sec_mem.c

cryptlib安全工具包

	MEMLOCK_INFO *memBlockPtr;
	BYTE *memPtr;
#if defined( __BEOS__ )
	area_id areaID;
#endif /* __BEOS__ && BeOS areas */
	int status;

	status = checkInitFree( pointer, &memPtr, &memBlockPtr );
	if( cryptStatusError( status ) )
		return;

	/* Lock the memory list, unlink the new block, and unlock it again */
	MUTEX_LOCK( allocation );
	checkMemCanary( memBlockPtr, memPtr );
	unlinkMemBlock( &krnlData->allocatedListHead, 
					&krnlData->allocatedListTail, memBlockPtr );
	MUTEX_UNLOCK( allocation );

	/* If the memory was locked, unlock it now */
#if defined( __BEOS__ )
	areaID = memBlockPtr->areaID;
	zeroise( memPtr, memBlockPtr->size );
	delete_area( areaID );
#else
	if( memBlockPtr->isLocked )
		munlock( memPtr, memBlockPtr->size );
#endif /* OS-specific memory unlocking */

	/* Zeroise the memory (including the memlock info), free it, and zero
	   the pointer */
#if !defined( __BEOS__ )
	zeroise( memPtr, memBlockPtr->size );
	clFree( "krnlMemFree", memPtr );
#endif /* !__BEOS__ */
	*pointer = NULL;
	}

/****************************************************************************
*																			*
*					ChorusOS Secure Memory Allocation Functions				*
*																			*
****************************************************************************/

#elif defined( __CHORUS__ )

/* ChorusOS is one of the very few embedded OSes with paging capabilities,
   fortunately there's a way to allocate nonpageable memory if paging is
   enabled */

#include <mem/chMem.h>

/* A safe malloc function that performs page locking if possible */

int krnlMemalloc( void **pointer, int size )
	{
	MEMLOCK_INFO *memBlockPtr;
	BYTE *memPtr;
	KnRgnDesc rgnDesc = { K_ANYWHERE, size + MEMLOCK_HEADERSIZE, \
						  K_WRITEABLE | K_NODEMAND };
	int status;

	status = checkInitAlloc( pointer, size );
	if( cryptStatusError( status ) )
		return( status );

	/* Clear return values */
	*pointer = NULL;

	/* Try and allocate the memory */
	adjustMemCanary( size );	/* For canary at end of block */
	if( rgnAllocate( K_MYACTOR, &rgnDesc ) != K_OK )
		return( CRYPT_ERROR_MEMORY );
	memPtr = rgnDesc.startAddr;
	memset( memPtr, 0, size + MEMLOCK_HEADERSIZE );
	memBlockPtr = ( MEMLOCK_INFO * ) memPtr;
	memBlockPtr->isLocked = FALSE;
	memBlockPtr->size = size + MEMLOCK_HEADERSIZE;
	insertMemCanary( memBlockPtr, memPtr );
	*pointer = memPtr + MEMLOCK_HEADERSIZE;

	/* Lock the memory list, insert the new block, and unlock it again */
	MUTEX_LOCK( allocation );
	insertMemBlock( &krnlData->allocatedListHead, 
					&krnlData->allocatedListTail, memBlockPtr );
	MUTEX_UNLOCK( allocation );

	return( CRYPT_OK );
	}

/* A safe free function that scrubs memory and zeroes the pointer.

