+
+/*
+ * 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) {
+ // Index for the bytearray.
+ int i = 0;
+ int k = 0, segmentNum;
+ int segment_len = 0;
+ int segment_flag = 0;
+ uint8_t stamp_len = 0;
+ int crc = 0;
+ int wrp = 0;
+ int wrc = 0;
+ uint8_t data_buf[1024]; // receiver buffer, should be 1024..
+ char token_type[4];
+
+ // download EML memory, where the "legic read" command puts the data.
+ GetEMLFromBigBuf(data_buf, sizeof(data_buf), 0);
+ if ( !WaitForResponseTimeout(CMD_ACK, NULL, 2000)){
+ PrintAndLog("Command execute timeout");
+ return 1;
+ }
+
+ // Output CDF System area (9 bytes) plus remaining header area (12 bytes)
+ crc = data_buf[4];
+ uint32_t calc_crc = CRC8Legic(data_buf, 4);
+
+ PrintAndLog("\nCDF: System Area");
+ PrintAndLog("------------------------------------------------------");
+ PrintAndLog("MCD: %02x, MSN: %02x %02x %02x, MCC: %02x %s",
+ data_buf[0],
+ data_buf[1],
+ data_buf[2],
+ data_buf[3],
+ data_buf[4],
+ (calc_crc == crc) ? "OK":"Fail"
+ );
+
+ switch (data_buf[5] & 0x7f) {
+ case 0x00 ... 0x2f:
+ strncpy(token_type, "IAM",sizeof(token_type));
+ break;
+ case 0x30 ... 0x6f:
+ strncpy(token_type, "SAM",sizeof(token_type));
+ break;
+ case 0x70 ... 0x7f:
+ strncpy(token_type, "GAM",sizeof(token_type));
+ break;
+ default:
+ strncpy(token_type, "???",sizeof(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("%s", sprint_hex(data_buf+9, 13));
+
+ uint8_t segCrcBytes[8] = {0x00};
+ uint32_t segCalcCRC = 0;
+ uint32_t segCRC = 0;
+
+ // see if user area is xored or just zeros.
+ int numOfZeros = 0;
+ for (int index=22; index < 256; ++index){
+ if ( data_buf[index] == 0x00 )
+ ++numOfZeros;
+ }
+ // if possible zeros is less then 60%, lets assume data is xored
+ // 256 - 22 (header) = 234
+ // 1024 - 22 (header) = 1002
+ int isXored = (numOfZeros*100/stamp_len) < 50;
+ PrintAndLog("is data xored? %d ( %d %)", isXored, (numOfZeros*100/stamp_len));
+
+ print_hex_break( data_buf, 33, 16);
+
+ return 0;
+
+ PrintAndLog("\nADF: User Area");
+ PrintAndLog("------------------------------------------------------");
+ i = 22;
+ // 64 potential segements
+ // how to detect there is no segments?!?
+ for ( segmentNum=0; segmentNum<64; segmentNum++ ) {
+ 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;
+
+ bool hasWRC = (wrc > 0);
+ bool hasWRP = (wrp > wrc);
+ int wrp_len = (wrp - wrc);
+ int remain_seg_payload_len = (segment_len - wrp - 5);
+
+ // validate segment-crc
+ segCrcBytes[0]=data_buf[0]; //uid0
+ segCrcBytes[1]=data_buf[1]; //uid1
+ segCrcBytes[2]=data_buf[2]; //uid2
+ segCrcBytes[3]=data_buf[3]; //uid3
+ segCrcBytes[4]=(data_buf[i]^crc); //hdr0
+ segCrcBytes[5]=(data_buf[i+1]^crc); //hdr1
+ segCrcBytes[6]=(data_buf[i+2]^crc); //hdr2
+ segCrcBytes[7]=(data_buf[i+3]^crc); //hdr3
+
+ segCalcCRC = CRC8Legic(segCrcBytes, 8);
+ segCRC = data_buf[i+4]^crc;
+
+ PrintAndLog("Segment %02u \nraw header | 0x%02X 0x%02X 0x%02X 0x%02X \nSegment len: %u, Flag: 0x%X (valid:%01u, last:%01u), WRP: %02u, WRC: %02u, RD: %01u, CRC: 0x%02X (%s)",
+ segmentNum,
+ data_buf[i]^crc,
+ data_buf[i+1]^crc,
+ data_buf[i+2]^crc,
+ data_buf[i+3]^crc,
+ segment_len,
+ segment_flag,
+ (segment_flag & 0x4) >> 2,
+ (segment_flag & 0x8) >> 3,
+ wrp,
+ wrc,
+ ((data_buf[i+3]^crc) & 0x80) >> 7,
+ segCRC,
+ ( segCRC == segCalcCRC ) ? "OK" : "fail"
+ );
+
+ i += 5;
+
+ if ( hasWRC ) {
+ PrintAndLog("WRC protected area: (I %d | K %d| WRC %d)", i, k, wrc);
+ PrintAndLog("\nrow | data");
+ PrintAndLog("-----+------------------------------------------------");
+ // de-xor? if not zero, assume it needs xoring.
