ObjFW  Artifact [47b9727f66]

Artifact 47b9727f66db0f64339aae36d8f23e0eca6ecefcf2e676e3ca9f061c7e056d7c:

• File src/OFSecureData.m — part of check-in [6ce0093f8d] at 2023-04-10 19:22:32 on branch trunk — Remove OFSerialization

  While the idea sounds nice that the tag name is the class, this means the
  serialization includes whether something is mutable or immutable. This means
  doing as much as making something immutable changes the serialization, which
  can then cause issues after being deserialized. (user: js, size: 14585) [annotate] [blame] [check-ins using] [more...]

/*
 * Copyright (c) 2008-2023 Jonathan Schleifer <js@nil.im>
 *
 * All rights reserved.
 *
 * This file is part of ObjFW. It may be distributed under the terms of the
 * Q Public License 1.0, which can be found in the file LICENSE.QPL included in
 * the packaging of this file.
 *
 * Alternatively, it may be distributed under the terms of the GNU General
 * Public License, either version 2 or 3, which can be found in the file
 * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
 * file.
 */

#include "config.h"

#include <errno.h>
#include <stdlib.h>

#ifdef HAVE_SYS_MMAN_H
# include <sys/mman.h>
#endif

#import "OFSecureData.h"
#import "OFString.h"
#import "OFSystemInfo.h"
#ifdef OF_HAVE_THREADS
# import "OFTLSKey.h"
#endif

#import "OFInitializationFailedException.h"
#import "OFInvalidArgumentException.h"
#import "OFNotImplementedException.h"
#import "OFOutOfMemoryException.h"
#import "OFOutOfRangeException.h"

#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON)
static const size_t chunkSize = 16;

struct Page {
	struct Page *next, *previous;
	void *map;
	unsigned char *page;
};

# if defined(OF_HAVE_COMPILER_TLS)
static thread_local struct Page *firstPage = NULL;
static thread_local struct Page *lastPage = NULL;
static thread_local struct Page **preallocatedPages = NULL;
static thread_local size_t numPreallocatedPages = 0;
# elif defined(OF_HAVE_THREADS)
static OFTLSKey firstPageKey, lastPageKey;
static OFTLSKey preallocatedPagesKey, numPreallocatedPagesKey;
# else
static struct Page *firstPage = NULL;
static struct Page *lastPage = NULL;
static struct Page **preallocatedPages = NULL;
static size_t numPreallocatedPages = 0;
# endif

static void *
mapPages(size_t numPages)
{
	size_t pageSize = [OFSystemInfo pageSize];
	void *pointer;

	if (numPages > SIZE_MAX / pageSize)
		@throw [OFOutOfRangeException exception];

	if ((pointer = mmap(NULL, numPages * pageSize, PROT_READ | PROT_WRITE,
	    MAP_PRIVATE | MAP_ANON, -1, 0)) == MAP_FAILED)
		@throw [OFOutOfMemoryException
		    exceptionWithRequestedSize: numPages * pageSize];

	if (mlock(pointer, numPages * pageSize) != 0) {
		munmap(pointer, numPages * pageSize);
		@throw [OFOutOfMemoryException
		    exceptionWithRequestedSize: numPages * pageSize];
	}

	return pointer;
}

static void
unmapPages(void *pointer, size_t numPages)
{
	size_t pageSize = [OFSystemInfo pageSize];

	if (numPages > SIZE_MAX / pageSize)
		@throw [OFOutOfRangeException exception];

	munlock(pointer, numPages * pageSize);
	munmap(pointer, numPages * pageSize);
}

static struct Page *
addPage(bool allowPreallocated)
{
	size_t pageSize = [OFSystemInfo pageSize];
	size_t mapSize = OFRoundUpToPowerOf2(CHAR_BIT, pageSize / chunkSize) /
	    CHAR_BIT;
	struct Page *page;
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
	struct Page *lastPage;
# endif

	if (allowPreallocated) {
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
		uintptr_t numPreallocatedPages =
		    (uintptr_t)OFTLSKeyGet(numPreallocatedPagesKey);
# endif

		if (numPreallocatedPages > 0) {
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
			struct Page **preallocatedPages =
			    OFTLSKeyGet(preallocatedPagesKey);
# endif

			numPreallocatedPages--;
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
			OFEnsure(OFTLSKeySet(numPreallocatedPagesKey,
			    (void *)numPreallocatedPages) == 0);
# endif

			page = preallocatedPages[numPreallocatedPages];

