crypto/crmf/crmf_lib.c

   1 /*-
   2  * Copyright 2007-2019 The OpenSSL Project Authors. All Rights Reserved.
   3  * Copyright Nokia 2007-2018
   4  * Copyright Siemens AG 2015-2019
   5  *
   6  * Licensed under the Apache License 2.0 (the "License").  You may not use
   7  * this file except in compliance with the License.  You can obtain a copy
   8  * in the file LICENSE in the source distribution or at
   9  * https://www.openssl.org/source/license.html
  10  *
  11  * CRMF implementation by Martin Peylo, Miikka Viljanen, and David von Oheimb.
  12  */
  13
  14 /*
  15  * This file contains the functions that handle the individual items inside
  16  * the CRMF structures
  17  */
  18
  19 /*
  20  * NAMING
  21  *
  22  * The 0 functions use the supplied structure pointer directly in the parent and
  23  * it will be freed up when the parent is freed.
  24  *
  25  * The 1 functions use a copy of the supplied structure pointer (or in some
  26  * cases increases its link count) in the parent and so both should be freed up.
  27  */
  28
  29 #include <openssl/asn1t.h>
  30
  31 #include "crmf_local.h"
  32 #include "internal/constant_time.h"
  33
  34 /* explicit #includes not strictly needed since implied by the above: */
  35 #include <openssl/crmf.h>
  36 #include <openssl/err.h>
  37 #include <openssl/evp.h>
  38
  39 /*-
  40  * atyp = Attribute Type
  41  * valt = Value Type
  42  * ctrlinf = "regCtrl" or "regInfo"
  43  */
  44 #define IMPLEMENT_CRMF_CTRL_FUNC(atyp, valt, ctrlinf)                     \
  45 int OSSL_CRMF_MSG_set1_##ctrlinf##_##atyp(OSSL_CRMF_MSG *msg,             \
  46                                           const valt *in)                 \
  47 {                                                                         \
  48     OSSL_CRMF_ATTRIBUTETYPEANDVALUE *atav = NULL;                         \
  49                                                                           \
  50     if (msg == NULL || in == NULL)                                       \
  51         goto err;                                                         \
  52     if ((atav = OSSL_CRMF_ATTRIBUTETYPEANDVALUE_new()) == NULL)           \
  53         goto err;                                                         \
  54     if ((atav->type = OBJ_nid2obj(NID_id_##ctrlinf##_##atyp)) == NULL)    \
  55         goto err;                                                         \
  56     if ((atav->value.atyp = valt##_dup(in)) == NULL)                      \
  57         goto err;                                                         \
  58     if (!OSSL_CRMF_MSG_push0_##ctrlinf(msg, atav))                        \
  59         goto err;                                                         \
  60     return 1;                                                             \
  61  err:                                                                     \
  62     OSSL_CRMF_ATTRIBUTETYPEANDVALUE_free(atav);                           \
  63     return 0;                                                             \
  64 }
  65
  66
  67 /*-
  68  * Pushes the given control attribute into the controls stack of a CertRequest
  69  * (section 6)
  70  * returns 1 on success, 0 on error
  71  */
  72 static int OSSL_CRMF_MSG_push0_regCtrl(OSSL_CRMF_MSG *crm,
  73                                        OSSL_CRMF_ATTRIBUTETYPEANDVALUE *ctrl)
  74 {
  75     int new = 0;
  76
  77     if (crm == NULL || crm->certReq == NULL || ctrl == NULL) {
  78         CRMFerr(CRMF_F_OSSL_CRMF_MSG_PUSH0_REGCTRL, CRMF_R_NULL_ARGUMENT);
  79         return 0;
  80     }
  81
  82     if (crm->certReq->controls == NULL) {
  83         crm->certReq->controls = sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_new_null();
  84         if (crm->certReq->controls == NULL)
  85             goto err;
  86         new = 1;
  87     }
