Add new action in nfc-mftool. Its now possible to extract payload (data blocks) from a MFD

Fix minor bug message in nfc-mftool.

src/examples/nfc-mftool.c

@@ -272,39 +272,92 @@ bool write_card()
   return true;
 }
 
-int main(int argc, const char* argv[])
+void mifare_classic_extract_payload(const char* abDump, char* pbPayload)
 {
-  bool b4K;
-  bool bReadAction;
-  byte_t* pbtUID;
-  FILE* pfKeys = NULL;
-  FILE* pfDump = NULL;
+  uint8_t uiSectorIndex;
+  uint8_t uiBlockIndex;
+  size_t szDumpOffset;
+  size_t szPayloadIndex = 0;
 
-  if (argc < 4)
-  {
+  for(uiSectorIndex=1; uiSectorIndex<16; uiSectorIndex++) {
+    for(uiBlockIndex=0; uiBlockIndex<3; uiBlockIndex++) {
+      szDumpOffset = uiSectorIndex*16*4 + uiBlockIndex*16;
+//      for(uint8_t uiByteIndex=0; uiByteIndex<16; uiByteIndex++) printf("%02x ", abDump[szPayloadIndex+uiByteIndex]);
+      memcpy(pbPayload+szPayloadIndex, abDump+szDumpOffset, 16);
+      szPayloadIndex += 16;
+    }
+  }
+}
+
+typedef enum {
+  ACTION_READ,
+  ACTION_WRITE,
+  ACTION_EXPLAIN,
+  ACTION_EXTRACT
+} action_t;
+
+void print_usage(const char* pcProgramName)
+{
   printf("\n");
-    printf("%s r|w a|b <dump.mfd> [<keys.mfd>]\n", argv[0]);
+  printf("%s r|w a|b <dump.mfd> [<keys.mfd>]\n", pcProgramName);
   printf("\n");
   printf("r|w         - Perform read from (r) or write to (w) card\n");
   printf("a|b         - Use A or B keys for action\n");
   printf("<dump.mfd>  - MiFare Dump (MFD) used to write (card to MFD) or (MFD to card)\n");
   printf("<keys.mfd>  - MiFare Dump (MFD) that contain the keys (optional)\n");
   printf("\n");
-    return 1;
-  }
+}
+
+int main(int argc, const char* argv[])
+{
+  bool b4K;
+  action_t atAction;
+  byte_t* pbtUID;
+  FILE* pfKeys = NULL;
+  FILE* pfDump = NULL;
 
   // printf("Checking arguments and settings\n");
 
-  bReadAction = (tolower(*(argv[1])) == 'r');
+  if(argc < 2)
+  {
+    print_usage(argv[0]);
+    return 1;
+  }
+
+  const char* command = argv[1];
+  if(strcmp(command, "r") == 0)
+  {
+    atAction = ACTION_READ;
     bUseKeyA = (tolower(*(argv[2])) == 'a');
     bUseKeyFile = (argc > 4);
+  } else if(strcmp(command, "w") == 0) 
+  {
+    atAction = ACTION_WRITE;
+    bUseKeyA = (tolower(*(argv[2])) == 'a');
+    bUseKeyFile = (argc > 4);
+  } else if(strcmp(command, "e") == 0)
+  {
+    atAction = ACTION_EXPLAIN;
+  } else if(strcmp(command, "x") == 0)
+  {
+    atAction = ACTION_EXTRACT;
+  }
+
+  switch(atAction) {
+    case ACTION_READ:
+    case ACTION_WRITE:
+      if (argc < 4)
+      {
+        print_usage(argv[0]);
+        return 1;
+      }
 
       if (bUseKeyFile)
       {
         pfKeys = fopen(argv[4],"rb");
         if (pfKeys == NULL)
         {
-      printf("Could not open keys file: %s\n",argv[3]);
+          printf("Could not open keys file: %s\n",argv[4]);
           return 1;
         }
         if (fread(&mtKeys,1,sizeof(mtKeys),pfKeys) != sizeof(mtKeys))
@@ -316,8 +369,7 @@ int main(int argc, const char* argv[])
         fclose(pfKeys);
       }
     
-  if (bReadAction)
-  {
+      if(atAction == ACTION_READ) {
         memset(&mtDump,0x00,sizeof(mtDump));
       } else {
         pfDump = fopen(argv[3],"rb");
@@ -397,7 +449,7 @@ int main(int argc, const char* argv[])
     
       uiBlocks = (b4K)?0xff:0x3f;
     
-  if (bReadAction)
+      if (atAction == ACTION_READ)
       {
         if (read_card())
         {
@@ -420,6 +472,47 @@ int main(int argc, const char* argv[])
       }
     
       nfc_disconnect(pdi);
+      break;
+
+    case ACTION_EXTRACT: {
+      const char* pcDump = argv[2];
+      const char* pcPayload = argv[3];
+
+      FILE* pfDump = NULL;
+      FILE* pfPayload = NULL;
+      
+      char abDump[4096];
+      char abPayload[4096];
+
+      pfDump = fopen(pcDump,"rb");
+    
+      if (pfDump == NULL)
+      {
+        printf("Could not open dump file: %s\n",pcDump);
+        return 1;
+      }
+    
+      if (fread(abDump,1,sizeof(abDump),pfDump) != sizeof(abDump))
+      {
+        printf("Could not read dump file: %s\n",pcDump);
+        fclose(pfDump);
+        return 1;
+      }
+      fclose(pfDump);
+
+      mifare_classic_extract_payload(abDump, abPayload);
+
+      printf("Writing data to file: %s\n",pcPayload);
+      pfPayload = fopen(pcPayload,"wb");
+      if (fwrite(abPayload,1,sizeof(abPayload),pfPayload) != sizeof(abPayload))
+      {
+        printf("Could not write to file: %s\n",pcPayload);
+        return 1;
+      }
+      fclose(pfPayload);
+      printf("Done, all bytes have been extracted!\n");
+    }
+  };
 
   return 0;
 }