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/*-
* Copyright (c) 2017-2024 Ribose Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef RNP_DSA_H_
#define RNP_DSA_H_
#include <rnp/rnp_def.h>
#include <repgp/repgp_def.h>
#include "crypto/rng.h"
#include "crypto/mpi.hpp"
#include "crypto/mem.h"
namespace pgp {
namespace dsa {
class Signature {
public:
mpi r{};
mpi s{};
};
class Key {
public:
mpi p{};
mpi q{};
mpi g{};
mpi y{};
/* secret mpi */
mpi x{};
void
clear_secret()
{
x.forget();
}
~Key()
{
clear_secret();
}
/**
* @brief Checks DSA key fields for validity
*
* @param rng initialized PRNG
* @param secret flag which tells whether key has populated secret fields
*
* @return RNP_SUCCESS if key is valid or error code otherwise
*/
rnp_result_t validate(rnp::RNG &rng, bool secret) const noexcept;
/*
* @brief Performs DSA signing
*
* @param rng initialized PRNG
* @param sig[out] created signature
* @param hash hash to sign
* @param hash_len length of `hash`
*
* @returns RNP_SUCCESS
* RNP_ERROR_BAD_PARAMETERS wrong input provided
* RNP_ERROR_SIGNING_FAILED internal error
*/
rnp_result_t sign(rnp::RNG &rng, Signature &sig, const rnp::secure_bytes &hash) const;
/*
* @brief Performs DSA verification
*
* @param hash hash to verify
* @param hash_len length of `hash`
* @param sig signature to be verified
*
* @returns RNP_SUCCESS
* RNP_ERROR_BAD_PARAMETERS wrong input provided
* RNP_ERROR_GENERIC internal error
* RNP_ERROR_SIGNATURE_INVALID signature is invalid
*/
rnp_result_t verify(const Signature &sig, const rnp::secure_bytes &hash) const;
/*
* @brief Performs DSA key generation
*
* @param rng initialized PRNG
* @param keylen length of the key, in bits
* @param qbits subgroup size in bits
*
* @returns RNP_SUCCESS
* RNP_ERROR_BAD_PARAMETERS wrong input provided
* RNP_ERROR_OUT_OF_MEMORY memory allocation failed
* RNP_ERROR_GENERIC internal error
*/
rnp_result_t generate(rnp::RNG &rng, size_t keylen, size_t qbits);
/*
* @brief Returns minimally sized hash which will work
* with the DSA subgroup.
*
* @param qsize subgroup order
*
* @returns Either ID of the hash algorithm, or PGP_HASH_UNKNOWN
* if not found
*/
static pgp_hash_alg_t get_min_hash(size_t qsize);
/*
* @brief Helps to determine subgroup size by size of p
* In order not to confuse users, we use less complicated
* approach than suggested by FIPS-186, which is:
* p=1024 => q=160
* p<2048 => q=224
* p<=3072 => q=256
* So we don't generate (2048, 224) pair
*
* @return Size of `q' or 0 in case `psize' is not in <1024,3072> range
*/
static size_t choose_qsize(size_t psize);
};
} // namespace dsa
} // namespace pgp
#endif