proxmark3/client/cmdhflegic.c
marshmellow42 568377946c FIX: Coverity, Out-of-bounds. In the loop, variable i, can...
...be as much as 1051, overflowing the databuf with size 1024.
2016-02-14 12:36:55 -05:00

366 lines
9.5 KiB
C

//-----------------------------------------------------------------------------
// Copyright (C) 2010 iZsh <izsh at fail0verflow.com>
//
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// High frequency Legic commands
//-----------------------------------------------------------------------------
#include <stdio.h>
#include <string.h>
#include "proxmark3.h"
#include "data.h"
#include "ui.h"
#include "cmdparser.h"
#include "cmdhflegic.h"
#include "cmdmain.h"
#include "util.h"
static int CmdHelp(const char *Cmd);
static command_t CommandTable[] =
{
{"help", CmdHelp, 1, "This help"},
{"decode", CmdLegicDecode, 0, "Display deobfuscated and decoded LEGIC RF tag data (use after hf legic reader)"},
{"reader", CmdLegicRFRead, 0, "[offset [length]] -- read bytes from a LEGIC card"},
{"save", CmdLegicSave, 0, "<filename> [<length>] -- Store samples"},
{"load", CmdLegicLoad, 0, "<filename> -- Restore samples"},
{"sim", CmdLegicRfSim, 0, "[phase drift [frame drift [req/resp drift]]] Start tag simulator (use after load or read)"},
{"write", CmdLegicRfWrite,0, "<offset> <length> -- Write sample buffer (user after load or read)"},
{"fill", CmdLegicRfFill, 0, "<offset> <length> <value> -- Fill/Write tag with constant value"},
{NULL, NULL, 0, NULL}
};
int CmdHFLegic(const char *Cmd)
{
CmdsParse(CommandTable, Cmd);
return 0;
}
int CmdHelp(const char *Cmd)
{
CmdsHelp(CommandTable);
return 0;
}
/*
* Output BigBuf and deobfuscate LEGIC RF tag data.
* This is based on information given in the talk held
* by Henryk Ploetz and Karsten Nohl at 26c3
*/
int CmdLegicDecode(const char *Cmd)
{
int i, j, k, n;
int segment_len = 0;
int segment_flag = 0;
int stamp_len = 0;
int crc = 0;
int wrp = 0;
int wrc = 0;
uint8_t data_buf[1052]; // receiver buffer
char out_string[3076]; // just use big buffer - bad practice
char token_type[4];
// copy data from proxmark into buffer
GetFromBigBuf(data_buf,sizeof(data_buf),0);
WaitForResponse(CMD_ACK,NULL);
// Output CDF System area (9 bytes) plus remaining header area (12 bytes)
PrintAndLog("\nCDF: System Area");
PrintAndLog("MCD: %02x, MSN: %02x %02x %02x, MCC: %02x",
data_buf[0],
data_buf[1],
data_buf[2],
data_buf[3],
data_buf[4]
);
crc = data_buf[4];
switch (data_buf[5]&0x7f) {
case 0x00 ... 0x2f:
strncpy(token_type, "IAM",sizeof(token_type));
break;
case 0x30 ... 0x6f:
strcpy(token_type, "SAM");
break;
case 0x70 ... 0x7f:
strcpy(token_type, "GAM");
break;
default:
strcpy(token_type, "???");
break;
}
stamp_len = 0xfc - data_buf[6];
PrintAndLog("DCF: %02x %02x, Token_Type=%s (OLE=%01u), Stamp_len=%02u",
data_buf[5],
data_buf[6],
