annotate cbc_encrypt.c @ 17:1a066933c5e1 libtomcrypt

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