insufficient for %s.",
517: ivlen, cipher->name);
518: cc->cipher = cipher;
519: cipher->setkey(cc, key, keylen);
520: cipher->setiv(cc, iv, ivlen);
1.1 deraadt 521: }
1.21 markus 522:
1.26 markus 523: void
1.32 markus 524: cipher_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
525: {
526: if (len % cc->cipher->block_size)
527: fatal("cipher_encrypt: bad plaintext length %d", len);
528: cc->cipher->encrypt(cc, dest, src, len);
1.21 markus 529: }
530:
1.26 markus 531: void
1.32 markus 532: cipher_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
1.16 markus 533: {
1.32 markus 534: if (len % cc->cipher->block_size)
535: fatal("cipher_decrypt: bad ciphertext length %d", len);
536: cc->cipher->decrypt(cc, dest, src, len);
1.16 markus 537: }
1.1 deraadt 538:
1.32 markus 539: /*
540: * Selects the cipher, and keys if by computing the MD5 checksum of the
541: * passphrase and using the resulting 16 bytes as the key.
542: */
1.1 deraadt 543:
1.26 markus 544: void
1.32 markus 545: cipher_set_key_string(CipherContext *cc, Cipher *cipher,
546: const char *passphrase)
1.16 markus 547: {
1.32 markus 548: MD5_CTX md;
549: unsigned char digest[16];
550:
551: MD5_Init(&md);
552: MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase));
553: MD5_Final(digest, &md);
1.16 markus 554:
1.32 markus 555: cipher_init(cc, cipher, digest, 16, NULL, 0);
1.16 markus 556:
1.32 markus 557: memset(digest, 0, sizeof(digest));
558: memset(&md, 0, sizeof(md));
1.1 deraadt 559: }
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