  88     if (!sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_push(crm->certReq->controls, ctrl))
  89         goto err;
  90
  91     return 1;
  92  err:
  93     if (new != 0) {
  94         sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_free(crm->certReq->controls);
  95         crm->certReq->controls = NULL;
  96     }
  97     return 0;
  98 }
  99
 100 /* id-regCtrl-regToken Control (section 6.1) */
 101 IMPLEMENT_CRMF_CTRL_FUNC(regToken, ASN1_STRING, regCtrl)
 102
 103 /* id-regCtrl-authenticator Control (section 6.2) */
 104 #define ASN1_UTF8STRING_dup ASN1_STRING_dup
 105 IMPLEMENT_CRMF_CTRL_FUNC(authenticator, ASN1_UTF8STRING, regCtrl)
 106
 107 int OSSL_CRMF_MSG_set0_SinglePubInfo(OSSL_CRMF_SINGLEPUBINFO *spi,
 108                                      int method, GENERAL_NAME *nm)
 109 {
 110     if (spi == NULL
 111             || method < OSSL_CRMF_PUB_METHOD_DONTCARE
 112             || method > OSSL_CRMF_PUB_METHOD_LDAP) {
 113         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET0_SINGLEPUBINFO,
 114                 ERR_R_PASSED_INVALID_ARGUMENT);
 115         return 0;
 116     }
 117
 118     if (!ASN1_INTEGER_set(spi->pubMethod, method))
 119         return 0;
 120     GENERAL_NAME_free(spi->pubLocation);
 121     spi->pubLocation = nm;
 122     return 1;
 123 }
 124
 125 int
 126 OSSL_CRMF_MSG_PKIPublicationInfo_push0_SinglePubInfo(OSSL_CRMF_PKIPUBLICATIONINFO *pi,
 127                                                      OSSL_CRMF_SINGLEPUBINFO *spi)
 128 {
 129     if (pi == NULL || spi == NULL) {
 130         CRMFerr(CRMF_F_OSSL_CRMF_MSG_PKIPUBLICATIONINFO_PUSH0_SINGLEPUBINFO,
 131                 CRMF_R_NULL_ARGUMENT);
 132         return 0;
 133     }
 134     if (pi->pubInfos == NULL)
 135         pi->pubInfos = sk_OSSL_CRMF_SINGLEPUBINFO_new_null();
 136     if (pi->pubInfos == NULL)
 137         return 0;
 138
 139     return sk_OSSL_CRMF_SINGLEPUBINFO_push(pi->pubInfos, spi);
 140 }
 141
 142 int OSSL_CRMF_MSG_set_PKIPublicationInfo_action(OSSL_CRMF_PKIPUBLICATIONINFO *pi,
 143                                                 int action)
 144 {
 145     if (pi == NULL
 146             || action < OSSL_CRMF_PUB_ACTION_DONTPUBLISH
 147             || action > OSSL_CRMF_PUB_ACTION_PLEASEPUBLISH) {
 148         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET_PKIPUBLICATIONINFO_ACTION,
 149                 ERR_R_PASSED_INVALID_ARGUMENT);
 150         return 0;
 151     }
 152
 153     return ASN1_INTEGER_set(pi->action, action);
 154 }
 155
 156 /* id-regCtrl-pkiPublicationInfo Control (section 6.3) */
 157 IMPLEMENT_CRMF_CTRL_FUNC(pkiPublicationInfo, OSSL_CRMF_PKIPUBLICATIONINFO,
 158                          regCtrl)
 159
 160 /* id-regCtrl-oldCertID Control (section 6.5) from the given */
 161 IMPLEMENT_CRMF_CTRL_FUNC(oldCertID, OSSL_CRMF_CERTID, regCtrl)
 162
 163 OSSL_CRMF_CERTID *OSSL_CRMF_CERTID_gen(const X509_NAME *issuer,
 164                                        const ASN1_INTEGER *serial)
 165 {
 166     OSSL_CRMF_CERTID *cid = NULL;
 167
 168     if (issuer == NULL || serial == NULL) {
 169         CRMFerr(CRMF_F_OSSL_CRMF_CERTID_GEN, CRMF_R_NULL_ARGUMENT);
 170         return NULL;
 171     }
 172
 173     if ((cid = OSSL_CRMF_CERTID_new()) == NULL)
 174         goto err;
 175
 176     if (!X509_NAME_set(&cid->issuer->d.directoryName, issuer))
 177         goto err;
 178     cid->issuer->type = GEN_DIRNAME;
 179
 180     ASN1_INTEGER_free(cid->serialNumber);
 181     if ((cid->serialNumber = ASN1_INTEGER_dup(serial)) == NULL)
 182         goto err;
 183
 184     return cid;
 185
 186  err:
 187     OSSL_CRMF_CERTID_free(cid);
 188     return NULL;
 189 }
 190
 191 /*
 192  * id-regCtrl-protocolEncrKey Control (section 6.6)
 193  */
 194 IMPLEMENT_CRMF_CTRL_FUNC(protocolEncrKey, X509_PUBKEY, regCtrl)
 195
 196 /*-
 197  * Pushes the attribute given in regInfo in to the CertReqMsg->regInfo stack.
