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 "internal/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)) == NULL) {
 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)) == NULL) {
 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)) == 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     if ((privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL)
 222         goto decerr;
 223
 224     pstr = pval;
 225     pm = pstr->data;
 226     pmlen = pstr->length;
 227     if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL)
 228         goto decerr;
 229
 230     /* We have parameters now set private key */
 231     if ((dh->priv_key = BN_secure_new()) == NULL
 232         || !ASN1_INTEGER_to_BN(privkey, dh->priv_key)) {
 233         DHerr(DH_F_DH_PRIV_DECODE, DH_R_BN_ERROR);
 234         goto dherr;
 235     }
 236     /* Calculate public key */
 237     if (!DH_generate_key(dh))
 238         goto dherr;
 239
 240     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 241
 242     ASN1_STRING_clear_free(privkey);
 243
 244     return 1;
 245
 246  decerr:
 247     DHerr(DH_F_DH_PRIV_DECODE, EVP_R_DECODE_ERROR);
 248  dherr:
 249     DH_free(dh);
 250     ASN1_STRING_clear_free(privkey);
 251     return 0;
 252 }
 253
 254 static int dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 255 {
 256     ASN1_STRING *params = NULL;
 257     ASN1_INTEGER *prkey = NULL;
 258     unsigned char *dp = NULL;
 259     int dplen;
 260
 261     params = ASN1_STRING_new();
 262
 263     if (!params) {
 264         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 265         goto err;
 266     }
 267
 268     params->length = i2d_dhp(pkey, pkey->pkey.dh, &params->data);
 269     if (params->length <= 0) {
 270         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 271         goto err;
 272     }
 273     params->type = V_ASN1_SEQUENCE;
 274
 275     /* Get private key into integer */
 276     prkey = BN_to_ASN1_INTEGER(pkey->pkey.dh->priv_key, NULL);
 277
 278     if (!prkey) {
 279         DHerr(DH_F_DH_PRIV_ENCODE, DH_R_BN_ERROR);
 280         goto err;
 281     }
 282
 283     dplen = i2d_ASN1_INTEGER(prkey, &dp);
 284
 285     ASN1_STRING_clear_free(prkey);
 286     prkey = NULL;
 287
 288     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
 289                          V_ASN1_SEQUENCE, params, dp, dplen))
 290         goto err;
 291
 292     return 1;
 293
 294  err:
 295     OPENSSL_free(dp);
 296     ASN1_STRING_free(params);
 297     ASN1_STRING_clear_free(prkey);
 298     return 0;
 299 }
 300
 301 static void update_buflen(const BIGNUM *b, size_t *pbuflen)
 302 {
 303     size_t i;
 304     if (!b)
 305         return;
 306     if (*pbuflen < (i = (size_t)BN_num_bytes(b)))
 307         *pbuflen = i;
 308 }
 309
 310 static int dh_param_decode(EVP_PKEY *pkey,
 311                            const unsigned char **pder, int derlen)
 312 {
 313     DH *dh;
 314
 315     if ((dh = d2i_dhp(pkey, pder, derlen)) == NULL) {
 316         DHerr(DH_F_DH_PARAM_DECODE, ERR_R_DH_LIB);
 317         return 0;
 318     }
 319     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 320     return 1;
 321 }
 322
 323 static int dh_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 324 {
 325     return i2d_dhp(pkey, pkey->pkey.dh, pder);
 326 }
 327
 328 static int do_dh_print(BIO *bp, const DH *x, int indent,
 329                        ASN1_PCTX *ctx, int ptype)
 330 {
 331     unsigned char *m = NULL;
 332     int reason = ERR_R_BUF_LIB;
 333     size_t buf_len = 0;
 334
 335     const char *ktype = NULL;
 336
