scd/iso7816.c

   1 /* iso7816.c - ISO 7816 commands
   2  * Copyright (C) 2003, 2004, 2008, 2009 Free Software Foundation, Inc.
   3  *
   4  * This file is part of GnuPG.
   5  *
   6  * GnuPG is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * GnuPG is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  * $Id$
  20  */
  21
  22 #include <config.h>
  23 #include <errno.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #if defined(GNUPG_SCD_MAIN_HEADER)
  29 #include GNUPG_SCD_MAIN_HEADER
  30 #elif GNUPG_MAJOR_VERSION == 1
  31 /* This is used with GnuPG version < 1.9.  The code has been source
  32    copied from the current GnuPG >= 1.9  and is maintained over
  33    there. */
  34 #include "options.h"
  35 #include "errors.h"
  36 #include "memory.h"
  37 #include "util.h"
  38 #include "i18n.h"
  39 #else /* GNUPG_MAJOR_VERSION != 1 */
  40 #include "scdaemon.h"
  41 #endif /* GNUPG_MAJOR_VERSION != 1 */
  42
  43 #include "iso7816.h"
  44 #include "apdu.h"
  45
  46
  47 #define CMD_SELECT_FILE 0xA4
  48 #define CMD_VERIFY                ISO7816_VERIFY
  49 #define CMD_CHANGE_REFERENCE_DATA ISO7816_CHANGE_REFERENCE_DATA
  50 #define CMD_RESET_RETRY_COUNTER   ISO7816_RESET_RETRY_COUNTER
  51 #define CMD_GET_DATA    0xCA
  52 #define CMD_PUT_DATA    0xDA
  53 #define CMD_MSE         0x22
  54 #define CMD_PSO         0x2A
  55 #define CMD_INTERNAL_AUTHENTICATE 0x88
  56 #define CMD_GENERATE_KEYPAIR      0x47
  57 #define CMD_GET_CHALLENGE         0x84
  58 #define CMD_READ_BINARY 0xB0
  59 #define CMD_READ_RECORD 0xB2
  60
  61 static gpg_error_t
  62 map_sw (int sw)
  63 {
  64   gpg_err_code_t ec;
  65
  66   switch (sw)
  67     {
  68     case SW_EEPROM_FAILURE: ec = GPG_ERR_HARDWARE; break;
  69     case SW_TERM_STATE:     ec = GPG_ERR_CARD; break;
  70     case SW_WRONG_LENGTH:   ec = GPG_ERR_INV_VALUE; break;
  71     case SW_SM_NOT_SUP:     ec = GPG_ERR_NOT_SUPPORTED; break;
  72     case SW_CC_NOT_SUP:     ec = GPG_ERR_NOT_SUPPORTED; break;
  73     case SW_CHV_WRONG:      ec = GPG_ERR_BAD_PIN; break;
  74     case SW_CHV_BLOCKED:    ec = GPG_ERR_PIN_BLOCKED; break;
  75     case SW_USE_CONDITIONS: ec = GPG_ERR_USE_CONDITIONS; break;
  76     case SW_NOT_SUPPORTED:  ec = GPG_ERR_NOT_SUPPORTED; break;
  77     case SW_BAD_PARAMETER:  ec = GPG_ERR_INV_VALUE; break;
  78     case SW_FILE_NOT_FOUND: ec = GPG_ERR_ENOENT; break;
  79     case SW_RECORD_NOT_FOUND:ec= GPG_ERR_NOT_FOUND; break;
  80     case SW_REF_NOT_FOUND:  ec = GPG_ERR_NO_OBJ; break;
  81     case SW_BAD_P0_P1:      ec = GPG_ERR_INV_VALUE; break;
  82     case SW_EXACT_LENGTH:   ec = GPG_ERR_INV_VALUE; break;
  83     case SW_INS_NOT_SUP:    ec = GPG_ERR_CARD; break;
  84     case SW_CLA_NOT_SUP:    ec = GPG_ERR_CARD; break;
  85     case SW_SUCCESS:        ec = 0; break;
  86
  87     case SW_HOST_OUT_OF_CORE: ec = GPG_ERR_ENOMEM; break;
  88     case SW_HOST_INV_VALUE:   ec = GPG_ERR_INV_VALUE; break;
  89     case SW_HOST_INCOMPLETE_CARD_RESPONSE: ec = GPG_ERR_CARD; break;
  90     case SW_HOST_NOT_SUPPORTED: ec = GPG_ERR_NOT_SUPPORTED; break;
  91     case SW_HOST_LOCKING_FAILED: ec = GPG_ERR_BUG; break;
  92     case SW_HOST_BUSY:           ec = GPG_ERR_EBUSY; break;
  93     case SW_HOST_NO_CARD:        ec = GPG_ERR_CARD_NOT_PRESENT; break;
  94     case SW_HOST_CARD_INACTIVE:  ec = GPG_ERR_CARD_RESET; break;
  95     case SW_HOST_CARD_IO_ERROR:  ec = GPG_ERR_EIO; break;
