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     if (public_key)
 144         ASN1_INTEGER_free(public_key);
 145     DH_free(dh);
 146     return 0;
 147
 148 }
 149
 150 static int dh_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
 151 {
 152     DH *dh;
 153     int ptype;
 154     unsigned char *penc = NULL;
 155     int penclen;
 156     ASN1_STRING *str;
 157     ASN1_INTEGER *pub_key = NULL;
 158
 159     dh = pkey->pkey.dh;
 160
 161     str = ASN1_STRING_new();
 162     if (!str) {
 163         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 164         goto err;
 165     }
 166     str->length = i2d_dhp(pkey, dh, &str->data);
 167     if (str->length <= 0) {
 168         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 169         goto err;
 170     }
 171     ptype = V_ASN1_SEQUENCE;
 172
 173     pub_key = BN_to_ASN1_INTEGER(dh->pub_key, NULL);
 174     if (!pub_key)
 175         goto err;
 176
 177     penclen = i2d_ASN1_INTEGER(pub_key, &penc);
 178
 179     ASN1_INTEGER_free(pub_key);
 180
 181     if (penclen <= 0) {
 182         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 183         goto err;
 184     }
 185
 186     if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
 187                                ptype, str, penc, penclen))
 188         return 1;
 189
 190  err:
 191     if (penc)
 192         OPENSSL_free(penc);
 193     ASN1_STRING_free(str);
 194
 195     return 0;
 196 }
 197
 198 /*
 199  * PKCS#8 DH is defined in PKCS#11 of all places. It is similar to DH in that
 200  * the AlgorithmIdentifier contains the parameters, the private key is
 201  * explcitly included and the pubkey must be recalculated.
 202  */
 203
 204 static int dh_priv_decode(EVP_PKEY *pkey, PKCS8_PRIV_KEY_INFO *p8)
 205 {
 206     const unsigned char *p, *pm;
 207     int pklen, pmlen;
 208     int ptype;
 209     void *pval;
 210     ASN1_STRING *pstr;
 211     X509_ALGOR *palg;
 212     ASN1_INTEGER *privkey = NULL;
 213
 214     DH *dh = NULL;
 215
 216     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 217         return 0;
 218
 219     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 220
 221     if (ptype != V_ASN1_SEQUENCE)
 222         goto decerr;
 223
 224     if (!(privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)))
 225         goto decerr;
 226
 227     pstr = pval;
 228     pm = pstr->data;
 229     pmlen = pstr->length;
 230     if (!(dh = d2i_dhp(pkey, &pm, pmlen)))
 231         goto decerr;
 232     /* We have parameters now set private key */
 233     if (!(dh->priv_key = ASN1_INTEGER_to_BN(privkey, NULL))) {
 234         DHerr(DH_F_DH_PRIV_DECODE, DH_R_BN_ERROR);
 235         goto dherr;
 236     }
 237     /* Calculate public key */
 238     if (!DH_generate_key(dh))
 239         goto dherr;
 240
 241     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 242
 243     ASN1_STRING_clear_free(privkey);
 244
 245     return 1;
 246
 247  decerr:
 248     DHerr(DH_F_DH_PRIV_DECODE, EVP_R_DECODE_ERROR);
 249  dherr:
 250     DH_free(dh);
 251     ASN1_STRING_clear_free(privkey);
 252     return 0;
 253 }
 254
 255 static int dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 256 {
 257     ASN1_STRING *params = NULL;
 258     ASN1_INTEGER *prkey = NULL;
 259     unsigned char *dp = NULL;
 260     int dplen;
