crypto/dh/dh_ameth.c

   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 /*
  11  * DH low level APIs are deprecated for public use, but still ok for
  12  * internal use.
  13  */
  14 #include "internal/deprecated.h"
  15
  16 #include <stdio.h>
  17 #include "internal/cryptlib.h"
  18 #include <openssl/x509.h>
  19 #include <openssl/asn1.h>
  20 #include "dh_local.h"
  21 #include <openssl/bn.h>
  22 #include "crypto/asn1.h"
  23 #include "crypto/dh.h"
  24 #include "crypto/evp.h"
  25 #include <openssl/cms.h>
  26 #include <openssl/core_names.h>
  27 #include "openssl/param_build.h"
  28 #include "internal/ffc.h"
  29
  30 /*
  31  * i2d/d2i like DH parameter functions which use the appropriate routine for
  32  * PKCS#3 DH or X9.42 DH.
  33  */
  34
  35 static DH *d2i_dhp(const EVP_PKEY *pkey, const unsigned char **pp,
  36                    long length)
  37 {
  38     if (pkey->ameth == &dhx_asn1_meth)
  39         return d2i_DHxparams(NULL, pp, length);
  40     return d2i_DHparams(NULL, pp, length);
  41 }
  42
  43 static int i2d_dhp(const EVP_PKEY *pkey, const DH *a, unsigned char **pp)
  44 {
  45     if (pkey->ameth == &dhx_asn1_meth)
  46         return i2d_DHxparams(a, pp);
  47     return i2d_DHparams(a, pp);
  48 }
  49
  50 static void int_dh_free(EVP_PKEY *pkey)
  51 {
  52     DH_free(pkey->pkey.dh);
  53 }
  54
  55 static int dh_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
  56 {
  57     const unsigned char *p, *pm;
  58     int pklen, pmlen;
  59     int ptype;
  60     const void *pval;
  61     const ASN1_STRING *pstr;
  62     X509_ALGOR *palg;
  63     ASN1_INTEGER *public_key = NULL;
  64
  65     DH *dh = NULL;
  66
  67     if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
  68         return 0;
  69     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
  70
  71     if (ptype != V_ASN1_SEQUENCE) {
  72         DHerr(DH_F_DH_PUB_DECODE, DH_R_PARAMETER_ENCODING_ERROR);
  73         goto err;
  74     }
  75
  76     pstr = pval;
  77     pm = pstr->data;
  78     pmlen = pstr->length;
  79
  80     if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL) {
  81         DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
  82         goto err;
  83     }
  84
  85     if ((public_key = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL) {
  86         DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
  87         goto err;
  88     }
  89
  90     /* We have parameters now set public key */
  91     if ((dh->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
  92         DHerr(DH_F_DH_PUB_DECODE, DH_R_BN_DECODE_ERROR);
  93         goto err;
  94     }
  95
  96     ASN1_INTEGER_free(public_key);
  97     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
  98     return 1;
  99
 100  err:
 101     ASN1_INTEGER_free(public_key);
 102     DH_free(dh);
 103     return 0;
 104
 105 }
 106
 107 static int dh_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
 108 {
 109     DH *dh;
 110     int ptype;
 111     unsigned char *penc = NULL;
 112     int penclen;
 113     ASN1_STRING *str;
 114     ASN1_INTEGER *pub_key = NULL;
 115
 116     dh = pkey->pkey.dh;
 117
 118     str = ASN1_STRING_new();
 119     if (str == NULL) {
 120         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 121         goto err;
 122     }
 123     str->length = i2d_dhp(pkey, dh, &str->data);
 124     if (str->length <= 0) {
 125         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 126         goto err;
 127     }
 128     ptype = V_ASN1_SEQUENCE;
 129
 130     pub_key = BN_to_ASN1_INTEGER(dh->pub_key, NULL);
 131     if (pub_key == NULL)
 132         goto err;
 133
 134     penclen = i2d_ASN1_INTEGER(pub_key, &penc);
 135
 136     ASN1_INTEGER_free(pub_key);
 137
 138     if (penclen <= 0) {
 139         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 140         goto err;
 141     }
 142
 143     if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
 144                                ptype, str, penc, penclen))
 145         return 1;
 146
 147  err:
 148     OPENSSL_free(penc);
 149     ASN1_STRING_free(str);
 150
 151     return 0;
 152 }
 153
 154 /*
 155  * PKCS#8 DH is defined in PKCS#11 of all places. It is similar to DH in that
 156  * the AlgorithmIdentifier contains the parameters, the private key is
 157  * explicitly included and the pubkey must be recalculated.
