crypto/crmf/crmf_lib.c

   1 /*-
   2  * Copyright 2007-2020 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_set0_validity(OSSL_CRMF_MSG *crm,
 245                                 ASN1_TIME *notBefore, ASN1_TIME *notAfter)
 246 {
 247     OSSL_CRMF_OPTIONALVALIDITY *vld;
 248     OSSL_CRMF_CERTTEMPLATE *tmpl = OSSL_CRMF_MSG_get0_tmpl(crm);
 249
 250     if (tmpl == NULL) { /* also crm == NULL implies this */
 251         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET0_VALIDITY, CRMF_R_NULL_ARGUMENT);
 252         return 0;
 253     }
 254
 255     if ((vld = OSSL_CRMF_OPTIONALVALIDITY_new()) == NULL)
 256         return 0;
 257     vld->notBefore = notBefore;
 258     vld->notAfter = notAfter;
 259     tmpl->validity = vld;
 260     return 1;
 261 }
 262
 263
 264 int OSSL_CRMF_MSG_set_certReqId(OSSL_CRMF_MSG *crm, int rid)
 265 {
 266     if (crm == NULL || crm->certReq == NULL || crm->certReq->certReqId == NULL) {
 267         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET_CERTREQID, CRMF_R_NULL_ARGUMENT);
 268         return 0;
 269     }
 270
 271     return ASN1_INTEGER_set(crm->certReq->certReqId, rid);
 272 }
 273
 274 /* get ASN.1 encoded integer, return -1 on error */
 275 static int crmf_asn1_get_int(const ASN1_INTEGER *a)
 276 {
 277     int64_t res;
 278
 279     if (!ASN1_INTEGER_get_int64(&res, a)) {
 280         CRMFerr(0, ASN1_R_INVALID_NUMBER);
 281         return -1;
 282     }
 283     if (res < INT_MIN) {
 284         CRMFerr(0, ASN1_R_TOO_SMALL);
 285         return -1;
 286     }
 287     if (res > INT_MAX) {
 288         CRMFerr(0, ASN1_R_TOO_LARGE);
 289         return -1;
 290     }
 291     return (int)res;
 292 }
 293
 294 int OSSL_CRMF_MSG_get_certReqId(const OSSL_CRMF_MSG *crm)
 295 {
 296     if (crm == NULL || /* not really needed: */ crm->certReq == NULL) {
 297         CRMFerr(CRMF_F_OSSL_CRMF_MSG_GET_CERTREQID, CRMF_R_NULL_ARGUMENT);
 298         return -1;
 299     }
 300     return crmf_asn1_get_int(crm->certReq->certReqId);
 301 }
 302
 303
 304 int OSSL_CRMF_MSG_set0_extensions(OSSL_CRMF_MSG *crm,
 305                                   X509_EXTENSIONS *exts)
 306 {
 307     OSSL_CRMF_CERTTEMPLATE *tmpl = OSSL_CRMF_MSG_get0_tmpl(crm);
 308
 309     if (tmpl == NULL) { /* also crm == NULL implies this */
 310         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET0_EXTENSIONS, CRMF_R_NULL_ARGUMENT);
 311         return 0;
 312     }
 313
 314     if (sk_X509_EXTENSION_num(exts) == 0) {
 315         sk_X509_EXTENSION_free(exts);
 316         exts = NULL; /* do not include empty extensions list */
 317     }
 318
 319     sk_X509_EXTENSION_pop_free(tmpl->extensions, X509_EXTENSION_free);
 320     tmpl->extensions = exts;
 321     return 1;
 322 }
 323
 324
 325 int OSSL_CRMF_MSG_push0_extension(OSSL_CRMF_MSG *crm,
 326                                   X509_EXTENSION *ext)
 327 {
 328     int new = 0;
 329     OSSL_CRMF_CERTTEMPLATE *tmpl = OSSL_CRMF_MSG_get0_tmpl(crm);
 330
 331     if (tmpl == NULL || ext == NULL) { /* also crm == NULL implies this */
 332         CRMFerr(CRMF_F_OSSL_CRMF_MSG_PUSH0_EXTENSION, CRMF_R_NULL_ARGUMENT);
 333         return 0;
 334     }
 335
 336     if (tmpl->extensions == NULL) {
 337         if ((tmpl->extensions = sk_X509_EXTENSION_new_null()) == NULL)
 338             goto err;
 339         new = 1;
 340     }
 341
 342     if (!sk_X509_EXTENSION_push(tmpl->extensions, ext))
 343         goto err;
 344     return 1;
 345  err:
 346     if (new != 0) {
 347         sk_X509_EXTENSION_free(tmpl->extensions);
 348         tmpl->extensions = NULL;
 349     }
 350     return 0;
 351 }
 352
