lib/pkcs11_privkey.c

   1 /*
   2  * GnuTLS PKCS#11 support
   3  * Copyright (C) 2010-2012 Free Software Foundation, Inc.
   4  *
   5  * Authors: Nikos Mavrogiannopoulos, Stef Walter
   6  *
   7  * The GnuTLS is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public License
   9  * as published by the Free Software Foundation; either version 3 of
  10  * the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>
  19  */
  20
  21 #include <gnutls_int.h>
  22 #include <gnutls/pkcs11.h>
  23 #include <stdio.h>
  24 #include <string.h>
  25 #include <gnutls_errors.h>
  26 #include <gnutls_datum.h>
  27 #include <pkcs11_int.h>
  28 #include <gnutls_sig.h>
  29 #include <p11-kit/uri.h>
  30
  31 struct gnutls_pkcs11_privkey_st
  32 {
  33   gnutls_pk_algorithm_t pk_algorithm;
  34   unsigned int flags;
  35   struct p11_kit_uri *info;
  36
  37   struct pkcs11_session_info sinfo;
  38   ck_object_handle_t obj; /* the key in the session */
  39
  40   struct pin_info_st pin;
  41 };
  42
  43 /**
  44  * gnutls_pkcs11_privkey_init:
  45  * @key: The structure to be initialized
  46  *
  47  * This function will initialize an private key structure.
  48  *
  49  * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
  50  *   negative error value.
  51  **/
  52 int
  53 gnutls_pkcs11_privkey_init (gnutls_pkcs11_privkey_t * key)
  54 {
  55   *key = gnutls_calloc (1, sizeof (struct gnutls_pkcs11_privkey_st));
  56   if (*key == NULL)
  57     {
  58       gnutls_assert ();
  59       return GNUTLS_E_MEMORY_ERROR;
  60     }
  61
  62   (*key)->info = p11_kit_uri_new ();
  63   if ((*key)->info == NULL)
  64     {
  65       free (*key);
  66       gnutls_assert ();
  67       return GNUTLS_E_MEMORY_ERROR;
  68     }
  69
  70   return 0;
  71 }
  72
  73 /**
  74  * gnutls_pkcs11_privkey_deinit:
  75  * @key: The structure to be initialized
  76  *
  77  * This function will deinitialize a private key structure.
  78  **/
  79 void
  80 gnutls_pkcs11_privkey_deinit (gnutls_pkcs11_privkey_t key)
  81 {
  82   p11_kit_uri_free (key->info);
  83   if (key->sinfo.init != 0)
  84     pkcs11_close_session (&key->sinfo);
  85   gnutls_free (key);
  86 }
  87
  88 /**
  89  * gnutls_pkcs11_privkey_get_pk_algorithm:
  90  * @key: should contain a #gnutls_pkcs11_privkey_t structure
  91  * @bits: if bits is non null it will hold the size of the parameters' in bits
  92  *
  93  * This function will return the public key algorithm of a private
  94  * key.
  95  *
  96  * Returns: a member of the #gnutls_pk_algorithm_t enumeration on
  97  *   success, or a negative error code on error.
  98  **/
  99 int
 100 gnutls_pkcs11_privkey_get_pk_algorithm (gnutls_pkcs11_privkey_t key,
 101                                         unsigned int *bits)
 102 {
 103   if (bits)
 104     *bits = 0;                  /* FIXME */
 105   return key->pk_algorithm;
 106 }
 107
 108 /**
 109  * gnutls_pkcs11_privkey_get_info:
 110  * @pkey: should contain a #gnutls_pkcs11_privkey_t structure
 111  * @itype: Denotes the type of information requested
 112  * @output: where output will be stored
 113  * @output_size: contains the maximum size of the output and will be overwritten with actual
 114  *
 115  * This function will return information about the PKCS 11 private key such
 116  * as the label, id as well as token information where the key is stored. When
 117  * output is text it returns null terminated string although #output_size contains
 118  * the size of the actual data only.
 119  *
 120  * Returns: %GNUTLS_E_SUCCESS (0) on success or a negative error code on error.