 261
 262     params = ASN1_STRING_new();
 263
 264     if (!params) {
 265         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 266         goto err;
 267     }
 268
 269     params->length = i2d_dhp(pkey, pkey->pkey.dh, &params->data);
 270     if (params->length <= 0) {
 271         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 272         goto err;
 273     }
 274     params->type = V_ASN1_SEQUENCE;
 275
 276     /* Get private key into integer */
 277     prkey = BN_to_ASN1_INTEGER(pkey->pkey.dh->priv_key, NULL);
 278
 279     if (!prkey) {
 280         DHerr(DH_F_DH_PRIV_ENCODE, DH_R_BN_ERROR);
 281         goto err;
 282     }
 283
 284     dplen = i2d_ASN1_INTEGER(prkey, &dp);
 285
 286     ASN1_STRING_clear_free(prkey);
 287     prkey = NULL;
 288
 289     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
 290                          V_ASN1_SEQUENCE, params, dp, dplen))
 291         goto err;
 292
 293     return 1;
 294
 295  err:
 296     if (dp != NULL)
 297         OPENSSL_free(dp);
 298     ASN1_STRING_free(params);
 299     if (prkey != NULL)
 300         ASN1_STRING_clear_free(prkey);
 301     return 0;
 302 }
 303
 304 static void update_buflen(const BIGNUM *b, size_t *pbuflen)
 305 {
 306     size_t i;
 307     if (!b)
 308         return;
 309     if (*pbuflen < (i = (size_t)BN_num_bytes(b)))
 310         *pbuflen = i;
 311 }
 312
 313 static int dh_param_decode(EVP_PKEY *pkey,
 314                            const unsigned char **pder, int derlen)
 315 {
 316     DH *dh;
 317     if (!(dh = d2i_dhp(pkey, pder, derlen))) {
 318         DHerr(DH_F_DH_PARAM_DECODE, ERR_R_DH_LIB);
 319         return 0;
 320     }
 321     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 322     return 1;
 323 }
 324
 325 static int dh_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 326 {
 327     return i2d_dhp(pkey, pkey->pkey.dh, pder);
 328 }
 329
 330 static int do_dh_print(BIO *bp, const DH *x, int indent,
 331                        ASN1_PCTX *ctx, int ptype)
 332 {
 333     unsigned char *m = NULL;
 334     int reason = ERR_R_BUF_LIB, ret = 0;
 335     size_t buf_len = 0;
 336
 337     const char *ktype = NULL;
 338
 339     BIGNUM *priv_key, *pub_key;
 340
 341     if (ptype == 2)
 342         priv_key = x->priv_key;
 343     else
 344         priv_key = NULL;
 345
 346     if (ptype > 0)
 347         pub_key = x->pub_key;
 348     else
 349         pub_key = NULL;
 350
 351     update_buflen(x->p, &buf_len);
 352
 353     if (buf_len == 0) {
 354         reason = ERR_R_PASSED_NULL_PARAMETER;
 355         goto err;
 356     }
 357
 358     update_buflen(x->g, &buf_len);
 359     update_buflen(x->q, &buf_len);
 360     update_buflen(x->j, &buf_len);
 361     update_buflen(x->counter, &buf_len);
 362     update_buflen(pub_key, &buf_len);
 363     update_buflen(priv_key, &buf_len);
 364
 365     if (ptype == 2)
 366         ktype = "DH Private-Key";
 367     else if (ptype == 1)
 368         ktype = "DH Public-Key";
 369     else
 370         ktype = "DH Parameters";
 371
 372     m = OPENSSL_malloc(buf_len + 10);
 373     if (m == NULL) {
 374         reason = ERR_R_MALLOC_FAILURE;
 375         goto err;
 376     }
 377
 378     BIO_indent(bp, indent, 128);
 379     if (BIO_printf(bp, "%s: (%d bit)\n", ktype, BN_num_bits(x->p)) <= 0)
 380         goto err;
