aboutsummaryrefslogtreecommitdiffstats
path: root/engines/e_sureware.c
blob: 8a23763f75d92064e4f66939bf0c8f74c5691909 (plain) (blame)
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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
/*-
*  Written by Corinne Dive-Reclus(cdive@baltimore.com)
*
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in
*    the documentation and/or other materials provided with the
*    distribution.
*
* 3. All advertising materials mentioning features or use of this
*    software must display the following acknowledgment:
*    "This product includes software developed by the OpenSSL Project
*    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
*    endorse or promote products derived from this software without
*    prior written permission. For written permission, please contact
*    licensing@OpenSSL.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
*    nor may "OpenSSL" appear in their names without prior written
*    permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
*    acknowledgment:
*    "This product includes software developed by the OpenSSL Project
*    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
*
* Written by Corinne Dive-Reclus(cdive@baltimore.com)
*
* Copyright@2001 Baltimore Technologies Ltd.
* All right Reserved.
*                                                                                      *
*        THIS FILE IS PROVIDED BY BALTIMORE TECHNOLOGIES ``AS IS'' AND                 *
*        ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE         *
*        IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE    *
*        ARE DISCLAIMED.  IN NO EVENT SHALL BALTIMORE TECHNOLOGIES BE LIABLE           *
*        FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL    *
*        DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS       *
*        OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)         *
*        HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT    *
*        LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY     *
*        OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF        *
*        SUCH DAMAGE.                                                                  *
====================================================================*/

#include <stdio.h>
#include <string.h>
#include <openssl/crypto.h>
#include <openssl/pem.h>
#include <openssl/dso.h>
#include <openssl/engine.h>
#include <openssl/rand.h>
#ifndef OPENSSL_NO_RSA
# include <openssl/rsa.h>
#endif
#ifndef OPENSSL_NO_DSA
# include <openssl/dsa.h>
#endif
#ifndef OPENSSL_NO_DH
# include <openssl/dh.h>
#endif
#include <openssl/bn.h>

#ifndef OPENSSL_NO_HW
# ifndef OPENSSL_NO_HW_SUREWARE

#  ifdef FLAT_INC
#   include "sureware.h"
#  else
#   include "vendor_defns/sureware.h"
#  endif

#  define SUREWARE_LIB_NAME "sureware engine"
#  include "e_sureware_err.c"

static int surewarehk_ctrl(ENGINE *e, int cmd, long i, void *p,
                           void (*f) (void));
static int surewarehk_destroy(ENGINE *e);
static int surewarehk_init(ENGINE *e);
static int surewarehk_finish(ENGINE *e);
static int surewarehk_modexp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
                             const BIGNUM *m, BN_CTX *ctx);

/* RSA stuff */
#  ifndef OPENSSL_NO_RSA
static int surewarehk_rsa_priv_dec(int flen, const unsigned char *from,
                                   unsigned char *to, RSA *rsa, int padding);
static int surewarehk_rsa_sign(int flen, const unsigned char *from,
                               unsigned char *to, RSA *rsa, int padding);
#  endif

/* RAND stuff */
static int surewarehk_rand_bytes(unsigned char *buf, int num);
static void surewarehk_rand_seed(const void *buf, int num);
static void surewarehk_rand_add(const void *buf, int num, double entropy);

/* KM stuff */
static EVP_PKEY *surewarehk_load_privkey(ENGINE *e, const char *key_id,
                                         UI_METHOD *ui_method,
                                         void *callback_data);
static EVP_PKEY *surewarehk_load_pubkey(ENGINE *e, const char *key_id,
                                        UI_METHOD *ui_method,
                                        void *callback_data);
static void surewarehk_ex_free(void *obj, void *item, CRYPTO_EX_DATA *ad,
                               int idx, long argl, void *argp);
#  if 0
static void surewarehk_dh_ex_free(void *obj, void *item, CRYPTO_EX_DATA *ad,
                                  int idx, long argl, void *argp);
#  endif

#  ifndef OPENSSL_NO_RSA
/* This function is aliased to mod_exp (with the mont stuff dropped). */
static int surewarehk_mod_exp_mont(BIGNUM *r, const BIGNUM *a,
                                   const BIGNUM *p, const BIGNUM *m,
                                   BN_CTX *ctx, BN_MONT_CTX *m_ctx)
{
    return surewarehk_modexp(r, a, p, m, ctx);
}

/* Our internal RSA_METHOD that we provide pointers to */
static RSA_METHOD surewarehk_rsa = {
    "SureWare RSA method",
    NULL,                       /* pub_enc */
    NULL,                       /* pub_dec */
    surewarehk_rsa_sign,        /* our rsa_sign is OpenSSL priv_enc */
    surewarehk_rsa_priv_dec,    /* priv_dec */
    NULL,                       /* mod_exp */
    surewarehk_mod_exp_mont,    /* mod_exp_mongomery */
    NULL,                       /* init */
    NULL,                       /* finish */
    0,                          /* RSA flag */
    NULL,
    NULL,                       /* OpenSSL sign */
    NULL,                       /* OpenSSL verify */
    NULL                        /* keygen */
};
#  endif

