hmac.c File Reference

#include "precomp.h"

Include dependency graph for hmac.c:

Go to the source code of this file.

Functions
VOID SYMCRYPT_CALL	SymCryptHmacStateCopy (_In_ PCSYMCRYPT_HMAC_STATE pSrc, _In_opt_ PCSYMCRYPT_HMAC_EXPANDED_KEY pExpandedKey, _Out_ PSYMCRYPT_HMAC_STATE pDst)
VOID SYMCRYPT_CALL	SymCryptHmacKeyCopy (_In_ PCSYMCRYPT_HMAC_EXPANDED_KEY pSrc, _Out_ PSYMCRYPT_HMAC_EXPANDED_KEY pDst)
SYMCRYPT_ERROR SYMCRYPT_CALL	SymCryptHmacExpandKey (_In_ PCSYMCRYPT_HASH pHash, _Out_ PSYMCRYPT_HMAC_EXPANDED_KEY pExpandedKey, _In_reads_opt_(cbKey) PCBYTE pbKey, SIZE_T cbKey)
SYMCRYPT_NOINLINE VOID SYMCRYPT_CALL	SymCryptHmacInit (_Out_ PSYMCRYPT_HMAC_STATE pState, _In_ PCSYMCRYPT_HMAC_EXPANDED_KEY pExpandedKey)
VOID SYMCRYPT_CALL	SymCryptHmacAppend (_Inout_ PSYMCRYPT_HMAC_STATE pState, _In_reads_(cbData) PCBYTE pbData, SIZE_T cbData)
SYMCRYPT_NOINLINE VOID SYMCRYPT_CALL	SymCryptHmacResult (_Inout_ PSYMCRYPT_HMAC_STATE pState, _Out_writes_(pState->pKey->pHash->resultSize) PBYTE pbResult)
SYMCRYPT_NOINLINE VOID SYMCRYPT_CALL	SymCryptHmac (_In_ PCSYMCRYPT_HMAC_EXPANDED_KEY pExpandedKey, _In_reads_(cbData) PCBYTE pbData, SIZE_T cbData, _Out_writes_(pExpandedKey->pHash->resultSize) PBYTE pbResult)

Function Documentation

SymCryptHmac()

SYMCRYPT_NOINLINE VOID SYMCRYPT_CALL SymCryptHmac	(	_In_ PCSYMCRYPT_HMAC_EXPANDED_KEY	pExpandedKey,
		_In_reads_(cbData) PCBYTE	pbData,
		SIZE_T	cbData,
		_Out_writes_(pExpandedKey->pHash->resultSize) PBYTE	pbResult
	)

Definition at line 184 of file hmac.c.

{
    SYMCRYPT_HMAC_STATE state;
 
    SymCryptHmacInit( &state, pExpandedKey );
    SymCryptHmacAppend( &state, pbData, cbData );
    SymCryptHmacResult( &state, pbResult );
}

Referenced by SymCryptHmacSha3_224(), SymCryptHmacSha3_256(), SymCryptHmacSha3_384(), and SymCryptHmacSha3_512().

SymCryptHmacAppend()

VOID SYMCRYPT_CALL SymCryptHmacAppend	(	_Inout_ PSYMCRYPT_HMAC_STATE	pState,
		_In_reads_(cbData) PCBYTE	pbData,
		SIZE_T	cbData
	)

Definition at line 130 of file hmac.c.

{
    SymCryptHashAppend( pState->pKey->pHash, &pState->hash, pbData, cbData );
}

Referenced by SymCryptHmac(), SymCryptHmacSha3_224Append(), SymCryptHmacSha3_256Append(), SymCryptHmacSha3_384Append(), and SymCryptHmacSha3_512Append().