  96     case SW_HOST_GENERAL_ERROR:  ec = GPG_ERR_GENERAL; break;
  97     case SW_HOST_NO_READER:      ec = GPG_ERR_ENODEV; break;
  98     case SW_HOST_ABORTED:        ec = GPG_ERR_CANCELED; break;
  99     case SW_HOST_NO_KEYPAD:      ec = GPG_ERR_NOT_SUPPORTED; break;
 100
 101     default:
 102       if ((sw & 0x010000))
 103         ec = GPG_ERR_GENERAL; /* Should not happen. */
 104       else if ((sw & 0xff00) == SW_MORE_DATA)
 105         ec = 0; /* This should actually never been seen here. */
 106       else
 107         ec = GPG_ERR_CARD;
 108     }
 109   return gpg_error (ec);
 110 }
 111
 112 /* Map a status word from the APDU layer to a gpg-error code.  */
 113 gpg_error_t
 114 iso7816_map_sw (int sw)
 115 {
 116   /* All APDU functions should return 0x9000 on success but for
 117      historical reasons of the implementation some return 0 to
 118      indicate success.  We allow for that here. */
 119   return sw? map_sw (sw) : 0;
 120 }
 121
 122
 123 /* This function is specialized version of the SELECT FILE command.
 124    SLOT is the card and reader as created for example by
 125    apdu_open_reader (), AID is a buffer of size AIDLEN holding the
 126    requested application ID.  The function can't be used to enumerate
 127    AIDs and won't return the AID on success.  The return value is 0
 128    for okay or a GPG error code.  Note that ISO error codes are
 129    internally mapped.  Bit 0 of FLAGS should be set if the card does
 130    not understand P2=0xC0. */
 131 gpg_error_t
 132 iso7816_select_application (int slot, const char *aid, size_t aidlen,
 133                             unsigned int flags)
 134 {
 135   int sw;
 136   sw = apdu_send_simple (slot, 0, 0x00, CMD_SELECT_FILE, 4,
 137                          (flags&1)? 0 :0x0c, aidlen, aid);
 138   return map_sw (sw);
 139 }
 140
 141
 142 gpg_error_t
 143 iso7816_select_file (int slot, int tag, int is_dir,
 144                      unsigned char **result, size_t *resultlen)
 145 {
 146   int sw, p0, p1;
 147   unsigned char tagbuf[2];
 148
 149   tagbuf[0] = (tag >> 8) & 0xff;
 150   tagbuf[1] = tag & 0xff;
 151
 152   if (result || resultlen)
 153     {
 154       *result = NULL;
 155       *resultlen = 0;
 156       return gpg_error (GPG_ERR_NOT_IMPLEMENTED);
 157     }
 158   else
 159     {
 160       p0 = (tag == 0x3F00)? 0: is_dir? 1:2;
 161       p1 = 0x0c; /* No FC return. */
 162       sw = apdu_send_simple (slot, 0, 0x00, CMD_SELECT_FILE,
 163                              p0, p1, 2, (char*)tagbuf );
 164       return map_sw (sw);
 165     }
 166
 167   return 0;
 168 }
 169
 170
 171 /* Do a select file command with a direct path. */
 172 gpg_error_t
 173 iso7816_select_path (int slot, const unsigned short *path, size_t pathlen,
 174                      unsigned char **result, size_t *resultlen)
 175 {
 176   int sw, p0, p1;
 177   unsigned char buffer[100];
 178   int buflen;
 179
 180   if (result || resultlen)
 181     {
 182       *result = NULL;
 183       *resultlen = 0;
 184       return gpg_error (GPG_ERR_NOT_IMPLEMENTED);
 185     }
 186
 187   if (pathlen/2 >= sizeof buffer)
 188     return gpg_error (GPG_ERR_TOO_LARGE);
 189
 190   for (buflen = 0; pathlen; pathlen--, path++)
 191     {
 192       buffer[buflen++] = (*path >> 8);
 193       buffer[buflen++] = *path;
 194     }
 195
 196   p0 = 0x08;
 197   p1 = 0x0c; /* No FC return. */
