| /* LibTomCrypt, modular cryptographic library -- Tom St Denis |
| * |
| * LibTomCrypt is a library that provides various cryptographic |
| * algorithms in a highly modular and flexible manner. |
| * |
| * The library is free for all purposes without any express |
| * guarantee it works. |
| * |
| * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org |
| */ |
| #include "tomcrypt.h" |
| |
| /** |
| @file rsa_sign_hash.c |
| RSA PKCS v2 PSS sign hash, Tom St Denis |
| */ |
| |
| #ifdef MRSA |
| |
| /** |
| (PKCS #1, v2.0) PSS pad then sign |
| @param in The hash to sign |
| @param inlen The length of the hash to sign (octets) |
| @param out [out] The signature |
| @param outlen [in/out] The max size and resulting size of the signature |
| @param prng An active PRNG state |
| @param prng_idx The index of the PRNG desired |
| @param hash_idx The index of the hash desired |
| @param saltlen The length of the salt desired (octets) |
| @param key The private RSA key to use |
| @return CRYPT_OK if successful |
| */ |
| int rsa_sign_hash(const unsigned char *in, unsigned long inlen, |
| unsigned char *out, unsigned long *outlen, |
| prng_state *prng, int prng_idx, |
| int hash_idx, unsigned long saltlen, |
| rsa_key *key) |
| { |
| unsigned long modulus_bitlen, modulus_bytelen, x; |
| int err; |
| |
| LTC_ARGCHK(in != NULL); |
| LTC_ARGCHK(out != NULL); |
| LTC_ARGCHK(outlen != NULL); |
| LTC_ARGCHK(key != NULL); |
| |
| /* valid prng and hash ? */ |
| if ((err = prng_is_valid(prng_idx)) != CRYPT_OK) { |
| return err; |
| } |
| if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) { |
| return err; |
| } |
| |
| /* get modulus len in bits */ |
| modulus_bitlen = mp_count_bits(&(key->N)); |
| |
| /* outlen must be at least the size of the modulus */ |
| modulus_bytelen = mp_unsigned_bin_size(&(key->N)); |
| if (modulus_bytelen > *outlen) { |
| return CRYPT_BUFFER_OVERFLOW; |
| } |
| |
| /* PSS pad the key */ |
| x = *outlen; |
| if ((err = pkcs_1_pss_encode(in, inlen, saltlen, prng, prng_idx, |
| hash_idx, modulus_bitlen, out, &x)) != CRYPT_OK) { |
| return err; |
| } |
| |
| /* RSA encode it */ |
| return rsa_exptmod(out, x, out, outlen, PK_PRIVATE, key); |
| } |
| |
| #endif /* MRSA */ |
| |
| /* $Source: /cvs/libtom/libtomcrypt/src/pk/rsa/rsa_sign_hash.c,v $ */ |
| /* $Revision: 1.3 $ */ |
| /* $Date: 2005/05/05 14:35:59 $ */ |