git.zerfleddert.de Git - proxmark3-svn/blob - common/wiegand.c

   1 //-----------------------------------------------------------------------------
   2 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   3 // at your option, any later version. See the LICENSE.txt file for the text of
   4 // the license.
   5 //-----------------------------------------------------------------------------
   6 // Wiegand functions
   7 //-----------------------------------------------------------------------------
   8
   9 #include "wiegand.h"
  10
  11 /*
  12 * @brief getParity
  13 * @param bits     pointer to the source bitstream of binary values 0|1
  14 * @param len      how long shall parity be calculated
  15 * @param type     use the defined values  EVEN|ODD
  16 * @return parity bit required to match type
  17 */
  18 uint8_t getParity( uint8_t *bits, uint8_t len, uint8_t type ) {
  19     uint8_t x = 0;
  20     for(; len > 0; --len)
  21         x += bits[len - 1];
  22
  23     return (x & 1 ) ^ type;
  24 }
  25
  26 // by marshmellow
  27 /* pass bits to be tested in bits, length bits passed in bitLen, and parity type EVEN|ODD in type
  28 * @brief checkParity
  29 * @param bits     pointer to the source bitstream of binary values 0|1
  30 * @param len      number of bits to be checked
  31 * @param type     use the defined values  EVEN|ODD
  32 * @return 1 if passed
  33 */
  34 uint8_t checkParity(uint32_t bits, uint8_t len, uint8_t type);
  35
  36 // by marshmellow
  37 // takes a array of binary values, start position, length of bits per parity (includes parity bit),
  38 // Parity Type (1 for odd; 0 for even; 2 for Always 1's; 3 for Always 0's), and binary Length (length to run)
  39 size_t removeParity(uint8_t *bitstream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen) {
  40         uint32_t parityWd = 0;
  41         size_t j = 0, bitcount = 0;
  42         for (int word = 0; word < (bLen); word += pLen){
  43                 for (int bit = 0; bit < pLen; ++bit){
  44                         parityWd = (parityWd << 1) | bitstream[startIdx+word+bit];
  45                         bitstream[j++] = (bitstream[startIdx + word + bit]);
  46                 }
  47                 j--; // overwrite parity with next data
  48                 // if parity fails then return 0
  49                 switch (pType) {
  50                         case 3: if (bitstream[j] == 1) return 0; break; //should be 0 spacer bit
  51                         case 2: if (bitstream[j] == 0) return 0; break; //should be 1 spacer bit
  52                         default: //test parity
  53                                 if (parityTest(parityWd, pLen, pType) == 0) return 0; break;
  54                 }
  55                 bitcount += ( pLen - 1 );
  56                 parityWd = 0;
  57         }
  58         // if we got here then all the parities passed
  59         //return ID start index and size
  60         return bitcount;
  61 }
  62
  63
  64 // by marshmellow
  65 // takes a array of binary values, length of bits per parity (includes parity bit),
  66 // Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run)
  67 // Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added
  68 /*
  69 * @brief addParity
  70 * @param bits       pointer to the source bitstream of binary values
  71 * @param dest       pointer to the destination where parities together with bits are added.
  72 * @param sourceLen  number of
  73 * @param pLen       length bits to be checked
  74 * @param pType      EVEN|ODD|2 (always 1's)|3 (always 0's)
  75 * @return
  76 */
  77 size_t addParity(uint8_t *bits, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType)
  78 {
  79         uint32_t parityWd = 0;
  80         size_t j = 0, bitCnt = 0;
  81         for (int word = 0; word < sourceLen; word += pLen-1) {
  82                 for (int bit = 0; bit < pLen-1; ++bit){
  83                         parityWd = (parityWd << 1) | bits[word+bit];
  84                         dest[j++] = (bits[word+bit]);
  85                 }
  86
  87                 // if parity fails then return 0
  88                 switch (pType) {
  89                         case 3: dest[j++] = 0; break; // marker bit which should be a 0
  90                         case 2: dest[j++] = 1; break; // marker bit which should be a 1
  91                         default:
  92                                 dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1;
  93                                 break;
  94                 }
  95                 bitCnt += pLen;
  96                 parityWd = 0;
  97         }
  98         // if we got here then all the parities passed
  99         //return ID start index and size
 100         return bitCnt;
 101 }
 102
 103 // by marshmellow
 104 /*
 105 *  add HID parity to binary array: EVEN prefix for 1st half of ID, ODD suffix for 2nd half
 106 * @brief wiegand_add_parity
 107 * @param source  pointer to source of binary data
 108 * @param dest    pointer to the destination where wiegandparity has been appended
 109 * @param len     number of bits which wiegand parity shall be calculated over. This number is without parities, so a wiegand 26 has 24 bits of data
 110 */
 111 void wiegand_add_parity(uint8_t *source, uint8_t *dest, uint8_t len) {
 112
 113         // Copy to destination, shifted one step to make room for EVEN parity
 114     memcpy(dest+1, source, length);
 115
 116         // half length, Even and Odd is calculated to the middle.
