Annotation of src/usr.bin/ssh/cipher.c, Revision 1.44
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"
1.44 ! markus 38: RCSID("$OpenBSD: cipher.c,v 1.43 2001/02/04 15:32:23 stevesk Exp $");
1.1 deraadt 39:
1.24 markus 40: #include "xmalloc.h"
1.42 markus 41: #include "log.h"
42: #include "cipher.h"
1.8 deraadt 43:
1.25 markus 44: #include <openssl/md5.h>
1.1 deraadt 45:
1.32 markus 46:
47: /* no encryption */
48: void
49: none_setkey(CipherContext *cc, const u_char *key, u_int keylen)
50: {
51: }
52: void
53: none_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
54: {
55: }
56: void
57: none_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
58: {
59: memcpy(dest, src, len);
60: }
61:
62: /* DES */
63: void
64: des_ssh1_setkey(CipherContext *cc, const u_char *key, u_int keylen)
65: {
1.34 markus 66: static int dowarn = 1;
67: if (dowarn) {
68: error("Warning: use of DES is strongly discouraged "
69: "due to cryptographic weaknesses");
70: dowarn = 0;
71: }
1.32 markus 72: des_set_key((void *)key, cc->u.des.key);
73: }
74: void
75: des_ssh1_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
76: {
77: memset(cc->u.des.iv, 0, sizeof(cc->u.des.iv));
78: }
79: void
80: des_ssh1_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
81: {
82: des_ncbc_encrypt(src, dest, len, cc->u.des.key, &cc->u.des.iv,
83: DES_ENCRYPT);
84: }
85: void
86: des_ssh1_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
87: {
88: des_ncbc_encrypt(src, dest, len, cc->u.des.key, &cc->u.des.iv,
89: DES_DECRYPT);
90: }
91:
92: /* 3DES */
93: void
94: des3_setkey(CipherContext *cc, const u_char *key, u_int keylen)
95: {
96: des_set_key((void *) key, cc->u.des3.key1);
97: des_set_key((void *) (key+8), cc->u.des3.key2);
98: des_set_key((void *) (key+16), cc->u.des3.key3);
99: }
100: void
101: des3_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
102: {
1.44 ! markus 103: memset(cc->u.des3.iv1, 0, sizeof(cc->u.des3.iv1));
1.32 markus 104: memset(cc->u.des3.iv2, 0, sizeof(cc->u.des3.iv2));
105: memset(cc->u.des3.iv3, 0, sizeof(cc->u.des3.iv3));
106: if (iv == NULL)
107: return;
108: memcpy(cc->u.des3.iv3, (char *)iv, 8);
109: }
110: void
111: des3_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
112: {
113: des_ede3_cbc_encrypt(src, dest, len,
114: cc->u.des3.key1, cc->u.des3.key2, cc->u.des3.key3,
115: &cc->u.des3.iv3, DES_ENCRYPT);
116: }
117: void
118: des3_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
119: {
120: des_ede3_cbc_encrypt(src, dest, len,
121: cc->u.des3.key1, cc->u.des3.key2, cc->u.des3.key3,
122: &cc->u.des3.iv3, DES_DECRYPT);
123: }
124:
1.1 deraadt 125: /*
1.24 markus 126: * This is used by SSH1:
127: *
1.23 deraadt 128: * What kind of triple DES are these 2 routines?
1.1 deraadt 129: *
130: * Why is there a redundant initialization vector?
131: *
132: * If only iv3 was used, then, this would till effect have been
133: * outer-cbc. However, there is also a private iv1 == iv2 which
134: * perhaps makes differential analysis easier. On the other hand, the
135: * private iv1 probably makes the CRC-32 attack ineffective. This is a
136: * result of that there is no longer any known iv1 to use when
137: * choosing the X block.
