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 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
12 #include "internal/sm2.h"
13 #include "internal/sm2err.h"
14 #include <openssl/err.h>
15 #include <openssl/evp.h>
16 #include <openssl/err.h>
17 #include <openssl/bn.h>
20 static BIGNUM *SM2_compute_msg_hash(const EVP_MD *digest,
23 const uint8_t *msg, size_t msg_len)
25 EVP_MD_CTX *hash = EVP_MD_CTX_new();
26 const int md_size = EVP_MD_size(digest);
27 uint8_t *za = OPENSSL_zalloc(md_size);
32 SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_MALLOC_FAILURE);
38 SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_MALLOC_FAILURE);
42 if (SM2_compute_userid_digest(za, digest, user_id, key) == 0)
45 if (EVP_DigestInit(hash, digest) == 0)
47 SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_EVP_LIB);
51 if (EVP_DigestUpdate(hash, za, md_size) == 0)
53 SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_EVP_LIB);
57 if (EVP_DigestUpdate(hash, msg, msg_len) == 0)
59 SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_EVP_LIB);
63 /* reuse za buffer to hold H(ZA || M) */
64 if (EVP_DigestFinal(hash, za, NULL) == 0)
66 SM2err(SM2_F_SM2_COMPUTE_MSG_HASH, ERR_R_EVP_LIB);
70 e = BN_bin2bn(za, md_size, NULL);
74 EVP_MD_CTX_free(hash);
79 ECDSA_SIG *SM2_sig_gen(const EC_KEY *key, const BIGNUM *e)
81 const BIGNUM *dA = EC_KEY_get0_private_key(key);
82 const EC_GROUP *group = EC_KEY_get0_group(key);
83 const BIGNUM *order = EC_GROUP_get0_order(group);
85 ECDSA_SIG *sig = NULL;
95 kG = EC_POINT_new(group);
98 SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
105 SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
112 rk = BN_CTX_get(ctx);
113 x1 = BN_CTX_get(ctx);
114 tmp = BN_CTX_get(ctx);
118 SM2err(SM2_F_SM2_SIG_GEN, ERR_R_BN_LIB);
122 /* These values are returned and so should not be allocated out of the context */
126 if (r == NULL || s == NULL)
128 SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
133 BN_priv_rand_range(k, order);
135 if (EC_POINT_mul(group, kG, k, NULL, NULL, ctx) == 0)
137 SM2err(SM2_F_SM2_SIG_GEN, ERR_R_EC_LIB);
141 if (EC_POINT_get_affine_coordinates_GFp(group, kG, x1, NULL, ctx) == 0)
143 SM2err(SM2_F_SM2_SIG_GEN, ERR_R_EC_LIB);
147 if (BN_mod_add(r, e, x1, order, ctx) == 0)
149 SM2err(SM2_F_SM2_SIG_GEN, ERR_R_BN_LIB);
153 /* try again if r == 0 or r+k == n */
159 if (BN_cmp(rk, order) == 0)
162 if(BN_add(s, dA, BN_value_one()) == 0)
164 SM2err(SM2_F_SM2_SIG_GEN, ERR_R_BN_LIB);
168 if(BN_mod_inverse(s, s, order, ctx) == 0)
170 SM2err(SM2_F_SM2_SIG_GEN, ERR_R_BN_LIB);
174 if(BN_mod_mul(tmp, dA, r, order, ctx) == 0)
176 SM2err(SM2_F_SM2_SIG_GEN, ERR_R_BN_LIB);
180 if(BN_sub(tmp, k, tmp) == 0)
182 SM2err(SM2_F_SM2_SIG_GEN, ERR_R_BN_LIB);
186 if(BN_mod_mul(s, s, tmp, order, ctx) == 0)
188 SM2err(SM2_F_SM2_SIG_GEN, ERR_R_BN_LIB);
192 sig = ECDSA_SIG_new();
196 SM2err(SM2_F_SM2_SIG_GEN, ERR_R_MALLOC_FAILURE);
200 /* takes ownership of r and s */
201 ECDSA_SIG_set0(sig, r, s);
219 int SM2_sig_verify(const EC_KEY *key, const ECDSA_SIG *sig, const BIGNUM *e)
222 const EC_GROUP *group = EC_KEY_get0_group(key);
223 const BIGNUM *order = EC_GROUP_get0_order(group);
