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 OSSL_CRMF_MSG_PKIPublicationInfo_push0_SinglePubInfo(
 126                                  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(
 143                                  OSSL_CRMF_PKIPUBLICATIONINFO *pi, 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   */
 195 IMPLEMENT_CRMF_CTRL_FUNC(protocolEncrKey, X509_PUBKEY, regCtrl)
 196
 197 /*-
 198  * Pushes the attribute given in regInfo in to the CertReqMsg->regInfo stack.
 199  * (section 7)
 200  * returns 1 on success, 0 on error
 201  */
 202 static int OSSL_CRMF_MSG_push0_regInfo(OSSL_CRMF_MSG *crm,
 203                                        OSSL_CRMF_ATTRIBUTETYPEANDVALUE *ri)
 204 {
 205     STACK_OF(OSSL_CRMF_ATTRIBUTETYPEANDVALUE) *info = NULL;
 206
 207     if (crm == NULL || ri == NULL) {
 208         CRMFerr(CRMF_F_OSSL_CRMF_MSG_PUSH0_REGINFO, CRMF_R_NULL_ARGUMENT);
 209         return 0;
 210     }
 211
 212     if (crm->regInfo == NULL)
 213         crm->regInfo = info = sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_new_null();
 214     if (crm->regInfo == NULL)
 215         goto err;
 216     if (!sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_push(crm->regInfo, ri))
 217         goto err;
 218     return 1;
 219
 220  err:
 221     if (info != NULL)
 222         crm->regInfo = NULL;
 223     sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_free(info);
 224     return 0;
 225 }
 226
 227 /* id-regInfo-utf8Pairs to regInfo (section 7.1) */
 228 IMPLEMENT_CRMF_CTRL_FUNC(utf8Pairs, ASN1_UTF8STRING, regInfo)
 229
 230 /* id-regInfo-certReq to regInfo (section 7.2) */
 231 IMPLEMENT_CRMF_CTRL_FUNC(certReq, OSSL_CRMF_CERTREQUEST, regInfo)
 232
 233
 234 /* retrieves the certificate template of crm */
 235 OSSL_CRMF_CERTTEMPLATE *OSSL_CRMF_MSG_get0_tmpl(const OSSL_CRMF_MSG *crm)
 236 {
 237     if (crm == NULL || crm->certReq == NULL) {
 238         CRMFerr(CRMF_F_OSSL_CRMF_MSG_GET0_TMPL, CRMF_R_NULL_ARGUMENT);
 239         return NULL;
 240     }
 241     return crm->certReq->certTemplate;
 242 }
 243
 244
 245 int OSSL_CRMF_MSG_set_validity(OSSL_CRMF_MSG *crm, time_t from, time_t to)
 246 {
 247     OSSL_CRMF_OPTIONALVALIDITY *vld = NULL;
 248     ASN1_TIME *from_asn = NULL;
 249     ASN1_TIME *to_asn = NULL;
 250     OSSL_CRMF_CERTTEMPLATE *tmpl = OSSL_CRMF_MSG_get0_tmpl(crm);
 251
 252     if (tmpl == NULL) { /* also crm == NULL implies this */
 253         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET_VALIDITY, CRMF_R_NULL_ARGUMENT);
 254         return 0;
 255     }
 256
 257     if (from != 0 && ((from_asn = ASN1_TIME_set(NULL, from)) == NULL))
 258         goto err;
 259     if (to != 0 && ((to_asn = ASN1_TIME_set(NULL, to)) == NULL))
 260         goto err;
 261     if ((vld = OSSL_CRMF_OPTIONALVALIDITY_new()) == NULL)
 262         goto err;
 263
 264     vld->notBefore = from_asn;
 265     vld->notAfter = to_asn;
 266
 267     tmpl->validity = vld;
 268
 269     return 1;
 270  err:
 271     ASN1_TIME_free(from_asn);
 272     ASN1_TIME_free(to_asn);
 273     return 0;
 274 }
 275
 276
 277 int OSSL_CRMF_MSG_set_certReqId(OSSL_CRMF_MSG *crm, int rid)
 278 {
 279     if (crm == NULL || crm->certReq == NULL || crm->certReq->certReqId == NULL) {
 280         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET_CERTREQID, CRMF_R_NULL_ARGUMENT);