 337     BIGNUM *priv_key, *pub_key;
 338
 339     if (ptype == 2)
 340         priv_key = x->priv_key;
 341     else
 342         priv_key = NULL;
 343
 344     if (ptype > 0)
 345         pub_key = x->pub_key;
 346     else
 347         pub_key = NULL;
 348
 349     update_buflen(x->p, &buf_len);
 350
 351     if (buf_len == 0) {
 352         reason = ERR_R_PASSED_NULL_PARAMETER;
 353         goto err;
 354     }
 355
 356     update_buflen(x->g, &buf_len);
 357     update_buflen(x->q, &buf_len);
 358     update_buflen(x->j, &buf_len);
 359     update_buflen(x->counter, &buf_len);
 360     update_buflen(pub_key, &buf_len);
 361     update_buflen(priv_key, &buf_len);
 362
 363     if (ptype == 2)
 364         ktype = "DH Private-Key";
 365     else if (ptype == 1)
 366         ktype = "DH Public-Key";
 367     else
 368         ktype = "DH Parameters";
 369
 370     m = OPENSSL_malloc(buf_len + 10);
 371     if (m == NULL) {
 372         reason = ERR_R_MALLOC_FAILURE;
 373         goto err;
 374     }
 375
 376     BIO_indent(bp, indent, 128);
 377     if (BIO_printf(bp, "%s: (%d bit)\n", ktype, BN_num_bits(x->p)) <= 0)
 378         goto err;
 379     indent += 4;
 380
 381     if (!ASN1_bn_print(bp, "private-key:", priv_key, m, indent))
 382         goto err;
 383     if (!ASN1_bn_print(bp, "public-key:", pub_key, m, indent))
 384         goto err;
 385
 386     if (!ASN1_bn_print(bp, "prime:", x->p, m, indent))
 387         goto err;
 388     if (!ASN1_bn_print(bp, "generator:", x->g, m, indent))
 389         goto err;
 390     if (x->q && !ASN1_bn_print(bp, "subgroup order:", x->q, m, indent))
 391         goto err;
 392     if (x->j && !ASN1_bn_print(bp, "subgroup factor:", x->j, m, indent))
 393         goto err;
 394     if (x->seed) {
 395         int i;
 396         BIO_indent(bp, indent, 128);
 397         BIO_puts(bp, "seed:");
 398         for (i = 0; i < x->seedlen; i++) {
 399             if ((i % 15) == 0) {
 400                 if (BIO_puts(bp, "\n") <= 0
 401                     || !BIO_indent(bp, indent + 4, 128))
 402                     goto err;
 403             }
 404             if (BIO_printf(bp, "%02x%s", x->seed[i],
 405                            ((i + 1) == x->seedlen) ? "" : ":") <= 0)
 406                 goto err;
 407         }
 408         if (BIO_write(bp, "\n", 1) <= 0)
 409             return (0);
 410     }
 411     if (x->counter && !ASN1_bn_print(bp, "counter:", x->counter, m, indent))
 412         goto err;
 413     if (x->length != 0) {
 414         BIO_indent(bp, indent, 128);
 415         if (BIO_printf(bp, "recommended-private-length: %d bits\n",
 416                        (int)x->length) <= 0)
 417             goto err;
 418     }
 419
 420     OPENSSL_free(m);
 421     return 1;
 422
 423  err:
 424     DHerr(DH_F_DO_DH_PRINT, reason);
 425     OPENSSL_free(m);
 426     return 0;
 427 }
 428
 429 static int int_dh_size(const EVP_PKEY *pkey)
 430 {
 431     return (DH_size(pkey->pkey.dh));
 432 }
 433
 434 static int dh_bits(const EVP_PKEY *pkey)
 435 {
 436     return BN_num_bits(pkey->pkey.dh->p);
 437 }
 438
 439 static int dh_security_bits(const EVP_PKEY *pkey)
 440 {
 441     return DH_security_bits(pkey->pkey.dh);
 442 }
 443
 444 static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 445 {
 446     if (BN_cmp(a->pkey.dh->p, b->pkey.dh->p) ||
 447         BN_cmp(a->pkey.dh->g, b->pkey.dh->g))
 448         return 0;
 449     else if (a->ameth == &dhx_asn1_meth) {
 450         if (BN_cmp(a->pkey.dh->q, b->pkey.dh->q))
 451             return 0;
 452     }
 453     return 1;
 454 }
 455