+ if ( isXored) {
+ for ( k=i; k < wrc; ++k)
+ data_buf[k] ^= crc;
+ }
+ print_hex_break( data_buf+i, wrc, 16);
+
+ i += wrc;
+ }
+
+ if ( hasWRP ) {
+ PrintAndLog("Remaining write protected area: (I %d | K %d | WRC %d | WRP %d WRP_LEN %d)",i, k, wrc, wrp, wrp_len);
+ PrintAndLog("\nrow | data");
+ PrintAndLog("-----+------------------------------------------------");
+
+ if (isXored) {
+ for (k=i; k < wrp_len; ++k)
+ data_buf[k] ^= crc;
+ }
+
+ print_hex_break( data_buf+i, wrp_len, 16);
+
+ i += wrp_len;
+
+ // does this one work?
+ if( wrp_len == 8 )
+ PrintAndLog("Card ID: %2X%02X%02X", data_buf[i-4]^crc, data_buf[i-3]^crc, data_buf[i-2]^crc);
+ }
+
+ PrintAndLog("Remaining segment payload: (I %d | K %d | Remain LEN %d)", i, k, remain_seg_payload_len);
+ PrintAndLog("\nrow | data");
+ PrintAndLog("-----+------------------------------------------------");
+ if ( isXored ) {
+ for ( k=i; k < remain_seg_payload_len; ++k)
+ data_buf[k] ^= crc;
+ }
+
+ print_hex_break( data_buf+i, remain_seg_payload_len, 16);
+
+ i += remain_seg_payload_len;
+
+ PrintAndLog("-----+------------------------------------------------\n");
+
+ // end with last segment
+ if (segment_flag & 0x8) return 0;
+
+ } // end for loop
+ return 0;
+}
+
+int CmdLegicRFRead(const char *Cmd) {
+
+ // params:
+ // offset in data
+ // number of bytes.
