| | 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 | // ISO15693 CRC & other commons |
| | 7 | //----------------------------------------------------------------------------- |
| | 8 | |
| | 9 | |
| | 10 | #include "proxmark3.h" |
| | 11 | #include <stdint.h> |
| | 12 | #include <stdlib.h> |
| | 13 | //#include "iso15693tools.h" |
| | 14 | |
| | 15 | #define POLY 0x8408 |
| | 16 | |
| | 17 | |
| | 18 | // The CRC as described in ISO 15693-Part 3-Annex C |
| | 19 | // v buffer with data |
| | 20 | // n length |
| | 21 | // returns crc as 16bit value |
| | 22 | uint16_t Iso15693Crc(uint8_t *v, int n) |
| | 23 | { |
| | 24 | uint32_t reg; |
| | 25 | int i, j; |
| | 26 | |
| | 27 | reg = 0xffff; |
| | 28 | for(i = 0; i < n; i++) { |
| | 29 | reg = reg ^ ((uint32_t)v[i]); |
| | 30 | for (j = 0; j < 8; j++) { |
| | 31 | if (reg & 0x0001) { |
| | 32 | reg = (reg >> 1) ^ 0x8408; |
| | 33 | } else { |
| | 34 | reg = (reg >> 1); |
| | 35 | } |
| | 36 | } |
| | 37 | } |
| | 38 | |
| | 39 | return ~(uint16_t)(reg & 0xffff); |
| | 40 | } |
| | 41 | |
| | 42 | // adds a CRC to a dataframe |
| | 43 | // req[] iso15963 frame without crc |
| | 44 | // n length without crc |
| | 45 | // returns the new length of the dataframe. |
| | 46 | int Iso15693AddCrc(uint8_t *req, int n) { |
| | 47 | uint16_t crc=Iso15693Crc(req,n); |
| | 48 | req[n] = crc & 0xff; |
| | 49 | req[n+1] = crc >> 8; |
| | 50 | return n+2; |
| | 51 | } |
| | 52 | |
| | 53 | |
| | 54 | int sprintf(char *str, const char *format, ...); |
| | 55 | |
| | 56 | // returns a string representation of the UID |
| | 57 | // UID is transmitted and stored LSB first, displayed MSB first |
| | 58 | // target char* buffer, where to put the UID, if NULL a static buffer is returned |
| | 59 | // uid[] the UID in transmission order |
| | 60 | // return: ptr to string |
| | 61 | char* Iso15693sprintUID(char *target,uint8_t *uid) { |
| | 62 | static char tempbuf[2*8+1]=""; |
| | 63 | if (target==NULL) target=tempbuf; |
| | 64 | sprintf(target,"%02X%02X%02X%02X%02X%02X%02X%02X", |
| | 65 | uid[7],uid[6],uid[5],uid[4],uid[3],uid[2],uid[1],uid[0]); |
| | 66 | return target; |
| | 67 | } |
| | 68 | |
| | 69 | uint16_t iclass_crc16(char *data_p, unsigned short length) |
| | 70 | { |
| | 71 | unsigned char i; |
| | 72 | unsigned int data; |
| | 73 | uint16_t crc = 0xffff; |
| | 74 | |
| | 75 | if (length == 0) |
| | 76 | return (~crc); |
| | 77 | |
| | 78 | do |
| | 79 | { |
| | 80 | for (i=0, data=(unsigned int)0xff & *data_p++; |
| | 81 | i < 8; |
| | 82 | i++, data >>= 1) |
| | 83 | { |
| | 84 | if ((crc & 0x0001) ^ (data & 0x0001)) |
| | 85 | crc = (crc >> 1) ^ POLY; |
| | 86 | else crc >>= 1; |
| | 87 | } |
| | 88 | } while (--length); |
| | 89 | |
| | 90 | crc = ~crc; |
| | 91 | data = crc; |
| | 92 | crc = (crc << 8) | (data >> 8 & 0xff); |
| | 93 | crc = crc ^ 0xBC3; |
| | 94 | return (crc); |
| | 95 | } |
| | 96 | |
projects / proxmark3-svn / blame_incremental