[thirdparty/openssl.git] / crypto / sm2 / sm2_sign.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 "internal/sm2err.h"
#include "internal/ec_int.h" /* ec_group_do_inverse_ord() */
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/bn.h>
#include <string.h>

int sm2_compute_userid_digest(uint8_t *out,
                              const EVP_MD *digest,
                              const uint8_t *id,
                              const size_t id_len,
                              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;
    uint16_t entla = 0;
    uint8_t e_byte = 0;

    hash = EVP_MD_CTX_new();
    ctx = BN_CTX_new();
    if (hash == NULL || ctx == NULL) {
        SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_MALLOC_FAILURE);
        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 (yA == NULL) {
        SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_MALLOC_FAILURE);
        goto done;
    }

    if (!EVP_DigestInit(hash, digest)) {
        SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_EVP_LIB);
        goto done;
    }

    /* Z = SM3(ENTLA || IDA || a || b || xG || yG || xA || yA) */

    if (id_len >= (UINT16_MAX / 8)) {
        /* too large */
        SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, SM2_R_USER_ID_TOO_LARGE);
        goto done;
    }

    entla = (uint16_t)(8 * id_len);

    e_byte = entla >> 8;
    if (!EVP_DigestUpdate(hash, &e_byte, 1)) {
        SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_EVP_LIB);
        goto done;
    }
    e_byte = entla & 0xFF;
    if (!EVP_DigestUpdate(hash, &e_byte, 1)
            || !EVP_DigestUpdate(hash, id, id_len)) {
        SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_EVP_LIB);
        goto done;
    }

    if (!EC_GROUP_get_curve(group, p, a, b, ctx)) {
        SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_EC_LIB);
        goto done;
    }

    p_bytes = BN_num_bytes(p);
    buf = OPENSSL_zalloc(p_bytes);
    if (buf == NULL) {
        SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_MALLOC_FAILURE);
        goto done;
    }

    if (BN_bn2binpad(a, buf, p_bytes) < 0
            || !EVP_DigestUpdate(hash, buf, p_bytes)
            || BN_bn2binpad(b, buf, p_bytes) < 0
            || !EVP_DigestUpdate(hash, buf, p_bytes)
            || !EC_POINT_get_affine_coordinates(group,
                                                EC_GROUP_get0_generator(group),
                                                xG, yG, ctx)
            || BN_bn2binpad(xG, buf, p_bytes) < 0
            || !EVP_DigestUpdate(hash, buf, p_bytes)
            || BN_bn2binpad(yG, buf, p_bytes) < 0
            || !EVP_DigestUpdate(hash, buf, p_bytes)
            || !EC_POINT_get_affine_coordinates(group,
                                                EC_KEY_get0_public_key(key),
                                                xA, yA, ctx)
            || BN_bn2binpad(xA, buf, p_bytes) < 0
            || !EVP_DigestUpdate(hash, buf, p_bytes)
            || BN_bn2binpad(yA, buf, p_bytes) < 0
            || !EVP_DigestUpdate(hash, buf, p_bytes)
            || !EVP_DigestFinal(hash, out, NULL)) {
        SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_INTERNAL_ERROR);
        goto done;
    }

    rc = 1;

 done:
    OPENSSL_free(buf);
    BN_CTX_free(ctx);
    EVP_MD_CTX_free(hash);
    return rc;
}

static BIGNUM *sm2_compute_msg_hash(const EVP_MD *digest,
                                    const EC_KEY *key,
                                    const uint8_t *id,
                                    const size_t id_len,
                                    const uint8_t *msg, size_t msg_len)
{
    EVP_MD_CTX *hash = EVP_MD_CTX_new();
    const int md_size = EVP_MD_size(digest);
    uint8_t *za = NULL;
    BIGNUM *e = NULL;

    if (md_size < 0) {
        SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, SM2_R_INVALID_DIGEST);
        goto done;
    }

    za = OPENSSL_zalloc(md_size);
    if (hash == NULL || za == NULL) {
        SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_MALLOC_FAILURE);
        goto done;
    }

    if (!sm2_compute_userid_digest(za, digest, id, id_len, key)) {
        /* SM2err already called */
        goto done;
    }

