OSX/authd/crc.h

   1 /* Copyright (c) 2012 Apple Inc. All Rights Reserved. */
   2
   3 #ifndef _SECURITY_AUTH_CRC_H_
   4 #define _SECURITY_AUTH_CRC_H_
   5
   6 #if defined(__cplusplus)
   7 extern "C" {
   8 #endif
   9
  10 extern const uint64_t _crc_table64[256];
  11 extern const uint64_t xorout;
  12
  13 AUTH_INLINE uint64_t
  14 crc64_init()
  15 {
  16     return xorout;
  17 }
  18
  19 AUTH_INLINE uint64_t
  20 crc64_final(uint64_t crc)
  21 {
  22       return crc ^ xorout;
  23 }
  24
  25 AUTH_INLINE AUTH_NONNULL_ALL uint64_t
  26 crc64_update(uint64_t crc, const void *buf, uint64_t len)
  27 {
  28     const unsigned char * ptr = (const unsigned char *) buf;
  29
  30     while (len-- > 0) {
  31         crc = _crc_table64[((crc >> 56) ^ *(ptr++)) & 0xff] ^ (crc << 8);
  32     }
  33
  34     return crc;
  35 }
  36
  37 AUTH_INLINE uint64_t
  38 crc64(const void *buf, uint64_t len)
  39 {
  40     uint64_t crc = crc64_init();
  41
  42     crc = crc64_update(crc, buf, len);
  43
  44     crc = crc64_final(crc);
  45
  46     return crc;
  47 }
  48
  49 #if defined(__cplusplus)
  50 }
  51 #endif
  52
  53 #endif /* !_SECURITY_AUTH_CRC_H_ */