1/*
2 * Copyright 2006-2016 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10#include <stdio.h>
11#include "internal/cryptlib.h"
12#include <openssl/x509.h>
13#include <openssl/asn1.h>
14#include "dh_local.h"
15#include <openssl/bn.h>
16#include "crypto/asn1.h"
17#include "crypto/evp.h"
18#include <openssl/cms.h>
19#include <openssl/core_names.h>
20#include "internal/param_build.h"
21
22/*
23 * i2d/d2i like DH parameter functions which use the appropriate routine for
24 * PKCS#3 DH or X9.42 DH.
25 */
26
27static DH *d2i_dhp(const EVP_PKEY *pkey, const unsigned char **pp,
28 long length)
29{
30 if (pkey->ameth == &dhx_asn1_meth)
31 return d2i_DHxparams(NULL, pp, length);
32 return d2i_DHparams(NULL, pp, length);
33}
34
35static int i2d_dhp(const EVP_PKEY *pkey, const DH *a, unsigned char **pp)
36{
37 if (pkey->ameth == &dhx_asn1_meth)
38 return i2d_DHxparams(a, pp);
39 return i2d_DHparams(a, pp);
40}
41
42static void int_dh_free(EVP_PKEY *pkey)
43{
44 DH_free(pkey->pkey.dh);
45}
46
47static int dh_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
48{
49 const unsigned char *p, *pm;
50 int pklen, pmlen;
51 int ptype;
52 const void *pval;
53 const ASN1_STRING *pstr;
54 X509_ALGOR *palg;
55 ASN1_INTEGER *public_key = NULL;
56
57 DH *dh = NULL;
58
59 if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
60 return 0;
61 X509_ALGOR_get0(NULL, &ptype, &pval, palg);
62
63 if (ptype != V_ASN1_SEQUENCE) {
64 DHerr(DH_F_DH_PUB_DECODE, DH_R_PARAMETER_ENCODING_ERROR);
65 goto err;
66 }
67
68 pstr = pval;
69 pm = pstr->data;
70 pmlen = pstr->length;
71
72 if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL) {
73 DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
74 goto err;
75 }
76
77 if ((public_key = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL) {
78 DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
79 goto err;
80 }
81
82 /* We have parameters now set public key */
83 if ((dh->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
84 DHerr(DH_F_DH_PUB_DECODE, DH_R_BN_DECODE_ERROR);
85 goto err;
86 }
87
88 ASN1_INTEGER_free(public_key);
89 EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
90 return 1;
91
92 err:
93 ASN1_INTEGER_free(public_key);
94 DH_free(dh);
95 return 0;
96
97}
98
99static int dh_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
100{
101 DH *dh;
102 int ptype;
103 unsigned char *penc = NULL;
104 int penclen;
105 ASN1_STRING *str;
106 ASN1_INTEGER *pub_key = NULL;
107
108 dh = pkey->pkey.dh;
109
110 str = ASN1_STRING_new();
111 if (str == NULL) {
112 DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
113 goto err;
114 }
115 str->length = i2d_dhp(pkey, dh, &str->data);
116 if (str->length <= 0) {
117 DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
118 goto err;
119 }
120 ptype = V_ASN1_SEQUENCE;
121
122 pub_key = BN_to_ASN1_INTEGER(dh->pub_key, NULL);
123 if (pub_key == NULL)
124 goto err;
125
126 penclen = i2d_ASN1_INTEGER(pub_key, &penc);
127
128 ASN1_INTEGER_free(pub_key);
129
130 if (penclen <= 0) {
131 DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
132 goto err;
133 }
134
135 if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
136 ptype, str, penc, penclen))
137 return 1;
138
139 err:
140 OPENSSL_free(penc);
141 ASN1_STRING_free(str);
142
143 return 0;
144}
145
146/*
147 * PKCS#8 DH is defined in PKCS#11 of all places. It is similar to DH in that
148 * the AlgorithmIdentifier contains the parameters, the private key is
149 * explicitly included and the pubkey must be recalculated.
