crypto/dh/dh_ameth.c

   1 /*
   2  * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
   3  * 2006.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 2006 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    licensing@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58
  59 #include <stdio.h>
  60 #include "cryptlib.h"
  61 #include <openssl/x509.h>
  62 #include <openssl/asn1.h>
  63 #include <openssl/dh.h>
  64 #include <openssl/bn.h>
  65 #include "internal/asn1_int.h"
  66 #ifndef OPENSSL_NO_CMS
  67 # include <openssl/cms.h>
  68 #endif
  69
  70 extern const EVP_PKEY_ASN1_METHOD dhx_asn1_meth;
  71
  72 /*
  73  * i2d/d2i like DH parameter functions which use the appropriate routine for
  74  * PKCS#3 DH or X9.42 DH.
  75  */
  76
  77 static DH *d2i_dhp(const EVP_PKEY *pkey, const unsigned char **pp,
  78                    long length)
  79 {
  80     if (pkey->ameth == &dhx_asn1_meth)
  81         return d2i_DHxparams(NULL, pp, length);
  82     return d2i_DHparams(NULL, pp, length);
  83 }
  84
  85 static int i2d_dhp(const EVP_PKEY *pkey, const DH *a, unsigned char **pp)
  86 {
  87     if (pkey->ameth == &dhx_asn1_meth)
  88         return i2d_DHxparams(a, pp);
  89     return i2d_DHparams(a, pp);
  90 }
  91
  92 static void int_dh_free(EVP_PKEY *pkey)
  93 {
  94     DH_free(pkey->pkey.dh);
  95 }
  96
  97 static int dh_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
  98 {
  99     const unsigned char *p, *pm;
 100     int pklen, pmlen;
 101     int ptype;
 102     void *pval;
 103     ASN1_STRING *pstr;
 104     X509_ALGOR *palg;
 105     ASN1_INTEGER *public_key = NULL;
 106
 107     DH *dh = NULL;
 108
 109     if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
 110         return 0;
 111     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 112
 113     if (ptype != V_ASN1_SEQUENCE) {
 114         DHerr(DH_F_DH_PUB_DECODE, DH_R_PARAMETER_ENCODING_ERROR);
 115         goto err;
 116     }
 117
 118     pstr = pval;
 119     pm = pstr->data;
 120     pmlen = pstr->length;
 121
 122     if (!(dh = d2i_dhp(pkey, &pm, pmlen))) {
 123         DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
 124         goto err;
 125     }
 126
 127     if (!(public_key = d2i_ASN1_INTEGER(NULL, &p, pklen))) {
 128         DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
 129         goto err;
 130     }
 131
 132     /* We have parameters now set public key */
 133     if (!(dh->pub_key = ASN1_INTEGER_to_BN(public_key, NULL))) {
 134         DHerr(DH_F_DH_PUB_DECODE, DH_R_BN_DECODE_ERROR);
 135         goto err;
 136     }
 137
 138     ASN1_INTEGER_free(public_key);
 139     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 140     return 1;
 141
 142  err:
 143     ASN1_INTEGER_free(public_key);
 144     DH_free(dh);
 145     return 0;
 146
 147 }
 148
 149 static int dh_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
 150 {
 151     DH *dh;
 152     int ptype;
 153     unsigned char *penc = NULL;
 154     int penclen;
 155     ASN1_STRING *str;
 156     ASN1_INTEGER *pub_key = NULL;
 157
 158     dh = pkey->pkey.dh;
 159
 160     str = ASN1_STRING_new();
 161     if (!str) {
 162         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 163         goto err;
 164     }
 165     str->length = i2d_dhp(pkey, dh, &str->data);
 166     if (str->length <= 0) {
 167         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 168         goto err;
 169     }
 170     ptype = V_ASN1_SEQUENCE;
 171
 172     pub_key = BN_to_ASN1_INTEGER(dh->pub_key, NULL);
 173     if (!pub_key)
 174         goto err;
 175
 176     penclen = i2d_ASN1_INTEGER(pub_key, &penc);
 177
 178     ASN1_INTEGER_free(pub_key);
 179
 180     if (penclen <= 0) {
 181         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 182         goto err;
 183     }
 184
 185     if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
 186                                ptype, str, penc, penclen))
 187         return 1;
 188
 189  err:
 190     OPENSSL_free(penc);
 191     ASN1_STRING_free(str);
 192
 193     return 0;
 194 }
 195
 196 /*
 197  * PKCS#8 DH is defined in PKCS#11 of all places. It is similar to DH in that
 198  * the AlgorithmIdentifier contains the parameters, the private key is
 199  * explcitly included and the pubkey must be recalculated.