 121  **/
 122 int
 123 gnutls_pkcs11_privkey_get_info (gnutls_pkcs11_privkey_t pkey,
 124                                 gnutls_pkcs11_obj_info_t itype,
 125                                 void *output, size_t * output_size)
 126 {
 127   return pkcs11_get_info (pkey->info, itype, output, output_size);
 128 }
 129
 130
 131 #define FIND_OBJECT(sinfo, pin_info, obj, key) \
 132         do { \
 133                 int retries = 0; \
 134                 int rret; \
 135                 ret = pkcs11_find_object (sinfo, pin_info, &obj, key->info, \
 136                                           SESSION_LOGIN); \
 137                 if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) { \
 138                         if (_gnutls_token_func) \
 139                           { \
 140                             rret = pkcs11_call_token_func (key->info, retries++); \
 141                             if (rret == 0) continue; \
 142                           } \
 143                         return gnutls_assert_val(ret); \
 144                 } else if (ret < 0) { \
 145                         return gnutls_assert_val(ret); \
 146                 } \
 147         } while (0);
 148
 149 /*-
 150  * _gnutls_pkcs11_privkey_sign_hash:
 151  * @key: Holds the key
 152  * @hash: holds the data to be signed (should be output of a hash)
 153  * @signature: will contain the signature allocated with gnutls_malloc()
 154  *
 155  * This function will sign the given data using a signature algorithm
 156  * supported by the private key. It is assumed that the given data
 157  * are the output of a hash function.
 158  *
 159  * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
 160  *   negative error value.
 161  -*/
 162 int
 163 _gnutls_pkcs11_privkey_sign_hash (gnutls_pkcs11_privkey_t key,
 164                                   const gnutls_datum_t * hash,
 165                                   gnutls_datum_t * signature)
 166 {
 167   ck_rv_t rv;
 168   int ret;
 169   struct ck_mechanism mech;
 170   unsigned long siglen;
 171   struct pkcs11_session_info _sinfo;
 172   struct pkcs11_session_info *sinfo;
 173   ck_object_handle_t obj;
 174
 175   if (key->sinfo.init != 0)
 176     {
 177       sinfo = &key->sinfo;
 178       obj = key->obj;
 179     }
 180   else
 181     {
 182       sinfo = &_sinfo;
 183       memset(sinfo, 0, sizeof(*sinfo));
 184       FIND_OBJECT (sinfo, &key->pin, obj, key);
 185     }
 186
 187   mech.mechanism = pk_to_mech(key->pk_algorithm);
 188   mech.parameter = NULL;
 189   mech.parameter_len = 0;
 190
 191   /* Initialize signing operation; using the private key discovered
 192    * earlier. */
 193   rv = pkcs11_sign_init (sinfo->module, sinfo->pks, &mech, obj);
 194   if (rv != CKR_OK)
 195     {
 196       gnutls_assert ();
 197       ret = pkcs11_rv_to_err (rv);
 198       goto cleanup;
 199     }
 200
 201   /* Work out how long the signature must be: */
 202   rv = pkcs11_sign (sinfo->module, sinfo->pks, hash->data, hash->size, NULL, &siglen);
 203   if (rv != CKR_OK)
 204     {
 205       gnutls_assert ();
 206       ret = pkcs11_rv_to_err (rv);
 207       goto cleanup;
 208     }
 209
 210   signature->data = gnutls_malloc (siglen);
 211   signature->size = siglen;
 212
 213   rv = pkcs11_sign (sinfo->module, sinfo->pks, hash->data, hash->size, signature->data, &siglen);
 214   if (rv != CKR_OK)
 215     {
 216       gnutls_free (signature->data);
 217       gnutls_assert ();
 218       ret = pkcs11_rv_to_err (rv);
 219       goto cleanup;
 220     }
 221
 222   signature->size = siglen;
 223
 224   ret = 0;
 225
 226 cleanup:
 227   if (sinfo != &key->sinfo)
 228     pkcs11_close_session (sinfo);
 229
 230   return ret;
 231 }
 232
 233 /**
 234  * gnutls_pkcs11_privkey_import_url:
 235  * @pkey: The structure to store the parsed key
 236  * @url: a PKCS 11 url identifying the key
 237  * @flags: sequence of GNUTLS_PKCS_PRIVKEY_*
 238  *
 239  * This function will "import" a PKCS 11 URL identifying a private
 240  * key to the #gnutls_pkcs11_privkey_t structure. In reality since
 241  * in most cases keys cannot be exported, the private key structure
 242  * is being associated with the available operations on the token.
 243  *
 244  * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
 245  *   negative error value.
