gnupg/scd/card.c

/* card.c - SCdaemon card functions
 *	Copyright (C) 2002 Free Software Foundation, Inc.
 *
 * This file is part of GnuPG.
 *
 * GnuPG is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * GnuPG is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */

#include <config.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include <opensc-pkcs15.h>
#include <ksba.h>

#if SC_MAX_SEC_ATTR_SIZE < 36
# error This is not the patched OpenSC version
#endif

#include "scdaemon.h"
#include "card-common.h"

/* Map the SC error codes to the GNUPG ones */
int
map_sc_err (int rc)
{
  switch (rc)
    {
    case 0: rc = 0; break;
    case SC_ERROR_CMD_TOO_SHORT:         rc = GNUPG_Card_Error; break;
    case SC_ERROR_CMD_TOO_LONG:          rc = GNUPG_Card_Error; break;
    case SC_ERROR_NOT_SUPPORTED:         rc = GNUPG_Not_Supported; break;
    case SC_ERROR_TRANSMIT_FAILED:       rc = GNUPG_Card_Error; break;
    case SC_ERROR_FILE_NOT_FOUND:        rc = GNUPG_Card_Error; break;
    case SC_ERROR_INVALID_ARGUMENTS:     rc = GNUPG_Card_Error; break;
    case SC_ERROR_PKCS15_APP_NOT_FOUND:  rc = GNUPG_No_PKCS15_App; break;
    case SC_ERROR_REQUIRED_PARAMETER_NOT_FOUND: rc = GNUPG_Card_Error; break;
    case SC_ERROR_OUT_OF_MEMORY:         rc = GNUPG_Out_Of_Core; break;
    case SC_ERROR_NO_READERS_FOUND:      rc = GNUPG_Card_Error; break;
    case SC_ERROR_OBJECT_NOT_VALID:      rc = GNUPG_Card_Error; break;
    case SC_ERROR_ILLEGAL_RESPONSE:      rc = GNUPG_Card_Error; break;
    case SC_ERROR_PIN_CODE_INCORRECT:    rc = GNUPG_Card_Error; break;
    case SC_ERROR_SECURITY_STATUS_NOT_SATISFIED: rc = GNUPG_Card_Error; break;
    case SC_ERROR_CONNECTING_TO_RES_MGR: rc = GNUPG_Card_Error; break;
    case SC_ERROR_INVALID_ASN1_OBJECT:   rc = GNUPG_Card_Error; break;
    case SC_ERROR_BUFFER_TOO_SMALL:      rc = GNUPG_Card_Error; break;
    case SC_ERROR_CARD_NOT_PRESENT:      rc = GNUPG_Card_Not_Present; break;
    case SC_ERROR_RESOURCE_MANAGER:      rc = GNUPG_Card_Error; break;
    case SC_ERROR_CARD_REMOVED:          rc = GNUPG_Card_Removed; break;
    case SC_ERROR_INVALID_PIN_LENGTH:    rc = GNUPG_Card_Error; break;
    case SC_ERROR_UNKNOWN_SMARTCARD:     rc = GNUPG_Card_Error; break;
    case SC_ERROR_UNKNOWN_REPLY:         rc = GNUPG_Card_Error; break;
    case SC_ERROR_OBJECT_NOT_FOUND:      rc = GNUPG_Card_Error; break;
    case SC_ERROR_CARD_RESET:            rc = GNUPG_Card_Reset; break;
    case SC_ERROR_ASN1_OBJECT_NOT_FOUND: rc = GNUPG_Card_Error; break;
    case SC_ERROR_ASN1_END_OF_CONTENTS:  rc = GNUPG_Card_Error; break;
    case SC_ERROR_TOO_MANY_OBJECTS:      rc = GNUPG_Card_Error; break;
    case SC_ERROR_INVALID_CARD:          rc = GNUPG_Invalid_Card; break;
    case SC_ERROR_WRONG_LENGTH:          rc = GNUPG_Card_Error; break;
    case SC_ERROR_RECORD_NOT_FOUND:      rc = GNUPG_Card_Error; break;
    case SC_ERROR_INTERNAL:              rc = GNUPG_Card_Error; break;
    default: rc = GNUPG_Card_Error; break;
    }
  return rc;
}

/* Get the keygrip from CERT, return 0 on success */
int
card_help_get_keygrip (KsbaCert cert, unsigned char *array)
{
  GCRY_SEXP s_pkey;
  int rc;
  KsbaSexp p;
  size_t n;
  
  p = ksba_cert_get_public_key (cert);
  if (!p)
    return -1; /* oops */
  n = gcry_sexp_canon_len (p, 0, NULL, NULL);
  if (!n)
    return -1; /* libksba did not return a proper S-expression */
  rc = gcry_sexp_sscan ( &s_pkey, NULL, p, n);
  xfree (p);
  if (rc)
    return -1; /* can't parse that S-expression */
  array = gcry_pk_get_keygrip (s_pkey, array);
  gcry_sexp_release (s_pkey);
  if (!array)
    return -1; /* failed to calculate the keygrip */
  return 0;
}







/* Create a new context for the card and figures out some basic
   information of the card.  Detects whgether a PKCS_15 application is
   stored.