 200  */
 201
 202 static int dh_priv_decode(EVP_PKEY *pkey, PKCS8_PRIV_KEY_INFO *p8)
 203 {
 204     const unsigned char *p, *pm;
 205     int pklen, pmlen;
 206     int ptype;
 207     void *pval;
 208     ASN1_STRING *pstr;
 209     X509_ALGOR *palg;
 210     ASN1_INTEGER *privkey = NULL;
 211
 212     DH *dh = NULL;
 213
 214     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 215         return 0;
 216
 217     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 218
 219     if (ptype != V_ASN1_SEQUENCE)
 220         goto decerr;
 221
 222     if (!(privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)))
 223         goto decerr;
 224
 225     pstr = pval;
 226     pm = pstr->data;
 227     pmlen = pstr->length;
 228     if (!(dh = d2i_dhp(pkey, &pm, pmlen)))
 229         goto decerr;
 230     /* We have parameters now set private key */
 231     if (!(dh->priv_key = ASN1_INTEGER_to_BN(privkey, NULL))) {
 232         DHerr(DH_F_DH_PRIV_DECODE, DH_R_BN_ERROR);
 233         goto dherr;
 234     }
 235     /* Calculate public key */
 236     if (!DH_generate_key(dh))
 237         goto dherr;
 238
 239     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 240
 241     ASN1_STRING_clear_free(privkey);
 242
 243     return 1;
 244
 245  decerr:
 246     DHerr(DH_F_DH_PRIV_DECODE, EVP_R_DECODE_ERROR);
 247  dherr:
 248     DH_free(dh);
 249     ASN1_STRING_clear_free(privkey);
 250     return 0;
 251 }
 252
 253 static int dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 254 {
 255     ASN1_STRING *params = NULL;
 256     ASN1_INTEGER *prkey = NULL;
 257     unsigned char *dp = NULL;
 258     int dplen;
 259
 260     params = ASN1_STRING_new();
 261
 262     if (!params) {
 263         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 264         goto err;
 265     }
 266
 267     params->length = i2d_dhp(pkey, pkey->pkey.dh, &params->data);
 268     if (params->length <= 0) {
 269         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 270         goto err;
 271     }
 272     params->type = V_ASN1_SEQUENCE;
 273
 274     /* Get private key into integer */
 275     prkey = BN_to_ASN1_INTEGER(pkey->pkey.dh->priv_key, NULL);
 276
 277     if (!prkey) {
 278         DHerr(DH_F_DH_PRIV_ENCODE, DH_R_BN_ERROR);
 279         goto err;
 280     }
 281
 282     dplen = i2d_ASN1_INTEGER(prkey, &dp);
 283
 284     ASN1_STRING_clear_free(prkey);
 285     prkey = NULL;
 286
 287     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
 288                          V_ASN1_SEQUENCE, params, dp, dplen))
 289         goto err;
 290
 291     return 1;
 292
 293  err:
 294     OPENSSL_free(dp);
 295     ASN1_STRING_free(params);
 296     ASN1_STRING_clear_free(prkey);
 297     return 0;
 298 }
 299
 300 static void update_buflen(const BIGNUM *b, size_t *pbuflen)
 301 {
 302     size_t i;
 303     if (!b)
 304         return;
 305     if (*pbuflen < (i = (size_t)BN_num_bytes(b)))
 306         *pbuflen = i;
 307 }
 308
 309 static int dh_param_decode(EVP_PKEY *pkey,
 310                            const unsigned char **pder, int derlen)
 311 {
 312     DH *dh;
 313     if (!(dh = d2i_dhp(pkey, pder, derlen))) {
 314         DHerr(DH_F_DH_PARAM_DECODE, ERR_R_DH_LIB);
 315         return 0;
 316     }
 317     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 318     return 1;
 319 }
 320
 321 static int dh_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 322 {
 323     return i2d_dhp(pkey, pkey->pkey.dh, pder);
 324 }
 325
 326 static int do_dh_print(BIO *bp, const DH *x, int indent,
 327                        ASN1_PCTX *ctx, int ptype)
 328 {
 329     unsigned char *m = NULL;
 330     int reason = ERR_R_BUF_LIB, ret = 0;