 381     indent += 4;
 382
 383     if (!ASN1_bn_print(bp, "private-key:", priv_key, m, indent))
 384         goto err;
 385     if (!ASN1_bn_print(bp, "public-key:", pub_key, m, indent))
 386         goto err;
 387
 388     if (!ASN1_bn_print(bp, "prime:", x->p, m, indent))
 389         goto err;
 390     if (!ASN1_bn_print(bp, "generator:", x->g, m, indent))
 391         goto err;
 392     if (x->q && !ASN1_bn_print(bp, "subgroup order:", x->q, m, indent))
 393         goto err;
 394     if (x->j && !ASN1_bn_print(bp, "subgroup factor:", x->j, m, indent))
 395         goto err;
 396     if (x->seed) {
 397         int i;
 398         BIO_indent(bp, indent, 128);
 399         BIO_puts(bp, "seed:");
 400         for (i = 0; i < x->seedlen; i++) {
 401             if ((i % 15) == 0) {
 402                 if (BIO_puts(bp, "\n") <= 0
 403                     || !BIO_indent(bp, indent + 4, 128))
 404                     goto err;
 405             }
 406             if (BIO_printf(bp, "%02x%s", x->seed[i],
 407                            ((i + 1) == x->seedlen) ? "" : ":") <= 0)
 408                 goto err;
 409         }
 410         if (BIO_write(bp, "\n", 1) <= 0)
 411             return (0);
 412     }
 413     if (x->counter && !ASN1_bn_print(bp, "counter:", x->counter, m, indent))
 414         goto err;
 415     if (x->length != 0) {
 416         BIO_indent(bp, indent, 128);
 417         if (BIO_printf(bp, "recommended-private-length: %d bits\n",
 418                        (int)x->length) <= 0)
 419             goto err;
 420     }
 421
 422     ret = 1;
 423     if (0) {
 424  err:
 425         DHerr(DH_F_DO_DH_PRINT, reason);
 426     }
 427     if (m != NULL)
 428         OPENSSL_free(m);
 429     return (ret);
 430 }
 431
 432 static int int_dh_size(const EVP_PKEY *pkey)
 433 {
 434     return (DH_size(pkey->pkey.dh));
 435 }
 436
 437 static int dh_bits(const EVP_PKEY *pkey)
 438 {
 439     return BN_num_bits(pkey->pkey.dh->p);
 440 }
 441
 442 static int dh_security_bits(const EVP_PKEY *pkey)
 443 {
 444     return DH_security_bits(pkey->pkey.dh);
 445 }
 446
 447 static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 448 {
 449     if (BN_cmp(a->pkey.dh->p, b->pkey.dh->p) ||
 450         BN_cmp(a->pkey.dh->g, b->pkey.dh->g))
 451         return 0;
 452     else if (a->ameth == &dhx_asn1_meth) {
 453         if (BN_cmp(a->pkey.dh->q, b->pkey.dh->q))
 454             return 0;
 455     }
 456     return 1;
 457 }
 458
 459 static int int_dh_bn_cpy(BIGNUM **dst, const BIGNUM *src)
 460 {
 461     BIGNUM *a;
 462     if (src) {
 463         a = BN_dup(src);
 464         if (!a)
 465             return 0;
 466     } else
 467         a = NULL;
 468     if (*dst)
 469         BN_free(*dst);
 470     *dst = a;
 471     return 1;
 472 }
 473
 474 static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
 475 {
 476     if (is_x942 == -1)
 477         is_x942 = ! !from->q;
 478     if (!int_dh_bn_cpy(&to->p, from->p))
 479         return 0;
 480     if (!int_dh_bn_cpy(&to->g, from->g))
 481         return 0;
 482     if (is_x942) {
 483         if (!int_dh_bn_cpy(&to->q, from->q))
 484             return 0;
 485         if (!int_dh_bn_cpy(&to->j, from->j))
 486             return 0;
 487         if (to->seed) {
 488             OPENSSL_free(to->seed);
 489             to->seed = NULL;