 353 static int create_popo_signature(OSSL_CRMF_POPOSIGNINGKEY *ps,
 354                                  const OSSL_CRMF_CERTREQUEST *cr,
 355                                  EVP_PKEY *pkey, const EVP_MD *digest,
 356                                  OPENSSL_CTX *libctx, const char *propq)
 357 {
 358     if (ps == NULL || cr == NULL || pkey == NULL) {
 359         CRMFerr(0, CRMF_R_NULL_ARGUMENT);
 360         return 0;
 361     }
 362     if (ps->poposkInput != NULL) {
 363         /* TODO: support cases 1+2 defined in RFC 4211, section 4.1 */
 364         CRMFerr(0, CRMF_R_POPOSKINPUT_NOT_SUPPORTED);
 365         return 0;
 366     }
 367
 368     return ASN1_item_sign_ex(ASN1_ITEM_rptr(OSSL_CRMF_CERTREQUEST),
 369                              ps->algorithmIdentifier, NULL, ps->signature, cr,
 370                              NULL, pkey, digest, libctx, propq);
 371 }
 372
 373
 374 int OSSL_CRMF_MSG_create_popo(int meth, OSSL_CRMF_MSG *crm,
 375                               EVP_PKEY *pkey, const EVP_MD *digest,
 376                               OPENSSL_CTX *libctx, const char *propq)
 377 {
 378     OSSL_CRMF_POPO *pp = NULL;
 379     ASN1_INTEGER *tag = NULL;
 380
 381     if (crm == NULL || (meth == OSSL_CRMF_POPO_SIGNATURE && pkey == NULL)) {
 382         CRMFerr(CRMF_F_OSSL_CRMF_MSG_CREATE_POPO, CRMF_R_NULL_ARGUMENT);
 383         return 0;
 384     }
 385
 386     if (meth == OSSL_CRMF_POPO_NONE)
 387         goto end;
 388     if ((pp = OSSL_CRMF_POPO_new()) == NULL)
 389         goto err;
 390     pp->type = meth;
 391
 392     switch (meth) {
 393     case OSSL_CRMF_POPO_RAVERIFIED:
 394         if ((pp->value.raVerified = ASN1_NULL_new()) == NULL)
 395             goto err;
 396         break;
 397
 398     case OSSL_CRMF_POPO_SIGNATURE:
 399         {
 400             OSSL_CRMF_POPOSIGNINGKEY *ps = OSSL_CRMF_POPOSIGNINGKEY_new();
 401
 402             if (ps == NULL)
 403                 goto err;
 404             if (!create_popo_signature(ps, crm->certReq, pkey, digest,
 405                                        libctx, propq)) {
 406                 OSSL_CRMF_POPOSIGNINGKEY_free(ps);
 407                 goto err;
 408             }
 409             pp->value.signature = ps;
 410         }
 411         break;
 412
 413     case OSSL_CRMF_POPO_KEYENC:
 414         if ((pp->value.keyEncipherment = OSSL_CRMF_POPOPRIVKEY_new()) == NULL)
 415             goto err;
 416         tag = ASN1_INTEGER_new();
 417         pp->value.keyEncipherment->type =
 418             OSSL_CRMF_POPOPRIVKEY_SUBSEQUENTMESSAGE;
 419         pp->value.keyEncipherment->value.subsequentMessage = tag;
 420         if (tag == NULL
 421                 || !ASN1_INTEGER_set(tag, OSSL_CRMF_SUBSEQUENTMESSAGE_ENCRCERT))
 422             goto err;
 423         break;
 424
 425     default:
 426         CRMFerr(CRMF_F_OSSL_CRMF_MSG_CREATE_POPO,
 427                 CRMF_R_UNSUPPORTED_METHOD_FOR_CREATING_POPO);
 428         goto err;
 429     }
 430
 431  end:
 432     OSSL_CRMF_POPO_free(crm->popo);
 433     crm->popo = pp;
 434
 435     return 1;
 436  err:
 437     OSSL_CRMF_POPO_free(pp);
 438     return 0;
 439 }
 440
 441 /* verifies the Proof-of-Possession of the request with the given rid in reqs */
 442 int OSSL_CRMF_MSGS_verify_popo(const OSSL_CRMF_MSGS *reqs,
 443                                int rid, int acceptRAVerified,
 444                                OPENSSL_CTX *libctx, const char *propq)
 445 {
 446     OSSL_CRMF_MSG *req = NULL;
 447     X509_PUBKEY *pubkey = NULL;
 448     OSSL_CRMF_POPOSIGNINGKEY *sig = NULL;
 449     const ASN1_ITEM *it;
 450     void *asn;
 451
 452     if (reqs == NULL || (req = sk_OSSL_CRMF_MSG_value(reqs, rid)) == NULL) {
