Mercurial > dropbear

comparison libtomcrypt/src/pk/rsa/rsa_sign_hash.c @ 399:a707e6148060

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
merge of '5fdf69ca60d1683cdd9f4c2595134bed26394834' and '6b61c50f4cf888bea302ac8fcf5dbb573b443251'
author Matt Johnston <matt@ucc.asn.au>
date Sat, 03 Feb 2007 08:20:34 +0000
parents 0cbe8f6dbf9e
children f849a5ca2efc
comparison
equal deleted inserted replaced
394:17d097fc111c 399:a707e6148060
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 rsa_sign_hash.c
15 RSA PKCS #1 v1.5 and v2 PSS sign hash, Tom St Denis and Andreas Lange
16 */
17
18 #ifdef MRSA
19
20 /**
21 PKCS #1 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 padding Type of padding (LTC_PKCS_1_PSS or LTC_PKCS_1_V1_5)
27 @param prng An active PRNG state
28 @param prng_idx The index of the PRNG desired
29 @param hash_idx The index of the hash desired
30 @param saltlen The length of the salt desired (octets)
31 @param key The private RSA key to use
32 @return CRYPT_OK if successful
33 */
34 int rsa_sign_hash_ex(const unsigned char *in, unsigned long inlen,
35 unsigned char *out, unsigned long *outlen,
36 int padding,
37 prng_state *prng, int prng_idx,
38 int hash_idx, unsigned long saltlen,
39 rsa_key *key)
40 {
41 unsigned long modulus_bitlen, modulus_bytelen, x, y;
42 int err;
43
44 LTC_ARGCHK(in != NULL);
45 LTC_ARGCHK(out != NULL);
46 LTC_ARGCHK(outlen != NULL);
47 LTC_ARGCHK(key != NULL);
48
49 /* valid padding? */
50 if ((padding != LTC_PKCS_1_V1_5) && (padding != LTC_PKCS_1_PSS)) {
51 return CRYPT_PK_INVALID_PADDING;
52 }
53
54 if (padding == LTC_PKCS_1_PSS) {
55 /* valid prng and hash ? */
56 if ((err = prng_is_valid(prng_idx)) != CRYPT_OK) {
57 return err;
58 }
59 if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) {
60 return err;
61 }
62 }
63
64 /* get modulus len in bits */
65 modulus_bitlen = mp_count_bits((key->N));
66
67 /* outlen must be at least the size of the modulus */
68 modulus_bytelen = mp_unsigned_bin_size((key->N));
69 if (modulus_bytelen > *outlen) {
70 *outlen = modulus_bytelen;
71 return CRYPT_BUFFER_OVERFLOW;
72 }
73
74 if (padding == LTC_PKCS_1_PSS) {
75 /* PSS pad the key */
76 x = *outlen;
77 if ((err = pkcs_1_pss_encode(in, inlen, saltlen, prng, prng_idx,
78 hash_idx, modulus_bitlen, out, &x)) != CRYPT_OK) {
79 return err;
80 }
81 } else {
82 /* PKCS #1 v1.5 pad the hash */
83 unsigned char *tmpin;
84 ltc_asn1_list digestinfo[2], siginfo[2];
85
86 /* not all hashes have OIDs... so sad */
87 if (hash_descriptor[hash_idx].OIDlen == 0) {
88 return CRYPT_INVALID_ARG;
89 }
90
91 /* construct the SEQUENCE
92 SEQUENCE {
93 SEQUENCE {hashoid OID
94 blah NULL
95 }
96 hash OCTET STRING
97 }
98 */
99 LTC_SET_ASN1(digestinfo, 0, LTC_ASN1_OBJECT_IDENTIFIER, hash_descriptor[hash_idx].OID, hash_descriptor[hash_idx].OIDlen);
100 LTC_SET_ASN1(digestinfo, 1, LTC_ASN1_NULL, NULL, 0);
101 LTC_SET_ASN1(siginfo, 0, LTC_ASN1_SEQUENCE, digestinfo, 2);
102 LTC_SET_ASN1(siginfo, 1, LTC_ASN1_OCTET_STRING, in, inlen);
103
104 /* allocate memory for the encoding */
105 y = mp_unsigned_bin_size(key->N);
106 tmpin = XMALLOC(y);
107 if (tmpin == NULL) {
108 return CRYPT_MEM;
109 }
110
111 if ((err = der_encode_sequence(siginfo, 2, tmpin, &y)) != CRYPT_OK) {
112 XFREE(tmpin);
113 return err;
114 }
115
116 x = *outlen;
117 if ((err = pkcs_1_v1_5_encode(tmpin, y, LTC_PKCS_1_EMSA,
118 modulus_bitlen, NULL, 0,
119 out, &x)) != CRYPT_OK) {
120 XFREE(tmpin);
121 return err;
122 }
123 XFREE(tmpin);
124 }
125
126 /* RSA encode it */
127 return ltc_mp.rsa_me(out, x, out, outlen, PK_PRIVATE, key);
128 }
129
130 #endif /* MRSA */
131
132 /* $Source: /cvs/libtom/libtomcrypt/src/pk/rsa/rsa_sign_hash.c,v $ */
133 /* $Revision: 1.9 $ */
134 /* $Date: 2006/11/09 23:15:39 $ */