[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 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
 */

#include "internal/sm2.h"
#include "internal/sm2err.h"
#include "internal/ec_int.h" /* ec_group_do_inverse_ord() */
#include "internal/numbers.h"
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/bn.h>
#include <string.h>

int sm2_compute_z_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 entl = 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_Z_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_Z_DIGEST, ERR_R_MALLOC_FAILURE);
        goto done;
    }

    if (!EVP_DigestInit(hash, digest)) {
        SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_EVP_LIB);
        goto done;
    }

    /* Z = h(ENTL || ID || a || b || xG || yG || xA || yA) */

    if (id_len >= (UINT16_MAX / 8)) {
        /* too large */
        SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, SM2_R_ID_TOO_LARGE);
        goto done;
    }

    entl = (uint16_t)(8 * id_len);

    e_byte = entl >> 8;
    if (!EVP_DigestUpdate(hash, &e_byte, 1)) {
        SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_EVP_LIB);
        goto done;
    }
    e_byte = entl & 0xFF;
    if (!EVP_DigestUpdate(hash, &e_byte, 1)) {
        SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_EVP_LIB);
        goto done;
    }

    if (id_len > 0 && !EVP_DigestUpdate(hash, id, id_len)) {
        SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_EVP_LIB);
        goto done;
    }

    if (!EC_GROUP_get_curve(group, p, a, b, ctx)) {
        SM2err(SM2_F_SM2_COMPUTE_Z_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_Z_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_Z_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 *z = NULL;
    BIGNUM *e = NULL;

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

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

    if (!sm2_compute_z_digest(z, digest, id, id_len, key)) {
        /* SM2err already called */
        goto done;
    }