 331     size_t buf_len = 0;
 332
 333     const char *ktype = NULL;
 334
 335     BIGNUM *priv_key, *pub_key;
 336
 337     if (ptype == 2)
 338         priv_key = x->priv_key;
 339     else
 340         priv_key = NULL;
 341
 342     if (ptype > 0)
 343         pub_key = x->pub_key;
 344     else
 345         pub_key = NULL;
 346
 347     update_buflen(x->p, &buf_len);
 348
 349     if (buf_len == 0) {
 350         reason = ERR_R_PASSED_NULL_PARAMETER;
 351         goto err;
 352     }
 353
 354     update_buflen(x->g, &buf_len);
 355     update_buflen(x->q, &buf_len);
 356     update_buflen(x->j, &buf_len);
 357     update_buflen(x->counter, &buf_len);
 358     update_buflen(pub_key, &buf_len);
 359     update_buflen(priv_key, &buf_len);
 360
 361     if (ptype == 2)
 362         ktype = "DH Private-Key";
 363     else if (ptype == 1)
 364         ktype = "DH Public-Key";
 365     else
 366         ktype = "DH Parameters";
 367
 368     m = OPENSSL_malloc(buf_len + 10);
 369     if (m == NULL) {
 370         reason = ERR_R_MALLOC_FAILURE;
 371         goto err;
 372     }
 373
 374     BIO_indent(bp, indent, 128);
 375     if (BIO_printf(bp, "%s: (%d bit)\n", ktype, BN_num_bits(x->p)) <= 0)
 376         goto err;
 377     indent += 4;
 378
 379     if (!ASN1_bn_print(bp, "private-key:", priv_key, m, indent))
 380         goto err;
 381     if (!ASN1_bn_print(bp, "public-key:", pub_key, m, indent))
 382         goto err;
 383
 384     if (!ASN1_bn_print(bp, "prime:", x->p, m, indent))
 385         goto err;
 386     if (!ASN1_bn_print(bp, "generator:", x->g, m, indent))
 387         goto err;
 388     if (x->q && !ASN1_bn_print(bp, "subgroup order:", x->q, m, indent))
 389         goto err;
 390     if (x->j && !ASN1_bn_print(bp, "subgroup factor:", x->j, m, indent))
 391         goto err;
 392     if (x->seed) {
 393         int i;
 394         BIO_indent(bp, indent, 128);
 395         BIO_puts(bp, "seed:");
 396         for (i = 0; i < x->seedlen; i++) {
 397             if ((i % 15) == 0) {
 398                 if (BIO_puts(bp, "\n") <= 0
 399                     || !BIO_indent(bp, indent + 4, 128))
 400                     goto err;
 401             }
 402             if (BIO_printf(bp, "%02x%s", x->seed[i],
 403                            ((i + 1) == x->seedlen) ? "" : ":") <= 0)
 404                 goto err;
 405         }
 406         if (BIO_write(bp, "\n", 1) <= 0)
 407             return (0);
 408     }
 409     if (x->counter && !ASN1_bn_print(bp, "counter:", x->counter, m, indent))
 410         goto err;
 411     if (x->length != 0) {
 412         BIO_indent(bp, indent, 128);
 413         if (BIO_printf(bp, "recommended-private-length: %d bits\n",
 414                        (int)x->length) <= 0)
 415             goto err;
 416     }
 417
 418     ret = 1;
 419     if (0) {
 420  err:
 421         DHerr(DH_F_DO_DH_PRINT, reason);
 422     }
 423     OPENSSL_free(m);
 424     return (ret);
 425 }
 426
 427 static int int_dh_size(const EVP_PKEY *pkey)
 428 {
 429     return (DH_size(pkey->pkey.dh));
 430 }
 431
 432 static int dh_bits(const EVP_PKEY *pkey)
 433 {
 434     return BN_num_bits(pkey->pkey.dh->p);
 435 }
 436
 437 static int dh_security_bits(const EVP_PKEY *pkey)
 438 {
 439     return DH_security_bits(pkey->pkey.dh);
 440 }
 441
 442 static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 443 {
 444     if (BN_cmp(a->pkey.dh->p, b->pkey.dh->p) ||
 445         BN_cmp(a->pkey.dh->g, b->pkey.dh->g))
 446         return 0;
 447     else if (a->ameth == &dhx_asn1_meth) {
 448         if (BN_cmp(a->pkey.dh->q, b->pkey.dh->q))
 449             return 0;
 450     }
 451     return 1;
 452 }
 453
 454 static int int_dh_bn_cpy(BIGNUM **dst, const BIGNUM *src)
