sign_int.c

cryptlib安全工具包

	/* Make sure that the requested signature format is available */
	if( writeSigFunction == NULL )
		return( CRYPT_ERROR_NOTAVAIL );

	/* Extract general information */
	status = krnlSendMessage( iSignContext, IMESSAGE_GETATTRIBUTE, &signAlgo,
							  CRYPT_CTXINFO_ALGO );
	if( cryptStatusError( status ) )
		return( cryptArgError( status ) ? CRYPT_ARGERROR_NUM1 : status );
	status = krnlSendMessage( iHashContext, IMESSAGE_GETATTRIBUTE,
							  &hashAlgo, CRYPT_CTXINFO_ALGO );
	if( cryptStatusError( status ) )
		return( cryptArgError( status ) ? CRYPT_ARGERROR_NUM2 : status );

	/* DLP and ECC signatures are handled somewhat specially */
	if( isDlpAlgo( signAlgo ) || isEccAlgo( signAlgo ) )
		{
		status = createDlpSignature( bufPtr, bufSize, &length, iSignContext, 
									 iHashContext, signatureType );
		}
	else
		{
		MECHANISM_SIGN_INFO mechanismInfo;

		/* It's a standard signature, process it as normal */
		setMechanismSignInfo( &mechanismInfo, bufPtr, bufSize, iHashContext, 
							  iHashContext2, iSignContext );
		status = krnlSendMessage( iSignContext, IMESSAGE_DEV_SIGN, &mechanismInfo,
								  ( signatureType == SIGNATURE_SSL ) ? \
									MECHANISM_SIG_SSL : MECHANISM_SIG_PKCS1 );
		if( cryptStatusOK( status ) )
			length = mechanismInfo.signatureLength;
		clearMechanismInfo( &mechanismInfo );
		}
	if( cryptStatusError( status ) )
		{
		/* The mechanism messages place the acted-on object (in this case the
		   hash context) first while the higher-level functions place the
		   signature context next to the signature data, in other words
		   before the hash context.  Because of this we have to reverse
		   parameter error values when translating from the mechanism to the
		   signature function level */
		if( bufPtr != NULL )
			zeroise( bufPtr, CRYPT_MAX_PKCSIZE );
		return( ( status == CRYPT_ARGERROR_NUM1 ) ? \
					CRYPT_ARGERROR_NUM2 : \
				( status == CRYPT_ARGERROR_NUM2 ) ? \
					CRYPT_ARGERROR_NUM1 : status );
		}

	/* If we're perfoming a dummy sign for a length check, set up a dummy 
	   value to write */
	if( signature == NULL )
		memset( buffer, 0x01, length );

	/* Write the signature record to the output */
	sMemOpenOpt( &stream, signature, sigMaxLength );
	status = writeSigFunction( &stream, iSignContext, hashAlgo, signAlgo,
							   buffer, length );
	if( cryptStatusOK( status ) )
		*signatureLength = stell( &stream );
	sMemDisconnect( &stream );

	/* Clean up */
	zeroise( buffer, CRYPT_MAX_PKCSIZE );
	return( status );
	}

/****************************************************************************
*																			*
*								Check a Signature							*
*																			*
****************************************************************************/

/* Common signature-checking routine, used by other sign_xxx.c modules */

CHECK_RETVAL STDC_NONNULL_ARG( ( 1 ) ) \
int checkSignature( IN_BUFFER( signatureLength ) const void *signature, 
					IN_LENGTH_SHORT const int signatureLength,
					IN_HANDLE const CRYPT_CONTEXT iSigCheckContext,
					IN_HANDLE const CRYPT_CONTEXT iHashContext,
					IN_HANDLE_OPT const CRYPT_CONTEXT iHashContext2,
					IN_ENUM( SIGNATURE ) const SIGNATURE_TYPE signatureType )
	{
	CRYPT_ALGO_TYPE signAlgo, hashAlgo;
	MECHANISM_SIGN_INFO mechanismInfo;
	const READSIG_FUNCTION readSigFunction = getReadSigFunction( signatureType );
	QUERY_INFO queryInfo;
	STREAM stream;
	void *signatureData;
	int signatureDataLength, status;

	assert( isReadPtr( signature, signatureLength ) );
	
	REQUIRES( signatureLength > 40 && \
			  signatureLength < MAX_INTLENGTH_SHORT );
	REQUIRES( isHandleRangeValid( iSigCheckContext ) );
	REQUIRES( isHandleRangeValid( iHashContext ) );
	REQUIRES( ( signatureType == SIGNATURE_SSL && \
				isHandleRangeValid( iHashContext2 ) ) || \
			  ( ( signatureType == SIGNATURE_CMS || \
				  signatureType == SIGNATURE_CRYPTLIB || \
				  signatureType == SIGNATURE_PGP || \
				  signatureType == SIGNATURE_RAW || \
				  signatureType == SIGNATURE_SSH || \
				  signatureType == SIGNATURE_X509 ) && \
				iHashContext2 == CRYPT_UNUSED ) );