 246  **/
 247 int
 248 gnutls_pkcs11_privkey_import_url (gnutls_pkcs11_privkey_t pkey,
 249                                   const char *url, unsigned int flags)
 250 {
 251   int ret;
 252   struct ck_attribute *attr;
 253   ck_object_handle_t obj;
 254   struct ck_attribute a[4];
 255   ck_key_type_t key_type;
 256   struct pkcs11_session_info sinfo;
 257
 258   memset(&sinfo, 0, sizeof(sinfo));
 259
 260   ret = pkcs11_url_to_info (url, &pkey->info);
 261   if (ret < 0)
 262     {
 263       gnutls_assert ();
 264       return ret;
 265     }
 266
 267   pkey->flags = flags;
 268
 269   attr = p11_kit_uri_get_attribute (pkey->info, CKA_CLASS);
 270   if (!attr || attr->value_len != sizeof (ck_object_class_t) ||
 271       *(ck_object_class_t*)attr->value != CKO_PRIVATE_KEY)
 272     {
 273       gnutls_assert ();
 274       return GNUTLS_E_INVALID_REQUEST;
 275     }
 276
 277   attr = p11_kit_uri_get_attribute (pkey->info, CKA_ID);
 278   if (!attr || !attr->value_len)
 279     {
 280       attr = p11_kit_uri_get_attribute (pkey->info, CKA_LABEL);
 281       if (!attr || !attr->value_len)
 282         {
 283           gnutls_assert ();
 284           return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;
 285         }
 286     }
 287
 288   FIND_OBJECT (&sinfo, &pkey->pin, obj, pkey);
 289
 290   a[0].type = CKA_KEY_TYPE;
 291   a[0].value = &key_type;
 292   a[0].value_len = sizeof (key_type);
 293
 294   if (pkcs11_get_attribute_value (sinfo.module, sinfo.pks, obj, a, 1) == CKR_OK)
 295     {
 296       pkey->pk_algorithm = mech_to_pk(key_type);
 297       if (pkey->pk_algorithm == GNUTLS_PK_UNKNOWN)
 298         {
 299           _gnutls_debug_log("Cannot determine PKCS #11 key algorithm\n");
 300           ret = GNUTLS_E_UNKNOWN_ALGORITHM;
 301           goto cleanup;
 302         }
 303     }
 304
 305   ret = 0;
 306
 307   if (pkey->sinfo.init)
 308     pkcs11_close_session (&pkey->sinfo);
 309
 310   if (sinfo.tinfo.max_session_count != 1)
 311     {
 312       /* We do not keep the session open in tokens that can
 313        * only support a single session.
 314        */
 315       memcpy(&pkey->sinfo, &sinfo, sizeof(pkey->sinfo));
 316       pkey->obj = obj;
 317       return ret;
 318     }
 319
 320 cleanup:
 321   pkcs11_close_session (&sinfo);
 322
 323   return ret;
 324 }
 325
 326 /*-
 327  * _gnutls_pkcs11_privkey_decrypt_data:
 328  * @key: Holds the key
 329  * @flags: should be 0 for now
 330  * @ciphertext: holds the data to be signed
 331  * @plaintext: will contain the plaintext, allocated with gnutls_malloc()
 332  *
 333  * This function will decrypt the given data using the public key algorithm
 334  * supported by the private key.
 335  *
 336  * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
 337  *   negative error value.
 338  -*/
 339 int
 340 _gnutls_pkcs11_privkey_decrypt_data (gnutls_pkcs11_privkey_t key,
 341                                     unsigned int flags,
 342                                     const gnutls_datum_t * ciphertext,
 343                                     gnutls_datum_t * plaintext)
 344 {
 345   ck_rv_t rv;
 346   int ret;
 347   struct ck_mechanism mech;
 348   unsigned long siglen;
 349   ck_object_handle_t obj;
 350   struct pkcs11_session_info _sinfo;
 351   struct pkcs11_session_info *sinfo;
 352
 353   if (key->sinfo.init != 0)
 354     {
 355       sinfo = &key->sinfo;
 356       obj = key->obj;
 357     }
 358   else
 359     {
 360       sinfo = &_sinfo;
 361       memset(sinfo, 0, sizeof(*sinfo));
 362       FIND_OBJECT (sinfo, &key->pin, obj, key);
 363     }
 364
 365   if (key->pk_algorithm != GNUTLS_PK_RSA)
 366     return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
 367
 368   mech.mechanism = CKM_RSA_PKCS;
 369   mech.parameter = NULL;
 370   mech.parameter_len = 0;
 371
 372   /* Initialize signing operation; using the private key discovered
 373    * earlier. */
 374   rv = pkcs11_decrypt_init (sinfo->module, sinfo->pks, &mech, obj);
 375   if (rv != CKR_OK)
 376     {
 377       gnutls_assert ();
 378       ret = pkcs11_rv_to_err (rv);
 379       goto cleanup;
 380     }
 381
 382   /* Work out how long the plaintext must be: */
 383   rv = pkcs11_decrypt (sinfo->module, sinfo->pks, ciphertext->data, ciphertext->size,
 384                          NULL, &siglen);
 385   if (rv != CKR_OK)
 386     {
 387       gnutls_assert ();
 388       ret = pkcs11_rv_to_err (rv);
 389       goto cleanup;
 390     }
 391
 392   plaintext->data = gnutls_malloc (siglen);
 393   plaintext->size = siglen;
 394
 395   rv = pkcs11_decrypt (sinfo->module, sinfo->pks, ciphertext->data, ciphertext->size,
 396                          plaintext->data, &siglen);
 397   if (rv != CKR_OK)
 398     {
 399       gnutls_free (plaintext->data);
 400       gnutls_assert ();
 401       ret = pkcs11_rv_to_err (rv);
 402       goto cleanup;
 403     }
 404
 405   plaintext->size = siglen;
 406
 407   ret = 0;
 408
 409 cleanup:
 410   if (key->sinfo.init == 0)
 411     pkcs11_close_session (sinfo);
 412
 413   return ret;
 414 }
 415
 416 /**
 417  * gnutls_pkcs11_privkey_export_url:
 418  * @key: Holds the PKCS 11 key
 419  * @detailed: non zero if a detailed URL is required
 420  * @url: will contain an allocated url
 421  *
 422  * This function will export a URL identifying the given key.
