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7fe9b0b7 | 1 | #include <stdio.h> |
2 | #include <stdlib.h> | |
3 | #include <string.h> | |
4 | #include <stdint.h> | |
5 | #include "proxusb.h" | |
6 | #include "data.h" | |
7 | #include "graph.h" | |
8 | #include "ui.h" | |
9 | #include "cmdparser.h" | |
10 | #include "cmdhf15.h" | |
11 | ||
12 | static int CmdHelp(const char *Cmd); | |
13 | ||
14 | static uint16_t Iso15693Crc(uint8_t *v, int n) | |
15 | { | |
16 | uint32_t reg; | |
17 | int i, j; | |
18 | ||
19 | reg = 0xffff; | |
20 | for (i = 0; i < n; i++) { | |
21 | reg = reg ^ ((uint32_t)v[i]); | |
22 | for (j = 0; j < 8; j++) { | |
23 | if (reg & 0x0001) { | |
24 | reg = (reg >> 1) ^ 0x8408; | |
25 | } else { | |
26 | reg = (reg >> 1); | |
27 | } | |
28 | } | |
29 | } | |
30 | ||
31 | return (uint16_t)~reg; | |
32 | } | |
33 | ||
34 | int CmdHF15Demod(const char *Cmd) | |
35 | { | |
36 | // The sampling rate is 106.353 ksps/s, for T = 18.8 us | |
37 | ||
38 | // SOF defined as | |
39 | // 1) Unmodulated time of 56.64us | |
40 | // 2) 24 pulses of 423.75khz | |
41 | // 3) logic '1' (unmodulated for 18.88us followed by 8 pulses of 423.75khz) | |
42 | ||
43 | static const int FrameSOF[] = { | |
44 | -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, | |
46 | 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, | |
48 | -1, -1, -1, -1, | |
49 | -1, -1, -1, -1, | |
50 | 1, 1, 1, 1, | |
51 | 1, 1, 1, 1 | |
52 | }; | |
53 | static const int Logic0[] = { | |
54 | 1, 1, 1, 1, | |
55 | 1, 1, 1, 1, | |
56 | -1, -1, -1, -1, | |
57 | -1, -1, -1, -1 | |
58 | }; | |
59 | static const int Logic1[] = { | |
60 | -1, -1, -1, -1, | |
61 | -1, -1, -1, -1, | |
62 | 1, 1, 1, 1, | |
63 | 1, 1, 1, 1 | |
64 | }; | |
65 | ||
66 | // EOF defined as | |
67 | // 1) logic '0' (8 pulses of 423.75khz followed by unmodulated for 18.88us) | |
68 | // 2) 24 pulses of 423.75khz | |
69 | // 3) Unmodulated time of 56.64us | |
70 | ||
71 | static const int FrameEOF[] = { | |
72 | 1, 1, 1, 1, | |
73 | 1, 1, 1, 1, | |
74 | -1, -1, -1, -1, | |
75 | -1, -1, -1, -1, | |
76 | 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
77 | 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
78 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, | |
79 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 | |
80 | }; | |
81 | ||
82 | int i, j; | |
83 | int max = 0, maxPos; | |
84 | ||
85 | int skip = 4; | |
86 | ||
87 | if (GraphTraceLen < 1000) return 0; | |
88 | ||
89 | // First, correlate for SOF | |
90 | for (i = 0; i < 100; i++) { | |
91 | int corr = 0; | |
92 | for (j = 0; j < arraylen(FrameSOF); j += skip) { | |
93 | corr += FrameSOF[j] * GraphBuffer[i + (j / skip)]; | |
94 | } | |
95 | if (corr > max) { | |
96 | max = corr; | |
97 | maxPos = i; | |
98 | } | |
99 | } | |
100 | PrintAndLog("SOF at %d, correlation %d", maxPos, | |
101 | max / (arraylen(FrameSOF) / skip)); | |
102 | ||
