file.c

来自「cryptlib安全工具包」· C语言 代码 · 共 2,036 行 · 第 1/5 页

		GetEOF( stream->refNum, &eof ) != noErr )
		return;
	length = eof - position;
	if( length <= 0 )
		return;	/* Nothing to do, exit */
	eraseFile( stream, position, length );
	}

STDC_NONNULL_ARG( ( 1 ) ) \
void fileErase( IN_STRING const char *fileName )
	{
	STREAM stream;
	int length, status;

	assert( fileName != NULL );

	/* Try and open the file so that we can erase it.  If this fails, the
	   best that we can do is a straight unlink */
	status = sFileOpen( &stream, fileName,
						FILE_FLAG_READ | FILE_FLAG_WRITE | \
						FILE_FLAG_EXCLUSIVE_ACCESS );
	if( cryptStatusError( status ) )
		{
		remove( fileName );
		return;
		}

	/* Determine the size of the file and erase it */
	SetFPos( stream.refNum, fsFromStart, 0 );
	GetEOF( stream.refNum, &length );
	eraseFile( stream, position, length );

	/* Delete the file */
	sFileClose( &stream );
	FSpDelete( stream.fsspec );
	}

/* Build the path to a file in the cryptlib directory */

CHECK_RETVAL STDC_NONNULL_ARG( ( 1, 3, 4 ) ) \
int fileBuildCryptlibPath( OUT_BUFFER( pathMaxLen, pathLen ) char *path, 
						   IN_LENGTH_SHORT const int pathMaxLen, 
						   OUT_LENGTH_SHORT_Z int *pathLen,
						   IN_BUFFER( fileNameLen ) const char *fileName, 
						   IN_LENGTH_SHORT const int fileNameLen,
						   IN_ENUM( BUILDPATH_OPTION ) \
						   const BUILDPATH_OPTION_TYPE option )
	{
	assert( isWritePtr( path, pathMaxLen ) );
	assert( isWritePtr( pathLen, sizeof( int ) ) );
	assert( isReadPtr( fileName, fileNameLen ) );

	REQUIRES( pathMaxLen > 8 && pathMaxLen < MAX_INTLENGTH );
	REQUIRES( fileNameLen > 0 && fileNameLen < MAX_INTLENGTH );
	REQUIRES( ( ( option == BUILDPATH_CREATEPATH || \
				  option == BUILDPATH_GETPATH ) && fileName != NULL ) || \
			  ( option == BUILDPATH_RNDSEEDFILE && fileName == NULL ) );

	/* Make sure that the open fails if we can't build the path */
	*path = '\0';

	/* Make sure that the path buffer meets the minimum-length
	   requirements */
	REQUIRES( pathMaxLen >= 64 );

	strlcpy_s( path, pathMaxLen, ":" );

	/* Add the filename to the path */
	return( appendFilename( path, pathMaxLen, pathLen, fileName, 
							fileNameLen, option ) );
	}

/****************************************************************************
*																			*
*							Non-STDIO File Stream Functions					*
*																			*
****************************************************************************/

#elif defined( CONFIG_NO_STDIO )

#if defined( __VMCMS__ ) || defined( __IBM4758__ ) || defined( __TESTIO__ )

/* Some environments place severe restrictions on what can be done with file
   I/O, either having no filesystem at all or having one with characteristics
   that don't fit the stdio model.  For these systems we used our own in-
   memory buffers and make them look like virtual file streams until they're
   flushed, at which point they're written to backing store (flash RAM/
   EEPROM/DASD/whatever non-FS storage is being used) in one go.

