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comparison libtomcrypt/src/mac/xcbc/xcbc_init.c @ 382:0cbe8f6dbf9e

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propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 2af22fb4e878750b88f80f90d439b316d229796f) to branch 'au.asn.ucc.matt.dropbear' (head 02c413252c90e9de8e03d91e9939dde3029f5c0a)
author Matt Johnston <matt@ucc.asn.au>
date Thu, 11 Jan 2007 02:41:05 +0000
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children f849a5ca2efc
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379:b66a00272a90 382:0cbe8f6dbf9e
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.com
10 */
11 #include "tomcrypt.h"
12
13 /**
14 @file xcbc_init.c
15 XCBC Support, start an XCBC state
16 */
17
18 #ifdef LTC_XCBC
19
20 /** Initialize XCBC-MAC state
21 @param xcbc [out] XCBC state to initialize
22 @param cipher Index of cipher to use
23 @param key [in] Secret key
24 @param keylen Length of secret key in octets
25 Return CRYPT_OK on success
26 */
27 int xcbc_init(xcbc_state *xcbc, int cipher, const unsigned char *key, unsigned long keylen)
28 {
29 int x, y, err;
30 symmetric_key *skey;
31
32 LTC_ARGCHK(xcbc != NULL);
33 LTC_ARGCHK(key != NULL);
34
35 /* schedule the key */
36 if ((err = cipher_is_valid(cipher)) != CRYPT_OK) {
37 return err;
38 }
39
40 #ifdef LTC_FAST
41 if (cipher_descriptor[cipher].block_length % sizeof(LTC_FAST_TYPE)) {
42 return CRYPT_INVALID_ARG;
43 }
44 #endif
45
46 /* schedule the user key */
47 skey = XCALLOC(1, sizeof(*skey));
48 if (skey == NULL) {
49 return CRYPT_MEM;
50 }
51
52 if ((err = cipher_descriptor[cipher].setup(key, keylen, 0, skey)) != CRYPT_OK) {
53 goto done;
54 }
55
56 /* make the three keys */
57 for (y = 0; y < 3; y++) {
58 for (x = 0; x < cipher_descriptor[cipher].block_length; x++) {
59 xcbc->K[y][x] = y + 1;
60 }
61 cipher_descriptor[cipher].ecb_encrypt(xcbc->K[y], xcbc->K[y], skey);
62 }
63
64 /* setup K1 */
65 err = cipher_descriptor[cipher].setup(xcbc->K[0], cipher_descriptor[cipher].block_length, 0, &xcbc->key);
66
67 /* setup struct */
68 zeromem(xcbc->IV, cipher_descriptor[cipher].block_length);
69 xcbc->blocksize = cipher_descriptor[cipher].block_length;
70 xcbc->cipher = cipher;
71 xcbc->buflen = 0;
72 done:
73 cipher_descriptor[cipher].done(skey);
74 #ifdef LTC_CLEAN_STACK
75 zeromem(skey, sizeof(*skey));
76 #endif
77 XFREE(skey);
78 return err;
79 }
80
81 #endif
82
83 /* $Source: /cvs/libtom/libtomcrypt/src/mac/xcbc/xcbc_init.c,v $ */
84 /* $Revision: 1.4 $ */
85 /* $Date: 2006/11/07 03:23:46 $ */
86