ref: 94f2907dc40a6415a10c252cb9ba3971f1f7e838
dir: /third_party/boringssl/src/crypto/ecdsa_extra/ecdsa_asn1.c/
/* ====================================================================
* Copyright (c) 1998-2005 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
* [email protected].
*
* 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
* ([email protected]). This product includes software written by Tim
* Hudson ([email protected]). */
#include <openssl/ecdsa.h>
#include <limits.h>
#include <string.h>
#include <openssl/bn.h>
#include <openssl/bytestring.h>
#include <openssl/err.h>
#include <openssl/ec_key.h>
#include <openssl/mem.h>
#include "../bytestring/internal.h"
#include "../fipsmodule/ecdsa/internal.h"
#include "../internal.h"
static ECDSA_SIG *ecdsa_sig_from_fixed(const EC_KEY *key, const uint8_t *in,
size_t len) {
const EC_GROUP *group = EC_KEY_get0_group(key);
if (group == NULL) {
OPENSSL_PUT_ERROR(ECDSA, ERR_R_PASSED_NULL_PARAMETER);
return NULL;
}
size_t scalar_len = BN_num_bytes(EC_GROUP_get0_order(group));
if (len != 2 * scalar_len) {
OPENSSL_PUT_ERROR(ECDSA, ECDSA_R_BAD_SIGNATURE);
return NULL;
}
ECDSA_SIG *ret = ECDSA_SIG_new();
if (ret == NULL ||
!BN_bin2bn(in, scalar_len, ret->r) ||
!BN_bin2bn(in + scalar_len, scalar_len, ret->s)) {
ECDSA_SIG_free(ret);
return NULL;
}
return ret;
}
static int ecdsa_sig_to_fixed(const EC_KEY *key, uint8_t *out, size_t *out_len,
size_t max_out, const ECDSA_SIG *sig) {
const EC_GROUP *group = EC_KEY_get0_group(key);
if (group == NULL) {
OPENSSL_PUT_ERROR(ECDSA, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
size_t scalar_len = BN_num_bytes(EC_GROUP_get0_order(group));
if (max_out < 2 * scalar_len) {
OPENSSL_PUT_ERROR(EC, EC_R_BUFFER_TOO_SMALL);
return 0;
}
if (BN_is_negative(sig->r) ||
!BN_bn2bin_padded(out, scalar_len, sig->r) ||
BN_is_negative(sig->s) ||
!BN_bn2bin_padded(out + scalar_len, scalar_len, sig->s)) {
OPENSSL_PUT_ERROR(ECDSA, ECDSA_R_BAD_SIGNATURE);
return 0;
}
*out_len = 2 * scalar_len;
return 1;
}
int ECDSA_sign(int type, const uint8_t *digest, size_t digest_len, uint8_t *sig,
unsigned int *out_sig_len, const EC_KEY *eckey) {
if (eckey->ecdsa_meth && eckey->ecdsa_meth->sign) {
return eckey->ecdsa_meth->sign(digest, digest_len, sig, out_sig_len,
(EC_KEY*) eckey /* cast away const */);
}
*out_sig_len = 0;
uint8_t fixed[ECDSA_MAX_FIXED_LEN];
size_t fixed_len;
if (!ecdsa_sign_fixed(digest, digest_len, fixed, &fixed_len, sizeof(fixed),
eckey)) {
return 0;
}
// TODO(davidben): We can actually do better and go straight from the DER
// format to the fixed-width format without a malloc.
ECDSA_SIG *s = ecdsa_sig_from_fixed(eckey, fixed, fixed_len);
if (s == NULL) {
return 0;
}
int ret = 0;
CBB cbb;
CBB_init_fixed(&cbb, sig, ECDSA_size(eckey));
size_t len;
if (!ECDSA_SIG_marshal(&cbb, s) ||
!CBB_finish(&cbb, NULL, &len)) {
OPENSSL_PUT_ERROR(ECDSA, ECDSA_R_ENCODE_ERROR);
goto err;
}
*out_sig_len = (unsigned)len;
ret = 1;
err:
ECDSA_SIG_free(s);
return ret;
}
int ECDSA_verify(int type, const uint8_t *digest, size_t digest_len,
const uint8_t *sig, size_t sig_len, const EC_KEY *eckey) {
// Decode the ECDSA signature.