 281         return 0;
 282     }
 283
 284     return ASN1_INTEGER_set(crm->certReq->certReqId, rid);
 285 }
 286
 287 /* get ASN.1 encoded integer, return -1 on error */
 288 static int crmf_asn1_get_int(const ASN1_INTEGER *a)
 289 {
 290     int64_t res;
 291
 292     if (!ASN1_INTEGER_get_int64(&res, a)) {
 293         CRMFerr(0, ASN1_R_INVALID_NUMBER);
 294         return -1;
 295     }
 296     if (res < INT_MIN) {
 297         CRMFerr(0, ASN1_R_TOO_SMALL);
 298         return -1;
 299     }
 300     if (res > INT_MAX) {
 301         CRMFerr(0, ASN1_R_TOO_LARGE);
 302         return -1;
 303     }
 304     return (int)res;
 305 }
 306
 307 int OSSL_CRMF_MSG_get_certReqId(OSSL_CRMF_MSG *crm)
 308 {
 309     if (crm == NULL || /* not really needed: */ crm->certReq == NULL) {
 310         CRMFerr(CRMF_F_OSSL_CRMF_MSG_GET_CERTREQID, CRMF_R_NULL_ARGUMENT);
 311         return -1;
 312     }
 313     return crmf_asn1_get_int(crm->certReq->certReqId);
 314 }
 315
 316
 317 int OSSL_CRMF_MSG_set0_extensions(OSSL_CRMF_MSG *crm,
 318                                   X509_EXTENSIONS *exts)
 319 {
 320     OSSL_CRMF_CERTTEMPLATE *tmpl = OSSL_CRMF_MSG_get0_tmpl(crm);
 321
 322     if (tmpl == NULL) { /* also crm == NULL implies this */
 323         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET0_EXTENSIONS, CRMF_R_NULL_ARGUMENT);
 324         return 0;
 325     }
 326
 327     if (sk_X509_EXTENSION_num(exts) == 0) {
 328         sk_X509_EXTENSION_free(exts);
 329         exts = NULL; /* do not include empty extensions list */
 330     }
 331
 332     sk_X509_EXTENSION_pop_free(tmpl->extensions, X509_EXTENSION_free);
 333     tmpl->extensions = exts;
 334     return 1;
 335 }
 336
 337
 338 int OSSL_CRMF_MSG_push0_extension(OSSL_CRMF_MSG *crm,
 339                                   X509_EXTENSION *ext)
 340 {
 341     int new = 0;
 342     OSSL_CRMF_CERTTEMPLATE *tmpl = OSSL_CRMF_MSG_get0_tmpl(crm);
 343
 344     if (tmpl == NULL || ext == NULL) { /* also crm == NULL implies this */
 345         CRMFerr(CRMF_F_OSSL_CRMF_MSG_PUSH0_EXTENSION, CRMF_R_NULL_ARGUMENT);
 346         return 0;
 347     }
 348
 349     if (tmpl->extensions == NULL) {
 350         if ((tmpl->extensions = sk_X509_EXTENSION_new_null()) == NULL)
 351             goto err;
 352         new = 1;
 353     }
 354
 355     if (!sk_X509_EXTENSION_push(tmpl->extensions, ext))
 356         goto err;
 357     return 1;
 358  err:
 359     if (new != 0) {
 360         sk_X509_EXTENSION_free(tmpl->extensions);
 361         tmpl->extensions = NULL;
 362     }
 363     return 0;
 364 }
 365
 366 /* TODO: support cases 1+2 (besides case 3) defined in RFC 4211, section 4.1. */
 367 static int CRMF_poposigningkey_init(OSSL_CRMF_POPOSIGNINGKEY *ps,
 368                                     OSSL_CRMF_CERTREQUEST *cr,
 369                                     EVP_PKEY *pkey, int dgst)
 370 {
 371     int len;
 372     size_t crlen;
 373     size_t siglen;
 374     unsigned char *crder = NULL, *sig = NULL;
 375     int alg_nid = 0;
 376     int md_nid = 0;
 377     const EVP_MD *alg = NULL;
 378     EVP_MD_CTX *ctx = NULL;
 379     int ret = 0;
 380
 381     if (ps == NULL || cr == NULL || pkey == NULL) {
 382         CRMFerr(CRMF_F_CRMF_POPOSIGNINGKEY_INIT, CRMF_R_NULL_ARGUMENT);
