-
Notifications
You must be signed in to change notification settings - Fork 10
/
sm2.c
1076 lines (987 loc) · 30.8 KB
/
sm2.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/* sm2.c
*
* Copyright (C) 2006-2024 wolfSSL Inc.
*
* This file is part of wolfSSL.
*
* wolfSSL is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* wolfSSL is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
*/
/* Based on 'SM2 Digital Signature Algorithm draft-shen-sm2-ecdsa-02'
* https://datatracker.ietf.org/doc/html/draft-shen-sm2-ecdsa-02
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <wolfssl/wolfcrypt/settings.h>
#if defined(WOLFSSL_SM2) && defined(HAVE_ECC)
#include <wolfssl/wolfcrypt/sm2.h>
#include <wolfssl/wolfcrypt/sp.h>
#include <wolfssl/wolfcrypt/error-crypt.h>
#include <wolfssl/wolfcrypt/hash.h>
#include <wolfssl/wolfcrypt/coding.h>
#include <wolfssl/wolfcrypt/asn.h>
#include <wolfssl/wolfcrypt/logging.h>
#include <wolfssl/wolfcrypt/logging.h>
#ifdef NO_INLINE
#include <wolfssl/wolfcrypt/misc.h>
#else
#define WOLFSSL_MISC_INCLUDED
#include <wolfcrypt/src/misc.c>
#endif
/* Maximum number of signature generations to attempt before giving up. */
#define ECC_SM2_MAX_SIG_GEN 64
#ifndef NO_HASH_WRAPPER
/* Convert hex string to binary and hash it.
*
* @param [in] hash Hash algorithm object.
* @param [in] hashType Type of hash to perform.
* @param [in] hexIn Hexadecimal string.
* @param [in] hexSz Number of characters to hash.
* @param [in] tmp Buffer to encode into.
* @return 0 on success
* @return MEMORY_E on dynamic memory allocation failure.
*/
static int ecc_sm2_digest_hashin(wc_HashAlg* hash, enum wc_HashType hashType,
const char* hexIn, int hexSz, byte* tmp)
{
int err = 0;
word32 tmpSz;
/* Number of bytes in binary as type word32. */
tmpSz = (word32)hexSz;
if (err == 0) {
/* Convert hexadecimal string to binary. */
err = Base16_Decode((const byte*)hexIn, tmpSz, tmp, &tmpSz);
}
if (err == 0) {
/* Update the hash with the binary data. */
err = wc_HashUpdate(hash, hashType, tmp, tmpSz);
}
return err;
}
/* Calculate ZA with hash type specified for sign/verify.
*
* 5.1.4.4:
* ZA=H256(ENTLA || IDA || a || b || xG || yG || xA || yA)
*
* @param [in] id ID of A to be hashed.
* @param [in] idSz Size of ID of A in bytes.
* @param [in] hash Hash algorithm object.
* @param [in] hashType Hash type to use.
* @param [in] key SM2 ECC key that has already been setup.
* @param [out] out Buffer to hold final digest.
* @return 0 on success.
* @return Negative on failure.