 158  */
 159
 160 static int dh_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
 161 {
 162     const unsigned char *p, *pm;
 163     int pklen, pmlen;
 164     int ptype;
 165     const void *pval;
 166     const ASN1_STRING *pstr;
 167     const X509_ALGOR *palg;
 168     ASN1_INTEGER *privkey = NULL;
 169     DH *dh = NULL;
 170
 171     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 172         return 0;
 173
 174     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 175
 176     if (ptype != V_ASN1_SEQUENCE)
 177         goto decerr;
 178     if ((privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL)
 179         goto decerr;
 180
 181     pstr = pval;
 182     pm = pstr->data;
 183     pmlen = pstr->length;
 184     if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL)
 185         goto decerr;
 186
 187     /* We have parameters now set private key */
 188     if ((dh->priv_key = BN_secure_new()) == NULL
 189         || !ASN1_INTEGER_to_BN(privkey, dh->priv_key)) {
 190         DHerr(DH_F_DH_PRIV_DECODE, DH_R_BN_ERROR);
 191         goto dherr;
 192     }
 193     /* Calculate public key, increments dirty_cnt */
 194     if (!DH_generate_key(dh))
 195         goto dherr;
 196
 197     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 198
 199     ASN1_STRING_clear_free(privkey);
 200
 201     return 1;
 202
 203  decerr:
 204     DHerr(DH_F_DH_PRIV_DECODE, EVP_R_DECODE_ERROR);
 205  dherr:
 206     DH_free(dh);
 207     ASN1_STRING_clear_free(privkey);
 208     return 0;
 209 }
 210
 211 static int dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 212 {
 213     ASN1_STRING *params = NULL;
 214     ASN1_INTEGER *prkey = NULL;
 215     unsigned char *dp = NULL;
 216     int dplen;
 217
 218     params = ASN1_STRING_new();
 219
 220     if (params == NULL) {
 221         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 222         goto err;
 223     }
 224
 225     params->length = i2d_dhp(pkey, pkey->pkey.dh, &params->data);
 226     if (params->length <= 0) {
 227         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 228         goto err;
 229     }
 230     params->type = V_ASN1_SEQUENCE;
 231
 232     /* Get private key into integer */
 233     prkey = BN_to_ASN1_INTEGER(pkey->pkey.dh->priv_key, NULL);
 234
 235     if (prkey == NULL) {
 236         DHerr(DH_F_DH_PRIV_ENCODE, DH_R_BN_ERROR);
 237         goto err;
 238     }
 239
 240     dplen = i2d_ASN1_INTEGER(prkey, &dp);
 241
 242     ASN1_STRING_clear_free(prkey);
 243     prkey = NULL;
 244
 245     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
 246                          V_ASN1_SEQUENCE, params, dp, dplen))
 247         goto err;
 248
 249     return 1;
 250
 251  err:
 252     OPENSSL_free(dp);
 253     ASN1_STRING_free(params);
 254     ASN1_STRING_clear_free(prkey);
 255     return 0;
 256 }
 257
 258 static int dh_param_decode(EVP_PKEY *pkey,
 259                            const unsigned char **pder, int derlen)
 260 {
 261     DH *dh;
 262
 263     if ((dh = d2i_dhp(pkey, pder, derlen)) == NULL) {
 264         DHerr(DH_F_DH_PARAM_DECODE, ERR_R_DH_LIB);
 265         return 0;
 266     }
 267     dh->dirty_cnt++;
 268     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 269     return 1;
 270 }
 271
 272 static int dh_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 273 {
 274     return i2d_dhp(pkey, pkey->pkey.dh, pder);
 275 }
 276
 277 static int do_dh_print(BIO *bp, const DH *x, int indent, int ptype)
 278 {
 279     int reason = ERR_R_BUF_LIB;
 280     const char *ktype = NULL;
 281     BIGNUM *priv_key, *pub_key;
 282
 283     if (ptype == 2)
 284         priv_key = x->priv_key;
 285     else
 286         priv_key = NULL;
 287
 288     if (ptype > 0)
 289         pub_key = x->pub_key;
 290     else
 291         pub_key = NULL;
 292
 293     if (x->params.p == NULL || (ptype == 2 && priv_key == NULL)
 294             || (ptype > 0 && pub_key == NULL)) {
 295         reason = ERR_R_PASSED_NULL_PARAMETER;
 296         goto err;
 297     }
 298
 299     if (ptype == 2)
 300         ktype = "DH Private-Key";
 301     else if (ptype == 1)
