comparison cbc_encrypt.c @ 0:d7da3b1e1540 libtomcrypt

put back the 0.95 makefile which was inadvertently merged over
author Matt Johnston <matt@ucc.asn.au>
date Mon, 31 May 2004 18:21:40 +0000
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-1:000000000000 0:d7da3b1e1540
1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
2 *
3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner.
5 *
6 * The library is free for all purposes without any express
7 * guarantee it works.
8 *
9 * Tom St Denis, [email protected], http://libtomcrypt.org
10 */
11 #include "mycrypt.h"
12
13 #ifdef CBC
14
15 int cbc_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_CBC *cbc)
16 {
17 int x, err;
18 unsigned char tmp[MAXBLOCKSIZE];
19
20 _ARGCHK(pt != NULL);
21 _ARGCHK(ct != NULL);
22 _ARGCHK(cbc != NULL);
23
24 if ((err = cipher_is_valid(cbc->cipher)) != CRYPT_OK) {
25 return err;
26 }
27
28 /* is blocklen valid? */
29 if (cbc->blocklen < 0 || cbc->blocklen > (int)sizeof(cbc->IV)) {
30 return CRYPT_INVALID_ARG;
31 }
32
33 /* xor IV against plaintext */
34 for (x = 0; x < cbc->blocklen; x++) {
35 tmp[x] = pt[x] ^ cbc->IV[x];
36 }
37
38 /* encrypt */
39 cipher_descriptor[cbc->cipher].ecb_encrypt(tmp, ct, &cbc->key);
40
41 /* store IV [ciphertext] for a future block */
42 for (x = 0; x < cbc->blocklen; x++) {
43 cbc->IV[x] = ct[x];
44 }
45
46 #ifdef CLEAN_STACK
47 zeromem(tmp, sizeof(tmp));
48 #endif
49 return CRYPT_OK;
50 }
51
52 #endif