	"You will softly and suddenly vanish away
	 And never be met with again"	- Lewis Carroll,
									  "The Hunting of the Snark" */

void krnlMemfree( void **pointer )
	{
	MEMLOCK_INFO *memBlockPtr;
	BYTE *memPtr;
	KnRgnDesc rgnDesc = { K_ANYWHERE, 0, 0 };
	int status;

	status = checkInitFree( pointer, &memPtr, &memBlockPtr );
	if( cryptStatusError( status ) )
		return;

	/* Lock the memory list, unlink the new block, and unlock it again */
	MUTEX_LOCK( allocation );
	checkMemCanary( memBlockPtr, memPtr );
	unlinkMemBlock( &krnlData->allocatedListHead, 
					&krnlData->allocatedListTail, memBlockPtr );
	MUTEX_UNLOCK( allocation );

	/* Zeroise the memory (including the memlock info), free it, and zero
	   the pointer */
	rgnDesc.size = memBlockPtr->size;
	rgnDesc.startAddr = memPtr;
	zeroise( memPtr, memBlockPtr->size );
	rgnFree( K_MYACTOR, &rgnDesc );
	*pointer = NULL;
	}

/****************************************************************************
*																			*
*					Macintosh Secure Memory Allocation Functions			*
*																			*
****************************************************************************/

#elif defined( __MAC__ )

#include <Memory.h>

/* A safe malloc function that performs page locking if possible */

int krnlMemalloc( void **pointer, int size )
	{
	MEMLOCK_INFO *memBlockPtr;
	BYTE *memPtr;
	int status;

	status = checkInitAlloc( pointer, size );
	if( cryptStatusError( status ) )
		return( status );

	/* Clear return values */
	*pointer = NULL;

	/* Try and allocate the memory */
	adjustMemCanary( size );	/* For canary at end of block */
	if( ( memPtr = clAlloc( "krnlMemAlloc", \
							size + MEMLOCK_HEADERSIZE ) ) == NULL )
		return( CRYPT_ERROR_MEMORY );
	memset( memPtr, 0, size + MEMLOCK_HEADERSIZE );
	memBlockPtr = ( MEMLOCK_INFO * ) memPtr;
	memBlockPtr->isLocked = FALSE;
	memBlockPtr->size = size + MEMLOCK_HEADERSIZE;
	insertMemCanary( memBlockPtr, memPtr );
	*pointer = memPtr + MEMLOCK_HEADERSIZE;

	/* Try to lock the pages in memory */
#if !defined( CALL_NOT_IN_CARBON ) || CALL_NOT_IN_CARBON
	/* The Mac has two functions for locking memory, HoldMemory() (which
	   makes the memory ineligible for paging) and LockMemory() (which makes
	   it ineligible for paging and also immovable).  We use HoldMemory()
	   since it's slightly more friendly, but really critical applications
	   could use LockMemory() */
	if( HoldMemory( memPtr, memBlockPtr->size ) == noErr )
		memBlockPtr->isLocked = TRUE;
#endif /* Non Mac OS X memory locking */

	/* Lock the memory list, insert the new block, and unlock it again */
	MUTEX_LOCK( allocation );
	insertMemBlock( &krnlData->allocatedListHead, 
					&krnlData->allocatedListTail, memBlockPtr );
	MUTEX_UNLOCK( allocation );

	return( CRYPT_OK );
	}

/* A safe free function that scrubs memory and zeroes the pointer.

	"You will softly and suddenly vanish away
	 And never be met with again"	- Lewis Carroll,
									  "The Hunting of the Snark" */

void krnlMemfree( void **pointer )
	{
	MEMLOCK_INFO *memBlockPtr;
	BYTE *memPtr;
	int status;

	status = checkInitFree( pointer, &memPtr, &memBlockPtr );
	if( cryptStatusError( status ) )
		return;

	/* Lock the memory list, unlink the new block, and unlock it again */
	MUTEX_LOCK( allocation );
	checkMemCanary( memBlockPtr, memPtr );
	unlinkMemBlock( &krnlData->allocatedListHead, 
					&krnlData->allocatedListTail, memBlockPtr );
	MUTEX_UNLOCK( allocation );

	/* If the memory is locked, unlock it now */
#if !defined( CALL_NOT_IN_CARBON ) || CALL_NOT_IN_CARBON
	if( memBlockPtr->isLocked )
		UnholdMemory( memPtr, memBlockPtr->size );
#endif /* Non Mac OS X memory locking */