    if (!EVP_DigestInit(hash, digest)
            || !EVP_DigestUpdate(hash, za, md_size)
            || !EVP_DigestUpdate(hash, msg, msg_len)
               /* reuse za buffer to hold H(ZA || M) */
            || !EVP_DigestFinal(hash, za, NULL)) {
        SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_EVP_LIB);
        goto done;
    }

    e = BN_bin2bn(za, md_size, NULL);
    if (e == NULL)
        SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_INTERNAL_ERROR);

 done:
    OPENSSL_free(za);
    EVP_MD_CTX_free(hash);
    return e;
}

static ECDSA_SIG *sm2_sig_gen(const EC_KEY *key, const BIGNUM *e)
{
    const BIGNUM *dA = EC_KEY_get0_private_key(key);
    const EC_GROUP *group = EC_KEY_get0_group(key);
    const BIGNUM *order = EC_GROUP_get0_order(group);
    ECDSA_SIG *sig = NULL;
    EC_POINT *kG = NULL;
    BN_CTX *ctx = NULL;
    BIGNUM *k = NULL;
    BIGNUM *rk = NULL;
    BIGNUM *r = NULL;
    BIGNUM *s = NULL;
    BIGNUM *x1 = NULL;
    BIGNUM *tmp = NULL;

    kG = EC_POINT_new(group);
    ctx = BN_CTX_new();
    if (kG == NULL || ctx == NULL) {
        SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
        goto done;
    }

    BN_CTX_start(ctx);
    k = BN_CTX_get(ctx);
    rk = BN_CTX_get(ctx);
    x1 = BN_CTX_get(ctx);
    tmp = BN_CTX_get(ctx);
    if (tmp == NULL) {
        SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
        goto done;
    }

    /*
     * These values are returned and so should not be allocated out of the
     * context
     */
    r = BN_new();
    s = BN_new();

    if (r == NULL || s == NULL) {
        SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
        goto done;
    }

    for (;;) {
        if (!BN_priv_rand_range(k, order)) {
            SM2err(SM2_F_SM2_SIG_GEN, ERR_R_INTERNAL_ERROR);
            goto done;
        }

        if (!EC_POINT_mul(group, kG, k, NULL, NULL, ctx)
                || !EC_POINT_get_affine_coordinates(group, kG, x1, NULL,
                                                    ctx)
                || !BN_mod_add(r, e, x1, order, ctx)) {
            SM2err(SM2_F_SM2_SIG_GEN, ERR_R_INTERNAL_ERROR);
            goto done;
        }

        /* try again if r == 0 or r+k == n */
        if (BN_is_zero(r))
            continue;

        if (!BN_add(rk, r, k)) {
            SM2err(SM2_F_SM2_SIG_GEN, ERR_R_INTERNAL_ERROR);
            goto done;
        }

        if (BN_cmp(rk, order) == 0)
            continue;

        if (!BN_add(s, dA, BN_value_one())
                || !ec_group_do_inverse_ord(group, s, s, ctx)
                || !BN_mod_mul(tmp, dA, r, order, ctx)
                || !BN_sub(tmp, k, tmp)
                || !BN_mod_mul(s, s, tmp, order, ctx)) {
            SM2err(SM2_F_SM2_SIG_GEN, ERR_R_BN_LIB);
            goto done;
        }

        sig = ECDSA_SIG_new();
        if (sig == NULL) {
            SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
            goto done;
        }

         /* takes ownership of r and s */
        ECDSA_SIG_set0(sig, r, s);
        break;
    }

 done:
    if (sig == NULL) {
        BN_free(r);
        BN_free(s);
    }

    BN_CTX_free(ctx);
    EC_POINT_free(kG);
    return sig;
}

static int sm2_sig_verify(const EC_KEY *key, const ECDSA_SIG *sig,
                          const BIGNUM *e)
{
    int ret = 0;
    const EC_GROUP *group = EC_KEY_get0_group(key);
    const BIGNUM *order = EC_GROUP_get0_order(group);
    BN_CTX *ctx = NULL;
    EC_POINT *pt = NULL;
    BIGNUM *t = NULL;
    BIGNUM *x1 = NULL;
    const BIGNUM *r = NULL;
    const BIGNUM *s = NULL;

    ctx = BN_CTX_new();
    pt = EC_POINT_new(group);
    if (ctx == NULL || pt == NULL) {
        SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_MALLOC_FAILURE);
        goto done;
    }