			if (numPreallocatedPages == 0) {
				OFFreeMemory(preallocatedPages);
				preallocatedPages = NULL;
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
				OFEnsure(OFTLSKeySet(preallocatedPagesKey,
				    preallocatedPages) == 0);
# endif
			}

			return page;
		}
	}

	page = OFAllocMemory(1, sizeof(*page));
	@try {
		page->map = OFAllocZeroedMemory(1, mapSize);
	} @catch (id e) {
		OFFreeMemory(page);
		@throw e;
	}
	@try {
		page->page = mapPages(1);
	} @catch (id e) {
		OFFreeMemory(page->map);
		OFFreeMemory(page);
		@throw e;
	}
	OFZeroMemory(page->page, pageSize);

# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
	lastPage = OFTLSKeyGet(lastPageKey);
# endif

	page->previous = lastPage;
	page->next = NULL;

	if (lastPage != NULL)
		lastPage->next = page;

# if defined(OF_HAVE_COMPILER_TLS) || !defined(OF_HAVE_THREADS)
	lastPage = page;

	if (firstPage == NULL)
		firstPage = page;
# else
	OFEnsure(OFTLSKeySet(lastPageKey, page) == 0);

	if (OFTLSKeyGet(firstPageKey) == NULL)
		OFEnsure(OFTLSKeySet(firstPageKey, page) == 0);
# endif

	return page;
}

static void
removePageIfEmpty(struct Page *page)
{
	unsigned char *map = page->map;
	size_t pageSize = [OFSystemInfo pageSize];
	size_t mapSize = OFRoundUpToPowerOf2(CHAR_BIT, pageSize / chunkSize) /
	    CHAR_BIT;

	for (size_t i = 0; i < mapSize; i++)
		if (map[i] != 0)
			return;

	unmapPages(page->page, 1);
	OFFreeMemory(page->map);

	if (page->previous != NULL)
		page->previous->next = page->next;
	if (page->next != NULL)
		page->next->previous = page->previous;

# if defined(OF_HAVE_COMPILER_TLS) || !defined(OF_HAVE_THREADS)
	if (firstPage == page)
		firstPage = page->next;
	if (lastPage == page)
		lastPage = page->previous;
# else
	if (OFTLSKeyGet(firstPageKey) == page)
		OFEnsure(OFTLSKeySet(firstPageKey, page->next) == 0);
	if (OFTLSKeyGet(lastPageKey) == page)
		OFEnsure(OFTLSKeySet(lastPageKey, page->previous) == 0);
# endif

	OFFreeMemory(page);
}

static void *
allocateMemory(struct Page *page, size_t bytes)
{
	size_t chunks, chunksLeft, pageSize, i, firstChunk;

	bytes = OFRoundUpToPowerOf2(chunkSize, bytes);
	chunks = chunksLeft = bytes / chunkSize;
	firstChunk = 0;
	pageSize = [OFSystemInfo pageSize];

	for (i = 0; i < pageSize / chunkSize; i++) {
		if (OFBitsetIsSet(page->map, i)) {
			chunksLeft = chunks;
			firstChunk = i + 1;
			continue;
		}

		if (--chunksLeft == 0)
			break;
	}

	if (chunksLeft == 0) {
		for (size_t j = firstChunk; j < firstChunk + chunks; j++)
			OFBitsetSet(page->map, j);

		return page->page + (chunkSize * firstChunk);
	}

	return NULL;
}

static void
freeMemory(struct Page *page, void *pointer, size_t bytes)
{
	size_t chunks, chunkIndex;

	bytes = OFRoundUpToPowerOf2(chunkSize, bytes);
	chunks = bytes / chunkSize;
	chunkIndex = ((uintptr_t)pointer - (uintptr_t)page->page) / chunkSize;

	OFZeroMemory(pointer, bytes);

	for (size_t i = 0; i < chunks; i++)
		OFBitsetClear(page->map, chunkIndex + i);
}
#endif

@implementation OFSecureData
@synthesize allowsSwappableMemory = _allowsSwappableMemory;

#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON) && \
    !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
+ (void)initialize
{
	if (self != [OFSecureData class])
		return;

	if (OFTLSKeyNew(&firstPageKey) != 0 || OFTLSKeyNew(&lastPageKey) != 0 ||
	    OFTLSKeyNew(&preallocatedPagesKey) != 0 ||
	    OFTLSKeyNew(&numPreallocatedPagesKey) != 0)
		@throw [OFInitializationFailedException
		    exceptionWithClass: self];
}
#endif

