openssl/crypto/dsa/dsa_backend.c
Richard Levitte cf33379997 PROV: Add type specific PKCS#8 decoding to the DER->key decoders
This required refactoring a number of functions from the diverse
EVP_PKEY_ASN1_METHOD implementations to become shared backend
functions.  It also meant modifying a few of them to return pointers
to our internal RSA / DSA/ DH / EC_KEY, ... structures instead of
manipulating an EVP_PKEY pointer directly, letting the caller do the
latter.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/14314)
2021-03-19 16:46:39 +01:00

130 lines
3.5 KiB
C

/*
* Copyright 2020-2021 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
*/
/*
* DSA low level APIs are deprecated for public use, but still ok for
* internal use.
*/
#include "internal/deprecated.h"
#include <openssl/core_names.h>
#include <openssl/err.h>
#include "crypto/dsa.h"
/*
* 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.
*/
int ossl_dsa_key_fromdata(DSA *dsa, const OSSL_PARAM params[])
{
const OSSL_PARAM *param_priv_key, *param_pub_key;
BIGNUM *priv_key = NULL, *pub_key = NULL;
if (dsa == NULL)
return 0;
param_priv_key =
OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PRIV_KEY);
param_pub_key =
OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PUB_KEY);
/* It's ok if neither half is present */
if (param_priv_key == NULL && param_pub_key == NULL)
return 1;
if (param_pub_key != NULL && !OSSL_PARAM_get_BN(param_pub_key, &pub_key))
goto err;
if (param_priv_key != NULL && !OSSL_PARAM_get_BN(param_priv_key, &priv_key))
goto err;
if (!DSA_set0_key(dsa, pub_key, priv_key))
goto err;
return 1;
err:
BN_clear_free(priv_key);
BN_free(pub_key);
return 0;
}
#ifndef FIPS_MODULE
DSA *ossl_dsa_key_from_pkcs8(const PKCS8_PRIV_KEY_INFO *p8inf,
OSSL_LIB_CTX *libctx, const char *propq)
{
const unsigned char *p, *pm;
int pklen, pmlen;
int ptype;
const void *pval;
const ASN1_STRING *pstr;
const X509_ALGOR *palg;
ASN1_INTEGER *privkey = NULL;
const BIGNUM *dsa_p, *dsa_g;
BIGNUM *dsa_pubkey = NULL, *dsa_privkey = NULL;
BN_CTX *ctx = NULL;
DSA *dsa = NULL;
if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8inf))
return 0;
X509_ALGOR_get0(NULL, &ptype, &pval, palg);
if ((privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL)
goto decerr;
if (privkey->type == V_ASN1_NEG_INTEGER || ptype != V_ASN1_SEQUENCE)
goto decerr;
pstr = pval;
pm = pstr->data;
pmlen = pstr->length;
if ((dsa = d2i_DSAparams(NULL, &pm, pmlen)) == NULL)
goto decerr;
/* We have parameters now set private key */
if ((dsa_privkey = BN_secure_new()) == NULL
|| !ASN1_INTEGER_to_BN(privkey, dsa_privkey)) {
ERR_raise(ERR_LIB_DSA, DSA_R_BN_ERROR);
goto dsaerr;
}
/* Calculate public key */
if ((dsa_pubkey = BN_new()) == NULL) {
ERR_raise(ERR_LIB_DSA, ERR_R_MALLOC_FAILURE);
goto dsaerr;
}
if ((ctx = BN_CTX_new()) == NULL) {
ERR_raise(ERR_LIB_DSA, ERR_R_MALLOC_FAILURE);
goto dsaerr;
}
dsa_p = DSA_get0_p(dsa);
dsa_g = DSA_get0_g(dsa);
BN_set_flags(dsa_privkey, BN_FLG_CONSTTIME);
if (!BN_mod_exp(dsa_pubkey, dsa_g, dsa_privkey, dsa_p, ctx)) {
ERR_raise(ERR_LIB_DSA, DSA_R_BN_ERROR);
goto dsaerr;
}
DSA_set0_key(dsa, dsa_pubkey, dsa_privkey);
goto done;
decerr:
ERR_raise(ERR_LIB_DSA, DSA_R_DECODE_ERROR);
dsaerr:
BN_free(dsa_privkey);
BN_free(dsa_pubkey);
DSA_free(dsa);
dsa = NULL;
done:
BN_CTX_free(ctx);
ASN1_STRING_clear_free(privkey);
return dsa;
}
#endif