    BN_CTX_start(ctx);
    t = BN_CTX_get(ctx);
    x1 = BN_CTX_get(ctx);
    if (x1 == NULL) {
        SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_MALLOC_FAILURE);
        goto done;
    }

    /*
     * B1: verify whether r' in [1,n-1], verification failed if not
     * B2: vefify whether s' in [1,n-1], verification failed if not
     * B3: set M'~=ZA || M'
     * B4: calculate e'=Hv(M'~)
     * B5: calculate t = (r' + s') modn, verification failed if t=0
     * B6: calculate the point (x1', y1')=[s']G + [t]PA
     * B7: calculate R=(e'+x1') modn, verfication pass if yes, otherwise failed
     */

    ECDSA_SIG_get0(sig, &r, &s);

    if (BN_cmp(r, BN_value_one()) < 0
            || BN_cmp(s, BN_value_one()) < 0
            || BN_cmp(order, r) <= 0
            || BN_cmp(order, s) <= 0) {
        SM2err(SM2_F_SM2_SIG_VERIFY, SM2_R_BAD_SIGNATURE);
        goto done;
    }

    if (!BN_mod_add(t, r, s, order, ctx)) {
        SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_BN_LIB);
        goto done;
    }

    if (BN_is_zero(t)) {
        SM2err(SM2_F_SM2_SIG_VERIFY, SM2_R_BAD_SIGNATURE);
        goto done;
    }

    if (!EC_POINT_mul(group, pt, s, EC_KEY_get0_public_key(key), t, ctx)
            || !EC_POINT_get_affine_coordinates(group, pt, x1, NULL, ctx)) {
        SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_EC_LIB);
        goto done;
    }

    if (!BN_mod_add(t, e, x1, order, ctx)) {
        SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_BN_LIB);
        goto done;
    }

    if (BN_cmp(r, t) == 0)
        ret = 1;

 done:
    EC_POINT_free(pt);
    BN_CTX_free(ctx);
    return ret;
}

ECDSA_SIG *sm2_do_sign(const EC_KEY *key,
                       const EVP_MD *digest,
                       const uint8_t *id,
                       const size_t id_len,
                       const uint8_t *msg, size_t msg_len)
{
    BIGNUM *e = NULL;
    ECDSA_SIG *sig = NULL;

    e = sm2_compute_msg_hash(digest, key, id, id_len, msg, msg_len);
    if (e == NULL) {
        /* SM2err already called */
        goto done;
    }

    sig = sm2_sig_gen(key, e);

 done:
    BN_free(e);
    return sig;
}

int sm2_do_verify(const EC_KEY *key,
                  const EVP_MD *digest,
                  const ECDSA_SIG *sig,
                  const uint8_t *id,
                  const size_t id_len,
                  const uint8_t *msg, size_t msg_len)
{
    BIGNUM *e = NULL;
    int ret = 0;

    e = sm2_compute_msg_hash(digest, key, id, id_len, msg, msg_len);
    if (e == NULL) {
        /* SM2err already called */
        goto done;
    }

    ret = sm2_sig_verify(key, sig, e);

 done:
    BN_free(e);
    return ret;
}

int sm2_sign(const unsigned char *dgst, int dgstlen,
             unsigned char *sig, unsigned int *siglen, EC_KEY *eckey)
{
    BIGNUM *e = NULL;
    ECDSA_SIG *s = NULL;
    int sigleni;
    int ret = -1;

    e = BN_bin2bn(dgst, dgstlen, NULL);
    if (e == NULL) {
       SM2err(SM2_F_SM2_SIGN, ERR_R_BN_LIB);
       goto done;
    }

    s = sm2_sig_gen(eckey, e);

    sigleni = i2d_ECDSA_SIG(s, &sig);
    if (sigleni < 0) {
       SM2err(SM2_F_SM2_SIGN, ERR_R_INTERNAL_ERROR);
       goto done;
    }
    *siglen = (unsigned int)sigleni;

    ret = 1;

 done:
    ECDSA_SIG_free(s);
    BN_free(e);
    return ret;
}

int sm2_verify(const unsigned char *dgst, int dgstlen,
               const unsigned char *sig, int sig_len, EC_KEY *eckey)
{
    ECDSA_SIG *s = NULL;
    BIGNUM *e = NULL;
    const unsigned char *p = sig;
    unsigned char *der = NULL;
    int derlen = -1;
    int ret = -1;

