[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 "crypto/sm2.h"
#include "crypto/sm2err.h"
#include "crypto/ec.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_ex(ec_key_get_libctx(key));
    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;
    EVP_MD *fetched_digest = NULL;
    OPENSSL_CTX *libctx = ec_key_get_libctx(key);
    const char *propq = ec_key_get0_propq(key);

    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;
    }

    fetched_digest = EVP_MD_fetch(libctx, EVP_MD_name(digest), propq);
    if (fetched_digest == NULL) {
        SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_INTERNAL_ERROR);
        goto done;
    }

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

    if (!EVP_DigestInit(hash, fetched_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:
    EVP_MD_free(fetched_digest);
    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;
    OPENSSL_CTX *libctx = ec_key_get_libctx(key);

    kG = EC_POINT_new(group);
    ctx = BN_CTX_new_ex(libctx);
    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_ex(k, order, ctx)) {
            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;
    OPENSSL_CTX *libctx = ec_key_get_libctx(key);

    ctx = BN_CTX_new_ex(libctx);
    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: verify 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, verification 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_internal_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_INTERNAL_SIGN, ERR_R_BN_LIB);
       goto done;
    }

    s = sm2_sig_gen(eckey, e);
    if (s == NULL) {
        SM2err(SM2_F_SM2_INTERNAL_SIGN, ERR_R_INTERNAL_ERROR);
        goto done;
    }

    sigleni = i2d_ECDSA_SIG(s, &sig);
    if (sigleni < 0) {
       SM2err(SM2_F_SM2_INTERNAL_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_internal_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_INTERNAL_VERIFY, ERR_R_MALLOC_FAILURE);
        goto done;
    }
    if (d2i_ECDSA_SIG(&s, &p, sig_len) == NULL) {
        SM2err(SM2_F_SM2_INTERNAL_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_INTERNAL_VERIFY, SM2_R_INVALID_ENCODING);
        goto done;
    }