token_type,
(data_buf[5]&0x80)>>7,
stamp_len
);
PrintAndLog("WRP=%02u, WRC=%01u, RD=%01u, raw=%02x, SSC=%02x",
data_buf[7]&0x0f,
(data_buf[7]&0x70)>>4,
(data_buf[7]&0x80)>>7,
data_buf[7],
data_buf[8]
);
PrintAndLog("Remaining Header Area");
PrintAndLog("%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
data_buf[9],
data_buf[10],
data_buf[11],
data_buf[12],
data_buf[13],
data_buf[14],
data_buf[15],
data_buf[16],
data_buf[17],
data_buf[18],
data_buf[19],
data_buf[20],
data_buf[21]
);
PrintAndLog("\nADF: User Area");
i = 22;
for (n=0; n<64; n++) {
segment_len = ((data_buf[i+1]^crc)&0x0f) * 256 + (data_buf[i]^crc);
segment_flag = ((data_buf[i+1]^crc)&0xf0)>>4;
wrp = (data_buf[i+2]^crc);
wrc = ((data_buf[i+3]^crc)&0x70)>>4;
PrintAndLog("Segment %02u: raw header=%02x %02x %02x %02x, flag=%01x (valid=%01u, last=%01u), len=%04u, WRP=%02u, WRC=%02u, RD=%01u, CRC=%02x",
n,
data_buf[i]^crc,
data_buf[i+1]^crc,
data_buf[i+2]^crc,
data_buf[i+3]^crc,
segment_flag,
(segment_flag&0x4)>>2,
(segment_flag&0x8)>>3,
segment_len,
wrp,
wrc,
((data_buf[i+3]^crc)&0x80)>>7,
(data_buf[i+4]^crc)
);
i+=5;
if (wrc>0) {
PrintAndLog("WRC protected area:");
for (k=0, j=0; k < wrc && j<(sizeof(out_string)-3); k++, i++, j += 3) {
sprintf(&out_string[j], "%02x", (data_buf[i]^crc));
out_string[j+2] = ' ';
};
out_string[j] = '\0';
PrintAndLog("%s", out_string);
}
if (wrp>wrc) {
PrintAndLog("Remaining write protected area:");
for (k=0, j=0; k < (wrp-wrc) && j<(sizeof(out_string)-3); k++, i++, j += 3) {
sprintf(&out_string[j], "%02x", (data_buf[i]^crc));
out_string[j+2] = ' ';
};
out_string[j] = '\0';
PrintAndLog("%s", out_string);
if((wrp-wrc) == 8) {
sprintf(out_string,"Card ID: %2X%02X%02X",data_buf[i-4]^crc,data_buf[i-3]^crc,data_buf[i-2]^crc);
PrintAndLog("%s", out_string);
}
}
PrintAndLog("Remaining segment payload:");
for (k=0, j=0; k < (segment_len - wrp - 5) && j<(sizeof(out_string)-3); k++, i++, j += 3) {
sprintf(&out_string[j], "%02x", (data_buf[i]^crc));
out_string[j+2] = ' ';
};
out_string[j] = '\0';
PrintAndLog("%s", out_string);
// end with last segment
if (segment_flag & 0x8)
return 0;
};
return 0;
}
int CmdLegicRFRead(const char *Cmd)
{
int byte_count=0,offset=0;
sscanf(Cmd, "%i %i", &offset, &byte_count);
if(byte_count == 0) byte_count = -1;
if(byte_count + offset > 1024) byte_count = 1024 - offset;
UsbCommand c={CMD_READER_LEGIC_RF, {offset, byte_count, 0}};
SendCommand(&c);
return 0;
}
int CmdLegicLoad(const char *Cmd)
{
char filename[FILE_PATH_SIZE] = {0x00};
int len = 0;
if (param_getchar(Cmd, 0) == 'h' || param_getchar(Cmd, 0)== 0x00) {
PrintAndLog("It loads datasamples from the file `filename`");
PrintAndLog("Usage: hf legic load <file name>");
PrintAndLog(" sample: hf legic load filename");
return 0;
}
len = strlen(Cmd);
if (len > FILE_PATH_SIZE) {