 198   sw = apdu_send_simple (slot, 0, 0x00, CMD_SELECT_FILE,
 199                          p0, p1, buflen, (char*)buffer );
 200   return map_sw (sw);
 201 }
 202
 203
 204 /* This is a private command currently only working for TCOS cards. */
 205 gpg_error_t
 206 iso7816_list_directory (int slot, int list_dirs,
 207                         unsigned char **result, size_t *resultlen)
 208 {
 209   int sw;
 210
 211   if (!result || !resultlen)
 212     return gpg_error (GPG_ERR_INV_VALUE);
 213   *result = NULL;
 214   *resultlen = 0;
 215
 216   sw = apdu_send (slot, 0, 0x80, 0xAA, list_dirs? 1:2, 0, -1, NULL,
 217                   result, resultlen);
 218   if (sw != SW_SUCCESS)
 219     {
 220       /* Make sure that pending buffers are released. */
 221       xfree (*result);
 222       *result = NULL;
 223       *resultlen = 0;
 224     }
 225   return map_sw (sw);
 226 }
 227
 228
 229 /* This funcion sends an already formatted APDU to the card.  With
 230    HANDLE_MORE set to true a MORE DATA status will be handled
 231    internally.  The return value is a gpg error code (i.e. a mapped
 232    status word).  This is basically the same as apdu_send_direct but
 233    it maps the status word and does not return it in the result
 234    buffer.  */
 235 gpg_error_t
 236 iso7816_apdu_direct (int slot, const void *apdudata, size_t apdudatalen,
 237                      int handle_more,
 238                      unsigned char **result, size_t *resultlen)
 239 {
 240   int sw;
 241
 242   if (!result || !resultlen)
 243     return gpg_error (GPG_ERR_INV_VALUE);
 244   *result = NULL;
 245   *resultlen = 0;
 246
 247   sw = apdu_send_direct (slot, 0, apdudata, apdudatalen, handle_more,
 248                          result, resultlen);
 249   if (!sw)
 250     {
 251       if (*resultlen < 2)
 252         sw = SW_HOST_GENERAL_ERROR;
 253       else
 254         {
 255           sw = ((*result)[*resultlen-2] << 8) | (*result)[*resultlen-1];
 256           (*resultlen)--;
 257           (*resultlen)--;
 258         }
 259     }
 260   if (sw != SW_SUCCESS)
 261     {
 262       /* Make sure that pending buffers are released. */
 263       xfree (*result);
 264       *result = NULL;
 265       *resultlen = 0;
 266     }
 267   return map_sw (sw);
 268 }
 269
 270
 271 /* Check whether the reader supports the ISO command code COMMAND on
 272    the keypad.  Returns 0 on success.  */
 273 gpg_error_t
 274 iso7816_check_keypad (int slot, int command, iso7816_pininfo_t *pininfo)
 275 {
 276   int sw;
 277
 278   sw = apdu_check_keypad (slot, command,
 279                           pininfo->mode, pininfo->minlen, pininfo->maxlen,
 280                           pininfo->padlen);
 281   return iso7816_map_sw (sw);
 282 }
 283
 284
 285 /* Perform a VERIFY command on SLOT using the card holder verification
 286    vector CHVNO with a CHV of lenght CHVLEN.  With PININFO non-NULL
 287    the keypad of the reader will be used.  Returns 0 on success. */
 288 gpg_error_t
 289 iso7816_verify_kp (int slot, int chvno, const char *chv, size_t chvlen,
 290                    iso7816_pininfo_t *pininfo)
 291 {
 292   int sw;
 293
 294   if (pininfo && pininfo->mode)
 295     sw = apdu_send_simple_kp (slot, 0x00, CMD_VERIFY, 0, chvno, chvlen, chv,
 296                               pininfo->mode,
 297                               pininfo->minlen,
 298                               pininfo->maxlen,