//
// TODO(davidben): We can actually do better and go straight from the DER
// format to the fixed-width format without a malloc.
int ret = 0;
uint8_t *der = NULL;
ECDSA_SIG *s = ECDSA_SIG_from_bytes(sig, sig_len);
if (s == NULL) {
goto err;
}
// Defend against potential laxness in the DER parser.
size_t der_len;
if (!ECDSA_SIG_to_bytes(&der, &der_len, s) ||
der_len != sig_len || OPENSSL_memcmp(sig, der, sig_len) != 0) {
// This should never happen. crypto/bytestring is strictly DER.
OPENSSL_PUT_ERROR(ECDSA, ERR_R_INTERNAL_ERROR);
goto err;
}
uint8_t fixed[ECDSA_MAX_FIXED_LEN];
size_t fixed_len;
ret = ecdsa_sig_to_fixed(eckey, fixed, &fixed_len, sizeof(fixed), s) &&
ecdsa_verify_fixed(digest, digest_len, fixed, fixed_len, eckey);
err:
OPENSSL_free(der);
ECDSA_SIG_free(s);
return ret;
}
size_t ECDSA_size(const EC_KEY *key) {
if (key == NULL) {
return 0;
}
size_t group_order_size;
if (key->ecdsa_meth && key->ecdsa_meth->group_order_size) {
group_order_size = key->ecdsa_meth->group_order_size(key);
} else {
const EC_GROUP *group = EC_KEY_get0_group(key);
if (group == NULL) {
return 0;
}
group_order_size = BN_num_bytes(EC_GROUP_get0_order(group));
}
return ECDSA_SIG_max_len(group_order_size);
}
ECDSA_SIG *ECDSA_SIG_new(void) {
ECDSA_SIG *sig = OPENSSL_malloc(sizeof(ECDSA_SIG));
if (sig == NULL) {
return NULL;
}
sig->r = BN_new();
sig->s = BN_new();
if (sig->r == NULL || sig->s == NULL) {
ECDSA_SIG_free(sig);
return NULL;
}
return sig;
}
void ECDSA_SIG_free(ECDSA_SIG *sig) {
if (sig == NULL) {
return;
}
BN_free(sig->r);
BN_free(sig->s);
OPENSSL_free(sig);
}
const BIGNUM *ECDSA_SIG_get0_r(const ECDSA_SIG *sig) {
return sig->r;
}
const BIGNUM *ECDSA_SIG_get0_s(const ECDSA_SIG *sig) {
return sig->s;
}
void ECDSA_SIG_get0(const ECDSA_SIG *sig, const BIGNUM **out_r,
const BIGNUM **out_s) {
if (out_r != NULL) {
*out_r = sig->r;
}
if (out_s != NULL) {
*out_s = sig->s;
}
}
int ECDSA_SIG_set0(ECDSA_SIG *sig, BIGNUM *r, BIGNUM *s) {
if (r == NULL || s == NULL) {
return 0;
}
BN_free(sig->r);
BN_free(sig->s);
sig->r = r;
sig->s = s;
return 1;
}
int ECDSA_do_verify(const uint8_t *digest, size_t digest_len,
const ECDSA_SIG *sig, const EC_KEY *eckey) {
uint8_t fixed[ECDSA_MAX_FIXED_LEN];
size_t fixed_len;
return ecdsa_sig_to_fixed(eckey, fixed, &fixed_len, sizeof(fixed), sig) &&
ecdsa_verify_fixed(digest, digest_len, fixed, fixed_len, eckey);
}
// This function is only exported for testing and is not called in production
// code.
