examples/PCSCv2part10.c

   1 /*
   2     PCSCv2part10.c: helper functions for PC/SC v2 part 10 services
   3     Copyright (C) 2012   Ludovic Rousseau
   4
   5     This library is free software; you can redistribute it and/or
   6     modify it under the terms of the GNU Lesser General Public
   7     License as published by the Free Software Foundation; either
   8     version 2.1 of the License, or (at your option) any later version.
   9
  10     This library is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13     Lesser General Public License for more details.
  14
  15     You should have received a copy of the GNU Lesser General Public
  16     License along with this library; if not, write to the Free Software
  17     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  18 */
  19
  20 #include <stdio.h>
  21 #include <arpa/inet.h>
  22
  23 #ifdef __APPLE__
  24 #include <PCSC/winscard.h>
  25 #include <PCSC/wintypes.h>
  26 #else
  27 #include <winscard.h>
  28 #endif
  29
  30 #include "PCSCv2part10.h"
  31
  32 int PCSCv2Part10_find_TLV_property_by_tag_from_buffer(
  33         unsigned char *buffer, int length, int property, int * value_int)
  34 {
  35         unsigned char *p;
  36         int found = 0, len;
  37         int value = -1;
  38         int ret = -1;   /* not found by default */
  39
  40         p = buffer;
  41         while (p-buffer < length)
  42         {
  43                 if (*p++ == property)
  44                 {
  45                         found = 1;
  46                         break;
  47                 }
  48
  49                 /* go to next tag */
  50                 len = *p++;
  51                 p += len;
  52         }
  53
  54         if (found)
  55         {
  56                 len = *p++;
  57                 ret = 0;
  58
  59                 switch(len)
  60                 {
  61                         case 1:
  62                                 value = *p;
  63                                 break;
  64                         case 2:
  65                                 value = *p + (*(p+1)<<8);
  66                                 break;
  67                         case 4:
  68                                 value = *p + (*(p+1)<<8) + (*(p+2)<<16) + (*(p+3)<<24);
  69                                 break;
  70                         default:
  71                                 /* wrong length for an integer */
  72                                 ret = -2;
  73                 }
  74         }
  75
  76         if (value_int)
  77                 *value_int = value;
  78
  79         return ret;
  80 } /* PCSCv2Part10_find_TLV_property_by_tag_from_buffer */
  81
  82 int PCSCv2Part10_find_TLV_property_by_tag_from_hcard(SCARDHANDLE hCard,
  83         int property, int * value)
  84 {
  85         unsigned char buffer[MAX_BUFFER_SIZE];
  86         LONG rv;
  87         DWORD length;
  88         unsigned int i;
  89         PCSC_TLV_STRUCTURE *pcsc_tlv;
  90         DWORD properties_in_tlv_ioctl;
  91         int found;
  92
  93         rv = SCardControl(hCard, CM_IOCTL_GET_FEATURE_REQUEST, NULL, 0,
  94                 buffer, sizeof buffer, &length);
  95         if (rv != SCARD_S_SUCCESS)
  96                 return -1;
  97
  98         /* get the number of elements instead of the complete size */
  99         length /= sizeof(PCSC_TLV_STRUCTURE);
 100
 101         pcsc_tlv = (PCSC_TLV_STRUCTURE *)buffer;
 102         found = 0;
 103         for (i = 0; i < length; i++)
 104         {
 105                 if (FEATURE_GET_TLV_PROPERTIES == pcsc_tlv[i].tag)
 106                 {
 107                         properties_in_tlv_ioctl = ntohl(pcsc_tlv[i].value);
 108                         found = 1;
 109                 }
 110         }
 111
 112         if (! found)
 113                 return -3;
 114
 115         rv= SCardControl(hCard, properties_in_tlv_ioctl, NULL, 0,
 116                 buffer, sizeof buffer, &length);
 117         if (rv != SCARD_S_SUCCESS)
 118                 return -1;
 119
 120         return PCSCv2Part10_find_TLV_property_by_tag_from_buffer(buffer,
 121                 length, property, value);
 122 }
 123