 455 {
 456     BIGNUM *a;
 457     if (src) {
 458         a = BN_dup(src);
 459         if (!a)
 460             return 0;
 461     } else
 462         a = NULL;
 463     BN_free(*dst);
 464     *dst = a;
 465     return 1;
 466 }
 467
 468 static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
 469 {
 470     if (is_x942 == -1)
 471         is_x942 = ! !from->q;
 472     if (!int_dh_bn_cpy(&to->p, from->p))
 473         return 0;
 474     if (!int_dh_bn_cpy(&to->g, from->g))
 475         return 0;
 476     if (is_x942) {
 477         if (!int_dh_bn_cpy(&to->q, from->q))
 478             return 0;
 479         if (!int_dh_bn_cpy(&to->j, from->j))
 480             return 0;
 481         OPENSSL_free(to->seed);
 482         to->seed = NULL;
 483         to->seedlen = 0;
 484         if (from->seed) {
 485             to->seed = BUF_memdup(from->seed, from->seedlen);
 486             if (!to->seed)
 487                 return 0;
 488             to->seedlen = from->seedlen;
 489         }
 490     } else
 491         to->length = from->length;
 492     return 1;
 493 }
 494
 495 DH *DHparams_dup(DH *dh)
 496 {
 497     DH *ret;
 498     ret = DH_new();
 499     if (!ret)
 500         return NULL;
 501     if (!int_dh_param_copy(ret, dh, -1)) {
 502         DH_free(ret);
 503         return NULL;
 504     }
 505     return ret;
 506 }
 507
 508 static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 509 {
 510     return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
 511                              from->ameth == &dhx_asn1_meth);
 512 }
 513
 514 static int dh_missing_parameters(const EVP_PKEY *a)
 515 {
 516     if (!a->pkey.dh->p || !a->pkey.dh->g)
 517         return 1;
 518     return 0;
 519 }
 520
 521 static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 522 {
 523     if (dh_cmp_parameters(a, b) == 0)
 524         return 0;
 525     if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
 526         return 0;
 527     else
 528         return 1;
 529 }
 530
 531 static int dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 532                           ASN1_PCTX *ctx)
 533 {
 534     return do_dh_print(bp, pkey->pkey.dh, indent, ctx, 0);
 535 }
 536
 537 static int dh_public_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 538                            ASN1_PCTX *ctx)
 539 {
 540     return do_dh_print(bp, pkey->pkey.dh, indent, ctx, 1);
 541 }
 542
 543 static int dh_private_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 544                             ASN1_PCTX *ctx)
 545 {
 546     return do_dh_print(bp, pkey->pkey.dh, indent, ctx, 2);
 547 }
 548
 549 int DHparams_print(BIO *bp, const DH *x)
 550 {
 551     return do_dh_print(bp, x, 4, NULL, 0);
 552 }
 553
 554 #ifndef OPENSSL_NO_CMS
 555 static int dh_cms_decrypt(CMS_RecipientInfo *ri);
 556 static int dh_cms_encrypt(CMS_RecipientInfo *ri);
 557 #endif
 558
 559 static int dh_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 560 {
 561     switch (op) {
 562 #ifndef OPENSSL_NO_CMS
 563
 564     case ASN1_PKEY_CTRL_CMS_ENVELOPE:
 565         if (arg1 == 1)
 566             return dh_cms_decrypt(arg2);
 567         else if (arg1 == 0)
 568             return dh_cms_encrypt(arg2);
 569         return -2;
 570
 571     case ASN1_PKEY_CTRL_CMS_RI_TYPE:
 572         *(int *)arg2 = CMS_RECIPINFO_AGREE;
 573         return 1;
 574 #endif
 575     default:
 576         return -2;
 577     }
 578
 579 }
 580
 581 const EVP_PKEY_ASN1_METHOD dh_asn1_meth = {
 582     EVP_PKEY_DH,
 583     EVP_PKEY_DH,
 584     0,
 585
 586     "DH",
 587     "OpenSSL PKCS#3 DH method",
 588
 589     dh_pub_decode,
 590     dh_pub_encode,
