openssl/crypto/sm2/sm2_za.c
Jack Lloyd e425f90fff Make SM2 functions private
Address issue #5670

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6386)
2018-06-04 11:59:40 +01:00

132 lines
3.4 KiB
C

/*
* Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.
* Copyright 2017 Ribose Inc. All Rights Reserved.
* Ported from Ribose contributions from Botan.
*
* Licensed under the OpenSSL license (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 "internal/sm2.h"
#include <openssl/evp.h>
#include <openssl/bn.h>
#include <string.h>
int SM2_compute_userid_digest(uint8_t *out,
const EVP_MD *digest,
const char *user_id,
const EC_KEY *key)
{
int rc = 0;
const EC_GROUP *group = EC_KEY_get0_group(key);
BN_CTX *ctx = NULL;
EVP_MD_CTX *hash = NULL;
BIGNUM *p = NULL;
BIGNUM *a = NULL;
BIGNUM *b = NULL;
BIGNUM *xG = NULL;
BIGNUM *yG = NULL;
BIGNUM *xA = NULL;
BIGNUM *yA = NULL;
int p_bytes = 0;
uint8_t *buf = NULL;
size_t uid_len = 0;
uint16_t entla = 0;
uint8_t e_byte = 0;
hash = EVP_MD_CTX_new();
if (hash == NULL)
goto done;
ctx = BN_CTX_new();
if (ctx == NULL)
goto done;
p = BN_CTX_get(ctx);
a = BN_CTX_get(ctx);
b = BN_CTX_get(ctx);
xG = BN_CTX_get(ctx);
yG = BN_CTX_get(ctx);
xA = BN_CTX_get(ctx);
yA = BN_CTX_get(ctx);
if (p == NULL || a == NULL || b == NULL ||
xG == NULL || yG == NULL || xA == NULL || yA == NULL)
goto done;
memset(out, 0, EVP_MD_size(digest));
if (EVP_DigestInit(hash, digest) == 0)
goto done;
/*
ZA=H256(ENTLA || IDA || a || b || xG || yG || xA || yA)
*/
uid_len = strlen(user_id);
if (uid_len >= 8192) /* too large */
goto done;
entla = (unsigned short)(8 * uid_len);
e_byte = entla >> 8;
if (EVP_DigestUpdate(hash, &e_byte, 1) == 0)
goto done;
e_byte = entla & 0xFF;
if (EVP_DigestUpdate(hash, &e_byte, 1) == 0)
goto done;
if (EVP_DigestUpdate(hash, user_id, uid_len) == 0)
goto done;
if (EC_GROUP_get_curve_GFp(group, p, a, b, ctx) == 0)
goto done;
p_bytes = BN_num_bytes(p);
buf = OPENSSL_zalloc(p_bytes);
BN_bn2binpad(a, buf, p_bytes);
if (EVP_DigestUpdate(hash, buf, p_bytes) == 0)
goto done;
BN_bn2binpad(b, buf, p_bytes);
if (EVP_DigestUpdate(hash, buf, p_bytes) == 0)
goto done;
EC_POINT_get_affine_coordinates_GFp(group,
EC_GROUP_get0_generator(group),
xG, yG, ctx);
BN_bn2binpad(xG, buf, p_bytes);
if (EVP_DigestUpdate(hash, buf, p_bytes) == 0)
goto done;
BN_bn2binpad(yG, buf, p_bytes);
if (EVP_DigestUpdate(hash, buf, p_bytes) == 0)
goto done;
EC_POINT_get_affine_coordinates_GFp(group,
EC_KEY_get0_public_key(key),
xA, yA, ctx);
BN_bn2binpad(xA, buf, p_bytes);
if (EVP_DigestUpdate(hash, buf, p_bytes) == 0)
goto done;
BN_bn2binpad(yA, buf, p_bytes);
if (EVP_DigestUpdate(hash, buf, p_bytes) == 0)
goto done;
if (EVP_DigestFinal(hash, out, NULL) == 0)
goto done;
rc = 1;
done:
OPENSSL_free(buf);
BN_CTX_free(ctx);
EVP_MD_CTX_free(hash);
return rc;
}