    e = BN_bin2bn(dgst, dgstlen, NULL);
    if (e == NULL) {
        SM2err(SM2_F_SM2_INTERNAL_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
25f2138b DMSP	12	#include "crypto/sm2.h"
	13	#include "crypto/sm2err.h"
	14	#include "crypto/ec.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();
5ccada09	45	ctx = BN_CTX_new_ex(ec_key_get_libctx(key));
5bd0abe7	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	148	BIGNUM *e = NULL;
5ccada09 SL	149	EVP_MD *fetched_digest = NULL;
	150	OPENSSL_CTX *libctx = ec_key_get_libctx(key);
	151	const char *propq = ec_key_get0_propq(key);
3d328a44	152
3e0076c2 MC	153	if (md_size < 0) {
3e0076c2 MC	154	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, SM2_R_INVALID_DIGEST);
3d328a44	155	goto done;
245be530	156	}
3d328a44	157
4803717f PY	158	z = OPENSSL_zalloc(md_size);
4803717f PY	159	if (hash == NULL \|\| z == NULL) {
3e0076c2	160	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_MALLOC_FAILURE);
3d328a44	161	goto done;
245be530	162	}
3d328a44	163
5ccada09 SL	164	fetched_digest = EVP_MD_fetch(libctx, EVP_MD_name(digest), propq);
	165	if (fetched_digest == NULL) {
	166	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_INTERNAL_ERROR);
	167	goto done;
	168	}
	169
	170	if (!sm2_compute_z_digest(z, fetched_digest, id, id_len, key)) {
245be530	171	/* SM2err already called */
3d328a44	172	goto done;
245be530	173	}
3d328a44	174
5ccada09	175	if (!EVP_DigestInit(hash, fetched_digest)
4803717f	176	\|\| !EVP_DigestUpdate(hash, z, md_size)
245be530	177	\|\| !EVP_DigestUpdate(hash, msg, msg_len)
4803717f PY	178	/* reuse z buffer to hold H(Z \|\| M) */
4803717f PY	179	\|\| !EVP_DigestFinal(hash, z, NULL)) {
2398404e	180	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_EVP_LIB);
3d328a44	181	goto done;
245be530	182	}
3d328a44	183
4803717f	184	e = BN_bin2bn(z, md_size, NULL);
245be530 MC	185	if (e == NULL)
245be530 MC	186	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_INTERNAL_ERROR);
3d328a44 JL	187
3d328a44 JL	188	done:
5ccada09	189	EVP_MD_free(fetched_digest);
4803717f	190	OPENSSL_free(z);
3d328a44 JL	191	EVP_MD_CTX_free(hash);
	192	return e;
	193	}
	194
2167239a	195	static ECDSA_SIG sm2_sig_gen(const EC_KEY key, const BIGNUM *e)
3d328a44 JL	196	{
	197	const BIGNUM *dA = EC_KEY_get0_private_key(key);
	198	const EC_GROUP *group = EC_KEY_get0_group(key);
	199	const BIGNUM *order = EC_GROUP_get0_order(group);
3d328a44 JL	200	ECDSA_SIG *sig = NULL;
	201	EC_POINT *kG = NULL;
	202	BN_CTX *ctx = NULL;
	203	BIGNUM *k = NULL;
	204	BIGNUM *rk = NULL;
	205	BIGNUM *r = NULL;
	206	BIGNUM *s = NULL;
	207	BIGNUM *x1 = NULL;
	208	BIGNUM *tmp = NULL;
5ccada09	209	OPENSSL_CTX *libctx = ec_key_get_libctx(key);
3d328a44 JL	210
3d328a44 JL	211	kG = EC_POINT_new(group);
5ccada09	212	ctx = BN_CTX_new_ex(libctx);
245be530	213	if (kG == NULL \|\| ctx == NULL) {
2398404e	214	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
3d328a44	215	goto done;
245be530	216	}
3d328a44	217
245be530	218	BN_CTX_start(ctx);
3d328a44 JL	219	k = BN_CTX_get(ctx);
	220	rk = BN_CTX_get(ctx);
	221	x1 = BN_CTX_get(ctx);
	222	tmp = BN_CTX_get(ctx);
245be530 MC	223	if (tmp == NULL) {
245be530 MC	224	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
3d328a44	225	goto done;
245be530	226	}
3d328a44	227
245be530 MC	228	/*
	229	* These values are returned and so should not be allocated out of the
	230	* context
	231	*/
3d328a44 JL	232	r = BN_new();
	233	s = BN_new();
	234
245be530	235	if (r == NULL \|\| s == NULL) {
2398404e	236	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
3d328a44	237	goto done;
245be530	238	}
3d328a44 JL	239
3d328a44 JL	240	for (;;) {
5ccada09	241	if (!BN_priv_rand_range_ex(k, order, ctx)) {
245be530	242	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_INTERNAL_ERROR);
9e4c9777	243	goto done;
245be530	244	}
3d328a44	245
245be530	246	if (!EC_POINT_mul(group, kG, k, NULL, NULL, ctx)