#  ifndef OPENSSL_NO_DH
/* Our internal DH_METHOD that we provide pointers to */
/* This function is aliased to mod_exp (with the dh and mont dropped). */
static int surewarehk_modexp_dh(const DH *dh, BIGNUM *r, const BIGNUM *a,
                                const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx,
                                BN_MONT_CTX *m_ctx)
{
    return surewarehk_modexp(r, a, p, m, ctx);
}

static DH_METHOD surewarehk_dh = {
    "SureWare DH method",
    NULL,                       /* gen_key */
    NULL,                       /* agree, */
    surewarehk_modexp_dh,       /* dh mod exp */
    NULL,                       /* init */
    NULL,                       /* finish */
    0,                          /* flags */
    NULL,
    NULL
};
#  endif

static RAND_METHOD surewarehk_rand = {
    /* "SureWare RAND method", */
    surewarehk_rand_seed,
    surewarehk_rand_bytes,
    NULL,                       /* cleanup */
    surewarehk_rand_add,
    surewarehk_rand_bytes,
    NULL,                       /* rand_status */
};

#  ifndef OPENSSL_NO_DSA
/* DSA stuff */
static DSA_SIG *surewarehk_dsa_do_sign(const unsigned char *dgst, int dlen,
                                       DSA *dsa);
static int surewarehk_dsa_mod_exp(DSA *dsa, BIGNUM *rr, BIGNUM *a1,
                                  BIGNUM *p1, BIGNUM *a2, BIGNUM *p2,
                                  BIGNUM *m, BN_CTX *ctx,
                                  BN_MONT_CTX *in_mont)
{
    BIGNUM t;
    int to_return = 0;
    BN_init(&t);
    /* let rr = a1 ^ p1 mod m */
    if (!surewarehk_modexp(rr, a1, p1, m, ctx))
        goto end;
    /* let t = a2 ^ p2 mod m */
    if (!surewarehk_modexp(&t, a2, p2, m, ctx))
        goto end;
    /* let rr = rr * t mod m */
    if (!BN_mod_mul(rr, rr, &t, m, ctx))
        goto end;
    to_return = 1;
 end:
    BN_free(&t);
    return to_return;
}

static DSA_METHOD surewarehk_dsa = {
    "SureWare DSA method",
    surewarehk_dsa_do_sign,
    NULL,                       /* sign setup */
    NULL,                       /* verify, */
    surewarehk_dsa_mod_exp,     /* mod exp */
    NULL,                       /* bn mod exp */
    NULL,                       /* init */
    NULL,                       /* finish */
    0,
    NULL,
    NULL,
    NULL
};
#  endif

static const char *engine_sureware_id = "sureware";
static const char *engine_sureware_name = "SureWare hardware engine support";

/* Now, to our own code */

/*
 * As this is only ever called once, there's no need for locking (indeed -
 * the lock will already be held by our caller!!!)
 */
static int bind_sureware(ENGINE *e)
{
#  ifndef OPENSSL_NO_RSA
    const RSA_METHOD *meth1;
#  endif
#  ifndef OPENSSL_NO_DSA
    const DSA_METHOD *meth2;
#  endif
#  ifndef OPENSSL_NO_DH
    const DH_METHOD *meth3;
#  endif

    if (!ENGINE_set_id(e, engine_sureware_id) ||
        !ENGINE_set_name(e, engine_sureware_name) ||
#  ifndef OPENSSL_NO_RSA
        !ENGINE_set_RSA(e, &surewarehk_rsa) ||
#  endif
#  ifndef OPENSSL_NO_DSA
        !ENGINE_set_DSA(e, &surewarehk_dsa) ||
#  endif
#  ifndef OPENSSL_NO_DH
        !ENGINE_set_DH(e, &surewarehk_dh) ||
#  endif
        !ENGINE_set_RAND(e, &surewarehk_rand) ||
        !ENGINE_set_destroy_function(e, surewarehk_destroy) ||
        !ENGINE_set_init_function(e, surewarehk_init) ||
        !ENGINE_set_finish_function(e, surewarehk_finish) ||
        !ENGINE_set_ctrl_function(e, surewarehk_ctrl) ||
        !ENGINE_set_load_privkey_function(e, surewarehk_load_privkey) ||
        !ENGINE_set_load_pubkey_function(e, surewarehk_load_pubkey))
        return 0;

#  ifndef OPENSSL_NO_RSA
    /*
     * We know that the "PKCS1_SSLeay()" functions hook properly to the
     * cswift-specific mod_exp and mod_exp_crt so we use those functions. NB:
     * We don't use ENGINE_openssl() or anything "more generic" because
     * something like the RSAref code may not hook properly, and if you own
     * one of these cards then you have the right to do RSA operations on it
     * anyway!
     */
    meth1 = RSA_PKCS1_SSLeay();
    if (meth1) {
        surewarehk_rsa.rsa_pub_enc = meth1->rsa_pub_enc;
        surewarehk_rsa.rsa_pub_dec = meth1->rsa_pub_dec;
    }
#  endif

#  ifndef OPENSSL_NO_DSA
    /*
     * Use the DSA_OpenSSL() method and just hook the mod_exp-ish bits.
     */
    meth2 = DSA_OpenSSL();
    if (meth2) {
        surewarehk_dsa.dsa_do_verify = meth2->dsa_do_verify;
    }
#  endif

#  ifndef OPENSSL_NO_DH
    /* Much the same for Diffie-Hellman */
    meth3 = DH_OpenSSL();
    if (meth3) {
        surewarehk_dh.generate_key = meth3->generate_key;
        surewarehk_dh.compute_key = meth3->compute_key;
    }
#  endif

    /* Ensure the sureware error handling is set up */
    ERR_load_SUREWARE_strings();
    return 1;
}