138: */
139: void
1.32 markus 140: des3_ssh1_setkey(CipherContext *cc, const u_char *key, u_int keylen)
141: {
142: des_set_key((void *) key, cc->u.des3.key1);
143: des_set_key((void *) (key+8), cc->u.des3.key2);
144: if (keylen <= 16)
145: des_set_key((void *) key, cc->u.des3.key3);
146: else
147: des_set_key((void *) (key+16), cc->u.des3.key3);
148: }
149: void
150: des3_ssh1_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
151: u_int len)
1.1 deraadt 152: {
1.44 ! markus 153: des_ncbc_encrypt(src, dest, len, cc->u.des3.key1, &cc->u.des3.iv1,
! 154: DES_ENCRYPT);
! 155: des_ncbc_encrypt(dest, dest, len, cc->u.des3.key2, &cc->u.des3.iv2,
! 156: DES_DECRYPT);
! 157: des_ncbc_encrypt(dest, dest, len, cc->u.des3.key3, &cc->u.des3.iv3,
! 158: DES_ENCRYPT);
1.1 deraadt 159: }
160: void
1.32 markus 161: des3_ssh1_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
162: u_int len)
1.1 deraadt 163: {
1.44 ! markus 164: des_ncbc_encrypt(src, dest, len, cc->u.des3.key3, &cc->u.des3.iv3,
! 165: DES_DECRYPT);
! 166: des_ncbc_encrypt(dest, dest, len, cc->u.des3.key2, &cc->u.des3.iv2,
! 167: DES_ENCRYPT);
! 168: des_ncbc_encrypt(dest, dest, len, cc->u.des3.key1, &cc->u.des3.iv1,
! 169: DES_DECRYPT);
1.1 deraadt 170: }
171:
1.32 markus 172: /* Blowfish */
173: void
174: blowfish_setkey(CipherContext *cc, const u_char *key, u_int keylen)
175: {
1.41 markus 176: BF_set_key(&cc->u.bf.key, keylen, (u_char *)key);
1.32 markus 177: }
178: void
179: blowfish_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
180: {
181: if (iv == NULL)
182: memset(cc->u.bf.iv, 0, 8);
183: else
184: memcpy(cc->u.bf.iv, (char *)iv, 8);
185: }
186: void
187: blowfish_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
188: u_int len)
189: {
190: BF_cbc_encrypt((void *)src, dest, len, &cc->u.bf.key, cc->u.bf.iv,
191: BF_ENCRYPT);
192: }
193: void
194: blowfish_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
195: u_int len)
196: {
197: BF_cbc_encrypt((void *)src, dest, len, &cc->u.bf.key, cc->u.bf.iv,
198: BF_DECRYPT);
199: }
200:
1.1 deraadt 201: /*
1.24 markus 202: * SSH1 uses a variation on Blowfish, all bytes must be swapped before
1.1 deraadt 203: * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
204: */
1.16 markus 205: static void
1.41 markus 206: swap_bytes(const u_char *src, u_char *dst, int n)
1.1 deraadt 207: {
1.37 markus 208: char c[4];
209:
210: /* Process 4 bytes every lap. */
211: for (n = n / 4; n > 0; n--) {
212: c[3] = *src++;
213: c[2] = *src++;
214: c[1] = *src++;
215: c[0] = *src++;
216:
217: *dst++ = c[0];
218: *dst++ = c[1];
219: *dst++ = c[2];
220: *dst++ = c[3];
1.16 markus 221: }
1.1 deraadt 222: }
223:
1.32 markus 224: void
225: blowfish_ssh1_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
226: u_int len)
227: {
228: swap_bytes(src, dest, len);
229: BF_cbc_encrypt((void *)dest, dest, len, &cc->u.bf.key, cc->u.bf.iv,
230: BF_ENCRYPT);
231: swap_bytes(dest, dest, len);
232: }
233: void
234: blowfish_ssh1_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
235: u_int len)
1.4 provos 236: {
1.32 markus 237: swap_bytes(src, dest, len);
238: BF_cbc_encrypt((void *)dest, dest, len, &cc->u.bf.key, cc->u.bf.iv,
239: BF_DECRYPT);
240: swap_bytes(dest, dest, len);
241: }
1.1 deraadt 242:
1.32 markus 243: /* alleged rc4 */
244: void
245: arcfour_setkey(CipherContext *cc, const u_char *key, u_int keylen)