 198  * (section 7)
 199  * returns 1 on success, 0 on error
 200  */
 201 static int OSSL_CRMF_MSG_push0_regInfo(OSSL_CRMF_MSG *crm,
 202                                        OSSL_CRMF_ATTRIBUTETYPEANDVALUE *ri)
 203 {
 204     STACK_OF(OSSL_CRMF_ATTRIBUTETYPEANDVALUE) *info = NULL;
 205
 206     if (crm == NULL || ri == NULL) {
 207         CRMFerr(CRMF_F_OSSL_CRMF_MSG_PUSH0_REGINFO, CRMF_R_NULL_ARGUMENT);
 208         return 0;
 209     }
 210
 211     if (crm->regInfo == NULL)
 212         crm->regInfo = info = sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_new_null();
 213     if (crm->regInfo == NULL)
 214         goto err;
 215     if (!sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_push(crm->regInfo, ri))
 216         goto err;
 217     return 1;
 218
 219  err:
 220     if (info != NULL)
 221         crm->regInfo = NULL;
 222     sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_free(info);
 223     return 0;
 224 }
 225
 226 /* id-regInfo-utf8Pairs to regInfo (section 7.1) */
 227 IMPLEMENT_CRMF_CTRL_FUNC(utf8Pairs, ASN1_UTF8STRING, regInfo)
 228
 229 /* id-regInfo-certReq to regInfo (section 7.2) */
 230 IMPLEMENT_CRMF_CTRL_FUNC(certReq, OSSL_CRMF_CERTREQUEST, regInfo)
 231
 232
 233 /* retrieves the certificate template of crm */
 234 OSSL_CRMF_CERTTEMPLATE *OSSL_CRMF_MSG_get0_tmpl(const OSSL_CRMF_MSG *crm)
 235 {
 236     if (crm == NULL || crm->certReq == NULL) {
 237         CRMFerr(CRMF_F_OSSL_CRMF_MSG_GET0_TMPL, CRMF_R_NULL_ARGUMENT);
 238         return NULL;
 239     }
 240     return crm->certReq->certTemplate;
 241 }
 242
 243
 244 int OSSL_CRMF_MSG_set_validity(OSSL_CRMF_MSG *crm, time_t from, time_t to)
 245 {
 246     OSSL_CRMF_OPTIONALVALIDITY *vld = NULL;
 247     ASN1_TIME *from_asn = NULL;
 248     ASN1_TIME *to_asn = NULL;
 249     OSSL_CRMF_CERTTEMPLATE *tmpl = OSSL_CRMF_MSG_get0_tmpl(crm);
 250
 251     if (tmpl == NULL) { /* also crm == NULL implies this */
 252         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET_VALIDITY, CRMF_R_NULL_ARGUMENT);
 253         return 0;
 254     }
 255
 256     if (from != 0 && ((from_asn = ASN1_TIME_set(NULL, from)) == NULL))
 257         goto err;
 258     if (to != 0 && ((to_asn = ASN1_TIME_set(NULL, to)) == NULL))
 259         goto err;
 260     if ((vld = OSSL_CRMF_OPTIONALVALIDITY_new()) == NULL)
 261         goto err;
 262
 263     vld->notBefore = from_asn;
 264     vld->notAfter = to_asn;
 265
 266     tmpl->validity = vld;
 267
 268     return 1;
 269  err:
 270     ASN1_TIME_free(from_asn);
 271     ASN1_TIME_free(to_asn);
 272     return 0;
 273 }
 274
 275
 276 int OSSL_CRMF_MSG_set_certReqId(OSSL_CRMF_MSG *crm, int rid)
 277 {
 278     if (crm == NULL || crm->certReq == NULL || crm->certReq->certReqId == NULL) {
 279         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET_CERTREQID, CRMF_R_NULL_ARGUMENT);
 280         return 0;
 281     }
 282
 283     return ASN1_INTEGER_set(crm->certReq->certReqId, rid);
 284 }
 285
 286 /* get ASN.1 encoded integer, return -1 on error */
 287 static int crmf_asn1_get_int(const ASN1_INTEGER *a)
 288 {
 289     int64_t res;
 290
 291     if (!ASN1_INTEGER_get_int64(&res, a)) {
 292         CRMFerr(0, ASN1_R_INVALID_NUMBER);
 293         return -1;
 294     }
 295     if (res < INT_MIN) {
 296         CRMFerr(0, ASN1_R_TOO_SMALL);
 297         return -1;
 298     }
 299     if (res > INT_MAX) {