150 */
151
152static int dh_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
153{
154 const unsigned char *p, *pm;
155 int pklen, pmlen;
156 int ptype;
157 const void *pval;
158 const ASN1_STRING *pstr;
159 const X509_ALGOR *palg;
160 ASN1_INTEGER *privkey = NULL;
161 DH *dh = NULL;
162
163 if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
164 return 0;
165
166 X509_ALGOR_get0(NULL, &ptype, &pval, palg);
167
168 if (ptype != V_ASN1_SEQUENCE)
169 goto decerr;
170 if ((privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL)
171 goto decerr;
172
173 pstr = pval;
174 pm = pstr->data;
175 pmlen = pstr->length;
176 if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL)
177 goto decerr;
178
179 /* We have parameters now set private key */
180 if ((dh->priv_key = BN_secure_new()) == NULL
181 || !ASN1_INTEGER_to_BN(privkey, dh->priv_key)) {
182 DHerr(DH_F_DH_PRIV_DECODE, DH_R_BN_ERROR);
183 goto dherr;
184 }
185 /* Calculate public key, increments dirty_cnt */
186 if (!DH_generate_key(dh))
187 goto dherr;
188
189 EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
190
191 ASN1_STRING_clear_free(privkey);
192
193 return 1;
194
195 decerr:
196 DHerr(DH_F_DH_PRIV_DECODE, EVP_R_DECODE_ERROR);
197 dherr:
198 DH_free(dh);
199 ASN1_STRING_clear_free(privkey);
200 return 0;
201}
202
203static int dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
204{
205 ASN1_STRING *params = NULL;
206 ASN1_INTEGER *prkey = NULL;
207 unsigned char *dp = NULL;
208 int dplen;
209
210 params = ASN1_STRING_new();
211
212 if (params == NULL) {
213 DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
214 goto err;
215 }
216
217 params->length = i2d_dhp(pkey, pkey->pkey.dh, &params->data);
218 if (params->length <= 0) {
219 DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
220 goto err;
221 }
222 params->type = V_ASN1_SEQUENCE;
223
224 /* Get private key into integer */
225 prkey = BN_to_ASN1_INTEGER(pkey->pkey.dh->priv_key, NULL);
226
227 if (prkey == NULL) {
228 DHerr(DH_F_DH_PRIV_ENCODE, DH_R_BN_ERROR);
229 goto err;
230 }
231
232 dplen = i2d_ASN1_INTEGER(prkey, &dp);
233
234 ASN1_STRING_clear_free(prkey);
235 prkey = NULL;
236
237 if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
238 V_ASN1_SEQUENCE, params, dp, dplen))
239 goto err;
240
241 return 1;
242
243 err:
244 OPENSSL_free(dp);
245 ASN1_STRING_free(params);
246 ASN1_STRING_clear_free(prkey);
247 return 0;
248}
249
250static int dh_param_decode(EVP_PKEY *pkey,
251 const unsigned char **pder, int derlen)
252{
253 DH *dh;
254
255 if ((dh = d2i_dhp(pkey, pder, derlen)) == NULL) {
256 DHerr(DH_F_DH_PARAM_DECODE, ERR_R_DH_LIB);
257 return 0;
258 }
259 dh->dirty_cnt++;
260 EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
261 return 1;
262}
263
264static int dh_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
265{
266 return i2d_dhp(pkey, pkey->pkey.dh, pder);
267}
268
269static int do_dh_print(BIO *bp, const DH *x, int indent, int ptype)
270{
271 int reason = ERR_R_BUF_LIB;
272 const char *ktype = NULL;
273 BIGNUM *priv_key, *pub_key;
274
275 if (ptype == 2)
276 priv_key = x->priv_key;
277 else
278 priv_key = NULL;
279
280 if (ptype > 0)
281 pub_key = x->pub_key;
282 else
283 pub_key = NULL;
284
285 if (x->p == NULL || (ptype == 2 && priv_key == NULL)
286 || (ptype > 0 && pub_key == NULL)) {
287 reason = ERR_R_PASSED_NULL_PARAMETER;
288 goto err;
289 }
290
291 if (ptype == 2)
292 ktype = "DH Private-Key";
293 else if (ptype == 1)
294 ktype = "DH Public-Key";
295 else
296 ktype = "DH Parameters";
297
298 BIO_indent(bp, indent, 128);
299 if (BIO_printf(bp, "%s: (%d bit)\n", ktype, BN_num_bits(x->p)) <= 0)
300 goto err;