246: {
247: RC4_set_key(&cc->u.rc4, keylen, (u_char *)key);
248: }
249: void
250: arcfour_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
251: {
252: RC4(&cc->u.rc4, len, (u_char *)src, dest);
253: }
1.1 deraadt 254:
1.32 markus 255: /* CAST */
256: void
257: cast_setkey(CipherContext *cc, const u_char *key, u_int keylen)
258: {
1.41 markus 259: CAST_set_key(&cc->u.cast.key, keylen, (u_char *) key);
1.32 markus 260: }
261: void
262: cast_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
1.1 deraadt 263: {
1.43 stevesk 264: if (iv == NULL)
1.32 markus 265: fatal("no IV for %s.", cc->cipher->name);
266: memcpy(cc->u.cast.iv, (char *)iv, 8);
1.22 markus 267: }
1.32 markus 268: void
269: cast_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
1.22 markus 270: {
1.32 markus 271: CAST_cbc_encrypt(src, dest, len, &cc->u.cast.key, cc->u.cast.iv,
272: CAST_ENCRYPT);
1.1 deraadt 273: }
1.32 markus 274: void
275: cast_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
1.22 markus 276: {
1.32 markus 277: CAST_cbc_encrypt(src, dest, len, &cc->u.cast.key, cc->u.cast.iv,
278: CAST_DECRYPT);
1.22 markus 279: }
1.1 deraadt 280:
1.35 markus 281: /* RIJNDAEL */
282:
283: #define RIJNDAEL_BLOCKSIZE 16
284: void
285: rijndael_setkey(CipherContext *cc, const u_char *key, u_int keylen)
286: {
1.40 markus 287: rijndael_set_key(&cc->u.rijndael.enc, (u4byte *)key, 8*keylen, 1);
288: rijndael_set_key(&cc->u.rijndael.dec, (u4byte *)key, 8*keylen, 0);
1.35 markus 289: }
290: void
291: rijndael_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
292: {
1.43 stevesk 293: if (iv == NULL)
1.40 markus 294: fatal("no IV for %s.", cc->cipher->name);
295: memcpy((u_char *)cc->u.rijndael.iv, iv, RIJNDAEL_BLOCKSIZE);
1.35 markus 296: }
297: void
298: rijndael_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
299: u_int len)
300: {
1.40 markus 301: rijndael_ctx *ctx = &cc->u.rijndael.enc;
302: u4byte *iv = cc->u.rijndael.iv;
303: u4byte in[4];
304: u4byte *cprev, *cnow, *plain;
305: int i, blocks = len / RIJNDAEL_BLOCKSIZE;
1.35 markus 306: if (len == 0)
307: return;
308: if (len % RIJNDAEL_BLOCKSIZE)
309: fatal("rijndael_cbc_encrypt: bad len %d", len);
1.40 markus 310: cnow = (u4byte*) dest;
311: plain = (u4byte*) src;
1.35 markus 312: cprev = iv;
1.40 markus 313: for(i = 0; i < blocks; i++, plain+=4, cnow+=4) {
314: in[0] = plain[0] ^ cprev[0];
315: in[1] = plain[1] ^ cprev[1];
316: in[2] = plain[2] ^ cprev[2];
317: in[3] = plain[3] ^ cprev[3];
1.35 markus 318: rijndael_encrypt(ctx, in, cnow);
319: cprev = cnow;
320: }
321: memcpy(iv, cprev, RIJNDAEL_BLOCKSIZE);
322: }
323:
324: void
325: rijndael_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
326: u_int len)
327: {
1.40 markus 328: rijndael_ctx *ctx = &cc->u.rijndael.dec;
329: u4byte *iv = cc->u.rijndael.iv;
330: u4byte ivsaved[4];
331: u4byte *cnow = (u4byte*) (src+len-RIJNDAEL_BLOCKSIZE);
332: u4byte *plain = (u4byte*) (dest+len-RIJNDAEL_BLOCKSIZE);
333: u4byte *ivp;
334: int i, blocks = len / RIJNDAEL_BLOCKSIZE;
1.35 markus 335: if (len == 0)
336: return;
337: if (len % RIJNDAEL_BLOCKSIZE)
338: fatal("rijndael_cbc_decrypt: bad len %d", len);
339: memcpy(ivsaved, cnow, RIJNDAEL_BLOCKSIZE);
1.40 markus 340: for(i = blocks; i > 0; i--, cnow-=4, plain-=4) {
1.35 markus 341: rijndael_decrypt(ctx, cnow, plain);