 383         return 0;
 384     }
 385
 386     /* OpenSSL defaults all bit strings to be encoded as ASN.1 NamedBitList */
 387     ps->signature->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 388     ps->signature->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 389
 390     len = i2d_OSSL_CRMF_CERTREQUEST(cr, &crder);
 391     if (len < 0 || crder == NULL) {
 392         CRMFerr(CRMF_F_CRMF_POPOSIGNINGKEY_INIT, CRMF_R_ERROR);
 393         goto err;
 394     }
 395     crlen = (size_t)len;
 396
 397     if (!OBJ_find_sigid_by_algs(&alg_nid, dgst, EVP_PKEY_id(pkey))) {
 398         CRMFerr(CRMF_F_CRMF_POPOSIGNINGKEY_INIT,
 399                 CRMF_R_UNSUPPORTED_ALG_FOR_POPSIGNINGKEY);
 400         goto err;
 401     }
 402     if (!OBJ_find_sigid_algs(alg_nid, &md_nid, NULL)
 403             || (alg = EVP_get_digestbynid(md_nid)) == NULL) {
 404         CRMFerr(CRMF_F_CRMF_POPOSIGNINGKEY_INIT,
 405                 CRMF_R_UNSUPPORTED_ALG_FOR_POPSIGNINGKEY);
 406         goto err;
 407     }
 408     if (!X509_ALGOR_set0(ps->algorithmIdentifier, OBJ_nid2obj(alg_nid),
 409                          V_ASN1_NULL, NULL)
 410             || (ctx = EVP_MD_CTX_new()) == NULL
 411             || EVP_DigestSignInit(ctx, NULL, alg, NULL, pkey) <= 0
 412             || EVP_DigestSignUpdate(ctx, crder, crlen) <= 0
 413             || EVP_DigestSignFinal(ctx, NULL, &siglen) <= 0) {
 414         CRMFerr(CRMF_F_CRMF_POPOSIGNINGKEY_INIT, CRMF_R_ERROR);
 415         goto err;
 416     }
 417     if ((sig = OPENSSL_malloc(siglen)) == NULL)
 418         goto err;
 419     if (EVP_DigestSignFinal(ctx, sig, &siglen) <= 0
 420             || !ASN1_BIT_STRING_set(ps->signature, sig, siglen)) {
 421         CRMFerr(CRMF_F_CRMF_POPOSIGNINGKEY_INIT, CRMF_R_ERROR);
 422         goto err;
 423     }
 424     ret = 1;
 425
 426  err:
 427     OPENSSL_free(crder);
 428     EVP_MD_CTX_free(ctx);
 429     OPENSSL_free(sig);
 430     return ret;
 431 }
 432
 433
 434 int OSSL_CRMF_MSG_create_popo(OSSL_CRMF_MSG *crm, EVP_PKEY *pkey,
 435                               int dgst, int ppmtd)
 436 {
 437     OSSL_CRMF_POPO *pp = NULL;
 438     ASN1_INTEGER *tag = NULL;
 439
 440     if (crm == NULL || (ppmtd == OSSL_CRMF_POPO_SIGNATURE && pkey == NULL)) {
 441         CRMFerr(CRMF_F_OSSL_CRMF_MSG_CREATE_POPO, CRMF_R_NULL_ARGUMENT);
 442         return 0;
 443     }
 444
 445     if (ppmtd == OSSL_CRMF_POPO_NONE)
 446         goto end;
 447     if ((pp = OSSL_CRMF_POPO_new()) == NULL)
 448         goto err;
 449     pp->type = ppmtd;
 450
 451     switch (ppmtd) {
 452     case OSSL_CRMF_POPO_RAVERIFIED:
 453         if ((pp->value.raVerified = ASN1_NULL_new()) == NULL)
 454             goto err;
 455         break;
 456
 457     case OSSL_CRMF_POPO_SIGNATURE:
 458         {
 459             OSSL_CRMF_POPOSIGNINGKEY *ps = OSSL_CRMF_POPOSIGNINGKEY_new();
 460             if (ps == NULL
 461                     || !CRMF_poposigningkey_init(ps, crm->certReq, pkey, dgst)){
 462                 OSSL_CRMF_POPOSIGNINGKEY_free(ps);
 463                 goto err;
 464             }
 465             pp->value.signature = ps;
 466         }
 467         break;
 468
 469     case OSSL_CRMF_POPO_KEYENC:
 470         if ((pp->value.keyEncipherment = OSSL_CRMF_POPOPRIVKEY_new()) == NULL)
 471             goto err;