*/
static int _ecc_sm2_calc_za(const byte *id, word16 idSz,
wc_HashAlg* hash, enum wc_HashType hashType, ecc_key* key, byte* out)
{
int err = 0;
byte entla[2]; /* RFC draft states ID size is always encoded in 2 bytes. */
word16 sz = 0;
#ifdef WOLFSSL_SMALL_STACK
byte* xA = NULL;
byte* yA = NULL;
#else
/* Modify if more than one SM2 curve. */
byte xA[33];
byte yA[33];
#endif
word32 xASz;
word32 yASz;
/* Get ID of A size in bits. */
sz = idSz * WOLFSSL_BIT_SIZE;
/* Set big-endian 16-bit word. */
entla[0] = (byte)(sz >> WOLFSSL_BIT_SIZE);
entla[1] = (byte)(sz & 0xFF);
#ifdef DEBUG_ECC_SM2
WOLFSSL_MSG("ENTLA");
WOLFSSL_BUFFER(entla, 2);
#endif
/* Get ordinate size. */
xASz = yASz = (word32)wc_ecc_size(key);
#ifdef WOLFSSL_SMALL_STACK
/* Allocate memory for the x-ordinate. */
xA = (byte*)XMALLOC(xASz + 1, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
if (xA == NULL) {
err = MEMORY_E;
}
if (err == 0) {
/* Allocate memory for the y-ordinate. */
yA = (byte*)XMALLOC(yASz + 1, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
if (yA == NULL) {
err = MEMORY_E;
}
}
#endif
if (err == 0) {
/* Hash the ENTLA - length of ID of A. */
err = wc_HashUpdate(hash, hashType, (byte*)&entla, 2);
}
if (err == 0) {
/* Hash the ID of A. */
err = wc_HashUpdate(hash, hashType, id, idSz);
}
if (err == 0) {
/* Hash the a coefficient of the curve. */
err = ecc_sm2_digest_hashin(hash, hashType, key->dp->Af,
(int)XSTRLEN(key->dp->Af), xA);
}
if (err == 0) {
/* Hash the b coefficient of the curve. */
err = ecc_sm2_digest_hashin(hash, hashType, key->dp->Bf,
(int)XSTRLEN(key->dp->Bf), xA);
}
if (err == 0) {
/* Hash the x-ordinate of the base point. */
err = ecc_sm2_digest_hashin(hash, hashType, key->dp->Gx,
(int)XSTRLEN(key->dp->Gx), xA);
}
if (err == 0) {
/* Hash the y-ordinate of the base point. */
err = ecc_sm2_digest_hashin(hash, hashType, key->dp->Gy,
(int)XSTRLEN(key->dp->Gy), xA);
}
if (err == 0) {
/* Get the x and y ordinates. */
err = wc_ecc_export_public_raw(key, xA, &xASz, yA, &yASz);
}
if (err == 0) {
/* Hash the x-ordinate of the public key. */
err = wc_HashUpdate(hash, hashType, xA, xASz);
}
#ifdef WOLFSSL_SMALL_STACK
XFREE(xA, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
#endif
if (err == 0) {
/* Hash the y-ordinate of the public key. */
err = wc_HashUpdate(hash, hashType, yA, yASz);
}
#ifdef WOLFSSL_SMALL_STACK
XFREE(yA, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
#endif
if (err == 0) {
/* Output the hash - ZA. */
err = wc_HashFinal(hash, hashType, out);
}
#ifdef DEBUG_ECC_SM2
if (err == 0) {
WOLFSSL_MSG("ZA");
WOLFSSL_BUFFER(out, wc_HashGetDigestSize(hashType));
}
#endif
return err;
}
/* Calculate SM2 hash of the type specified for sign/verify.
*
* 5.2.1, A2:
* Hash Out = Hash(ZA || M)
*
* @param [in] za ZA to be hashed.
* @param [in] zaSz Size of ZA in bytes.
* @param [in] msg Message to be signed.
* @param [in] msgSz Size of message in bytes.
* @param [in] hash Hash algorithm object.
* @param [in] hashType Hash type to use.
* @param [out] out Buffer to hold final digest.
* @return 0 on success.
* @return Negative on failure.
*/
static int _ecc_sm2_calc_msg_hash(const byte* za, int zaSz, const byte* msg,
int msgSz, wc_HashAlg* hash, enum wc_HashType hashType, byte* out)
{
int err;
/* Initialize the hash for new operation. */
err = wc_HashInit_ex(hash, hashType, NULL, 0);
if (err == 0) {
/* Hash ZA. */
err = wc_HashUpdate(hash, hashType, za, (word32)zaSz);
}
if (err == 0) {
/* Hash the message. */
err = wc_HashUpdate(hash, hashType, msg, (word32)msgSz);
}
if (err == 0) {
/* Output the hash. */
err = wc_HashFinal(hash, hashType, out);
}
#ifdef DEBUG_ECC_SM2
if (err == 0) {
WOLFSSL_MSG("Hv(ZA || M)");
WOLFSSL_BUFFER(out, wc_HashGetDigestSize(hashType));
}
#endif
return err;
}
/* Create SM2 hash of the type specified for sign/verify.
*
* 5.1.4.4:
* ZA=H256(ENTLA || IDA || a || b || xG || yG || xA || yA)
* 5.2.1:
* A1: M~=ZA || M
* A2: e=Hv(M~)
*
* @param [in] id ID of A to be hashed.
* @param [in] idSz Size of ID of A in bytes.
* @param [in] msg Message to be signed.
