Mercurial > dropbear
diff libtomcrypt/src/pk/rsa/rsa_sign_hash.c @ 285:1b9e69c058d2
propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
to branch 'au.asn.ucc.matt.dropbear' (head fdf4a7a3b97ae5046139915de7e40399cceb2c01)
author | Matt Johnston <matt@ucc.asn.au> |
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date | Wed, 08 Mar 2006 13:23:58 +0000 |
parents | |
children | 0cbe8f6dbf9e |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/libtomcrypt/src/pk/rsa/rsa_sign_hash.c Wed Mar 08 13:23:58 2006 +0000 @@ -0,0 +1,79 @@ +/* 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, [email protected], 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 $ */