 472         tag = ASN1_INTEGER_new();
 473         pp->value.keyEncipherment->type =
 474             OSSL_CRMF_POPOPRIVKEY_SUBSEQUENTMESSAGE;
 475         pp->value.keyEncipherment->value.subsequentMessage = tag;
 476         if (tag == NULL
 477                 || !ASN1_INTEGER_set(tag, OSSL_CRMF_SUBSEQUENTMESSAGE_ENCRCERT))
 478             goto err;
 479         break;
 480
 481     default:
 482         CRMFerr(CRMF_F_OSSL_CRMF_MSG_CREATE_POPO,
 483                 CRMF_R_UNSUPPORTED_METHOD_FOR_CREATING_POPO);
 484         goto err;
 485     }
 486
 487  end:
 488     OSSL_CRMF_POPO_free(crm->popo);
 489     crm->popo = pp;
 490
 491     return 1;
 492  err:
 493     OSSL_CRMF_POPO_free(pp);
 494     return 0;
 495 }
 496
 497 /* returns 0 for equal, -1 for a < b or error on a, 1 for a > b or error on b */
 498 static int X509_PUBKEY_cmp(X509_PUBKEY *a, X509_PUBKEY *b)
 499 {
 500     X509_ALGOR *algA = NULL, *algB = NULL;
 501     int res = 0;
 502
 503     if (a == b)
 504         return 0;
 505     if (a == NULL || !X509_PUBKEY_get0_param(NULL, NULL, NULL, &algA, a)
 506             || algA == NULL)
 507         return -1;
 508     if (b == NULL || !X509_PUBKEY_get0_param(NULL, NULL, NULL, &algB, b)
 509             || algB == NULL)
 510         return 1;
 511     if ((res = X509_ALGOR_cmp(algA, algB)) != 0)
 512         return res;
 513     return EVP_PKEY_cmp(X509_PUBKEY_get0(a), X509_PUBKEY_get0(b));
 514 }
 515
 516 /* verifies the Proof-of-Possession of the request with the given rid in reqs */
 517 int OSSL_CRMF_MSGS_verify_popo(const OSSL_CRMF_MSGS *reqs,
 518                                int rid, int acceptRAVerified)
 519 {
 520     OSSL_CRMF_MSG *req = NULL;
 521     X509_PUBKEY *pubkey = NULL;
 522     OSSL_CRMF_POPOSIGNINGKEY *sig = NULL;
 523
 524     if (reqs == NULL
 525             || (req = sk_OSSL_CRMF_MSG_value(reqs, rid)) == NULL
 526             || req->popo == NULL) {
 527         CRMFerr(CRMF_F_OSSL_CRMF_MSGS_VERIFY_POPO,
 528                 CRMF_R_NULL_ARGUMENT);
 529         return 0;
 530     }
 531
 532     switch (req->popo->type) {
 533     case OSSL_CRMF_POPO_RAVERIFIED:
 534         if (acceptRAVerified)
 535             return 1;
 536         break;
 537     case OSSL_CRMF_POPO_SIGNATURE:
 538         pubkey = req->certReq->certTemplate->publicKey;
 539         sig = req->popo->value.signature;
 540         if (sig->poposkInput != NULL) {
 541             /*
 542              * According to RFC 4211: publicKey contains a copy of
 543              * the public key from the certificate template. This MUST be
 544              * exactly the same value as contained in the certificate template.
 545              */
 546             if (pubkey == NULL
 547                     || sig->poposkInput->publicKey == NULL
 548                     || X509_PUBKEY_cmp(pubkey, sig->poposkInput->publicKey)
 549                     || ASN1_item_verify(
 550                            ASN1_ITEM_rptr(OSSL_CRMF_POPOSIGNINGKEYINPUT),
 551                            sig->algorithmIdentifier, sig->signature,
 552                            sig->poposkInput, X509_PUBKEY_get0(pubkey)) < 1)
 553                 break;
 554         } else {
 555             if (pubkey == NULL
 556                     || req->certReq->certTemplate->subject == NULL