 302         ktype = "DH Public-Key";
 303     else
 304         ktype = "DH Parameters";
 305
 306     if (!BIO_indent(bp, indent, 128)
 307             || BIO_printf(bp, "%s: (%d bit)\n", ktype, DH_bits(x)) <= 0)
 308         goto err;
 309     indent += 4;
 310
 311     if (!ASN1_bn_print(bp, "private-key:", priv_key, NULL, indent))
 312         goto err;
 313     if (!ASN1_bn_print(bp, "public-key:", pub_key, NULL, indent))
 314         goto err;
 315
 316     if (!ffc_params_print(bp, &x->params, indent))
 317         goto err;
 318
 319     if (x->length != 0) {
 320         if (!BIO_indent(bp, indent, 128)
 321                 || BIO_printf(bp, "recommended-private-length: %d bits\n",
 322                               (int)x->length) <= 0)
 323             goto err;
 324     }
 325
 326     return 1;
 327
 328  err:
 329     DHerr(DH_F_DO_DH_PRINT, reason);
 330     return 0;
 331 }
 332
 333 static int int_dh_size(const EVP_PKEY *pkey)
 334 {
 335     return DH_size(pkey->pkey.dh);
 336 }
 337
 338 static int dh_bits(const EVP_PKEY *pkey)
 339 {
 340     return DH_bits(pkey->pkey.dh);
 341 }
 342
 343 static int dh_security_bits(const EVP_PKEY *pkey)
 344 {
 345     return DH_security_bits(pkey->pkey.dh);
 346 }
 347
 348 static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 349 {
 350     return ffc_params_cmp(&a->pkey.dh->params, &a->pkey.dh->params,
 351                           a->ameth != &dhx_asn1_meth);
 352 }
 353
 354 static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
 355 {
 356     if (is_x942 == -1)
 357         is_x942 = (from->params.q != NULL);
 358     if (!ffc_params_copy(&to->params, &from->params))
 359         return 0;
 360     if (!is_x942)
 361         to->length = from->length;
 362     to->dirty_cnt++;
 363     return 1;
 364 }
 365
 366 DH *DHparams_dup(const DH *dh)
 367 {
 368     DH *ret;
 369     ret = DH_new();
 370     if (ret == NULL)
 371         return NULL;
 372     if (!int_dh_param_copy(ret, dh, -1)) {
 373         DH_free(ret);
 374         return NULL;
 375     }
 376     return ret;
 377 }
 378
 379 static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 380 {
 381     if (to->pkey.dh == NULL) {
 382         to->pkey.dh = DH_new();
 383         if (to->pkey.dh == NULL)
 384             return 0;
 385     }
 386     return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
 387                              from->ameth == &dhx_asn1_meth);
 388 }
 389
 390 static int dh_missing_parameters(const EVP_PKEY *a)
 391 {
 392     return a->pkey.dh == NULL
 393         || a->pkey.dh->params.p == NULL
 394         || a->pkey.dh->params.g == NULL;
 395 }
 396
 397 static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 398 {
 399     if (dh_cmp_parameters(a, b) == 0)
 400         return 0;
 401     if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
 402         return 0;
 403     else
 404         return 1;
 405 }
 406
 407 static int dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 408                           ASN1_PCTX *ctx)
 409 {
 410     return do_dh_print(bp, pkey->pkey.dh, indent, 0);
 411 }
 412
 413 static int dh_public_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 414                            ASN1_PCTX *ctx)
 415 {
 416     return do_dh_print(bp, pkey->pkey.dh, indent, 1);
 417 }
 418
 419 static int dh_private_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 420                             ASN1_PCTX *ctx)
 421 {
 422     return do_dh_print(bp, pkey->pkey.dh, indent, 2);
 423 }
 424
 425 int DHparams_print(BIO *bp, const DH *x)
 426 {
 427     return do_dh_print(bp, x, 4, 0);
 428 }
 429
 430 #ifndef OPENSSL_NO_CMS
 431 static int dh_cms_decrypt(CMS_RecipientInfo *ri);
 432 static int dh_cms_encrypt(CMS_RecipientInfo *ri);
 433 #endif
 434
 435 static int dh_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 436 {
 437     switch (op) {
 438     case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
 439         return dh_buf2key(EVP_PKEY_get0_DH(pkey), arg2, arg1);
 440     case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