+ (void)preallocateUnswappableMemoryWithSize: (size_t)size
{
#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON)
	size_t pageSize = [OFSystemInfo pageSize];
	size_t numPages = OFRoundUpToPowerOf2(pageSize, size) / pageSize;
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
	struct Page **preallocatedPages = OFTLSKeyGet(preallocatedPagesKey);
	size_t numPreallocatedPages;
# endif
	size_t i;

	if (preallocatedPages != NULL)
		@throw [OFInvalidArgumentException exception];

	preallocatedPages = OFAllocZeroedMemory(numPages, sizeof(struct Page));
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
	OFEnsure(OFTLSKeySet(preallocatedPagesKey, preallocatedPages) == 0);
# endif

	@try {
		for (i = 0; i < numPages; i++)
			preallocatedPages[i] = addPage(false);
	} @catch (id e) {
		for (size_t j = 0; j < i; j++)
			removePageIfEmpty(preallocatedPages[j]);

		OFFreeMemory(preallocatedPages);
		preallocatedPages = NULL;

		@throw e;
	}

	numPreallocatedPages = numPages;
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
	OFEnsure(OFTLSKeySet(numPreallocatedPagesKey,
	    (void *)(uintptr_t)numPreallocatedPages) == 0);
# endif
#else
	@throw [OFNotImplementedException exceptionWithSelector: _cmd
							 object: self];
#endif
}

+ (instancetype)dataWithCount: (size_t)count
	allowsSwappableMemory: (bool)allowsSwappableMemory
{
	return [[[self alloc] initWithCount: count
		      allowsSwappableMemory: allowsSwappableMemory]
	    autorelease];
}

+ (instancetype)dataWithCount: (size_t)count
		     itemSize: (size_t)itemSize
	allowsSwappableMemory: (bool)allowsSwappableMemory
{
	return [[[self alloc] initWithCount: count
				   itemSize: itemSize
		      allowsSwappableMemory: allowsSwappableMemory]
	    autorelease];
}

+ (instancetype)dataWithItems: (const void *)items
			count: (size_t)count
{
	OF_UNRECOGNIZED_SELECTOR
}

+ (instancetype)dataWithItems: (const void *)items
			count: (size_t)count
		     itemSize: (size_t)itemSize
{
	OF_UNRECOGNIZED_SELECTOR
}

+ (instancetype)dataWithItemsNoCopy: (void *)items
			      count: (size_t)count
		       freeWhenDone: (bool)freeWhenDone
{
	OF_UNRECOGNIZED_SELECTOR
}

+ (instancetype)dataWithItemsNoCopy: (void *)items
			      count: (size_t)count
			   itemSize: (size_t)itemSize
		       freeWhenDone: (bool)freeWhenDone
{
	OF_UNRECOGNIZED_SELECTOR
}

#ifdef OF_HAVE_FILES
+ (instancetype)dataWithContentsOfFile: (OFString *)path
{
	OF_UNRECOGNIZED_SELECTOR
}
#endif

+ (instancetype)dataWithContentsOfIRI: (OFIRI *)IRI
{
	OF_UNRECOGNIZED_SELECTOR
}

+ (instancetype)dataWithStringRepresentation: (OFString *)string
{
	OF_UNRECOGNIZED_SELECTOR
}

+ (instancetype)dataWithBase64EncodedString: (OFString *)string
{
	OF_UNRECOGNIZED_SELECTOR
}


- (instancetype)initWithCount: (size_t)count
	allowsSwappableMemory: (bool)allowsSwappableMemory
{
	return [self initWithCount: count
			  itemSize: 1
	     allowsSwappableMemory: allowsSwappableMemory];
}

- (instancetype)initWithCount: (size_t)count
		     itemSize: (size_t)itemSize
	allowsSwappableMemory: (bool)allowsSwappableMemory
{
	self = [super init];