ECDSA_SIG *ECDSA_sign_with_nonce_and_leak_private_key_for_testing(
const uint8_t *digest, size_t digest_len, const EC_KEY *eckey,
const uint8_t *nonce, size_t nonce_len) {
uint8_t sig[ECDSA_MAX_FIXED_LEN];
size_t sig_len;
if (!ecdsa_sign_fixed_with_nonce_for_known_answer_test(
digest, digest_len, sig, &sig_len, sizeof(sig), eckey, nonce,
nonce_len)) {
return NULL;
}
return ecdsa_sig_from_fixed(eckey, sig, sig_len);
}
ECDSA_SIG *ECDSA_do_sign(const uint8_t *digest, size_t digest_len,
const EC_KEY *eckey) {
uint8_t sig[ECDSA_MAX_FIXED_LEN];
size_t sig_len;
if (!ecdsa_sign_fixed(digest, digest_len, sig, &sig_len, sizeof(sig),
eckey)) {
return NULL;
}
return ecdsa_sig_from_fixed(eckey, sig, sig_len);
}
ECDSA_SIG *ECDSA_SIG_parse(CBS *cbs) {
ECDSA_SIG *ret = ECDSA_SIG_new();
if (ret == NULL) {
return NULL;
}
CBS child;
if (!CBS_get_asn1(cbs, &child, CBS_ASN1_SEQUENCE) ||
!BN_parse_asn1_unsigned(&child, ret->r) ||
!BN_parse_asn1_unsigned(&child, ret->s) ||
CBS_len(&child) != 0) {
OPENSSL_PUT_ERROR(ECDSA, ECDSA_R_BAD_SIGNATURE);
ECDSA_SIG_free(ret);
return NULL;
}
return ret;
}
ECDSA_SIG *ECDSA_SIG_from_bytes(const uint8_t *in, size_t in_len) {
CBS cbs;
CBS_init(&cbs, in, in_len);
ECDSA_SIG *ret = ECDSA_SIG_parse(&cbs);
if (ret == NULL || CBS_len(&cbs) != 0) {
OPENSSL_PUT_ERROR(ECDSA, ECDSA_R_BAD_SIGNATURE);
ECDSA_SIG_free(ret);
return NULL;
}
return ret;
}
int ECDSA_SIG_marshal(CBB *cbb, const ECDSA_SIG *sig) {
CBB child;
if (!CBB_add_asn1(cbb, &child, CBS_ASN1_SEQUENCE) ||
!BN_marshal_asn1(&child, sig->r) ||
!BN_marshal_asn1(&child, sig->s) ||
!CBB_flush(cbb)) {
OPENSSL_PUT_ERROR(ECDSA, ECDSA_R_ENCODE_ERROR);
return 0;
}
return 1;
}
int ECDSA_SIG_to_bytes(uint8_t **out_bytes, size_t *out_len,
const ECDSA_SIG *sig) {
CBB cbb;
CBB_zero(&cbb);
if (!CBB_init(&cbb, 0) ||
!ECDSA_SIG_marshal(&cbb, sig) ||
!CBB_finish(&cbb, out_bytes, out_len)) {
OPENSSL_PUT_ERROR(ECDSA, ECDSA_R_ENCODE_ERROR);
CBB_cleanup(&cbb);
return 0;
}
return 1;
}
// der_len_len returns the number of bytes needed to represent a length of |len|
// in DER.
static size_t der_len_len(size_t len) {
if (len < 0x80) {
return 1;
}
size_t ret = 1;
while (len > 0) {
ret++;
len >>= 8;
}
return ret;
}
size_t ECDSA_SIG_max_len(size_t order_len) {
// Compute the maximum length of an |order_len| byte integer. Defensively
// assume that the leading 0x00 is included.
size_t integer_len = 1 /* tag */ + der_len_len(order_len + 1) + 1 + order_len;
if (integer_len < order_len) {
return 0;
}
// An ECDSA signature is two INTEGERs.
size_t value_len = 2 * integer_len;
if (value_len < integer_len) {
return 0;
}
// Add the header.
size_t ret = 1 /* tag */ + der_len_len(value_len) + value_len;
if (ret < value_len) {
return 0;
}
return ret;
}
ECDSA_SIG *d2i_ECDSA_SIG(ECDSA_SIG **out, const uint8_t **inp, long len) {
if (len < 0) {
return NULL;
}
CBS cbs;
CBS_init(&cbs, *inp, (size_t)len);
ECDSA_SIG *ret = ECDSA_SIG_parse(&cbs);
if (ret == NULL) {
return NULL;
}
if (out != NULL) {
ECDSA_SIG_free(*out);
*out = ret;
}
*inp = CBS_data(&cbs);
return ret;
}
int i2d_ECDSA_SIG(const ECDSA_SIG *sig, uint8_t **outp) {
CBB cbb;
if (!CBB_init(&cbb, 0) ||
!ECDSA_SIG_marshal(&cbb, sig)) {
CBB_cleanup(&cbb);
return -1;
}
return CBB_finish_i2d(&cbb, outp);
}