301 indent += 4;
302
303 if (!ASN1_bn_print(bp, "private-key:", priv_key, NULL, indent))
304 goto err;
305 if (!ASN1_bn_print(bp, "public-key:", pub_key, NULL, indent))
306 goto err;
307
308 if (!ASN1_bn_print(bp, "prime:", x->p, NULL, indent))
309 goto err;
310 if (!ASN1_bn_print(bp, "generator:", x->g, NULL, indent))
311 goto err;
312 if (x->q && !ASN1_bn_print(bp, "subgroup order:", x->q, NULL, indent))
313 goto err;
314 if (x->j && !ASN1_bn_print(bp, "subgroup factor:", x->j, NULL, indent))
315 goto err;
316 if (x->seed) {
317 int i;
318 BIO_indent(bp, indent, 128);
319 BIO_puts(bp, "seed:");
320 for (i = 0; i < x->seedlen; i++) {
321 if ((i % 15) == 0) {
322 if (BIO_puts(bp, "\n") <= 0
323 || !BIO_indent(bp, indent + 4, 128))
324 goto err;
325 }
326 if (BIO_printf(bp, "%02x%s", x->seed[i],
327 ((i + 1) == x->seedlen) ? "" : ":") <= 0)
328 goto err;
329 }
330 if (BIO_write(bp, "\n", 1) <= 0)
331 return 0;
332 }
333 if (x->counter && !ASN1_bn_print(bp, "counter:", x->counter, NULL, indent))
334 goto err;
335 if (x->length != 0) {
336 BIO_indent(bp, indent, 128);
337 if (BIO_printf(bp, "recommended-private-length: %d bits\n",
338 (int)x->length) <= 0)
339 goto err;
340 }
341
342 return 1;
343
344 err:
345 DHerr(DH_F_DO_DH_PRINT, reason);
346 return 0;
347}
348
349static int int_dh_size(const EVP_PKEY *pkey)
350{
351 return DH_size(pkey->pkey.dh);
352}
353
354static int dh_bits(const EVP_PKEY *pkey)
355{
356 return BN_num_bits(pkey->pkey.dh->p);
357}
358
359static int dh_security_bits(const EVP_PKEY *pkey)
360{
361 return DH_security_bits(pkey->pkey.dh);
362}
363
364static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
365{
366 if (BN_cmp(a->pkey.dh->p, b->pkey.dh->p) ||
367 BN_cmp(a->pkey.dh->g, b->pkey.dh->g))
368 return 0;
369 else if (a->ameth == &dhx_asn1_meth) {
370 if (BN_cmp(a->pkey.dh->q, b->pkey.dh->q))
371 return 0;
372 }
373 return 1;
374}
375
376static int int_dh_bn_cpy(BIGNUM **dst, const BIGNUM *src)
377{
378 BIGNUM *a;
379
380 /*
381 * If source is read only just copy the pointer, so
382 * we don't have to reallocate it.
383 */
384 if (src == NULL)
385 a = NULL;
386 else if (BN_get_flags(src, BN_FLG_STATIC_DATA)
387 && !BN_get_flags(src, BN_FLG_MALLOCED))
388 a = (BIGNUM *)src;
389 else if ((a = BN_dup(src)) == NULL)
390 return 0;
391 BN_clear_free(*dst);
392 *dst = a;
393 return 1;
394}
395
396static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
397{
398 if (is_x942 == -1)
399 is_x942 = ! !from->q;
400 if (!int_dh_bn_cpy(&to->p, from->p))
401 return 0;
402 if (!int_dh_bn_cpy(&to->g, from->g))
403 return 0;
404 if (is_x942) {
405 if (!int_dh_bn_cpy(&to->q, from->q))
406 return 0;
407 if (!int_dh_bn_cpy(&to->j, from->j))
408 return 0;
409 OPENSSL_free(to->seed);
410 to->seed = NULL;
411 to->seedlen = 0;
412 if (from->seed) {
413 to->seed = OPENSSL_memdup(from->seed, from->seedlen);
414 if (!to->seed)
415 return 0;
416 to->seedlen = from->seedlen;
417 }
418 } else
419 to->length = from->length;
420 to->dirty_cnt++;
421 return 1;
422}
423
424DH *DHparams_dup(const DH *dh)
425{
426 DH *ret;
427 ret = DH_new();
428 if (ret == NULL)
429 return NULL;
430 if (!int_dh_param_copy(ret, dh, -1)) {
431 DH_free(ret);
432 return NULL;
433 }
434 return ret;
435}
436
437static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
438{
439 if (to->pkey.dh == NULL) {
440 to->pkey.dh = DH_new();
441 if (to->pkey.dh == NULL)
442 return 0;
443 }
444 return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
445 from->ameth == &dhx_asn1_meth);
446}
447
448static int dh_missing_parameters(const EVP_PKEY *a)
449{
450 if (a->pkey.dh == NULL || a->pkey.dh->p == NULL || a->pkey.dh->g == NULL)