#  ifndef OPENSSL_NO_DYNAMIC_ENGINE
static int bind_helper(ENGINE *e, const char *id)
{
    if (id && (strcmp(id, engine_sureware_id) != 0))
        return 0;
    if (!bind_sureware(e))
        return 0;
    return 1;
}

IMPLEMENT_DYNAMIC_CHECK_FN()
    IMPLEMENT_DYNAMIC_BIND_FN(bind_helper)
#  else
static ENGINE *engine_sureware(void)
{
    ENGINE *ret = ENGINE_new();
    if (!ret)
        return NULL;
    if (!bind_sureware(ret)) {
        ENGINE_free(ret);
        return NULL;
    }
    return ret;
}

void ENGINE_load_sureware(void)
{
    /* Copied from eng_[openssl|dyn].c */
    ENGINE *toadd = engine_sureware();
    if (!toadd)
        return;
    ENGINE_add(toadd);
    ENGINE_free(toadd);
    ERR_clear_error();
}
#  endif

/*
 * This is a process-global DSO handle used for loading and unloading the
 * SureWareHook library. NB: This is only set (or unset) during an init() or
 * finish() call (reference counts permitting) and they're operating with
 * global locks, so this should be thread-safe implicitly.
 */
static DSO *surewarehk_dso = NULL;
#  ifndef OPENSSL_NO_RSA
/* Index for KM handle.  Not really used yet. */
static int rsaHndidx = -1;
#  endif
#  ifndef OPENSSL_NO_DSA
/* Index for KM handle.  Not really used yet. */
static int dsaHndidx = -1;
#  endif

/*
 * These are the function pointers that are (un)set when the library has
 * successfully (un)loaded.
 */
static SureWareHook_Init_t *p_surewarehk_Init = NULL;
static SureWareHook_Finish_t *p_surewarehk_Finish = NULL;
static SureWareHook_Rand_Bytes_t *p_surewarehk_Rand_Bytes = NULL;
static SureWareHook_Rand_Seed_t *p_surewarehk_Rand_Seed = NULL;
static SureWareHook_Load_Privkey_t *p_surewarehk_Load_Privkey = NULL;
static SureWareHook_Info_Pubkey_t *p_surewarehk_Info_Pubkey = NULL;
static SureWareHook_Load_Rsa_Pubkey_t *p_surewarehk_Load_Rsa_Pubkey = NULL;
static SureWareHook_Load_Dsa_Pubkey_t *p_surewarehk_Load_Dsa_Pubkey = NULL;
static SureWareHook_Free_t *p_surewarehk_Free = NULL;
static SureWareHook_Rsa_Priv_Dec_t *p_surewarehk_Rsa_Priv_Dec = NULL;
static SureWareHook_Rsa_Sign_t *p_surewarehk_Rsa_Sign = NULL;
static SureWareHook_Dsa_Sign_t *p_surewarehk_Dsa_Sign = NULL;
static SureWareHook_Mod_Exp_t *p_surewarehk_Mod_Exp = NULL;

/* Used in the DSO operations. */
static const char *surewarehk_LIBNAME = "SureWareHook";
static const char *n_surewarehk_Init = "SureWareHook_Init";
static const char *n_surewarehk_Finish = "SureWareHook_Finish";
static const char *n_surewarehk_Rand_Bytes = "SureWareHook_Rand_Bytes";
static const char *n_surewarehk_Rand_Seed = "SureWareHook_Rand_Seed";
static const char *n_surewarehk_Load_Privkey = "SureWareHook_Load_Privkey";
static const char *n_surewarehk_Info_Pubkey = "SureWareHook_Info_Pubkey";
static const char *n_surewarehk_Load_Rsa_Pubkey =
    "SureWareHook_Load_Rsa_Pubkey";
static const char *n_surewarehk_Load_Dsa_Pubkey =
    "SureWareHook_Load_Dsa_Pubkey";
static const char *n_surewarehk_Free = "SureWareHook_Free";
static const char *n_surewarehk_Rsa_Priv_Dec = "SureWareHook_Rsa_Priv_Dec";
static const char *n_surewarehk_Rsa_Sign = "SureWareHook_Rsa_Sign";
static const char *n_surewarehk_Dsa_Sign = "SureWareHook_Dsa_Sign";
static const char *n_surewarehk_Mod_Exp = "SureWareHook_Mod_Exp";
static BIO *logstream = NULL;

/*
 * SureWareHook library functions and mechanics - these are used by the
 * higher-level functions further down. NB: As and where there's no error
 * checking, take a look lower down where these functions are called, the
 * checking and error handling is probably down there.
 */
static int threadsafe = 1;
static int surewarehk_ctrl(ENGINE *e, int cmd, long i, void *p,
                           void (*f) (void))
{
    int to_return = 1;

    switch (cmd) {
    case ENGINE_CTRL_SET_LOGSTREAM:
        {
            BIO *bio = (BIO *)p;
            CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
            if (logstream) {
                BIO_free(logstream);
                logstream = NULL;
            }
            if (CRYPTO_add(&bio->references, 1, CRYPTO_LOCK_BIO) > 1)
                logstream = bio;
            else
                SUREWAREerr(SUREWARE_F_SUREWAREHK_CTRL,
                            SUREWARE_R_BIO_WAS_FREED);
        }
        CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
        break;
        /*
         * This will prevent the initialisation function from "installing"
         * the mutex-handling callbacks, even if they are available from
         * within the library (or were provided to the library from the
         * calling application). This is to remove any baggage for
         * applications not using multithreading.
         */
    case ENGINE_CTRL_CHIL_NO_LOCKING:
        CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
        threadsafe = 0;
        CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
        break;