 441         return dh_key2buf(EVP_PKEY_get0_DH(pkey), arg2);
 442     default:
 443         return -2;
 444     }
 445 }
 446
 447 static int dhx_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 448 {
 449     switch (op) {
 450 #ifndef OPENSSL_NO_CMS
 451
 452     case ASN1_PKEY_CTRL_CMS_ENVELOPE:
 453         if (arg1 == 1)
 454             return dh_cms_decrypt(arg2);
 455         else if (arg1 == 0)
 456             return dh_cms_encrypt(arg2);
 457         return -2;
 458
 459     case ASN1_PKEY_CTRL_CMS_RI_TYPE:
 460         *(int *)arg2 = CMS_RECIPINFO_AGREE;
 461         return 1;
 462 #endif
 463     default:
 464         return -2;
 465     }
 466
 467 }
 468
 469 static int dh_pkey_public_check(const EVP_PKEY *pkey)
 470 {
 471     DH *dh = pkey->pkey.dh;
 472
 473     if (dh->pub_key == NULL) {
 474         DHerr(DH_F_DH_PKEY_PUBLIC_CHECK, DH_R_MISSING_PUBKEY);
 475         return 0;
 476     }
 477
 478     return DH_check_pub_key_ex(dh, dh->pub_key);
 479 }
 480
 481 static int dh_pkey_param_check(const EVP_PKEY *pkey)
 482 {
 483     DH *dh = pkey->pkey.dh;
 484
 485     return DH_check_ex(dh);
 486 }
 487
 488 static size_t dh_pkey_dirty_cnt(const EVP_PKEY *pkey)
 489 {
 490     return pkey->pkey.dh->dirty_cnt;
 491 }
 492
 493 static int dh_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
 494                              EVP_KEYMGMT *to_keymgmt, OPENSSL_CTX *libctx,
 495                              const char *propq)
 496 {
 497     DH *dh = from->pkey.dh;
 498     OSSL_PARAM_BLD *tmpl;
 499     const BIGNUM *p = DH_get0_p(dh), *g = DH_get0_g(dh), *q = DH_get0_q(dh);
 500     const BIGNUM *pub_key = DH_get0_pub_key(dh);
 501     const BIGNUM *priv_key = DH_get0_priv_key(dh);
 502     OSSL_PARAM *params = NULL;
 503     int selection = 0;
 504     int rv = 0;
 505
 506     /*
 507      * If the DH method is foreign, then we can't be sure of anything, and
 508      * can therefore not export or pretend to export.
 509      */
 510     if (dh_get_method(dh) != DH_OpenSSL())
 511         return 0;
 512
 513     if (p == NULL || g == NULL)
 514         return 0;
 515
 516     tmpl = OSSL_PARAM_BLD_new();
 517     if (tmpl == NULL)
 518         return 0;
 519     if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_P, p)
 520         || !OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_G, g))
 521         goto err;
 522     if (q != NULL) {
 523         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_Q, q))
 524             goto err;
 525     }
 526     selection |= OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS;
 527     if (pub_key != NULL) {
 528         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_PUB_KEY, pub_key))
 529             goto err;
 530         selection |= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
 531     }
 532     if (priv_key != NULL) {
 533         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_PRIV_KEY,
 534                                     priv_key))
 535             goto err;
 536         selection |= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
 537     }
 538
 539     if ((params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL)
 540         goto err;
 541
 542     /* We export, the provider imports */
 543     rv = evp_keymgmt_import(to_keymgmt, to_keydata, selection, params);
 544
 545     OSSL_PARAM_BLD_free_params(params);
 546 err:
 547     OSSL_PARAM_BLD_free(tmpl);
 548     return rv;
 549 }
 550
 551 static int dh_pkey_import_from(const OSSL_PARAM params[], void *key)
 552 {
 553     EVP_PKEY *pkey = key;
 554     DH *dh = DH_new();
 555
 556     if (dh == NULL) {
 557         ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
 558         return 0;
 559     }
 560
 561     if (!ffc_fromdata(dh_get0_params(dh), params)
 562         || !dh_key_fromdata(dh, params)
 563         || !EVP_PKEY_assign_DH(pkey, dh)) {
 564         DH_free(dh);
 565         return 0;
 566     }
 567     return 1;
 568 }
 569
 570 const EVP_PKEY_ASN1_METHOD dh_asn1_meth = {
 571     EVP_PKEY_DH,
 572     EVP_PKEY_DH,
 573     0,
 574
 575     "DH",
 576     "OpenSSL PKCS#3 DH method",
 577