451 return 1;
452 return 0;
453}
454
455static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
456{
457 if (dh_cmp_parameters(a, b) == 0)
458 return 0;
459 if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
460 return 0;
461 else
462 return 1;
463}
464
465static int dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
466 ASN1_PCTX *ctx)
467{
468 return do_dh_print(bp, pkey->pkey.dh, indent, 0);
469}
470
471static int dh_public_print(BIO *bp, const EVP_PKEY *pkey, int indent,
472 ASN1_PCTX *ctx)
473{
474 return do_dh_print(bp, pkey->pkey.dh, indent, 1);
475}
476
477static int dh_private_print(BIO *bp, const EVP_PKEY *pkey, int indent,
478 ASN1_PCTX *ctx)
479{
480 return do_dh_print(bp, pkey->pkey.dh, indent, 2);
481}
482
483int DHparams_print(BIO *bp, const DH *x)
484{
485 return do_dh_print(bp, x, 4, 0);
486}
487
488#ifndef OPENSSL_NO_CMS
489static int dh_cms_decrypt(CMS_RecipientInfo *ri);
490static int dh_cms_encrypt(CMS_RecipientInfo *ri);
491#endif
492
493static int dh_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
494{
495 switch (op) {
496 case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
497 return dh_buf2key(EVP_PKEY_get0_DH(pkey), arg2, arg1);
498 case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
499 return dh_key2buf(EVP_PKEY_get0_DH(pkey), arg2);
500 default:
501 return -2;
502 }
503}
504
505static int dhx_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
506{
507 switch (op) {
508#ifndef OPENSSL_NO_CMS
509
510 case ASN1_PKEY_CTRL_CMS_ENVELOPE:
511 if (arg1 == 1)
512 return dh_cms_decrypt(arg2);
513 else if (arg1 == 0)
514 return dh_cms_encrypt(arg2);
515 return -2;
516
517 case ASN1_PKEY_CTRL_CMS_RI_TYPE:
518 *(int *)arg2 = CMS_RECIPINFO_AGREE;
519 return 1;
520#endif
521 default:
522 return -2;
523 }
524
525}
526
527static int dh_pkey_public_check(const EVP_PKEY *pkey)
528{
529 DH *dh = pkey->pkey.dh;
530
531 if (dh->pub_key == NULL) {
532 DHerr(DH_F_DH_PKEY_PUBLIC_CHECK, DH_R_MISSING_PUBKEY);
533 return 0;
534 }
535
536 return DH_check_pub_key_ex(dh, dh->pub_key);
537}
538
539static int dh_pkey_param_check(const EVP_PKEY *pkey)
540{
541 DH *dh = pkey->pkey.dh;
542
543 return DH_check_ex(dh);
544}
545
546static size_t dh_pkey_dirty_cnt(const EVP_PKEY *pkey)
547{
548 return pkey->pkey.dh->dirty_cnt;
549}
550
551static void *dh_pkey_export_to(const EVP_PKEY *pk, EVP_KEYMGMT *keymgmt,
552 int want_domainparams)
553{
554 DH *dh = pk->pkey.dh;
555 OSSL_PARAM_BLD tmpl;
556 const BIGNUM *p = DH_get0_p(dh), *g = DH_get0_g(dh), *q = DH_get0_q(dh);
557 const BIGNUM *pub_key = DH_get0_pub_key(dh);
558 const BIGNUM *priv_key = DH_get0_priv_key(dh);
559 OSSL_PARAM *params;
560 void *provdata = NULL;
561
562 if (p == NULL || g == NULL)
563 return NULL;
564
565 ossl_param_bld_init(&tmpl);
566 if (!ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_FFC_P, p)
567 || !ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_FFC_G, g))
568 return NULL;
569 if (q != NULL) {
570 if (!ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_FFC_Q, q))
571 return NULL;
572 }
573
574 if (!want_domainparams) {
575 /* A key must at least have a public part. */
576 if (!ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_DH_PUB_KEY,
577 pub_key))
578 return NULL;
579
580 if (priv_key != NULL) {
581 if (!ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_DH_PRIV_KEY,
582 priv_key))
583 return NULL;
584 }
585 }
586
587 params = ossl_param_bld_to_param(&tmpl);
588
589 /* We export, the provider imports */
590 provdata = want_domainparams
591 ? evp_keymgmt_importdomparams(keymgmt, params)
592 : evp_keymgmt_importkey(keymgmt, params);