   For streams with the sensitive bit set we don't expand the buffer size
   because the original was probably in protected memory, for non-sensitive
   streams we expand the size if necessary.  This means that we have to
   choose a suitably large buffer for sensitive streams (private keys), but
   one that isn't too big.  16K is about right, since typical private key
   files with cert chains are 2K */

#endif /* __VMCMS__ || __IBM4758__ || __TESTIO__ */

/* Open/close a file stream */

CHECK_RETVAL STDC_NONNULL_ARG( ( 1, 2 ) ) \
int sFileOpen( INOUT STREAM *stream, IN_STRING const char *fileName, 
			   IN_FLAGS( FILE ) const int mode )
	{
#ifdef __IBM4758__
	const BOOLEAN useBBRAM = ( mode & FILE_FLAG_SENSITIVE ) ? TRUE : FALSE;
#endif /* __IBM4758__ */
	long length;
	int status;

	assert( isWritePtr( stream, sizeof( STREAM ) ) );
	assert( fileName != NULL );

	REQUIRES( mode != 0 );

	/* Initialise the stream structure as a virtual file stream */
	memset( stream, 0, sizeof( STREAM ) );
	stream->type = STREAM_TYPE_MEMORY;
	stream->flags = STREAM_MFLAG_VFILE;
	if( ( mode & FILE_FLAG_RW_MASK ) == FILE_FLAG_READ )
		stream->flags |= STREAM_FLAG_READONLY;

#if defined( __IBM4758__ )
	/* Make sure that the filename matches the 4758's data item naming
	   conventions and remember the filename.  The best error code to return
	   if there's a problem is a file open error, since this is buried so
	   many levels down that a parameter error won't be meaningful to the
	   caller */
	if( strlen( fileName ) > 8 )
		return( CRYPT_ERROR_OPEN );
	strlcpy_s( stream->name, 8, fileName );

	/* If we're doing a read, fetch the data into memory */
	if( mode & FILE_FLAG_READ )
		{
		/* Find out how big the data item is and allocate a buffer for
		   it */
		status = sccGetPPDLen( ( char * ) fileName, &length );
		if( status != PPDGood )
			{
			return( ( status == PPD_NOT_FOUND ) ? CRYPT_ERROR_NOTFOUND : \
					( status == PPD_NOT_AUTHORIZED ) ? CRYPT_ERROR_PERMISSION : \
					CRYPT_ERROR_OPEN );
			}
		if( ( stream->buffer = clAlloc( "sFileOpen", length ) ) == NULL )
			return( CRYPT_ERROR_MEMORY );
		stream->bufSize = stream->bufEnd = length;
		stream->isIOStream = TRUE;

		/* Fetch the data into the buffer so it can be read as a memory
		   stream */
		status = sccGetPPD( ( char * ) fileName, stream->buffer, length );
		return( ( status != PPDGood ) ? CRYPT_ERROR_READ : CRYPT_OK );
		}

	/* We're doing a write, make sure that there's enough room available.
	   This doesn't guarantee that there'll be enough when the data is
	   committed, but it makes sense to at least check when the "file" is
	   opened */
	status = sccQueryPPDSpace( &length, useBBRAM ? PPD_BBRAM : PPD_FLASH );
	if( status != PPDGood || length < STREAM_VFILE_BUFSIZE )
		return( CRYPT_ERROR_OPEN );

	/* Allocate the initial I/O buffer for the data */
	if( ( stream->buffer = clAlloc( "sFileOpen", 
									STREAM_VFILE_BUFSIZE ) ) == NULL )
		return( CRYPT_ERROR_MEMORY );
	stream->bufSize = STREAM_VFILE_BUFSIZE;
	stream->isSensitive = useBBRAM;

	return( CRYPT_OK );
#elif defined( __VMCMS__ )
	/* If we're going to be doing a write either now or later, we can't open
	   the file until we have all of the data that we want to write to it
	   available since the open arg has to include the file format
	   information, so all we can do at this point is remember the name for
	   later use */
	strlcpy_s( stream->name, MAX_PATH_LENGTH, fileName );
	asciiToEbcdic( stream->name, strlen( stream->name ) );

	/* If we're doing a read, fetch the data into memory */
	if( mode & FILE_FLAG_READ )
		{
		FILE *filePtr;
		fldata_t fileData;
		char fileBuffer[ MAX_PATH_LENGTH + 8 ];
		int allocSize = STREAM_VFILE_BUFSIZE;