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

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

 done:
    OPENSSL_free(z);
    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	*
f9f859ad	6	* Licensed under the Apache License 2.0 (the "License"). You may not use
3d328a44 JL	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() */
88ea3685	15	#include "internal/numbers.h"
2398404e	16	#include <openssl/err.h>
3d328a44	17	#include <openssl/evp.h>
2398404e	18	#include <openssl/err.h>
3d328a44 JL	19	#include <openssl/bn.h>
	20	#include <string.h>
	21
4803717f PY	22	int sm2_compute_z_digest(uint8_t *out,
	23	const EVP_MD *digest,
	24	const uint8_t *id,
	25	const size_t id_len,
	26	const EC_KEY *key)
5bd0abe7 PY	27	{
	28	int rc = 0;
	29	const EC_GROUP *group = EC_KEY_get0_group(key);
	30	BN_CTX *ctx = NULL;
	31	EVP_MD_CTX *hash = NULL;
	32	BIGNUM *p = NULL;
	33	BIGNUM *a = NULL;
	34	BIGNUM *b = NULL;
	35	BIGNUM *xG = NULL;
	36	BIGNUM *yG = NULL;
	37	BIGNUM *xA = NULL;
	38	BIGNUM *yA = NULL;
	39	int p_bytes = 0;
	40	uint8_t *buf = NULL;
4803717f	41	uint16_t entl = 0;
5bd0abe7 PY	42	uint8_t e_byte = 0;
	43
	44	hash = EVP_MD_CTX_new();
	45	ctx = BN_CTX_new();
	46	if (hash == NULL \|\| ctx == NULL) {
4803717f	47	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_MALLOC_FAILURE);
5bd0abe7 PY	48	goto done;
	49	}
	50
	51	p = BN_CTX_get(ctx);
	52	a = BN_CTX_get(ctx);
	53	b = BN_CTX_get(ctx);
	54	xG = BN_CTX_get(ctx);
	55	yG = BN_CTX_get(ctx);
	56	xA = BN_CTX_get(ctx);
	57	yA = BN_CTX_get(ctx);
	58
	59	if (yA == NULL) {
4803717f	60	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_MALLOC_FAILURE);
5bd0abe7 PY	61	goto done;
	62	}
	63
	64	if (!EVP_DigestInit(hash, digest)) {
4803717f	65	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_EVP_LIB);
5bd0abe7 PY	66	goto done;
	67	}
	68
4803717f	69	/* Z = h(ENTL \|\| ID \|\| a \|\| b \|\| xG \|\| yG \|\| xA \|\| yA) */
5bd0abe7	70
00433bad	71	if (id_len >= (UINT16_MAX / 8)) {
5bd0abe7	72	/* too large */
4803717f	73	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, SM2_R_ID_TOO_LARGE);
5bd0abe7 PY	74	goto done;
	75	}
	76
4803717f	77	entl = (uint16_t)(8 * id_len);
5bd0abe7	78
4803717f	79	e_byte = entl >> 8;
5bd0abe7	80	if (!EVP_DigestUpdate(hash, &e_byte, 1)) {
4803717f	81	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_EVP_LIB);
5bd0abe7 PY	82	goto done;
5bd0abe7 PY	83	}
4803717f PY	84	e_byte = entl & 0xFF;
	85	if (!EVP_DigestUpdate(hash, &e_byte, 1)) {
	86	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_EVP_LIB);
	87	goto done;
	88	}
	89
	90	if (id_len > 0 && !EVP_DigestUpdate(hash, id, id_len)) {
	91	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_EVP_LIB);
5bd0abe7 PY	92	goto done;
	93	}
	94
	95	if (!EC_GROUP_get_curve(group, p, a, b, ctx)) {
4803717f	96	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_EC_LIB);
5bd0abe7 PY	97	goto done;
	98	}
	99
	100	p_bytes = BN_num_bytes(p);
	101	buf = OPENSSL_zalloc(p_bytes);
	102	if (buf == NULL) {
4803717f	103	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_MALLOC_FAILURE);
5bd0abe7 PY	104	goto done;
	105	}
	106
	107	if (BN_bn2binpad(a, buf, p_bytes) < 0
	108	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
	109	\|\| BN_bn2binpad(b, buf, p_bytes) < 0
	110	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
	111	\|\| !EC_POINT_get_affine_coordinates(group,
	112	EC_GROUP_get0_generator(group),
	113	xG, yG, ctx)
	114	\|\| BN_bn2binpad(xG, buf, p_bytes) < 0
	115	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
	116	\|\| BN_bn2binpad(yG, buf, p_bytes) < 0
	117	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
	118	\|\| !EC_POINT_get_affine_coordinates(group,
	119	EC_KEY_get0_public_key(key),
	120	xA, yA, ctx)
