summaryrefslogtreecommitdiff
path: root/jni/ruby/ext/openssl/ossl_pkey_dh.c
blob: 084deec6f12d7d9f79bb524d21719632c472bf6d (plain)
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
/*
 * $Id: ossl_pkey_dh.c 47744 2014-09-30 05:25:32Z nobu $
 * 'OpenSSL for Ruby' project
 * Copyright (C) 2001-2002  Michal Rokos <m.rokos@sh.cvut.cz>
 * All rights reserved.
 */
/*
 * This program is licenced under the same licence as Ruby.
 * (See the file 'LICENCE'.)
 */
#if !defined(OPENSSL_NO_DH)

#include "ossl.h"

#define GetPKeyDH(obj, pkey) do { \
    GetPKey((obj), (pkey)); \
    if (EVP_PKEY_type((pkey)->type) != EVP_PKEY_DH) { /* PARANOIA? */ \
        ossl_raise(rb_eRuntimeError, "THIS IS NOT A DH!") ; \
    } \
while (0)

#define DH_HAS_PRIVATE(dh) ((dh)->priv_key)

#ifdef OSSL_ENGINE_ENABLED
#  define DH_PRIVATE(dh) (DH_HAS_PRIVATE(dh) || (dh)->engine)
#else
#  define DH_PRIVATE(dh) DH_HAS_PRIVATE(dh)
#endif


/*
 * Classes
 */
VALUE cDH;
VALUE eDHError;

/*
 * Public
 */
static VALUE
dh_instance(VALUE klass, DH *dh)
{
    EVP_PKEY *pkey;
    VALUE obj;

    if (!dh) {
        return Qfalse;
    }
    if (!(pkey = EVP_PKEY_new())) {
        return Qfalse;
    }
    if (!EVP_PKEY_assign_DH(pkey, dh)) {
        EVP_PKEY_free(pkey);
        return Qfalse;
    }
    WrapPKey(klass, obj, pkey);

    return obj;
}

VALUE
ossl_dh_new(EVP_PKEY *pkey)
{
    VALUE obj;

    if (!pkey) {
        obj = dh_instance(cDH, DH_new());
    } else {
        if (EVP_PKEY_type(pkey->type) != EVP_PKEY_DH) {
            ossl_raise(rb_eTypeError, "Not a DH key!");
        }
        WrapPKey(cDH, obj, pkey);
    }
    if (obj == Qfalse) {
        ossl_raise(eDHError, NULL);
    }

    return obj;
}

/*
 * Private
 */
#if defined(HAVE_DH_GENERATE_PARAMETERS_EX) && HAVE_BN_GENCB
struct dh_blocking_gen_arg {
    DH *dh;
    int size;
    int gen;
    BN_GENCB *cb;
    int result;
};

static void *
dh_blocking_gen(void *arg)
{
    struct dh_blocking_gen_arg *gen = (struct dh_blocking_gen_arg *)arg;
    gen->result = DH_generate_parameters_ex(gen->dh, gen->size, gen->gen, gen->cb);
    return 0;
}
#endif

static DH *
dh_generate(int size, int gen)
{
#if defined(HAVE_DH_GENERATE_PARAMETERS_EX) && HAVE_BN_GENCB
    BN_GENCB cb;
    struct ossl_generate_cb_arg cb_arg;
    struct dh_blocking_gen_arg gen_arg;
    DH *dh = DH_new();

    if (!dh) return 0;

    memset(&cb_arg, 0sizeof(struct ossl_generate_cb_arg));
    if (rb_block_given_p())
        cb_arg.yield = 1;
    BN_GENCB_set(&cb, ossl_generate_cb_2, &cb_arg);
    gen_arg.dh = dh;
    gen_arg.size = size;
    gen_arg.gen = gen;
    gen_arg.cb = &cb;
    if (cb_arg.yield == 1) {
        /* we cannot release GVL when callback proc is supplied */
        dh_blocking_gen(&gen_arg);
    } else {
        /* there's a chance to unblock */
        rb_thread_call_without_gvl(dh_blocking_gen, &gen_arg, ossl_generate_cb_stop, &cb_arg);
    }