    s = ECDSA_SIG_new();
    if (s == NULL) {
        SM2err(SM2_F_SM2_VERIFY, ERR_R_MALLOC_FAILURE);
        goto done;
    }
    if (d2i_ECDSA_SIG(&s, &p, sig_len) == NULL) {
        SM2err(SM2_F_SM2_VERIFY, SM2_R_INVALID_ENCODING);
        goto done;
    }
    /* Ensure signature uses DER and doesn't have trailing garbage */
    derlen = i2d_ECDSA_SIG(s, &der);
    if (derlen != sig_len || memcmp(sig, der, derlen) != 0) {
        SM2err(SM2_F_SM2_VERIFY, SM2_R_INVALID_ENCODING);
        goto done;
    }

    e = BN_bin2bn(dgst, dgstlen, NULL);
    if (e == NULL) {
        SM2err(SM2_F_SM2_VERIFY, ERR_R_BN_LIB);
        goto done;
    }

    ret = sm2_sig_verify(eckey, s, e);

 done:
    OPENSSL_free(der);
    BN_free(e);
    ECDSA_SIG_free(s);
    return ret;
}
Commit	Line	Data
3d328a44	1	/*
b0edda11	2	* Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.
3d328a44 JL	3	* Copyright 2017 Ribose Inc. All Rights Reserved.
	4	* Ported from Ribose contributions from Botan.
	5	*
	6	* Licensed under the OpenSSL license (the "License"). You may not use
	7	* this file except in compliance with the License. You can obtain a copy
	8	* in the file LICENSE in the source distribution or at
	9	* https://www.openssl.org/source/license.html
	10	*/
	11
e425f90f	12	#include "internal/sm2.h"
2398404e	13	#include "internal/sm2err.h"
469c2c4a	14	#include "internal/ec_int.h" /* ec_group_do_inverse_ord() */
2398404e	15	#include <openssl/err.h>
3d328a44	16	#include <openssl/evp.h>
2398404e	17	#include <openssl/err.h>
3d328a44 JL	18	#include <openssl/bn.h>
	19	#include <string.h>
	20
00433bad PY	21	int sm2_compute_userid_digest(uint8_t *out,
	22	const EVP_MD *digest,
	23	const uint8_t *id,
	24	const size_t id_len,
	25	const EC_KEY *key)
5bd0abe7 PY	26	{
	27	int rc = 0;
	28	const EC_GROUP *group = EC_KEY_get0_group(key);
	29	BN_CTX *ctx = NULL;
	30	EVP_MD_CTX *hash = NULL;
	31	BIGNUM *p = NULL;
	32	BIGNUM *a = NULL;
	33	BIGNUM *b = NULL;
	34	BIGNUM *xG = NULL;
	35	BIGNUM *yG = NULL;
	36	BIGNUM *xA = NULL;
	37	BIGNUM *yA = NULL;
	38	int p_bytes = 0;
	39	uint8_t *buf = NULL;
5bd0abe7 PY	40	uint16_t entla = 0;
	41	uint8_t e_byte = 0;
	42
	43	hash = EVP_MD_CTX_new();
	44	ctx = BN_CTX_new();
	45	if (hash == NULL \|\| ctx == NULL) {
	46	SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_MALLOC_FAILURE);
	47	goto done;
	48	}
	49
	50	p = BN_CTX_get(ctx);
	51	a = BN_CTX_get(ctx);
	52	b = BN_CTX_get(ctx);
	53	xG = BN_CTX_get(ctx);
	54	yG = BN_CTX_get(ctx);
	55	xA = BN_CTX_get(ctx);
	56	yA = BN_CTX_get(ctx);
	57
	58	if (yA == NULL) {
	59	SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_MALLOC_FAILURE);
	60	goto done;
	61	}
	62
	63	if (!EVP_DigestInit(hash, digest)) {
	64	SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_EVP_LIB);
	65	goto done;
	66	}
	67
	68	/* Z = SM3(ENTLA \|\| IDA \|\| a \|\| b \|\| xG \|\| yG \|\| xA \|\| yA) */
	69
00433bad	70	if (id_len >= (UINT16_MAX / 8)) {
5bd0abe7 PY	71	/* too large */
	72	SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, SM2_R_USER_ID_TOO_LARGE);
	73	goto done;
	74	}
	75
00433bad	76	entla = (uint16_t)(8 * id_len);
5bd0abe7 PY	77
