ref: 8bc69a872883224675a55db51ac8f60ab5ed9e5a
dir: /third_party/boringssl/src/crypto/evp/p_dsa_asn1.c/
/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
* 2006.
*/
/* ====================================================================
* Copyright (c) 2006 The OpenSSL Project. 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.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* licensing@OpenSSL.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED 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 OpenSSL PROJECT OR
* ITS 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.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com). */
#include <openssl/evp.h>
#include <openssl/digest.h>
#include <openssl/bn.h>
#include <openssl/bytestring.h>
#include <openssl/dsa.h>
#include <openssl/err.h>
#include "internal.h"
static int dsa_pub_decode(EVP_PKEY *out, CBS *params, CBS *key) {
// See RFC 3279, section 2.3.2.
// Parameters may or may not be present.
DSA *dsa;
if (CBS_len(params) == 0) {
dsa = DSA_new();
if (dsa == NULL) {
return 0;
}
} else {
dsa = DSA_parse_parameters(params);
if (dsa == NULL || CBS_len(params) != 0) {
OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
goto err;
}
}
dsa->pub_key = BN_new();
if (dsa->pub_key == NULL) {
goto err;
}
if (!BN_parse_asn1_unsigned(key, dsa->pub_key) ||
CBS_len(key) != 0) {
OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
goto err;
}
EVP_PKEY_assign_DSA(out, dsa);
return 1;
err:
DSA_free(dsa);
return 0;
}
static int dsa_pub_encode(CBB *out, const EVP_PKEY *key) {
const DSA *dsa = key->pkey.dsa;
const int has_params = dsa->p != NULL && dsa->q != NULL && dsa->g != NULL;
// See RFC 5480, section 2.
CBB spki, algorithm, oid, key_bitstring;
if (!CBB_add_asn1(out, &spki, CBS_ASN1_SEQUENCE) ||
!CBB_add_asn1(&spki, &algorithm, CBS_ASN1_SEQUENCE) ||
!CBB_add_asn1(&algorithm, &oid, CBS_ASN1_OBJECT) ||
!CBB_add_bytes(&oid, dsa_asn1_meth.oid, dsa_asn1_meth.oid_len) ||
(has_params &&
!DSA_marshal_parameters(&algorithm, dsa)) ||
!CBB_add_asn1(&spki, &key_bitstring, CBS_ASN1_BITSTRING) ||
!CBB_add_u8(&key_bitstring, 0 /* padding */) ||
!BN_marshal_asn1(&key_bitstring, dsa->pub_key) ||
!CBB_flush(out)) {
OPENSSL_PUT_ERROR(EVP, EVP_R_ENCODE_ERROR);
return 0;
}
return 1;
}
static int dsa_priv_decode(EVP_PKEY *out, CBS *params, CBS *key) {
// See PKCS#11, v2.40, section 2.5.
// Decode parameters.
BN_CTX *ctx = NULL;
DSA *dsa = DSA_parse_parameters(params);
if (dsa == NULL || CBS_len(params) != 0) {
OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
goto err;
}
dsa->priv_key = BN_new();
dsa->pub_key = BN_new();
if (dsa->priv_key == NULL || dsa->pub_key == NULL) {
goto err;
}
// Decode the key. To avoid DoS attacks when importing private keys, we bound
// |dsa->priv_key| against |dsa->q|, which itself bound by
// |DSA_parse_parameters|. (We cannot call |BN_num_bits| on |dsa->priv_key|.