 453         CRMFerr(CRMF_F_OSSL_CRMF_MSGS_VERIFY_POPO, CRMF_R_NULL_ARGUMENT);
 454         return 0;
 455     }
 456
 457     if (req->popo == NULL) {
 458         CRMFerr(0, CRMF_R_POPO_MISSING);
 459         return 0;
 460     }
 461
 462     switch (req->popo->type) {
 463     case OSSL_CRMF_POPO_RAVERIFIED:
 464         if (!acceptRAVerified) {
 465             CRMFerr(0, CRMF_R_POPO_RAVERIFIED_NOT_ACCEPTED);
 466             return 0;
 467         }
 468         break;
 469     case OSSL_CRMF_POPO_SIGNATURE:
 470         pubkey = req->certReq->certTemplate->publicKey;
 471         if (pubkey == NULL) {
 472             CRMFerr(0, CRMF_R_POPO_MISSING_PUBLIC_KEY);
 473             return 0;
 474         }
 475         sig = req->popo->value.signature;
 476         if (sig->poposkInput != NULL) {
 477             /*
 478              * According to RFC 4211: publicKey contains a copy of
 479              * the public key from the certificate template. This MUST be
 480              * exactly the same value as contained in the certificate template.
 481              */
 482             if (sig->poposkInput->publicKey == NULL) {
 483                 CRMFerr(0, CRMF_R_POPO_MISSING_PUBLIC_KEY);
 484                 return 0;
 485             }
 486             if (X509_PUBKEY_eq(pubkey, sig->poposkInput->publicKey) != 1) {
 487                 CRMFerr(0, CRMF_R_POPO_INCONSISTENT_PUBLIC_KEY);
 488                 return 0;
 489             }
 490             /*
 491              * TODO check the contents of the authInfo sub-field,
 492              * see RFC 4211 https://tools.ietf.org/html/rfc4211#section-4.1
 493              */
 494             it = ASN1_ITEM_rptr(OSSL_CRMF_POPOSIGNINGKEYINPUT);
 495             asn = sig->poposkInput;
 496         } else {
 497             if (req->certReq->certTemplate->subject == NULL) {
 498                 CRMFerr(0, CRMF_R_POPO_MISSING_SUBJECT);
 499                 return 0;
 500             }
 501             it = ASN1_ITEM_rptr(OSSL_CRMF_CERTREQUEST);
 502             asn = req->certReq;
 503         }
 504         if (ASN1_item_verify_ex(it, sig->algorithmIdentifier, sig->signature,
 505                                 asn, NULL, X509_PUBKEY_get0(pubkey), libctx,
 506                                 propq) < 1)
 507             return 0;
 508         break;
 509     case OSSL_CRMF_POPO_KEYENC:
 510         /*
 511          * TODO: when OSSL_CMP_certrep_new() supports encrypted certs,
 512          * return 1 if the type of req->popo->value.keyEncipherment
 513          * is OSSL_CRMF_POPOPRIVKEY_SUBSEQUENTMESSAGE and
 514          * its value.subsequentMessage == OSSL_CRMF_SUBSEQUENTMESSAGE_ENCRCERT
 515          */
 516     case OSSL_CRMF_POPO_KEYAGREE:
 517     default:
 518         CRMFerr(CRMF_F_OSSL_CRMF_MSGS_VERIFY_POPO,
 519                 CRMF_R_UNSUPPORTED_POPO_METHOD);
 520         return 0;
 521     }
 522     return 1;
 523 }
 524
 525 /* retrieves the serialNumber of the given cert template or NULL on error */
 526 ASN1_INTEGER
 527 *OSSL_CRMF_CERTTEMPLATE_get0_serialNumber(const OSSL_CRMF_CERTTEMPLATE *tmpl)
 528 {
 529     return tmpl != NULL ? tmpl->serialNumber : NULL;
 530 }
 531
 532 /* retrieves the issuer name of the given cert template or NULL on error */
 533 const X509_NAME
 534     *OSSL_CRMF_CERTTEMPLATE_get0_issuer(const OSSL_CRMF_CERTTEMPLATE *tmpl)
 535 {
 536     return tmpl != NULL ? tmpl->issuer : NULL;
 537 }
 538
 539 /* retrieves the issuer name of the given CertId or NULL on error */
 540 const X509_NAME *OSSL_CRMF_CERTID_get0_issuer(const OSSL_CRMF_CERTID *cid)
 541 {
 542     return cid != NULL && cid->issuer->type == GEN_DIRNAME ?