		/* Open the file and determine how large it is */
		filePtr = fopen( fileName, "rb" );
		if( filePtr == NULL )
			return( CRYPT_ERROR_OPEN );
		status = fldata( filePtr, fileBuffer, &fileData );
		if( status )
			{
			fclose( filePtr );
			return( CRYPT_ERROR_OPEN );
			}
		length = fileData.__maxreclen;
		if( stream->flags & STREAM_FLAG_READONLY )
			{
			/* If it's a read-only file we only need to allocate a buffer
			   large enough to hold the existing data */
			allocSize = length;
			}

		/* Fetch the data into a buffer large enough to contain the entire
		   stream */
		if( ( stream->buffer = clAlloc( "sFileOpen", allocSize ) ) == NULL )
			return( CRYPT_ERROR_MEMORY );
		stream->bufSize = allocSize;
		stream->bufEnd = length;
		status = fread( stream->buffer, length, 1, filePtr );
		fclose( filePtr );
		if( status != 1 )
			{
			clFree( "sFileOpen", stream->buffer );
			return( CRYPT_ERROR_READ );
			}
		return( CRYPT_OK );
		}

	/* Allocate the initial I/O buffer for the data */
	if( ( stream->buffer = clAlloc( "sFileOpen", 
									STREAM_VFILE_BUFSIZE ) ) == NULL )
		return( CRYPT_ERROR_MEMORY );
	stream->bufSize = STREAM_VFILE_BUFSIZE;

	return( CRYPT_OK );
#elif defined( __TESTIO__ )
	/* Remember the filename.  The __TESTIO__ pseudo-system allows emulation
	   of a non-stdio system for test purposes, so this acts like one that
	   that doesn't have file I/O */
	strlcpy_s( stream->name, MAX_PATH_LENGTH, fileName );

	/* If we're doing a read, fetch the data into memory */
	if( mode & FILE_FLAG_READ )
		{
		FILE *filePtr;
		int allocSize = STREAM_VFILE_BUFSIZE;

		/* Open the file and determine how large it is */
		filePtr = fopen( fileName, "rb" );
		if( filePtr == NULL )
			return( CRYPT_ERROR_OPEN );
		fseek( filePtr, 0L, SEEK_END );
		length = ftell( filePtr );
		fseek( filePtr, 0L, SEEK_SET );
		if( length < 0 )
			{
			fclose( filePtr );
			return( CRYPT_ERROR_OPEN );
			}
		if( stream->flags & STREAM_FLAG_READONLY )
			{
			/* If it's a read-only file we only need to allocate a buffer
			   large enough to hold the existing data */
			allocSize = length;
			}

		/* Fetch the data into a buffer large enough to contain the entire
		   stream */
		if( ( stream->buffer = clAlloc( "sFileOpen", allocSize ) ) == NULL )
			return( CRYPT_ERROR_MEMORY );
		stream->bufSize = allocSize;
		stream->bufEnd = length;
		status = fread( stream->buffer, length, 1, filePtr );
		fclose( filePtr );
		if( status != 1 )
			{
			clFree( "sFileOpen", stream->buffer );
			return( CRYPT_ERROR_READ );
			}
		return( CRYPT_OK );
		}

	/* Allocate the initial I/O buffer for the data */
	if( ( stream->buffer = clAlloc( "sFileOpen", 
									STREAM_VFILE_BUFSIZE ) ) == NULL )
		return( CRYPT_ERROR_MEMORY );
	stream->bufSize = STREAM_VFILE_BUFSIZE;

	return( CRYPT_OK );
#else
	#error Need to add mechanism to connect stream to backing store
	return( CRYPT_ERROR_OPEN );
#endif /* Nonstandard I/O enviroments */
	}

RETVAL STDC_NONNULL_ARG( ( 1 ) ) \
int sFileClose( INOUT STREAM *stream )
	{
	assert( isWritePtr( stream, sizeof( STREAM ) ) );
	
	REQUIRES( stream->type == STREAM_TYPE_FILE );

