/* 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@gmail.com, http://libtomcrypt.com */#include "tomcrypt.h"/**  @file ecb_decrypt.c  ECB implementation, decrypt a block, Tom St Denis*/#ifdef LTC_ECB_MODE/**  ECB decrypt  @param ct     Ciphertext  @param pt     [out] Plaintext  @param len    The number of octets to process (must be multiple of the cipher block size)  @param ecb    ECB state  @return CRYPT_OK if successful*/int ecb_decrypt(const unsigned char *ct, unsigned char *pt, unsigned long len, symmetric_ECB *ecb){   int err;   LTC_ARGCHK(pt != NULL);   LTC_ARGCHK(ct != NULL);   LTC_ARGCHK(ecb != NULL);   if ((err = cipher_is_valid(ecb->cipher)) != CRYPT_OK) {       return err;   }   if (len % cipher_descriptor[ecb->cipher].block_length) {      return CRYPT_INVALID_ARG;   }   /* check for accel */   if (cipher_descriptor[ecb->cipher].accel_ecb_decrypt != NULL) {      return cipher_descriptor[ecb->cipher].accel_ecb_decrypt(ct, pt, len / cipher_descriptor[ecb->cipher].block_length, &ecb->key);   } else {      while (len) {         if ((err = cipher_descriptor[ecb->cipher].ecb_decrypt(ct, pt, &ecb->key)) != CRYPT_OK) {            return err;         }         pt  += cipher_descriptor[ecb->cipher].block_length;         ct  += cipher_descriptor[ecb->cipher].block_length;         len -= cipher_descriptor[ecb->cipher].block_length;      }   }   return CRYPT_OK;}#endif/* $Source: /cvs/libtom/libtomcrypt/src/modes/ecb/ecb_decrypt.c,v $ *//* $Revision: 1.9 $ *//* $Date: 2006/06/29 01:51:34 $ */