2 * Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright 2017 Ribose Inc. All Rights Reserved.
4 * Ported from Ribose contributions from Botan.
6 * Licensed under the Apache License 2.0 (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
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>
22 int sm2_compute_z_digest(uint8_t *out
,
29 const EC_GROUP
*group
= EC_KEY_get0_group(key
);
31 EVP_MD_CTX
*hash
= NULL
;
44 hash
= EVP_MD_CTX_new();
45 ctx
= BN_CTX_new_ex(ec_key_get_libctx(key
));
46 if (hash
== NULL
|| ctx
== NULL
) {
47 SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST
, ERR_R_MALLOC_FAILURE
);
60 SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST
, ERR_R_MALLOC_FAILURE
);
64 if (!EVP_DigestInit(hash
, digest
)) {
65 SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST
, ERR_R_EVP_LIB
);
69 /* Z = h(ENTL || ID || a || b || xG || yG || xA || yA) */
71 if (id_len
>= (UINT16_MAX
/ 8)) {
73 SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST
, SM2_R_ID_TOO_LARGE
);
77 entl
= (uint16_t)(8 * id_len
);
80 if (!EVP_DigestUpdate(hash
, &e_byte
, 1)) {
81 SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST
, ERR_R_EVP_LIB
);
85 if (!EVP_DigestUpdate(hash
, &e_byte
, 1)) {
86 SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST
, ERR_R_EVP_LIB
);
90 if (id_len
> 0 && !EVP_DigestUpdate(hash
, id
, id_len
)) {
91 SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST
, ERR_R_EVP_LIB
);
95 if (!EC_GROUP_get_curve(group
, p
, a
, b
, ctx
)) {
96 SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST
, ERR_R_EC_LIB
);
100 p_bytes
= BN_num_bytes(p
);
101 buf
= OPENSSL_zalloc(p_bytes
);
103 SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST
, ERR_R_MALLOC_FAILURE
);
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
),
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
),
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
)) {
126 SM2err(SM2_F_SM2_COMPUTE_Z_DIGEST
, ERR_R_INTERNAL_ERROR
);
135 EVP_MD_CTX_free(hash
);
139 static BIGNUM
*sm2_compute_msg_hash(const EVP_MD
*digest
,
143 const uint8_t *msg
, size_t msg_len
)
145 EVP_MD_CTX
*hash
= EVP_MD_CTX_new();
146 const int md_size
= EVP_MD_size(digest
);
149 EVP_MD
*fetched_digest
= NULL
;
150 OPENSSL_CTX
*libctx
= ec_key_get_libctx(key
);
151 const char *propq
= ec_key_get0_propq(key
);
154 SM2err(SM2_F_SM2_COMPUTE_MSG_HASH
, SM2_R_INVALID_DIGEST
);
158 z
= OPENSSL_zalloc(md_size
);
159 if (hash
== NULL
|| z
== NULL
) {
160 SM2err(SM2_F_SM2_COMPUTE_MSG_HASH
, ERR_R_MALLOC_FAILURE
);
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
);
170 if (!sm2_compute_z_digest(z
, fetched_digest
, id
, id_len
, key
)) {
171 /* SM2err already called */
175 if (!EVP_DigestInit(hash
, fetched_digest
)
176 || !EVP_DigestUpdate(hash
, z
, md_size
)
177 || !EVP_DigestUpdate(hash
, msg
, msg_len
)
178 /* reuse z buffer to hold H(Z || M) */
179 || !EVP_DigestFinal(hash
, z
, NULL
)) {
180 SM2err(SM2_F_SM2_COMPUTE_MSG_HASH
, ERR_R_EVP_LIB
);
184 e
= BN_bin2bn(z
, md_size
, NULL
);
186 SM2err(SM2_F_SM2_COMPUTE_MSG_HASH
, ERR_R_INTERNAL_ERROR
);
189 EVP_MD_free(fetched_digest
);
191 EVP_MD_CTX_free(hash
);
195 static ECDSA_SIG
*sm2_sig_gen(const EC_KEY
*key
, const BIGNUM
*e
)
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
);
200 ECDSA_SIG
*sig
= NULL
;
209 OPENSSL_CTX
*libctx
= ec_key_get_libctx(key
);
211 kG
= EC_POINT_new(group
);
212 ctx
= BN_CTX_new_ex(libctx
);
213 if (kG
== NULL
|| ctx
== NULL
) {
214 SM2err(SM2_F_SM2_SIG_GEN
, ERR_R_MALLOC_FAILURE
);
220 rk
= BN_CTX_get(ctx
);
221 x1
= BN_CTX_get(ctx
);
222 tmp
= BN_CTX_get(ctx
);
224 SM2err(SM2_F_SM2_SIG_GEN
, ERR_R_MALLOC_FAILURE
);
229 * These values are returned and so should not be allocated out of the
235 if (r
== NULL
|| s
== NULL
) {
236 SM2err(SM2_F_SM2_SIG_GEN
, ERR_R_MALLOC_FAILURE
);
241 if (!BN_priv_rand_range_ex(k
, order
, ctx
)) {
242 SM2err(SM2_F_SM2_SIG_GEN
, ERR_R_INTERNAL_ERROR
);
