/* LibTomCrypt, modular cryptographic library -- Tom St Denis * * LibTomCrypt is a library that provides various cryptographic * algorithms in a highly modular and flexible manner. * * The library is free for all purposes without any express * guarantee it works. * * Tom St Denis, tomstdenis@iahu.ca, http://libtomcrypt.org *//* OMAC1 Support by Tom St Denis (for 64 and 128 bit block ciphers only) */#include "mycrypt.h"#ifdef OMACint omac_file(int cipher,               const unsigned char *key, unsigned long keylen,              const char *filename,                     unsigned char *out, unsigned long *outlen){#ifdef NO_FILE   return CRYPT_NOP;#else   int err, x;   omac_state omac;   FILE *in;   unsigned char buf[512];   _ARGCHK(key      != NULL);   _ARGCHK(filename != NULL);   _ARGCHK(out      != NULL);   _ARGCHK(outlen   != NULL);   in = fopen(filename, "rb");   if (in == NULL) {      return CRYPT_FILE_NOTFOUND;   }   if ((err = omac_init(&omac, cipher, key, keylen)) != CRYPT_OK) {      fclose(in);      return err;   }   do {      x = fread(buf, 1, sizeof(buf), in);      if ((err = omac_process(&omac, buf, x)) != CRYPT_OK) {         fclose(in);         return err;      }   } while (x == sizeof(buf));   fclose(in);   if ((err = omac_done(&omac, out, outlen)) != CRYPT_OK) {      return err;   }#ifdef CLEAN_STACK   zeromem(buf, sizeof(buf));#endif   return CRYPT_OK;#endif}#endif