 300         CRMFerr(0, ASN1_R_TOO_LARGE);
 301         return -1;
 302     }
 303     return (int)res;
 304 }
 305
 306 int OSSL_CRMF_MSG_get_certReqId(const OSSL_CRMF_MSG *crm)
 307 {
 308     if (crm == NULL || /* not really needed: */ crm->certReq == NULL) {
 309         CRMFerr(CRMF_F_OSSL_CRMF_MSG_GET_CERTREQID, CRMF_R_NULL_ARGUMENT);
 310         return -1;
 311     }
 312     return crmf_asn1_get_int(crm->certReq->certReqId);
 313 }
 314
 315
 316 int OSSL_CRMF_MSG_set0_extensions(OSSL_CRMF_MSG *crm,
 317                                   X509_EXTENSIONS *exts)
 318 {
 319     OSSL_CRMF_CERTTEMPLATE *tmpl = OSSL_CRMF_MSG_get0_tmpl(crm);
 320
 321     if (tmpl == NULL) { /* also crm == NULL implies this */
 322         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET0_EXTENSIONS, CRMF_R_NULL_ARGUMENT);
 323         return 0;
 324     }
 325
 326     if (sk_X509_EXTENSION_num(exts) == 0) {
 327         sk_X509_EXTENSION_free(exts);
 328         exts = NULL; /* do not include empty extensions list */
 329     }
 330
 331     sk_X509_EXTENSION_pop_free(tmpl->extensions, X509_EXTENSION_free);
 332     tmpl->extensions = exts;
 333     return 1;
 334 }
 335
 336
 337 int OSSL_CRMF_MSG_push0_extension(OSSL_CRMF_MSG *crm,
 338                                   X509_EXTENSION *ext)
 339 {
 340     int new = 0;
 341     OSSL_CRMF_CERTTEMPLATE *tmpl = OSSL_CRMF_MSG_get0_tmpl(crm);
 342
 343     if (tmpl == NULL || ext == NULL) { /* also crm == NULL implies this */
 344         CRMFerr(CRMF_F_OSSL_CRMF_MSG_PUSH0_EXTENSION, CRMF_R_NULL_ARGUMENT);
 345         return 0;
 346     }
 347
 348     if (tmpl->extensions == NULL) {
 349         if ((tmpl->extensions = sk_X509_EXTENSION_new_null()) == NULL)
 350             goto err;
 351         new = 1;
 352     }
 353
 354     if (!sk_X509_EXTENSION_push(tmpl->extensions, ext))
 355         goto err;
 356     return 1;
 357  err:
 358     if (new != 0) {
 359         sk_X509_EXTENSION_free(tmpl->extensions);
 360         tmpl->extensions = NULL;
 361     }
 362     return 0;
 363 }
 364
 365 /* TODO: support cases 1+2 (besides case 3) defined in RFC 4211, section 4.1. */
 366 static int CRMF_poposigningkey_init(OSSL_CRMF_POPOSIGNINGKEY *ps,
 367                                     OSSL_CRMF_CERTREQUEST *cr,
 368                                     EVP_PKEY *pkey, int dgst)
 369 {
 370     int ret = 0;
 371     EVP_MD *fetched_md = NULL;
 372     const EVP_MD *md = EVP_get_digestbynid(dgst);
 373
 374     if (ps == NULL || cr == NULL || pkey == NULL) {
 375         CRMFerr(CRMF_F_CRMF_POPOSIGNINGKEY_INIT, CRMF_R_NULL_ARGUMENT);
 376         return 0;
 377     }
 378
 379     /* If we didn't find legacy MD, we try an implicit fetch */
 380     if (md == NULL)
 381         md = fetched_md = EVP_MD_fetch(NULL, OBJ_nid2sn(dgst), NULL);
 382
 383     if (md == NULL) {
 384         CRMFerr(CRMF_F_CRMF_POPOSIGNINGKEY_INIT,
 385                 CRMF_R_UNSUPPORTED_ALG_FOR_POPSIGNINGKEY);
 386         return 0;
 387     }
 388
 389     ret = ASN1_item_sign(ASN1_ITEM_rptr(OSSL_CRMF_CERTREQUEST),
 390                          ps->algorithmIdentifier, NULL, ps->signature,
 391                          cr, pkey, md);
 392
 393     EVP_MD_free(fetched_md);
 394     return ret;
 395 }
 396
 397
 398 int OSSL_CRMF_MSG_create_popo(OSSL_CRMF_MSG *crm, EVP_PKEY *pkey,
 399                               int dgst, int ppmtd)
 400 {
 401     OSSL_CRMF_POPO *pp = NULL;
