Update README.md

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index 880e2c2b04ebfe20cd6d212f82d20837db9e5eb4..7690004707881cd230f566afeed40aa7d49abe6c 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -10,8 +10,8 @@
 //
 // NOTES: 
 // LF Demod functions are placed here to allow the flexability to use client or
-// device side. Most BUT NOT ALL of these functions are currenlty safe for 
-// device side use currently. (DetectST for example...)
+// device side. Most BUT NOT ALL of these functions are currently safe for 
+// device side use. (DetectST for example...)
 //
 // There are likely many improvements to the code that could be made, please
 // make suggestions...
@@ -1777,22 +1777,53 @@ int IOdemodFSK(uint8_t *dest, size_t size, int *waveStartIdx) {
 } 
 
 // redesigned by marshmellow adjusted from existing decode functions
-// indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
-int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert) {
-       //26 bit 40134 format  (don't know other formats)
-       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
-       uint8_t preamble_i[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0};
-       size_t startidx = 0; 
-       if (!preambleSearch(bitStream, preamble, sizeof(preamble), size, &startidx)){
-               // if didn't find preamble try again inverting
-               if (!preambleSearch(bitStream, preamble_i, sizeof(preamble_i), size, &startidx)) return -1;
+// indala id decoding
+int indala64decode(uint8_t *bitStream, size_t *size, uint8_t *invert) {
+       //standard 64 bit indala formats including 26 bit 40134 format
+       uint8_t preamble64[] = {1,0,1,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 1};
+       uint8_t preamble64_i[] = {0,1,0,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 0};
+       size_t startidx = 0;
+       size_t found_size = *size;
+       bool found = preambleSearch(bitStream, preamble64, sizeof(preamble64), &found_size, &startidx);
+       if (!found) {
+               found = preambleSearch(bitStream, preamble64_i, sizeof(preamble64_i), &found_size, &startidx);
+               if (!found) return -1;
                *invert ^= 1;
-       } 
-       if (*size != 64 && *size != 224) return -2;
+       }
+       if (found_size != 64) return -2;
        if (*invert==1)
-               for (size_t i = startidx; i < *size + startidx; i++) 
+               for (size_t i = startidx; i < found_size + startidx; i++) 
+                       bitStream[i] ^= 1;
+
+       // note: don't change *size until we are sure we got it... 
+       *size = found_size;
+       return (int) startidx;
+}
+
+int indala224decode(uint8_t *bitStream, size_t *size, uint8_t *invert) {
+       //large 224 bit indala formats (different preamble too...)
+       uint8_t preamble224[] = {1,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,1};
+       uint8_t preamble224_i[] = {0,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,0};
+       size_t startidx = 0;
+       size_t found_size = *size;
+       bool found = preambleSearch(bitStream, preamble224, sizeof(preamble224), &found_size, &startidx);
+       if (!found) {
+               found = preambleSearch(bitStream, preamble224_i, sizeof(preamble224_i), &found_size, &startidx);
+               if (!found) return -1;
+               *invert ^= 1;
+       }
+       if (found_size != 224) return -2;
+       if (*invert==1 && startidx > 0)
+               for (size_t i = startidx-1; i < found_size + startidx + 2; i++) 
                        bitStream[i] ^= 1;
 
+       // 224 formats are typically PSK2 (afaik 2017 Marshmellow)
+       // note loses 1 bit at beginning of transformation...
+       // don't need to verify array is big enough as to get here there has to be a full preamble after all of our data
+       psk1TOpsk2(bitStream + (startidx-1), found_size+2);
+       startidx++;
+
+       *size = found_size;
        return (int) startidx;
 }