rsa_backend.c
/*
* Copyright 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
*/
#include <string.h>
#include <openssl/core_names.h>
#include <openssl/params.h>
#include <openssl/evp.h>
#include "internal/sizes.h"
#include "internal/param_build_set.h"
#include "crypto/rsa.h"
#include "e_os.h" /* strcasecmp for Windows() */
/*
* The intention with the "backend" source file is to offer backend support
* for legacy backends (EVP_PKEY_ASN1_METHOD and EVP_PKEY_METHOD) and provider
* implementations alike.
*/
DEFINE_STACK_OF(BIGNUM)
static int collect_numbers(STACK_OF(BIGNUM) *numbers,
const OSSL_PARAM params[], const char *names[])
{
const OSSL_PARAM *p = NULL;
int i;
if (numbers == NULL)
return 0;
for (i = 0; names[i] != NULL; i++){
p = OSSL_PARAM_locate_const(params, names[i]);
if (p != NULL) {
BIGNUM *tmp = NULL;
if (!OSSL_PARAM_get_BN(p, &tmp)
|| sk_BIGNUM_push(numbers, tmp) == 0)
return 0;
}
}
return 1;
}
int ossl_rsa_fromdata(RSA *rsa, const OSSL_PARAM params[])
{
const OSSL_PARAM *param_n, *param_e, *param_d;
BIGNUM *n = NULL, *e = NULL, *d = NULL;
STACK_OF(BIGNUM) *factors = NULL, *exps = NULL, *coeffs = NULL;
int is_private = 0;
if (rsa == NULL)
return 0;
param_n = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_N);
param_e = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_E);
param_d = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_D);
if ((param_n != NULL && !OSSL_PARAM_get_BN(param_n, &n))
|| (param_e != NULL && !OSSL_PARAM_get_BN(param_e, &e))
|| (param_d != NULL && !OSSL_PARAM_get_BN(param_d, &d)))
goto err;
is_private = (d != NULL);
if (!RSA_set0_key(rsa, n, e, d))
goto err;
n = e = d = NULL;
if (is_private) {
if (!collect_numbers(factors = sk_BIGNUM_new_null(), params,
ossl_rsa_mp_factor_names)
|| !collect_numbers(exps = sk_BIGNUM_new_null(), params,
ossl_rsa_mp_exp_names)
|| !collect_numbers(coeffs = sk_BIGNUM_new_null(), params,
ossl_rsa_mp_coeff_names))
goto err;
/* It's ok if this private key just has n, e and d */
if (sk_BIGNUM_num(factors) != 0
&& !ossl_rsa_set0_all_params(rsa, factors, exps, coeffs))
goto err;
}
sk_BIGNUM_free(factors);
sk_BIGNUM_free(exps);
sk_BIGNUM_free(coeffs);
return 1;
err:
BN_free(n);
BN_free(e);
BN_free(d);
sk_BIGNUM_pop_free(factors, BN_free);
sk_BIGNUM_pop_free(exps, BN_free);
sk_BIGNUM_pop_free(coeffs, BN_free);
return 0;
}
DEFINE_SPECIAL_STACK_OF_CONST(BIGNUM_const, BIGNUM)
int ossl_rsa_todata(RSA *rsa, OSSL_PARAM_BLD *bld, OSSL_PARAM params[])
{
int ret = 0;
const BIGNUM *rsa_d = NULL, *rsa_n = NULL, *rsa_e = NULL;
STACK_OF(BIGNUM_const) *factors = sk_BIGNUM_const_new_null();
STACK_OF(BIGNUM_const) *exps = sk_BIGNUM_const_new_null();
STACK_OF(BIGNUM_const) *coeffs = sk_BIGNUM_const_new_null();
if (rsa == NULL || factors == NULL || exps == NULL || coeffs == NULL)
goto err;
RSA_get0_key(rsa, &rsa_n, &rsa_e, &rsa_d);
ossl_rsa_get0_all_params(rsa, factors, exps, coeffs);
if (!ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_N, rsa_n)
|| !ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_E, rsa_e))
goto err;
/* Check private key data integrity */
if (rsa_d != NULL) {
int numprimes = sk_BIGNUM_const_num(factors);
int numexps = sk_BIGNUM_const_num(exps);
int numcoeffs = sk_BIGNUM_const_num(coeffs);
/*
* It's permissible to have zero primes, i.e. no CRT params.
* Otherwise, there must be at least two, as many exponents,
* and one coefficient less.
