/src/irssi/subprojects/openssl-1.1.1l/crypto/sm2/sm2_sign.c

Source (jump to first uncovered line)
/*
 * Copyright 2017-2019 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 "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();
    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: 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_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;
}

Coverage Report

Created: 2025-07-01 06:23

Line	Count	Source (jump to first uncovered line)
1		/*
2		* Copyright 2017-2019 The OpenSSL Project Authors. All Rights Reserved.
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
12		#include "crypto/sm2.h"
13		#include "crypto/sm2err.h"
14		#include "crypto/ec.h" /* ec_group_do_inverse_ord() */
15		#include "internal/numbers.h"
16		#include <openssl/err.h>
17		#include <openssl/evp.h>
18		#include <openssl/err.h>
19		#include <openssl/bn.h>
20		#include <string.h>
21
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)
27	0	{
28	0	int rc = 0;
29	0	const EC_GROUP *group = EC_KEY_get0_group(key);
30	0	BN_CTX *ctx = NULL;
31	0	EVP_MD_CTX *hash = NULL;
32	0	BIGNUM *p = NULL;
33	0	BIGNUM *a = NULL;
34	0	BIGNUM *b = NULL;
35	0	BIGNUM *xG = NULL;
36	0	BIGNUM *yG = NULL;
37	0	BIGNUM *xA = NULL;
38	0	BIGNUM *yA = NULL;
39	0	int p_bytes = 0;
40	0	uint8_t *buf = NULL;
41	0	uint16_t entl = 0;
42	0	uint8_t e_byte = 0;
43
44	0	hash = EVP_MD_CTX_new();
45	0	ctx = BN_CTX_new();
46	0	if (hash == NULL \|\| ctx == NULL) {
47	0	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_MALLOC_FAILURE);
48	0	goto done;
49	0	}
50
51	0	p = BN_CTX_get(ctx);
52	0	a = BN_CTX_get(ctx);
53	0	b = BN_CTX_get(ctx);
54	0	xG = BN_CTX_get(ctx);
55	0	yG = BN_CTX_get(ctx);
56	0	xA = BN_CTX_get(ctx);
57	0	yA = BN_CTX_get(ctx);
58
59	0	if (yA == NULL) {
60	0	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_MALLOC_FAILURE);
61	0	goto done;
62	0	}
63
64	0	if (!EVP_DigestInit(hash, digest)) {
65	0	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_EVP_LIB);
66	0	goto done;
67	0	}
68
69		/* Z = h(ENTL \|\| ID \|\| a \|\| b \|\| xG \|\| yG \|\| xA \|\| yA) */
70
71	0	if (id_len >= (UINT16_MAX / 8)) {
72		/* too large */
73	0	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, SM2_R_ID_TOO_LARGE);
74	0	goto done;
75	0	}
76
77	0	entl = (uint16_t)(8 * id_len);
78
79	0	e_byte = entl >> 8;
80	0	if (!EVP_DigestUpdate(hash, &e_byte, 1)) {
81	0	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_EVP_LIB);
82	0	goto done;
83	0	}
84	0	e_byte = entl & 0xFF;
85	0	if (!EVP_DigestUpdate(hash, &e_byte, 1)) {
86	0	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_EVP_LIB);
87	0	goto done;
88	0	}
89
90	0	if (id_len > 0 && !EVP_DigestUpdate(hash, id, id_len)) {
91	0	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_EVP_LIB);
92	0	goto done;
93	0	}
94
95	0	if (!EC_GROUP_get_curve(group, p, a, b, ctx)) {
96	0	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_EC_LIB);
97	0	goto done;
98	0	}
99
100	0	p_bytes = BN_num_bytes(p);
101	0	buf = OPENSSL_zalloc(p_bytes);
102	0	if (buf == NULL) {
103	0	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_MALLOC_FAILURE);
104	0	goto done;
105	0	}
106
107	0	if (BN_bn2binpad(a, buf, p_bytes) < 0
108	0	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