	@try {
#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON)
		size_t pageSize = [OFSystemInfo pageSize];
#endif

		if (count > SIZE_MAX / itemSize)
			@throw [OFOutOfRangeException exception];

		if (allowsSwappableMemory) {
			_items = OFAllocMemory(count, itemSize);
			_freeWhenDone = true;
			memset(_items, 0, count * itemSize);
#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON)
		} else if (count * itemSize >= pageSize)
			_items = mapPages(OFRoundUpToPowerOf2(pageSize,
			    count * itemSize) / pageSize);
		else {
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
			struct Page *lastPage = OFTLSKeyGet(lastPageKey);
# endif

			for (struct Page *page = lastPage; page != NULL;
			    page = page->previous) {
				_items = allocateMemory(page, count * itemSize);

				if (_items != NULL) {
					_page = page;
					break;
				}
			}

			if (_items == NULL) {
				_page = addPage(true);
				_items = allocateMemory(_page,
				    count * itemSize);

				if (_items == NULL)
					@throw [OFOutOfMemoryException
					    exceptionWithRequestedSize:
					    count * itemSize];
			}
		}
#else
		} else
			@throw [OFNotImplementedException
			    exceptionWithSelector: _cmd
					   object: nil];
#endif

		_count = count;
		_itemSize = itemSize;
		_allowsSwappableMemory = allowsSwappableMemory;
	} @catch (id e) {
		[self release];
		@throw e;
	}

	return self;
}

- (instancetype)initWithItems: (const void *)items count: (size_t)count
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)initWithItems: (const void *)items
			count: (size_t)count
		     itemSize: (size_t)itemSize
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)initWithItemsNoCopy: (void *)items
			      count: (size_t)count
		       freeWhenDone: (bool)freeWhenDone
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)initWithItemsNoCopy: (void *)items
			      count: (size_t)count
			   itemSize: (size_t)itemSize
		       freeWhenDone: (bool)freeWhenDone
{
	OF_INVALID_INIT_METHOD
}

#ifdef OF_HAVE_FILES
- (instancetype)initWithContentsOfFile: (OFString *)path
{
	OF_INVALID_INIT_METHOD
}
#endif

- (instancetype)initWithContentsOfIRI: (OFIRI *)IRI
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)initWithStringRepresentation: (OFString *)string
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)initWithBase64EncodedString: (OFString *)string
{
	OF_INVALID_INIT_METHOD
}

- (void)dealloc
{
	[self zero];

#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON)
	if (!_allowsSwappableMemory) {
		size_t pageSize = [OFSystemInfo pageSize];

		if (_count * _itemSize > pageSize)
			unmapPages(_items,
			    OFRoundUpToPowerOf2(pageSize, _count * _itemSize) /
			    pageSize);
		else if (_page != NULL) {
			if (_items != NULL)
				freeMemory(_page, _items, _count * _itemSize);

			removePageIfEmpty(_page);
		}
	}
#endif

	[super dealloc];
}

- (void *)mutableItems
{
	return _items;
}

- (void *)mutableItemAtIndex: (size_t)idx
{
	if (idx >= _count)
		@throw [OFOutOfRangeException exception];

	return _items + idx * _itemSize;
}

- (void)zero
{
	OFZeroMemory(_items, _count * _itemSize);
}

- (id)copy
{
	OFSecureData *copy = [[OFSecureData alloc]
		    initWithCount: _count
			 itemSize: _itemSize
	    allowsSwappableMemory: _allowsSwappableMemory];

	memcpy(copy.mutableItems, _items, _count * _itemSize);

	return copy;
}

- (id)mutableCopy
{
	OFSecureData *copy = [[OFSecureData alloc]
		    initWithCount: _count
			 itemSize: _itemSize
	    allowsSwappableMemory: _allowsSwappableMemory];

	memcpy(copy.mutableItems, _items, _count * _itemSize);

	return copy;
}

- (bool)isEqual: (id)object
{
	OFData *otherData;
	unsigned char diff;

	if (object == self)
		return true;

	if (![object isKindOfClass: [OFData class]])
		return false;

	otherData = object;

	if (otherData->_count != _count || otherData->_itemSize != _itemSize)
		return false;

	diff = 0;

	for (size_t i = 0; i < _count * _itemSize; i++)
		diff |= otherData->_items[i] ^ _items[i];

	return (diff == 0);
}

- (OFString *)description
{
	return @"<OFSecureData>";
}

- (OFString *)stringRepresentation
{
	OF_UNRECOGNIZED_SELECTOR
}

- (OFString *)stringByBase64Encoding
{
	OF_UNRECOGNIZED_SELECTOR
}

#ifdef OF_HAVE_FILES
- (void)writeToFile: (OFString *)path
{
	OF_UNRECOGNIZED_SELECTOR
}
#endif

- (void)writeToIRI: (OFIRI *)IRI
{
	OF_UNRECOGNIZED_SELECTOR
}

- (OFData *)messagePackRepresentation
{
	OF_UNRECOGNIZED_SELECTOR
}
@end