 490             to->seedlen = 0;
 491         }
 492         if (from->seed) {
 493             to->seed = BUF_memdup(from->seed, from->seedlen);
 494             if (!to->seed)
 495                 return 0;
 496             to->seedlen = from->seedlen;
 497         }
 498     } else
 499         to->length = from->length;
 500     return 1;
 501 }
 502
 503 DH *DHparams_dup(DH *dh)
 504 {
 505     DH *ret;
 506     ret = DH_new();
 507     if (!ret)
 508         return NULL;
 509     if (!int_dh_param_copy(ret, dh, -1)) {
 510         DH_free(ret);
 511         return NULL;
 512     }
 513     return ret;
 514 }
 515
 516 static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 517 {
 518     return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
 519                              from->ameth == &dhx_asn1_meth);
 520 }
 521
 522 static int dh_missing_parameters(const EVP_PKEY *a)
 523 {
 524     if (!a->pkey.dh->p || !a->pkey.dh->g)
 525         return 1;
 526     return 0;
 527 }
 528
 529 static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 530 {
 531     if (dh_cmp_parameters(a, b) == 0)
 532         return 0;
 533     if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
 534         return 0;
 535     else
 536         return 1;
 537 }
 538
 539 static int dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 540                           ASN1_PCTX *ctx)
 541 {
 542     return do_dh_print(bp, pkey->pkey.dh, indent, ctx, 0);
 543 }
 544
 545 static int dh_public_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 546                            ASN1_PCTX *ctx)
 547 {
 548     return do_dh_print(bp, pkey->pkey.dh, indent, ctx, 1);
 549 }
 550
 551 static int dh_private_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 552                             ASN1_PCTX *ctx)
 553 {
 554     return do_dh_print(bp, pkey->pkey.dh, indent, ctx, 2);
 555 }
 556
 557 int DHparams_print(BIO *bp, const DH *x)
 558 {
 559     return do_dh_print(bp, x, 4, NULL, 0);
 560 }
 561
 562 #ifndef OPENSSL_NO_CMS
 563 static int dh_cms_decrypt(CMS_RecipientInfo *ri);
 564 static int dh_cms_encrypt(CMS_RecipientInfo *ri);
 565 #endif
 566
 567 static int dh_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 568 {
 569     switch (op) {
 570 #ifndef OPENSSL_NO_CMS
 571
 572     case ASN1_PKEY_CTRL_CMS_ENVELOPE:
 573         if (arg1 == 1)
 574             return dh_cms_decrypt(arg2);
 575         else if (arg1 == 0)
 576             return dh_cms_encrypt(arg2);
 577         return -2;
 578
 579     case ASN1_PKEY_CTRL_CMS_RI_TYPE:
 580         *(int *)arg2 = CMS_RECIPINFO_AGREE;
 581         return 1;
 582 #endif
 583     default:
 584         return -2;
 585     }
 586
 587 }
 588
 589 const EVP_PKEY_ASN1_METHOD dh_asn1_meth = {
 590     EVP_PKEY_DH,
 591     EVP_PKEY_DH,
 592     0,
 593
 594     "DH",
 595     "OpenSSL PKCS#3 DH method",
 596
 597     dh_pub_decode,
 598     dh_pub_encode,
 599     dh_pub_cmp,
 600     dh_public_print,
 601
 602     dh_priv_decode,
 603     dh_priv_encode,
 604     dh_private_print,
 605
 606     int_dh_size,
 607     dh_bits,
 608     dh_security_bits,
 609
 610     dh_param_decode,
 611     dh_param_encode,
 612     dh_missing_parameters,
 613     dh_copy_parameters,
 614     dh_cmp_parameters,
 615     dh_param_print,
 616     0,
 617