 543         cid->issuer->d.directoryName : NULL;
 544 }
 545
 546 /* retrieves the serialNumber of the given CertId or NULL on error */
 547 ASN1_INTEGER *OSSL_CRMF_CERTID_get0_serialNumber(const OSSL_CRMF_CERTID *cid)
 548 {
 549     return cid != NULL ? cid->serialNumber : NULL;
 550 }
 551
 552 /*-
 553  * fill in certificate template.
 554  * Any value argument that is NULL will leave the respective field unchanged.
 555  */
 556 int OSSL_CRMF_CERTTEMPLATE_fill(OSSL_CRMF_CERTTEMPLATE *tmpl,
 557                                 EVP_PKEY *pubkey,
 558                                 const X509_NAME *subject,
 559                                 const X509_NAME *issuer,
 560                                 const ASN1_INTEGER *serial)
 561 {
 562     if (tmpl == NULL) {
 563         CRMFerr(CRMF_F_OSSL_CRMF_CERTTEMPLATE_FILL, CRMF_R_NULL_ARGUMENT);
 564         return 0;
 565     }
 566     if (subject != NULL && !X509_NAME_set((X509_NAME **)&tmpl->subject, subject))
 567         return 0;
 568     if (issuer != NULL && !X509_NAME_set((X509_NAME **)&tmpl->issuer, issuer))
 569         return 0;
 570     if (serial != NULL) {
 571         ASN1_INTEGER_free(tmpl->serialNumber);
 572         if ((tmpl->serialNumber = ASN1_INTEGER_dup(serial)) == NULL)
 573             return 0;
 574     }
 575     if (pubkey != NULL && !X509_PUBKEY_set(&tmpl->publicKey, pubkey))
 576         return 0;
 577     return 1;
 578 }
 579
 580
 581 /*-
 582  * Decrypts the certificate in the given encryptedValue using private key pkey.
 583  * This is needed for the indirect PoP method as in RFC 4210 section 5.2.8.2.