* @param [in] msgSz Size of message in bytes.
* @param [in] hashType Hash type to use.
* @param [out] out Buffer to hold final digest.
* @param [in] outSz Size of output buffer in bytes.
* @param [in] key SM2 ECC key that has already been setup.
* @return 0 on success.
* @return BAD_FUNC_ARG when key, out, msg or id is NULL.
* @return BAD_FUNC_ARG when hash type is not supported.
* @return BUFFER_E when hash size is larger than output size.
* @return MEMORY_E on dynamic memory allocation failure.
*/
int wc_ecc_sm2_create_digest(const byte *id, word16 idSz,
const byte* msg, int msgSz, enum wc_HashType hashType, byte* out, int outSz,
ecc_key* key)
{
int err = 0;
int hashSz = 0;
#ifdef WOLFSSL_SMALL_STACK
wc_HashAlg* hash = NULL;
#else
wc_HashAlg hash[1];
#endif
int hash_inited = 0;
/* Validate parameters. */
if ((key == NULL) || (key->dp == NULL) || (out == NULL) || (msg == NULL) ||
(id == NULL)) {
err = BAD_FUNC_ARG;
}
/* Get hash size. */
if ((err == 0) && ((hashSz = wc_HashGetDigestSize(hashType)) < 0)) {
err = BAD_FUNC_ARG;
}
/* Check hash size fits in output. */
if ((err == 0) && (hashSz > outSz)) {
err = BUFFER_E;
}
#ifdef WOLFSSL_SMALL_STACK
if (err == 0) {
hash = (wc_HashAlg*)XMALLOC(sizeof(wc_HashAlg), key->heap,
DYNAMIC_TYPE_HASHES);
if (hash == NULL) {
err = MEMORY_E;
}
}
#endif
if (err == 0) {
/* Initialize hash algorithm object. */
err = wc_HashInit_ex(hash, hashType, key->heap, 0);
}
if (err == 0) {
hash_inited = 1;
}
/* Calculate ZA. */
if (err == 0) {
err = _ecc_sm2_calc_za(id, idSz, hash, hashType, key, out);
}
/* Calculate message hash. */
if (err == 0) {
err = _ecc_sm2_calc_msg_hash(out, hashSz, msg, msgSz, hash, hashType,
out);
}
/* Dispose of allocated data. */
if (hash_inited) {
(void)wc_HashFree(hash, hashType);
}
#ifdef WOLFSSL_SMALL_STACK
XFREE(hash, key->heap, DYNAMIC_TYPE_HASHES);
#endif
return err;
}
#endif /* NO_HASH_WRAPPER */
/* Make a key on the SM2 curve.
*
* @param [in] rng Random number generator.
* @param [out] key ECC key to hold generated key.
* @param [in] flags Flags to set against ECC key.
* @return 0 on success.
*/
int wc_ecc_sm2_make_key(WC_RNG* rng, ecc_key* key, int flags)
{
return wc_ecc_make_key_ex2(rng, 32, key, ECC_SM2P256V1, flags);
}
/* Create a shared secret from the private key and peer's public key.
*
* @param [in] priv Private key.
* @param [in] pub Peer's public key.
* @param [out] out Array containing secret.
* @param [in, out] outLen On in, length of array in bytes.
* On out, number of bytes in secret.
*/
int wc_ecc_sm2_shared_secret(ecc_key* priv, ecc_key* pub, byte* out,
word32* outLen)
{
return wc_ecc_shared_secret(priv, pub, out, outLen);
}
#ifdef HAVE_ECC_SIGN
#ifndef WOLFSSL_SP_MATH
/* Calculate r and s of signature.
*
* @param [in] x Private key.
* @param [in] px Ephemeral point's x-ordinate.
* @param [in] k Ephemeral private key.
* @param [in] e Hash of message.
* @param [in] order Order of curve.
* @param [in] b Blinding value.
* @param [out] r 'r' value of signature.
* @param [out] s 's' value of signature.
* @return MP_OKAY on success.
* @return MP_MEM when dynamic memory allocation fails.