9cc570d4	247	\|\| !EC_POINT_get_affine_coordinates(group, kG, x1, NULL,
5bd0abe7	248	ctx)
245be530 MC	249	\|\| !BN_mod_add(r, e, x1, order, ctx)) {
245be530 MC	250	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_INTERNAL_ERROR);
3d328a44	251	goto done;
245be530	252	}
3d328a44 JL	253
	254	/* try again if r == 0 or r+k == n */
	255	if (BN_is_zero(r))
	256	continue;
	257
245be530 MC	258	if (!BN_add(rk, r, k)) {
	259	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_INTERNAL_ERROR);
	260	goto done;
	261	}
3d328a44 JL	262
	263	if (BN_cmp(rk, order) == 0)
	264	continue;
	265
245be530	266	if (!BN_add(s, dA, BN_value_one())
469c2c4a	267	\|\| !ec_group_do_inverse_ord(group, s, s, ctx)
245be530 MC	268	\|\| !BN_mod_mul(tmp, dA, r, order, ctx)
	269	\|\| !BN_sub(tmp, k, tmp)
	270	\|\| !BN_mod_mul(s, s, tmp, order, ctx)) {
	271	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_BN_LIB);
	272	goto done;
	273	}
3d328a44 JL	274
3d328a44 JL	275	sig = ECDSA_SIG_new();
245be530	276	if (sig == NULL) {
2398404e	277	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
3d328a44	278	goto done;
245be530	279	}
3d328a44 JL	280
	281	/* takes ownership of r and s */
	282	ECDSA_SIG_set0(sig, r, s);
	283	break;
	284	}
	285
	286	done:
3d328a44 JL	287	if (sig == NULL) {
	288	BN_free(r);
	289	BN_free(s);
	290	}
	291
	292	BN_CTX_free(ctx);
	293	EC_POINT_free(kG);
	294	return sig;
3d328a44 JL	295	}
3d328a44 JL	296
2167239a	297	static int sm2_sig_verify(const EC_KEY key, const ECDSA_SIG sig,
245be530	298	const BIGNUM *e)
3d328a44 JL	299	{
	300	int ret = 0;
	301	const EC_GROUP *group = EC_KEY_get0_group(key);
	302	const BIGNUM *order = EC_GROUP_get0_order(group);
	303	BN_CTX *ctx = NULL;
	304	EC_POINT *pt = NULL;
3d328a44 JL	305	BIGNUM *t = NULL;
	306	BIGNUM *x1 = NULL;
	307	const BIGNUM *r = NULL;
	308	const BIGNUM *s = NULL;
5ccada09	309	OPENSSL_CTX *libctx = ec_key_get_libctx(key);
3d328a44	310
5ccada09	311	ctx = BN_CTX_new_ex(libctx);
3d328a44	312	pt = EC_POINT_new(group);
245be530	313	if (ctx == NULL \|\| pt == NULL) {
2398404e	314	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_MALLOC_FAILURE);
3d328a44	315	goto done;
245be530	316	}
3d328a44 JL	317
3d328a44 JL	318	BN_CTX_start(ctx);
3d328a44 JL	319	t = BN_CTX_get(ctx);
3d328a44 JL	320	x1 = BN_CTX_get(ctx);
245be530 MC	321	if (x1 == NULL) {
	322	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_MALLOC_FAILURE);
	323	goto done;
	324	}
3d328a44 JL	325
3d328a44 JL	326	/*
245be530	327	* B1: verify whether r' in [1,n-1], verification failed if not
c2969ff6	328	* B2: verify whether s' in [1,n-1], verification failed if not
245be530 MC	329	* B3: set M'~=ZA \|\| M'
	330	* B4: calculate e'=Hv(M'~)
	331	* B5: calculate t = (r' + s') modn, verification failed if t=0
	332	* B6: calculate the point (x1', y1')=[s']G + [t]PA
c2969ff6	333	* B7: calculate R=(e'+x1') modn, verification pass if yes, otherwise failed
3d328a44 JL	334	*/
	335
	336	ECDSA_SIG_get0(sig, &r, &s);
	337
245be530 MC	338	if (BN_cmp(r, BN_value_one()) < 0
	339	\|\| BN_cmp(s, BN_value_one()) < 0
	340	\|\| BN_cmp(order, r) <= 0
	341	\|\| BN_cmp(order, s) <= 0) {
2398404e	342	SM2err(SM2_F_SM2_SIG_VERIFY, SM2_R_BAD_SIGNATURE);
3d328a44	343	goto done;
245be530	344	}
3d328a44	345
245be530	346	if (!BN_mod_add(t, r, s, order, ctx)) {
2398404e	347	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_BN_LIB);
3d328a44	348	goto done;
245be530	349	}
3d328a44	350
245be530	351	if (BN_is_zero(t)) {
2398404e	352	SM2err(SM2_F_SM2_SIG_VERIFY, SM2_R_BAD_SIGNATURE);
3d328a44	353	goto done;
245be530	354	}
3d328a44	355
245be530	356	if (!EC_POINT_mul(group, pt, s, EC_KEY_get0_public_key(key), t, ctx)
9cc570d4	357	\|\| !EC_POINT_get_affine_coordinates(group, pt, x1, NULL, ctx)) {
2398404e	358	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_EC_LIB);
3d328a44	359	goto done;
245be530	360	}
3d328a44	361
245be530	362	if (!BN_mod_add(t, e, x1, order, ctx)) {