 557                     || ASN1_item_verify(ASN1_ITEM_rptr(OSSL_CRMF_CERTREQUEST),
 558                                     sig->algorithmIdentifier, sig->signature,
 559                                     req->certReq,
 560                                     X509_PUBKEY_get0(pubkey)) < 1)
 561                 break;
 562         }
 563         return 1;
 564     case OSSL_CRMF_POPO_KEYENC:
 565         /*
 566          * TODO: when OSSL_CMP_certrep_new() supports encrypted certs,
 567          * return 1 if the type of req->popo->value.keyEncipherment
 568          * is OSSL_CRMF_POPOPRIVKEY_SUBSEQUENTMESSAGE and
 569          * its value.subsequentMessage == OSSL_CRMF_SUBSEQUENTMESSAGE_ENCRCERT
 570         */
 571     case OSSL_CRMF_POPO_KEYAGREE:
 572     default:
 573         CRMFerr(CRMF_F_OSSL_CRMF_MSGS_VERIFY_POPO,
 574                 CRMF_R_UNSUPPORTED_POPO_METHOD);
 575         return 0;
 576     }
 577     CRMFerr(CRMF_F_OSSL_CRMF_MSGS_VERIFY_POPO,
 578             CRMF_R_UNSUPPORTED_POPO_NOT_ACCEPTED);
 579     return 0;
 580 }
 581
 582 /* retrieves the serialNumber of the given cert template or NULL on error */
 583 ASN1_INTEGER *OSSL_CRMF_CERTTEMPLATE_get0_serialNumber(OSSL_CRMF_CERTTEMPLATE *tmpl)
 584 {
 585     return tmpl != NULL ? tmpl->serialNumber : NULL;
 586 }
 587
 588 /* retrieves the issuer name of the given cert template or NULL on error */
 589 X509_NAME *OSSL_CRMF_CERTTEMPLATE_get0_issuer(OSSL_CRMF_CERTTEMPLATE *tmpl)
 590 {
 591     return tmpl != NULL ? tmpl->issuer : NULL;
 592 }
 593
 594 /* retrieves the issuer name of the given CertId or NULL on error */
 595 X509_NAME *OSSL_CRMF_CERTID_get0_issuer(const OSSL_CRMF_CERTID *cid)
 596 {
 597     return cid != NULL && cid->issuer->type == GEN_DIRNAME ?
 598         cid->issuer->d.directoryName : NULL;
 599 }
 600
 601 /* retrieves the serialNumber of the given CertId or NULL on error */
 602 ASN1_INTEGER *OSSL_CRMF_CERTID_get0_serialNumber(const OSSL_CRMF_CERTID *cid)
 603 {
 604     return cid != NULL ? cid->serialNumber : NULL;
 605 }
 606
 607 /*-
 608  * fill in certificate template.
 609  * Any value argument that is NULL will leave the respective field unchanged.
 610  */
 611 int OSSL_CRMF_CERTTEMPLATE_fill(OSSL_CRMF_CERTTEMPLATE *tmpl,
 612                                 EVP_PKEY *pubkey,
 613                                 const X509_NAME *subject,
 614                                 const X509_NAME *issuer,
 615                                 const ASN1_INTEGER *serial)
 616 {
 617     if (tmpl == NULL) {
 618         CRMFerr(CRMF_F_OSSL_CRMF_CERTTEMPLATE_FILL, CRMF_R_NULL_ARGUMENT);
 619         return 0;
 620     }
 621     if (subject != NULL && !X509_NAME_set(&tmpl->subject, subject))
 622         return 0;
 623     if (issuer != NULL && !X509_NAME_set(&tmpl->issuer, issuer))
 624         return 0;
 625     if (serial != NULL) {
 626         ASN1_INTEGER_free(tmpl->serialNumber);
 627         if ((tmpl->serialNumber = ASN1_INTEGER_dup(serial)) == NULL)
 628             return 0;
 629     }
 630     if (pubkey != NULL && !X509_PUBKEY_set(&tmpl->publicKey, pubkey))
 631         return 0;
 632     return 1;
 633 }
 634
 635
 636 /*-
 637  * Decrypts the certificate in the given encryptedValue using private key pkey.
 638  * This is needed for the indirect PoP method as in RFC 4210 section 5.2.8.2.