 456 static int int_dh_bn_cpy(BIGNUM **dst, const BIGNUM *src)
 457 {
 458     BIGNUM *a;
 459     if (src) {
 460         a = BN_dup(src);
 461         if (!a)
 462             return 0;
 463     } else
 464         a = NULL;
 465     BN_free(*dst);
 466     *dst = a;
 467     return 1;
 468 }
 469
 470 static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
 471 {
 472     if (is_x942 == -1)
 473         is_x942 = ! !from->q;
 474     if (!int_dh_bn_cpy(&to->p, from->p))
 475         return 0;
 476     if (!int_dh_bn_cpy(&to->g, from->g))
 477         return 0;
 478     if (is_x942) {
 479         if (!int_dh_bn_cpy(&to->q, from->q))
 480             return 0;
 481         if (!int_dh_bn_cpy(&to->j, from->j))
 482             return 0;
 483         OPENSSL_free(to->seed);
 484         to->seed = NULL;
 485         to->seedlen = 0;
 486         if (from->seed) {
 487             to->seed = BUF_memdup(from->seed, from->seedlen);
 488             if (!to->seed)
 489                 return 0;
 490             to->seedlen = from->seedlen;
 491         }
 492     } else
 493         to->length = from->length;
 494     return 1;
 495 }
 496
 497 DH *DHparams_dup(DH *dh)
 498 {
 499     DH *ret;
 500     ret = DH_new();
 501     if (!ret)
 502         return NULL;
 503     if (!int_dh_param_copy(ret, dh, -1)) {
 504         DH_free(ret);
 505         return NULL;
 506     }
 507     return ret;
 508 }
 509
 510 static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 511 {
 512     return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
 513                              from->ameth == &dhx_asn1_meth);
 514 }
 515
 516 static int dh_missing_parameters(const EVP_PKEY *a)
 517 {
 518     if (!a->pkey.dh->p || !a->pkey.dh->g)
 519         return 1;
 520     return 0;
 521 }
 522
 523 static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 524 {
 525     if (dh_cmp_parameters(a, b) == 0)
 526         return 0;
 527     if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
 528         return 0;
 529     else
 530         return 1;
 531 }
 532
 533 static int dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 534                           ASN1_PCTX *ctx)
 535 {
 536     return do_dh_print(bp, pkey->pkey.dh, indent, ctx, 0);
 537 }
 538
 539 static int dh_public_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, 1);
 543 }
 544
 545 static int dh_private_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, 2);
 549 }
 550
 551 int DHparams_print(BIO *bp, const DH *x)
 552 {
 553     return do_dh_print(bp, x, 4, NULL, 0);
 554 }
 555
 556 #ifndef OPENSSL_NO_CMS
 557 static int dh_cms_decrypt(CMS_RecipientInfo *ri);
 558 static int dh_cms_encrypt(CMS_RecipientInfo *ri);
 559 #endif
 560
 561 static int dh_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 562 {
 563     switch (op) {
 564 #ifndef OPENSSL_NO_CMS
 565
 566     case ASN1_PKEY_CTRL_CMS_ENVELOPE:
 567         if (arg1 == 1)
 568             return dh_cms_decrypt(arg2);
 569         else if (arg1 == 0)
 570             return dh_cms_encrypt(arg2);
 571         return -2;
 572
 573     case ASN1_PKEY_CTRL_CMS_RI_TYPE:
 574         *(int *)arg2 = CMS_RECIPINFO_AGREE;
 575         return 1;
 576 #endif
 577     default:
 578         return -2;
 579     }
 580
 581 }
 582
 583 const EVP_PKEY_ASN1_METHOD dh_asn1_meth = {
 584     EVP_PKEY_DH,
 585     EVP_PKEY_DH,
 586     0,
 587
 588     "DH",
 589     "OpenSSL PKCS#3 DH method",
 590
 591     dh_pub_decode,
 592     dh_pub_encode,
 593     dh_pub_cmp,
 594     dh_public_print,
 595
 596     dh_priv_decode,
 597     dh_priv_encode,