        /* The command isn't understood by this engine */
    default:
        SUREWAREerr(SUREWARE_F_SUREWAREHK_CTRL,
                    ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED);
        to_return = 0;
        break;
    }

    return to_return;
}

/* Destructor (complements the "ENGINE_surewarehk()" constructor) */
static int surewarehk_destroy(ENGINE *e)
{
    ERR_unload_SUREWARE_strings();
    return 1;
}

/* (de)initialisation functions. */
static int surewarehk_init(ENGINE *e)
{
    char msg[64] = "ENGINE_init";
    SureWareHook_Init_t *p1 = NULL;
    SureWareHook_Finish_t *p2 = NULL;
    SureWareHook_Rand_Bytes_t *p3 = NULL;
    SureWareHook_Rand_Seed_t *p4 = NULL;
    SureWareHook_Load_Privkey_t *p5 = NULL;
    SureWareHook_Load_Rsa_Pubkey_t *p6 = NULL;
    SureWareHook_Free_t *p7 = NULL;
    SureWareHook_Rsa_Priv_Dec_t *p8 = NULL;
    SureWareHook_Rsa_Sign_t *p9 = NULL;
    SureWareHook_Dsa_Sign_t *p12 = NULL;
    SureWareHook_Info_Pubkey_t *p13 = NULL;
    SureWareHook_Load_Dsa_Pubkey_t *p14 = NULL;
    SureWareHook_Mod_Exp_t *p15 = NULL;

    if (surewarehk_dso != NULL) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_INIT, ENGINE_R_ALREADY_LOADED);
        goto err;
    }
    /* Attempt to load libsurewarehk.so/surewarehk.dll/whatever. */
    surewarehk_dso = DSO_load(NULL, surewarehk_LIBNAME, NULL, 0);
    if (surewarehk_dso == NULL) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_INIT, ENGINE_R_DSO_FAILURE);
        goto err;
    }
    if (!
        (p1 =
         (SureWareHook_Init_t *) DSO_bind_func(surewarehk_dso,
                                               n_surewarehk_Init))
|| !(p2 =
     (SureWareHook_Finish_t *) DSO_bind_func(surewarehk_dso,
                                             n_surewarehk_Finish))
|| !(p3 =
     (SureWareHook_Rand_Bytes_t *) DSO_bind_func(surewarehk_dso,
                                                 n_surewarehk_Rand_Bytes))
|| !(p4 =
     (SureWareHook_Rand_Seed_t *) DSO_bind_func(surewarehk_dso,
                                                n_surewarehk_Rand_Seed))
|| !(p5 =
     (SureWareHook_Load_Privkey_t *) DSO_bind_func(surewarehk_dso,
                                                   n_surewarehk_Load_Privkey))
|| !(p6 =
     (SureWareHook_Load_Rsa_Pubkey_t *) DSO_bind_func(surewarehk_dso,
                                                      n_surewarehk_Load_Rsa_Pubkey))
|| !(p7 =
     (SureWareHook_Free_t *) DSO_bind_func(surewarehk_dso, n_surewarehk_Free))
|| !(p8 =
     (SureWareHook_Rsa_Priv_Dec_t *) DSO_bind_func(surewarehk_dso,
                                                   n_surewarehk_Rsa_Priv_Dec))
|| !(p9 =
     (SureWareHook_Rsa_Sign_t *) DSO_bind_func(surewarehk_dso,
                                               n_surewarehk_Rsa_Sign))
|| !(p12 =
     (SureWareHook_Dsa_Sign_t *) DSO_bind_func(surewarehk_dso,
                                               n_surewarehk_Dsa_Sign))
|| !(p13 =
     (SureWareHook_Info_Pubkey_t *) DSO_bind_func(surewarehk_dso,
                                                  n_surewarehk_Info_Pubkey))
|| !(p14 =
     (SureWareHook_Load_Dsa_Pubkey_t *) DSO_bind_func(surewarehk_dso,
                                                      n_surewarehk_Load_Dsa_Pubkey))
|| !(p15 =
     (SureWareHook_Mod_Exp_t *) DSO_bind_func(surewarehk_dso,
                                              n_surewarehk_Mod_Exp))) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_INIT, ENGINE_R_DSO_FAILURE);
        goto err;
    }
    /* Copy the pointers */
    p_surewarehk_Init = p1;
    p_surewarehk_Finish = p2;
    p_surewarehk_Rand_Bytes = p3;
    p_surewarehk_Rand_Seed = p4;
    p_surewarehk_Load_Privkey = p5;
    p_surewarehk_Load_Rsa_Pubkey = p6;
    p_surewarehk_Free = p7;
    p_surewarehk_Rsa_Priv_Dec = p8;
    p_surewarehk_Rsa_Sign = p9;
    p_surewarehk_Dsa_Sign = p12;
    p_surewarehk_Info_Pubkey = p13;
    p_surewarehk_Load_Dsa_Pubkey = p14;
    p_surewarehk_Mod_Exp = p15;
    /* Contact the hardware and initialises it. */
    if (p_surewarehk_Init(msg, threadsafe) == SUREWAREHOOK_ERROR_UNIT_FAILURE) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_INIT, SUREWARE_R_UNIT_FAILURE);
        goto err;
    }
    if (p_surewarehk_Init(msg, threadsafe) == SUREWAREHOOK_ERROR_UNIT_FAILURE) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_INIT, SUREWARE_R_UNIT_FAILURE);
        goto err;
    }
    /*
     * try to load the default private key, if failed does not return a
     * failure but wait for an explicit ENGINE_load_privakey
     */
    surewarehk_load_privkey(e, NULL, NULL, NULL);