 117         uint8_t len_h2 = length >> 1;
 118
 119         // add EVEN parity at the beginning
 120     *(dest) = GetParity(source, EVEN, len_h2);
 121
 122     dest += length + 1;
 123
 124         // add ODD parity at the very end
 125     *(dest) = GetParity(source + len_h2, ODD, len_h2);
 126 }
 127
 128 //uint32_t bytebits_to_byte(uint8_t* src, size_t numbits);
 129 #define MAX_BITS_TXX55 6*4*8
 130 #define MAX_BYTES_TXX55 6*4
 131 /*
 132 * @brief num_to_wiegand_bytes
 133 * @param oem       Sometimes call FF Fixfield, SiteCode. Used in a few formats
 134 * @param fc        Facility code
 135 * @param cn        Card number
 136 * @param dest      pointer to the destination where wiegand bytes will be stored
 137 * @param formatlen
 138 */
 139 void num_to_wiegand_bytes(uint64_t oem, uint64_t fc, uint64_t cn, uint8_t *dest, uint8_t formatlen){
 140
 141         uint8_t data[MAX_BITS_TXX55] = {0};
 142         memset(data, 0, sizeof(data));
 143
 144         num_to_wiegand_bits(oem, fc, cn, data, formatlen);
 145
 146         // loop
 147         // (formatlen / 32 ) + 1
 148         // (formatlen >> 5) + 1
 149         for (int i = 0; i < formatlen ; ++i){
 150                 uint32_t value  = bytebits_to_byte( data + (i * 32), 32);
 151                 num_to_bytes(value, 32, dest + (i*4) );
 152         }
 153
 154 }
 155 /*
 156 * @brief num_to_wiegand_bits
 157 * @param oem       Sometimes call FF Fixfield, SiteCode. Used in a few formats
 158 * @param fc        Facility code
 159 * @param cn        Card number
 160 * @param dest      pointer to the destination where wiegand bits will be stored
 161 * @param formatlen
 162 */
 163 void num_to_wiegand_bits(uint64_t oem, uint64_t fc, uint64_t cn, uint8_t *dest, uint8_t formatlen){
 164
 165         uint8_t bits[MAX_BITS_TXX55] = {0};
 166         memset(bits, 0, sizeof(bits));
 167         uint8_t *temp = bits;
 168         uint64_t value = 0;
 169
 170         switch ( formatlen ){
 171                 case 26 :                               // 26bit HID H10301
 172                         fc &= 0xFF;                     // 8bits
 173                         cn &= 0xFFFF;           // 16bits
 174                         value = fc << 16 | cn;
 175                         num_to_bytebits(value, 24, temp);
 176                         wiegand_add_parity(temp, dest, 24);
 177                         break;
 178                 case 261:                               // 26bit Indala
 179                         fc &= 0xFFF;            // 12bits
 180                         cn &= 0xFFF;            // 12bits
 181                         value = fc << 12 | cn;
 182                         num_to_bytebits(value, 24, temp);
 183                         wiegand_add_parity(temp, dest, 24);
 184                         break;
 185                 case 34 :                               // 34bits HID
 186                         fc &= 0xFFFF;           // 16bits
 187                         cn &= 0xFFFF;           // 16bits
 188                         value = fc << 16 | cn;
 189                         num_to_bytebits(value, 32, temp);
 190                         wiegand_add_parity(temp, dest, 32);
 191                         break;
 192                 case 35 :                               // 35bits HID
 193                         fc &= 0xFFF;            // 12bits
 194                         cn &= 0xFFFFFF;         // 20bits
 195                         value = fc << 20 | cn;
 196                         num_to_bytebits(value, 32, temp);
 197                         wiegand_add_parity(temp, dest, 32);
 198                         break;
 199                 case 37 :                               // H10304
 200                         fc &= 0xFFFF;           // 16bits
 201                         cn &= 0x7FFFF;          // 19bits
 202                         value = fc << 19 | cn;
 203                         num_to_bytebits(value, 35, temp);
 204                         wiegand_add_parity(temp, dest, 35);
 205                         break;
 206                 case 39 :                               // 39bit KERI System Pyramid
 207                         fc &= 0x1FFFF;          // 17bits
 208                         cn &= 0xFFFFFFFF;       // 20bits
 209                         value = fc << 20 | cn;
 210                         num_to_bytebits(value, 37, temp);
 211                         wiegand_add_parity(temp, dest, 37);
 212                         break;
 213                 case 44 :                               // 44bit KERI system Pyramid
 214                         oem &= 0xFF;            // 8bits
 215                         fc &= 0xFFF;            // 12bits
 216                         cn &= 0xFFFFFFFF;       // 21bits
 217                         value = oem << 20 | fc << 12 | cn;
 218                         num_to_bytebits(value, 42, temp);
 219                         wiegand_add_parity(temp, dest, 42);
 220                         break;
 221                 case 50 :                               // AWID 50 RBH
 222                         fc &= 0xFFFF;           // 16bits
 223                         cn &= 0xFFFFFFFF        // 32bits
 224                         value = fc << 32 | cn;
 225                         num_to_bytebits(value, 48, temp);
 226                         wiegand_add_parity(temp, dest, 48);  // verify!
 227                         break;
 228                 default:
 229                         break;
 230         }
 231 }