 299                               pininfo->padlen);
 300   else
 301     sw = apdu_send_simple (slot, 0, 0x00, CMD_VERIFY, 0, chvno, chvlen, chv);
 302   return map_sw (sw);
 303 }
 304
 305 /* Perform a VERIFY command on SLOT using the card holder verification
 306    vector CHVNO with a CHV of lenght CHVLEN.  Returns 0 on success. */
 307 gpg_error_t
 308 iso7816_verify (int slot, int chvno, const char *chv, size_t chvlen)
 309 {
 310   return iso7816_verify_kp (slot, chvno, chv, chvlen, NULL);
 311 }
 312
 313 /* Perform a CHANGE_REFERENCE_DATA command on SLOT for the card holder
 314    verification vector CHVNO.  If the OLDCHV is NULL (and OLDCHVLEN
 315    0), a "change reference data" is done, otherwise an "exchange
 316    reference data".  The new reference data is expected in NEWCHV of
 317    length NEWCHVLEN.  With PININFO non-NULL the keypad of the reader
 318    will be used.  */
 319 gpg_error_t
 320 iso7816_change_reference_data_kp (int slot, int chvno,
 321                                   const char *oldchv, size_t oldchvlen,
 322                                   const char *newchv, size_t newchvlen,
 323                                   iso7816_pininfo_t *pininfo)
 324 {
 325   int sw;
 326   char *buf;
 327
 328   if ((!oldchv && oldchvlen)
 329       || (oldchv && !oldchvlen)
 330       || !newchv || !newchvlen )
 331     return gpg_error (GPG_ERR_INV_VALUE);
 332
 333   buf = xtrymalloc (oldchvlen + newchvlen);
 334   if (!buf)
 335     return gpg_error (gpg_err_code_from_errno (errno));
 336   if (oldchvlen)
 337     memcpy (buf, oldchv, oldchvlen);
 338   memcpy (buf+oldchvlen, newchv, newchvlen);
 339
 340   if (pininfo && pininfo->mode)
 341     sw = apdu_send_simple_kp (slot, 0x00, CMD_CHANGE_REFERENCE_DATA,
 342                            oldchvlen? 0 : 1, chvno, oldchvlen+newchvlen, buf,
 343                            pininfo->mode,
 344                            pininfo->minlen,
 345                            pininfo->maxlen,
 346                            pininfo->padlen);
 347   else
 348     sw = apdu_send_simple (slot, 0, 0x00, CMD_CHANGE_REFERENCE_DATA,
 349                            oldchvlen? 0 : 1, chvno, oldchvlen+newchvlen, buf);
 350   xfree (buf);
 351   return map_sw (sw);
 352
 353 }
 354
 355 /* Perform a CHANGE_REFERENCE_DATA command on SLOT for the card holder
 356    verification vector CHVNO.  If the OLDCHV is NULL (and OLDCHVLEN
 357    0), a "change reference data" is done, otherwise an "exchange
 358    reference data".  The new reference data is expected in NEWCHV of
 359    length NEWCHVLEN.  */
 360 gpg_error_t
 361 iso7816_change_reference_data (int slot, int chvno,
 362                                const char *oldchv, size_t oldchvlen,
 363                                const char *newchv, size_t newchvlen)
 364 {
 365   return iso7816_change_reference_data_kp (slot, chvno, oldchv, oldchvlen,
 366                                            newchv, newchvlen, NULL);
 367 }
 368
 369
 370 gpg_error_t
 371 iso7816_reset_retry_counter_kp (int slot, int chvno,
 372                                 const char *newchv, size_t newchvlen,
 373                                 iso7816_pininfo_t *pininfo)
 374 {
 375   int sw;
 376
 377   if (!newchv || !newchvlen )
 378     return gpg_error (GPG_ERR_INV_VALUE);
 379
 380   /* FIXME:  The keypad mode has not yet been tested.  */
 381   if (pininfo && pininfo->mode)