 584  *
 585  * returns a pointer to the decrypted certificate
 586  * returns NULL on error or if no certificate available
 587  */
 588 X509
 589 *OSSL_CRMF_ENCRYPTEDVALUE_get1_encCert(const OSSL_CRMF_ENCRYPTEDVALUE *ecert,
 590                                        OPENSSL_CTX *libctx, const char *propq,
 591                                        EVP_PKEY *pkey)
 592 {
 593     X509 *cert = NULL; /* decrypted certificate */
 594     EVP_CIPHER_CTX *evp_ctx = NULL; /* context for symmetric encryption */
 595     unsigned char *ek = NULL; /* decrypted symmetric encryption key */
 596     size_t eksize = 0; /* size of decrypted symmetric encryption key */
 597     const EVP_CIPHER *cipher = NULL; /* used cipher */
 598     int cikeysize = 0; /* key size from cipher */
 599     unsigned char *iv = NULL; /* initial vector for symmetric encryption */
 600     unsigned char *outbuf = NULL; /* decryption output buffer */
 601     const unsigned char *p = NULL; /* needed for decoding ASN1 */
 602     int symmAlg = 0; /* NIDs for symmetric algorithm */
 603     int n, outlen = 0;
 604     EVP_PKEY_CTX *pkctx = NULL; /* private key context */
 605
 606     if (ecert == NULL || ecert->symmAlg == NULL || ecert->encSymmKey == NULL
 607             || ecert->encValue == NULL || pkey == NULL) {
 608         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 609                 CRMF_R_NULL_ARGUMENT);
 610         return NULL;
 611     }
 612     if ((symmAlg = OBJ_obj2nid(ecert->symmAlg->algorithm)) == 0) {
 613         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 614                 CRMF_R_UNSUPPORTED_CIPHER);
 615         return NULL;
 616     }
 617     /* select symmetric cipher based on algorithm given in message */
 618     if ((cipher = EVP_get_cipherbynid(symmAlg)) == NULL) {
 619         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 620                 CRMF_R_UNSUPPORTED_CIPHER);
 621         goto end;
 622     }
 623     cikeysize = EVP_CIPHER_key_length(cipher);
 624     /* first the symmetric key needs to be decrypted */
 625     pkctx = EVP_PKEY_CTX_new_from_pkey(libctx, pkey, propq);
 626     if (pkctx != NULL && EVP_PKEY_decrypt_init(pkctx)) {
 627         ASN1_BIT_STRING *encKey = ecert->encSymmKey;
 628         size_t failure;
 629         int retval;
 630
 631         if (EVP_PKEY_decrypt(pkctx, NULL, &eksize,
 632                              encKey->data, encKey->length) <= 0
 633                 || (ek = OPENSSL_malloc(eksize)) == NULL)
 634             goto end;
 635         retval = EVP_PKEY_decrypt(pkctx, ek, &eksize,
 636                                   encKey->data, encKey->length);
 637         ERR_clear_error(); /* error state may have sensitive information */
 638         failure = ~constant_time_is_zero_s(constant_time_msb(retval)
 639                                            | constant_time_is_zero(retval));
 640         failure |= ~constant_time_eq_s(eksize, (size_t)cikeysize);
 641         if (failure) {
 642             CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 643                     CRMF_R_ERROR_DECRYPTING_SYMMETRIC_KEY);
 644             goto end;
 645         }
 646     } else {
 647         goto end;
 648     }
 649     if ((iv = OPENSSL_malloc(EVP_CIPHER_iv_length(cipher))) == NULL)
 650         goto end;
 651     if (ASN1_TYPE_get_octetstring(ecert->symmAlg->parameter, iv,
 652                                   EVP_CIPHER_iv_length(cipher))
 653         != EVP_CIPHER_iv_length(cipher)) {
 654         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 655                 CRMF_R_MALFORMED_IV);
 656         goto end;
 657     }
 658
 659     /*
 660      * d2i_X509 changes the given pointer, so use p for decoding the message and
 661      * keep the original pointer in outbuf so the memory can be freed later
 662      */
 663     if ((p = outbuf = OPENSSL_malloc(ecert->encValue->length +
 664                                      EVP_CIPHER_block_size(cipher))) == NULL
 665             || (evp_ctx = EVP_CIPHER_CTX_new()) == NULL)
 666         goto end;
 667     EVP_CIPHER_CTX_set_padding(evp_ctx, 0);
 668
 669     if (!EVP_DecryptInit(evp_ctx, cipher, ek, iv)
 670             || !EVP_DecryptUpdate(evp_ctx, outbuf, &outlen,
 671                                   ecert->encValue->data,
 672                                   ecert->encValue->length)
 673             || !EVP_DecryptFinal(evp_ctx, outbuf + outlen, &n)) {
 674         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 675                 CRMF_R_ERROR_DECRYPTING_CERTIFICATE);
 676         goto end;
 677     }
 678     outlen += n;
 679
 680     /* convert decrypted certificate from DER to internal ASN.1 structure */
 681     if ((cert = X509_new_ex(libctx, propq)) == NULL)
 682         goto end;
 683     if (d2i_X509(&cert, &p, outlen) == NULL)
 684         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 685                 CRMF_R_ERROR_DECODING_CERTIFICATE);
 686  end:
 687     EVP_PKEY_CTX_free(pkctx);
 688     OPENSSL_free(outbuf);
 689     EVP_CIPHER_CTX_free(evp_ctx);
 690     OPENSSL_clear_free(ek, eksize);
 691     OPENSSL_free(iv);
 692     return cert;
 693 }