	78	e_byte = entla >> 8;
	79	if (!EVP_DigestUpdate(hash, &e_byte, 1)) {
	80	SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_EVP_LIB);
	81	goto done;
	82	}
	83	e_byte = entla & 0xFF;
	84	if (!EVP_DigestUpdate(hash, &e_byte, 1)
00433bad	85	\|\| !EVP_DigestUpdate(hash, id, id_len)) {
5bd0abe7 PY	86	SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_EVP_LIB);
	87	goto done;
	88	}
	89
	90	if (!EC_GROUP_get_curve(group, p, a, b, ctx)) {
	91	SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_EC_LIB);
	92	goto done;
	93	}
	94
	95	p_bytes = BN_num_bytes(p);
	96	buf = OPENSSL_zalloc(p_bytes);
	97	if (buf == NULL) {
	98	SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_MALLOC_FAILURE);
	99	goto done;
	100	}
	101
	102	if (BN_bn2binpad(a, buf, p_bytes) < 0
	103	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
	104	\|\| BN_bn2binpad(b, buf, p_bytes) < 0
	105	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
	106	\|\| !EC_POINT_get_affine_coordinates(group,
	107	EC_GROUP_get0_generator(group),
	108	xG, yG, ctx)
	109	\|\| BN_bn2binpad(xG, buf, p_bytes) < 0
	110	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
	111	\|\| BN_bn2binpad(yG, buf, p_bytes) < 0
	112	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
	113	\|\| !EC_POINT_get_affine_coordinates(group,
	114	EC_KEY_get0_public_key(key),
	115	xA, yA, ctx)
	116	\|\| BN_bn2binpad(xA, buf, p_bytes) < 0
	117	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
	118	\|\| BN_bn2binpad(yA, buf, p_bytes) < 0
	119	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
	120	\|\| !EVP_DigestFinal(hash, out, NULL)) {
	121	SM2err(SM2_F_SM2_COMPUTE_USERID_DIGEST, ERR_R_INTERNAL_ERROR);
	122	goto done;
	123	}
	124
	125	rc = 1;
	126
	127	done:
	128	OPENSSL_free(buf);
	129	BN_CTX_free(ctx);
	130	EVP_MD_CTX_free(hash);
	131	return rc;
	132	}
	133
2167239a	134	static BIGNUM sm2_compute_msg_hash(const EVP_MD digest,
2398404e	135	const EC_KEY *key,
00433bad PY	136	const uint8_t *id,
00433bad PY	137	const size_t id_len,
2398404e	138	const uint8_t *msg, size_t msg_len)
3d328a44 JL	139	{
	140	EVP_MD_CTX *hash = EVP_MD_CTX_new();
	141	const int md_size = EVP_MD_size(digest);
3e0076c2	142	uint8_t *za = NULL;
3d328a44 JL	143	BIGNUM *e = NULL;
3d328a44 JL	144
3e0076c2 MC	145	if (md_size < 0) {
3e0076c2 MC	146	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, SM2_R_INVALID_DIGEST);
3d328a44	147	goto done;
245be530	148	}
3d328a44	149
3e0076c2 MC	150	za = OPENSSL_zalloc(md_size);
	151	if (hash == NULL \|\| za == NULL) {
	152	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_MALLOC_FAILURE);
3d328a44	153	goto done;
245be530	154	}
3d328a44	155
00433bad	156	if (!sm2_compute_userid_digest(za, digest, id, id_len, key)) {
245be530	157	/* SM2err already called */
3d328a44	158	goto done;
245be530	159	}
3d328a44	160
245be530 MC	161	if (!EVP_DigestInit(hash, digest)
	162	\|\| !EVP_DigestUpdate(hash, za, md_size)
	163	\|\| !EVP_DigestUpdate(hash, msg, msg_len)
	164	/* reuse za buffer to hold H(ZA \|\| M) */
	165	\|\| !EVP_DigestFinal(hash, za, NULL)) {
2398404e	166	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_EVP_LIB);