 591     dh_pub_cmp,
 592     dh_public_print,
 593
 594     dh_priv_decode,
 595     dh_priv_encode,
 596     dh_private_print,
 597
 598     int_dh_size,
 599     dh_bits,
 600     dh_security_bits,
 601
 602     dh_param_decode,
 603     dh_param_encode,
 604     dh_missing_parameters,
 605     dh_copy_parameters,
 606     dh_cmp_parameters,
 607     dh_param_print,
 608     0,
 609
 610     int_dh_free,
 611     0
 612 };
 613
 614 const EVP_PKEY_ASN1_METHOD dhx_asn1_meth = {
 615     EVP_PKEY_DHX,
 616     EVP_PKEY_DHX,
 617     0,
 618
 619     "X9.42 DH",
 620     "OpenSSL X9.42 DH method",
 621
 622     dh_pub_decode,
 623     dh_pub_encode,
 624     dh_pub_cmp,
 625     dh_public_print,
 626
 627     dh_priv_decode,
 628     dh_priv_encode,
 629     dh_private_print,
 630
 631     int_dh_size,
 632     dh_bits,
 633     dh_security_bits,
 634
 635     dh_param_decode,
 636     dh_param_encode,
 637     dh_missing_parameters,
 638     dh_copy_parameters,
 639     dh_cmp_parameters,
 640     dh_param_print,
 641     0,
 642
 643     int_dh_free,
 644     dh_pkey_ctrl
 645 };
 646
 647 #ifndef OPENSSL_NO_CMS
 648
 649 static int dh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
 650                               X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 651 {
 652     ASN1_OBJECT *aoid;
 653     int atype;
 654     void *aval;
 655     ASN1_INTEGER *public_key = NULL;
 656     int rv = 0;
 657     EVP_PKEY *pkpeer = NULL, *pk = NULL;
 658     DH *dhpeer = NULL;
 659     const unsigned char *p;
 660     int plen;
 661
 662     X509_ALGOR_get0(&aoid, &atype, &aval, alg);
 663     if (OBJ_obj2nid(aoid) != NID_dhpublicnumber)
 664         goto err;
 665     /* Only absent parameters allowed in RFC XXXX */
 666     if (atype != V_ASN1_UNDEF && atype == V_ASN1_NULL)
 667         goto err;
 668
 669     pk = EVP_PKEY_CTX_get0_pkey(pctx);
 670     if (!pk)
 671         goto err;
 672     if (pk->type != EVP_PKEY_DHX)
 673         goto err;
 674     /* Get parameters from parent key */
 675     dhpeer = DHparams_dup(pk->pkey.dh);
 676     /* We have parameters now set public key */
 677     plen = ASN1_STRING_length(pubkey);
 678     p = ASN1_STRING_data(pubkey);
 679     if (!p || !plen)
 680         goto err;
 681
 682     if (!(public_key = d2i_ASN1_INTEGER(NULL, &p, plen))) {
 683         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_DECODE_ERROR);
 684         goto err;
 685     }
 686
 687     /* We have parameters now set public key */
 688     if (!(dhpeer->pub_key = ASN1_INTEGER_to_BN(public_key, NULL))) {
 689         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_BN_DECODE_ERROR);
 690         goto err;
 691     }
 692
 693     pkpeer = EVP_PKEY_new();
 694     if (!pkpeer)
 695         goto err;
 696     EVP_PKEY_assign(pkpeer, pk->ameth->pkey_id, dhpeer);
 697     dhpeer = NULL;
 698     if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
 699         rv = 1;
 700  err:
 701     ASN1_INTEGER_free(public_key);
 702     EVP_PKEY_free(pkpeer);
 703     DH_free(dhpeer);
 704     return rv;
 705 }
 706
 707 static int dh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 708 {
 709     int rv = 0;
 710
 711     X509_ALGOR *alg, *kekalg = NULL;
 712     ASN1_OCTET_STRING *ukm;
 713     const unsigned char *p;
 714     unsigned char *dukm = NULL;
 715     size_t dukmlen = 0;
 716     int keylen, plen;
 717     const EVP_CIPHER *kekcipher;
 718     EVP_CIPHER_CTX *kekctx;
 719
 720     if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
 721         goto err;
 722
 723     /*
 724      * For DH we only have one OID permissible. If ever any more get defined
 725      * we will need something cleverer.