   Common errors: GNUPG_Card_Not_Present */
int
card_open (CARD *rcard)
{
  CARD card;
  int rc;

  card = xtrycalloc (1, sizeof *card);
  if (!card)
    return GNUPG_Out_Of_Core;
  card->reader = 0;
  
  rc = sc_establish_context (&card->ctx, "scdaemon");
  if (rc)
    {
      log_error ("failed to establish SC context: %s\n", sc_strerror (rc));
      rc = map_sc_err (rc);
      goto leave;
    }
  if (card->reader >= card->ctx->reader_count)
    {
      log_error ("no card reader available\n");
      rc = GNUPG_Card_Error;
      goto leave;
    }
  card->ctx->error_file = log_get_stream ();
  card->ctx->debug = opt.debug_sc;
  card->ctx->debug_file = log_get_stream ();

  if (sc_detect_card_presence (card->ctx->reader[card->reader], 0) != 1)
    {
      rc = GNUPG_Card_Not_Present;
      goto leave;
    }

  rc = sc_connect_card (card->ctx->reader[card->reader], 0, &card->scard);
  if (rc)
    {
      log_error ("failed to connect card in reader %d: %s\n",
                 card->reader, sc_strerror (rc));
      rc = map_sc_err (rc);
      goto leave;
    }
  if (opt.verbose)
    log_info ("connected to card in reader %d using driver `%s'\n",
              card->reader, card->scard->driver->name);

  rc = sc_lock (card->scard);
  if (rc)
    {
      log_error ("can't lock card in reader %d: %s\n",
                 card->reader, sc_strerror (rc));
      rc = map_sc_err (rc);
      goto leave;
    }

    
 leave:
  if (rc)
    card_close (card);
  else
    *rcard = card;
  return rc;
}


/* Close a card and release all resources */
void
card_close (CARD card)
{
  if (card)
    {
      if (card->p15card)
        {
          sc_pkcs15_unbind (card->p15card);
          card->p15card = NULL;
        }
      if (card->scard)
        {
          sc_unlock (card->scard);
          sc_disconnect_card (card->scard, 0);
          card->scard = NULL;
	}
      if (card->ctx)
        {
          sc_release_context (card->ctx);
          card->ctx = NULL;
        }
      xfree (card);
    }      
}



/* Retrieve the serial number and the time of the last update of the
   card.  The serial number is returned as a malloced string (hex
   encoded) in SERIAL and the time of update is returned in STAMP.
   If no update time is available the returned value is 0.  The serial
   is mandatory for a PKCS_15 application and an error will be
   returned if this value is not availbale.  For non-PKCS-15 cards a
   serial number is constructed by other means. Caller must free
   SERIAL unless the function returns an error. */
int 
card_get_serial_and_stamp (CARD card, char **serial, time_t *stamp)
{
  char *s;
  int rc;
  struct sc_path path;
  struct sc_file *file;
  unsigned char buf[12];
  int i;

  if (!card || !serial || !stamp)
    return GNUPG_Invalid_Value;

  *serial = NULL;
  *stamp = 0; /* not available */

  if (!card->fnc.initialized)
    {
      card->fnc.initialized = 1;
      /* The first use of this card tries to figure out the type of the card 
         and sets up the function pointers. */
      rc = sc_pkcs15_bind (card->scard, &card->p15card);
      if (rc)
        {
          if (rc != SC_ERROR_PKCS15_APP_NOT_FOUND)
            log_error ("binding of existing PKCS-15 failed in reader %d: %s\n",
                       card->reader, sc_strerror (rc));
          card->p15card = NULL;
          rc = 0;
        }
      if (card->p15card)
        card_p15_bind (card);
      else
        card_dinsig_bind (card);
      card->fnc.initialized = 1;
    }
      

  /* We should lookup the iso 7812-1 and 8583-3 - argh ISO
     practice is suppressing innovation - IETF rules!  So we
     always get the serialnumber from the 2F02 GDO file.  */
  /* FIXME: in case we can't parse the 2F02 EF and we have a P15 card,
     we should get the serial number from the respective P15 file */
  sc_format_path ("3F002F02", &path);
  rc = sc_select_file (card->scard, &path, &file);
  if (rc)
    {
      log_error ("sc_select_file failed: %s\n", sc_strerror (rc));
      return GNUPG_Card_Error;
    }
  if (file->type != SC_FILE_TYPE_WORKING_EF
      || file->ef_structure != SC_FILE_EF_TRANSPARENT)
    {
      log_error ("wrong type or structure of GDO file\n");
      sc_file_free (file);
      return GNUPG_Card_Error;
    }
  if (file->size != 12)
    { /* FIXME: Use a real parser */
      log_error ("unsupported size of GDO file\n");
      sc_file_free (file);
      return GNUPG_Card_Error;
    }
      