593
594 ossl_param_bld_free(params);
595 return provdata;
596}
597
598const EVP_PKEY_ASN1_METHOD dh_asn1_meth = {
599 EVP_PKEY_DH,
600 EVP_PKEY_DH,
601 0,
602
603 "DH",
604 "OpenSSL PKCS#3 DH method",
605
606 dh_pub_decode,
607 dh_pub_encode,
608 dh_pub_cmp,
609 dh_public_print,
610
611 dh_priv_decode,
612 dh_priv_encode,
613 dh_private_print,
614
615 int_dh_size,
616 dh_bits,
617 dh_security_bits,
618
619 dh_param_decode,
620 dh_param_encode,
621 dh_missing_parameters,
622 dh_copy_parameters,
623 dh_cmp_parameters,
624 dh_param_print,
625 0,
626
627 int_dh_free,
628 dh_pkey_ctrl,
629
630 0, 0, 0, 0, 0,
631
632 0,
633 dh_pkey_public_check,
634 dh_pkey_param_check,
635
636 0, 0, 0, 0,
637
638 dh_pkey_dirty_cnt,
639 dh_pkey_export_to,
640};
641
642const EVP_PKEY_ASN1_METHOD dhx_asn1_meth = {
643 EVP_PKEY_DHX,
644 EVP_PKEY_DHX,
645 0,
646
647 "X9.42 DH",
648 "OpenSSL X9.42 DH method",
649
650 dh_pub_decode,
651 dh_pub_encode,
652 dh_pub_cmp,
653 dh_public_print,
654
655 dh_priv_decode,
656 dh_priv_encode,
657 dh_private_print,
658
659 int_dh_size,
660 dh_bits,
661 dh_security_bits,
662
663 dh_param_decode,
664 dh_param_encode,
665 dh_missing_parameters,
666 dh_copy_parameters,
667 dh_cmp_parameters,
668 dh_param_print,
669 0,
670
671 int_dh_free,
672 dhx_pkey_ctrl,
673
674 0, 0, 0, 0, 0,
675
676 0,
677 dh_pkey_public_check,
678 dh_pkey_param_check
679};
680
681#ifndef OPENSSL_NO_CMS
682
683static int dh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
684 X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
685{
686 const ASN1_OBJECT *aoid;
687 int atype;
688 const void *aval;
689 ASN1_INTEGER *public_key = NULL;
690 int rv = 0;
691 EVP_PKEY *pkpeer = NULL, *pk = NULL;
692 DH *dhpeer = NULL;
693 const unsigned char *p;
694 int plen;
695
696 X509_ALGOR_get0(&aoid, &atype, &aval, alg);
697 if (OBJ_obj2nid(aoid) != NID_dhpublicnumber)
698 goto err;
699 /* Only absent parameters allowed in RFC XXXX */
700 if (atype != V_ASN1_UNDEF && atype == V_ASN1_NULL)
701 goto err;
702
703 pk = EVP_PKEY_CTX_get0_pkey(pctx);
704 if (pk == NULL)
705 goto err;
706 if (pk->type != EVP_PKEY_DHX)
707 goto err;
708 /* Get parameters from parent key */
709 dhpeer = DHparams_dup(pk->pkey.dh);
710 /* We have parameters now set public key */
711 plen = ASN1_STRING_length(pubkey);
712 p = ASN1_STRING_get0_data(pubkey);
713 if (p == NULL || plen == 0)
714 goto err;
715
716 if ((public_key = d2i_ASN1_INTEGER(NULL, &p, plen)) == NULL) {
717 DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_DECODE_ERROR);
718 goto err;
719 }
720
721 /* We have parameters now set public key */
722 if ((dhpeer->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
723 DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_BN_DECODE_ERROR);
724 goto err;
725 }
726
727 pkpeer = EVP_PKEY_new();
728 if (pkpeer == NULL)
729 goto err;
730 EVP_PKEY_assign(pkpeer, pk->ameth->pkey_id, dhpeer);
731 dhpeer = NULL;
732 if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
733 rv = 1;
734 err:
735 ASN1_INTEGER_free(public_key);
736 EVP_PKEY_free(pkpeer);
737 DH_free(dhpeer);
738 return rv;
739}
740
741static int dh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
742{
743 int rv = 0;
744
745 X509_ALGOR *alg, *kekalg = NULL;
746 ASN1_OCTET_STRING *ukm;
747 const unsigned char *p;
748 unsigned char *dukm = NULL;
749 size_t dukmlen = 0;
750 int keylen, plen;
751 const EVP_CIPHER *kekcipher;
752 EVP_CIPHER_CTX *kekctx;
753
754 if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
755 goto err;
756
757 /*
758 * For DH we only have one OID permissible. If ever any more get defined
759 * we will need something cleverer.