PrintAndLog("Filepath too long (was %s bytes), max allowed is %s ", len, FILE_PATH_SIZE);
return 0;
}
memcpy(filename, Cmd, len);
FILE *f = fopen(filename, "r");
if(!f) {
PrintAndLog("couldn't open '%s'", Cmd);
return -1;
}
char line[80]; int offset = 0; unsigned int data[8];
while(fgets(line, sizeof(line), f)) {
int res = sscanf(line, "%x %x %x %x %x %x %x %x",
&data[0], &data[1], &data[2], &data[3],
&data[4], &data[5], &data[6], &data[7]);
if(res != 8) {
PrintAndLog("Error: could not read samples");
fclose(f);
return -1;
}
UsbCommand c={CMD_DOWNLOADED_SIM_SAMPLES_125K, {offset, 0, 0}};
int j; for(j = 0; j < 8; j++) {
c.d.asBytes[j] = data[j];
}
SendCommand(&c);
WaitForResponse(CMD_ACK, NULL);
offset += 8;
}
fclose(f);
PrintAndLog("loaded %u samples", offset);
return 0;
}
int CmdLegicSave(const char *Cmd)
{
int requested = 1024;
int offset = 0;
int delivered = 0;
char filename[FILE_PATH_SIZE];
uint8_t got[1024];
sscanf(Cmd, " %s %i %i", filename, &requested, &offset);
/* If no length given save entire legic read buffer */
/* round up to nearest 8 bytes so the saved data can be used with legicload */
if (requested == 0) {
requested = 1024;
}
if (requested % 8 != 0) {
int remainder = requested % 8;
requested = requested + 8 - remainder;
}
if (offset + requested > sizeof(got)) {
PrintAndLog("Tried to read past end of buffer, <bytes> + <offset> > 1024");
return 0;
}
FILE *f = fopen(filename, "w");
if(!f) {
PrintAndLog("couldn't open '%s'", Cmd+1);
return -1;
}
GetFromBigBuf(got,requested,offset);
WaitForResponse(CMD_ACK,NULL);
for (int j = 0; j < requested; j += 8) {
fprintf(f, "%02x %02x %02x %02x %02x %02x %02x %02x\n",
got[j+0],
got[j+1],
got[j+2],
got[j+3],
got[j+4],
got[j+5],
got[j+6],
got[j+7]
);
delivered += 8;
if (delivered >= requested)
break;
}
fclose(f);
PrintAndLog("saved %u samples", delivered);
return 0;
}
int CmdLegicRfSim(const char *Cmd)
{
UsbCommand c={CMD_SIMULATE_TAG_LEGIC_RF};
c.arg[0] = 6;
c.arg[1] = 3;
c.arg[2] = 0;
sscanf(Cmd, " %"lli" %"lli" %"lli, &c.arg[0], &c.arg[1], &c.arg[2]);
SendCommand(&c);
return 0;
}
int CmdLegicRfWrite(const char *Cmd)
{
UsbCommand c={CMD_WRITER_LEGIC_RF};
int res = sscanf(Cmd, " 0x%"llx" 0x%"llx, &c.arg[0], &c.arg[1]);
if(res != 2) {
PrintAndLog("Please specify the offset and length as two hex strings");
return -1;
}
SendCommand(&c);
return 0;
}
int CmdLegicRfFill(const char *Cmd)
{
UsbCommand cmd ={CMD_WRITER_LEGIC_RF};
int res = sscanf(Cmd, " 0x%"llx" 0x%"llx" 0x%"llx, &cmd.arg[0], &cmd.arg[1], &cmd.arg[2]);
if(res != 3) {
PrintAndLog("Please specify the offset, length and value as two hex strings");
return -1;
}
int i;
UsbCommand c={CMD_DOWNLOADED_SIM_SAMPLES_125K, {0, 0, 0}};
for(i = 0; i < 48; i++) {
c.d.asBytes[i] = cmd.arg[2];
}
for(i = 0; i < 22; i++) {
c.arg[0] = i*48;
SendCommand(&c);
WaitForResponse(CMD_ACK,NULL);
}
SendCommand(&cmd);
return 0;
}