 578     dh_pub_decode,
 579     dh_pub_encode,
 580     dh_pub_cmp,
 581     dh_public_print,
 582
 583     dh_priv_decode,
 584     dh_priv_encode,
 585     dh_private_print,
 586
 587     int_dh_size,
 588     dh_bits,
 589     dh_security_bits,
 590
 591     dh_param_decode,
 592     dh_param_encode,
 593     dh_missing_parameters,
 594     dh_copy_parameters,
 595     dh_cmp_parameters,
 596     dh_param_print,
 597     0,
 598
 599     int_dh_free,
 600     dh_pkey_ctrl,
 601
 602     0, 0, 0, 0, 0,
 603
 604     0,
 605     dh_pkey_public_check,
 606     dh_pkey_param_check,
 607
 608     0, 0, 0, 0,
 609
 610     dh_pkey_dirty_cnt,
 611     dh_pkey_export_to,
 612     dh_pkey_import_from,
 613 };
 614
 615 const EVP_PKEY_ASN1_METHOD dhx_asn1_meth = {
 616     EVP_PKEY_DHX,
 617     EVP_PKEY_DHX,
 618     0,
 619
 620     "X9.42 DH",
 621     "OpenSSL X9.42 DH method",
 622
 623     dh_pub_decode,
 624     dh_pub_encode,
 625     dh_pub_cmp,
 626     dh_public_print,
 627
 628     dh_priv_decode,
 629     dh_priv_encode,
 630     dh_private_print,
 631
 632     int_dh_size,
 633     dh_bits,
 634     dh_security_bits,
 635
 636     dh_param_decode,
 637     dh_param_encode,
 638     dh_missing_parameters,
 639     dh_copy_parameters,
 640     dh_cmp_parameters,
 641     dh_param_print,
 642     0,
 643
 644     int_dh_free,
 645     dhx_pkey_ctrl,
 646
 647     0, 0, 0, 0, 0,
 648
 649     0,
 650     dh_pkey_public_check,
 651     dh_pkey_param_check
 652 };
 653
 654 #ifndef OPENSSL_NO_CMS
 655
 656 static int dh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
 657                               X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 658 {
 659     const ASN1_OBJECT *aoid;
 660     int atype;
 661     const void *aval;
 662     ASN1_INTEGER *public_key = NULL;
 663     int rv = 0;
 664     EVP_PKEY *pkpeer = NULL, *pk = NULL;
 665     DH *dhpeer = NULL;
 666     const unsigned char *p;
 667     int plen;
 668
 669     X509_ALGOR_get0(&aoid, &atype, &aval, alg);
 670     if (OBJ_obj2nid(aoid) != NID_dhpublicnumber)
 671         goto err;
 672     /* Only absent parameters allowed in RFC XXXX */
 673     if (atype != V_ASN1_UNDEF && atype == V_ASN1_NULL)
 674         goto err;
 675
 676     pk = EVP_PKEY_CTX_get0_pkey(pctx);
 677     if (pk == NULL)
 678         goto err;
 679     if (pk->type != EVP_PKEY_DHX)
 680         goto err;
 681     /* Get parameters from parent key */
 682     dhpeer = DHparams_dup(pk->pkey.dh);
 683     /* We have parameters now set public key */
 684     plen = ASN1_STRING_length(pubkey);
 685     p = ASN1_STRING_get0_data(pubkey);
 686     if (p == NULL || plen == 0)
 687         goto err;
 688
 689     if ((public_key = d2i_ASN1_INTEGER(NULL, &p, plen)) == NULL) {
 690         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_DECODE_ERROR);
 691         goto err;
 692     }
 693
 694     /* We have parameters now set public key */
 695     if ((dhpeer->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
 696         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_BN_DECODE_ERROR);
 697         goto err;
 698     }
 699
 700     pkpeer = EVP_PKEY_new();
 701     if (pkpeer == NULL)
 702         goto err;
 703     EVP_PKEY_assign(pkpeer, pk->ameth->pkey_id, dhpeer);
 704     dhpeer = NULL;
 705     if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
 706         rv = 1;
 707  err:
 708     ASN1_INTEGER_free(public_key);
 709     EVP_PKEY_free(pkpeer);
 710     DH_free(dhpeer);
 711     return rv;
 712 }
 713
 714 static int dh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 715 {
 716     int rv = 0;
 717
 718     X509_ALGOR *alg, *kekalg = NULL;
 719     ASN1_OCTET_STRING *ukm;
 720     const unsigned char *p;
 721     unsigned char *dukm = NULL;
 722     size_t dukmlen = 0;
 723     int keylen, plen;
 724     const EVP_CIPHER *kekcipher;
 725     EVP_CIPHER_CTX *kekctx;
 726
 727     if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
 728         goto err;
 729
 730     /*
 731      * For DH we only have one OID permissible. If ever any more get defined
 732      * we will need something cleverer.