    /* Everything's fine. */
#  ifndef OPENSSL_NO_RSA
    if (rsaHndidx == -1)
        rsaHndidx = RSA_get_ex_new_index(0,
                                         "SureWareHook RSA key handle",
                                         NULL, NULL, surewarehk_ex_free);
#  endif
#  ifndef OPENSSL_NO_DSA
    if (dsaHndidx == -1)
        dsaHndidx = DSA_get_ex_new_index(0,
                                         "SureWareHook DSA key handle",
                                         NULL, NULL, surewarehk_ex_free);
#  endif

    return 1;
 err:
    if (surewarehk_dso)
        DSO_free(surewarehk_dso);
    surewarehk_dso = NULL;
    p_surewarehk_Init = NULL;
    p_surewarehk_Finish = NULL;
    p_surewarehk_Rand_Bytes = NULL;
    p_surewarehk_Rand_Seed = NULL;
    p_surewarehk_Load_Privkey = NULL;
    p_surewarehk_Load_Rsa_Pubkey = NULL;
    p_surewarehk_Free = NULL;
    p_surewarehk_Rsa_Priv_Dec = NULL;
    p_surewarehk_Rsa_Sign = NULL;
    p_surewarehk_Dsa_Sign = NULL;
    p_surewarehk_Info_Pubkey = NULL;
    p_surewarehk_Load_Dsa_Pubkey = NULL;
    p_surewarehk_Mod_Exp = NULL;
    return 0;
}

static int surewarehk_finish(ENGINE *e)
{
    int to_return = 1;
    if (surewarehk_dso == NULL) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_FINISH, ENGINE_R_NOT_LOADED);
        to_return = 0;
        goto err;
    }
    p_surewarehk_Finish();
    if (!DSO_free(surewarehk_dso)) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_FINISH, ENGINE_R_DSO_FAILURE);
        to_return = 0;
        goto err;
    }
 err:
    if (logstream)
        BIO_free(logstream);
    surewarehk_dso = NULL;
    p_surewarehk_Init = NULL;
    p_surewarehk_Finish = NULL;
    p_surewarehk_Rand_Bytes = NULL;
    p_surewarehk_Rand_Seed = NULL;
    p_surewarehk_Load_Privkey = NULL;
    p_surewarehk_Load_Rsa_Pubkey = NULL;
    p_surewarehk_Free = NULL;
    p_surewarehk_Rsa_Priv_Dec = NULL;
    p_surewarehk_Rsa_Sign = NULL;
    p_surewarehk_Dsa_Sign = NULL;
    p_surewarehk_Info_Pubkey = NULL;
    p_surewarehk_Load_Dsa_Pubkey = NULL;
    p_surewarehk_Mod_Exp = NULL;
    return to_return;
}

static void surewarehk_error_handling(char *const msg, int func, int ret)
{
    switch (ret) {
    case SUREWAREHOOK_ERROR_UNIT_FAILURE:
        ENGINEerr(func, SUREWARE_R_UNIT_FAILURE);
        break;
    case SUREWAREHOOK_ERROR_FALLBACK:
        ENGINEerr(func, SUREWARE_R_REQUEST_FALLBACK);
        break;
    case SUREWAREHOOK_ERROR_DATA_SIZE:
        ENGINEerr(func, SUREWARE_R_SIZE_TOO_LARGE_OR_TOO_SMALL);
        break;
    case SUREWAREHOOK_ERROR_INVALID_PAD:
        ENGINEerr(func, SUREWARE_R_PADDING_CHECK_FAILED);
        break;
    default:
        ENGINEerr(func, SUREWARE_R_REQUEST_FAILED);
        break;
    case 1:                    /* nothing */
        msg[0] = '\0';
    }
    if (*msg) {
        ERR_add_error_data(1, msg);
        if (logstream) {
            CRYPTO_w_lock(CRYPTO_LOCK_BIO);
            BIO_write(logstream, msg, strlen(msg));
            CRYPTO_w_unlock(CRYPTO_LOCK_BIO);
        }
    }
}

static int surewarehk_rand_bytes(unsigned char *buf, int num)
{
    int ret = 0;
    char msg[64] = "ENGINE_rand_bytes";
    if (!p_surewarehk_Rand_Bytes) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_RAND_BYTES,
                    ENGINE_R_NOT_INITIALISED);
    } else {
        ret = p_surewarehk_Rand_Bytes(msg, buf, num);
        surewarehk_error_handling(msg, SUREWARE_F_SUREWAREHK_RAND_BYTES, ret);
    }
    return ret == 1 ? 1 : 0;
}

static void surewarehk_rand_seed(const void *buf, int num)
{
    int ret = 0;
    char msg[64] = "ENGINE_rand_seed";
    if (!p_surewarehk_Rand_Seed) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_RAND_SEED,
                    ENGINE_R_NOT_INITIALISED);
    } else {
        ret = p_surewarehk_Rand_Seed(msg, buf, num);
        surewarehk_error_handling(msg, SUREWARE_F_SUREWAREHK_RAND_SEED, ret);
    }
}

static void surewarehk_rand_add(const void *buf, int num, double entropy)
{
    surewarehk_rand_seed(buf, num);
}