109	0	\|\| BN_bn2binpad(b, buf, p_bytes) < 0
110	0	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
111	0	\|\| !EC_POINT_get_affine_coordinates(group,
112	0	EC_GROUP_get0_generator(group),
113	0	xG, yG, ctx)
114	0	\|\| BN_bn2binpad(xG, buf, p_bytes) < 0
115	0	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
116	0	\|\| BN_bn2binpad(yG, buf, p_bytes) < 0
117	0	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
118	0	\|\| !EC_POINT_get_affine_coordinates(group,
119	0	EC_KEY_get0_public_key(key),
120	0	xA, yA, ctx)
121	0	\|\| BN_bn2binpad(xA, buf, p_bytes) < 0
122	0	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
123	0	\|\| BN_bn2binpad(yA, buf, p_bytes) < 0
124	0	\|\| !EVP_DigestUpdate(hash, buf, p_bytes)
125	0	\|\| !EVP_DigestFinal(hash, out, NULL)) {
126	0	SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST, ERR_R_INTERNAL_ERROR);
127	0	goto done;
128	0	}
129
130	0	rc = 1;
131
132	0	done:
133	0	OPENSSL_free(buf);
134	0	BN_CTX_free(ctx);
135	0	EVP_MD_CTX_free(hash);
136	0	return rc;
137	0	}
138
139		static BIGNUM sm2_compute_msg_hash(const EVP_MD digest,
140		const EC_KEY *key,
141		const uint8_t *id,
142		const size_t id_len,
143		const uint8_t *msg, size_t msg_len)
144	0	{
145	0	EVP_MD_CTX *hash = EVP_MD_CTX_new();
146	0	const int md_size = EVP_MD_size(digest);
147	0	uint8_t *z = NULL;
148	0	BIGNUM *e = NULL;
149
150	0	if (md_size < 0) {
151	0	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, SM2_R_INVALID_DIGEST);
152	0	goto done;
153	0	}
154
155	0	z = OPENSSL_zalloc(md_size);
156	0	if (hash == NULL \|\| z == NULL) {
157	0	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_MALLOC_FAILURE);
158	0	goto done;
159	0	}
160
161	0	if (!sm2_compute_z_digest(z, digest, id, id_len, key)) {
162		/* SM2err already called */
163	0	goto done;
164	0	}
165
166	0	if (!EVP_DigestInit(hash, digest)
167	0	\|\| !EVP_DigestUpdate(hash, z, md_size)
168	0	\|\| !EVP_DigestUpdate(hash, msg, msg_len)
169		/* reuse z buffer to hold H(Z \|\| M) */
170	0	\|\| !EVP_DigestFinal(hash, z, NULL)) {
171	0	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_EVP_LIB);
172	0	goto done;
173	0	}
174
175	0	e = BN_bin2bn(z, md_size, NULL);
176	0	if (e == NULL)
177	0	SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_INTERNAL_ERROR);
178
179	0	done:
180	0	OPENSSL_free(z);
181	0	EVP_MD_CTX_free(hash);
182	0	return e;
183	0	}
184
185		static ECDSA_SIG sm2_sig_gen(const EC_KEY key, const BIGNUM *e)
186	0	{
187	0	const BIGNUM *dA = EC_KEY_get0_private_key(key);
188	0	const EC_GROUP *group = EC_KEY_get0_group(key);
189	0	const BIGNUM *order = EC_GROUP_get0_order(group);
190	0	ECDSA_SIG *sig = NULL;
191	0	EC_POINT *kG = NULL;
192	0	BN_CTX *ctx = NULL;
193	0	BIGNUM *k = NULL;
194	0	BIGNUM *rk = NULL;
195	0	BIGNUM *r = NULL;
196	0	BIGNUM *s = NULL;
197	0	BIGNUM *x1 = NULL;
198	0	BIGNUM *tmp = NULL;
199
200	0	kG = EC_POINT_new(group);
201	0	ctx = BN_CTX_new();
202	0	if (kG == NULL \|\| ctx == NULL) {
203	0	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
204	0	goto done;
205	0	}
206
207	0	BN_CTX_start(ctx);
208	0	k = BN_CTX_get(ctx);
209	0	rk = BN_CTX_get(ctx);
210	0	x1 = BN_CTX_get(ctx);
211	0	tmp = BN_CTX_get(ctx);
212	0	if (tmp == NULL) {
213	0	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
214	0	goto done;
215	0	}
216
217		/*