+ char cmdp = param_getchar(Cmd, 0);
+ if ( cmdp == 'H' || cmdp == 'h' ) return usage_legic_read();
+
+ 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}};
+ clearCommandBuffer();
+ SendCommand(&c);
+ return 0;
+}
+
+int CmdLegicLoad(const char *Cmd) {
+
+ char cmdp = param_getchar(Cmd, 0);
+ if ( cmdp == 'H' || cmdp == 'h' || cmdp == 0x00) return usage_legic_load();
+
+ char filename[FILE_PATH_SIZE] = {0x00};
+ int 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;
+ uint8_t data[USB_CMD_DATA_SIZE] = {0x00};
+ int index = 0;
+ int totalbytes = 0;
+ while ( fgets(line, sizeof(line), f) ) {
+ int res = sscanf(line, "%x %x %x %x %x %x %x %x",
+ (unsigned int *)&data[index],
+ (unsigned int *)&data[index + 1],
+ (unsigned int *)&data[index + 2],
+ (unsigned int *)&data[index + 3],
+ (unsigned int *)&data[index + 4],
+ (unsigned int *)&data[index + 5],
+ (unsigned int *)&data[index + 6],
+ (unsigned int *)&data[index + 7]);
+
+ if(res != 8) {
+ PrintAndLog("Error: could not read samples");
+ fclose(f);
+ return -1;
+ }
+ index += res;
+
+ if ( index == USB_CMD_DATA_SIZE ){
+// PrintAndLog("sent %d | %d | %d", index, offset, totalbytes);
+ UsbCommand c = { CMD_DOWNLOADED_SIM_SAMPLES_125K, {offset, 0, 0}};
+ memcpy(c.d.asBytes, data, sizeof(data));
+ clearCommandBuffer();
+ SendCommand(&c);
+ if ( !WaitForResponseTimeout(CMD_ACK, NULL, 1500)){
+ PrintAndLog("Command execute timeout");
+ fclose(f);
+ return 1;
+ }
+ offset += index;
+ totalbytes += index;
+ index = 0;
+ }
+ }
+ fclose(f);
+
+ // left over bytes?
+ if ( index != 0 ) {
+ UsbCommand c = { CMD_DOWNLOADED_SIM_SAMPLES_125K, {offset, 0, 0}};
+ memcpy(c.d.asBytes, data, 8);
+ clearCommandBuffer();
+ SendCommand(&c);
+ if ( !WaitForResponseTimeout(CMD_ACK, NULL, 1500)){
+ PrintAndLog("Command execute timeout");
+ return 1;
+ }
+ totalbytes += index;
+ }
+
+ PrintAndLog("loaded %u samples", totalbytes);
+ 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] = {0x00};
+
+ 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;
+ }
+
+ GetFromBigBuf(got, requested, offset);
+ if ( !WaitForResponseTimeout(CMD_ACK, NULL, 2000)){
+ PrintAndLog("Command execute timeout");
+ return 1;
+ }
+
+ FILE *f = fopen(filename, "w");
+ if(!f) {
+ PrintAndLog("couldn't open '%s'", Cmd+1);
+ return -1;
+ }
+
+ 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;
+}
+
+//TODO: write a help text (iceman)
+int CmdLegicRfSim(const char *Cmd) {
+ UsbCommand c = {CMD_SIMULATE_TAG_LEGIC_RF, {6,3,0}};
+ sscanf(Cmd, " %"lli" %"lli" %"lli, &c.arg[0], &c.arg[1], &c.arg[2]);
+ clearCommandBuffer();
+ SendCommand(&c);
+ return 0;
+}
+
+//TODO: write a help text (iceman)
+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;
+ }
+ clearCommandBuffer();
+ 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);
+ }
+ clearCommandBuffer();
+ SendCommand(&cmd);
+ return 0;
+ }
+
+int CmdLegicCalcCrc8(const char *Cmd){
+
+ int len = strlen(Cmd);
+ if ( len & 1 ) return usage_legic_calccrc8();
+
+ // add 1 for null terminator.
+ uint8_t *data = malloc(len+1);
+ if ( data == NULL ) return 1;
+
+ if (param_gethex(Cmd, 0, data, len )) {
+ free(data);
+ return usage_legic_calccrc8();
+ }
+
+ uint32_t checksum = CRC8Legic(data, len/2);
+ PrintAndLog("Bytes: %s || CRC8: %X", sprint_hex(data, len/2), checksum );
+ free(data);
+ return 0;
+}
+
+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)"},
+ {"read", 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"},
+ {"crc8", CmdLegicCalcCrc8, 1, "Calculate Legic CRC8 over given hexbytes"},
+ {NULL, NULL, 0, NULL}
+};
+
+int CmdHFLegic(const char *Cmd) {
+ clearCommandBuffer();
+ CmdsParse(CommandTable, Cmd);
+ return 0;
+}
+
+int CmdHelp(const char *Cmd) {
+ CmdsHelp(CommandTable);
+ return 0;
+}
\ No newline at end of file
projects / proxmark3-svn / blobdiff