SymCryptHmacExpandKey()

SYMCRYPT_ERROR SYMCRYPT_CALL SymCryptHmacExpandKey	(	_In_ PCSYMCRYPT_HASH	pHash,
		_Out_ PSYMCRYPT_HMAC_EXPANDED_KEY	pExpandedKey,
		_In_reads_opt_(cbKey) PCBYTE	pbKey,
		SIZE_T	cbKey
	)

Definition at line 53 of file hmac.c.

{
    // This buffer has to be large enough to hold one input block
    // and the result of the hash function.
    // Using SHA3-224 input block size to satisfy those requirements.
    SYMCRYPT_ALIGN BYTE iblock[ SYMCRYPT_SHA3_224_INPUT_BLOCK_SIZE ];
 
    SYMCRYPT_ASSERT( sizeof(iblock) >= pHash->inputBlockSize );
    SYMCRYPT_ASSERT( sizeof(iblock) >= pHash->resultSize );
 
    // XorByteIntoBuffer function updates the buffer in multiples of 8-bytes
    SYMCRYPT_ASSERT( pHash->inputBlockSize % 8 == 0);
 
    memset( iblock, 0, sizeof( iblock ) );
 
    if( cbKey <= pHash->inputBlockSize )
    {
        if( cbKey > 0 )
        {
            memcpy( iblock, pbKey, cbKey );
        }
    }
    else
    {
        SymCryptHash( pHash, pbKey, cbKey, iblock, pHash->resultSize );
    }
 
    XorByteIntoBuffer( iblock, pHash->inputBlockSize / 8, HMAC_IPAD_BYTE );
 
    //
    // Initialize the inner and outer states in the expanded key
    //
    SymCryptHashInit( pHash, &pExpandedKey->innerState );
    SymCryptHashInit( pHash, &pExpandedKey->outerState );
 
    // Update the inner state in the expanded key
    SymCryptHashAppend( pHash, &pExpandedKey->innerState, iblock, pHash->inputBlockSize );
 
    XorByteIntoBuffer( iblock, pHash->inputBlockSize / 8, HMAC_IPAD_BYTE ^ HMAC_OPAD_BYTE );
 
    // Update the outer state in the expanded key
    SymCryptHashAppend( pHash, &pExpandedKey->outerState, iblock, pHash->inputBlockSize );
 
    SymCryptWipeKnownSize( iblock, sizeof( iblock ) );
 
    // Save the hash function in the expanded key, it will be used in other
    // generic HMAC function calls.
    pExpandedKey->pHash = pHash;
 
    SYMCRYPT_SET_MAGIC(pExpandedKey);
 
    return SYMCRYPT_NO_ERROR;
}

Referenced by SymCryptHmacSha3_224ExpandKey(), SymCryptHmacSha3_256ExpandKey(), SymCryptHmacSha3_384ExpandKey(), and SymCryptHmacSha3_512ExpandKey().

SymCryptHmacInit()

SYMCRYPT_NOINLINE VOID SYMCRYPT_CALL SymCryptHmacInit	(	_Out_ PSYMCRYPT_HMAC_STATE	pState,
		_In_ PCSYMCRYPT_HMAC_EXPANDED_KEY	pExpandedKey
	)

Definition at line 115 of file hmac.c.

{
    SYMCRYPT_CHECK_MAGIC( pExpandedKey );
 
    SymCryptHashStateCopy( pExpandedKey->pHash, &pExpandedKey->innerState, &pState->hash );
 
    pState->pKey = pExpandedKey;
 
    SYMCRYPT_SET_MAGIC(pState);
}

Referenced by SymCryptHmac(), SymCryptHmacSha3_224Init(), SymCryptHmacSha3_256Init(), SymCryptHmacSha3_384Init(), and SymCryptHmacSha3_512Init().

SymCryptHmacKeyCopy()

VOID SYMCRYPT_CALL SymCryptHmacKeyCopy	(	_In_ PCSYMCRYPT_HMAC_EXPANDED_KEY	pSrc,
		_Out_ PSYMCRYPT_HMAC_EXPANDED_KEY	pDst
	)

Definition at line 36 of file hmac.c.