static EVP_PKEY *sureware_load_public(ENGINE *e, const char *key_id,
                                      char *hptr, unsigned long el,
                                      char keytype)
{
    EVP_PKEY *res = NULL;
#  ifndef OPENSSL_NO_RSA
    RSA *rsatmp = NULL;
#  endif
#  ifndef OPENSSL_NO_DSA
    DSA *dsatmp = NULL;
#  endif
    char msg[64] = "sureware_load_public";
    int ret = 0;
    if (!p_surewarehk_Load_Rsa_Pubkey || !p_surewarehk_Load_Dsa_Pubkey) {
        SUREWAREerr(SUREWARE_F_SUREWARE_LOAD_PUBLIC,
                    ENGINE_R_NOT_INITIALISED);
        goto err;
    }
    switch (keytype) {
#  ifndef OPENSSL_NO_RSA
    case 1:
         /*RSA*/
            /* set private external reference */
            rsatmp = RSA_new_method(e);
        RSA_set_ex_data(rsatmp, rsaHndidx, hptr);
        rsatmp->flags |= RSA_FLAG_EXT_PKEY;

        /* set public big nums */
        rsatmp->e = BN_new();
        rsatmp->n = BN_new();
        if(!rsatmp->e || !rsatmp->n)
            goto err;
        bn_expand2(rsatmp->e, el / sizeof(BN_ULONG));
        bn_expand2(rsatmp->n, el / sizeof(BN_ULONG));
        if (rsatmp->e->dmax != (int)(el / sizeof(BN_ULONG)) ||
            rsatmp->n->dmax != (int)(el / sizeof(BN_ULONG)))
            goto err;
        ret = p_surewarehk_Load_Rsa_Pubkey(msg, key_id, el,
                                           (unsigned long *)rsatmp->n->d,
                                           (unsigned long *)rsatmp->e->d);
        surewarehk_error_handling(msg, SUREWARE_F_SUREWARE_LOAD_PUBLIC, ret);
        if (ret != 1) {
            SUREWAREerr(SUREWARE_F_SUREWARE_LOAD_PUBLIC,
                        ENGINE_R_FAILED_LOADING_PUBLIC_KEY);
            goto err;
        }
        /* normalise pub e and pub n */
        rsatmp->e->top = el / sizeof(BN_ULONG);
        bn_fix_top(rsatmp->e);
        rsatmp->n->top = el / sizeof(BN_ULONG);
        bn_fix_top(rsatmp->n);
        /* create an EVP object: engine + rsa key */
        res = EVP_PKEY_new();
        EVP_PKEY_assign_RSA(res, rsatmp);
        break;
#  endif

#  ifndef OPENSSL_NO_DSA
    case 2:
         /*DSA*/
            /* set private/public external reference */
            dsatmp = DSA_new_method(e);
        DSA_set_ex_data(dsatmp, dsaHndidx, hptr);
        /*
         * dsatmp->flags |= DSA_FLAG_EXT_PKEY;
         */

        /* set public key */
        dsatmp->pub_key = BN_new();
        dsatmp->p = BN_new();
        dsatmp->q = BN_new();
        dsatmp->g = BN_new();
        if(!dsatmp->pub_key || !dsatmp->p || !dsatmp->q || !dsatmp->g)
            goto err;
        bn_expand2(dsatmp->pub_key, el / sizeof(BN_ULONG));
        bn_expand2(dsatmp->p, el / sizeof(BN_ULONG));
        bn_expand2(dsatmp->q, 20 / sizeof(BN_ULONG));
        bn_expand2(dsatmp->g, el / sizeof(BN_ULONG));
        if (dsatmp->pub_key->dmax != (int)(el / sizeof(BN_ULONG))
            || dsatmp->p->dmax != (int)(el / sizeof(BN_ULONG))
            || dsatmp->q->dmax != 20 / sizeof(BN_ULONG)
            || dsatmp->g->dmax != (int)(el / sizeof(BN_ULONG)))
            goto err;

        ret = p_surewarehk_Load_Dsa_Pubkey(msg, key_id, el,
                                           (unsigned long *)dsatmp->
                                           pub_key->d,
                                           (unsigned long *)dsatmp->p->d,
                                           (unsigned long *)dsatmp->q->d,
                                           (unsigned long *)dsatmp->g->d);
        surewarehk_error_handling(msg, SUREWARE_F_SUREWARE_LOAD_PUBLIC, ret);
        if (ret != 1) {
            SUREWAREerr(SUREWARE_F_SUREWARE_LOAD_PUBLIC,
                        ENGINE_R_FAILED_LOADING_PUBLIC_KEY);
            goto err;
        }
        /* set parameters */
        /* normalise pubkey and parameters in case of */
        dsatmp->pub_key->top = el / sizeof(BN_ULONG);
        bn_fix_top(dsatmp->pub_key);
        dsatmp->p->top = el / sizeof(BN_ULONG);
        bn_fix_top(dsatmp->p);
        dsatmp->q->top = 20 / sizeof(BN_ULONG);
        bn_fix_top(dsatmp->q);
        dsatmp->g->top = el / sizeof(BN_ULONG);
        bn_fix_top(dsatmp->g);