 402     ASN1_INTEGER *tag = NULL;
 403
 404     if (crm == NULL || (ppmtd == OSSL_CRMF_POPO_SIGNATURE && pkey == NULL)) {
 405         CRMFerr(CRMF_F_OSSL_CRMF_MSG_CREATE_POPO, CRMF_R_NULL_ARGUMENT);
 406         return 0;
 407     }
 408
 409     if (ppmtd == OSSL_CRMF_POPO_NONE)
 410         goto end;
 411     if ((pp = OSSL_CRMF_POPO_new()) == NULL)
 412         goto err;
 413     pp->type = ppmtd;
 414
 415     switch (ppmtd) {
 416     case OSSL_CRMF_POPO_RAVERIFIED:
 417         if ((pp->value.raVerified = ASN1_NULL_new()) == NULL)
 418             goto err;
 419         break;
 420
 421     case OSSL_CRMF_POPO_SIGNATURE:
 422         {
 423             OSSL_CRMF_POPOSIGNINGKEY *ps = OSSL_CRMF_POPOSIGNINGKEY_new();
 424             if (ps == NULL
 425                     || !CRMF_poposigningkey_init(ps, crm->certReq, pkey, dgst)) {
 426                 OSSL_CRMF_POPOSIGNINGKEY_free(ps);
 427                 goto err;
 428             }
 429             pp->value.signature = ps;
 430         }
 431         break;
 432
 433     case OSSL_CRMF_POPO_KEYENC:
 434         if ((pp->value.keyEncipherment = OSSL_CRMF_POPOPRIVKEY_new()) == NULL)
 435             goto err;
 436         tag = ASN1_INTEGER_new();
 437         pp->value.keyEncipherment->type =
 438             OSSL_CRMF_POPOPRIVKEY_SUBSEQUENTMESSAGE;
 439         pp->value.keyEncipherment->value.subsequentMessage = tag;
 440         if (tag == NULL
 441                 || !ASN1_INTEGER_set(tag, OSSL_CRMF_SUBSEQUENTMESSAGE_ENCRCERT))
 442             goto err;
 443         break;
 444
 445     default:
 446         CRMFerr(CRMF_F_OSSL_CRMF_MSG_CREATE_POPO,
 447                 CRMF_R_UNSUPPORTED_METHOD_FOR_CREATING_POPO);
 448         goto err;
 449     }
 450
 451  end:
 452     OSSL_CRMF_POPO_free(crm->popo);
 453     crm->popo = pp;
 454
 455     return 1;
 456  err:
 457     OSSL_CRMF_POPO_free(pp);
 458     return 0;
 459 }
 460
 461 /* returns 0 for equal, -1 for a < b or error on a, 1 for a > b or error on b */
 462 static int X509_PUBKEY_cmp(X509_PUBKEY *a, X509_PUBKEY *b)
 463 {
 464     X509_ALGOR *algA = NULL, *algB = NULL;
 465     int res = 0;
 466
 467     if (a == b)
 468         return 0;
 469     if (a == NULL || !X509_PUBKEY_get0_param(NULL, NULL, NULL, &algA, a)
 470             || algA == NULL)
 471         return -1;
 472     if (b == NULL || !X509_PUBKEY_get0_param(NULL, NULL, NULL, &algB, b)
 473             || algB == NULL)
 474         return 1;
 475     if ((res = X509_ALGOR_cmp(algA, algB)) != 0)
 476         return res;
 477     return EVP_PKEY_cmp(X509_PUBKEY_get0(a), X509_PUBKEY_get0(b));
 478 }
 479
 480 /* verifies the Proof-of-Possession of the request with the given rid in reqs */
 481 int OSSL_CRMF_MSGS_verify_popo(const OSSL_CRMF_MSGS *reqs,
 482                                int rid, int acceptRAVerified)
 483 {
 484     OSSL_CRMF_MSG *req = NULL;
 485     X509_PUBKEY *pubkey = NULL;
 486     OSSL_CRMF_POPOSIGNINGKEY *sig = NULL;
 487
 488     if (reqs == NULL
 489             || (req = sk_OSSL_CRMF_MSG_value(reqs, rid)) == NULL
 490             || req->popo == NULL) {
 491         CRMFerr(CRMF_F_OSSL_CRMF_MSGS_VERIFY_POPO,
 492                 CRMF_R_NULL_ARGUMENT);
 493         return 0;
 494     }
 495
 496     switch (req->popo->type) {
 497     case OSSL_CRMF_POPO_RAVERIFIED:
 498         if (!acceptRAVerified) {
 499             CRMFerr(0, CRMF_R_POPO_RAVERIFIED_NOT_ACCEPTED);