3d328a44	167	goto done;
245be530	168	}
3d328a44 JL	169
3d328a44 JL	170	e = BN_bin2bn(za, md_size, NULL);
245be530 MC	171	if (e == NULL)
245be530 MC	172	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_INTERNAL_ERROR);
3d328a44 JL	173
	174	done:
	175	OPENSSL_free(za);
	176	EVP_MD_CTX_free(hash);
	177	return e;
	178	}
	179
2167239a	180	static ECDSA_SIG sm2_sig_gen(const EC_KEY key, const BIGNUM *e)
3d328a44 JL	181	{
	182	const BIGNUM *dA = EC_KEY_get0_private_key(key);
	183	const EC_GROUP *group = EC_KEY_get0_group(key);
	184	const BIGNUM *order = EC_GROUP_get0_order(group);
3d328a44 JL	185	ECDSA_SIG *sig = NULL;
	186	EC_POINT *kG = NULL;
	187	BN_CTX *ctx = NULL;
	188	BIGNUM *k = NULL;
	189	BIGNUM *rk = NULL;
	190	BIGNUM *r = NULL;
	191	BIGNUM *s = NULL;
	192	BIGNUM *x1 = NULL;
	193	BIGNUM *tmp = NULL;
	194
	195	kG = EC_POINT_new(group);
3d328a44	196	ctx = BN_CTX_new();
245be530	197	if (kG == NULL \|\| ctx == NULL) {
2398404e	198	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
3d328a44	199	goto done;
245be530	200	}
3d328a44	201
245be530	202	BN_CTX_start(ctx);
3d328a44 JL	203	k = BN_CTX_get(ctx);
	204	rk = BN_CTX_get(ctx);
	205	x1 = BN_CTX_get(ctx);
	206	tmp = BN_CTX_get(ctx);
245be530 MC	207	if (tmp == NULL) {
245be530 MC	208	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
3d328a44	209	goto done;
245be530	210	}
3d328a44	211
245be530 MC	212	/*
	213	* These values are returned and so should not be allocated out of the
	214	* context
	215	*/
3d328a44 JL	216	r = BN_new();
	217	s = BN_new();
	218
245be530	219	if (r == NULL \|\| s == NULL) {
2398404e	220	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
3d328a44	221	goto done;
245be530	222	}
3d328a44 JL	223
3d328a44 JL	224	for (;;) {
245be530 MC	225	if (!BN_priv_rand_range(k, order)) {
245be530 MC	226	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_INTERNAL_ERROR);
9e4c9777	227	goto done;
245be530	228	}
3d328a44	229
245be530	230	if (!EC_POINT_mul(group, kG, k, NULL, NULL, ctx)
9cc570d4	231	\|\| !EC_POINT_get_affine_coordinates(group, kG, x1, NULL,
5bd0abe7	232	ctx)
245be530 MC	233	\|\| !BN_mod_add(r, e, x1, order, ctx)) {
245be530 MC	234	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_INTERNAL_ERROR);
3d328a44	235	goto done;
245be530	236	}
3d328a44 JL	237
	238	/* try again if r == 0 or r+k == n */
	239	if (BN_is_zero(r))
	240	continue;
	241
245be530 MC	242	if (!BN_add(rk, r, k)) {
	243	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_INTERNAL_ERROR);
	244	goto done;
	245	}
3d328a44 JL	246
	247	if (BN_cmp(rk, order) == 0)
	248	continue;
	249
245be530	250	if (!BN_add(s, dA, BN_value_one())
469c2c4a	251	\|\| !ec_group_do_inverse_ord(group, s, s, ctx)
245be530 MC	252	\|\| !BN_mod_mul(tmp, dA, r, order, ctx)
	253	\|\| !BN_sub(tmp, k, tmp)
	254	\|\| !BN_mod_mul(s, s, tmp, order, ctx)) {
	255	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_BN_LIB);
	256	goto done;
	257	}
3d328a44 JL	258
3d328a44 JL	259	sig = ECDSA_SIG_new();
245be530	260	if (sig == NULL) {
2398404e	261	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
3d328a44	262	goto done;
245be530	263	}
3d328a44 JL	264