218		* These values are returned and so should not be allocated out of the
219		* context
220		*/
221	0	r = BN_new();
222	0	s = BN_new();
223
224	0	if (r == NULL \|\| s == NULL) {
225	0	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
226	0	goto done;
227	0	}
228
229	0	for (;;) {
230	0	if (!BN_priv_rand_range(k, order)) {
231	0	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_INTERNAL_ERROR);
232	0	goto done;
233	0	}
234
235	0	if (!EC_POINT_mul(group, kG, k, NULL, NULL, ctx)
236	0	\|\| !EC_POINT_get_affine_coordinates(group, kG, x1, NULL,
237	0	ctx)
238	0	\|\| !BN_mod_add(r, e, x1, order, ctx)) {
239	0	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_INTERNAL_ERROR);
240	0	goto done;
241	0	}
242
243		/* try again if r == 0 or r+k == n */
244	0	if (BN_is_zero(r))
245	0	continue;
246
247	0	if (!BN_add(rk, r, k)) {
248	0	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_INTERNAL_ERROR);
249	0	goto done;
250	0	}
251
252	0	if (BN_cmp(rk, order) == 0)
253	0	continue;
254
255	0	if (!BN_add(s, dA, BN_value_one())
256	0	\|\| !ec_group_do_inverse_ord(group, s, s, ctx)
257	0	\|\| !BN_mod_mul(tmp, dA, r, order, ctx)
258	0	\|\| !BN_sub(tmp, k, tmp)
259	0	\|\| !BN_mod_mul(s, s, tmp, order, ctx)) {
260	0	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_BN_LIB);
261	0	goto done;
262	0	}
263
264	0	sig = ECDSA_SIG_new();
265	0	if (sig == NULL) {
266	0	SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
267	0	goto done;
268	0	}
269
270		/* takes ownership of r and s */
271	0	ECDSA_SIG_set0(sig, r, s);
272	0	break;
273	0	}
274
275	0	done:
276	0	if (sig == NULL) {
277	0	BN_free(r);
278	0	BN_free(s);
279	0	}
280
281	0	BN_CTX_free(ctx);
282	0	EC_POINT_free(kG);
283	0	return sig;
284	0	}
285
286		static int sm2_sig_verify(const EC_KEY key, const ECDSA_SIG sig,
287		const BIGNUM *e)
288	0	{
289	0	int ret = 0;
290	0	const EC_GROUP *group = EC_KEY_get0_group(key);
291	0	const BIGNUM *order = EC_GROUP_get0_order(group);
292	0	BN_CTX *ctx = NULL;
293	0	EC_POINT *pt = NULL;
294	0	BIGNUM *t = NULL;
295	0	BIGNUM *x1 = NULL;
296	0	const BIGNUM *r = NULL;
297	0	const BIGNUM *s = NULL;
298
299	0	ctx = BN_CTX_new();
300	0	pt = EC_POINT_new(group);
301	0	if (ctx == NULL \|\| pt == NULL) {
302	0	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_MALLOC_FAILURE);
303	0	goto done;
304	0	}
305
306	0	BN_CTX_start(ctx);
307	0	t = BN_CTX_get(ctx);
308	0	x1 = BN_CTX_get(ctx);
309	0	if (x1 == NULL) {
310	0	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_MALLOC_FAILURE);
311	0	goto done;
312	0	}
313
314		/*
315		* B1: verify whether r' in [1,n-1], verification failed if not
316		* B2: verify 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, verification pass if yes, otherwise failed
322		*/
323
324	0	ECDSA_SIG_get0(sig, &r, &s);
325
326	0	if (BN_cmp(r, BN_value_one()) < 0
327	0	\|\| BN_cmp(s, BN_value_one()) < 0
328	0	\|\| BN_cmp(order, r) <= 0
329	0	\|\| BN_cmp(order, s) <= 0) {
330	0	SM2err(SM2_F_SM2_SIG_VERIFY, SM2_R_BAD_SIGNATURE);
331	0	goto done;
332	0	}
333
334	0	if (!BN_mod_add(t, r, s, order, ctx)) {
335	0	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_BN_LIB);
336	0	goto done;
337	0	}
338
339	0	if (BN_is_zero(t)) {
340	0	SM2err(SM2_F_SM2_SIG_VERIFY, SM2_R_BAD_SIGNATURE);
341	0	goto done;
342	0	}
343