760 */
761 if (OBJ_obj2nid(alg->algorithm) != NID_id_smime_alg_ESDH) {
762 DHerr(DH_F_DH_CMS_SET_SHARED_INFO, DH_R_KDF_PARAMETER_ERROR);
763 goto err;
764 }
765
766 if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, EVP_PKEY_DH_KDF_X9_42) <= 0)
767 goto err;
768
769 if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, EVP_sha1()) <= 0)
770 goto err;
771
772 if (alg->parameter->type != V_ASN1_SEQUENCE)
773 goto err;
774
775 p = alg->parameter->value.sequence->data;
776 plen = alg->parameter->value.sequence->length;
777 kekalg = d2i_X509_ALGOR(NULL, &p, plen);
778 if (!kekalg)
779 goto err;
780 kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
781 if (!kekctx)
782 goto err;
783 kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
784 if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
785 goto err;
786 if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
787 goto err;
788 if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
789 goto err;
790
791 keylen = EVP_CIPHER_CTX_key_length(kekctx);
792 if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
793 goto err;
794 /* Use OBJ_nid2obj to ensure we use built in OID that isn't freed */
795 if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx,
796 OBJ_nid2obj(EVP_CIPHER_type(kekcipher)))
797 <= 0)
798 goto err;
799
800 if (ukm) {
801 dukmlen = ASN1_STRING_length(ukm);
802 dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
803 if (!dukm)
804 goto err;
805 }
806
807 if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
808 goto err;
809 dukm = NULL;
810
811 rv = 1;
812 err:
813 X509_ALGOR_free(kekalg);
814 OPENSSL_free(dukm);
815 return rv;
816}
817
818static int dh_cms_decrypt(CMS_RecipientInfo *ri)
819{
820 EVP_PKEY_CTX *pctx;
821 pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
822
823 if (pctx == NULL)
824 return 0;
825 /* See if we need to set peer key */
826 if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
827 X509_ALGOR *alg;
828 ASN1_BIT_STRING *pubkey;
829 if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
830 NULL, NULL, NULL))
831 return 0;
832 if (!alg || !pubkey)
833 return 0;
834 if (!dh_cms_set_peerkey(pctx, alg, pubkey)) {
835 DHerr(DH_F_DH_CMS_DECRYPT, DH_R_PEER_KEY_ERROR);
836 return 0;
837 }
838 }
839 /* Set DH derivation parameters and initialise unwrap context */
840 if (!dh_cms_set_shared_info(pctx, ri)) {
841 DHerr(DH_F_DH_CMS_DECRYPT, DH_R_SHARED_INFO_ERROR);
842 return 0;
843 }
844 return 1;
845}
846
847static int dh_cms_encrypt(CMS_RecipientInfo *ri)
848{
849 EVP_PKEY_CTX *pctx;
850 EVP_PKEY *pkey;
851 EVP_CIPHER_CTX *ctx;
852 int keylen;
853 X509_ALGOR *talg, *wrap_alg = NULL;
854 const ASN1_OBJECT *aoid;
855 ASN1_BIT_STRING *pubkey;
856 ASN1_STRING *wrap_str;
857 ASN1_OCTET_STRING *ukm;
858 unsigned char *penc = NULL, *dukm = NULL;
859 int penclen;
860 size_t dukmlen = 0;
861 int rv = 0;
862 int kdf_type, wrap_nid;
863 const EVP_MD *kdf_md;
864
865 pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
866 if (pctx == NULL)
867 return 0;
868 /* Get ephemeral key */
869 pkey = EVP_PKEY_CTX_get0_pkey(pctx);
870 if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
871 NULL, NULL, NULL))