	121	\|\| BN_bn2binpad(xA, buf, p_bytes) < 0
	122	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
	123	\|\| BN_bn2binpad(yA, buf, p_bytes) < 0
	124	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
	125	\|\| !EVP_DigestFinal(hash, out, NULL)) {
4803717f	126	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_INTERNAL_ERROR);
5bd0abe7 PY	127	goto done;
	128	}
	129
	130	rc = 1;
	131
	132	done:
	133	OPENSSL_free(buf);
	134	BN_CTX_free(ctx);
	135	EVP_MD_CTX_free(hash);
	136	return rc;
	137	}
	138
2167239a	139	static BIGNUM sm2_compute_msg_hash(const EVP_MD digest,
2398404e	140	const EC_KEY *key,
00433bad PY	141	const uint8_t *id,
00433bad PY	142	const size_t id_len,
2398404e	143	const uint8_t *msg, size_t msg_len)
3d328a44 JL	144	{
	145	EVP_MD_CTX *hash = EVP_MD_CTX_new();
	146	const int md_size = EVP_MD_size(digest);
4803717f	147	uint8_t *z = NULL;
3d328a44 JL	148	BIGNUM *e = NULL;
3d328a44 JL	149
3e0076c2 MC	150	if (md_size < 0) {
3e0076c2 MC	151	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, SM2_R_INVALID_DIGEST);
3d328a44	152	goto done;
245be530	153	}
3d328a44	154
4803717f PY	155	z = OPENSSL_zalloc(md_size);
4803717f PY	156	if (hash == NULL \|\| z == NULL) {
3e0076c2	157	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_MALLOC_FAILURE);
3d328a44	158	goto done;
245be530	159	}
3d328a44	160
4803717f	161	if (!sm2_compute_z_digest(z, digest, id, id_len, key)) {
245be530	162	/* SM2err already called */
3d328a44	163	goto done;
245be530	164	}
3d328a44	165
245be530	166	if (!EVP_DigestInit(hash, digest)
4803717f	167	\|\| !EVP_DigestUpdate(hash, z, md_size)
245be530	168	\|\| !EVP_DigestUpdate(hash, msg, msg_len)
4803717f PY	169	/* reuse z buffer to hold H(Z \|\| M) */
4803717f PY	170	\|\| !EVP_DigestFinal(hash, z, NULL)) {
2398404e	171	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_EVP_LIB);
3d328a44	172	goto done;
245be530	173	}
3d328a44	174
4803717f	175	e = BN_bin2bn(z, md_size, NULL);
245be530 MC	176	if (e == NULL)
245be530 MC	177	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_INTERNAL_ERROR);
3d328a44 JL	178
3d328a44 JL	179	done:
4803717f	180	OPENSSL_free(z);
3d328a44 JL	181	EVP_MD_CTX_free(hash);
	182	return e;
	183	}
	184
2167239a	185	static ECDSA_SIG sm2_sig_gen(const EC_KEY key, const BIGNUM *e)
3d328a44 JL	186	{
	187	const BIGNUM *dA = EC_KEY_get0_private_key(key);
	188	const EC_GROUP *group = EC_KEY_get0_group(key);
	189	const BIGNUM *order = EC_GROUP_get0_order(group);
3d328a44 JL	190	ECDSA_SIG *sig = NULL;
	191	EC_POINT *kG = NULL;
	192	BN_CTX *ctx = NULL;
	193	BIGNUM *k = NULL;
	194	BIGNUM *rk = NULL;
	195	BIGNUM *r = NULL;
	196	BIGNUM *s = NULL;
	197	BIGNUM *x1 = NULL;
	198	BIGNUM *tmp = NULL;
	199
	200	kG = EC_POINT_new(group);
3d328a44	201	ctx = BN_CTX_new();
245be530	202	if (kG == NULL \|\| ctx == NULL) {
2398404e	203	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
3d328a44	204	goto done;
245be530	205	}
3d328a44	206
245be530	207	BN_CTX_start(ctx);
3d328a44 JL	208	k = BN_CTX_get(ctx);
	209	rk = BN_CTX_get(ctx);
	210	x1 = BN_CTX_get(ctx);
	211	tmp = BN_CTX_get(ctx);
245be530 MC	212	if (tmp == NULL) {
245be530 MC	213	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
3d328a44	214	goto done;
245be530	215	}
3d328a44	216
245be530 MC	217	/*
	218	* These values are returned and so should not be allocated out of the
	219	* context
	220	*/
3d328a44 JL	221	r = BN_new();
	222	s = BN_new();
	223
245be530	224	if (r == NULL \|\| s == NULL) {
2398404e	225	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
3d328a44	226	goto done;
245be530	227	}
3d328a44 JL	228
3d328a44 JL	229	for (;;) {
245be530 MC	230	if (!BN_priv_rand_range(k, order)) {
245be530 MC	231	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_INTERNAL_ERROR);
9e4c9777	232	goto done;
