FIX: @Aczid suggested this to fix a Coverity scan warning.

[proxmark3-svn] / client / cmdhflegic.c

diff --git a/client/cmdhflegic.c b/client/cmdhflegic.c
index 7ee601b232888aaece3aa1fe70b42d1731879d85..0262f81c5560a7e1160b9dde859d7fb9f8d26e04 100644 (file)
--- a/client/cmdhflegic.c
+++ b/client/cmdhflegic.c
@@ -17,218 +17,264 @@
 #include "cmdhflegic.h"
 #include "cmdmain.h"
 #include "util.h"
 #include "cmdhflegic.h"
 #include "cmdmain.h"
 #include "util.h"

+#include "crc.h"

 static int CmdHelp(const char *Cmd);
 
 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 usage_legic_calccrc8(void){
+       PrintAndLog("Calculates the legic crc8 on the input hexbytes.");
+       PrintAndLog("There must be an even number of hexsymbols as input.");
+       PrintAndLog("Usage:  hf legic crc8 <hexbytes>");
+       PrintAndLog("Options :");
+       PrintAndLog("  <hexbytes>   : hex bytes in a string");
+       PrintAndLog("");
+       PrintAndLog("Sample  : hf legic crc8 deadbeef1122");
+       return 0;
+}

 
 

-int CmdHFLegic(const char *Cmd)
-{
-  CmdsParse(CommandTable, Cmd);
-  return 0;
+int usage_legic_load(void){
+       PrintAndLog("It loads datasamples from the file `filename` to device memory");
+       PrintAndLog("Usage:  hf legic load <file name>");
+       PrintAndLog(" sample: hf legic load filename");
+       return 0;

 }
 
 }
 

-int CmdHelp(const char *Cmd)
-{
-  CmdsHelp(CommandTable);
-  return 0;
+int usage_legic_read(void){    
+       PrintAndLog("Read data from a legic tag.");
+       PrintAndLog("Usage:  hf legic read <offset> <num of bytes>");
+       PrintAndLog("Options :");
+       PrintAndLog("  <offset>        : offset in data array to start download from");
+       PrintAndLog("  <num of bytes>  : number of bytes to download");
+       PrintAndLog("");
+       PrintAndLog(" sample: hf legic read");
+       return 0;

 }
 
 /*
  *  Output BigBuf and deobfuscate LEGIC RF tag data.
 }
 
 /*
  *  Output BigBuf and deobfuscate LEGIC RF tag data.

- *   This is based on information given in the talk held
+ *  This is based on information given in the talk held

  *  by Henryk Ploetz and Karsten Nohl at 26c3
  */
  *  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[1024]; // 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];
+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:
-      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);
-      }
-    }
+       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;

     
     

-    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] = ' ';
-    };
+               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;
+               }

     
     

-    out_string[j] = '\0';
+               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("%s", out_string);
+               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);

     
     

-    // end with last segment
-    if (segment_flag & 0x8)
-      return 0;
-  };
-  return 0;
+               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)
-{
-  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 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 filename[FILE_PATH_SIZE] = {0x00};
-       int len = 0;
+int CmdLegicLoad(const char *Cmd) {

        
        

-       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;
-       }
+       char cmdp = param_getchar(Cmd, 0);
+       if ( cmdp == 'H' || cmdp == 'h' || cmdp == 0x00) return usage_legic_load();

 
 

-       len = strlen(Cmd);      
+       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;
        if (len > FILE_PATH_SIZE) {
                PrintAndLog("Filepath too long (was %s bytes), max allowed is %s ", len, FILE_PATH_SIZE);
                return 0;


@@ -240,109 +286,139 @@ int CmdLegicLoad(const char *Cmd)
         PrintAndLog("couldn't open '%s'", Cmd);
         return -1;
     }
         PrintAndLog("couldn't open '%s'", Cmd);
         return -1;
     }

-    char line[80]; int offset = 0; unsigned int data[8];
-    while(fgets(line, sizeof(line), f)) {
+       
+    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", 
         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]);
+            (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;
         }
         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;
+               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);
     }
     fclose(f);

-    PrintAndLog("loaded %u samples", offset);
+       
+       // 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;
 }
 
     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 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;

 }
 
 }
 

-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;
+//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;

 }
 
 }
 

-int CmdLegicRfWrite(const char *Cmd)
-{
-    UsbCommand c={CMD_WRITER_LEGIC_RF};
+//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;
     }
     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;
 }
 
     SendCommand(&c);
     return 0;
 }
 

-int CmdLegicRfFill(const char *Cmd)
-{
-    UsbCommand cmd ={CMD_WRITER_LEGIC_RF};
+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");
     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");


@@ -350,16 +426,61 @@ int CmdLegicRfFill(const char *Cmd)
     }
 
     int i;
     }
 
     int i;

-    UsbCommand c={CMD_DOWNLOADED_SIM_SAMPLES_125K, {0, 0, 0}};
+    UsbCommand c = {CMD_DOWNLOADED_SIM_SAMPLES_125K, {0, 0, 0}};

     for(i = 0; i < 48; i++) {
     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);
+               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;
  }
 
     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