344	0	if (!EC_POINT_mul(group, pt, s, EC_KEY_get0_public_key(key), t, ctx)
345	0	\|\| !EC_POINT_get_affine_coordinates(group, pt, x1, NULL, ctx)) {
346	0	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_EC_LIB);
347	0	goto done;
348	0	}
349
350	0	if (!BN_mod_add(t, e, x1, order, ctx)) {
351	0	SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_BN_LIB);
352	0	goto done;
353	0	}
354
355	0	if (BN_cmp(r, t) == 0)
356	0	ret = 1;
357
358	0	done:
359	0	EC_POINT_free(pt);
360	0	BN_CTX_free(ctx);
361	0	return ret;
362	0	}
363
364		ECDSA_SIG sm2_do_sign(const EC_KEY key,
365		const EVP_MD *digest,
366		const uint8_t *id,
367		const size_t id_len,
368		const uint8_t *msg, size_t msg_len)
369	0	{
370	0	BIGNUM *e = NULL;
371	0	ECDSA_SIG *sig = NULL;
372
373	0	e = sm2_compute_msg_hash(digest, key, id, id_len, msg, msg_len);
374	0	if (e == NULL) {
375		/* SM2err already called */
376	0	goto done;
377	0	}
378
379	0	sig = sm2_sig_gen(key, e);
380
381	0	done:
382	0	BN_free(e);
383	0	return sig;
384	0	}
385
386		int sm2_do_verify(const EC_KEY *key,
387		const EVP_MD *digest,
388		const ECDSA_SIG *sig,
389		const uint8_t *id,
390		const size_t id_len,
391		const uint8_t *msg, size_t msg_len)
392	0	{
393	0	BIGNUM *e = NULL;
394	0	int ret = 0;
395
396	0	e = sm2_compute_msg_hash(digest, key, id, id_len, msg, msg_len);
397	0	if (e == NULL) {
398		/* SM2err already called */
399	0	goto done;
400	0	}
401
402	0	ret = sm2_sig_verify(key, sig, e);
403
404	0	done:
405	0	BN_free(e);
406	0	return ret;
407	0	}
408
409		int sm2_sign(const unsigned char *dgst, int dgstlen,
410		unsigned char sig, unsigned int siglen, EC_KEY *eckey)
411	0	{
412	0	BIGNUM *e = NULL;
413	0	ECDSA_SIG *s = NULL;
414	0	int sigleni;
415	0	int ret = -1;
416
417	0	e = BN_bin2bn(dgst, dgstlen, NULL);
418	0	if (e == NULL) {
419	0	SM2err(SM2_F_SM2_SIGN, ERR_R_BN_LIB);
420	0	goto done;
421	0	}
422
423	0	s = sm2_sig_gen(eckey, e);
424
425	0	sigleni = i2d_ECDSA_SIG(s, &sig);
426	0	if (sigleni < 0) {
427	0	SM2err(SM2_F_SM2_SIGN, ERR_R_INTERNAL_ERROR);
428	0	goto done;
429	0	}
430	0	*siglen = (unsigned int)sigleni;
431
432	0	ret = 1;
433
434	0	done:
435	0	ECDSA_SIG_free(s);
436	0	BN_free(e);
437	0	return ret;
438	0	}
439
440		int sm2_verify(const unsigned char *dgst, int dgstlen,
441		const unsigned char sig, int sig_len, EC_KEY eckey)
442	0	{
443	0	ECDSA_SIG *s = NULL;
444	0	BIGNUM *e = NULL;
445	0	const unsigned char *p = sig;
446	0	unsigned char *der = NULL;
447	0	int derlen = -1;
448	0	int ret = -1;
449
450	0	s = ECDSA_SIG_new();
451	0	if (s == NULL) {
452	0	SM2err(SM2_F_SM2_VERIFY, ERR_R_MALLOC_FAILURE);
453	0	goto done;
454	0	}
455	0	if (d2i_ECDSA_SIG(&s, &p, sig_len) == NULL) {
456	0	SM2err(SM2_F_SM2_VERIFY, SM2_R_INVALID_ENCODING);
457	0	goto done;
458	0	}
459		/* Ensure signature uses DER and doesn't have trailing garbage */
460	0	derlen = i2d_ECDSA_SIG(s, &der);
461	0	if (derlen != sig_len \|\| memcmp(sig, der, derlen) != 0) {
462	0	SM2err(SM2_F_SM2_VERIFY, SM2_R_INVALID_ENCODING);
463	0	goto done;
464	0	}
465
466	0	e = BN_bin2bn(dgst, dgstlen, NULL);
467	0	if (e == NULL) {
468	0	SM2err(SM2_F_SM2_VERIFY, ERR_R_BN_LIB);
469	0	goto done;
470	0	}
471
472	0	ret = sm2_sig_verify(eckey, s, e);
473
474	0	done:
475	0	OPENSSL_free(der);
476	0	BN_free(e);
477	0	ECDSA_SIG_free(s);
478	0	return ret;
479	0	}