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cvs.zerfleddert.de Git - proxmark3-svn/blob - client/cmdlfti.c
59f83f0873de3a01e83a96f5c37ff5027af9594f
1 //-----------------------------------------------------------------------------
2 // Copyright (C) 2010 iZsh <izsh at fail0verflow.com>
4 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
5 // at your option, any later version. See the LICENSE.txt file for the text of
7 //-----------------------------------------------------------------------------
8 // Low frequency TI commands
9 //-----------------------------------------------------------------------------
18 #include "cmdparser.h"
21 static int CmdHelp(const char *Cmd
);
23 int CmdTIDemod(const char *Cmd
)
26 f_s = 2000000; % sampling frequency
27 f_l = 123200; % low FSK tone
28 f_h = 134200; % high FSK tone
30 T_l = 119e-6; % low bit duration
31 T_h = 130e-6; % high bit duration
33 l = 2*pi*ones(1, floor(f_s*T_l))*(f_l/f_s);
34 h = 2*pi*ones(1, floor(f_s*T_h))*(f_h/f_s);
36 l = sign(sin(cumsum(l)));
37 h = sign(sin(cumsum(h)));
41 static const int LowTone
[] = {
42 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
43 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
44 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
45 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
46 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
47 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
48 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
49 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
50 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
51 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
52 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
53 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
54 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
55 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
56 1, 1, 1, 1, 1, 1, 1, 1, -1, -1
59 static const int HighTone
[] = {
60 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1,
61 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1,
62 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
63 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
64 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
65 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1,
66 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1,
67 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1,
68 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
69 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
70 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1,
71 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1,
72 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1,
73 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1,
74 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
75 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
76 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1,
77 1, 1, 1, 1, 1, 1, 1, 1
79 int lowLen
= sizeof(LowTone
)/sizeof(int);
80 int highLen
= sizeof(HighTone
)/sizeof(int);
81 int convLen
= (highLen
>lowLen
)?highLen
:lowLen
;
84 int lowSum
= 0, highSum
= 0;;
85 int lowTot
= 0, highTot
= 0;
87 for (i
= 0; i
< GraphTraceLen
- convLen
; i
++) {
91 for (j
= 0; j
< lowLen
; j
++) {
92 lowSum
+= LowTone
[j
]*GraphBuffer
[i
+j
];
94 for (j
= 0; j
< highLen
; j
++) {
95 highSum
+= HighTone
[j
]*GraphBuffer
[i
+j
];
97 lowSum
= abs((100*lowSum
) / lowLen
);
98 highSum
= abs((100*highSum
) / highLen
);
99 lowSum
= (lowSum
<0)?-lowSum
:lowSum
;
100 highSum
= (highSum
<0)?-highSum
:highSum
;
102 GraphBuffer
[i
] = (highSum
<< 16) | lowSum
;
105 for (i
= 0; i
< GraphTraceLen
- convLen
- 16; i
++) {
108 // 16 and 15 are f_s divided by f_l and f_h, rounded
109 for (j
= 0; j
< 16; j
++) {
110 lowTot
+= (GraphBuffer
[i
+j
] & 0xffff);
112 for (j
= 0; j
< 15; j
++) {
113 highTot
+= (GraphBuffer
[i
+j
] >> 16);
115 GraphBuffer
[i
] = lowTot
- highTot
;
118 GraphTraceLen
-= (convLen
+ 16);
120 RepaintGraphWindow();
122 // TI tag data format is 16 prebits, 8 start bits, 64 data bits,
123 // 16 crc CCITT bits, 8 stop bits, 15 end bits
125 // the 16 prebits are always low
126 // the 8 start and stop bits of a tag must match
127 // the start/stop prebits of a ro tag are 01111110
128 // the start/stop prebits of a rw tag are 11111110
129 // the 15 end bits of a ro tag are all low
130 // the 15 end bits of a rw tag match bits 15-1 of the data bits
132 // Okay, so now we have unsliced soft decisions;
133 // find bit-sync, and then get some bits.