 618     int_dh_free,
 619     0
 620 };
 621
 622 const EVP_PKEY_ASN1_METHOD dhx_asn1_meth = {
 623     EVP_PKEY_DHX,
 624     EVP_PKEY_DHX,
 625     0,
 626
 627     "X9.42 DH",
 628     "OpenSSL X9.42 DH method",
 629
 630     dh_pub_decode,
 631     dh_pub_encode,
 632     dh_pub_cmp,
 633     dh_public_print,
 634
 635     dh_priv_decode,
 636     dh_priv_encode,
 637     dh_private_print,
 638
 639     int_dh_size,
 640     dh_bits,
 641     dh_security_bits,
 642
 643     dh_param_decode,
 644     dh_param_encode,
 645     dh_missing_parameters,
 646     dh_copy_parameters,
 647     dh_cmp_parameters,
 648     dh_param_print,
 649     0,
 650
 651     int_dh_free,
 652     dh_pkey_ctrl
 653 };
 654
 655 #ifndef OPENSSL_NO_CMS
 656
 657 static int dh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
 658                               X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 659 {
 660     ASN1_OBJECT *aoid;
 661     int atype;
 662     void *aval;
 663     ASN1_INTEGER *public_key = NULL;
 664     int rv = 0;
 665     EVP_PKEY *pkpeer = NULL, *pk = NULL;
 666     DH *dhpeer = NULL;
 667     const unsigned char *p;
 668     int plen;
 669
 670     X509_ALGOR_get0(&aoid, &atype, &aval, alg);
 671     if (OBJ_obj2nid(aoid) != NID_dhpublicnumber)
 672         goto err;
 673     /* Only absent parameters allowed in RFC XXXX */
 674     if (atype != V_ASN1_UNDEF && atype == V_ASN1_NULL)
 675         goto err;
 676
 677     pk = EVP_PKEY_CTX_get0_pkey(pctx);
 678     if (!pk)
 679         goto err;
 680     if (pk->type != EVP_PKEY_DHX)
 681         goto err;
 682     /* Get parameters from parent key */
 683     dhpeer = DHparams_dup(pk->pkey.dh);
 684     /* We have parameters now set public key */
 685     plen = ASN1_STRING_length(pubkey);
 686     p = ASN1_STRING_data(pubkey);
 687     if (!p || !plen)
 688         goto err;
 689
 690     if (!(public_key = d2i_ASN1_INTEGER(NULL, &p, plen))) {
 691         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_DECODE_ERROR);
 692         goto err;
 693     }
 694
 695     /* We have parameters now set public key */
 696     if (!(dhpeer->pub_key = ASN1_INTEGER_to_BN(public_key, NULL))) {
 697         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_BN_DECODE_ERROR);
 698         goto err;
 699     }
 700
 701     pkpeer = EVP_PKEY_new();
 702     if (!pkpeer)
 703         goto err;
 704     EVP_PKEY_assign(pkpeer, pk->ameth->pkey_id, dhpeer);
 705     dhpeer = NULL;
 706     if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
 707         rv = 1;
 708  err:
 709     if (public_key)
 710         ASN1_INTEGER_free(public_key);
 711     EVP_PKEY_free(pkpeer);
 712     DH_free(dhpeer);
 713     return rv;
 714 }
 715
 716 static int dh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 717 {
 718     int rv = 0;
 719
 720     X509_ALGOR *alg, *kekalg = NULL;
 721     ASN1_OCTET_STRING *ukm;
 722     const unsigned char *p;
 723     unsigned char *dukm = NULL;
 724     size_t dukmlen = 0;
 725     int keylen, plen;
 726     const EVP_CIPHER *kekcipher;
 727     EVP_CIPHER_CTX *kekctx;
 728
 729     if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
 730         goto err;
 731
 732     /*
 733      * For DH we only have one OID permissible. If ever any more get defined
 734      * we will need something cleverer.
