TDESDecryptCFB

Decrypts variable length data stream in the CFB mode (deprecated).

Syntax

IppStatus ippsTDESDecryptCFB(const Ipp8u *pSrc, Ipp8u *pDst, int length, int cfbBlkSize, const IppsDESSpec *pCtx1, const IppsDESSpec * pCtx2, const IppsDESSpec *pCtx3, const Ipp8u *pIV, IppsCPPadding padding);

Include Files

ippcp.h

Parameters

pSrc

Input ciphertext data stream of variable length.

pDst

Resulting plaintext data stream.

pIV

Initialization vector for TDES CFB mode operation.

length

Ciphertext data stream length 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.

cfbBlkSize

CFB block size in bytes.

padding

IppsCPPaddingNONE padding scheme.

Description

Note

This algorithm is considered weak due to known attacks on it. The functionality remains in the library, but the implementation will no longer be optimized and no security patches will be applied. A more secure alternative is available: AES.

This function decrypts the input data stream of a variable length according to the cipher scheme specified in [NIST SP 800-38A]. The function uses three sets of the supplied round keys in the Cipher Feedback (CFB) mode with the initialization vector. The function returns the ciphertext result and validates the final plaintext block.

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 decrypted plaintext data stream length is less than or equal to zero.

ippStsCFBSizeErr

Indicates an error condition if the value for cfbBlkSize is illegal.

ippStsContextMatchErr

Indicates an error condition if the context parameter does not match the operation.

ippStsUnderRunErr

Indicates an error condition if length is not divisible by cipher block size.