*/
static int _ecc_sm2_calc_r_s(mp_int* x, mp_int* px, mp_int* k, mp_int* e,
mp_int* order, mp_int* b, mp_int* r, mp_int* s)
{
int err;
/* r = p->x + e */
err = mp_addmod_ct(px, e, order, r);
/* Check r != 0 */
if ((err == MP_OKAY) && mp_iszero(r)) {
err = MP_ZERO_E;
}
/* Calc r + k */
if (err == MP_OKAY) {
err = mp_addmod_ct(r, k, order, s);
}
/* Check r + k != 0 */
if ((err == MP_OKAY) && mp_iszero(s)) {
err = MP_ZERO_E;
}
/* s = x.r */
if (err == MP_OKAY) {
err = mp_mulmod(r, x, order, s);
}
/* x' = x + 1 */
if (err == MP_OKAY) {
err = mp_add_d(x, 1, x);
}
/* x'' = x'.b = (x+1).b */
if (err == MP_OKAY) {
err = mp_mulmod(x, b, order, x);
}
/* x''' = 1/x'' = 1/((x+1).b) */
if (err == MP_OKAY) {
err = mp_invmod(x, order, x);
}
/* k' = k * x''' = k / ((x+1).b) */
if (err == MP_OKAY) {
err = mp_mulmod(k, x, order, k);
}
/* s' = s * x''' = x.r / ((x+1).b) */
if (err == MP_OKAY) {
err = mp_mulmod(s, x, order, s);
}
/* s'' = k' - s' = (k - x.r) / ((x+1).b) */
if (err == MP_OKAY) {
err = mp_submod_ct(k, s, order, s);
}
/* s''' = s'' * b = (k - x.r) / (x+1) */
if (err == MP_OKAY) {
err = mp_mulmod(s, b, order, s);
}
return err;
}
#endif
/* Calculate the signature from the hash with a key on the SM2 curve.
*
* Use wc_ecc_sm2_create_digest to calculate the digest.
*
* @param [in] hash Array of bytes holding hash value.
* @param [in] hashSz Size of hash in bytes.
* @param [in] rng Random number generator.
* @param [in] key ECC private key.
* @param [out] r 'r' part of signature as an MP integer.
* @param [out] s 's' part of signature as an MP integer.
* @return MP_OKAY on success.
* @return ECC_BAD_ARGE_E when hash, r, s, key or rng is NULL.
* @return ECC_BAD_ARGE_E when key is not on SM2 curve.
*/
int wc_ecc_sm2_sign_hash_ex(const byte* hash, word32 hashSz, WC_RNG* rng,
ecc_key* key, mp_int* r, mp_int* s)
{
int err = MP_OKAY;
#ifndef WOLFSSL_SP_MATH
mp_int* x = NULL;
mp_int* e = NULL;
mp_int* b = NULL;
mp_int* order = NULL;
#ifdef WOLFSSL_SMALL_STACK
ecc_key* pub = NULL;
mp_int* data = NULL;
#else
ecc_key pub[1];
mp_int data[4];
#endif
int i;
#endif
/* Validate parameters. */
if ((hash == NULL) || (r == NULL) || (s == NULL) || (key == NULL) ||
(key->dp == NULL) || (rng == NULL)) {
err = BAD_FUNC_ARG;
}
/* SM2 signature must be with a key on the SM2 curve. */
if ((err == MP_OKAY) && (key->dp->id != ECC_SM2P256V1) &&
(key->idx != ECC_CUSTOM_IDX)) {
err = BAD_FUNC_ARG;
}
#if defined(WOLFSSL_HAVE_SP_ECC) && defined(WOLFSSL_SP_SM2)
if ((err == MP_OKAY) && (key->dp->id == ECC_SM2P256V1)) {
/* Use optimized code in SP to perform signing. */
SAVE_VECTOR_REGISTERS(return _svr_ret;);
err = sp_ecc_sign_sm2_256(hash, hashSz, rng, key->k, r, s, NULL,
key->heap);
RESTORE_VECTOR_REGISTERS();
return err;
}
#endif
#ifndef WOLFSSL_SP_MATH
#ifdef WOLFSSL_SMALL_STACK
if (err == MP_OKAY) {
/* Allocate ECC key. */
pub = (ecc_key*)XMALLOC(sizeof(ecc_key), key->heap, DYNAMIC_TYPE_ECC);
if (pub == NULL) {
err = MEMORY_E;
}
}
if (err == MP_OKAY) {
/* Allocate MP integers. */
data = (mp_int*)XMALLOC(sizeof(mp_int) * 4, key->heap,
DYNAMIC_TYPE_ECC);
if (data == NULL) {
err = MEMORY_E;
}
}
#endif
if (err == MP_OKAY) {
x = data;
e = data + 1;
b = data + 2;
order = data + 3;
}
/* Initialize MP integers needed. */
if (err == MP_OKAY) {
err = mp_init_multi(x, e, b, order, NULL, NULL);
}
if (err == MP_OKAY) {
/* Initialize ephemeral key. */
err = wc_ecc_init_ex(pub, key->heap, INVALID_DEVID);
if (err == MP_OKAY) {
/* Load the order into an MP integer for generating blinding value.