        /* create an EVP object: engine + rsa key */
        res = EVP_PKEY_new();
        EVP_PKEY_assign_DSA(res, dsatmp);
        break;
#  endif

    default:
        SUREWAREerr(SUREWARE_F_SUREWARE_LOAD_PUBLIC,
                    ENGINE_R_FAILED_LOADING_PRIVATE_KEY);
        goto err;
    }
    return res;
 err:
#  ifndef OPENSSL_NO_RSA
    if (rsatmp)
        RSA_free(rsatmp);
#  endif
#  ifndef OPENSSL_NO_DSA
    if (dsatmp)
        DSA_free(dsatmp);
#  endif
    return NULL;
}

static EVP_PKEY *surewarehk_load_privkey(ENGINE *e, const char *key_id,
                                         UI_METHOD *ui_method,
                                         void *callback_data)
{
    EVP_PKEY *res = NULL;
    int ret = 0;
    unsigned long el = 0;
    char *hptr = NULL;
    char keytype = 0;
    char msg[64] = "ENGINE_load_privkey";

    if (!p_surewarehk_Load_Privkey) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_LOAD_PRIVKEY,
                    ENGINE_R_NOT_INITIALISED);
    } else {
        ret = p_surewarehk_Load_Privkey(msg, key_id, &hptr, &el, &keytype);
        if (ret != 1) {
            SUREWAREerr(SUREWARE_F_SUREWAREHK_LOAD_PRIVKEY,
                        ENGINE_R_FAILED_LOADING_PRIVATE_KEY);
            ERR_add_error_data(1, msg);
        } else
            res = sureware_load_public(e, key_id, hptr, el, keytype);
    }
    return res;
}

static EVP_PKEY *surewarehk_load_pubkey(ENGINE *e, const char *key_id,
                                        UI_METHOD *ui_method,
                                        void *callback_data)
{
    EVP_PKEY *res = NULL;
    int ret = 0;
    unsigned long el = 0;
    char *hptr = NULL;
    char keytype = 0;
    char msg[64] = "ENGINE_load_pubkey";

    if (!p_surewarehk_Info_Pubkey) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_LOAD_PUBKEY,
                    ENGINE_R_NOT_INITIALISED);
    } else {
        /* call once to identify if DSA or RSA */
        ret = p_surewarehk_Info_Pubkey(msg, key_id, &el, &keytype);
        if (ret != 1) {
            SUREWAREerr(SUREWARE_F_SUREWAREHK_LOAD_PUBKEY,
                        ENGINE_R_FAILED_LOADING_PUBLIC_KEY);
            ERR_add_error_data(1, msg);
        } else
            res = sureware_load_public(e, key_id, hptr, el, keytype);
    }
    return res;
}

/*
 * This cleans up an RSA/DSA KM key(do not destroy the key into the hardware)
 * , called when ex_data is freed
 */
static void surewarehk_ex_free(void *obj, void *item, CRYPTO_EX_DATA *ad,
                               int idx, long argl, void *argp)
{
    if (!p_surewarehk_Free) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_EX_FREE, ENGINE_R_NOT_INITIALISED);
    } else
        p_surewarehk_Free((char *)item, 0);
}

#  if 0
/* not currently used (bug?) */
/*
 * This cleans up an DH KM key (destroys the key into hardware), called when
 * ex_data is freed
 */
static void surewarehk_dh_ex_free(void *obj, void *item, CRYPTO_EX_DATA *ad,
                                  int idx, long argl, void *argp)
{
    if (!p_surewarehk_Free) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_DH_EX_FREE,
                    ENGINE_R_NOT_INITIALISED);
    } else
        p_surewarehk_Free((char *)item, 1);
}
#  endif

/*
 * return number of decrypted bytes
 */
#  ifndef OPENSSL_NO_RSA
static int surewarehk_rsa_priv_dec(int flen, const unsigned char *from,
                                   unsigned char *to, RSA *rsa, int padding)
{
    int ret = 0, tlen;
    char *buf = NULL, *hptr = NULL;
    char msg[64] = "ENGINE_rsa_priv_dec";
    if (!p_surewarehk_Rsa_Priv_Dec) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_PRIV_DEC,
                    ENGINE_R_NOT_INITIALISED);
    }
    /* extract ref to private key */
    else if (!(hptr = RSA_get_ex_data(rsa, rsaHndidx))) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_PRIV_DEC,
                    SUREWARE_R_MISSING_KEY_COMPONENTS);
        goto err;
    }
    /* analyse what padding we can do into the hardware */
    if (padding == RSA_PKCS1_PADDING) {
        /* do it one shot */
        ret =
            p_surewarehk_Rsa_Priv_Dec(msg, flen, (unsigned char *)from, &tlen,
                                      to, hptr, SUREWARE_PKCS1_PAD);
        surewarehk_error_handling(msg, SUREWARE_F_SUREWAREHK_RSA_PRIV_DEC,
                                  ret);
        if (ret != 1)
            goto err;
        ret = tlen;
    } else {                    /* do with no padding into hardware */

        ret =
            p_surewarehk_Rsa_Priv_Dec(msg, flen, (unsigned char *)from, &tlen,
                                      to, hptr, SUREWARE_NO_PAD);
        surewarehk_error_handling(msg, SUREWARE_F_SUREWAREHK_RSA_PRIV_DEC,
                                  ret);
        if (ret != 1)
            goto err;
        /* intermediate buffer for padding */
        if ((buf = OPENSSL_malloc(tlen)) == NULL) {
            SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_PRIV_DEC,
                        ERR_R_MALLOC_FAILURE);
            goto err;
        }
        memcpy(buf, to, tlen);  /* transfert to into buf */
        switch (padding) {      /* check padding in software */
#   ifndef OPENSSL_NO_SHA
        case RSA_PKCS1_OAEP_PADDING:
            ret =
                RSA_padding_check_PKCS1_OAEP(to, tlen, (unsigned char *)buf,
                                             tlen, tlen, NULL, 0);
            break;
#   endif
        case RSA_SSLV23_PADDING:
            ret =
                RSA_padding_check_SSLv23(to, tlen, (unsigned char *)buf, flen,
                                         tlen);
            break;
        case RSA_NO_PADDING:
            ret =
                RSA_padding_check_none(to, tlen, (unsigned char *)buf, flen,
                                       tlen);
            break;
        default:
            SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_PRIV_DEC,
                        SUREWARE_R_UNKNOWN_PADDING_TYPE);
            goto err;
        }
        if (ret < 0)
            SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_PRIV_DEC,
                        SUREWARE_R_PADDING_CHECK_FAILED);
    }
 err:
    if (buf) {
        OPENSSL_cleanse(buf, tlen);
        OPENSSL_free(buf);
    }
    return ret;
}