1.40 markus 342: ivp = (i == 1) ? iv : cnow-4;
343: plain[0] ^= ivp[0];
344: plain[1] ^= ivp[1];
345: plain[2] ^= ivp[2];
346: plain[3] ^= ivp[3];
1.35 markus 347: }
348: memcpy(iv, ivsaved, RIJNDAEL_BLOCKSIZE);
349: }
1.32 markus 350:
351: Cipher ciphers[] = {
352: { "none",
353: SSH_CIPHER_NONE, 8, 0,
354: none_setkey, none_setiv,
355: none_crypt, none_crypt },
1.34 markus 356: { "des",
357: SSH_CIPHER_DES, 8, 8,
358: des_ssh1_setkey, des_ssh1_setiv,
359: des_ssh1_encrypt, des_ssh1_decrypt },
1.32 markus 360: { "3des",
361: SSH_CIPHER_3DES, 8, 16,
362: des3_ssh1_setkey, des3_setiv,
363: des3_ssh1_encrypt, des3_ssh1_decrypt },
364: { "blowfish",
365: SSH_CIPHER_BLOWFISH, 8, 16,
366: blowfish_setkey, blowfish_setiv,
367: blowfish_ssh1_encrypt, blowfish_ssh1_decrypt },
368:
369: { "3des-cbc",
370: SSH_CIPHER_SSH2, 8, 24,
371: des3_setkey, des3_setiv,
372: des3_cbc_encrypt, des3_cbc_decrypt },
373: { "blowfish-cbc",
374: SSH_CIPHER_SSH2, 8, 16,
375: blowfish_setkey, blowfish_setiv,
376: blowfish_cbc_encrypt, blowfish_cbc_decrypt },
377: { "cast128-cbc",
378: SSH_CIPHER_SSH2, 8, 16,
379: cast_setkey, cast_setiv,
380: cast_cbc_encrypt, cast_cbc_decrypt },
381: { "arcfour",
382: SSH_CIPHER_SSH2, 8, 16,
383: arcfour_setkey, none_setiv,
384: arcfour_crypt, arcfour_crypt },
1.35 markus 385: { "aes128-cbc",
386: SSH_CIPHER_SSH2, 16, 16,
387: rijndael_setkey, rijndael_setiv,
388: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
389: { "aes192-cbc",
390: SSH_CIPHER_SSH2, 16, 24,
391: rijndael_setkey, rijndael_setiv,
392: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
393: { "aes256-cbc",
394: SSH_CIPHER_SSH2, 16, 32,
395: rijndael_setkey, rijndael_setiv,
396: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
397: { "rijndael128-cbc",
398: SSH_CIPHER_SSH2, 16, 16,
399: rijndael_setkey, rijndael_setiv,
400: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
401: { "rijndael192-cbc",
402: SSH_CIPHER_SSH2, 16, 24,
403: rijndael_setkey, rijndael_setiv,
404: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
405: { "rijndael256-cbc",
406: SSH_CIPHER_SSH2, 16, 32,
407: rijndael_setkey, rijndael_setiv,
408: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
409: { "rijndael-cbc@lysator.liu.se",
410: SSH_CIPHER_SSH2, 16, 32,
411: rijndael_setkey, rijndael_setiv,
412: rijndael_cbc_encrypt, rijndael_cbc_decrypt },
1.43 stevesk 413: { NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL, NULL, NULL, NULL }
1.32 markus 414: };
415:
416: /*--*/
1.1 deraadt 417:
1.41 markus 418: u_int
1.34 markus 419: cipher_mask_ssh1(int client)
1.1 deraadt 420: {
1.41 markus 421: u_int mask = 0;
1.34 markus 422: mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */
423: mask |= 1 << SSH_CIPHER_BLOWFISH;
424: if (client) {
425: mask |= 1 << SSH_CIPHER_DES;
1.32 markus 426: }
427: return mask;
1.1 deraadt 428: }
429:
1.32 markus 430: Cipher *
431: cipher_by_name(const char *name)
432: {
433: Cipher *c;
434: for (c = ciphers; c->name != NULL; c++)
435: if (strcasecmp(c->name, name) == 0)
436: return c;
437: return NULL;
438: }
439:
440: Cipher *
441: cipher_by_number(int id)
442: {
443: Cipher *c;
444: for (c = ciphers; c->name != NULL; c++)
445: if (c->number == id)
446: return c;
447: return NULL;
448: }
1.24 markus 449:
450: #define CIPHER_SEP ","
451: int
452: ciphers_valid(const char *names)
