openssl/crypto/ffc/ffc_params_validate.c
Shane Lontis 8083fd3a18 Add FFC param/key validation
Embed libctx in dsa and dh objects and cleanup internal methods to not pass libctx (This makes it consistent with the rsa changes)

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10910)
2020-02-16 13:03:46 +10:00

81 lines
2.7 KiB
C

/*
* Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
/*
* Finite Field cryptography (FFC) is used for DSA and DH.
* This file contains methods for validation of FFC parameters.
* It calls the same functions as the generation as the code is very similar.
*/
#include "internal/ffc.h"
/* FIPS186-4 A.2.2 Unverifiable partial validation of Generator g */
int ffc_params_validate_unverifiable_g(BN_CTX *ctx, BN_MONT_CTX *mont,
const BIGNUM *p, const BIGNUM *q,
const BIGNUM *g, BIGNUM *tmp, int *ret)
{
/*
* A.2.2 Step (1) AND
* A.2.4 Step (2)
* Verify that 2 <= g <= (p - 1)
*/
if (BN_cmp(g, BN_value_one()) <= 0 || BN_cmp(g, p) >= 0) {
*ret |= FFC_ERROR_NOT_SUITABLE_GENERATOR;
return 0;
}
/*
* A.2.2 Step (2) AND
* A.2.4 Step (3)
* Check g^q mod p = 1
*/
if (!BN_mod_exp_mont(tmp, g, q, p, ctx, mont))
return 0;
if (BN_cmp(tmp, BN_value_one()) != 0) {
*ret |= FFC_ERROR_NOT_SUITABLE_GENERATOR;
return 0;
}
return 1;
}
int ffc_params_FIPS186_4_validate(const FFC_PARAMS *params, int type,
const EVP_MD *evpmd, int validate_flags,
int *res, BN_GENCB *cb)
{
size_t L, N;
if (params == NULL || params->p == NULL || params->q == NULL)
return FFC_PARAMS_RET_STATUS_FAILED;
/* A.1.1.3 Step (1..2) : L = len(p), N = len(q) */
L = BN_num_bits(params->p);
N = BN_num_bits(params->q);
return ffc_params_FIPS186_4_gen_verify(NULL, (FFC_PARAMS *)params, type, L, N,
evpmd, validate_flags, res, cb);
}
/* This may be used in FIPS mode to validate deprecated FIPS-186-2 Params */
int ffc_params_FIPS186_2_validate(const FFC_PARAMS *params, int type,
const EVP_MD *evpmd, int validate_flags,
int *res, BN_GENCB *cb)
{
size_t L, N;
if (params->p == NULL || params->q == NULL) {
*res = FFC_CHECK_INVALID_PQ;
return FFC_PARAMS_RET_STATUS_FAILED;
}
/* A.1.1.3 Step (1..2) : L = len(p), N = len(q) */
L = BN_num_bits(params->p);
N = BN_num_bits(params->q);
return ffc_params_FIPS186_2_gen_verify(NULL, (FFC_PARAMS *)params, type, L, N,
evpmd, validate_flags, res, cb);
}