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comparison src/pk/rsa/rsa_sign_hash.c @ 191:1c15b283127b libtomcrypt-orig

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Import of libtomcrypt 1.02 with manual path rename rearrangement etc
author Matt Johnston <matt@ucc.asn.au>
date Fri, 06 May 2005 13:23:02 +0000
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children 39d5d58461d6
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143:5d99163f7e32 191:1c15b283127b
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 rsa_sign_hash.c
15 RSA PKCS v2 PSS sign hash, Tom St Denis
16 */
17
18 #ifdef MRSA
19
20 /**
21 (PKCS #1, v2.0) PSS pad then sign
22 @param in The hash to sign
23 @param inlen The length of the hash to sign (octets)
24 @param out [out] The signature
25 @param outlen [in/out] The max size and resulting size of the signature
26 @param prng An active PRNG state
27 @param prng_idx The index of the PRNG desired
28 @param hash_idx The index of the hash desired
29 @param saltlen The length of the salt desired (octets)
30 @param key The private RSA key to use
31 @return CRYPT_OK if successful
32 */
33 int rsa_sign_hash(const unsigned char *in, unsigned long inlen,
34 unsigned char *out, unsigned long *outlen,
35 prng_state *prng, int prng_idx,
36 int hash_idx, unsigned long saltlen,
37 rsa_key *key)
38 {
39 unsigned long modulus_bitlen, modulus_bytelen, x;
40 int err;
41
42 LTC_ARGCHK(in != NULL);
43 LTC_ARGCHK(out != NULL);
44 LTC_ARGCHK(outlen != NULL);
45 LTC_ARGCHK(key != NULL);
46
47 /* valid prng and hash ? */
48 if ((err = prng_is_valid(prng_idx)) != CRYPT_OK) {
49 return err;
50 }
51 if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) {
52 return err;
53 }
54
55 /* get modulus len in bits */
56 modulus_bitlen = mp_count_bits(&(key->N));
57
58 /* outlen must be at least the size of the modulus */
59 modulus_bytelen = mp_unsigned_bin_size(&(key->N));
60 if (modulus_bytelen > *outlen) {
61 return CRYPT_BUFFER_OVERFLOW;
62 }
63
64 /* PSS pad the key */
65 x = *outlen;
66 if ((err = pkcs_1_pss_encode(in, inlen, saltlen, prng, prng_idx,
67 hash_idx, modulus_bitlen, out, &x)) != CRYPT_OK) {
68 return err;
69 }
70
71 /* RSA encode it */
72 return rsa_exptmod(out, x, out, outlen, PK_PRIVATE, key);
73 }
74
75 #endif /* MRSA */