    if (!gen_arg.result) {
        DH_free(dh);
        if (cb_arg.state) rb_jump_tag(cb_arg.state);
        return 0;
    }
#else
    DH *dh;

    dh = DH_generate_parameters(size, gen, rb_block_given_p() ? ossl_generate_cb : NULLNULL);
    if (!dh) return 0;
#endif

    if (!DH_generate_key(dh)) {
        DH_free(dh);
        return 0;
    }

    return dh;
}

/*
 *  call-seq:
 *     DH.generate(size [, generator]) -> dh
 *
 * Creates a new DH instance from scratch by generating the private and public
 * components alike.
 *
 * === Parameters
 * * +size+ is an integer representing the desired key size. Keys smaller than 1024 bits should be considered insecure.
 * * +generator+ is a small number > 1, typically 2 or 5.
 *
 */
static VALUE
ossl_dh_s_generate(int argc, VALUE *argv, VALUE klass)
{
    DH *dh ;
    int g = 2;
    VALUE size, gen, obj;

    if (rb_scan_args(argc, argv, "11", &size, &gen) == 2) {
        g = NUM2INT(gen);
    }
    dh = dh_generate(NUM2INT(size), g);
    obj = dh_instance(klass, dh);
    if (obj == Qfalse) {
        DH_free(dh);
        ossl_raise(eDHError, NULL);
    }

    return obj;
}

/*
 *  call-seq:
 *     DH.new([size [, generator] | string]) -> dh
 *
 * Either generates a DH instance from scratch or by reading already existing
 * DH parameters from +string+. Note that when reading a DH instance from
 * data that was encoded from a DH instance by using DH#to_pem or DH#to_der
 * the result will *not* contain a public/private key pair yet. This needs to
 * be generated using DH#generate_key! first.
 *
 * === Parameters
 * * +size+ is an integer representing the desired key size. Keys smaller than 1024 bits should be considered insecure.
 * * +generator+ is a small number > 1, typically 2 or 5.
 * * +string+ contains the DER or PEM encoded key.
 *
 * === Examples
 *  DH.new # -> dh
 *  DH.new(1024) # -> dh
 *  DH.new(1024, 5) # -> dh
 *  #Reading DH parameters
 *  dh = DH.new(File.read('parameters.pem')) # -> dh, but no public/private key yet
 *  dh.generate_key! # -> dh with public and private key
 */
static VALUE
ossl_dh_initialize(int argc, VALUE *argv, VALUE self)
{
    EVP_PKEY *pkey;
    DH *dh;
    int g = 2;
    BIO *in;
    VALUE arg, gen;

    GetPKey(self, pkey);
    if(rb_scan_args(argc, argv, "02", &arg, &gen) == 0) {
      dh = DH_new();
    }
    else if (FIXNUM_P(arg)) {
        if (!NIL_P(gen)) {
            g = NUM2INT(gen);
        }
        if (!(dh = dh_generate(FIX2INT(arg), g))) {
            ossl_raise(eDHError, NULL);
        }
    }
    else {
        arg = ossl_to_der_if_possible(arg);
        in = ossl_obj2bio(arg);
        dh = PEM_read_bio_DHparams(in, NULLNULLNULL);
        if (!dh){
            OSSL_BIO_reset(in);
            dh = d2i_DHparams_bio(in, NULL);
        }
        BIO_free(in);
        if (!dh) {
            ossl_raise(eDHError, NULL);
        }
    }
    if (!EVP_PKEY_assign_DH(pkey, dh)) {
        DH_free(dh);
        ossl_raise(eDHError, NULL);
    }
    return self;
}

/*
 *  call-seq:
 *     dh.public? -> true | false
 *
 * Indicates whether this DH instance has a public key associated with it or
 * not. The public key may be retrieved with DH#pub_key.
 */
static VALUE
ossl_dh_is_public(VALUE self)
{
    EVP_PKEY *pkey;

