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comparison pkcs_1_mgf1.c @ 3:7faae8f46238 libtomcrypt-orig

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Branch renaming
author Matt Johnston <matt@ucc.asn.au>
date Mon, 31 May 2004 18:25:41 +0000
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children 5d99163f7e32
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-1:000000000000 3:7faae8f46238
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 /* The Mask Generation Function (MGF1) for PKCS #1 -- Tom St Denis */
14
15 #ifdef PKCS_1
16
17 int pkcs_1_mgf1(const unsigned char *seed, unsigned long seedlen,
18 int hash_idx,
19 unsigned char *mask, unsigned long masklen)
20 {
21 unsigned long hLen, counter, x;
22 int err;
23 hash_state md;
24 unsigned char buf[MAXBLOCKSIZE];
25
26 _ARGCHK(seed != NULL);
27 _ARGCHK(mask != NULL);
28
29 /* ensure valid hash */
30 if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) {
31 return err;
32 }
33
34 /* get hash output size */
35 hLen = hash_descriptor[hash_idx].hashsize;
36
37 /* start counter */
38 counter = 0;
39
40 while (masklen > 0) {
41 /* handle counter */
42 STORE32H(counter, buf);
43 ++counter;
44
45 /* get hash of seed || counter */
46 hash_descriptor[hash_idx].init(&md);
47 if ((err = hash_descriptor[hash_idx].process(&md, seed, seedlen)) != CRYPT_OK) {
48 return err;
49 }
50 if ((err = hash_descriptor[hash_idx].process(&md, buf, 4)) != CRYPT_OK) {
51 return err;
52 }
53 if ((err = hash_descriptor[hash_idx].done(&md, buf)) != CRYPT_OK) {
54 return err;
55 }
56
57 /* store it */
58 for (x = 0; x < hLen && masklen > 0; x++, masklen--) {
59 *mask++ = buf[x];
60 }
61 }
62
63 return CRYPT_OK;
64 }
65
66 #endif /* PKCS_1 */