Update README.md

[proxmark3-svn] / client / util.c

diff --git a/client/util.c b/client/util.c
index 99a26a40ac20160a688139d9a86f59b37a5f4c09..c5c7d7fe2f2fc3d019507426581c84bf43cdea64 100644 (file)
--- a/client/util.c
+++ b/client/util.c
@@ -9,15 +9,13 @@
 //-----------------------------------------------------------------------------
 
 #include "util.h"
-#include "proxmark3.h"
 #define MAX_BIN_BREAK_LENGTH   (3072+384+1)
 
 #ifndef _WIN32
 #include <termios.h>
 #include <sys/ioctl.h> 
 
-int ukbhit(void)
-{
+int ukbhit(void) {
   int cnt = 0;
   int error;
   static struct termios Otty, Ntty;
@@ -186,19 +184,16 @@ char *sprint_hex_ascii(const uint8_t *data, const size_t len) {
        return buf;
 }
 
-void num_to_bytes(uint64_t n, size_t len, uint8_t* dest)
-{
+void num_to_bytes(uint64_t n, size_t len, uint8_t* dest) {
        while (len--) {
                dest[len] = (uint8_t) n;
                n >>= 8;
        }
 }
 
-uint64_t bytes_to_num(uint8_t* src, size_t len)
-{
+uint64_t bytes_to_num(uint8_t* src, size_t len) {
        uint64_t num = 0;
-       while (len--)
-       {
+       while (len--) {
                num = (num << 8) | (*src);
                src++;
        }
@@ -212,6 +207,7 @@ void num_to_bytebits(uint64_t n, size_t len, uint8_t *dest) {
                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) {
@@ -220,13 +216,12 @@ void num_to_bytebitsLSBF(uint64_t n, size_t len, uint8_t *dest) {
        }
 }
 
-
 // aa,bb,cc,dd,ee,ff,gg,hh, ii,jj,kk,ll,mm,nn,oo,pp
 // to
 // hh,gg,ff,ee,dd,cc,bb,aa, pp,oo,nn,mm,ll,kk,jj,ii
 // up to 64 bytes or 512 bits
 uint8_t *SwapEndian64(const uint8_t *src, const size_t len, const uint8_t blockSize){
-       uint8_t buf[64];
+       static uint8_t buf[64];
        memset(buf, 0x00, 64);
        uint8_t *tmp = buf;
        for (uint8_t block=0; block < (uint8_t)(len/blockSize); block++){
@@ -234,7 +229,7 @@ uint8_t *SwapEndian64(const uint8_t *src, const size_t len, const uint8_t blockS
                        tmp[i+(blockSize*block)] = src[(blockSize-1-i)+(blockSize*block)];
                }
        }
-       return tmp;
+       return buf;
 }
 
 // takes a uint8_t src array, for len items and reverses the byte order in blocksizes (8,16,32,64), 
@@ -285,7 +280,6 @@ int param_getptr(const char *line, int *bg, int *en, int paramnum)
        return 0;
 }
 
-
 char param_getchar(const char *line, int paramnum)
 {
        int bg, en;
@@ -357,8 +351,6 @@ uint64_t param_get64ex(const char *line, int paramnum, int deflt, int base)
                return strtoull(&line[bg], NULL, base);
        else
                return deflt;
-
-       return 0;
 }
 
 int param_gethex(const char *line, int paramnum, uint8_t * data, int hexcnt)
@@ -549,10 +541,36 @@ void rol(uint8_t *data, const size_t len){
 }
 
 // Swap bit order on a uint32_t value.  Can be limited by nrbits just use say 8bits reversal
+// And clears the rest of the bits.
 uint32_t SwapBits(uint32_t value, int nrbits) {
        uint32_t newvalue = 0;
        for(int i = 0; i < nrbits; i++) {
                newvalue ^= ((value >> i) & 1) << (nrbits - 1 - i);
        }
        return newvalue;
+}
+/*
+ ref  http://www.csm.ornl.gov/~dunigan/crc.html
+ Returns the value v with the bottom b [0,32] bits reflected. 
+ Example: reflect(0x3e23L,3) == 0x3e26
+*/
+uint32_t reflect(uint32_t v, int b) {
+       uint32_t t = v;
+       for ( int i = 0; i < b; ++i) {
+               if (t & 1)
+                       v |=  BITMASK((b-1)-i);
+               else
+                       v &= ~BITMASK((b-1)-i);
+               t>>=1;
+       }
+       return v;
+}
+
+uint64_t HornerScheme(uint64_t num, uint64_t divider, uint64_t factor) {
+   uint64_t remainder=0, quotient=0, result=0;
+   remainder = num % divider;
+   quotient = num / divider;
+   if(!(quotient == 0 && remainder == 0))
+   result += HornerScheme(quotient, divider, factor) * factor + remainder;
+   return result;
 }
\ No newline at end of file