    GetPKeyDH(self, pkey);

    return (pkey->pkey.dh->pub_key) ? Qtrue : Qfalse;
}

/*
 *  call-seq:
 *     dh.private? -> true | false
 *
 * Indicates whether this DH instance has a private key associated with it or
 * not. The private key may be retrieved with DH#priv_key.
 */
static VALUE
ossl_dh_is_private(VALUE self)
{
    EVP_PKEY *pkey;

    GetPKeyDH(self, pkey);

    return (DH_PRIVATE(pkey->pkey.dh)) ? Qtrue : Qfalse;
}

/*
 *  call-seq:
 *     dh.export -> aString
 *     dh.to_pem -> aString
 *     dh.to_s -> aString
 *
 * Encodes this DH to its PEM encoding. Note that any existing per-session
 * public/private keys will *not* get encoded, just the Diffie-Hellman
 * parameters will be encoded.
 */
static VALUE
ossl_dh_export(VALUE self)
{
    EVP_PKEY *pkey;
    BIO *out;
    VALUE str;

    GetPKeyDH(self, pkey);
    if (!(out = BIO_new(BIO_s_mem()))) {
        ossl_raise(eDHError, NULL);
    }
    if (!PEM_write_bio_DHparams(out, pkey->pkey.dh)) {
        BIO_free(out);
        ossl_raise(eDHError, NULL);
    }
    str = ossl_membio2str(out);

    return str;
}

/*
 *  call-seq:
 *     dh.to_der -> aString
 *
 * Encodes this DH to its DER encoding. Note that any existing per-session
 * public/private keys will *not* get encoded, just the Diffie-Hellman
 * parameters will be encoded.

 */
static VALUE
ossl_dh_to_der(VALUE self)
{
    EVP_PKEY *pkey;
    unsigned char *p;
    long len;
    VALUE str;

    GetPKeyDH(self, pkey);
    if((len = i2d_DHparams(pkey->pkey.dh, NULL)) <= 0)
        ossl_raise(eDHError, NULL);
    str = rb_str_new(0, len);
    p = (unsigned char *)RSTRING_PTR(str);
    if(i2d_DHparams(pkey->pkey.dh, &p) < 0)
        ossl_raise(eDHError, NULL);
    ossl_str_adjust(str, p);

    return str;
}

/*
 *  call-seq:
 *     dh.params -> hash
 *
 * Stores all parameters of key to the hash
 * INSECURE: PRIVATE INFORMATIONS CAN LEAK OUT!!!
 * Don't use :-)) (I's up to you)
 */
static VALUE
ossl_dh_get_params(VALUE self)
{
    EVP_PKEY *pkey;
    VALUE hash;

    GetPKeyDH(self, pkey);

    hash = rb_hash_new();

    rb_hash_aset(hash, rb_str_new2("p"), ossl_bn_new(pkey->pkey.dh->p));
    rb_hash_aset(hash, rb_str_new2("g"), ossl_bn_new(pkey->pkey.dh->g));
    rb_hash_aset(hash, rb_str_new2("pub_key"), ossl_bn_new(pkey->pkey.dh->pub_key));
    rb_hash_aset(hash, rb_str_new2("priv_key"), ossl_bn_new(pkey->pkey.dh->priv_key));

    return hash;
}

/*
 *  call-seq:
 *     dh.to_text -> aString
 *
 * Prints all parameters of key to buffer
 * INSECURE: PRIVATE INFORMATIONS CAN LEAK OUT!!!
 * Don't use :-)) (I's up to you)
 */
static VALUE
ossl_dh_to_text(VALUE self)
{
    EVP_PKEY *pkey;
    BIO *out;
    VALUE str;

