.. _aesencryptofb:


AESEncryptOFB
=============


Encrypts a variable length data stream according to AES in the OFB mode.


Syntax
------


IppStatus ippsAESEncryptOFB (const Ipp8u\* pSrc, Ipp8u\* pDst, int
srclen, int ofbBlkSize, const IppsAESSpec\* pCtx, Ipp8u\* pIV);


Include Files
-------------


``ippcp.h``


Parameters
----------


.. list-table:: 
   :header-rows: 0

   * - pSrc    
     - Pointer to the input plaintext data stream of variable length.
   * - pDst   
     - Pointer to the resulting ciphertext data stream.
   * - srclen   
     - Length of the plaintext data stream in bytes.
   * - ofbBlkSize    
     - Size of the OFB block in bytes.
   * - pCtx   
     - Pointer to the IppsAESSpec context.
   * - pIV    
     - Pointer to the initialization vector for the OFB mode operation.




Description
-----------


The function encrypts the input data stream of a variable length in the
OFB mode as specified in [`NIST SP
800-38A <bibliography.html>`__].


Return Values
-------------


.. list-table:: 
   :header-rows: 0

   * - ippStsNoErr   
     - Indicates no error. Any other value indicates an error or warning.
   * - ippStsNullPtrErr   
     - Indicates an error condition if any of the specified pointers is NULL.
   * - ippStsLengthErr    
     - Indicates an error condition if the input data stream length is less than or equal to zero.
   * - ippStsUnderRunErr    
     - Indicates an error condition if srclen is not divisible by the ofbBlkSize parameter value.
   * - ippStsOFBSizeErr    
     - Indicates an error condition if the value of ofbBlkSize is illegal.
   * - ippStsContextMatchErr   
     - Indicates an error condition if the context parameter does not match the operation.