103 | i = maxPos + arraylen(FrameSOF) / skip; | |
104 | int k = 0; | |
105 | uint8_t outBuf[20]; | |
106 | memset(outBuf, 0, sizeof(outBuf)); | |
107 | uint8_t mask = 0x01; | |
108 | for (;;) { | |
109 | int corr0 = 0, corr1 = 0, corrEOF = 0; | |
110 | for (j = 0; j < arraylen(Logic0); j += skip) { | |
111 | corr0 += Logic0[j] * GraphBuffer[i + (j / skip)]; | |
112 | } | |
113 | for (j = 0; j < arraylen(Logic1); j += skip) { | |
114 | corr1 += Logic1[j] * GraphBuffer[i + (j / skip)]; | |
115 | } | |
116 | for (j = 0; j < arraylen(FrameEOF); j += skip) { | |
117 | corrEOF += FrameEOF[j] * GraphBuffer[i + (j / skip)]; | |
118 | } | |
119 | // Even things out by the length of the target waveform. | |
120 | corr0 *= 4; | |
121 | corr1 *= 4; | |
122 | ||
123 | if (corrEOF > corr1 && corrEOF > corr0) { | |
124 | PrintAndLog("EOF at %d", i); | |
125 | break; | |
126 | } else if (corr1 > corr0) { | |
127 | i += arraylen(Logic1) / skip; | |
128 | outBuf[k] |= mask; | |
129 | } else { | |
130 | i += arraylen(Logic0) / skip; | |
131 | } | |
132 | mask <<= 1; | |
133 | if (mask == 0) { | |
134 | k++; | |
135 | mask = 0x01; | |
136 | } | |
137 | if ((i + (int)arraylen(FrameEOF)) >= GraphTraceLen) { | |
138 | PrintAndLog("ran off end!"); | |
139 | break; | |
140 | } | |
141 | } | |
142 | if (mask != 0x01) { | |
143 | PrintAndLog("error, uneven octet! (discard extra bits!)"); | |
144 | PrintAndLog(" mask=%02x", mask); | |
145 | } | |
146 | PrintAndLog("%d octets", k); | |
147 | ||
148 | for (i = 0; i < k; i++) { | |
149 | PrintAndLog("# %2d: %02x ", i, outBuf[i]); | |
150 | } | |
151 | PrintAndLog("CRC=%04x", Iso15693Crc(outBuf, k - 2)); | |
152 | return 0; | |
153 | } | |
154 | ||
155 | int CmdHF15Read(const char *Cmd) | |
156 | { | |
157 | UsbCommand c = {CMD_ACQUIRE_RAW_ADC_SAMPLES_ISO_15693}; | |
158 | SendCommand(&c); | |
159 | return 0; | |
160 | } | |
161 | ||
162 | int CmdHF15Reader(const char *Cmd) | |
163 | { | |
164 | UsbCommand c = {CMD_READER_ISO_15693, {strtol(Cmd, NULL, 0), 0, 0}}; | |
165 | SendCommand(&c); | |
166 | return 0; | |
167 | } | |
168 | ||
169 | int CmdHF15Sim(const char *Cmd) | |
170 | { | |
171 | UsbCommand c = {CMD_SIMTAG_ISO_15693, {strtol(Cmd, NULL, 0), 0, 0}}; | |
172 | SendCommand(&c); | |
173 | return 0; | |
174 | } | |
175 | ||
176 | static command_t CommandTable[] = | |
177 | { | |
178 | {"help", CmdHelp, 1, "This help"}, | |
179 | {"demod", CmdHF15Demod, 1, "Demodulate ISO15693 from tag"}, | |
180 | {"read", CmdHF15Read, 0, "Read HF tag (ISO 15693)"}, | |
181 | {"reader", CmdHF15Reader, 0, "Act like an ISO15693 reader"}, | |
182 | {"sim", CmdHF15Sim, 0, "Fake an ISO15693 tag"}, | |
183 | {NULL, NULL, 0, NULL} | |
184 | }; | |
185 | ||
186 | int CmdHF15(const char *Cmd) | |
187 | { | |
188 | CmdsParse(CommandTable, Cmd); | |
189 | return 0; | |
190 | } | |
191 | ||
192 | int CmdHelp(const char *Cmd) | |
193 | { | |
194 | CmdsHelp(CommandTable); | |
195 | return 0; | |
196 | } |