Mercurial > dropbear

comparison libtomcrypt/src/modes/cbc/cbc_encrypt.c @ 285:1b9e69c058d2

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3) to branch 'au.asn.ucc.matt.dropbear' (head fdf4a7a3b97ae5046139915de7e40399cceb2c01)
author Matt Johnston <matt@ucc.asn.au>
date Wed, 08 Mar 2006 13:23:58 +0000
parents
children 0cbe8f6dbf9e
comparison
equal deleted inserted replaced
281:997e6f7dc01e 285:1b9e69c058d2
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 "tomcrypt.h"
12
13 /**
14 @file cbc_encrypt.c
15 CBC implementation, encrypt block, Tom St Denis
16 */
17
18
19 #ifdef CBC
20
21 /**
22 CBC encrypt
23 @param pt Plaintext
24 @param ct [out] Ciphertext
25 @param len The number of bytes to process (must be multiple of block length)
26 @param cbc CBC state
27 @return CRYPT_OK if successful
28 */
29 int cbc_encrypt(const unsigned char *pt, unsigned char *ct, unsigned long len, symmetric_CBC *cbc)
30 {
31 int x, err;
32
33 LTC_ARGCHK(pt != NULL);
34 LTC_ARGCHK(ct != NULL);
35 LTC_ARGCHK(cbc != NULL);
36
37 if ((err = cipher_is_valid(cbc->cipher)) != CRYPT_OK) {
38 return err;
39 }
40
41 /* is blocklen valid? */
42 if (cbc->blocklen < 0 || cbc->blocklen > (int)sizeof(cbc->IV)) {
43 return CRYPT_INVALID_ARG;
44 }
45
46 if (len % cbc->blocklen) {
47 return CRYPT_INVALID_ARG;
48 }
49 #ifdef LTC_FAST
50 if (len % sizeof(LTC_FAST_TYPE)) {
51 return CRYPT_INVALID_ARG;
52 }
53 #endif
54
55 if (cipher_descriptor[cbc->cipher].accel_cbc_encrypt != NULL) {
56 cipher_descriptor[cbc->cipher].accel_cbc_encrypt(pt, ct, len / cbc->blocklen, cbc->IV, &cbc->key);
57 } else {
58 while (len) {
59 /* xor IV against plaintext */
60 #if defined(LTC_FAST)
61 for (x = 0; x < cbc->blocklen; x += sizeof(LTC_FAST_TYPE)) {
62 *((LTC_FAST_TYPE*)((unsigned char *)cbc->IV + x)) ^= *((LTC_FAST_TYPE*)((unsigned char *)pt + x));
63 }
64 #else
65 for (x = 0; x < cbc->blocklen; x++) {
66 cbc->IV[x] ^= pt[x];
67 }
68 #endif
69
70 /* encrypt */
71 cipher_descriptor[cbc->cipher].ecb_encrypt(cbc->IV, ct, &cbc->key);
72
73 /* store IV [ciphertext] for a future block */
74 #if defined(LTC_FAST)
75 for (x = 0; x < cbc->blocklen; x += sizeof(LTC_FAST_TYPE)) {
76 *((LTC_FAST_TYPE*)((unsigned char *)cbc->IV + x)) = *((LTC_FAST_TYPE*)((unsigned char *)ct + x));
77 }
78 #else
79 for (x = 0; x < cbc->blocklen; x++) {
80 cbc->IV[x] = ct[x];
81 }
82 #endif
83
84 ct += cbc->blocklen;
85 pt += cbc->blocklen;
86 len -= cbc->blocklen;
87 }
88 }
89 return CRYPT_OK;
90 }
91
92 #endif
93
94 /* $Source: /cvs/libtom/libtomcrypt/src/modes/cbc/cbc_encrypt.c,v $ */
95 /* $Revision: 1.7 $ */
96 /* $Date: 2005/05/05 14:35:59 $ */