 423  *
 424  * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
 425  *   negative error value.
 426  **/
 427 int
 428 gnutls_pkcs11_privkey_export_url (gnutls_pkcs11_privkey_t key,
 429                                   gnutls_pkcs11_url_type_t detailed,
 430                                   char **url)
 431 {
 432   int ret;
 433
 434   ret = pkcs11_info_to_url (key->info, detailed, url);
 435   if (ret < 0)
 436     {
 437       gnutls_assert ();
 438       return ret;
 439     }
 440
 441   return 0;
 442 }
 443
 444
 445 /**
 446  * gnutls_pkcs11_privkey_generate:
 447  * @url: a token URL
 448  * @pk: the public key algorithm
 449  * @bits: the security bits
 450  * @label: a label
 451  * @flags: should be zero
 452  *
 453  * This function will generate a private key in the specified
 454  * by the @url token. The private key will be generate within
 455  * the token and will not be exportable.
 456  *
 457  * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
 458  *   negative error value.
 459  *
 460  * Since: 3.0
 461  **/
 462 int
 463 gnutls_pkcs11_privkey_generate (const char* url, gnutls_pk_algorithm_t pk,
 464                                 unsigned int bits, const char* label,
 465                                 unsigned int flags)
 466 {
 467   int ret;
 468   const ck_bool_t tval = 1;
 469   const ck_bool_t fval = 0;
 470   struct pkcs11_session_info sinfo;
 471   struct p11_kit_uri *info = NULL;
 472   ck_rv_t rv;
 473   struct ck_attribute a[10], p[10];
 474   ck_object_handle_t pub, priv;
 475   unsigned long _bits = bits;
 476   int a_val, p_val;
 477   struct ck_mechanism mech;
 478
 479   memset(&sinfo, 0, sizeof(sinfo));
 480
 481   ret = pkcs11_url_to_info (url, &info);
 482   if (ret < 0)
 483     {
 484       gnutls_assert ();
 485       return ret;
 486     }
 487
 488   ret =
 489     pkcs11_open_session (&sinfo, NULL, info,
 490                          SESSION_WRITE | pkcs11_obj_flags_to_int (flags));
 491   p11_kit_uri_free (info);
 492
 493   if (ret < 0)
 494     {
 495       gnutls_assert ();
 496       goto cleanup;
 497     }
 498
 499   /* a holds the public key template
 500    * and p the private key */
 501   a_val = p_val = 0;
 502   mech.parameter = NULL;
 503   mech.parameter_len = 0;
 504   mech.mechanism = pk_to_genmech(pk);
 505
 506   switch(pk)
 507     {
 508       case GNUTLS_PK_RSA:
 509         p[p_val].type = CKA_DECRYPT;
 510         p[p_val].value = (void*)&tval;
 511         p[p_val].value_len = sizeof (tval);
 512         p_val++;
 513
 514         p[p_val].type = CKA_SIGN;
 515         p[p_val].value = (void*)&tval;
 516         p[p_val].value_len = sizeof (tval);
 517         p_val++;
 518
 519         a[a_val].type = CKA_ENCRYPT;
 520         a[a_val].value = (void*)&tval;
 521         a[a_val].value_len = sizeof (tval);
 522         a_val++;
 523
 524         a[a_val].type = CKA_VERIFY;
 525         a[a_val].value = (void*)&tval;
 526         a[a_val].value_len = sizeof (tval);
 527         a_val++;
 528
 529         a[a_val].type = CKA_MODULUS_BITS;
 530         a[a_val].value = &_bits;
 531         a[a_val].value_len = sizeof (_bits);
 532         a_val++;
 533         break;
 534       case GNUTLS_PK_DSA:
 535         p[p_val].type = CKA_SIGN;
 536         p[p_val].value = (void*)&tval;
 537         p[p_val].value_len = sizeof (tval);
 538         p_val++;
 539
 540         a[a_val].type = CKA_VERIFY;