    GetPKeyDH(self, pkey);
    if (!(out = BIO_new(BIO_s_mem()))) {
        ossl_raise(eDHError, NULL);
    }
    if (!DHparams_print(out, pkey->pkey.dh)) {
        BIO_free(out);
        ossl_raise(eDHError, NULL);
    }
    str = ossl_membio2str(out);

    return str;
}

/*
 *  call-seq:
 *     dh.public_key -> aDH
 *
 * Returns a new DH instance that carries just the public information, i.e.
 * the prime +p+ and the generator +g+, but no public/private key yet. Such
 * a pair may be generated using DH#generate_key!. The "public key" needed
 * for a key exchange with DH#compute_key is considered as per-session
 * information and may be retrieved with DH#pub_key once a key pair has
 * been generated.
 * If the current instance already contains private information (and thus a
 * valid public/private key pair), this information will no longer be present
 * in the new instance generated by DH#public_key. This feature is helpful for
 * publishing the Diffie-Hellman parameters without leaking any of the private
 * per-session information.
 *
 * === Example
 *  dh = OpenSSL::PKey::DH.new(2048) # has public and private key set
 *  public_key = dh.public_key # contains only prime and generator
 *  parameters = public_key.to_der # it's safe to publish this
 */
static VALUE
ossl_dh_to_public_key(VALUE self)
{
    EVP_PKEY *pkey;
    DH *dh;
    VALUE obj;

    GetPKeyDH(self, pkey);
    dh = DHparams_dup(pkey->pkey.dh); /* err check perfomed by dh_instance */
    obj = dh_instance(CLASS_OF(self), dh);
    if (obj == Qfalse) {
        DH_free(dh);
        ossl_raise(eDHError, NULL);
    }

    return obj;
}

/*
 *  call-seq:
 *     dh.params_ok? -> true | false
 *
 * Validates the Diffie-Hellman parameters associated with this instance.
 * It checks whether a safe prime and a suitable generator are used. If this
 * is not the case, +false+ is returned.
 */
static VALUE
ossl_dh_check_params(VALUE self)
{
    DH *dh;
    EVP_PKEY *pkey;
    int codes;

    GetPKeyDH(self, pkey);
    dh = pkey->pkey.dh;

    if (!DH_check(dh, &codes)) {
        return Qfalse;
    }

    return codes == 0 ? Qtrue : Qfalse;
}

/*
 *  call-seq:
 *     dh.generate_key! -> self
 *
 * Generates a private and public key unless a private key already exists.
 * If this DH instance was generated from public DH parameters (e.g. by
 * encoding the result of DH#public_key), then this method needs to be
 * called first in order to generate the per-session keys before performing
 * the actual key exchange.
 *
 * === Example
 *   dh = OpenSSL::PKey::DH.new(2048)
 *   public_key = dh.public_key #contains no private/public key yet
 *   public_key.generate_key!
 *   puts public_key.private? # => true
 */
static VALUE
ossl_dh_generate_key(VALUE self)
{
    DH *dh;
    EVP_PKEY *pkey;

    GetPKeyDH(self, pkey);
    dh = pkey->pkey.dh;

    if (!DH_generate_key(dh))
        ossl_raise(eDHError, "Failed to generate key");
    return self;
}

/*
 *  call-seq:
 *     dh.compute_key(pub_bn) -> aString
 *
 * Returns a String containing a shared secret computed from the other party's public value.
 * See DH_compute_key() for further information.
 *
 * === Parameters
 * * +pub_bn+ is a OpenSSL::BN, *not* the DH instance returned by
 * DH#public_key as that contains the DH parameters only.
 */
static VALUE
ossl_dh_compute_key(VALUE self, VALUE pub)
{
    DH *dh;
    EVP_PKEY *pkey;
    BIGNUM *pub_key;
    VALUE str;
    int len;

