Added the bitmask + a getlevel() function copied from Daeken's python…

… code

c/decrypt_emotiv.c

@@ -11,8 +11,39 @@
 
 #define KEYSIZE 16 /* 128 bits == 16 bytes */
 
-unsigned char CONSUMERKEY[KEYSIZE] =  {0x31,0x00,0x35,0x54,0x38,0x10,0x37,0x42,0x31,0x00,0x35,0x48,0x38,0x00,0x37,0x50};
-unsigned char RESEARCHKEY[KEYSIZE] =  {0x31,0x00,0x39,0x54,0x38,0x10,0x37,0x42,0x31,0x00,0x39,0x48,0x38,0x00,0x37,0x50};
+const unsigned char CONSUMERKEY[KEYSIZE] =  {0x31,0x00,0x35,0x54,0x38,0x10,0x37,0x42,0x31,0x00,0x35,0x48,0x38,0x00,0x37,0x50};
+const unsigned char RESEARCHKEY[KEYSIZE] =  {0x31,0x00,0x39,0x54,0x38,0x10,0x37,0x42,0x31,0x00,0x39,0x48,0x38,0x00,0x37,0x50};
+
+const unsigned char F3_MASK[14] = {10, 11, 12, 13, 14, 15, 0, 1, 2, 3, 4, 5, 6, 7}; 
+const unsigned char FC6_MASK[14] = {214, 215, 200, 201, 202, 203, 204, 205, 206, 207, 192, 193, 194, 195};
+const unsigned char P7_MASK[14] = {84, 85, 86, 87, 72, 73, 74, 75, 76, 77, 78, 79, 64, 65};
+const unsigned char T8_MASK[14] = {160, 161, 162, 163, 164, 165, 166, 167, 152, 153, 154, 155, 156, 157};
+const unsigned char F7_MASK[14] = {48, 49, 50, 51, 52, 53, 54, 55, 40, 41, 42, 43, 44, 45};
+const unsigned char F8_MASK[14] = {178, 179, 180, 181, 182, 183, 168, 169, 170, 171, 172, 173, 174, 175};
+const unsigned char T7_MASK[14] = {66, 67, 68, 69, 70, 71, 56, 57, 58, 59, 60, 61, 62, 63};
+const unsigned char P8_MASK[14] = {158, 159, 144, 145, 146, 147, 148, 149, 150, 151, 136, 137, 138, 139};
+const unsigned char AF4_MASK[14] = {196, 197, 198, 199, 184, 185, 186, 187, 188, 189, 190, 191, 176, 177};
+const unsigned char F4_MASK[14] = {216, 217, 218, 219, 220, 221, 222, 223, 208, 209, 210, 211, 212, 213};
+const unsigned char AF3_MASK[14] = {46, 47, 32, 33, 34, 35, 36, 37, 38, 39, 24, 25, 26, 27};
+const unsigned char O2_MASK[14] = {140, 141, 142, 143, 128, 129, 130, 131, 132, 133, 134, 135, 120, 121};
+const unsigned char O1_MASK[14] = {102, 103, 88, 89, 90, 91, 92, 93, 94, 95, 80, 81, 82, 83};
+const unsigned char FC5_MASK[14] = {28, 29, 30, 31, 16, 17, 18, 19, 20, 21, 22, 23, 8, 9};
+
+int get_level(unsigned char frame[32], const unsigned char bits[14]) {
+    char i;
+    char b,o;
+    int level = 0;
+
+    for (i= 13; i == -1; --i){
+        level <<= 1;
+        b = (bits[i] / 8) + 1;
+        o = bits[i] % 8;
+
+        level |= (frame[b] >> o) & 1;
+    }
+
+    return level;
+}
 
 int main(int argc, char **argv)
 {
@@ -37,9 +68,20 @@ int main(int argc, char **argv)
   input = fopen(argv[2], "rb");
   if (input == NULL)
   {
-    fputs("File read error", stderr);
+    fputs("File read error: couldn't open the EEG source!", stderr);
     return 1;
   }
+
+  if (argc == 3) {
+      output = stdout;
+  } else {
+      output = fopen(argv[3], "wb");
+      if (input == NULL)
+      {
+        fputs("File write error: couldn't open the destination file for uncrypted data", stderr);
+        return 1;
+      }
+  }
 
   td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, NULL, MCRYPT_ECB, NULL);
   blocksize = mcrypt_enc_get_block_size(td); //should return a 16bits blocksize