 598     dh_private_print,
 599
 600     int_dh_size,
 601     dh_bits,
 602     dh_security_bits,
 603
 604     dh_param_decode,
 605     dh_param_encode,
 606     dh_missing_parameters,
 607     dh_copy_parameters,
 608     dh_cmp_parameters,
 609     dh_param_print,
 610     0,
 611
 612     int_dh_free,
 613     0
 614 };
 615
 616 const EVP_PKEY_ASN1_METHOD dhx_asn1_meth = {
 617     EVP_PKEY_DHX,
 618     EVP_PKEY_DHX,
 619     0,
 620
 621     "X9.42 DH",
 622     "OpenSSL X9.42 DH method",
 623
 624     dh_pub_decode,
 625     dh_pub_encode,
 626     dh_pub_cmp,
 627     dh_public_print,
 628
 629     dh_priv_decode,
 630     dh_priv_encode,
 631     dh_private_print,
 632
 633     int_dh_size,
 634     dh_bits,
 635     dh_security_bits,
 636
 637     dh_param_decode,
 638     dh_param_encode,
 639     dh_missing_parameters,
 640     dh_copy_parameters,
 641     dh_cmp_parameters,
 642     dh_param_print,
 643     0,
 644
 645     int_dh_free,
 646     dh_pkey_ctrl
 647 };
 648
 649 #ifndef OPENSSL_NO_CMS
 650
 651 static int dh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
 652                               X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 653 {
 654     ASN1_OBJECT *aoid;
 655     int atype;
 656     void *aval;
 657     ASN1_INTEGER *public_key = NULL;
 658     int rv = 0;
 659     EVP_PKEY *pkpeer = NULL, *pk = NULL;
 660     DH *dhpeer = NULL;
 661     const unsigned char *p;
 662     int plen;
 663
 664     X509_ALGOR_get0(&aoid, &atype, &aval, alg);
 665     if (OBJ_obj2nid(aoid) != NID_dhpublicnumber)
 666         goto err;
 667     /* Only absent parameters allowed in RFC XXXX */
 668     if (atype != V_ASN1_UNDEF && atype == V_ASN1_NULL)
 669         goto err;
 670
 671     pk = EVP_PKEY_CTX_get0_pkey(pctx);
 672     if (!pk)
 673         goto err;
 674     if (pk->type != EVP_PKEY_DHX)
 675         goto err;
 676     /* Get parameters from parent key */
 677     dhpeer = DHparams_dup(pk->pkey.dh);
 678     /* We have parameters now set public key */
 679     plen = ASN1_STRING_length(pubkey);
 680     p = ASN1_STRING_data(pubkey);
 681     if (!p || !plen)
 682         goto err;
 683
 684     if ((public_key = d2i_ASN1_INTEGER(NULL, &p, plen)) == NULL) {
 685         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_DECODE_ERROR);
 686         goto err;
 687     }
 688
 689     /* We have parameters now set public key */
 690     if ((dhpeer->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
 691         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_BN_DECODE_ERROR);
 692         goto err;
 693     }
 694
 695     pkpeer = EVP_PKEY_new();
 696     if (!pkpeer)
 697         goto err;
 698     EVP_PKEY_assign(pkpeer, pk->ameth->pkey_id, dhpeer);
 699     dhpeer = NULL;
 700     if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
 701         rv = 1;
 702  err:
 703     ASN1_INTEGER_free(public_key);
 704     EVP_PKEY_free(pkpeer);
 705     DH_free(dhpeer);
 706     return rv;
 707 }
 708
 709 static int dh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 710 {
 711     int rv = 0;
 712
 713     X509_ALGOR *alg, *kekalg = NULL;
 714     ASN1_OCTET_STRING *ukm;
 715     const unsigned char *p;
 716     unsigned char *dukm = NULL;
 717     size_t dukmlen = 0;
 718     int keylen, plen;
 719     const EVP_CIPHER *kekcipher;
 720     EVP_CIPHER_CTX *kekctx;
 721
 722     if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
 723         goto err;
 724
 725     /*
 726      * For DH we only have one OID permissible. If ever any more get defined
 727      * we will need something cleverer.