2398404e	363	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_BN_LIB);
3d328a44	364	goto done;
245be530	365	}
3d328a44 JL	366
	367	if (BN_cmp(r, t) == 0)
	368	ret = 1;
	369
	370	done:
	371	EC_POINT_free(pt);
	372	BN_CTX_free(ctx);
	373	return ret;
	374	}
	375
2167239a	376	ECDSA_SIG sm2_do_sign(const EC_KEY key,
3d328a44	377	const EVP_MD *digest,
00433bad PY	378	const uint8_t *id,
	379	const size_t id_len,
	380	const uint8_t *msg, size_t msg_len)
3d328a44 JL	381	{
	382	BIGNUM *e = NULL;
	383	ECDSA_SIG *sig = NULL;
	384
00433bad	385	e = sm2_compute_msg_hash(digest, key, id, id_len, msg, msg_len);
245be530 MC	386	if (e == NULL) {
245be530 MC	387	/* SM2err already called */
3d328a44	388	goto done;
245be530	389	}
3d328a44	390
2167239a	391	sig = sm2_sig_gen(key, e);
3d328a44 JL	392
	393	done:
	394	BN_free(e);
	395	return sig;
	396	}
	397
2167239a	398	int sm2_do_verify(const EC_KEY *key,
3d328a44 JL	399	const EVP_MD *digest,
3d328a44 JL	400	const ECDSA_SIG *sig,
00433bad PY	401	const uint8_t *id,
	402	const size_t id_len,
	403	const uint8_t *msg, size_t msg_len)
3d328a44 JL	404	{
3d328a44 JL	405	BIGNUM *e = NULL;
245be530	406	int ret = 0;
3d328a44	407
00433bad	408	e = sm2_compute_msg_hash(digest, key, id, id_len, msg, msg_len);
245be530 MC	409	if (e == NULL) {
245be530 MC	410	/* SM2err already called */
3d328a44	411	goto done;
245be530	412	}
3d328a44	413
2167239a	414	ret = sm2_sig_verify(key, sig, e);
3d328a44 JL	415
	416	done:
	417	BN_free(e);
	418	return ret;
	419	}
	420
d0b79f86 PY	421	int sm2_internal_sign(const unsigned char *dgst, int dgstlen,
d0b79f86 PY	422	unsigned char sig, unsigned int siglen, EC_KEY *eckey)
3d328a44 JL	423	{
	424	BIGNUM *e = NULL;
	425	ECDSA_SIG *s = NULL;
245be530	426	int sigleni;
3d328a44 JL	427	int ret = -1;
3d328a44 JL	428
3d328a44	429	e = BN_bin2bn(dgst, dgstlen, NULL);
245be530	430	if (e == NULL) {
d0b79f86	431	SM2err(SM2_F_SM2_INTERNAL_SIGN, ERR_R_BN_LIB);
245be530 MC	432	goto done;
245be530 MC	433	}
3d328a44	434
2167239a	435	s = sm2_sig_gen(eckey, e);
5ccada09	436	if (s == NULL) {
d0b79f86	437	SM2err(SM2_F_SM2_INTERNAL_SIGN, ERR_R_INTERNAL_ERROR);
5ccada09 SL	438	goto done;
5ccada09 SL	439	}
3d328a44	440
245be530 MC	441	sigleni = i2d_ECDSA_SIG(s, &sig);
245be530 MC	442	if (sigleni < 0) {
d0b79f86	443	SM2err(SM2_F_SM2_INTERNAL_SIGN, ERR_R_INTERNAL_ERROR);
245be530 MC	444	goto done;
	445	}
	446	*siglen = (unsigned int)sigleni;
3d328a44	447
67cc2bae	448	ret = 1;
3d328a44 JL	449
	450	done:
	451	ECDSA_SIG_free(s);
	452	BN_free(e);
	453	return ret;
	454	}
	455
d0b79f86 PY	456	int sm2_internal_verify(const unsigned char *dgst, int dgstlen,
d0b79f86 PY	457	const unsigned char sig, int sig_len, EC_KEY eckey)
3d328a44 JL	458	{
	459	ECDSA_SIG *s = NULL;
	460	BIGNUM *e = NULL;
	461	const unsigned char *p = sig;
	462	unsigned char *der = NULL;
	463	int derlen = -1;
	464	int ret = -1;
	465
3d328a44	466	s = ECDSA_SIG_new();
245be530	467	if (s == NULL) {
d0b79f86	468	SM2err(SM2_F_SM2_INTERNAL_VERIFY, ERR_R_MALLOC_FAILURE);
3d328a44	469	goto done;
245be530 MC	470	}
245be530 MC	471	if (d2i_ECDSA_SIG(&s, &p, sig_len) == NULL) {
d0b79f86	472	SM2err(SM2_F_SM2_INTERNAL_VERIFY, SM2_R_INVALID_ENCODING);
3d328a44	473	goto done;
245be530	474	}
3d328a44 JL	475	/* Ensure signature uses DER and doesn't have trailing garbage */
3d328a44 JL	476	derlen = i2d_ECDSA_SIG(s, &der);
245be530	477	if (derlen != sig_len \|\| memcmp(sig, der, derlen) != 0) {
d0b79f86	478	SM2err(SM2_F_SM2_INTERNAL_VERIFY, SM2_R_INVALID_ENCODING);
3d328a44	479	goto done;
245be530	480	}
3d328a44 JL	481
3d328a44 JL	482	e = BN_bin2bn(dgst, dgstlen, NULL);
245be530	483	if (e == NULL) {
d0b79f86	484	SM2err(SM2_F_SM2_INTERNAL_VERIFY, ERR_R_BN_LIB);
245be530 MC	485	goto done;
245be530 MC	486	}
3d328a44	487
2167239a	488	ret = sm2_sig_verify(eckey, s, e);
3d328a44 JL	489
	490	done:
	491	OPENSSL_free(der);
	492	BN_free(e);
	493	ECDSA_SIG_free(s);
	494	return ret;
	495	}