 500             return 0;
 501         }
 502         break;
 503     case OSSL_CRMF_POPO_SIGNATURE:
 504         pubkey = req->certReq->certTemplate->publicKey;
 505         if (pubkey == NULL) {
 506             CRMFerr(0, CRMF_R_POPO_MISSING_PUBLIC_KEY);
 507             return 0;
 508         }
 509         sig = req->popo->value.signature;
 510         if (sig->poposkInput != NULL) {
 511             /*
 512              * According to RFC 4211: publicKey contains a copy of
 513              * the public key from the certificate template. This MUST be
 514              * exactly the same value as contained in the certificate template.
 515              */
 516             if (sig->poposkInput->publicKey == NULL) {
 517                 CRMFerr(0, CRMF_R_POPO_MISSING_PUBLIC_KEY);
 518                 return 0;
 519             }
 520             if (X509_PUBKEY_cmp(pubkey, sig->poposkInput->publicKey) != 0) {
 521                 CRMFerr(0, CRMF_R_POPO_INCONSISTENT_PUBLIC_KEY);
 522                 return 0;
 523             }
 524             /*
 525              * TODO check the contents of the authInfo sub-field,
 526              * see RFC 4211 https://tools.ietf.org/html/rfc4211#section-4.1
 527              */
 528             if (ASN1_item_verify(ASN1_ITEM_rptr(OSSL_CRMF_POPOSIGNINGKEYINPUT),
 529                                  sig->algorithmIdentifier, sig->signature,
 530                                  sig->poposkInput,
 531                                  X509_PUBKEY_get0(pubkey)) < 1)
 532                 return 0;
 533         } else {
 534             if (req->certReq->certTemplate->subject == NULL) {
 535                 CRMFerr(0, CRMF_R_POPO_MISSING_SUBJECT);
 536                 return 0;
 537             }
 538             if (ASN1_item_verify(ASN1_ITEM_rptr(OSSL_CRMF_CERTREQUEST),
 539                                  sig->algorithmIdentifier, sig->signature,
 540                                  req->certReq, X509_PUBKEY_get0(pubkey)) < 1)
 541                 return 0;
 542         }
 543         break;
 544     case OSSL_CRMF_POPO_KEYENC:
 545         /*
 546          * TODO: when OSSL_CMP_certrep_new() supports encrypted certs,
 547          * return 1 if the type of req->popo->value.keyEncipherment
 548          * is OSSL_CRMF_POPOPRIVKEY_SUBSEQUENTMESSAGE and
 549          * its value.subsequentMessage == OSSL_CRMF_SUBSEQUENTMESSAGE_ENCRCERT
 550          */
 551     case OSSL_CRMF_POPO_KEYAGREE:
 552     default:
 553         CRMFerr(CRMF_F_OSSL_CRMF_MSGS_VERIFY_POPO,
 554                 CRMF_R_UNSUPPORTED_POPO_METHOD);
 555         return 0;
 556     }
 557     return 1;
 558 }
 559
 560 /* retrieves the serialNumber of the given cert template or NULL on error */
 561 ASN1_INTEGER
 562 *OSSL_CRMF_CERTTEMPLATE_get0_serialNumber(const OSSL_CRMF_CERTTEMPLATE *tmpl)
 563 {
 564     return tmpl != NULL ? tmpl->serialNumber : NULL;
 565 }
 566
 567 /* retrieves the issuer name of the given cert template or NULL on error */
 568 X509_NAME
 569 *OSSL_CRMF_CERTTEMPLATE_get0_issuer(const OSSL_CRMF_CERTTEMPLATE *tmpl)
 570 {
 571     return tmpl != NULL ? tmpl->issuer : NULL;
 572 }
 573
 574 /* retrieves the issuer name of the given CertId or NULL on error */
 575 X509_NAME *OSSL_CRMF_CERTID_get0_issuer(const OSSL_CRMF_CERTID *cid)
 576 {
 577     return cid != NULL && cid->issuer->type == GEN_DIRNAME ?