 728      */
 729     if (OBJ_obj2nid(alg->algorithm) != NID_id_smime_alg_ESDH) {
 730         DHerr(DH_F_DH_CMS_SET_SHARED_INFO, DH_R_KDF_PARAMETER_ERROR);
 731         goto err;
 732     }
 733
 734     if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, EVP_PKEY_DH_KDF_X9_42) <= 0)
 735         goto err;
 736
 737     if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, EVP_sha1()) <= 0)
 738         goto err;
 739
 740     if (alg->parameter->type != V_ASN1_SEQUENCE)
 741         goto err;
 742
 743     p = alg->parameter->value.sequence->data;
 744     plen = alg->parameter->value.sequence->length;
 745     kekalg = d2i_X509_ALGOR(NULL, &p, plen);
 746     if (!kekalg)
 747         goto err;
 748     kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 749     if (!kekctx)
 750         goto err;
 751     kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
 752     if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
 753         goto err;
 754     if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
 755         goto err;
 756     if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
 757         goto err;
 758
 759     keylen = EVP_CIPHER_CTX_key_length(kekctx);
 760     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 761         goto err;
 762     /* Use OBJ_nid2obj to ensure we use built in OID that isn't freed */
 763     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx,
 764                                      OBJ_nid2obj(EVP_CIPHER_type(kekcipher)))
 765         <= 0)
 766         goto err;
 767
 768     if (ukm) {
 769         dukmlen = ASN1_STRING_length(ukm);
 770         dukm = BUF_memdup(ASN1_STRING_data(ukm), dukmlen);
 771         if (!dukm)
 772             goto err;
 773     }
 774
 775     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 776         goto err;
 777     dukm = NULL;
 778
 779     rv = 1;
 780  err:
 781     X509_ALGOR_free(kekalg);
 782     OPENSSL_free(dukm);
 783     return rv;
 784 }
 785
 786 static int dh_cms_decrypt(CMS_RecipientInfo *ri)
 787 {
 788     EVP_PKEY_CTX *pctx;
 789     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 790     if (!pctx)
 791         return 0;
 792     /* See if we need to set peer key */
 793     if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
 794         X509_ALGOR *alg;
 795         ASN1_BIT_STRING *pubkey;
 796         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
 797                                                  NULL, NULL, NULL))
 798             return 0;
 799         if (!alg || !pubkey)
 800             return 0;
 801         if (!dh_cms_set_peerkey(pctx, alg, pubkey)) {
 802             DHerr(DH_F_DH_CMS_DECRYPT, DH_R_PEER_KEY_ERROR);
 803             return 0;
 804         }
 805     }
 806     /* Set DH derivation parameters and initialise unwrap context */
 807     if (!dh_cms_set_shared_info(pctx, ri)) {
 808         DHerr(DH_F_DH_CMS_DECRYPT, DH_R_SHARED_INFO_ERROR);
 809         return 0;
 810     }
 811     return 1;
 812 }
 813
 814 static int dh_cms_encrypt(CMS_RecipientInfo *ri)
 815 {
 816     EVP_PKEY_CTX *pctx;
 817     EVP_PKEY *pkey;
 818     EVP_CIPHER_CTX *ctx;
 819     int keylen;
 820     X509_ALGOR *talg, *wrap_alg = NULL;
 821     ASN1_OBJECT *aoid;
 822     ASN1_BIT_STRING *pubkey;
 823     ASN1_STRING *wrap_str;
 824     ASN1_OCTET_STRING *ukm;
 825     unsigned char *penc = NULL, *dukm = NULL;
 826     int penclen;
 827     size_t dukmlen = 0;
 828     int rv = 0;
 829     int kdf_type, wrap_nid;
 830     const EVP_MD *kdf_md;
 831     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 832     if (!pctx)
 833         return 0;
 834     /* Get ephemeral key */
 835     pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 836     if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