 733      */
 734     if (OBJ_obj2nid(alg->algorithm) != NID_id_smime_alg_ESDH) {
 735         DHerr(DH_F_DH_CMS_SET_SHARED_INFO, DH_R_KDF_PARAMETER_ERROR);
 736         goto err;
 737     }
 738
 739     if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, EVP_PKEY_DH_KDF_X9_42) <= 0)
 740         goto err;
 741
 742     if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, EVP_sha1()) <= 0)
 743         goto err;
 744
 745     if (alg->parameter->type != V_ASN1_SEQUENCE)
 746         goto err;
 747
 748     p = alg->parameter->value.sequence->data;
 749     plen = alg->parameter->value.sequence->length;
 750     kekalg = d2i_X509_ALGOR(NULL, &p, plen);
 751     if (!kekalg)
 752         goto err;
 753     kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 754     if (!kekctx)
 755         goto err;
 756     kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
 757     if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
 758         goto err;
 759     if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
 760         goto err;
 761     if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
 762         goto err;
 763
 764     keylen = EVP_CIPHER_CTX_key_length(kekctx);
 765     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 766         goto err;
 767     /* Use OBJ_nid2obj to ensure we use built in OID that isn't freed */
 768     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx,
 769                                      OBJ_nid2obj(EVP_CIPHER_type(kekcipher)))
 770         <= 0)
 771         goto err;
 772
 773     if (ukm) {
 774         dukmlen = ASN1_STRING_length(ukm);
 775         dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
 776         if (!dukm)
 777             goto err;
 778     }
 779
 780     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 781         goto err;
 782     dukm = NULL;
 783
 784     rv = 1;
 785  err:
 786     X509_ALGOR_free(kekalg);
 787     OPENSSL_free(dukm);
 788     return rv;
 789 }
 790
 791 static int dh_cms_decrypt(CMS_RecipientInfo *ri)
 792 {
 793     EVP_PKEY_CTX *pctx;
 794
 795     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 796
 797     if (pctx == NULL)
 798         return 0;
 799     /* See if we need to set peer key */
 800     if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
 801         X509_ALGOR *alg;
 802         ASN1_BIT_STRING *pubkey;
 803         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
 804                                                  NULL, NULL, NULL))
 805             return 0;
 806         if (!alg || !pubkey)
 807             return 0;
 808         if (!dh_cms_set_peerkey(pctx, alg, pubkey)) {
 809             DHerr(DH_F_DH_CMS_DECRYPT, DH_R_PEER_KEY_ERROR);
 810             return 0;
 811         }
 812     }
 813     /* Set DH derivation parameters and initialise unwrap context */
 814     if (!dh_cms_set_shared_info(pctx, ri)) {
 815         DHerr(DH_F_DH_CMS_DECRYPT, DH_R_SHARED_INFO_ERROR);
 816         return 0;
 817     }
 818     return 1;
 819 }
 820
 821 static int dh_cms_encrypt(CMS_RecipientInfo *ri)
 822 {
 823     EVP_PKEY_CTX *pctx;
 824     EVP_PKEY *pkey;
 825     EVP_CIPHER_CTX *ctx;
 826     int keylen;
 827     X509_ALGOR *talg, *wrap_alg = NULL;
 828     const ASN1_OBJECT *aoid;
 829     ASN1_BIT_STRING *pubkey;
 830     ASN1_STRING *wrap_str;
 831     ASN1_OCTET_STRING *ukm;
 832     unsigned char *penc = NULL, *dukm = NULL;
 833     int penclen;
 834     size_t dukmlen = 0;
 835     int rv = 0;
 836     int kdf_type, wrap_nid;
 837     const EVP_MD *kdf_md;
 838
 839     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 840     if (pctx == NULL)
 841         return 0;
 842     /* Get ephemeral key */
 843     pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 844     if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
 845                                              NULL, NULL, NULL))
