TDESDecryptOFB

Decrypts a variable length data stream according to the TDES algorithm in the OFB mode.

Syntax

IppStatus ippsTDESDecryptOFB (const Ipp8u* pSrc, Ipp8u* pDst, int srclen, int ofbBlkSize, const IppsDESSpec *pCtx1, const IppsDESSpec * pCtx2, const IppsDESSpec *pCtx3, Ipp8u* pIV);

Parameters

pSrc	Pointer to the input ciphertext data stream of variable length.
pDst	Pointer to the resulting plaintext data stream.
srclen	Length of the ciphertext data stream in bytes.
ofbBlkSize	Size of the OFB block in bytes.
pCtx1	First set of round keys scheduled for TDES internal operations.
pCtx2	Second set of round keys scheduled for TDES internal operations.
pCtx3	Third set of round keys scheduled for TDES internal operations.
pIV	Pointer to the initialization vector for the OFB mode operation.

Description

This function is declared in the ippcp.h file. The function decrypts the input data stream of a variable length in the OFB mode as specified in [NIST SP 800-38A].

Return Values

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.