    GetPKeyDH(self, pkey);
    dh = pkey->pkey.dh;
    pub_key = GetBNPtr(pub);
    len = DH_size(dh);
    str = rb_str_new(0, len);
    if ((len = DH_compute_key((unsigned char *)RSTRING_PTR(str), pub_key, dh)) < 0) {
        ossl_raise(eDHError, NULL);
    }
    rb_str_set_len(str, len);

    return str;
}

OSSL_PKEY_BN(dh, p)
OSSL_PKEY_BN(dh, g)
OSSL_PKEY_BN(dh, pub_key)
OSSL_PKEY_BN(dh, priv_key)

/*
 * -----BEGIN DH PARAMETERS-----
 * MEYCQQD0zXHljRg/mJ9PYLACLv58Cd8VxBxxY7oEuCeURMiTqEhMym16rhhKgZG2
 * zk2O9uUIBIxSj+NKMURHGaFKyIvLAgEC
 * -----END DH PARAMETERS-----
 */
static unsigned char DEFAULT_DH_512_PRIM[] = {
    0xf40xcd0x710xe50x8d0x180x3f0x98,
    0x9f0x4f0x600xb00x020x2e0xfe0x7c,
    0x090xdf0x150xc40x1c0x710x630xba,
    0x040xb80x270x940x440xc80x930xa8,
    0x480x4c0xca0x6d0x7a0xae0x180x4a,
    0x810x910xb60xce0x4d0x8e0xf60xe5,
    0x080x040x8c0x520x8f0xe30x4a0x31,
    0x440x470x190xa10x4a0xc80x8b0xcb,
};
static unsigned char DEFAULT_DH_512_GEN[] = { 0x02 };
DH *OSSL_DEFAULT_DH_512 = NULL;

/*
 * -----BEGIN DH PARAMETERS-----
 * MIGHAoGBAJ0lOVy0VIr/JebWn0zDwY2h+rqITFOpdNr6ugsgvkDXuucdcChhYExJ
 * AV/ZD2AWPbrTqV76mGRgJg4EddgT1zG0jq3rnFdMj2XzkBYx3BVvfR0Arnby0RHR
 * T4h7KZ/2zmjvV+eF8kBUHBJAojUlzxKj4QeO2x20FP9X5xmNUXeDAgEC
 * -----END DH PARAMETERS-----
 */
static unsigned char DEFAULT_DH_1024_PRIM[] = {
    0x9d0x250x390x5c0xb40x540x8a0xff,
    0x250xe60xd60x9f0x4c0xc30xc10x8d,
    0xa10xfa0xba0x880x4c0x530xa90x74,
    0xda0xfa0xba0x0b0x200xbe0x400xd7,
    0xba0xe70x1d0x700x280x610x600x4c,
    0x490x010x5f0xd90x0f0x600x160x3d,
    0xba0xd30xa90x5e0xfa0x980x640x60,
    0x260x0e0x040x750xd80x130xd70x31,
    0xb40x8e0xad0xeb0x9c0x570x4c0x8f,
    0x650xf30x900x160x310xdc0x150x6f,
    0x7d0x1d0x000xae0x760xf20xd10x11,
    0xd10x4f0x880x7b0x290x9f0xf60xce,
    0x680xef0x570xe70x850xf20x400x54,
    0x1c0x120x400xa20x350x250xcf0x12,
    0xa30xe10x070x8e0xdb0x1d0xb40x14,
    0xff0x570xe70x190x8d0x510x770x83
};
static unsigned char DEFAULT_DH_1024_GEN[] = { 0x02 };
DH *OSSL_DEFAULT_DH_1024 = NULL;

static DH*
ossl_create_dh(unsigned char *p, size_t plen, unsigned char *g, size_t glen)
{
    DH *dh;

    if ((dh = DH_new()) == NULL) ossl_raise(eDHError, NULL);
    dh->p = BN_bin2bn(p, rb_long2int(plen), NULL);
    dh->g = BN_bin2bn(g, rb_long2int(glen), NULL);
    if (dh->p == NULL || dh->g == NULL){
        DH_free(dh);
        ossl_raise(eDHError, NULL);
    }

    return dh;
}

/*
 * INIT
 */
void
Init_ossl_dh(void)
{
#if 0
    mOSSL = rb_define_module("OpenSSL"); /* let rdoc know about mOSSL and mPKey */
    mPKey = rb_define_module_under(mOSSL, "PKey");
#endif