246 if (!EC_POINT_mul(group
, kG
, k
, NULL
, NULL
, ctx
)
247 || !EC_POINT_get_affine_coordinates(group
, kG
, x1
, NULL
,
249 || !BN_mod_add(r
, e
, x1
, order
, ctx
)) {
250 SM2err(SM2_F_SM2_SIG_GEN
, ERR_R_INTERNAL_ERROR
);
254 /* try again if r == 0 or r+k == n */
258 if (!BN_add(rk
, r
, k
)) {
259 SM2err(SM2_F_SM2_SIG_GEN
, ERR_R_INTERNAL_ERROR
);
263 if (BN_cmp(rk
, order
) == 0)
266 if (!BN_add(s
, dA
, BN_value_one())
267 || !ec_group_do_inverse_ord(group
, s
, s
, ctx
)
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
);
275 sig
= ECDSA_SIG_new();
277 SM2err(SM2_F_SM2_SIG_GEN
, ERR_R_MALLOC_FAILURE
);
281 /* takes ownership of r and s */
282 ECDSA_SIG_set0(sig
, r
, s
);
297 static int sm2_sig_verify(const EC_KEY
*key
, const ECDSA_SIG
*sig
,
301 const EC_GROUP
*group
= EC_KEY_get0_group(key
);
302 const BIGNUM
*order
= EC_GROUP_get0_order(group
);
307 const BIGNUM
*r
= NULL
;
308 const BIGNUM
*s
= NULL
;
309 OPENSSL_CTX
*libctx
= ec_key_get_libctx(key
);
311 ctx
= BN_CTX_new_ex(libctx
);
312 pt
= EC_POINT_new(group
);
313 if (ctx
== NULL
|| pt
== NULL
) {
314 SM2err(SM2_F_SM2_SIG_VERIFY
, ERR_R_MALLOC_FAILURE
);
320 x1
= BN_CTX_get(ctx
);
322 SM2err(SM2_F_SM2_SIG_VERIFY
, ERR_R_MALLOC_FAILURE
);
327 * B1: verify whether r' in [1,n-1], verification failed if not
328 * B2: verify whether s' in [1,n-1], verification failed if not
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
333 * B7: calculate R=(e'+x1') modn, verification pass if yes, otherwise failed
336 ECDSA_SIG_get0(sig
, &r
, &s
);
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) {
342 SM2err(SM2_F_SM2_SIG_VERIFY
, SM2_R_BAD_SIGNATURE
);
346 if (!BN_mod_add(t
, r
, s
, order
, ctx
)) {
347 SM2err(SM2_F_SM2_SIG_VERIFY
, ERR_R_BN_LIB
);
352 SM2err(SM2_F_SM2_SIG_VERIFY
, SM2_R_BAD_SIGNATURE
);
356 if (!EC_POINT_mul(group
, pt
, s
, EC_KEY_get0_public_key(key
), t
, ctx
)
357 || !EC_POINT_get_affine_coordinates(group
, pt
, x1
, NULL
, ctx
)) {
358 SM2err(SM2_F_SM2_SIG_VERIFY
, ERR_R_EC_LIB
);
362 if (!BN_mod_add(t
, e
, x1
, order
, ctx
)) {
363 SM2err(SM2_F_SM2_SIG_VERIFY
, ERR_R_BN_LIB
);
367 if (BN_cmp(r
, t
) == 0)
376 ECDSA_SIG
*sm2_do_sign(const EC_KEY
*key
,
377 const EVP_MD
*digest
,
380 const uint8_t *msg
, size_t msg_len
)
383 ECDSA_SIG
*sig
= NULL
;
385 e
= sm2_compute_msg_hash(digest
, key
, id
, id_len
, msg
, msg_len
);
387 /* SM2err already called */
391 sig
= sm2_sig_gen(key
, e
);
398 int sm2_do_verify(const EC_KEY
*key
,
399 const EVP_MD
*digest
,
400 const ECDSA_SIG
*sig
,
403 const uint8_t *msg
, size_t msg_len
)
408 e
= sm2_compute_msg_hash(digest
, key
, id
, id_len
, msg
, msg_len
);
410 /* SM2err already called */
414 ret
= sm2_sig_verify(key
, sig
, e
);
421 int sm2_internal_sign(const unsigned char *dgst
, int dgstlen
,
422 unsigned char *sig
, unsigned int *siglen
, EC_KEY
*eckey
)
429 e
= BN_bin2bn(dgst
, dgstlen
, NULL
);
431 SM2err(SM2_F_SM2_INTERNAL_SIGN
, ERR_R_BN_LIB
);
435 s
= sm2_sig_gen(eckey
, e
);
437 SM2err(SM2_F_SM2_INTERNAL_SIGN
, ERR_R_INTERNAL_ERROR
);
441 sigleni
= i2d_ECDSA_SIG(s
, &sig
);
443 SM2err(SM2_F_SM2_INTERNAL_SIGN
, ERR_R_INTERNAL_ERROR
);
446 *siglen
= (unsigned int)sigleni
;
456 int sm2_internal_verify(const unsigned char *dgst
, int dgstlen
,
457 const unsigned char *sig
, int sig_len
, EC_KEY
*eckey
)
461 const unsigned char *p
= sig
;
462 unsigned char *der
= NULL
;
468 SM2err(SM2_F_SM2_INTERNAL_VERIFY
, ERR_R_MALLOC_FAILURE
);
471 if (d2i_ECDSA_SIG(&s
, &p
, sig_len
) == NULL
) {
472 SM2err(SM2_F_SM2_INTERNAL_VERIFY
, SM2_R_INVALID_ENCODING
);
475 /* Ensure signature uses DER and doesn't have trailing garbage */
476 derlen
= i2d_ECDSA_SIG(s
, &der
);
477 if (derlen
!= sig_len
|| memcmp(sig
, der
, derlen
) != 0) {
478 SM2err(SM2_F_SM2_INTERNAL_VERIFY
, SM2_R_INVALID_ENCODING
);
482 e
= BN_bin2bn(dgst
, dgstlen
, NULL
);
484 SM2err(SM2_F_SM2_INTERNAL_VERIFY
, ERR_R_BN_LIB
);
488 ret
= sm2_sig_verify(eckey
, s
, e
);