 382     sw = apdu_send_simple_kp (slot, 0x00, CMD_RESET_RETRY_COUNTER,
 383                            2, chvno, newchvlen, newchv,
 384                            pininfo->mode,
 385                            pininfo->minlen,
 386                            pininfo->maxlen,
 387                            pininfo->padlen);
 388   else
 389     sw = apdu_send_simple (slot, 0, 0x00, CMD_RESET_RETRY_COUNTER,
 390                            2, chvno, newchvlen, newchv);
 391   return map_sw (sw);
 392 }
 393
 394
 395 gpg_error_t
 396 iso7816_reset_retry_counter_with_rc (int slot, int chvno,
 397                                      const char *data, size_t datalen)
 398 {
 399   int sw;
 400
 401   if (!data || !datalen )
 402     return gpg_error (GPG_ERR_INV_VALUE);
 403
 404   sw = apdu_send_simple (slot, 0, 0x00, CMD_RESET_RETRY_COUNTER,
 405                          0, chvno, datalen, data);
 406   return map_sw (sw);
 407 }
 408
 409
 410 gpg_error_t
 411 iso7816_reset_retry_counter (int slot, int chvno,
 412                              const char *newchv, size_t newchvlen)
 413 {
 414   return iso7816_reset_retry_counter_kp (slot, chvno, newchv, newchvlen, NULL);
 415 }
 416
 417
 418
 419 /* Perform a GET DATA command requesting TAG and storing the result in
 420    a newly allocated buffer at the address passed by RESULT.  Return
 421    the length of this data at the address of RESULTLEN. */
 422 gpg_error_t
 423 iso7816_get_data (int slot, int tag,
 424                   unsigned char **result, size_t *resultlen)
 425 {
 426   int sw;
 427
 428   if (!result || !resultlen)
 429     return gpg_error (GPG_ERR_INV_VALUE);
 430   *result = NULL;
 431   *resultlen = 0;
 432
 433   sw = apdu_send (slot, 0, 0x00, CMD_GET_DATA,
 434                   ((tag >> 8) & 0xff), (tag & 0xff), -1, NULL,
 435                   result, resultlen);
 436   if (sw != SW_SUCCESS)
 437     {
 438       /* Make sure that pending buffers are released. */
 439       xfree (*result);
 440       *result = NULL;
 441       *resultlen = 0;
 442       return map_sw (sw);
 443     }
 444
 445   return 0;
 446 }
 447
 448
 449 /* Perform a PUT DATA command on card in SLOT.  Write DATA of length
 450    DATALEN to TAG.  EXTENDED_MODE controls whether extended length
 451    headers or command chaining is used instead of single length
 452    bytes. */
 453 gpg_error_t
 454 iso7816_put_data (int slot, int extended_mode, int tag,
 455                   const unsigned char *data, size_t datalen)
 456 {
 457   int sw;
 458
 459   sw = apdu_send_simple (slot, extended_mode, 0x00, CMD_PUT_DATA,
 460                          ((tag >> 8) & 0xff), (tag & 0xff),
 461                          datalen, (const char*)data);
 462   return map_sw (sw);
 463 }
 464
 465 /* Same as iso7816_put_data but uses an odd instruction byte.  */
 466 gpg_error_t
 467 iso7816_put_data_odd (int slot, int extended_mode, int tag,
 468                       const unsigned char *data, size_t datalen)
 469 {
 470   int sw;
 471
 472   sw = apdu_send_simple (slot, extended_mode, 0x00, CMD_PUT_DATA+1,
 473                          ((tag >> 8) & 0xff), (tag & 0xff),
 474                          datalen, (const char*)data);
 475   return map_sw (sw);
 476 }
 477
 478 /* Manage Security Environment.  This is a weird operation and there
 479    is no easy abstraction for it.  Furthermore, some card seem to have
