PCF7931: improved read code and implemented a simple password bruteforce (#745)
[proxmark3-svn] / client / cmdlfpcf7931.c
1 //-----------------------------------------------------------------------------
2 // Copyright (C) 2012 Chalk <chalk.secu at gmail.com>
3 // 2015 Dake <thomas.cayrou at gmail.com>
4 // 2018 sguerrini97 <sguerrini97 at gmail.com>
5
6 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
7 // at your option, any later version. See the LICENSE.txt file for the text of
8 // the license.
9 //-----------------------------------------------------------------------------
10 // Low frequency PCF7931 commands
11 //-----------------------------------------------------------------------------
12
13 #include "cmdlfpcf7931.h"
14
15 #include <stdio.h>
16 #include <string.h>
17 #include "comms.h"
18 #include "ui.h"
19 #include "util.h"
20 #include "graph.h"
21 #include "cmdparser.h"
22 #include "cmddata.h"
23 #include "cmdmain.h"
24 #include "cmdlf.h"
25
26 static int CmdHelp(const char *Cmd);
27
28 #define PCF7931_DEFAULT_INITDELAY 17500
29 #define PCF7931_DEFAULT_OFFSET_WIDTH 0
30 #define PCF7931_DEFAULT_OFFSET_POSITION 0
31
32 // Default values - Configuration
33 struct pcf7931_config configPcf = {
34 {0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF},
35 PCF7931_DEFAULT_INITDELAY,
36 PCF7931_DEFAULT_OFFSET_WIDTH,
37 PCF7931_DEFAULT_OFFSET_POSITION
38 };
39
40 // Resets the configuration settings to default values.
41 int pcf7931_resetConfig(){
42 memset(configPcf.Pwd, 0xFF, sizeof(configPcf.Pwd) );
43 configPcf.InitDelay = PCF7931_DEFAULT_INITDELAY;
44 configPcf.OffsetWidth = PCF7931_DEFAULT_OFFSET_WIDTH;
45 configPcf.OffsetPosition = PCF7931_DEFAULT_OFFSET_POSITION;
46 return 0;
47 }
48
49 int pcf7931_printConfig(){
50 PrintAndLog("Password (LSB first on bytes) : %s", sprint_hex( configPcf.Pwd, sizeof(configPcf.Pwd)));
51 PrintAndLog("Tag initialization delay : %d us", configPcf.InitDelay);
52 PrintAndLog("Offset low pulses width : %d us", configPcf.OffsetWidth);
53 PrintAndLog("Offset low pulses position : %d us", configPcf.OffsetPosition);
54 return 0;
55 }
56
57 int usage_pcf7931_read(){
58 PrintAndLog("Usage: lf pcf7931 read [h] ");
59 PrintAndLog("This command tries to read a PCF7931 tag.");
60 PrintAndLog("Options:");
61 PrintAndLog(" h This help");
62 PrintAndLog("Examples:");
63 PrintAndLog(" lf pcf7931 read");
64 return 0;
65 }
66
67 int usage_pcf7931_write(){
68 PrintAndLog("Usage: lf pcf7931 write [h] <block address> <byte address> <data>");
69 PrintAndLog("This command tries to write a PCF7931 tag.");
70 PrintAndLog("Options:");
71 PrintAndLog(" h This help");
72 PrintAndLog(" blockaddress Block to save [0-7]");
73 PrintAndLog(" byteaddress Index of byte inside block to write [0-15]");
74 PrintAndLog(" data one byte of data (hex)");
75 PrintAndLog("Examples:");
76 PrintAndLog(" lf pcf7931 write 2 1 FF");
77 return 0;
78 }
79
80 int usage_pcf7931_bruteforce()
81 {
82 PrintAndLog("Usage: lf pcf7931 bruteforce [h] <start password> <tries>");
83 PrintAndLog("This command tries to disable PAC of a PCF7931 transponder by bruteforcing the password.");
84 PrintAndLog("!! THIS IS NOT INTENDED TO RECOVER THE FULL PASSWORD !!");
85 PrintAndLog("!! DO NOT USE UNLESS THE FIRST 5 BYTES OF THE PASSWORD ARE KNOWN !!");
86 PrintAndLog("Options:");
87 PrintAndLog(" h This help");
88 PrintAndLog(" start password hex password to start from");
89 PrintAndLog(" tries How many times to send the same data frame");
90 PrintAndLog("Examples:");
91 PrintAndLog(" lf pcf7931 bruteforce 00000000123456 3");
92 return 0;
93 }
94
95 int usage_pcf7931_config(){
96 PrintAndLog("Usage: lf pcf7931 config [h] [r] <pwd> <delay> <offset width> <offset position>");
97 PrintAndLog("This command tries to set the configuration used with PCF7931 commands");
98 PrintAndLog("The time offsets could be useful to correct slew rate generated by the antenna");
99 PrintAndLog("Caling without some parameter will print the current configuration.");
100 PrintAndLog("Options:");
101 PrintAndLog(" h This help");
102 PrintAndLog(" r Reset configuration to default values");
103 PrintAndLog(" pwd Password, hex, 7bytes, LSB-order");
104 PrintAndLog(" delay Tag initialization delay (in us) decimal");
