ADD: num_to_bytebitsLSBF function.

[proxmark3-svn] / client / util.c

diff --git a/client/util.c b/client/util.c
index 586d930b263d68bebb653d889a75aea281969fba..9768dbeb088bb538a1c3d21408d61f4a823732c7 100644 (file)
--- a/client/util.c
+++ b/client/util.c
@@ -103,6 +103,7 @@ void print_hex(const uint8_t * data, const size_t len) {
                printf("%02x ", data[i]);
        printf("\n");
 }
+
 void print_hex_break(const uint8_t *data, const size_t len, uint8_t breaks) {
 
        int rownum = 0;
@@ -135,8 +136,10 @@ char *sprint_hex(const uint8_t *data, const size_t len) {
 }
 
 char *sprint_bin_break(const uint8_t *data, const size_t len, const uint8_t breaks) {
+       
        // make sure we don't go beyond our char array memory
-       int max_len;
+       size_t in_index = 0, out_index = 0;
+       int max_len;    
        if (breaks==0)
                max_len = ( len > MAX_BIN_BREAK_LENGTH ) ? MAX_BIN_BREAK_LENGTH : len;
        else
@@ -147,20 +150,20 @@ char *sprint_bin_break(const uint8_t *data, const size_t len, const uint8_t brea
        memset(buf, 0x00, sizeof(buf));
        char *tmp = buf;
 
-       size_t in_index = 0;
        // loop through the out_index to make sure we don't go too far
-       for (size_t out_index=0; out_index < max_len-2; out_index++) {
+       for (out_index=0; out_index < max_len-2; out_index++) {
                // set character
-               sprintf(tmp++, "%u", data[in_index]);
+               sprintf(tmp++, "%u", (unsigned int) data[in_index]);
                // check if a line break is needed and we have room to print it in our array
                if ( (breaks > 0) && !((in_index+1) % breaks) && (out_index+1 != max_len) ) {
                        // increment and print line break
                        out_index++;
                        sprintf(tmp++, "%s","\n");
-       }
+               }
                in_index++;
        }
-
+       // last char.
+       sprintf(tmp++, "%u", (unsigned int) data[in_index]);
        return buf;
 }
 
@@ -176,6 +179,7 @@ char *sprint_hex_ascii(const uint8_t *data, const size_t len) {
        sprintf(tmp, "%s| %s", sprint_hex(data, max_len) , data);       
        return buf;
 }
+
 void num_to_bytes(uint64_t n, size_t len, uint8_t* dest)
 {
        while (len--) {
@@ -195,12 +199,22 @@ uint64_t bytes_to_num(uint8_t* src, size_t len)
        return num;
 }
 
-void num_to_bytebits(uint64_t  n, size_t len, uint8_t *dest) {
+// takes a number (uint64_t) and creates a binarray in dest.
+void num_to_bytebits(uint64_t n, size_t len, uint8_t *dest) {
        while (len--) {
                dest[len] = n & 1;
                n >>= 1;
        }
 }
+//least significant bit first
+void num_to_bytebitsLSBF(uint64_t n, size_t len, uint8_t *dest)
+{
+       for(int i = 0 ; i < len ; ++i) {
+               dest[i] =  n & 1;
+               n >>= 1;
+       }
+}
+
 
 // aa,bb,cc,dd,ee,ff,gg,hh, ii,jj,kk,ll,mm,nn,oo,pp
 // to
@@ -218,6 +232,8 @@ uint8_t *SwapEndian64(const uint8_t *src, const size_t len, const uint8_t blockS
        return tmp;
 }
 
+// takes a uint8_t src array, for len items and reverses the byte order in blocksizes (8,16,32,64), 
+// returns: the dest array contains the reordered src array.
 void SwapEndian64ex(const uint8_t *src, const size_t len, const uint8_t blockSize, uint8_t *dest){
        for (uint8_t block=0; block < (uint8_t)(len/blockSize); block++){
                for (size_t i = 0; i < blockSize; i++){
@@ -226,7 +242,6 @@ void SwapEndian64ex(const uint8_t *src, const size_t len, const uint8_t blockSiz
        }
 }
 
-
 //  -------------------------------------------------------------------------
 //  string parameters lib
 //  -------------------------------------------------------------------------
@@ -491,6 +506,7 @@ void wiegand_add_parity(uint8_t *target, uint8_t *source, uint8_t length)
     *(target)= GetParity(source + length / 2, ODD, length / 2);
 }
 
+// xor two arrays together for len items.  The dst array contains the new xored values.
 void xor(unsigned char * dst, unsigned char * src, size_t len) {
    for( ; len > 0; len--,dst++,src++)
        *dst ^= *src;
@@ -500,6 +516,7 @@ int32_t le24toh (uint8_t data[3]) {
     return (data[2] << 16) | (data[1] << 8) | data[0];
 }
 
+// Pack a bitarray into a uint32_t.  
 uint32_t PackBits(uint8_t start, uint8_t len, uint8_t* bits) {
 
        if (len > 32) return 0;
@@ -524,6 +541,7 @@ void rol(uint8_t *data, const size_t len){
     data[len-1] = first;
 }
 
+// Swap bit order on a uint32_t value.  Can be limited by nrbits just use say 8bits reversal
 uint32_t SwapBits(uint32_t value, int nrbits) {
        uint32_t newvalue = 0;
        for(int i = 0; i < nrbits; i++) {