 480    a different interpreation of 7816-8 and thus we resort to let the
 481    caller decide what to do. */
 482 gpg_error_t
 483 iso7816_manage_security_env (int slot, int p1, int p2,
 484                              const unsigned char *data, size_t datalen)
 485 {
 486   int sw;
 487
 488   if (p1 < 0 || p1 > 255 || p2 < 0 || p2 > 255 )
 489     return gpg_error (GPG_ERR_INV_VALUE);
 490
 491   sw = apdu_send_simple (slot, 0, 0x00, CMD_MSE, p1, p2,
 492                          data? datalen : -1, (const char*)data);
 493   return map_sw (sw);
 494 }
 495
 496
 497 /* Perform the security operation COMPUTE DIGITAL SIGANTURE.  On
 498    success 0 is returned and the data is availavle in a newly
 499    allocated buffer stored at RESULT with its length stored at
 500    RESULTLEN. */
 501 gpg_error_t
 502 iso7816_compute_ds (int slot, const unsigned char *data, size_t datalen,
 503                     unsigned char **result, size_t *resultlen)
 504 {
 505   int sw;
 506
 507   if (!data || !datalen || !result || !resultlen)
 508     return gpg_error (GPG_ERR_INV_VALUE);
 509   *result = NULL;
 510   *resultlen = 0;
 511
 512   sw = apdu_send (slot, 0,
 513                   0x00, CMD_PSO, 0x9E, 0x9A, datalen, (const char*)data,
 514                   result, resultlen);
 515   if (sw != SW_SUCCESS)
 516     {
 517       /* Make sure that pending buffers are released. */
 518       xfree (*result);
 519       *result = NULL;
 520       *resultlen = 0;
 521       return map_sw (sw);
 522     }
 523
 524   return 0;
 525 }
 526
 527
 528 /* Perform the security operation DECIPHER.  PADIND is the padding
 529    indicator to be used.  It should be 0 if no padding is required, a
 530    value of -1 suppresses the padding byte.  On success 0 is returned
 531    and the plaintext is available in a newly allocated buffer stored
 532    at RESULT with its length stored at RESULTLEN. */
 533 gpg_error_t
 534 iso7816_decipher (int slot, int extended_mode,
 535                   const unsigned char *data, size_t datalen,
 536                   int padind, unsigned char **result, size_t *resultlen)
 537 {
 538   int sw;
 539   unsigned char *buf;
 540
 541   if (!data || !datalen || !result || !resultlen)
 542     return gpg_error (GPG_ERR_INV_VALUE);
 543   *result = NULL;
 544   *resultlen = 0;
 545
 546   if (padind >= 0)
 547     {
 548       /* We need to prepend the padding indicator. */
 549       buf = xtrymalloc (datalen + 1);
 550       if (!buf)
 551         return gpg_error (gpg_err_code_from_errno (errno));
 552
 553       *buf = padind; /* Padding indicator. */
 554       memcpy (buf+1, data, datalen);
 555       sw = apdu_send (slot, extended_mode,
 556                       0x00, CMD_PSO, 0x80, 0x86,
 557                       datalen+1, (char*)buf,
 558                       result, resultlen);
 559       xfree (buf);
 560     }
 561   else
 562     {
 563       sw = apdu_send (slot, extended_mode,
 564                       0x00, CMD_PSO, 0x80, 0x86,
 565                       datalen, (const char *)data,
 566                       result, resultlen);
 567     }
 568   if (sw != SW_SUCCESS)
 569     {
 570       /* Make sure that pending buffers are released. */
 571       xfree (*result);
 572       *result = NULL;
 573       *resultlen = 0;
 574       return map_sw (sw);
 575     }
 576
 577   return 0;
 578 }
 579
 580
 581 gpg_error_t