105 PrintAndLog(" offset Low pulses width (in us) decimal");
106 PrintAndLog(" offset Low pulses position (in us) decimal");
107 PrintAndLog("Examples:");
108 PrintAndLog(" lf pcf7931 config");
109 PrintAndLog(" lf pcf7931 config r");
110 PrintAndLog(" lf pcf7931 config 11223344556677 20000");
111 PrintAndLog(" lf pcf7931 config 11223344556677 17500 -10 30");
112 return 0;
113 }
114
115 int CmdLFPCF7931Read(const char *Cmd){
116
117 uint8_t ctmp = param_getchar(Cmd, 0);
118 if ( ctmp == 'H' || ctmp == 'h' ) return usage_pcf7931_read();
119
120 UsbCommand resp;
121 UsbCommand c = {CMD_PCF7931_READ, {0, 0, 0}};
122 clearCommandBuffer();
123 SendCommand(&c);
124 if ( !WaitForResponseTimeout(CMD_ACK, &resp, 2500) ) {
125 PrintAndLog("command execution time out");
126 return 1;
127 }
128 return 0;
129 }
130
131 int CmdLFPCF7931Config(const char *Cmd){
132
133 uint8_t ctmp = param_getchar(Cmd, 0);
134 if ( ctmp == 0) return pcf7931_printConfig();
135 if ( ctmp == 'H' || ctmp == 'h' ) return usage_pcf7931_config();
136 if ( ctmp == 'R' || ctmp == 'r' ) return pcf7931_resetConfig();
137
138 if ( param_gethex(Cmd, 0, configPcf.Pwd, 14) ) return usage_pcf7931_config();
139
140 configPcf.InitDelay = (param_get32ex(Cmd,1,0,10) & 0xFFFF);
141 configPcf.OffsetWidth = (int)(param_get32ex(Cmd,2,0,10) & 0xFFFF);
142 configPcf.OffsetPosition = (int)(param_get32ex(Cmd,3,0,10) & 0xFFFF);
143
144 pcf7931_printConfig();
145 return 0;
146 }
147
148 int CmdLFPCF7931Write(const char *Cmd){
149
150 uint8_t ctmp = param_getchar(Cmd, 0);
151 if (strlen(Cmd) < 1 || ctmp == 'h' || ctmp == 'H') return usage_pcf7931_write();
152
153 uint8_t block = 0, bytepos = 0, data = 0;
154
155 if ( param_getdec(Cmd, 0, &block) ) return usage_pcf7931_write();
156 if ( param_getdec(Cmd, 1, &bytepos) ) return usage_pcf7931_write();
157
158 if ( (block > 7) || (bytepos > 15) ) return usage_pcf7931_write();
159
160 data = param_get8ex(Cmd, 2, 0, 16);
161
162 PrintAndLog("Writing block: %d", block);
163 PrintAndLog(" pos: %d", bytepos);
164 PrintAndLog(" data: 0x%02X", data);
165
166 UsbCommand c = {CMD_PCF7931_WRITE, { block, bytepos, data} };
167 memcpy(c.d.asDwords, configPcf.Pwd, sizeof(configPcf.Pwd) );
168 c.d.asDwords[7] = (configPcf.OffsetWidth + 128);
169 c.d.asDwords[8] = (configPcf.OffsetPosition + 128);
170 c.d.asDwords[9] = configPcf.InitDelay;
171
172 clearCommandBuffer();
173 SendCommand(&c);
174 //no ack?
175 return 0;
176 }
177
178 int CmdLFPCF7931BruteForce(const char *Cmd){
179
180 uint8_t ctmp = param_getchar(Cmd, 0);
181 if (strlen(Cmd) < 1 || ctmp == 'h' || ctmp == 'H') return usage_pcf7931_bruteforce();
182
183 uint64_t start_password = 0;
184 uint8_t tries = 3;
185
186 if (param_gethex(Cmd, 0, (uint8_t*)(&start_password), 14)) return usage_pcf7931_bruteforce();
187 if (param_getdec(Cmd, 1, &tries)) return usage_pcf7931_bruteforce();
188
189 PrintAndLog("Bruteforcing from password: %02x %02x %02x %02x %02x %02x %02x",
190 start_password & 0xFF,
191 (start_password >> 8) & 0xFF,
192 (start_password >> 16) & 0xFF,
193 (start_password >> 24) & 0xFF,
194 (start_password >> 32) & 0xFF,
195 (start_password >> 48) & 0xFF,
196 (start_password >> 56) & 0xFF);
197
198 PrintAndLog("Trying each password %d times", tries);
199
200 UsbCommand c = {CMD_PCF7931_BRUTEFORCE, {start_password, tries} };
201
202 c.d.asDwords[7] = (configPcf.OffsetWidth + 128);
203 c.d.asDwords[8] = (configPcf.OffsetPosition + 128);
204 c.d.asDwords[9] = configPcf.InitDelay;
205
206 clearCommandBuffer();
207 SendCommand(&c);
208 //no ack?
209 return 0;
210 }
211
212 static command_t CommandTable[] =
213 {
214 {"help", CmdHelp, 1, "This help"},
215 {"read", CmdLFPCF7931Read, 0, "Read content of a PCF7931 transponder"},
216 {"write", CmdLFPCF7931Write, 0, "Write data on a PCF7931 transponder."},
217 {"config", CmdLFPCF7931Config, 1, "Configure the password, the tags initialization delay and time offsets (optional)"},
218 {"bruteforce", CmdLFPCF7931BruteForce, 0, "Bruteforce a PCF7931 transponder password."},
219 {NULL, NULL, 0, NULL}
220 };
221
222 int CmdLFPCF7931(const char *Cmd)
223 {
224 CmdsParse(CommandTable, Cmd);
225 return 0;
226 }
227
228 int CmdHelp(const char *Cmd)
229 {
230 CmdsHelp(CommandTable);
231 return 0;
232 }
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