 846         goto err;
 847     X509_ALGOR_get0(&aoid, NULL, NULL, talg);
 848     /* Is everything uninitialised? */
 849     if (aoid == OBJ_nid2obj(NID_undef)) {
 850         ASN1_INTEGER *pubk = BN_to_ASN1_INTEGER(pkey->pkey.dh->pub_key, NULL);
 851
 852         if (pubk == NULL)
 853             goto err;
 854         /* Set the key */
 855
 856         penclen = i2d_ASN1_INTEGER(pubk, &penc);
 857         ASN1_INTEGER_free(pubk);
 858         if (penclen <= 0)
 859             goto err;
 860         ASN1_STRING_set0(pubkey, penc, penclen);
 861         pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 862         pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 863
 864         penc = NULL;
 865         X509_ALGOR_set0(talg, OBJ_nid2obj(NID_dhpublicnumber),
 866                         V_ASN1_UNDEF, NULL);
 867     }
 868
 869     /* See if custom parameters set */
 870     kdf_type = EVP_PKEY_CTX_get_dh_kdf_type(pctx);
 871     if (kdf_type <= 0)
 872         goto err;
 873     if (!EVP_PKEY_CTX_get_dh_kdf_md(pctx, &kdf_md))
 874         goto err;
 875
 876     if (kdf_type == EVP_PKEY_DH_KDF_NONE) {
 877         kdf_type = EVP_PKEY_DH_KDF_X9_42;
 878         if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, kdf_type) <= 0)
 879             goto err;
 880     } else if (kdf_type != EVP_PKEY_DH_KDF_X9_42)
 881         /* Unknown KDF */
 882         goto err;
 883     if (kdf_md == NULL) {
 884         /* Only SHA1 supported */
 885         kdf_md = EVP_sha1();
 886         if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, kdf_md) <= 0)
 887             goto err;
 888     } else if (EVP_MD_type(kdf_md) != NID_sha1)
 889         /* Unsupported digest */
 890         goto err;
 891
 892     if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
 893         goto err;
 894
 895     /* Get wrap NID */
 896     ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 897     wrap_nid = EVP_CIPHER_CTX_type(ctx);
 898     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx, OBJ_nid2obj(wrap_nid)) <= 0)
 899         goto err;
 900     keylen = EVP_CIPHER_CTX_key_length(ctx);
 901
 902     /* Package wrap algorithm in an AlgorithmIdentifier */
 903
 904     wrap_alg = X509_ALGOR_new();
 905     if (wrap_alg == NULL)
 906         goto err;
 907     wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
 908     wrap_alg->parameter = ASN1_TYPE_new();
 909     if (wrap_alg->parameter == NULL)
 910         goto err;
 911     if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
 912         goto err;
 913     if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
 914         ASN1_TYPE_free(wrap_alg->parameter);
 915         wrap_alg->parameter = NULL;
 916     }
 917
 918     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 919         goto err;
 920
 921     if (ukm) {
 922         dukmlen = ASN1_STRING_length(ukm);
 923         dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
 924         if (!dukm)
 925             goto err;
 926     }
 927
 928     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 929         goto err;
 930     dukm = NULL;
 931
 932     /*
 933      * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
 934      * of another AlgorithmIdentifier.
 935      */
 936     penc = NULL;
 937     penclen = i2d_X509_ALGOR(wrap_alg, &penc);
 938     if (penc == NULL || penclen == 0)
 939         goto err;
 940     wrap_str = ASN1_STRING_new();
 941     if (wrap_str == NULL)
 942         goto err;
 943     ASN1_STRING_set0(wrap_str, penc, penclen);
 944     penc = NULL;
 945     X509_ALGOR_set0(talg, OBJ_nid2obj(NID_id_smime_alg_ESDH),
 946                     V_ASN1_SEQUENCE, wrap_str);
 947
 948     rv = 1;
 949
 950  err:
 951     OPENSSL_free(penc);
 952     X509_ALGOR_free(wrap_alg);
 953     OPENSSL_free(dukm);
 954     return rv;
 955 }
 956
 957 #endif