* Encrypt or decrypt a buffer using a previously initialized context
*
* @param ctx an AVTWOFISH context
* @param dst destination array, can be equal to src
* @param src source array, can be equal to dst
* @param count number of 16 byte blocks
* @paran iv initialization vector for CBC mode, NULL for ECB mode
* @param decrypt 0 for encryption, 1 for decryption
* Encrypt or decrypt a buffer using a previously initialized context * * @param ctx an AVTWOFISH context * @param dst destination array, can be equal to src * @param src source array, can be equal to dst * @param count number of 16 byte blocks * @paran iv initialization vector for CBC mode, NULL for ECB mode * @param decrypt 0 for encryption, 1 for decryption