 639  *
 640  * returns a pointer to the decrypted certificate
 641  * returns NULL on error or if no certificate available
 642  */
 643 X509 *OSSL_CRMF_ENCRYPTEDVALUE_get1_encCert(OSSL_CRMF_ENCRYPTEDVALUE *ecert,
 644                                             EVP_PKEY *pkey)
 645 {
 646     X509 *cert = NULL; /* decrypted certificate */
 647     EVP_CIPHER_CTX *evp_ctx = NULL; /* context for symmetric encryption */
 648     unsigned char *ek = NULL; /* decrypted symmetric encryption key */
 649     size_t eksize = 0; /* size of decrypted symmetric encryption key */
 650     const EVP_CIPHER *cipher = NULL; /* used cipher */
 651     int cikeysize = 0; /* key size from cipher */
 652     unsigned char *iv = NULL; /* initial vector for symmetric encryption */
 653     unsigned char *outbuf = NULL; /* decryption output buffer */
 654     const unsigned char *p = NULL; /* needed for decoding ASN1 */
 655     int symmAlg = 0; /* NIDs for symmetric algorithm */
 656     int n, outlen = 0;
 657     EVP_PKEY_CTX *pkctx = NULL; /* private key context */
 658
 659     if (ecert == NULL || ecert->symmAlg == NULL || ecert->encSymmKey == NULL
 660             || ecert->encValue == NULL || pkey == NULL) {
 661         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 662                 CRMF_R_NULL_ARGUMENT);
 663         return NULL;
 664     }
 665     if ((symmAlg = OBJ_obj2nid(ecert->symmAlg->algorithm)) == 0) {
 666         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 667                 CRMF_R_UNSUPPORTED_CIPHER);
 668         return NULL;
 669     }
 670     /* select symmetric cipher based on algorithm given in message */
 671     if ((cipher = EVP_get_cipherbynid(symmAlg)) == NULL) {
 672         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 673                 CRMF_R_UNSUPPORTED_CIPHER);
 674         goto end;
 675     }
 676     cikeysize = EVP_CIPHER_key_length(cipher);
 677     /* first the symmetric key needs to be decrypted */
 678     pkctx = EVP_PKEY_CTX_new(pkey, NULL);
 679     if (pkctx != NULL && EVP_PKEY_decrypt_init(pkctx)) {
 680         ASN1_BIT_STRING *encKey = ecert->encSymmKey;
 681         size_t failure;
 682         int retval;
 683
 684         if (EVP_PKEY_decrypt(pkctx, NULL, &eksize,
 685                              encKey->data, encKey->length) <= 0
 686                 || (ek = OPENSSL_malloc(eksize)) == NULL)
 687             goto end;
 688         retval = EVP_PKEY_decrypt(pkctx, ek, &eksize,
 689                                   encKey->data, encKey->length);
 690         ERR_clear_error(); /* error state may have sensitive information */
 691         failure = ~constant_time_is_zero_s(constant_time_msb(retval)
 692                                            | constant_time_is_zero(retval));
 693         failure |= ~constant_time_eq_s(eksize, (size_t)cikeysize);
 694         if (failure) {
 695             CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 696                     CRMF_R_ERROR_DECRYPTING_SYMMETRIC_KEY);
 697             goto end;
 698         }
 699     } else {
 700         goto end;
 701     }
 702     if ((iv = OPENSSL_malloc(EVP_CIPHER_iv_length(cipher))) == NULL)
 703         goto end;
 704     if (ASN1_TYPE_get_octetstring(ecert->symmAlg->parameter, iv,
 705                                    EVP_CIPHER_iv_length(cipher))
 706         != EVP_CIPHER_iv_length(cipher)) {
 707         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 708                 CRMF_R_MALFORMED_IV);
 709         goto end;
 710     }
 711
 712     /*
 713      * d2i_X509 changes the given pointer, so use p for decoding the message and
 714      * keep the original pointer in outbuf so the memory can be freed later
 715      */
 716     if ((p = outbuf = OPENSSL_malloc(ecert->encValue->length +
 717                                      EVP_CIPHER_block_size(cipher))) == NULL
 718             || (evp_ctx = EVP_CIPHER_CTX_new()) == NULL)
 719         goto end;
 720     EVP_CIPHER_CTX_set_padding(evp_ctx, 0);
 721
 722     if (!EVP_DecryptInit(evp_ctx, cipher, ek, iv)
 723             || !EVP_DecryptUpdate(evp_ctx, outbuf, &outlen,
 724                                   ecert->encValue->data,
 725                                   ecert->encValue->length)
 726             || !EVP_DecryptFinal(evp_ctx, outbuf + outlen, &n)) {
 727         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 728                 CRMF_R_ERROR_DECRYPTING_CERTIFICATE);
 729         goto end;
 730     }
 731     outlen += n;
 732
 733     /* convert decrypted certificate from DER to internal ASN.1 structure */
 734     if ((cert = d2i_X509(NULL, &p, outlen)) == NULL) {
 735         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 736                 CRMF_R_ERROR_DECODING_CERTIFICATE);
 737     }
 738  end:
 739     EVP_PKEY_CTX_free(pkctx);
 740     OPENSSL_free(outbuf);
 741     EVP_CIPHER_CTX_free(evp_ctx);
 742     OPENSSL_clear_free(ek, eksize);
 743     OPENSSL_free(iv);
 744     return cert;
 745 }