    /* Document-class: OpenSSL::PKey::DHError
     *
     * Generic exception that is raised if an operation on a DH PKey
     * fails unexpectedly or in case an instantiation of an instance of DH
     * fails due to non-conformant input data.
     */
    eDHError = rb_define_class_under(mPKey, "DHError", ePKeyError);
    /* Document-class: OpenSSL::PKey::DH
     *
     * An implementation of the Diffie-Hellman key exchange protocol based on
     * discrete logarithms in finite fields, the same basis that DSA is built
     * on.
     *
     * === Accessor methods for the Diffie-Hellman parameters
     * * DH#p
     * The prime (an OpenSSL::BN) of the Diffie-Hellman parameters.
     * * DH#g
     * The generator (an OpenSSL::BN) g of the Diffie-Hellman parameters.
     * * DH#pub_key
     * The per-session public key (an OpenSSL::BN) matching the private key.
     * This needs to be passed to DH#compute_key.
     * * DH#priv_key
     * The per-session private key, an OpenSSL::BN.
     *
     * === Example of a key exchange
     *  dh1 = OpenSSL::PKey::DH.new(2048)
     *  der = dh1.public_key.to_der #you may send this publicly to the participating party
     *  dh2 = OpenSSL::PKey::DH.new(der)
     *  dh2.generate_key! #generate the per-session key pair
     *  symm_key1 = dh1.compute_key(dh2.pub_key)
     *  symm_key2 = dh2.compute_key(dh1.pub_key)
     *
     *  puts symm_key1 == symm_key2 # => true
     */
    cDH = rb_define_class_under(mPKey, "DH", cPKey);
    rb_define_singleton_method(cDH, "generate", ossl_dh_s_generate, -1);
    rb_define_method(cDH, "initialize", ossl_dh_initialize, -1);
    rb_define_method(cDH, "public?", ossl_dh_is_public, 0);
    rb_define_method(cDH, "private?", ossl_dh_is_private, 0);
    rb_define_method(cDH, "to_text", ossl_dh_to_text, 0);
    rb_define_method(cDH, "export", ossl_dh_export, 0);
    rb_define_alias(cDH, "to_pem""export");
    rb_define_alias(cDH, "to_s""export");
    rb_define_method(cDH, "to_der", ossl_dh_to_der, 0);
    rb_define_method(cDH, "public_key", ossl_dh_to_public_key, 0);
    rb_define_method(cDH, "params_ok?", ossl_dh_check_params, 0);
    rb_define_method(cDH, "generate_key!", ossl_dh_generate_key, 0);
    rb_define_method(cDH, "compute_key", ossl_dh_compute_key, 1);

    DEF_OSSL_PKEY_BN(cDH, dh, p);
    DEF_OSSL_PKEY_BN(cDH, dh, g);
    DEF_OSSL_PKEY_BN(cDH, dh, pub_key);
    DEF_OSSL_PKEY_BN(cDH, dh, priv_key);
    rb_define_method(cDH, "params", ossl_dh_get_params, 0);

    OSSL_DEFAULT_DH_512 = ossl_create_dh(
        DEFAULT_DH_512_PRIM, sizeof(DEFAULT_DH_512_PRIM),
        DEFAULT_DH_512_GEN, sizeof(DEFAULT_DH_512_GEN));
    OSSL_DEFAULT_DH_1024 = ossl_create_dh(
        DEFAULT_DH_1024_PRIM, sizeof(DEFAULT_DH_1024_PRIM),
        DEFAULT_DH_1024_GEN, sizeof(DEFAULT_DH_1024_GEN));
}

#else /* defined NO_DH */
void
Init_ossl_dh(void)
{
}
#endif /* NO_DH */