*/
err = mp_read_radix(order, key->dp->order, MP_RADIX_HEX);
}
if (err == MP_OKAY) {
/* Convert hash to a number. */
err = mp_read_unsigned_bin(e, hash, hashSz);
}
if (err == MP_OKAY) {
/* Reduce the hash value to that of the order once. */
err = mp_mod(e, order, e);
}
if (err == MP_OKAY) {
do {
/* Generate blinding value. */
err = wc_ecc_gen_k(rng, 32, b, order);
}
while (err == MP_ZERO_E);
/* Try generating a signature a number of times. */
for (i = 0; (err == MP_OKAY) && (i < ECC_SM2_MAX_SIG_GEN); i++) {
/* Make a new ephemeral key. */
err = wc_ecc_sm2_make_key(rng, pub, WC_ECC_FLAG_NONE);
if (err == MP_OKAY) {
/* Copy the private key into temporary. */
err = mp_copy(wc_ecc_key_get_priv(key), x);
}
if (err == MP_OKAY) {
/* Calculate R and S. */
err = _ecc_sm2_calc_r_s(x, pub->pubkey.x,
wc_ecc_key_get_priv(pub), e, order, b, r, s);
}
/* Done if it worked. */
if (err == MP_OKAY) {
break;
}
/* Try again if random values not usable. */
if (err == MP_ZERO_E) {
err = MP_OKAY;
}
}
/* Dispose of emphemeral key. */
wc_ecc_free(pub);
}
/* Dispose of temproraries - x and b are sensitive data. */
mp_forcezero(x);
mp_forcezero(b);
mp_free(e);
mp_free(order);
}
#ifdef WOLFSSL_SMALL_STACK
XFREE(pub, key->heap, DYNAMIC_TYPE_ECC);
XFREE(data, key->heap, DYNAMIC_TYPE_ECC);
#endif
#else
(void)hashSz;
err = NOT_COMPILED_IN;
#endif
return err;
}
/* Calculate the signature from the hash with a key on the SM2 curve.
*
* Use wc_ecc_sm2_create_digest to calculate the digest.
*
* @param [in] hash Array of bytes holding hash value.
* @param [in] hashSz Size of hash in bytes.
* @param [in] rng Random number generator.
* @param [in] key ECC private key.
* @param [out] sig DER encoded DSA signature.
* @param [out] sigSz On in, size of signature buffer in bytes.
* On out, length of signature in bytes.
* @return MP_OKAY on success.
* @return ECC_BAD_ARGE_E when hash, r, s, key or rng is NULL.
* @return ECC_BAD_ARGE_E when key is not on SM2 curve.
