Mercurial > dropbear

annotate ocb_decrypt.c @ 8:059ec00f32a1 libtomcrypt

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Missing ranlib in makefile for library
author Matt Johnston <matt@ucc.asn.au>
date Wed, 02 Jun 2004 08:31:25 +0000
parents d7da3b1e1540
children 6362d3854bb4
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
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
12 /* OCB Implementation by Tom St Denis */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
13 #include "mycrypt.h"
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 #ifdef OCB_MODE
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 ocb_decrypt(ocb_state *ocb, const unsigned char *ct, unsigned char *pt)
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
18 {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
19 unsigned char Z[MAXBLOCKSIZE], tmp[MAXBLOCKSIZE];
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
20 int err, x;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
21
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
22 _ARGCHK(ocb != NULL);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
23 _ARGCHK(pt != NULL);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
24 _ARGCHK(ct != NULL);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
25 if ((err = cipher_is_valid(ocb->cipher)) != CRYPT_OK) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
26 return err;
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 if (ocb->block_len != cipher_descriptor[ocb->cipher].block_length) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
29 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
30 }
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 /* Get Z[i] value */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
33 ocb_shift_xor(ocb, Z);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
34
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
35 /* xor ct in, encrypt, xor Z out */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
36 for (x = 0; x < ocb->block_len; x++) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
37 tmp[x] = ct[x] ^ Z[x];
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
38 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
39 cipher_descriptor[ocb->cipher].ecb_decrypt(tmp, pt, &ocb->key);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
40 for (x = 0; x < ocb->block_len; x++) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
41 pt[x] ^= Z[x];
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
42 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
43
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
44 /* compute checksum */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
45 for (x = 0; x < ocb->block_len; x++) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
46 ocb->checksum[x] ^= pt[x];
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
47 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
48
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
49
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
50 #ifdef CLEAN_STACK
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
51 zeromem(Z, sizeof(Z));
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
52 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
53 #endif
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
54 return CRYPT_OK;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
55 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
56
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
57 #endif
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
58