 582 iso7816_internal_authenticate (int slot,
 583                                const unsigned char *data, size_t datalen,
 584                                unsigned char **result, size_t *resultlen)
 585 {
 586   int sw;
 587
 588   if (!data || !datalen || !result || !resultlen)
 589     return gpg_error (GPG_ERR_INV_VALUE);
 590   *result = NULL;
 591   *resultlen = 0;
 592
 593   sw = apdu_send (slot, 0, 0x00, CMD_INTERNAL_AUTHENTICATE, 0, 0,
 594                   datalen, (const char*)data,  result, resultlen);
 595   if (sw != SW_SUCCESS)
 596     {
 597       /* Make sure that pending buffers are released. */
 598       xfree (*result);
 599       *result = NULL;
 600       *resultlen = 0;
 601       return map_sw (sw);
 602     }
 603
 604   return 0;
 605 }
 606
 607
 608 static gpg_error_t
 609 do_generate_keypair (int slot, int readonly,
 610                   const unsigned char *data, size_t datalen,
 611                   unsigned char **result, size_t *resultlen)
 612 {
 613   int sw;
 614
 615   if (!data || !datalen || !result || !resultlen)
 616     return gpg_error (GPG_ERR_INV_VALUE);
 617   *result = NULL;
 618   *resultlen = 0;
 619
 620   sw = apdu_send (slot, 0,
 621                   0x00, CMD_GENERATE_KEYPAIR, readonly? 0x81:0x80, 0,
 622                   datalen, (const char*)data,  result, resultlen);
 623   if (sw != SW_SUCCESS)
 624     {
 625       /* Make sure that pending buffers are released. */
 626       xfree (*result);
 627       *result = NULL;
 628       *resultlen = 0;
 629       return map_sw (sw);
 630     }
 631
 632   return 0;
 633 }
 634
 635
 636 gpg_error_t
 637 iso7816_generate_keypair (int slot,
 638                           const unsigned char *data, size_t datalen,
 639                           unsigned char **result, size_t *resultlen)
 640 {
 641   return do_generate_keypair (slot, 0, data, datalen, result, resultlen);
 642 }
 643
 644
 645 gpg_error_t
 646 iso7816_read_public_key (int slot,
 647                           const unsigned char *data, size_t datalen,
 648                           unsigned char **result, size_t *resultlen)
 649 {
 650   return do_generate_keypair (slot, 1, data, datalen, result, resultlen);
 651 }
 652
 653
 654
 655 gpg_error_t
 656 iso7816_get_challenge (int slot, int length, unsigned char *buffer)
 657 {
 658   int sw;
 659   unsigned char *result;
 660   size_t resultlen, n;
 661
 662   if (!buffer || length < 1)
 663     return gpg_error (GPG_ERR_INV_VALUE);
 664
 665   do
 666     {
 667       result = NULL;
 668       n = length > 254? 254 : length;
 669       sw = apdu_send_le (slot, 0,
 670                          0x00, CMD_GET_CHALLENGE, 0, 0, -1, NULL, n,
 671                          &result, &resultlen);
 672       if (sw != SW_SUCCESS)
 673         {
 674           /* Make sure that pending buffers are released. */
 675           xfree (result);
 676           return map_sw (sw);
 677         }
 678       if (resultlen > n)
 679         resultlen = n;
 680       memcpy (buffer, result, resultlen);
 681       buffer += resultlen;
 682       length -= resultlen;
 683       xfree (result);
 684     }
 685   while (length > 0);
 686
 687   return 0;
 688 }
 689
 690 /* Perform a READ BINARY command requesting a maximum of NMAX bytes
 691    from OFFSET.  With NMAX = 0 the entire file is read. The result is
 692    stored in a newly allocated buffer at the address passed by RESULT.