 735      */
 736     if (OBJ_obj2nid(alg->algorithm) != NID_id_smime_alg_ESDH) {
 737         DHerr(DH_F_DH_CMS_SET_SHARED_INFO, DH_R_KDF_PARAMETER_ERROR);
 738         goto err;
 739     }
 740
 741     if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, EVP_PKEY_DH_KDF_X9_42) <= 0)
 742         goto err;
 743
 744     if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, EVP_sha1()) <= 0)
 745         goto err;
 746
 747     if (alg->parameter->type != V_ASN1_SEQUENCE)
 748         goto err;
 749
 750     p = alg->parameter->value.sequence->data;
 751     plen = alg->parameter->value.sequence->length;
 752     kekalg = d2i_X509_ALGOR(NULL, &p, plen);
 753     if (!kekalg)
 754         goto err;
 755     kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 756     if (!kekctx)
 757         goto err;
 758     kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
 759     if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
 760         goto err;
 761     if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
 762         goto err;
 763     if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
 764         goto err;
 765
 766     keylen = EVP_CIPHER_CTX_key_length(kekctx);
 767     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 768         goto err;
 769     /* Use OBJ_nid2obj to ensure we use built in OID that isn't freed */
 770     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx,
 771                                      OBJ_nid2obj(EVP_CIPHER_type(kekcipher)))
 772         <= 0)
 773         goto err;
 774
 775     if (ukm) {
 776         dukmlen = ASN1_STRING_length(ukm);
 777         dukm = BUF_memdup(ASN1_STRING_data(ukm), dukmlen);
 778         if (!dukm)
 779             goto err;
 780     }
 781
 782     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 783         goto err;
 784     dukm = NULL;
 785
 786     rv = 1;
 787  err:
 788     if (kekalg)
 789         X509_ALGOR_free(kekalg);
 790     if (dukm)
 791         OPENSSL_free(dukm);
 792     return rv;
 793 }
 794
 795 static int dh_cms_decrypt(CMS_RecipientInfo *ri)
 796 {
 797     EVP_PKEY_CTX *pctx;
 798     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 799     if (!pctx)
 800         return 0;
 801     /* See if we need to set peer key */
 802     if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
 803         X509_ALGOR *alg;
 804         ASN1_BIT_STRING *pubkey;
 805         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
 806                                                  NULL, NULL, NULL))
 807             return 0;
 808         if (!alg || !pubkey)
 809             return 0;
 810         if (!dh_cms_set_peerkey(pctx, alg, pubkey)) {
 811             DHerr(DH_F_DH_CMS_DECRYPT, DH_R_PEER_KEY_ERROR);
 812             return 0;
 813         }
 814     }
 815     /* Set DH derivation parameters and initialise unwrap context */
 816     if (!dh_cms_set_shared_info(pctx, ri)) {
 817         DHerr(DH_F_DH_CMS_DECRYPT, DH_R_SHARED_INFO_ERROR);
 818         return 0;
 819     }
 820     return 1;
 821 }
 822
 823 static int dh_cms_encrypt(CMS_RecipientInfo *ri)
 824 {
 825     EVP_PKEY_CTX *pctx;
 826     EVP_PKEY *pkey;
 827     EVP_CIPHER_CTX *ctx;
 828     int keylen;
 829     X509_ALGOR *talg, *wrap_alg = NULL;
 830     ASN1_OBJECT *aoid;
 831     ASN1_BIT_STRING *pubkey;
 832     ASN1_STRING *wrap_str;
 833     ASN1_OCTET_STRING *ukm;
 834     unsigned char *penc = NULL, *dukm = NULL;
 835     int penclen;
 836     size_t dukmlen = 0;
 837     int rv = 0;
 838     int kdf_type, wrap_nid;
 839     const EVP_MD *kdf_md;
 840     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 841     if (!pctx)
 842         return 0;
 843     /* Get ephemeral key */
 844     pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 845     if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
 846                                              NULL, NULL, NULL))
 847         goto err;
 848     X509_ALGOR_get0(&aoid, NULL, NULL, talg);
 849     /* Is everything uninitialised? */
 850     if (aoid == OBJ_nid2obj(NID_undef)) {
 851         ASN1_INTEGER *pubk = BN_to_ASN1_INTEGER(pkey->pkey.dh->pub_key, NULL);
 852         if (!pubk)
 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 paraneters 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)
 906         goto err;
 907     wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
 908     wrap_alg->parameter = ASN1_TYPE_new();
 909     if (!wrap_alg->parameter)
 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 = BUF_memdup(ASN1_STRING_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 || !penclen)
 939         goto err;
 940     wrap_str = ASN1_STRING_new();
 941     if (!wrap_str)
 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     if (penc)
 952         OPENSSL_free(penc);
 953     if (wrap_alg)
 954         X509_ALGOR_free(wrap_alg);
 955     return rv;
 956 }
 957
 958 #endif