 578         cid->issuer->d.directoryName : NULL;
 579 }
 580
 581 /* retrieves the serialNumber of the given CertId or NULL on error */
 582 ASN1_INTEGER *OSSL_CRMF_CERTID_get0_serialNumber(const OSSL_CRMF_CERTID *cid)
 583 {
 584     return cid != NULL ? cid->serialNumber : NULL;
 585 }
 586
 587 /*-
 588  * fill in certificate template.
 589  * Any value argument that is NULL will leave the respective field unchanged.
 590  */
 591 int OSSL_CRMF_CERTTEMPLATE_fill(OSSL_CRMF_CERTTEMPLATE *tmpl,
 592                                 EVP_PKEY *pubkey,
 593                                 const X509_NAME *subject,
 594                                 const X509_NAME *issuer,
 595                                 const ASN1_INTEGER *serial)
 596 {
 597     if (tmpl == NULL) {
 598         CRMFerr(CRMF_F_OSSL_CRMF_CERTTEMPLATE_FILL, CRMF_R_NULL_ARGUMENT);
 599         return 0;
 600     }
 601     if (subject != NULL && !X509_NAME_set(&tmpl->subject, subject))
 602         return 0;
 603     if (issuer != NULL && !X509_NAME_set(&tmpl->issuer, issuer))
 604         return 0;
 605     if (serial != NULL) {
 606         ASN1_INTEGER_free(tmpl->serialNumber);
 607         if ((tmpl->serialNumber = ASN1_INTEGER_dup(serial)) == NULL)
 608             return 0;
 609     }
 610     if (pubkey != NULL && !X509_PUBKEY_set(&tmpl->publicKey, pubkey))
 611         return 0;
 612     return 1;
 613 }
 614
 615
 616 /*-
 617  * Decrypts the certificate in the given encryptedValue using private key pkey.
 618  * This is needed for the indirect PoP method as in RFC 4210 section 5.2.8.2.