872 goto err;
873 X509_ALGOR_get0(&aoid, NULL, NULL, talg);
874 /* Is everything uninitialised? */
875 if (aoid == OBJ_nid2obj(NID_undef)) {
876 ASN1_INTEGER *pubk = BN_to_ASN1_INTEGER(pkey->pkey.dh->pub_key, NULL);
877
878 if (pubk == NULL)
879 goto err;
880 /* Set the key */
881
882 penclen = i2d_ASN1_INTEGER(pubk, &penc);
883 ASN1_INTEGER_free(pubk);
884 if (penclen <= 0)
885 goto err;
886 ASN1_STRING_set0(pubkey, penc, penclen);
887 pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
888 pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
889
890 penc = NULL;
891 X509_ALGOR_set0(talg, OBJ_nid2obj(NID_dhpublicnumber),
892 V_ASN1_UNDEF, NULL);
893 }
894
895 /* See if custom parameters set */
896 kdf_type = EVP_PKEY_CTX_get_dh_kdf_type(pctx);
897 if (kdf_type <= 0)
898 goto err;
899 if (!EVP_PKEY_CTX_get_dh_kdf_md(pctx, &kdf_md))
900 goto err;
901
902 if (kdf_type == EVP_PKEY_DH_KDF_NONE) {
903 kdf_type = EVP_PKEY_DH_KDF_X9_42;
904 if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, kdf_type) <= 0)
905 goto err;
906 } else if (kdf_type != EVP_PKEY_DH_KDF_X9_42)
907 /* Unknown KDF */
908 goto err;
909 if (kdf_md == NULL) {
910 /* Only SHA1 supported */
911 kdf_md = EVP_sha1();
912 if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, kdf_md) <= 0)
913 goto err;
914 } else if (EVP_MD_type(kdf_md) != NID_sha1)
915 /* Unsupported digest */
916 goto err;
917
918 if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
919 goto err;
920
921 /* Get wrap NID */
922 ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
923 wrap_nid = EVP_CIPHER_CTX_type(ctx);
924 if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx, OBJ_nid2obj(wrap_nid)) <= 0)
925 goto err;
926 keylen = EVP_CIPHER_CTX_key_length(ctx);
927
928 /* Package wrap algorithm in an AlgorithmIdentifier */
929
930 wrap_alg = X509_ALGOR_new();
931 if (wrap_alg == NULL)
932 goto err;
933 wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
934 wrap_alg->parameter = ASN1_TYPE_new();
935 if (wrap_alg->parameter == NULL)
936 goto err;
937 if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
938 goto err;
939 if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
940 ASN1_TYPE_free(wrap_alg->parameter);
941 wrap_alg->parameter = NULL;
942 }
943
944 if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
945 goto err;
946
947 if (ukm) {
948 dukmlen = ASN1_STRING_length(ukm);
949 dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
950 if (!dukm)
951 goto err;
952 }
953
954 if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
955 goto err;
956 dukm = NULL;
957
958 /*
959 * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
960 * of another AlgorithmIdentifier.
961 */
962 penc = NULL;
963 penclen = i2d_X509_ALGOR(wrap_alg, &penc);
964 if (penc == NULL || penclen == 0)
965 goto err;
966 wrap_str = ASN1_STRING_new();
967 if (wrap_str == NULL)
968 goto err;
969 ASN1_STRING_set0(wrap_str, penc, penclen);
970 penc = NULL;
971 X509_ALGOR_set0(talg, OBJ_nid2obj(NID_id_smime_alg_ESDH),
972 V_ASN1_SEQUENCE, wrap_str);
973
974 rv = 1;
975
976 err:
977 OPENSSL_free(penc);
978 X509_ALGOR_free(wrap_alg);
979 OPENSSL_free(dukm);
980 return rv;
981}
982
983#endif
984