	/* Make sure that the requested signature format is available */
	if( readSigFunction == NULL )
		return( CRYPT_ERROR_NOTAVAIL );

	/* Extract general information */
	status = krnlSendMessage( iSigCheckContext, IMESSAGE_GETATTRIBUTE,
							  &signAlgo, CRYPT_CTXINFO_ALGO );
	if( cryptStatusError( status ) )
		return( cryptArgError( status ) ? CRYPT_ARGERROR_NUM1 : status );
	status = krnlSendMessage( iHashContext, IMESSAGE_GETATTRIBUTE,
							  &hashAlgo, CRYPT_CTXINFO_ALGO );
	if( cryptStatusError( status ) )
		return( cryptArgError( status ) ? CRYPT_ARGERROR_NUM2 : status );

	/* Read and check the signature record */
	memset( &queryInfo, 0, sizeof( QUERY_INFO ) );
	sMemConnect( &stream, signature, signatureLength );
 	status = readSigFunction( &stream, &queryInfo );
	sMemDisconnect( &stream );
	if( cryptStatusError( status ) )
		{
		zeroise( &queryInfo, sizeof( QUERY_INFO ) );
		return( status );
		}

	/* Make sure that we've been given the correct algorithms.  Raw
	   signatures specify the algorithm information elsewhere so the check
	   is done at a higher level when we process the signature data */
	if( signatureType != SIGNATURE_RAW && signatureType != SIGNATURE_SSL )
		{
		if( signAlgo != queryInfo.cryptAlgo )
			status = CRYPT_ERROR_SIGNATURE;
		if( signatureType != SIGNATURE_SSH && \
			hashAlgo != queryInfo.hashAlgo )
			status = CRYPT_ERROR_SIGNATURE;
		if( cryptStatusError( status ) )
			{
			zeroise( &queryInfo, sizeof( QUERY_INFO ) );
			return( status );
			}
		}

	/* Make sure that we've been given the correct key if the signature
	   format supports this type of check.  SIGNATURE_CMS supports a check
	   with MESSAGE_COMPARE_ISSUERANDSERIALNUMBER but this has already been
	   done while procesing the other CMS data before we were called so we
	   don't need to do it again */
	if( signatureType == SIGNATURE_CRYPTLIB || \
		signatureType == SIGNATURE_PGP )
		{
		MESSAGE_DATA msgData;

		setMessageData( &msgData, queryInfo.keyID, queryInfo.keyIDlength );
		status = krnlSendMessage( iSigCheckContext, IMESSAGE_COMPARE,
								  &msgData, 
								  ( signatureType == SIGNATURE_CRYPTLIB ) ? \
									MESSAGE_COMPARE_KEYID : \
								  ( queryInfo.version == PGP_VERSION_2 ) ? \
									MESSAGE_COMPARE_KEYID_PGP : \
									MESSAGE_COMPARE_KEYID_OPENPGP );
		if( cryptStatusError( status ) )
			{
			/* A failed comparison is reported as a generic CRYPT_ERROR,
			   convert it into a wrong-key error if necessary */
			zeroise( &queryInfo, sizeof( QUERY_INFO ) );
			return( ( status == CRYPT_ERROR ) ? \
					CRYPT_ERROR_WRONGKEY : status );
			}
		}
	REQUIRES( rangeCheck( queryInfo.dataStart, queryInfo.dataLength,
						  signatureLength ) );
	signatureData = ( BYTE * ) signature + queryInfo.dataStart;
	signatureDataLength = queryInfo.dataLength;
	zeroise( &queryInfo, sizeof( QUERY_INFO ) );

	/* DLP and ECC signatures are handled somewhat specially */
	if( isDlpAlgo( signAlgo ) || isEccAlgo( signAlgo ) )
		{
		return( checkDlpSignature( signatureData, signatureDataLength, 
								   iSigCheckContext, iHashContext,
								   signatureType ) );
		}

	/* It's a standard signature, process it as normal */
	setMechanismSignInfo( &mechanismInfo, signatureData, signatureDataLength, 
						  iHashContext, iHashContext2, iSigCheckContext );
	status = krnlSendMessage( SYSTEM_OBJECT_HANDLE, IMESSAGE_DEV_SIGCHECK, 
							  &mechanismInfo,
							  ( signatureType == SIGNATURE_SSL ) ? \
								MECHANISM_SIG_SSL : MECHANISM_SIG_PKCS1 );
	clearMechanismInfo( &mechanismInfo );
	if( cryptStatusError( status ) )
		{
		/* The mechanism messages place the acted-on object (in this case the 
		   hash context) first while the higher-level functions place the 
		   signature context next to the signature data, in other words 
		   before the hash context.  Because of this we have to reverse 
		   parameter error values when translating from the mechanism to the 
		   signature function level */
		return( ( status == CRYPT_ARGERROR_NUM1 ) ? \
					CRYPT_ARGERROR_NUM2 : \
				( status == CRYPT_ARGERROR_NUM2 ) ? \
					CRYPT_ARGERROR_NUM1 : status );
		}

	return( CRYPT_OK );
	}