*/
int wc_ecc_sm2_sign_hash(const byte* hash, word32 hashSz, byte* sig,
word32 *sigSz, WC_RNG* rng, ecc_key* key)
{
int err = MP_OKAY;
#if !defined(WOLFSSL_ASYNC_CRYPT) || !defined(WC_ASYNC_ENABLE_ECC)
#ifdef WOLFSSL_SMALL_STACK
mp_int *r = NULL, *s = NULL;
#else
mp_int r[1], s[1];
#endif
#endif
/* Validate parameters. */
if ((hash == NULL) || (sig == NULL) || (sigSz == NULL) || (key == NULL) ||
(key->dp == NULL) || (rng == NULL)) {
err = BAD_FUNC_ARG;
}
/* SM2 signature must be with a key on the SM2 curve. */
if ((err == MP_OKAY) && (key->dp->id != ECC_SM2P256V1) &&
(key->idx != ECC_CUSTOM_IDX)) {
err = BAD_FUNC_ARG;
}
#ifdef WOLFSSL_SMALL_STACK
if (err == MP_OKAY) {
/* Allocate MP integers. */
r = (mp_int*)XMALLOC(sizeof(mp_int), key->heap, DYNAMIC_TYPE_ECC);
if (r == NULL)
err = MEMORY_E;
}
if (err == MP_OKAY) {
s = (mp_int*)XMALLOC(sizeof(mp_int), key->heap, DYNAMIC_TYPE_ECC);
if (s == NULL) {
err = MEMORY_E;
}
}
#endif
/* Clear out MP integers. */
#ifdef WOLFSSL_SMALL_STACK
if (r != NULL)
#endif
XMEMSET(r, 0, sizeof(mp_int));
#ifdef WOLFSSL_SMALL_STACK
if (s != NULL)
#endif
XMEMSET(s, 0, sizeof(mp_int));
/* Initialize MP integers. */
if (err == MP_OKAY)
err = mp_init_multi(r, s, NULL, NULL, NULL, NULL);
/* Generate signature into numbers. */
if (err == MP_OKAY)
err = wc_ecc_sm2_sign_hash_ex(hash, hashSz, rng, key, r, s);
/* Encode r and s in DER DSA signature format. */
if (err == MP_OKAY)
err = StoreECC_DSA_Sig(sig, sigSz, r, s);
/* Dispose of temporaries. */
mp_clear(r);
mp_clear(s);
#ifdef WOLFSSL_SMALL_STACK
/* Free allocated data. */
XFREE(s, key->heap, DYNAMIC_TYPE_ECC);
XFREE(r, key->heap, DYNAMIC_TYPE_ECC);
#endif
return err;
}
#endif
#ifdef HAVE_ECC_VERIFY
#ifndef WOLFSSL_SP_MATH
/* Scalar multiply two scalars against respective points and add result.
*
* @param [in] mG First point to multiply.
* @param [in] u1 First scalar.
* @param [in] mQ Second point to multiply.
* @param [in] u2 Second scalar.
* @param [out] mR Point to store result in.
* @param [in] a Coefficient a of the curve.
* @param [in] modulus Modulus of curve.
* @param [in] heap Dynamic memory allocation hint.
* @return MP_OKAY on success.
* @return MP_VAL when a parameter is invalid.
* @return MP_MEM when dynamic memory allocation fails.
*/
static int ecc_sm2_mul2add(ecc_point* mG, mp_int* u1, ecc_point* mQ, mp_int* u2,
ecc_point* mR, mp_int* a, mp_int* modulus, void* heap)
{
int err;
#ifndef ECC_SHAMIR
mp_digit mp = 0;
/* Calculate the Montgomery multiplier. */
err = mp_montgomery_setup(modulus, &mp);
if ((err == 0) && (!mp_iszero(u1))) {
/* Compute mR = u1 * mG + u2 * mQ */
/* mG = u1 * mG */
err = wc_ecc_mulmod_ex(u1, mG, mG, a, modulus, 0, heap);
if (err == MP_OKAY) {
/* mQ = u2 * mQ */
err = wc_ecc_mulmod_ex(u2, mQ, mR, a, modulus, 0, heap);
}
if (err == MP_OKAY) {
/* mR = mQ + mG */
err = ecc_projective_add_point(mR, mG, mR, a, modulus, mp);
}
if (err == MP_OKAY && mp_iszero(mR->z)) {
/* When all zero then should have done a double instead. */
if (mp_iszero(mR->x) && mp_iszero(mR->y)) {
/* mR = mQ * 2 (mG = mQ) */
err = ecc_projective_dbl_point(mQ, mR, a, modulus, mp);
}
else {
/* When only Z zero then result is infinity. */
err = mp_set(mR->x, 0);
if (err == MP_OKAY)
err = mp_set(mR->y, 0);
if (err == MP_OKAY)
err = mp_set(mR->z, 1);
}
}
}
else if (err == 0) {
/* Compute mR = 0 * mG + u2 * mQ => mR = u2 * mQ */
err = wc_ecc_mulmod_ex(u2, mQ, mR, a, modulus, 0, heap);
}
/* Convert from Jacobian to affine. */
if (err == MP_OKAY) {
err = ecc_map(mR, modulus, mp);
}
#else
/* Use Shamir's trick to compute u1 * mG + u2 * mQ using half the doubles.