// That would leak a secret bit width.)
if (!BN_parse_asn1_unsigned(key, dsa->priv_key) ||
CBS_len(key) != 0 ||
BN_cmp(dsa->priv_key, dsa->q) >= 0) {
OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
goto err;
}
// Calculate the public key.
ctx = BN_CTX_new();
if (ctx == NULL ||
!BN_mod_exp_mont_consttime(dsa->pub_key, dsa->g, dsa->priv_key, dsa->p,
ctx, NULL)) {
goto err;
}
BN_CTX_free(ctx);
EVP_PKEY_assign_DSA(out, dsa);
return 1;
err:
BN_CTX_free(ctx);
DSA_free(dsa);
return 0;
}
static int dsa_priv_encode(CBB *out, const EVP_PKEY *key) {
const DSA *dsa = key->pkey.dsa;
if (dsa == NULL || dsa->priv_key == NULL) {
OPENSSL_PUT_ERROR(EVP, EVP_R_MISSING_PARAMETERS);
return 0;
}
// See PKCS#11, v2.40, section 2.5.
CBB pkcs8, algorithm, oid, private_key;
if (!CBB_add_asn1(out, &pkcs8, CBS_ASN1_SEQUENCE) ||
!CBB_add_asn1_uint64(&pkcs8, 0 /* version */) ||
!CBB_add_asn1(&pkcs8, &algorithm, CBS_ASN1_SEQUENCE) ||
!CBB_add_asn1(&algorithm, &oid, CBS_ASN1_OBJECT) ||
!CBB_add_bytes(&oid, dsa_asn1_meth.oid, dsa_asn1_meth.oid_len) ||
!DSA_marshal_parameters(&algorithm, dsa) ||
!CBB_add_asn1(&pkcs8, &private_key, CBS_ASN1_OCTETSTRING) ||
!BN_marshal_asn1(&private_key, dsa->priv_key) ||
!CBB_flush(out)) {
OPENSSL_PUT_ERROR(EVP, EVP_R_ENCODE_ERROR);
return 0;
}
return 1;
}
static int int_dsa_size(const EVP_PKEY *pkey) {
return DSA_size(pkey->pkey.dsa);
}
static int dsa_bits(const EVP_PKEY *pkey) {
return BN_num_bits(pkey->pkey.dsa->p);
}
static int dsa_missing_parameters(const EVP_PKEY *pkey) {
DSA *dsa;
dsa = pkey->pkey.dsa;
if (dsa->p == NULL || dsa->q == NULL || dsa->g == NULL) {
return 1;
}
return 0;
}
static int dup_bn_into(BIGNUM **out, BIGNUM *src) {
BIGNUM *a;
a = BN_dup(src);
if (a == NULL) {
return 0;
}
BN_free(*out);
*out = a;
return 1;
}
static int dsa_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from) {
if (!dup_bn_into(&to->pkey.dsa->p, from->pkey.dsa->p) ||
!dup_bn_into(&to->pkey.dsa->q, from->pkey.dsa->q) ||
!dup_bn_into(&to->pkey.dsa->g, from->pkey.dsa->g)) {
return 0;
}
return 1;
}
static int dsa_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b) {
return BN_cmp(a->pkey.dsa->p, b->pkey.dsa->p) == 0 &&
BN_cmp(a->pkey.dsa->q, b->pkey.dsa->q) == 0 &&
BN_cmp(a->pkey.dsa->g, b->pkey.dsa->g) == 0;
}
static int dsa_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b) {
return BN_cmp(b->pkey.dsa->pub_key, a->pkey.dsa->pub_key) == 0;
}
static void int_dsa_free(EVP_PKEY *pkey) { DSA_free(pkey->pkey.dsa); }
const EVP_PKEY_ASN1_METHOD dsa_asn1_meth = {
EVP_PKEY_DSA,
// 1.2.840.10040.4.1
{0x2a, 0x86, 0x48, 0xce, 0x38, 0x04, 0x01}, 7,
dsa_pub_decode,
dsa_pub_encode,
dsa_pub_cmp,
dsa_priv_decode,
dsa_priv_encode,
NULL /* set_priv_raw */,
NULL /* set_pub_raw */,
NULL /* get_priv_raw */,
NULL /* get_pub_raw */,
NULL /* pkey_opaque */,
int_dsa_size,
dsa_bits,
dsa_missing_parameters,
dsa_copy_parameters,
dsa_cmp_parameters,
int_dsa_free,
};