*/
if (numprimes != 0
&& (numprimes < 2 || numexps < 2 || numcoeffs < 1))
goto err;
if (!ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_D,
rsa_d)
|| !ossl_param_build_set_multi_key_bn(bld, params,
ossl_rsa_mp_factor_names,
factors)
|| !ossl_param_build_set_multi_key_bn(bld, params,
ossl_rsa_mp_exp_names, exps)
|| !ossl_param_build_set_multi_key_bn(bld, params,
ossl_rsa_mp_coeff_names,
coeffs))
goto err;
}
#if defined(FIPS_MODULE) && !defined(OPENSSL_NO_ACVP_TESTS)
/* The acvp test results are not meant for export so check for bld == NULL */
if (bld == NULL)
rsa_acvp_test_get_params(rsa, params);
#endif
ret = 1;
err:
sk_BIGNUM_const_free(factors);
sk_BIGNUM_const_free(exps);
sk_BIGNUM_const_free(coeffs);
return ret;
}
int ossl_rsa_pss_params_30_todata(const RSA_PSS_PARAMS_30 *pss,
OSSL_PARAM_BLD *bld, OSSL_PARAM params[])
{
if (!ossl_rsa_pss_params_30_is_unrestricted(pss)) {
int hashalg_nid = ossl_rsa_pss_params_30_hashalg(pss);
int maskgenalg_nid = ossl_rsa_pss_params_30_maskgenalg(pss);
int maskgenhashalg_nid = ossl_rsa_pss_params_30_maskgenhashalg(pss);
int saltlen = ossl_rsa_pss_params_30_saltlen(pss);
int default_hashalg_nid = ossl_rsa_pss_params_30_hashalg(NULL);
int default_maskgenalg_nid = ossl_rsa_pss_params_30_maskgenalg(NULL);
int default_maskgenhashalg_nid =
ossl_rsa_pss_params_30_maskgenhashalg(NULL);
const char *mdname =
(hashalg_nid == default_hashalg_nid
? NULL : ossl_rsa_oaeppss_nid2name(hashalg_nid));
const char *mgfname =
(maskgenalg_nid == default_maskgenalg_nid
? NULL : ossl_rsa_oaeppss_nid2name(maskgenalg_nid));
const char *mgf1mdname =
(maskgenhashalg_nid == default_maskgenhashalg_nid
? NULL : ossl_rsa_oaeppss_nid2name(maskgenhashalg_nid));
const char *key_md = OSSL_PKEY_PARAM_RSA_DIGEST;
const char *key_mgf = OSSL_PKEY_PARAM_RSA_MASKGENFUNC;
const char *key_mgf1_md = OSSL_PKEY_PARAM_RSA_MGF1_DIGEST;
const char *key_saltlen = OSSL_PKEY_PARAM_RSA_PSS_SALTLEN;
/*
* To ensure that the key isn't seen as unrestricted by the recipient,
* we make sure that at least one PSS-related parameter is passed, even
* if it has a default value; saltlen.
*/
if ((mdname != NULL
&& !ossl_param_build_set_utf8_string(bld, params, key_md, mdname))
|| (mgfname != NULL
&& !ossl_param_build_set_utf8_string(bld, params,
key_mgf, mgfname))
|| (mgf1mdname != NULL
&& !ossl_param_build_set_utf8_string(bld, params,
key_mgf1_md, mgf1mdname))
|| (!ossl_param_build_set_int(bld, params, key_saltlen, saltlen)))
return 0;
}
return 1;
}
int ossl_rsa_pss_params_30_fromdata(RSA_PSS_PARAMS_30 *pss_params,
const OSSL_PARAM params[],
OSSL_LIB_CTX *libctx)
{
const OSSL_PARAM *param_md, *param_mgf, *param_mgf1md, *param_saltlen;
const OSSL_PARAM *param_propq;
const char *propq = NULL;
EVP_MD *md = NULL, *mgf1md = NULL;
int saltlen;
int ret = 0;
if (pss_params == NULL)
return 0;
param_propq =
OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_DIGEST_PROPS);
param_md =
OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_DIGEST);
param_mgf =
OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_MASKGENFUNC);
param_mgf1md =
OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_MGF1_DIGEST);
param_saltlen =
OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_PSS_SALTLEN);
if (param_propq != NULL) {
if (param_propq->data_type == OSSL_PARAM_UTF8_STRING)
propq = param_propq->data;
}
/*
* If we get any of the parameters, we know we have at least some
* restrictions, so we start by setting default values, and let each
* parameter override their specific restriction data.
*/
if (param_md != NULL || param_mgf != NULL || param_mgf1md != NULL
|| param_saltlen != NULL)
if (!ossl_rsa_pss_params_30_set_defaults(pss_params))
return 0;
if (param_mgf != NULL) {
int default_maskgenalg_nid = ossl_rsa_pss_params_30_maskgenalg(NULL);
const char *mgfname = NULL;
if (param_mgf->data_type == OSSL_PARAM_UTF8_STRING)
mgfname = param_mgf->data;
else if (!OSSL_PARAM_get_utf8_ptr(param_mgf, &mgfname))
return 0;
/* TODO Revisit this if / when a new MGF algorithm appears */
if (strcasecmp(param_mgf->data,
ossl_rsa_mgf_nid2name(default_maskgenalg_nid)) != 0)
return 0;
}
/*
* We're only interested in the NIDs that correspond to the MDs, so the
* exact propquery is unimportant in the EVP_MD_fetch() calls below.
*/
if (param_md != NULL) {
const char *mdname = NULL;
if (param_md->data_type == OSSL_PARAM_UTF8_STRING)
mdname = param_md->data;
else if (!OSSL_PARAM_get_utf8_ptr(param_mgf, &mdname))
goto err;
if ((md = EVP_MD_fetch(libctx, mdname, propq)) == NULL
|| !ossl_rsa_pss_params_30_set_hashalg(pss_params,
ossl_rsa_oaeppss_md2nid(md)))
goto err;
}
if (param_mgf1md != NULL) {
const char *mgf1mdname = NULL;
if (param_mgf1md->data_type == OSSL_PARAM_UTF8_STRING)
mgf1mdname = param_mgf1md->data;
else if (!OSSL_PARAM_get_utf8_ptr(param_mgf, &mgf1mdname))
goto err;
if ((mgf1md = EVP_MD_fetch(libctx, mgf1mdname, propq)) == NULL
|| !ossl_rsa_pss_params_30_set_maskgenhashalg(
pss_params, ossl_rsa_oaeppss_md2nid(mgf1md)))
goto err;
}
if (param_saltlen != NULL) {
if (!OSSL_PARAM_get_int(param_saltlen, &saltlen)
|| !ossl_rsa_pss_params_30_set_saltlen(pss_params, saltlen))
goto err;
}
ret = 1;
err:
EVP_MD_free(md);
EVP_MD_free(mgf1md);
return ret;
}