453: {
1.32 markus 454: Cipher *c;
1.29 ho 455: char *ciphers, *cp;
1.24 markus 456: char *p;
457:
1.27 markus 458: if (names == NULL || strcmp(names, "") == 0)
1.24 markus 459: return 0;
1.29 ho 460: ciphers = cp = xstrdup(names);
1.32 markus 461: for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
1.29 ho 462: (p = strsep(&cp, CIPHER_SEP))) {
1.32 markus 463: c = cipher_by_name(p);
464: if (c == NULL || c->number != SSH_CIPHER_SSH2) {
465: debug("bad cipher %s [%s]", p, names);
1.24 markus 466: xfree(ciphers);
467: return 0;
1.32 markus 468: } else {
1.36 markus 469: debug3("cipher ok: %s [%s]", p, names);
1.24 markus 470: }
471: }
1.36 markus 472: debug3("ciphers ok: [%s]", names);
1.24 markus 473: xfree(ciphers);
474: return 1;
475: }
476:
1.18 markus 477: /*
478: * Parses the name of the cipher. Returns the number of the corresponding
479: * cipher, or -1 on error.
480: */
1.1 deraadt 481:
1.4 provos 482: int
483: cipher_number(const char *name)
1.1 deraadt 484: {
1.32 markus 485: Cipher *c;
1.27 markus 486: if (name == NULL)
487: return -1;
1.32 markus 488: c = cipher_by_name(name);
489: return (c==NULL) ? -1 : c->number;
1.1 deraadt 490: }
491:
1.32 markus 492: char *
493: cipher_name(int id)
1.1 deraadt 494: {
1.32 markus 495: Cipher *c = cipher_by_number(id);
496: return (c==NULL) ? "<unknown>" : c->name;
1.1 deraadt 497: }
498:
1.26 markus 499: void
1.32 markus 500: cipher_init(CipherContext *cc, Cipher *cipher,
501: const u_char *key, u_int keylen, const u_char *iv, u_int ivlen)
1.16 markus 502: {
1.32 markus 503: if (keylen < cipher->key_len)
504: fatal("cipher_init: key length %d is insufficient for %s.",
505: keylen, cipher->name);
506: if (iv != NULL && ivlen < cipher->block_size)
507: fatal("cipher_init: iv length %d is insufficient for %s.",
508: ivlen, cipher->name);
509: cc->cipher = cipher;
510: cipher->setkey(cc, key, keylen);
511: cipher->setiv(cc, iv, ivlen);
1.1 deraadt 512: }
1.21 markus 513:
1.26 markus 514: void
1.32 markus 515: cipher_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
516: {
517: if (len % cc->cipher->block_size)
518: fatal("cipher_encrypt: bad plaintext length %d", len);
519: cc->cipher->encrypt(cc, dest, src, len);
1.21 markus 520: }
521:
1.26 markus 522: void
1.32 markus 523: cipher_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
1.16 markus 524: {
1.32 markus 525: if (len % cc->cipher->block_size)
526: fatal("cipher_decrypt: bad ciphertext length %d", len);
527: cc->cipher->decrypt(cc, dest, src, len);
1.16 markus 528: }
1.1 deraadt 529:
1.32 markus 530: /*
531: * Selects the cipher, and keys if by computing the MD5 checksum of the
532: * passphrase and using the resulting 16 bytes as the key.
533: */
1.1 deraadt 534:
1.26 markus 535: void
1.32 markus 536: cipher_set_key_string(CipherContext *cc, Cipher *cipher,
537: const char *passphrase)
1.16 markus 538: {
1.32 markus 539: MD5_CTX md;
1.41 markus 540: u_char digest[16];
1.32 markus 541:
542: MD5_Init(&md);
543: MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase));
544: MD5_Final(digest, &md);
1.16 markus 545:
1.32 markus 546: cipher_init(cc, cipher, digest, 16, NULL, 0);
1.16 markus 547:
1.32 markus 548: memset(digest, 0, sizeof(digest));
549: memset(&md, 0, sizeof(md));
1.1 deraadt 550: }
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