*/
err = ecc_mul2add(mG, u1, mQ, u2, mR, a, modulus, heap);
#endif /* ECC_SHAMIR */
return err;
}
#endif /* !WOLFSSL_SP_MATH */
/* Verify digest of hash(ZA || M) using key on SM2 curve and R and S.
*
* res gets set to 1 on successful verify and 0 on failure
*
* Use wc_ecc_sm2_create_digest to calculate the digest.
*
* @param [in] r MP integer holding r part of signature.
* @param [in] s MP integer holding s part of signature.
* @param [in] hash Array of bytes holding hash value.
* @param [in] hashSz Size of hash in bytes.
* @param [out] res 1 on successful verify and 0 on failure.
* @param [in] key Public key on SM2 curve.
* @return 0 on success (note this is even when successfully finding verify is
* incorrect)
* @return BAD_FUNC_ARG when key, res, r, s or hash is NULL.
* @return MP_VAL when r + s = 0.
* @return MEMORY_E on dynamic memory allocation failure.
* @return MP_MEM when dynamic memory allocation fails.
*/
int wc_ecc_sm2_verify_hash_ex(mp_int *r, mp_int *s, const byte *hash,
word32 hashSz, int *res, ecc_key *key)
{
int err = MP_OKAY;
#ifndef WOLFSSL_SP_MATH
ecc_point* PO = NULL;
ecc_point* G = NULL;
mp_int* t = NULL;
mp_int* e = NULL;
mp_int* prime = NULL;
mp_int* Af = NULL;
mp_int* order = NULL;
#ifdef WOLFSSL_SMALL_STACK
mp_int* data = NULL;
#else
mp_int data[5];
#endif
#endif
/* Validate parameters. */
if ((key == NULL) || (key->dp == NULL) || (res == NULL) || (r == NULL) ||
(s == NULL) || (hash == NULL)) {
err = BAD_FUNC_ARG;
}
/* SM2 signature must be with a key on the SM2 curve. */
if ((err == MP_OKAY) && (key->dp->id != ECC_SM2P256V1) &&
(key->idx != ECC_CUSTOM_IDX)) {
err = BAD_FUNC_ARG;
}
#if defined(WOLFSSL_HAVE_SP_ECC) && defined(WOLFSSL_SP_SM2)
if ((err == MP_OKAY) && (key->dp->id == ECC_SM2P256V1)) {
/* Use optimized code in SP to perform verification. */
SAVE_VECTOR_REGISTERS(return _svr_ret;);
err = sp_ecc_verify_sm2_256(hash, hashSz, key->pubkey.x,
key->pubkey.y, key->pubkey.z, r, s, res, key->heap);
RESTORE_VECTOR_REGISTERS();
return err;
}
#endif
#ifndef WOLFSSL_SP_MATH
if (res != NULL) {
/* Assume failure. */
*res = 0;
}
#ifdef WOLFSSL_SMALL_STACK
if (err == MP_OKAY) {
/* Allocate temporary MP integer. */
data = (mp_int*)XMALLOC(sizeof(mp_int) * 5, key->heap,
DYNAMIC_TYPE_ECC);
if (data == NULL) {
err = MEMORY_E;
}
}
#endif
if (err == MP_OKAY) {
t = data;
e = data + 1;
prime = data + 2;
Af = data + 3;
order = data + 4;
}
if (err == MP_OKAY) {
/* Initialize temporary MP integers. */
err = mp_init_multi(e, t, prime, Af, order, NULL);
}
if (err == MP_OKAY) {
/* Get order. */
err = mp_read_radix(order, key->dp->order, MP_RADIX_HEX);
}
/* B5: calculate t = (r' + s') modn -- if t is 0 then failed */
if (err == MP_OKAY) {
/* t = r + s */
err = mp_addmod(r, s, order, t);
}
if (err == MP_OKAY) {
/* Check sum is valid. */
if (mp_iszero(t) == MP_YES)
err = MP_VAL;
}
#ifdef DEBUG_ECC_SM2
mp_dump("t = ", t, 0);
#endif
/* B6: calculate the point (x1', y1')=[s']G + [t]PA */
if (err == MP_OKAY) {
/* Create two new points. */
PO = wc_ecc_new_point_h(key->heap);
if (PO == NULL) {
err = MEMORY_E;
