ippsHashDRBG_Reseed

ippsHashDRBG_Reseed#

Reseeds the Hash DRBG state with new entropy.

Syntax#

IppStatus ippsHashDRBG_Reseed(const int predictionResistanceRequest,
                              const Ipp8u* addlInput,
                              const int addlInputBitsLen,
                              IppsHashDRBG_EntropyInputCtx* pEntrInputCtx,
                              IppsHashDRBGState* pDrbgCtx);

Include Files#

ippcp.h

Parameters#

predictionResistanceRequest

Indicates whether or not prediction resistance is to be provided during the request (whether or not fresh entropy bits are required).

addlInput

Pointer to the array containing additional input (optional).

addlInputBitsLen

Length of the addlInput string in bits (may be zero).

pEntrInputCtx

Pointer to the Entropy input context. The size is equal to the value returned by ippsHashDRBG_EntropyInputCtxGetSize.

pDrbgCtx

Pointer to the IppsHashDRBGState context. The size is equal to the value returned by ippsHashDRBG_GetSize.

Note

The minimum length of the entropy input shall be equal to or greater than the security strength.

Description#

The reseed function:

  • Obtains entropy input using the following priority order:

    1. Custom callback: calls getEntropyInput() if not NULL.

    2. Hardware RDSEED: calls ippsTRNGenRDSEED() if CPU supports RDSEED instruction.

    3. Hardware RDRAND: calls ippsPRNGenRDRAND() if CPU supports RDRAND instruction.

    Checks whether the entropy is sufficient to support the security strength.

  • Using the reseed algorithm, combines the current seed from the state with the new entropy input and any additional input and updates the state.

Return Values#

ippStsNoErr

Indicates no error. All single operations executed without errors. Any other value indicates an error.

ippStsNullPtrErr

pDrbgCtx or pEntrInputCtx is a NULL pointer. The pointer to the buffer that contains the entropy input is NULL.

ippStsContextMatchErr

If the Hash DRBG identifier doesn’t match. If the Entropy input context identifier doesn’t match.

ippStsOutOfRangeErr

The length of the addlInput exceeds the maximum possible value. The length for the entropy input, passed to the getEntropyInput callback function, is less than the security strength or exceeds the maximum number of bits that can fit in the entropyInput buffer.

ippStsBadArgErr

Prediction resistance is requested but predictionResistanceFlag has been set to 0. The addlInput is NULL with non-zero addlInputBitsLen, or the addlInput is not NULL, but addlInputBitsLen is 0.

ippStsNotSupportedModeErr

The CPU supports neither RDSEED nor RDRAND instructions.

ippStsHashOperationErr

An error status code was returned during hashing operations.
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