  rc = sc_read_binary (card->scard, 0, buf, DIM (buf), 0);
  sc_file_free (file);
  if (rc < 0) 
    {
      log_error ("error reading GDO file: %s\n", sc_strerror (rc));
      return GNUPG_Card_Error;
    }
  if (rc != file->size)
    {
      log_error ("short read on GDO file\n");
      return GNUPG_Card_Error;
    }
  if (buf[0] != 0x5a || buf[1] != 10)
    {
      log_error ("invalid structure of GDO file\n");
      return GNUPG_Card_Error;
    }
  *serial = s = xtrymalloc (21);
  if (!*serial)
    return GNUPG_Out_Of_Core;
  for (i=0; i < 10; i++, s += 2)
    sprintf (s, "%02X", buf[2+i]);
  return 0;
}


/* Enumerate all keypairs on the card and return the Keygrip as well
   as the internal identification of the key.  KEYGRIP must be a
   caller provided buffer with a size of 20 bytes which will receive
   the KEYGRIP of the keypair.  If KEYID is not NULL, it returns the
   ID field of the key in allocated memory; this is a string without
   spaces.  The function returns -1 when all keys have been
   enumerated.  Note that the error GNUPG_Missing_Certificate may be
   returned if there is just the private key but no public key (ie.e a
   certificate) available.  Applications might want to continue
   enumerating after this error.*/
int
card_enum_keypairs (CARD card, int idx,
                    unsigned char *keygrip,
                    char **keyid)
{
  int rc;

  if (keyid)
    *keyid = NULL;

  if (!card || !keygrip)
    return GNUPG_Invalid_Value;
  if (idx < 0)
    return GNUPG_Invalid_Index;
  if (!card->fnc.initialized)
    return GNUPG_Card_Not_Initialized;
  if (!card->fnc.enum_keypairs)
    return GNUPG_Unsupported_Operation;
  rc = card->fnc.enum_keypairs (card, idx, keygrip, keyid);
  if (opt.verbose)
    log_info ("card operation enum_keypairs result: %s\n",
              gnupg_strerror (rc));
  return rc;
}


/* Read the certificate identified by CERTIDSTR which is the
   hexadecimal encoded ID of the certificate, prefixed with the string
   "3F005015.". The certificate is return in DER encoded form in CERT
   and NCERT. */
int
card_read_cert (CARD card, const char *certidstr,
                unsigned char **cert, size_t *ncert)
{
  int rc;

  if (!card || !certidstr || !cert || !ncert)
    return GNUPG_Invalid_Value;
  if (!card->fnc.initialized)
    return GNUPG_Card_Not_Initialized;
  if (!card->fnc.read_cert)
    return GNUPG_Unsupported_Operation;
  rc = card->fnc.read_cert (card, certidstr, cert, ncert);
  if (opt.verbose)
    log_info ("card operation read_cert result: %s\n", gnupg_strerror (rc));
  return rc;
}


/* Create the signature and return the allocated result in OUTDATA.
   If a PIN is required the PINCB will be used to ask for the PIN; it
   should return the PIN in an allocated buffer and put it into PIN.  */
int 
card_sign (CARD card, const char *keyidstr, int hashalgo,
           int (pincb)(void*, const char *, char **),
           void *pincb_arg,
           const void *indata, size_t indatalen,
           void **outdata, size_t *outdatalen )
{
  int rc;

  if (!card || !indata || !indatalen || !outdata || !outdatalen || !pincb)
    return GNUPG_Invalid_Value;
  if (!card->fnc.initialized)
    return GNUPG_Card_Not_Initialized;
  if (!card->fnc.sign)
    return GNUPG_Unsupported_Operation;
  rc =  card->fnc.sign (card, keyidstr, hashalgo,
                        pincb, pincb_arg,
                        indata, indatalen,
                        outdata, outdatalen);
  if (opt.verbose)
    log_info ("card operation sign result: %s\n", gnupg_strerror (rc));
  return rc;
}


/* Create the signature and return the allocated result in OUTDATA.
   If a PIN is required the PINCB will be used to ask for the PIN; it
   should return the PIN in an allocated buffer and put it into PIN.  */
int 
card_decipher (CARD card, const char *keyidstr,
               int (pincb)(void*, const char *, char **),
               void *pincb_arg,
               const void *indata, size_t indatalen,
               void **outdata, size_t *outdatalen )
{
  int rc;

  if (!card || !indata || !indatalen || !outdata || !outdatalen || !pincb)
    return GNUPG_Invalid_Value;
  if (!card->fnc.initialized)
    return GNUPG_Card_Not_Initialized;
  if (!card->fnc.decipher)
    return GNUPG_Unsupported_Operation;
  rc =  card->fnc.decipher (card, keyidstr,
                            pincb, pincb_arg,
                            indata, indatalen,
                            outdata, outdatalen);
  if (opt.verbose)
    log_info ("card operation decipher result: %s\n", gnupg_strerror (rc));
  return rc;
}