245be530	233	}
3d328a44	234
245be530	235	if (!EC_POINT_mul(group, kG, k, NULL, NULL, ctx)
9cc570d4	236	\|\| !EC_POINT_get_affine_coordinates(group, kG, x1, NULL,
5bd0abe7	237	ctx)
245be530 MC	238	\|\| !BN_mod_add(r, e, x1, order, ctx)) {
245be530 MC	239	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_INTERNAL_ERROR);
3d328a44	240	goto done;
245be530	241	}
3d328a44 JL	242
	243	/* try again if r == 0 or r+k == n */
	244	if (BN_is_zero(r))
	245	continue;
	246
245be530 MC	247	if (!BN_add(rk, r, k)) {
	248	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_INTERNAL_ERROR);
	249	goto done;
	250	}
3d328a44 JL	251
	252	if (BN_cmp(rk, order) == 0)
	253	continue;
	254
245be530	255	if (!BN_add(s, dA, BN_value_one())
469c2c4a	256	\|\| !ec_group_do_inverse_ord(group, s, s, ctx)
245be530 MC	257	\|\| !BN_mod_mul(tmp, dA, r, order, ctx)
	258	\|\| !BN_sub(tmp, k, tmp)
	259	\|\| !BN_mod_mul(s, s, tmp, order, ctx)) {
	260	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_BN_LIB);
	261	goto done;
	262	}
3d328a44 JL	263
3d328a44 JL	264	sig = ECDSA_SIG_new();
245be530	265	if (sig == NULL) {
2398404e	266	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
3d328a44	267	goto done;
245be530	268	}
3d328a44 JL	269
	270	/* takes ownership of r and s */
	271	ECDSA_SIG_set0(sig, r, s);
	272	break;
	273	}
	274
	275	done:
3d328a44 JL	276	if (sig == NULL) {
	277	BN_free(r);
	278	BN_free(s);
	279	}
	280
	281	BN_CTX_free(ctx);
	282	EC_POINT_free(kG);
	283	return sig;
3d328a44 JL	284	}
3d328a44 JL	285
2167239a	286	static int sm2_sig_verify(const EC_KEY key, const ECDSA_SIG sig,
245be530	287	const BIGNUM *e)
3d328a44 JL	288	{
	289	int ret = 0;
	290	const EC_GROUP *group = EC_KEY_get0_group(key);
	291	const BIGNUM *order = EC_GROUP_get0_order(group);
	292	BN_CTX *ctx = NULL;
	293	EC_POINT *pt = NULL;
3d328a44 JL	294	BIGNUM *t = NULL;
	295	BIGNUM *x1 = NULL;
	296	const BIGNUM *r = NULL;
	297	const BIGNUM *s = NULL;
	298
	299	ctx = BN_CTX_new();
3d328a44	300	pt = EC_POINT_new(group);
245be530	301	if (ctx == NULL \|\| pt == NULL) {
2398404e	302	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_MALLOC_FAILURE);
3d328a44	303	goto done;
245be530	304	}
3d328a44 JL	305
3d328a44 JL	306	BN_CTX_start(ctx);
3d328a44 JL	307	t = BN_CTX_get(ctx);
3d328a44 JL	308	x1 = BN_CTX_get(ctx);
245be530 MC	309	if (x1 == NULL) {
	310	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_MALLOC_FAILURE);
	311	goto done;
	312	}
3d328a44 JL	313
3d328a44 JL	314	/*
245be530 MC	315	* B1: verify whether r' in [1,n-1], verification failed if not
	316	* B2: vefify whether s' in [1,n-1], verification failed if not
	317	* B3: set M'~=ZA \|\| M'
	318	* B4: calculate e'=Hv(M'~)
	319	* B5: calculate t = (r' + s') modn, verification failed if t=0
	320	* B6: calculate the point (x1', y1')=[s']G + [t]PA
	321	* B7: calculate R=(e'+x1') modn, verfication pass if yes, otherwise failed
3d328a44 JL	322	*/
	323
	324	ECDSA_SIG_get0(sig, &r, &s);
	325
245be530 MC	326	if (BN_cmp(r, BN_value_one()) < 0
	327	\|\| BN_cmp(s, BN_value_one()) < 0
	328	\|\| BN_cmp(order, r) <= 0
	329	\|\| BN_cmp(order, s) <= 0) {
2398404e	330	SM2err(SM2_F_SM2_SIG_VERIFY, SM2_R_BAD_SIGNATURE);
3d328a44	331	goto done;
245be530	332	}
3d328a44	333
245be530	334	if (!BN_mod_add(t, r, s, order, ctx)) {
2398404e	335	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_BN_LIB);
3d328a44	336	goto done;
245be530	337	}
3d328a44	338
245be530	339	if (BN_is_zero(t)) {
2398404e	340	SM2err(SM2_F_SM2_SIG_VERIFY, SM2_R_BAD_SIGNATURE);
3d328a44	341	goto done;
245be530	342	}
3d328a44	343
245be530	344	if (!EC_POINT_mul(group, pt, s, EC_KEY_get0_public_key(key), t, ctx)
9cc570d4	345	\|\| !EC_POINT_get_affine_coordinates(group, pt, x1, NULL, ctx)) {