 693    Returns the length of this data at the address of RESULTLEN. */
 694 gpg_error_t
 695 iso7816_read_binary (int slot, size_t offset, size_t nmax,
 696                      unsigned char **result, size_t *resultlen)
 697 {
 698   int sw;
 699   unsigned char *buffer;
 700   size_t bufferlen;
 701   int read_all = !nmax;
 702   size_t n;
 703
 704   if (!result || !resultlen)
 705     return gpg_error (GPG_ERR_INV_VALUE);
 706   *result = NULL;
 707   *resultlen = 0;
 708
 709   /* We can only encode 15 bits in p0,p1 to indicate an offset. Thus
 710      we check for this limit. */
 711   if (offset > 32767)
 712     return gpg_error (GPG_ERR_INV_VALUE);
 713
 714   do
 715     {
 716       buffer = NULL;
 717       bufferlen = 0;
 718       n = read_all? 0 : nmax;
 719       sw = apdu_send_le (slot, 0, 0x00, CMD_READ_BINARY,
 720                          ((offset>>8) & 0xff), (offset & 0xff) , -1, NULL,
 721                          n, &buffer, &bufferlen);
 722       if ( SW_EXACT_LENGTH_P(sw) )
 723         {
 724           n = (sw & 0x00ff);
 725           sw = apdu_send_le (slot, 0, 0x00, CMD_READ_BINARY,
 726                              ((offset>>8) & 0xff), (offset & 0xff) , -1, NULL,
 727                              n, &buffer, &bufferlen);
 728         }
 729
 730       if (*result && sw == SW_BAD_P0_P1)
 731         {
 732           /* Bad Parameter means that the offset is outside of the
 733              EF. When reading all data we take this as an indication
 734              for EOF.  */
 735           break;
 736         }
 737
 738       if (sw != SW_SUCCESS && sw != SW_EOF_REACHED)
 739         {
 740           /* Make sure that pending buffers are released. */
 741           xfree (buffer);
 742           xfree (*result);
 743           *result = NULL;
 744           *resultlen = 0;
 745           return map_sw (sw);
 746         }
 747       if (*result) /* Need to extend the buffer. */
 748         {
 749           unsigned char *p = xtryrealloc (*result, *resultlen + bufferlen);
 750           if (!p)
 751             {
 752               gpg_error_t err = gpg_error_from_syserror ();
 753               xfree (buffer);
 754               xfree (*result);
 755               *result = NULL;
 756               *resultlen = 0;
 757               return err;
 758             }
 759           *result = p;
 760           memcpy (*result + *resultlen, buffer, bufferlen);
 761           *resultlen += bufferlen;
 762           xfree (buffer);
 763           buffer = NULL;
 764         }
 765       else /* Transfer the buffer into our result. */
 766         {
 767           *result = buffer;
 768           *resultlen = bufferlen;
 769         }
 770       offset += bufferlen;
 771       if (offset > 32767)
 772         break; /* We simply truncate the result for too large
 773                   files. */
 774       if (nmax > bufferlen)
 775         nmax -= bufferlen;
 776       else
 777         nmax = 0;
 778     }
 779   while ((read_all && sw != SW_EOF_REACHED) || (!read_all && nmax));
 780
 781   return 0;
 782 }
 783
 784 /* Perform a READ RECORD command. RECNO gives the record number to
 785    read with 0 indicating the current record.  RECCOUNT must be 1 (not
 786    all cards support reading of more than one record).  SHORT_EF
 787    should be 0 to read the current EF or contain a short EF. The
 788    result is stored in a newly allocated buffer at the address passed
 789    by RESULT.  Returns the length of this data at the address of
 790    RESULTLEN. */
 791 gpg_error_t
 792 iso7816_read_record (int slot, int recno, int reccount, int short_ef,
 793                      unsigned char **result, size_t *resultlen)
 794 {
 795   int sw;
 796   unsigned char *buffer;
 797   size_t bufferlen;
 798
 799   if (!result || !resultlen)
 800     return gpg_error (GPG_ERR_INV_VALUE);
 801   *result = NULL;
 802   *resultlen = 0;
 803
 804   /* We can only encode 15 bits in p0,p1 to indicate an offset. Thus
 805      we check for this limit. */
 806   if (recno < 0 || recno > 255 || reccount != 1
 807       || short_ef < 0 || short_ef > 254 )
 808     return gpg_error (GPG_ERR_INV_VALUE);
 809
 810   buffer = NULL;
 811   bufferlen = 0;
 812   sw = apdu_send_le (slot, 0, 0x00, CMD_READ_RECORD,
 813                      recno,
 814                      short_ef? short_ef : 0x04,
 815                      -1, NULL,
 816                      0, &buffer, &bufferlen);
 817
 818   if (sw != SW_SUCCESS && sw != SW_EOF_REACHED)
 819     {
 820       /* Make sure that pending buffers are released. */
 821       xfree (buffer);
 822       xfree (*result);
 823       *result = NULL;
 824       *resultlen = 0;
 825       return map_sw (sw);
 826     }
 827   *result = buffer;
 828   *resultlen = bufferlen;
 829
 830   return 0;
 831 }
 832