	265	/* takes ownership of r and s */
	266	ECDSA_SIG_set0(sig, r, s);
	267	break;
	268	}
	269
	270	done:
3d328a44 JL	271	if (sig == NULL) {
	272	BN_free(r);
	273	BN_free(s);
	274	}
	275
	276	BN_CTX_free(ctx);
	277	EC_POINT_free(kG);
	278	return sig;
3d328a44 JL	279	}
3d328a44 JL	280
2167239a	281	static int sm2_sig_verify(const EC_KEY key, const ECDSA_SIG sig,
245be530	282	const BIGNUM *e)
3d328a44 JL	283	{
	284	int ret = 0;
	285	const EC_GROUP *group = EC_KEY_get0_group(key);
	286	const BIGNUM *order = EC_GROUP_get0_order(group);
	287	BN_CTX *ctx = NULL;
	288	EC_POINT *pt = NULL;
3d328a44 JL	289	BIGNUM *t = NULL;
	290	BIGNUM *x1 = NULL;
	291	const BIGNUM *r = NULL;
	292	const BIGNUM *s = NULL;
	293
	294	ctx = BN_CTX_new();
3d328a44	295	pt = EC_POINT_new(group);
245be530	296	if (ctx == NULL \|\| pt == NULL) {
2398404e	297	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_MALLOC_FAILURE);
3d328a44	298	goto done;
245be530	299	}
3d328a44 JL	300
3d328a44 JL	301	BN_CTX_start(ctx);
3d328a44 JL	302	t = BN_CTX_get(ctx);
3d328a44 JL	303	x1 = BN_CTX_get(ctx);
245be530 MC	304	if (x1 == NULL) {
	305	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_MALLOC_FAILURE);
	306	goto done;
	307	}
3d328a44 JL	308
3d328a44 JL	309	/*
245be530 MC	310	* B1: verify whether r' in [1,n-1], verification failed if not
	311	* B2: vefify whether s' in [1,n-1], verification failed if not
	312	* B3: set M'~=ZA \|\| M'
	313	* B4: calculate e'=Hv(M'~)
	314	* B5: calculate t = (r' + s') modn, verification failed if t=0
	315	* B6: calculate the point (x1', y1')=[s']G + [t]PA
	316	* B7: calculate R=(e'+x1') modn, verfication pass if yes, otherwise failed
3d328a44 JL	317	*/
	318
	319	ECDSA_SIG_get0(sig, &r, &s);
	320
245be530 MC	321	if (BN_cmp(r, BN_value_one()) < 0
	322	\|\| BN_cmp(s, BN_value_one()) < 0
	323	\|\| BN_cmp(order, r) <= 0
	324	\|\| BN_cmp(order, s) <= 0) {
2398404e	325	SM2err(SM2_F_SM2_SIG_VERIFY, SM2_R_BAD_SIGNATURE);
3d328a44	326	goto done;
245be530	327	}
3d328a44	328
245be530	329	if (!BN_mod_add(t, r, s, order, ctx)) {
2398404e	330	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_BN_LIB);
3d328a44	331	goto done;
245be530	332	}
3d328a44	333
245be530	334	if (BN_is_zero(t)) {
2398404e	335	SM2err(SM2_F_SM2_SIG_VERIFY, SM2_R_BAD_SIGNATURE);
3d328a44	336	goto done;
245be530	337	}
3d328a44	338
245be530	339	if (!EC_POINT_mul(group, pt, s, EC_KEY_get0_public_key(key), t, ctx)
9cc570d4	340	\|\| !EC_POINT_get_affine_coordinates(group, pt, x1, NULL, ctx)) {
2398404e	341	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_EC_LIB);
3d328a44	342	goto done;
245be530	343	}
3d328a44	344
245be530	345	if (!BN_mod_add(t, e, x1, order, ctx)) {
2398404e	346	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_BN_LIB);
3d328a44	347	goto done;
245be530	348	}
3d328a44 JL	349
	350	if (BN_cmp(r, t) == 0)
	351	ret = 1;
	352
	353	done:
	354	EC_POINT_free(pt);
	355	BN_CTX_free(ctx);
	356	return ret;
	357	}
	358
2167239a	359	ECDSA_SIG sm2_do_sign(const EC_KEY key,
3d328a44	360	const EVP_MD *digest,
00433bad PY	361	const uint8_t *id,
	362	const size_t id_len,
	363	const uint8_t *msg, size_t msg_len)