 726      */
 727     if (OBJ_obj2nid(alg->algorithm) != NID_id_smime_alg_ESDH) {
 728         DHerr(DH_F_DH_CMS_SET_SHARED_INFO, DH_R_KDF_PARAMETER_ERROR);
 729         goto err;
 730     }
 731
 732     if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, EVP_PKEY_DH_KDF_X9_42) <= 0)
 733         goto err;
 734
 735     if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, EVP_sha1()) <= 0)
 736         goto err;
 737
 738     if (alg->parameter->type != V_ASN1_SEQUENCE)
 739         goto err;
 740
 741     p = alg->parameter->value.sequence->data;
 742     plen = alg->parameter->value.sequence->length;
 743     kekalg = d2i_X509_ALGOR(NULL, &p, plen);
 744     if (!kekalg)
 745         goto err;
 746     kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 747     if (!kekctx)
 748         goto err;
 749     kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
 750     if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
 751         goto err;
 752     if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
 753         goto err;
 754     if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
 755         goto err;
 756
 757     keylen = EVP_CIPHER_CTX_key_length(kekctx);
 758     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 759         goto err;
 760     /* Use OBJ_nid2obj to ensure we use built in OID that isn't freed */
 761     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx,
 762                                      OBJ_nid2obj(EVP_CIPHER_type(kekcipher)))
 763         <= 0)
 764         goto err;
 765
 766     if (ukm) {
 767         dukmlen = ASN1_STRING_length(ukm);
 768         dukm = BUF_memdup(ASN1_STRING_data(ukm), dukmlen);
 769         if (!dukm)
 770             goto err;
 771     }
 772
 773     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 774         goto err;
 775     dukm = NULL;
 776
 777     rv = 1;
 778  err:
 779     X509_ALGOR_free(kekalg);
 780     OPENSSL_free(dukm);
 781     return rv;
 782 }
 783
 784 static int dh_cms_decrypt(CMS_RecipientInfo *ri)
 785 {
 786     EVP_PKEY_CTX *pctx;
 787     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 788     if (!pctx)
 789         return 0;
 790     /* See if we need to set peer key */
 791     if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
 792         X509_ALGOR *alg;
 793         ASN1_BIT_STRING *pubkey;
 794         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
 795                                                  NULL, NULL, NULL))
 796             return 0;
 797         if (!alg || !pubkey)
 798             return 0;
 799         if (!dh_cms_set_peerkey(pctx, alg, pubkey)) {
 800             DHerr(DH_F_DH_CMS_DECRYPT, DH_R_PEER_KEY_ERROR);
 801             return 0;
 802         }
 803     }
 804     /* Set DH derivation parameters and initialise unwrap context */
 805     if (!dh_cms_set_shared_info(pctx, ri)) {
 806         DHerr(DH_F_DH_CMS_DECRYPT, DH_R_SHARED_INFO_ERROR);
 807         return 0;
 808     }
 809     return 1;
 810 }
 811
 812 static int dh_cms_encrypt(CMS_RecipientInfo *ri)
 813 {
 814     EVP_PKEY_CTX *pctx;
 815     EVP_PKEY *pkey;
 816     EVP_CIPHER_CTX *ctx;
 817     int keylen;
 818     X509_ALGOR *talg, *wrap_alg = NULL;
 819     ASN1_OBJECT *aoid;
 820     ASN1_BIT_STRING *pubkey;
 821     ASN1_STRING *wrap_str;
 822     ASN1_OCTET_STRING *ukm;
 823     unsigned char *penc = NULL, *dukm = NULL;
 824     int penclen;
 825     size_t dukmlen = 0;
 826     int rv = 0;
 827     int kdf_type, wrap_nid;
 828     const EVP_MD *kdf_md;
 829     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 830     if (!pctx)
 831         return 0;
 832     /* Get ephemeral key */
 833     pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 834     if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
