cshake_pattern.c File Reference

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Functions
VOID SYMCRYPT_CALL	SYMCRYPT_Xxx (_In_reads_(cbFunctionNameString) PCBYTE pbFunctionNameString, SIZE_T cbFunctionNameString, _In_reads_(cbCustomizationString) PCBYTE pbCustomizationString, SIZE_T cbCustomizationString, _In_reads_(cbData) PCBYTE pbData, SIZE_T cbData, _Out_writes_(cbResult) PBYTE pbResult, SIZE_T cbResult)
VOID SYMCRYPT_CALL	SYMCRYPT_XxxInit (_Out_ PSYMCRYPT_XXX_STATE pState, _In_reads_(cbFunctionNameString) PCBYTE pbFunctionNameString, SIZE_T cbFunctionNameString, _In_reads_(cbCustomizationString) PCBYTE pbCustomizationString, SIZE_T cbCustomizationString)
VOID SYMCRYPT_CALL	SYMCRYPT_XxxAppend (_Inout_ PSYMCRYPT_XXX_STATE pState, _In_reads_(cbData) PCBYTE pbData, SIZE_T cbData)
VOID SYMCRYPT_CALL	SYMCRYPT_XxxExtract (_Inout_ PSYMCRYPT_XXX_STATE pState, _Out_writes_(cbResult) PBYTE pbResult, SIZE_T cbResult, BOOLEAN bWipe)
VOID SYMCRYPT_CALL	SYMCRYPT_XxxResult (_Inout_ PSYMCRYPT_XXX_STATE pState, _Out_writes_(SYMCRYPT_CSHAKEXXX_RESULT_SIZE) PBYTE pbResult)
VOID SYMCRYPT_CALL	SYMCRYPT_XxxStateCopy (_In_ const SYMCRYPT_XXX_STATE *pSrc, _Out_ SYMCRYPT_XXX_STATE *pDst)

Function Documentation

SYMCRYPT_Xxx()

VOID SYMCRYPT_CALL SYMCRYPT_Xxx	(	_In_reads_(cbFunctionNameString) PCBYTE	pbFunctionNameString,
		SIZE_T	cbFunctionNameString,
		_In_reads_(cbCustomizationString) PCBYTE	pbCustomizationString,
		SIZE_T	cbCustomizationString,
		_In_reads_(cbData) PCBYTE	pbData,
		SIZE_T	cbData,
		_Out_writes_(cbResult) PBYTE	pbResult,
		SIZE_T	cbResult
	)

Definition at line 23 of file cshake_pattern.c.

{
    SYMCRYPT_XXX_STATE state;
 
    SYMCRYPT_XxxInit(&state,
                    pbFunctionNameString, cbFunctionNameString,
                    pbCustomizationString, cbCustomizationString);
 
    SYMCRYPT_XxxAppend(&state, pbData, cbData);
    SYMCRYPT_XxxExtract(&state, pbResult, cbResult, TRUE);
}

SYMCRYPT_XxxAppend()

VOID SYMCRYPT_CALL SYMCRYPT_XxxAppend	(	_Inout_ PSYMCRYPT_XXX_STATE	pState,
		_In_reads_(cbData) PCBYTE	pbData,
		SIZE_T	cbData
	)

Definition at line 82 of file cshake_pattern.c.

{
    // Fixing of the padding value
    //
    // SymCryptKeccakAppend will reset the state, switch to absorb mode,
    // and append data to the empty state if the state was in squeeze mode
    // when Append is called. This behavior is equivalent to initializing
    // cSHAKE with empty input strings, which makes cSHAKE a SHAKE instance.
    //
    // cSHAKE and SHAKE have different paddings, so we have to update the
    // padding value in case it was cSHAKE padding before.
    if (pState->ks.squeezeMode)
    {
        pState->ks.paddingValue = SYMCRYPT_SHAKE_PADDING_VALUE;
    }
 
    SymCryptKeccakAppend(&pState->ks, pbData, cbData);
}

SYMCRYPT_XxxExtract()

VOID SYMCRYPT_CALL SYMCRYPT_XxxExtract	(	_Inout_ PSYMCRYPT_XXX_STATE	pState,
		_Out_writes_(cbResult) PBYTE	pbResult,
		SIZE_T	cbResult,
		BOOLEAN	bWipe
	)

Definition at line 109 of file cshake_pattern.c.

{
    SymCryptKeccakExtract(&pState->ks, pbResult, cbResult, bWipe);
 
    if (bWipe)
    {
        // If the state was wiped, set the state as if cSHAKE was initialized
        // with empty strings, which is equivalent to empty SHAKE state.
        // We have no way to store the Function Name string and Customization
        // string information to go back to the initial cSHAKE state.
        pState->ks.paddingValue = SYMCRYPT_SHAKE_PADDING_VALUE;
    }
}

SYMCRYPT_XxxInit()

VOID SYMCRYPT_CALL SYMCRYPT_XxxInit	(	_Out_ PSYMCRYPT_XXX_STATE	pState,
		_In_reads_(cbFunctionNameString) PCBYTE	pbFunctionNameString,
		SIZE_T	cbFunctionNameString,
		_In_reads_(cbCustomizationString) PCBYTE	pbCustomizationString,
		SIZE_T	cbCustomizationString
	)

Definition at line 49 of file cshake_pattern.c.

{
    C_ASSERT( sizeof(SYMCRYPT_XXX_STATE) == sizeof(SYMCRYPT_SHAKEXXX_STATE) );
 
    SYMCRYPT_SHAKEXXX_INIT( (SYMCRYPT_SHAKEXXX_STATE*)pState );
 
    // Perform cSHAKE processing of input strings when any of the input strings is non-empty
    if (cbFunctionNameString != 0 || cbCustomizationString != 0)
    {
        // cSHAKE and SHAKE have different paddings. pState->paddingValue
        // is set to SYMCRYPT_SHAKE_PADDING_VALUE in the SHAKE initialization above.
        // We update the padding value here because at least one of the input strings
        // is non-empty and cSHAKE will not default to SHAKE.
        pState->ks.paddingValue = SYMCRYPT_CSHAKE_PADDING_VALUE;
 
        SymCryptCShakeEncodeInputStrings(&pState->ks,
                                        pbFunctionNameString, cbFunctionNameString,
                                        pbCustomizationString, cbCustomizationString);
    }
 
    SYMCRYPT_SET_MAGIC(pState);
}

SYMCRYPT_XxxResult()

VOID SYMCRYPT_CALL SYMCRYPT_XxxResult	(	_Inout_ PSYMCRYPT_XXX_STATE	pState,
		_Out_writes_(SYMCRYPT_CSHAKEXXX_RESULT_SIZE) PBYTE	pbResult
	)

Definition at line 132 of file cshake_pattern.c.

{
    SymCryptKeccakExtract(&pState->ks, pbResult, SYMCRYPT_CSHAKEXXX_RESULT_SIZE, TRUE);
 
    // Revert to cSHAKE initialized with empty strings state, i.e., empty SHAKE state
    pState->ks.paddingValue = SYMCRYPT_SHAKE_PADDING_VALUE;
}

SYMCRYPT_XxxStateCopy()

VOID SYMCRYPT_CALL SYMCRYPT_XxxStateCopy	(	_In_ const SYMCRYPT_XXX_STATE *	pSrc,
		_Out_ SYMCRYPT_XXX_STATE *	pDst
	)

Definition at line 147 of file cshake_pattern.c.

{
    SYMCRYPT_CHECK_MAGIC(pSrc);
    *pDst = *pSrc;
    SYMCRYPT_SET_MAGIC(pDst);
}