 837                                              NULL, NULL, NULL))
 838         goto err;
 839     X509_ALGOR_get0(&aoid, NULL, NULL, talg);
 840     /* Is everything uninitialised? */
 841     if (aoid == OBJ_nid2obj(NID_undef)) {
 842         ASN1_INTEGER *pubk = BN_to_ASN1_INTEGER(pkey->pkey.dh->pub_key, NULL);
 843         if (!pubk)
 844             goto err;
 845         /* Set the key */
 846
 847         penclen = i2d_ASN1_INTEGER(pubk, &penc);
 848         ASN1_INTEGER_free(pubk);
 849         if (penclen <= 0)
 850             goto err;
 851         ASN1_STRING_set0(pubkey, penc, penclen);
 852         pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 853         pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 854
 855         penc = NULL;
 856         X509_ALGOR_set0(talg, OBJ_nid2obj(NID_dhpublicnumber),
 857                         V_ASN1_UNDEF, NULL);
 858     }
 859
 860     /* See if custom paraneters set */
 861     kdf_type = EVP_PKEY_CTX_get_dh_kdf_type(pctx);
 862     if (kdf_type <= 0)
 863         goto err;
 864     if (!EVP_PKEY_CTX_get_dh_kdf_md(pctx, &kdf_md))
 865         goto err;
 866
 867     if (kdf_type == EVP_PKEY_DH_KDF_NONE) {
 868         kdf_type = EVP_PKEY_DH_KDF_X9_42;
 869         if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, kdf_type) <= 0)
 870             goto err;
 871     } else if (kdf_type != EVP_PKEY_DH_KDF_X9_42)
 872         /* Unknown KDF */
 873         goto err;
 874     if (kdf_md == NULL) {
 875         /* Only SHA1 supported */
 876         kdf_md = EVP_sha1();
 877         if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, kdf_md) <= 0)
 878             goto err;
 879     } else if (EVP_MD_type(kdf_md) != NID_sha1)
 880         /* Unsupported digest */
 881         goto err;
 882
 883     if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
 884         goto err;
 885
 886     /* Get wrap NID */
 887     ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 888     wrap_nid = EVP_CIPHER_CTX_type(ctx);
 889     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx, OBJ_nid2obj(wrap_nid)) <= 0)
 890         goto err;
 891     keylen = EVP_CIPHER_CTX_key_length(ctx);
 892
 893     /* Package wrap algorithm in an AlgorithmIdentifier */
 894
 895     wrap_alg = X509_ALGOR_new();
 896     if (!wrap_alg)
 897         goto err;
 898     wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
 899     wrap_alg->parameter = ASN1_TYPE_new();
 900     if (!wrap_alg->parameter)
 901         goto err;
 902     if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
 903         goto err;
 904     if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
 905         ASN1_TYPE_free(wrap_alg->parameter);
 906         wrap_alg->parameter = NULL;
 907     }
 908
 909     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 910         goto err;
 911
 912     if (ukm) {
 913         dukmlen = ASN1_STRING_length(ukm);
 914         dukm = BUF_memdup(ASN1_STRING_data(ukm), dukmlen);
 915         if (!dukm)
 916             goto err;
 917     }
 918
 919     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 920         goto err;
 921     dukm = NULL;
 922
 923     /*
 924      * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
 925      * of another AlgorithmIdentifier.
 926      */
 927     penc = NULL;
 928     penclen = i2d_X509_ALGOR(wrap_alg, &penc);
 929     if (!penc || !penclen)
 930         goto err;
 931     wrap_str = ASN1_STRING_new();
 932     if (!wrap_str)
 933         goto err;
 934     ASN1_STRING_set0(wrap_str, penc, penclen);
 935     penc = NULL;
 936     X509_ALGOR_set0(talg, OBJ_nid2obj(NID_id_smime_alg_ESDH),
 937                     V_ASN1_SEQUENCE, wrap_str);
 938
 939     rv = 1;
 940
 941  err:
 942     OPENSSL_free(penc);
 943     X509_ALGOR_free(wrap_alg);
 944     return rv;
 945 }
 946
 947 #endif