proxmark3/common/commonutil.c
Philippe Teuwen eababdd3ef Merge branch 'master' into experimental_varlen
* master:
  chg: 'hf mf sim' - textual
  fix:  warning on mingw64.   This offset is calculated, casting it to u32 should be fine.
  fix: https://github.com/RfidResearchGroup/proxmark3/issues/174 remove all offending code,  return 1.   Will only impact the speed of hardnested execution.
  fix again OSX
  fix https://github.com/RfidResearchGroup/proxmark3/issues/173
  used predefined constants, common types moved to common header files
  backward compatibility, on load converter for old mfu dump format
  loops for counters output
  UL/NTAG new dump file format. Added counters support, simulation
2019-04-25 20:05:04 +02:00

95 lines
2.5 KiB
C

//-----------------------------------------------------------------------------
// Jonathan Westhues, Sept 2005
//
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// Utility functions used in many places, not specific to any piece of code.
//-----------------------------------------------------------------------------
#include "commonutil.h"
/*
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;
}
uint8_t reflect8(uint8_t b) {
return ((b * 0x80200802ULL) & 0x0884422110ULL) * 0x0101010101ULL >> 32;
}
uint16_t reflect16(uint16_t b) {
uint16_t v = 0;
v |= (b & 0x8000) >> 15;
v |= (b & 0x4000) >> 13;
v |= (b & 0x2000) >> 11;
v |= (b & 0x1000) >> 9;
v |= (b & 0x0800) >> 7;
v |= (b & 0x0400) >> 5;
v |= (b & 0x0200) >> 3;
v |= (b & 0x0100) >> 1;
v |= (b & 0x0080) << 1;
v |= (b & 0x0040) << 3;
v |= (b & 0x0020) << 5;
v |= (b & 0x0010) << 7;
v |= (b & 0x0008) << 9;
v |= (b & 0x0004) << 11;
v |= (b & 0x0002) << 13;
v |= (b & 0x0001) << 15;
return v;
}
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 num = 0;
while (len--) {
num = (num << 8) | (*src);
src++;
}
return num;
}
// RotateLeft - Ultralight, Desfire
void rol(uint8_t *data, const size_t len) {
uint8_t first = data[0];
for (size_t i = 0; i < len - 1; i++) {
data[i] = data[i + 1];
}
data[len - 1] = first;
}
void lsl(uint8_t *data, size_t len) {
for (size_t n = 0; n < len - 1; n++) {
data[n] = (data[n] << 1) | (data[n + 1] >> 7);
}
data[len - 1] <<= 1;
}
int32_t le24toh(uint8_t data[3]) {
return (data[2] << 16) | (data[1] << 8) | data[0];
}
void htole24(uint32_t val, uint8_t data[3]) {
data[0] = (uint8_t) val;
data[1] = (uint8_t)(val >> 8);
data[2] = (uint8_t)(val >> 16);
}