/*
 * Does what OpenSSL rsa_priv_enc does.
 */
static int surewarehk_rsa_sign(int flen, const unsigned char *from,
                               unsigned char *to, RSA *rsa, int padding)
{
    int ret = 0, tlen;
    char *hptr = NULL;
    char msg[64] = "ENGINE_rsa_sign";
    if (!p_surewarehk_Rsa_Sign) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_SIGN, ENGINE_R_NOT_INITIALISED);
    }
    /* extract ref to private key */
    else if (!(hptr = RSA_get_ex_data(rsa, rsaHndidx))) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_SIGN,
                    SUREWARE_R_MISSING_KEY_COMPONENTS);
    } else {
        switch (padding) {
        case RSA_PKCS1_PADDING: /* do it in one shot */
            ret =
                p_surewarehk_Rsa_Sign(msg, flen, (unsigned char *)from, &tlen,
                                      to, hptr, SUREWARE_PKCS1_PAD);
            surewarehk_error_handling(msg, SUREWARE_F_SUREWAREHK_RSA_SIGN,
                                      ret);
            break;
        case RSA_NO_PADDING:
        default:
            SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_SIGN,
                        SUREWARE_R_UNKNOWN_PADDING_TYPE);
        }
    }
    return ret == 1 ? tlen : ret;
}

#  endif

#  ifndef OPENSSL_NO_DSA
/* DSA sign and verify */
static DSA_SIG *surewarehk_dsa_do_sign(const unsigned char *from, int flen,
                                       DSA *dsa)
{
    int ret = 0;
    char *hptr = NULL;
    DSA_SIG *psign = NULL;
    char msg[64] = "ENGINE_dsa_do_sign";
    if (!p_surewarehk_Dsa_Sign) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_DSA_DO_SIGN,
                    ENGINE_R_NOT_INITIALISED);
        goto err;
    }
    /* extract ref to private key */
    else if (!(hptr = DSA_get_ex_data(dsa, dsaHndidx))) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_DSA_DO_SIGN,
                    SUREWARE_R_MISSING_KEY_COMPONENTS);
        goto err;
    } else {
        if ((psign = DSA_SIG_new()) == NULL) {
            SUREWAREerr(SUREWARE_F_SUREWAREHK_DSA_DO_SIGN,
                        ERR_R_MALLOC_FAILURE);
            goto err;
        }
        psign->r = BN_new();
        psign->s = BN_new();
        if(!psign->r || !psign->s)
            goto err;
        bn_expand2(psign->r, 20 / sizeof(BN_ULONG));
        bn_expand2(psign->s, 20 / sizeof(BN_ULONG));
        if (psign->r->dmax != 20 / sizeof(BN_ULONG) ||
            psign->s->dmax != 20 / sizeof(BN_ULONG))
            goto err;
        ret = p_surewarehk_Dsa_Sign(msg, flen, from,
                                    (unsigned long *)psign->r->d,
                                    (unsigned long *)psign->s->d, hptr);
        surewarehk_error_handling(msg, SUREWARE_F_SUREWAREHK_DSA_DO_SIGN,
                                  ret);
    }
    psign->r->top = 20 / sizeof(BN_ULONG);
    bn_fix_top(psign->r);
    psign->s->top = 20 / sizeof(BN_ULONG);
    bn_fix_top(psign->s);

 err:
    if (psign) {
        DSA_SIG_free(psign);
        psign = NULL;
    }
    return psign;
}
#  endif

static int surewarehk_modexp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
                             const BIGNUM *m, BN_CTX *ctx)
{
    int ret = 0;
    char msg[64] = "ENGINE_modexp";
    if (!p_surewarehk_Mod_Exp) {
        SUREWAREerr(SUREWARE_F_SUREWAREHK_MODEXP, ENGINE_R_NOT_INITIALISED);
    } else if (r) {
        bn_expand2(r, m->top);
        if (r->dmax == m->top) {
            /* do it */
            ret = p_surewarehk_Mod_Exp(msg,
                                       m->top * sizeof(BN_ULONG),
                                       (unsigned long *)m->d,
                                       p->top * sizeof(BN_ULONG),
                                       (unsigned long *)p->d,
                                       a->top * sizeof(BN_ULONG),
                                       (unsigned long *)a->d,
                                       (unsigned long *)r->d);
            surewarehk_error_handling(msg, SUREWARE_F_SUREWAREHK_MODEXP, ret);
            if (ret == 1) {
                /* normalise result */
                r->top = m->top;
                bn_fix_top(r);
            }
        }
    }
    return ret;
}
# endif                         /* !OPENSSL_NO_HW_SureWare */
#endif                          /* !OPENSSL_NO_HW */