 541         a[a_val].value = (void*)&tval;
 542         a[a_val].value_len = sizeof (tval);
 543         a_val++;
 544
 545         a[a_val].type = CKA_MODULUS_BITS;
 546         a[a_val].value = &_bits;
 547         a[a_val].value_len = sizeof (_bits);
 548         a_val++;
 549         break;
 550       case GNUTLS_PK_EC:
 551         p[p_val].type = CKA_SIGN;
 552         p[p_val].value = (void*)&tval;
 553         p[p_val].value_len = sizeof (tval);
 554         p_val++;
 555
 556         a[a_val].type = CKA_VERIFY;
 557         a[a_val].value = (void*)&tval;
 558         a[a_val].value_len = sizeof (tval);
 559         a_val++;
 560
 561         a[a_val].type = CKA_MODULUS_BITS;
 562         a[a_val].value = &_bits;
 563         a[a_val].value_len = sizeof (_bits);
 564         a_val++;
 565         break;
 566       default:
 567         ret = gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
 568         goto cleanup;
 569     }
 570
 571   /* a private key is set always as private unless
 572    * requested otherwise
 573    */
 574   if (flags & GNUTLS_PKCS11_OBJ_FLAG_MARK_NOT_PRIVATE)
 575     {
 576       p[p_val].type = CKA_PRIVATE;
 577       p[p_val].value = (void*)&fval;
 578       p[p_val].value_len = sizeof(fval);
 579       p_val++;
 580     }
 581   else
 582     {
 583       p[p_val].type = CKA_PRIVATE;
 584       p[p_val].value = (void*)&tval;
 585       p[p_val].value_len = sizeof (tval);
 586       p_val++;
 587     }
 588
 589   p[p_val].type = CKA_TOKEN;
 590   p[p_val].value = (void *)&tval;
 591   p[p_val].value_len = sizeof (tval);
 592   p_val++;
 593
 594   if (label)
 595     {
 596       p[p_val].type = CKA_LABEL;
 597       p[p_val].value = (void*)label;
 598       p[p_val].value_len = strlen (label);
 599       p_val++;
 600
 601       a[a_val].type = CKA_LABEL;
 602       a[a_val].value = (void*)label;
 603       a[a_val].value_len = strlen (label);
 604       a_val++;
 605     }
 606
 607   if (flags & GNUTLS_PKCS11_OBJ_FLAG_MARK_SENSITIVE)
 608     {
 609       p[p_val].type = CKA_SENSITIVE;
 610       p[p_val].value = (void*)&tval;
 611       p[p_val].value_len = sizeof (tval);
 612       p_val++;
 613     }
 614   else
 615     {
 616       p[p_val].type = CKA_SENSITIVE;
 617       p[p_val].value = (void*)&fval;
 618       p[p_val].value_len = sizeof (fval);
 619       p_val++;
 620     }
 621
 622   rv = pkcs11_generate_key_pair( sinfo.module, sinfo.pks, &mech, a, a_val, p, p_val, &pub, &priv);
 623   if (rv != CKR_OK)
 624     {
 625       gnutls_assert ();
 626       _gnutls_debug_log ("pkcs11: %s\n", pkcs11_strerror (rv));
 627       ret = pkcs11_rv_to_err (rv);
 628       goto cleanup;
 629     }
 630
 631
 632 cleanup:
 633   if (sinfo.pks != 0)
 634     pkcs11_close_session (&sinfo);
 635
 636   return ret;
 637 }
 638
 639 /**
 640  * gnutls_pkcs11_privkey_set_pin_function:
 641  * @key: The private key
 642  * @fn: the callback
 643  * @userdata: data associated with the callback
 644  *
 645  * This function will set a callback function to be used when
 646  * required to access the object. This function overrides the global
 647  * set using gnutls_pkcs11_set_pin_function().
 648  *
 649  * Since: 3.1.0
 650  *
 651  **/
 652 void gnutls_pkcs11_privkey_set_pin_function (gnutls_pkcs11_privkey_t key,
 653                                              gnutls_pin_callback_t fn, void *userdata)
 654 {
 655   key->pin.cb = fn;
 656   key->pin.data = userdata;
 657 }