 619  *
 620  * returns a pointer to the decrypted certificate
 621  * returns NULL on error or if no certificate available
 622  */
 623 X509 *OSSL_CRMF_ENCRYPTEDVALUE_get1_encCert(const OSSL_CRMF_ENCRYPTEDVALUE *ecert,
 624                                             EVP_PKEY *pkey)
 625 {
 626     X509 *cert = NULL; /* decrypted certificate */
 627     EVP_CIPHER_CTX *evp_ctx = NULL; /* context for symmetric encryption */
 628     unsigned char *ek = NULL; /* decrypted symmetric encryption key */
 629     size_t eksize = 0; /* size of decrypted symmetric encryption key */
 630     const EVP_CIPHER *cipher = NULL; /* used cipher */
 631     int cikeysize = 0; /* key size from cipher */
 632     unsigned char *iv = NULL; /* initial vector for symmetric encryption */
 633     unsigned char *outbuf = NULL; /* decryption output buffer */
 634     const unsigned char *p = NULL; /* needed for decoding ASN1 */
 635     int symmAlg = 0; /* NIDs for symmetric algorithm */
 636     int n, outlen = 0;
 637     EVP_PKEY_CTX *pkctx = NULL; /* private key context */
 638
 639     if (ecert == NULL || ecert->symmAlg == NULL || ecert->encSymmKey == NULL
 640             || ecert->encValue == NULL || pkey == NULL) {
 641         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 642                 CRMF_R_NULL_ARGUMENT);
 643         return NULL;
 644     }
 645     if ((symmAlg = OBJ_obj2nid(ecert->symmAlg->algorithm)) == 0) {
 646         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 647                 CRMF_R_UNSUPPORTED_CIPHER);
 648         return NULL;
 649     }
 650     /* select symmetric cipher based on algorithm given in message */
 651     if ((cipher = EVP_get_cipherbynid(symmAlg)) == NULL) {
 652         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 653                 CRMF_R_UNSUPPORTED_CIPHER);
 654         goto end;
 655     }
 656     cikeysize = EVP_CIPHER_key_length(cipher);
 657     /* first the symmetric key needs to be decrypted */
 658     pkctx = EVP_PKEY_CTX_new(pkey, NULL);
 659     if (pkctx != NULL && EVP_PKEY_decrypt_init(pkctx)) {
 660         ASN1_BIT_STRING *encKey = ecert->encSymmKey;
 661         size_t failure;
 662         int retval;
 663
 664         if (EVP_PKEY_decrypt(pkctx, NULL, &eksize,
 665                              encKey->data, encKey->length) <= 0
 666                 || (ek = OPENSSL_malloc(eksize)) == NULL)
 667             goto end;
 668         retval = EVP_PKEY_decrypt(pkctx, ek, &eksize,
 669                                   encKey->data, encKey->length);
 670         ERR_clear_error(); /* error state may have sensitive information */
 671         failure = ~constant_time_is_zero_s(constant_time_msb(retval)
 672                                            | constant_time_is_zero(retval));
 673         failure |= ~constant_time_eq_s(eksize, (size_t)cikeysize);
 674         if (failure) {
 675             CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 676                     CRMF_R_ERROR_DECRYPTING_SYMMETRIC_KEY);
 677             goto end;
 678         }
 679     } else {
 680         goto end;
 681     }
 682     if ((iv = OPENSSL_malloc(EVP_CIPHER_iv_length(cipher))) == NULL)
 683         goto end;
 684     if (ASN1_TYPE_get_octetstring(ecert->symmAlg->parameter, iv,
 685                                   EVP_CIPHER_iv_length(cipher))
 686         != EVP_CIPHER_iv_length(cipher)) {
 687         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 688                 CRMF_R_MALFORMED_IV);
 689         goto end;
 690     }
 691
 692     /*
 693      * d2i_X509 changes the given pointer, so use p for decoding the message and
 694      * keep the original pointer in outbuf so the memory can be freed later
 695      */
 696     if ((p = outbuf = OPENSSL_malloc(ecert->encValue->length +
 697                                      EVP_CIPHER_block_size(cipher))) == NULL
 698             || (evp_ctx = EVP_CIPHER_CTX_new()) == NULL)
 699         goto end;
 700     EVP_CIPHER_CTX_set_padding(evp_ctx, 0);
 701
 702     if (!EVP_DecryptInit(evp_ctx, cipher, ek, iv)
 703             || !EVP_DecryptUpdate(evp_ctx, outbuf, &outlen,
 704                                   ecert->encValue->data,
 705                                   ecert->encValue->length)
 706             || !EVP_DecryptFinal(evp_ctx, outbuf + outlen, &n)) {
 707         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 708                 CRMF_R_ERROR_DECRYPTING_CERTIFICATE);
 709         goto end;
 710     }
 711     outlen += n;
 712
 713     /* convert decrypted certificate from DER to internal ASN.1 structure */
 714     if ((cert = d2i_X509(NULL, &p, outlen)) == NULL) {
 715         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 716                 CRMF_R_ERROR_DECODING_CERTIFICATE);
 717     }
 718  end:
 719     EVP_PKEY_CTX_free(pkctx);
 720     OPENSSL_free(outbuf);
 721     EVP_CIPHER_CTX_free(evp_ctx);
 722     OPENSSL_clear_free(ek, eksize);
 723     OPENSSL_free(iv);
 724     return cert;
 725 }