2398404e	346	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_EC_LIB);
3d328a44	347	goto done;
245be530	348	}
3d328a44	349
245be530	350	if (!BN_mod_add(t, e, x1, order, ctx)) {
2398404e	351	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_BN_LIB);
3d328a44	352	goto done;
245be530	353	}
3d328a44 JL	354
	355	if (BN_cmp(r, t) == 0)
	356	ret = 1;
	357
	358	done:
	359	EC_POINT_free(pt);
	360	BN_CTX_free(ctx);
	361	return ret;
	362	}
	363
2167239a	364	ECDSA_SIG sm2_do_sign(const EC_KEY key,
3d328a44	365	const EVP_MD *digest,
00433bad PY	366	const uint8_t *id,
	367	const size_t id_len,
	368	const uint8_t *msg, size_t msg_len)
3d328a44 JL	369	{
	370	BIGNUM *e = NULL;
	371	ECDSA_SIG *sig = NULL;
	372
00433bad	373	e = sm2_compute_msg_hash(digest, key, id, id_len, msg, msg_len);
245be530 MC	374	if (e == NULL) {
245be530 MC	375	/* SM2err already called */
3d328a44	376	goto done;
245be530	377	}
3d328a44	378
2167239a	379	sig = sm2_sig_gen(key, e);
3d328a44 JL	380
	381	done:
	382	BN_free(e);
	383	return sig;
	384	}
	385
2167239a	386	int sm2_do_verify(const EC_KEY *key,
3d328a44 JL	387	const EVP_MD *digest,
3d328a44 JL	388	const ECDSA_SIG *sig,
00433bad PY	389	const uint8_t *id,
	390	const size_t id_len,
	391	const uint8_t *msg, size_t msg_len)
3d328a44 JL	392	{
3d328a44 JL	393	BIGNUM *e = NULL;
245be530	394	int ret = 0;
3d328a44	395
00433bad	396	e = sm2_compute_msg_hash(digest, key, id, id_len, msg, msg_len);
245be530 MC	397	if (e == NULL) {
245be530 MC	398	/* SM2err already called */
3d328a44	399	goto done;
245be530	400	}
3d328a44	401
2167239a	402	ret = sm2_sig_verify(key, sig, e);
3d328a44 JL	403
	404	done:
	405	BN_free(e);
	406	return ret;
	407	}
	408
ddb634fe	409	int sm2_sign(const unsigned char *dgst, int dgstlen,
3d328a44 JL	410	unsigned char sig, unsigned int siglen, EC_KEY *eckey)
	411	{
	412	BIGNUM *e = NULL;
	413	ECDSA_SIG *s = NULL;
245be530	414	int sigleni;
3d328a44 JL	415	int ret = -1;
3d328a44 JL	416
3d328a44	417	e = BN_bin2bn(dgst, dgstlen, NULL);
245be530 MC	418	if (e == NULL) {
	419	SM2err(SM2_F_SM2_SIGN, ERR_R_BN_LIB);
	420	goto done;
	421	}
3d328a44	422
2167239a	423	s = sm2_sig_gen(eckey, e);
3d328a44	424
245be530 MC	425	sigleni = i2d_ECDSA_SIG(s, &sig);
	426	if (sigleni < 0) {
	427	SM2err(SM2_F_SM2_SIGN, ERR_R_INTERNAL_ERROR);
	428	goto done;
	429	}
	430	*siglen = (unsigned int)sigleni;
3d328a44	431
67cc2bae	432	ret = 1;
3d328a44 JL	433
	434	done:
	435	ECDSA_SIG_free(s);
	436	BN_free(e);
	437	return ret;
	438	}
	439
ddb634fe	440	int sm2_verify(const unsigned char *dgst, int dgstlen,
3d328a44 JL	441	const unsigned char sig, int sig_len, EC_KEY eckey)
	442	{
	443	ECDSA_SIG *s = NULL;
	444	BIGNUM *e = NULL;
	445	const unsigned char *p = sig;
	446	unsigned char *der = NULL;
	447	int derlen = -1;
	448	int ret = -1;
	449
3d328a44	450	s = ECDSA_SIG_new();
245be530	451	if (s == NULL) {
2398404e	452	SM2err(SM2_F_SM2_VERIFY, ERR_R_MALLOC_FAILURE);
3d328a44	453	goto done;
245be530 MC	454	}
245be530 MC	455	if (d2i_ECDSA_SIG(&s, &p, sig_len) == NULL) {
2398404e	456	SM2err(SM2_F_SM2_VERIFY, SM2_R_INVALID_ENCODING);
3d328a44	457	goto done;
245be530	458	}
3d328a44 JL	459	/* Ensure signature uses DER and doesn't have trailing garbage */
3d328a44 JL	460	derlen = i2d_ECDSA_SIG(s, &der);
245be530	461	if (derlen != sig_len \|\| memcmp(sig, der, derlen) != 0) {
2398404e	462	SM2err(SM2_F_SM2_VERIFY, SM2_R_INVALID_ENCODING);
3d328a44	463	goto done;
245be530	464	}
3d328a44 JL	465
3d328a44 JL	466	e = BN_bin2bn(dgst, dgstlen, NULL);
245be530 MC	467	if (e == NULL) {
	468	SM2err(SM2_F_SM2_VERIFY, ERR_R_BN_LIB);
	469	goto done;
	470	}
3d328a44	471
2167239a	472	ret = sm2_sig_verify(eckey, s, e);
3d328a44 JL	473
	474	done:
	475	OPENSSL_free(der);
	476	BN_free(e);
	477	ECDSA_SIG_free(s);
	478	return ret;
	479	}