{
    SYMCRYPT_CHECK_MAGIC( pSrc );
 
    // Copy innerState and outerState
    SymCryptHashStateCopy(pSrc->pHash, &pSrc->innerState, &pDst->innerState );
    SymCryptHashStateCopy(pSrc->pHash, &pSrc->outerState, &pDst->outerState );
 
    pDst->pHash = pSrc->pHash;
 
    SYMCRYPT_SET_MAGIC( pDst );
}

Referenced by SymCryptHmacSha3_224KeyCopy(), SymCryptHmacSha3_256KeyCopy(), SymCryptHmacSha3_384KeyCopy(), and SymCryptHmacSha3_512KeyCopy().

SymCryptHmacResult()

SYMCRYPT_NOINLINE VOID SYMCRYPT_CALL SymCryptHmacResult	(	_Inout_ PSYMCRYPT_HMAC_STATE	pState,
		_Out_writes_(pState->pKey->pHash->resultSize) PBYTE	pbResult
	)

Definition at line 141 of file hmac.c.

{
    BYTE    innerRes[64];
 
    PCSYMCRYPT_HASH pHash = pState->pKey->pHash;
 
    SYMCRYPT_ASSERT(sizeof(innerRes) >= pHash->resultSize);
 
    SYMCRYPT_CHECK_MAGIC( pState );
 
    //
    // We have to buffer the inner hash result. We can't put it directly in the
    // hash state data buffer as the Result() function wipes that buffer before returning.
    //
    SymCryptHashResult( pHash, &pState->hash, innerRes, pHash->resultSize );
 
    SYMCRYPT_CHECK_MAGIC( pState->pKey )
 
    SymCryptHashStateCopy( pHash, &pState->pKey->outerState, &pState->hash );
 
    SymCryptHashAppend( pHash, &pState->hash, innerRes, pHash->resultSize );
 
    SymCryptHashResult( pHash, &pState->hash, pbResult, pHash->resultSize );
 
    //
    // The SymCryptHashResult already wipes the hash state.
    // We only need to wipe our own buffer.
    //
    // We also set the key pointer to NULL. This is not for security;
    // it creates a clear error when callers forget to call the Init routine
    // when re-using a state. Rather than the wrong result, they will get
    // a NULL pointer exception, and they will fix their code.
    //
 
    SymCryptWipeKnownSize( innerRes, sizeof( innerRes ) );
    pState->pKey = NULL;
}

Referenced by SymCryptHmac(), SymCryptHmacSha3_224Result(), SymCryptHmacSha3_256Result(), SymCryptHmacSha3_384Result(), and SymCryptHmacSha3_512Result().

SymCryptHmacStateCopy()

VOID SYMCRYPT_CALL SymCryptHmacStateCopy	(	_In_ PCSYMCRYPT_HMAC_STATE	pSrc,
		_In_opt_ PCSYMCRYPT_HMAC_EXPANDED_KEY	pExpandedKey,
		_Out_ PSYMCRYPT_HMAC_STATE	pDst
	)

Definition at line 10 of file hmac.c.

{
    SYMCRYPT_CHECK_MAGIC( pSrc );
 
    PCSYMCRYPT_HASH pHash = pSrc->pKey->pHash;
 
    SymCryptHashStateCopy( pHash, &pSrc->hash, &pDst->hash );
 
    if( pExpandedKey != NULL )
    {
        SYMCRYPT_CHECK_MAGIC( pExpandedKey );
        pDst->pKey = pExpandedKey;
    }
    else
    {
        SYMCRYPT_CHECK_MAGIC( pSrc->pKey );
        pDst->pKey = pSrc->pKey;
    }
    SYMCRYPT_SET_MAGIC( pDst );
}

Referenced by SymCryptHmacSha3_224StateCopy(), SymCryptHmacSha3_256StateCopy(), SymCryptHmacSha3_384StateCopy(), and SymCryptHmacSha3_512StateCopy().