/* 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 *//* OCB Implementation by Tom St Denis */#include "mycrypt.h"#ifdef OCB_MODEint ocb_decrypt_verify_memory(int cipher,    const unsigned char *key,    unsigned long keylen,    const unsigned char *nonce,      const unsigned char *ct,     unsigned long ctlen,          unsigned char *pt,    const unsigned char *tag,    unsigned long taglen,          int           *res){   int err;   ocb_state ocb;   _ARGCHK(key    != NULL);   _ARGCHK(nonce  != NULL);   _ARGCHK(pt     != NULL);   _ARGCHK(ct     != NULL);   _ARGCHK(tag    != NULL);   _ARGCHK(res    != NULL);   if ((err = ocb_init(&ocb, cipher, key, keylen, nonce)) != CRYPT_OK) {      return err;   }   while (ctlen > (unsigned long)ocb.block_len) {        if ((err = ocb_decrypt(&ocb, ct, pt)) != CRYPT_OK) {           return err;        }        ctlen   -= ocb.block_len;        pt      += ocb.block_len;        ct      += ocb.block_len;   }   return ocb_done_decrypt(&ocb, ct, ctlen, pt, tag, taglen, res);}#endif