 835                                              NULL, NULL, NULL))
 836         goto err;
 837     X509_ALGOR_get0(&aoid, NULL, NULL, talg);
 838     /* Is everything uninitialised? */
 839     if (aoid == OBJ_nid2obj(NID_undef)) {
 840         ASN1_INTEGER *pubk = BN_to_ASN1_INTEGER(pkey->pkey.dh->pub_key, NULL);
 841         if (!pubk)
 842             goto err;
 843         /* Set the key */
 844
 845         penclen = i2d_ASN1_INTEGER(pubk, &penc);
 846         ASN1_INTEGER_free(pubk);
 847         if (penclen <= 0)
 848             goto err;
 849         ASN1_STRING_set0(pubkey, penc, penclen);
 850         pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 851         pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 852
 853         penc = NULL;
 854         X509_ALGOR_set0(talg, OBJ_nid2obj(NID_dhpublicnumber),
 855                         V_ASN1_UNDEF, NULL);
 856     }
 857
 858     /* See if custom paraneters set */
 859     kdf_type = EVP_PKEY_CTX_get_dh_kdf_type(pctx);
 860     if (kdf_type <= 0)
 861         goto err;
 862     if (!EVP_PKEY_CTX_get_dh_kdf_md(pctx, &kdf_md))
 863         goto err;
 864
 865     if (kdf_type == EVP_PKEY_DH_KDF_NONE) {
 866         kdf_type = EVP_PKEY_DH_KDF_X9_42;
 867         if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, kdf_type) <= 0)
 868             goto err;
 869     } else if (kdf_type != EVP_PKEY_DH_KDF_X9_42)
 870         /* Unknown KDF */
 871         goto err;
 872     if (kdf_md == NULL) {
 873         /* Only SHA1 supported */
 874         kdf_md = EVP_sha1();
 875         if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, kdf_md) <= 0)
 876             goto err;
 877     } else if (EVP_MD_type(kdf_md) != NID_sha1)
 878         /* Unsupported digest */
 879         goto err;
 880
 881     if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
 882         goto err;
 883
 884     /* Get wrap NID */
 885     ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 886     wrap_nid = EVP_CIPHER_CTX_type(ctx);
 887     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx, OBJ_nid2obj(wrap_nid)) <= 0)
 888         goto err;
 889     keylen = EVP_CIPHER_CTX_key_length(ctx);
 890
 891     /* Package wrap algorithm in an AlgorithmIdentifier */
 892
 893     wrap_alg = X509_ALGOR_new();
 894     if (!wrap_alg)
 895         goto err;
 896     wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
 897     wrap_alg->parameter = ASN1_TYPE_new();
 898     if (!wrap_alg->parameter)
 899         goto err;
 900     if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
 901         goto err;
 902     if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
 903         ASN1_TYPE_free(wrap_alg->parameter);
 904         wrap_alg->parameter = NULL;
 905     }
 906
 907     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 908         goto err;
 909
 910     if (ukm) {
 911         dukmlen = ASN1_STRING_length(ukm);
 912         dukm = BUF_memdup(ASN1_STRING_data(ukm), dukmlen);
 913         if (!dukm)
 914             goto err;
 915     }
 916
 917     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 918         goto err;
 919     dukm = NULL;
 920
 921     /*
 922      * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
 923      * of another AlgorithmIdentifier.
 924      */
 925     penc = NULL;
 926     penclen = i2d_X509_ALGOR(wrap_alg, &penc);
 927     if (!penc || !penclen)
 928         goto err;
 929     wrap_str = ASN1_STRING_new();
 930     if (!wrap_str)
 931         goto err;
 932     ASN1_STRING_set0(wrap_str, penc, penclen);
 933     penc = NULL;
 934     X509_ALGOR_set0(talg, OBJ_nid2obj(NID_id_smime_alg_ESDH),
 935                     V_ASN1_SEQUENCE, wrap_str);
 936
 937     rv = 1;
 938
 939  err:
 940     OPENSSL_free(penc);
 941     X509_ALGOR_free(wrap_alg);
 942     return rv;
 943 }
 944
 945 #endif