#if defined( __IBM4758__ )
	/* Close the file and clear the stream structure */
	zeroise( stream->buffer, stream->bufSize );
	clFree( "sFileClose", stream->buffer );
	zeroise( stream, sizeof( STREAM ) );

	return( CRYPT_OK );
#elif defined( __VMCMS__ )
	/* Close the file and clear the stream structure */
	zeroise( stream->buffer, stream->bufSize );
	clFree( "sFileClose", stream->buffer );
	zeroise( stream, sizeof( STREAM ) );

	return( CRYPT_OK );
#elif defined( __TESTIO__ )
	/* Close the file and clear the stream structure */
	zeroise( stream->buffer, stream->bufSize );
	clFree( "sFileClose", stream->buffer );
	zeroise( stream, sizeof( STREAM ) );

	return( CRYPT_OK );
#else
	#error Need to add mechanism to disconnect stream from backing store
	zeroise( stream, sizeof( STREAM ) );

	return( CRYPT_OK );
#endif /* Nonstandard I/O enviroments */
	}

/* Read/write a block of data from/to a file stream */

CHECK_RETVAL STDC_NONNULL_ARG( ( 1, 2, 4 ) ) \
int fileRead( INOUT STREAM *stream, 
			  OUT_BUFFER( length, *bytesRead ) void *buffer, 
			  IN_LENGTH const int length, 
			  OUT_LENGTH_Z int *bytesRead )
	{
	assert( isWritePtr( stream, sizeof( STREAM ) ) );
	assert( isWritePtr( buffer, length ) );
	assert( isWritePtr( bytesRead, sizeof( int ) ) );

	REQUIRES( stream->type == STREAM_TYPE_FILE );
	REQUIRES( length > 0 && length < MAX_INTLENGTH );

	/* Clear return value */
	*bytesRead = 0;

	/* These environments move all data into an in-memory buffer when the
	   file is opened so there's never any need to read more data from the
	   stream */
	retIntError();
	}

CHECK_RETVAL STDC_NONNULL_ARG( ( 1, 2 ) ) \
int fileWrite( INOUT STREAM *stream, 
			   IN_BUFFER( length ) const void *buffer, 
			   IN_LENGTH const int length )
	{
	assert( isWritePtr( stream, sizeof( STREAM ) ) );
	assert( isReadPtr( buffer, length ) );

	REQUIRES( stream->type == STREAM_TYPE_FILE );
	REQUIRES( length > 0 && length < MAX_INTLENGTH );

	/* These environments keep all data in an in-memory buffer that's 
	   committed to backing store when the file is closed so there's never 
	   any need to write data to the stream */
	retIntError();
	}

/* Commit data in a file stream to backing storage */

CHECK_RETVAL STDC_NONNULL_ARG( ( 1 ) ) \
int fileFlush( INOUT STREAM *stream )
	{
#if defined( __IBM4758__ )
	assert( isWritePtr( stream, sizeof( STREAM ) ) );
	
	REQUIRES( stream->type == STREAM_TYPE_FILE );

	/* Write the data to flash or BB memory as appropriate */
	if( sccSavePPD( stream->name, stream->buffer, stream->bufEnd,
			( stream->isSensitive ? PPD_BBRAM : PPD_FLASH ) | PPD_TRIPLE ) != PPDGood )
		return( sSetError( stream, CRYPT_ERROR_WRITE ) );
	return( CRYPT_OK );
#elif defined( __VMCMS__ )
	/* Under CMS, MVS, TSO, etc the only consistent way to handle writes is
	   to write a fixed-length single-record file containing all the data in
	   one record, so we can't really do anything until the data is flushed */
	FILE *filePtr;
	char formatBuffer[ 64 + 8 ];
	int count;

	assert( isWritePtr( stream, sizeof( STREAM ) ) );
	
	REQUIRES( stream->type == STREAM_TYPE_FILE );

	sprintf_s( formatBuffer, 64, "wb, recfm=F, lrecl=%d, noseek", 
			   stream->bufPos );
	filePtr = fopen( stream->name, formatBuffer );
	if( filePtr == NULL )
		return( CRYPT_ERROR_WRITE );
	count = fwrite( stream->buffer, stream->bufEnd, 1, filePtr );
	fclose( filePtr );
	return( ( count != 1 ) ? CRYPT_ERROR_WRITE : CRYPT_OK );
#elif defined( __TESTIO__ )
	FILE *filePtr;
	int count;

	assert( isWritePtr( stream, sizeof( STREAM ) ) );
	
	REQUIRES( stream->type == STREAM_TYPE_FILE );