3d328a44 JL	364	{
	365	BIGNUM *e = NULL;
	366	ECDSA_SIG *sig = NULL;
	367
00433bad	368	e = sm2_compute_msg_hash(digest, key, id, id_len, msg, msg_len);
245be530 MC	369	if (e == NULL) {
245be530 MC	370	/* SM2err already called */
3d328a44	371	goto done;
245be530	372	}
3d328a44	373
2167239a	374	sig = sm2_sig_gen(key, e);
3d328a44 JL	375
	376	done:
	377	BN_free(e);
	378	return sig;
	379	}
	380
2167239a	381	int sm2_do_verify(const EC_KEY *key,
3d328a44 JL	382	const EVP_MD *digest,
3d328a44 JL	383	const ECDSA_SIG *sig,
00433bad PY	384	const uint8_t *id,
	385	const size_t id_len,
	386	const uint8_t *msg, size_t msg_len)
3d328a44 JL	387	{
3d328a44 JL	388	BIGNUM *e = NULL;
245be530	389	int ret = 0;
3d328a44	390
00433bad	391	e = sm2_compute_msg_hash(digest, key, id, id_len, msg, msg_len);
245be530 MC	392	if (e == NULL) {
245be530 MC	393	/* SM2err already called */
3d328a44	394	goto done;
245be530	395	}
3d328a44	396
2167239a	397	ret = sm2_sig_verify(key, sig, e);
3d328a44 JL	398
	399	done:
	400	BN_free(e);
	401	return ret;
	402	}
	403
ddb634fe	404	int sm2_sign(const unsigned char *dgst, int dgstlen,
3d328a44 JL	405	unsigned char sig, unsigned int siglen, EC_KEY *eckey)
	406	{
	407	BIGNUM *e = NULL;
	408	ECDSA_SIG *s = NULL;
245be530	409	int sigleni;
3d328a44 JL	410	int ret = -1;
3d328a44 JL	411
3d328a44	412	e = BN_bin2bn(dgst, dgstlen, NULL);
245be530 MC	413	if (e == NULL) {
	414	SM2err(SM2_F_SM2_SIGN, ERR_R_BN_LIB);
	415	goto done;
	416	}
3d328a44	417
2167239a	418	s = sm2_sig_gen(eckey, e);
3d328a44	419
245be530 MC	420	sigleni = i2d_ECDSA_SIG(s, &sig);
	421	if (sigleni < 0) {
	422	SM2err(SM2_F_SM2_SIGN, ERR_R_INTERNAL_ERROR);
	423	goto done;
	424	}
	425	*siglen = (unsigned int)sigleni;
3d328a44	426
67cc2bae	427	ret = 1;
3d328a44 JL	428
	429	done:
	430	ECDSA_SIG_free(s);
	431	BN_free(e);
	432	return ret;
	433	}
	434
ddb634fe	435	int sm2_verify(const unsigned char *dgst, int dgstlen,
3d328a44 JL	436	const unsigned char sig, int sig_len, EC_KEY eckey)
	437	{
	438	ECDSA_SIG *s = NULL;
	439	BIGNUM *e = NULL;
	440	const unsigned char *p = sig;
	441	unsigned char *der = NULL;
	442	int derlen = -1;
	443	int ret = -1;
	444
3d328a44	445	s = ECDSA_SIG_new();
245be530	446	if (s == NULL) {
2398404e	447	SM2err(SM2_F_SM2_VERIFY, ERR_R_MALLOC_FAILURE);
3d328a44	448	goto done;
245be530 MC	449	}
245be530 MC	450	if (d2i_ECDSA_SIG(&s, &p, sig_len) == NULL) {
2398404e	451	SM2err(SM2_F_SM2_VERIFY, SM2_R_INVALID_ENCODING);
3d328a44	452	goto done;
245be530	453	}
3d328a44 JL	454	/* Ensure signature uses DER and doesn't have trailing garbage */
3d328a44 JL	455	derlen = i2d_ECDSA_SIG(s, &der);
245be530	456	if (derlen != sig_len \|\| memcmp(sig, der, derlen) != 0) {
2398404e	457	SM2err(SM2_F_SM2_VERIFY, SM2_R_INVALID_ENCODING);
3d328a44	458	goto done;
245be530	459	}
3d328a44 JL	460
3d328a44 JL	461	e = BN_bin2bn(dgst, dgstlen, NULL);
245be530 MC	462	if (e == NULL) {
	463	SM2err(SM2_F_SM2_VERIFY, ERR_R_BN_LIB);
	464	goto done;
	465	}
3d328a44	466
2167239a	467	ret = sm2_sig_verify(eckey, s, e);
3d328a44 JL	468
	469	done:
	470	OPENSSL_free(der);
	471	BN_free(e);
	472	ECDSA_SIG_free(s);
	473	return ret;
	474	}