	/* Zeroise the memory (including the memlock info), free it, and zero
	   the pointer */
	zeroise( memPtr, memBlockPtr->size );
	clFree( "krnlMemFree", memPtr );
	*pointer = NULL;
	}

/****************************************************************************
*																			*
*						Misc.Secure Memory Allocation Functions				*
*																			*
****************************************************************************/

#else

#if defined( __MSDOS__ ) && defined( __DJGPP__ )
  #include <dpmi.h>
  #include <go32.h>
#endif /* DOS-32 */

/* A safe malloc function that performs page locking if possible */

int krnlMemalloc( void **pointer, int size )
	{
	MEMLOCK_INFO *memBlockPtr;
	BYTE *memPtr;
	int status;

	status = checkInitAlloc( pointer, size );
	if( cryptStatusError( status ) )
		return( status );

	/* Clear return values */
	*pointer = NULL;

	/* Try and allocate the memory */
	adjustMemCanary( size );	/* For canary at end of block */
	if( ( memPtr = clAlloc( "krnlMemAlloc", \
							size + MEMLOCK_HEADERSIZE ) ) == NULL )
		return( CRYPT_ERROR_MEMORY );
	memset( memPtr, 0, size + MEMLOCK_HEADERSIZE );
	memBlockPtr = ( MEMLOCK_INFO * ) memPtr;
	memBlockPtr->isLocked = FALSE;
	memBlockPtr->size = size + MEMLOCK_HEADERSIZE;
	insertMemCanary( memBlockPtr, memPtr );
	*pointer = memPtr + MEMLOCK_HEADERSIZE;

	/* If the OS supports paging, try to lock the pages in memory */
#if defined( __MSDOS__ ) && defined( __DJGPP__ )
	/* Under 32-bit MSDOS use the DPMI functions to lock memory */
	if( _go32_dpmi_lock_data( memPtr, memBlockPtr->size ) == 0)
		memBlockPtr->isLocked = TRUE;
#endif /* Systems that support memory locking */

	/* Lock the memory list, insert the new block, and unlock it again */
	MUTEX_LOCK( allocation );
	insertMemBlock( &krnlData->allocatedListHead, 
					&krnlData->allocatedListTail, memBlockPtr );
	MUTEX_UNLOCK( allocation );

	return( CRYPT_OK );
	}

/* A safe free function that scrubs memory and zeroes the pointer.

	"You will softly and suddenly vanish away
	 And never be met with again"	- Lewis Carroll,
									  "The Hunting of the Snark" */

void krnlMemfree( void **pointer )
	{
	MEMLOCK_INFO *memBlockPtr;
	BYTE *memPtr;
	int status;

	status = checkInitFree( pointer, &memPtr, &memBlockPtr );
	if( cryptStatusError( status ) )
		return;

	/* Lock the memory list, unlink the new block, and unlock it again */
	MUTEX_LOCK( allocation );
	checkMemCanary( memBlockPtr, memPtr );
	unlinkMemBlock( &krnlData->allocatedListHead, 
					&krnlData->allocatedListTail, memBlockPtr );
	MUTEX_UNLOCK( allocation );

	/* If the memory is locked, unlock it now */
#if defined( __MSDOS__ ) && defined( __DJGPP__ )
	/* Under 32-bit MSDOS we *could* use the DPMI functions to unlock
	   memory, but as many DPMI hosts implement page locking in a binary
	   form (no lock count maintained), it's better not to unlock anything
	   at all.  Note that this may lead to a shortage of virtual memory in
	   long-running applications */
#endif /* Systems that support memory locking */

	/* Zeroise the memory (including the memlock info), free it, and zero
	   the pointer */
	zeroise( memPtr, memBlockPtr->size );
	clFree( "krnlMemFree", memPtr );
	*pointer = NULL;
	}

#endif /* OS-specific secure memory handling */