}
}
if (err == MP_OKAY) {
G = wc_ecc_new_point_h(key->heap);
if (G == NULL) {
err = MEMORY_E;
}
}
if (err == MP_OKAY) {
/* Get the base point x-ordinate for SM2 curve. */
err = mp_read_radix(G->x, key->dp->Gx, MP_RADIX_HEX);
}
if (err == MP_OKAY) {
/* Get the base point y-ordinate for SM2 curve. */
err = mp_read_radix(G->y, key->dp->Gy, MP_RADIX_HEX);
}
if (err == MP_OKAY) {
/* Base point is in affine so z-ordinate is one. */
err = mp_set(G->z, 1);
}
if (err == MP_OKAY) {
/* Get a coefficient of SM2 curve. */
err = mp_read_radix(Af, key->dp->Af, MP_RADIX_HEX);
}
if (err == MP_OKAY) {
/* Get a prime of SM2 curve. */
err = mp_read_radix(prime, key->dp->prime, MP_RADIX_HEX);
}
#ifdef DEBUG_ECC_SM2
printf("\n");
mp_dump("G->x = ", G->x, 0);
mp_dump("G->y = ", G->y, 0);
mp_dump("s = ", s, 0);
mp_dump("P->x = ", key->pubkey.x, 0);
mp_dump("P->y = ", key->pubkey.y, 0);
mp_dump("t = ", t, 0);
mp_dump("Af = ", Af, 0);
mp_dump("prime= ", prime, 0);
#endif
if (err == MP_OKAY) {
/* [s']G + [t]PA */
err = ecc_sm2_mul2add(G, s, &(key->pubkey), t, PO, Af, prime,
key->heap);
}
#ifdef DEBUG_ECC_SM2
mp_dump("PO->x = ", PO->x, 0);
mp_dump("PO->y = ", PO->y, 0);
printf("\n\n");
#endif
/* B7: calculate R=(e'+x1') modn, if R=r then passed */
if (err == MP_OKAY) {
/* Convert hash to an MP integer. */
err = mp_read_unsigned_bin(e, hash, hashSz);
}
if (err == MP_OKAY) {
/* e' + x1' */
err = mp_addmod(e, PO->x, order, t);
}
/* Calculated value must be same as r. */
if (err == MP_OKAY && mp_cmp(t, r) == MP_EQ) {
*res = 1;
}
/* Dispose of allocated points. */
if (PO != NULL) {
wc_ecc_del_point_h(PO, key->heap);
}
if (G != NULL) {
wc_ecc_del_point_h(G, key->heap);
}
/* Dispose of allocated MP integers. */
if (e != NULL) {
mp_free(e);
}
if (t != NULL) {
mp_free(t);
}
if (prime != NULL) {
mp_free(prime);
}
if (Af != NULL) {
mp_free(Af);
}
if (order != NULL) {
mp_free(order);
}
#ifdef WOLFSSL_SMALL_STACK
/* Free allocated data. */
XFREE(data, key->heap, DYNAMIC_TYPE_ECC);
#endif
#else
(void)hashSz;
err = NOT_COMPILED_IN;
#endif
return err;
}
#ifndef NO_ASN
/* Verify digest of hash(ZA || M) using key on SM2 curve and encoded signature.
*
* res gets set to 1 on successful verify and 0 on failure
*
* Use wc_ecc_sm2_create_digest to calculate the digest.
*
* @param [in] sig DER encoded DSA signature.
* @param [in] sigSz Length of signature in bytes.
* @param [in] hash Array of bytes holding hash value.
* @param [in] hashSz Size of hash in bytes.
* @param [out] res 1 on successful verify and 0 on failure.
* @param [in] key Public key on SM2 curve.
* @return 0 on success (note this is even when successfully finding verify is
* incorrect)
* @return BAD_FUNC_ARG when key, res, sig or hash is NULL.
* @return MP_VAL when r + s = 0.
* @return MEMORY_E on dynamic memory allocation failure.
* @return MP_MEM when dynamic memory allocation fails.
*/
int wc_ecc_sm2_verify_hash(const byte* sig, word32 sigSz, const byte* hash,
word32 hashSz, int* res, ecc_key* key)
{
int err = 0;
#ifdef WOLFSSL_SMALL_STACK
mp_int* r = NULL;
mp_int* s = NULL;