134 // look for 17 low bits followed by 6 highs (common pattern for ro and rw tags)
135 int max
= 0, maxPos
= 0;
136 for (i
= 0; i
< 6000; i
++) {
139 // searching 17 consecutive lows
140 for (j
= 0; j
< 17*lowLen
; j
++) {
141 dec
-= GraphBuffer
[i
+j
];
143 // searching 7 consecutive highs
144 for (; j
< 17*lowLen
+ 6*highLen
; j
++) {
145 dec
+= GraphBuffer
[i
+j
];
153 // place a marker in the buffer to visually aid location
154 // of the start of sync
155 GraphBuffer
[maxPos
] = 800;
156 GraphBuffer
[maxPos
+1] = -800;
158 // advance pointer to start of actual data stream (after 16 pre and 8 start bits)
162 // place a marker in the buffer to visually aid location
163 // of the end of sync
164 GraphBuffer
[maxPos
] = 800;
165 GraphBuffer
[maxPos
+1] = -800;
167 PrintAndLog("actual data bits start at sample %d", maxPos
);
169 PrintAndLog("length %d/%d", highLen
, lowLen
);
171 uint8_t bits
[1+64+16+8+16];
172 bits
[sizeof(bits
)-1] = '\0';
174 uint32_t shift3
= 0x7e000000, shift2
= 0, shift1
= 0, shift0
= 0;
176 for (i
= 0; i
< arraylen(bits
)-1; i
++) {
180 for (j
= 0; j
< lowLen
; j
++) {
181 low
-= GraphBuffer
[maxPos
+j
];
183 for (j
= 0; j
< highLen
; j
++) {
184 high
+= GraphBuffer
[maxPos
+j
];
190 // bitstream arrives lsb first so shift right
197 // 128 bit right shift register
198 shift0
= (shift0
>>1) | (shift1
<< 31);
199 shift1
= (shift1
>>1) | (shift2
<< 31);
200 shift2
= (shift2
>>1) | (shift3
<< 31);
203 // place a marker in the buffer between bits to visually aid location
204 GraphBuffer
[maxPos
] = 800;
205 GraphBuffer
[maxPos
+1] = -800;
207 PrintAndLog("Info: raw tag bits = %s", bits
);
209 TagType
= (shift3
>>8)&0xff;
210 if ( TagType
!= ((shift0
>>16)&0xff) ) {
211 PrintAndLog("Error: start and stop bits do not match!");
214 else if (TagType
== 0x7e) {
215 PrintAndLog("Info: Readonly TI tag detected.");
218 else if (TagType
== 0xfe) {
219 PrintAndLog("Info: Rewriteable TI tag detected.");
221 // put 64 bit data into shift1 and shift0
222 shift0
= (shift0
>>24) | (shift1
<< 8);
223 shift1
= (shift1
>>24) | (shift2
<< 8);
225 // align 16 bit crc into lower half of shift2
226 shift2
= ((shift2
>>24) | (shift3
<< 8)) & 0x0ffff;
228 // align 16 bit "end bits" or "ident" into lower half of shift3
231 // only 15 bits compare, last bit of ident is not valid
232 if ( (shift3
^shift0
)&0x7fff ) {
233 PrintAndLog("Error: Ident mismatch!");
235 // WARNING the order of the bytes in which we calc crc below needs checking
236 // i'm 99% sure the crc algorithm is correct, but it may need to eat the
237 // bytes in reverse or something
240 crc
= update_crc16(crc
, (shift0
)&0xff);
241 crc
= update_crc16(crc
, (shift0
>>8)&0xff);
242 crc
= update_crc16(crc
, (shift0
>>16)&0xff);
243 crc
= update_crc16(crc
, (shift0
>>24)&0xff);
244 crc
= update_crc16(crc
, (shift1
)&0xff);
245 crc
= update_crc16(crc
, (shift1
>>8)&0xff);
246 crc
= update_crc16(crc
, (shift1
>>16)&0xff);
247 crc
= update_crc16(crc
, (shift1
>>24)&0xff);
248 PrintAndLog("Info: Tag data = %08X%08X", shift1
, shift0
);
249 if (crc
!= (shift2
&0xffff)) {
250 PrintAndLog("Error: CRC mismatch, calculated %04X, got ^04X", crc
, shift2
&0xffff);
252 PrintAndLog("Info: CRC %04X is good", crc
);
256 PrintAndLog("Unknown tag type.");
262 // read a TI tag and return its ID
263 int CmdTIRead(const char *Cmd
)
265 UsbCommand c
= {CMD_READ_TI_TYPE
};
270 // write new data to a r/w TI tag
271 int CmdTIWrite(const char *Cmd
)
273 UsbCommand c
= {CMD_WRITE_TI_TYPE
};
276 res
= sscanf(Cmd
, "0x%x 0x%x 0x%x ", &c
.arg
[0], &c
.arg
[1], &c
.arg
[2]);
277 if (res
== 2) c
.arg
[2]=0;
279 PrintAndLog("Please specify the data as two hex strings, optionally the CRC as a third");
285 static command_t CommandTable
[] =
287 {"help", CmdHelp
, 1, "This help"},
288 {"demod", CmdTIDemod
, 1, "Demodulate raw bits for TI-type LF tag"},
289 {"read", CmdTIRead
, 0, "Read and decode a TI 134 kHz tag"},
290 {"write", CmdTIWrite
, 0, "Write new data to a r/w TI 134 kHz tag"},
291 {NULL
, NULL
, 0, NULL
}
294 int CmdLFTI(const char *Cmd
)
296 CmdsParse(CommandTable
, Cmd
);
300 int CmdHelp(const char *Cmd
)
302 CmdsHelp(CommandTable
);