229 const BIGNUM *r = NULL;
230 const BIGNUM *s = NULL;
235 SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_MALLOC_FAILURE);
239 pt = EC_POINT_new(group);
242 SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_MALLOC_FAILURE);
249 x1 = BN_CTX_get(ctx);
253 SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_MALLOC_FAILURE);
258 B1: verify whether r' in [1,n-1], verification failed if not
259 B2: vefify whether s' in [1,n-1], verification failed if not
261 B4: calculate e'=Hv(M'~)
262 B5: calculate t = (r' + s') modn, verification failed if t=0
263 B6: calculate the point (x1', y1')=[s']G + [t]PA
264 B7: calculate R=(e'+x1') modn, verfication pass if yes, otherwise failed
267 ECDSA_SIG_get0(sig, &r, &s);
269 if ((BN_cmp(r, BN_value_one()) < 0) || (BN_cmp(s, BN_value_one()) < 0))
271 SM2err(SM2_F_SM2_SIG_VERIFY, SM2_R_BAD_SIGNATURE);
275 if ((BN_cmp(order, r) <= 0) || (BN_cmp(order, s) <= 0))
277 SM2err(SM2_F_SM2_SIG_VERIFY, SM2_R_BAD_SIGNATURE);
281 if (BN_mod_add(t, r, s, order, ctx) == 0)
283 SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_BN_LIB);
287 if (BN_is_zero(t) == 1)
289 SM2err(SM2_F_SM2_SIG_VERIFY, SM2_R_BAD_SIGNATURE);
293 if (EC_POINT_mul(group, pt, s, EC_KEY_get0_public_key(key), t, ctx) == 0)
295 SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_EC_LIB);
299 if (EC_POINT_get_affine_coordinates_GFp(group, pt, x1, NULL, ctx) == 0)
301 SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_EC_LIB);
305 if (BN_mod_add(t, e, x1, order, ctx) == 0)
307 SM2err(SM2_F_SM2_SIG_VERIFY, ERR_R_BN_LIB);
311 if (BN_cmp(r, t) == 0)
320 ECDSA_SIG *SM2_do_sign(const EC_KEY *key,
321 const EVP_MD *digest,
322 const char *user_id, const uint8_t *msg, size_t msg_len)
325 ECDSA_SIG *sig = NULL;
327 e = SM2_compute_msg_hash(digest, key, user_id, msg, msg_len);
331 sig = SM2_sig_gen(key, e);
338 int SM2_do_verify(const EC_KEY *key,
339 const EVP_MD *digest,
340 const ECDSA_SIG *sig,
341 const char *user_id, const uint8_t *msg, size_t msg_len)
346 e = SM2_compute_msg_hash(digest, key, user_id, msg, msg_len);
350 ret = SM2_sig_verify(key, sig, e);
357 int SM2_sign(int type, const unsigned char *dgst, int dgstlen,
358 unsigned char *sig, unsigned int *siglen, EC_KEY *eckey)
364 if (type != NID_sm3 || dgstlen != 32)
366 SM2err(SM2_F_SM2_SIGN, SM2_R_INVALID_DIGEST_TYPE);
370 e = BN_bin2bn(dgst, dgstlen, NULL);
372 s = SM2_sig_gen(eckey, e);
374 *siglen = i2d_ECDSA_SIG(s, &sig);
384 int SM2_verify(int type, const unsigned char *dgst, int dgstlen,
385 const unsigned char *sig, int sig_len, EC_KEY *eckey)
389 const unsigned char *p = sig;
390 unsigned char *der = NULL;
396 SM2err(SM2_F_SM2_VERIFY, SM2_R_INVALID_DIGEST_TYPE);
403 SM2err(SM2_F_SM2_VERIFY, ERR_R_MALLOC_FAILURE);
406 if (d2i_ECDSA_SIG(&s, &p, sig_len) == NULL)
408 SM2err(SM2_F_SM2_VERIFY, SM2_R_INVALID_ENCODING);
411 /* Ensure signature uses DER and doesn't have trailing garbage */
412 derlen = i2d_ECDSA_SIG(s, &der);
413 if (derlen != sig_len || memcmp(sig, der, derlen) != 0)
415 SM2err(SM2_F_SM2_VERIFY, SM2_R_INVALID_ENCODING);
419 e = BN_bin2bn(dgst, dgstlen, NULL);
421 ret = SM2_sig_verify(eckey, s, e);