ObjFW  Artifact [c2a6a4af74]

Artifact c2a6a4af7493b1737e9e9854533f9d2cd51dbb4344d9a3aa5bca570dff937dc6:

• File src/OFData+ASN1DERValue.m — part of check-in [b1944fd052] at 2018-10-27 13:01:38 on branch trunk — Do not subclass OFASN1Value

  The reason for this is that OFASN1Value requires an initializer for DER
  encoding, however, it might be beneficial to create an ASN.1 type
  without providing DER encoding for it. (user: js, size: 6301) [annotate] [blame] [check-ins using]

/*
 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017,
 *               2018
 *   Jonathan Schleifer <js@heap.zone>
 *
 * 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"

#import "OFData+ASN1DERValue.h"
#import "OFASN1BitString.h"
#import "OFASN1Boolean.h"
#import "OFASN1Enumerated.h"
#import "OFASN1IA5String.h"
#import "OFASN1Integer.h"
#import "OFASN1NumericString.h"
#import "OFASN1ObjectIdentifier.h"
#import "OFASN1OctetString.h"
#import "OFASN1PrintableString.h"
#import "OFASN1UTF8String.h"
#import "OFASN1Value.h"
#import "OFArray.h"
#import "OFNull.h"
#import "OFSet.h"

#import "OFInvalidArgumentException.h"
#import "OFInvalidFormatException.h"
#import "OFOutOfRangeException.h"
#import "OFTruncatedDataException.h"

enum {
	ASN1_TAG_CONSTRUCTED_MASK = 0x20
};

int _OFData_ASN1DERValue_reference;

static size_t parseObject(OFData *self, id *object, size_t depthLimit);

static OFArray *
parseSequence(OFData *contents, size_t depthLimit)
{
	OFMutableArray *ret = [OFMutableArray array];
	size_t count = [contents count];

	if (depthLimit == 0)
		@throw [OFOutOfRangeException exception];

	while (count > 0) {
		id object;
		size_t objectLength;

		objectLength = parseObject(contents, &object, depthLimit);

		count -= objectLength;
		contents = [contents subdataWithRange:
		    of_range(objectLength, count)];

		[ret addObject: object];
	}

	[ret makeImmutable];

	return ret;
}

static OFSet *
parseSet(OFData *contents, size_t depthLimit)
{
	OFMutableSet *ret = [OFMutableSet set];
	size_t count = [contents count];
	OFData *previousObjectData = nil;

	if (depthLimit == 0)
		@throw [OFOutOfRangeException exception];

	while (count > 0) {
		id object;
		size_t objectLength;
		OFData *objectData;

		objectLength = parseObject(contents, &object, depthLimit);
		objectData = [contents subdataWithRange:
		    of_range(0, objectLength)];

		if (previousObjectData != nil &&
		    [objectData compare: previousObjectData] !=
		    OF_ORDERED_DESCENDING)
			@throw [OFInvalidFormatException exception];

		count -= objectLength;
		contents = [contents subdataWithRange:
		    of_range(objectLength, count)];

		[ret addObject: object];

		previousObjectData = objectData;
	}

	[ret makeImmutable];

	return ret;
}

static size_t
parseObject(OFData *self, id *object, size_t depthLimit)
{
	const unsigned char *items = [self items];
	size_t count = [self count];
	unsigned char tag;
	size_t contentsLength, bytesConsumed = 0;
	Class valueClass;
	OFData *contents;

	if (count < 2)
		@throw [OFTruncatedDataException exception];

	tag = *items++;
	contentsLength = *items++;
	bytesConsumed += 2;

	if (contentsLength > 127) {
		uint_fast8_t lengthLength = contentsLength & 0x7F;

		if (lengthLength > sizeof(size_t))
			@throw [OFOutOfRangeException exception];

		if (count - bytesConsumed < lengthLength)
			@throw [OFTruncatedDataException exception];

		if (lengthLength == 0 ||
		    (lengthLength == 1 && items[0] < 0x80) ||
		    (lengthLength >= 2 && items[0] == 0))
			@throw [OFInvalidFormatException exception];

		contentsLength = 0;

		for (uint_fast8_t i = 0; i < lengthLength; i++)
			contentsLength = (contentsLength << 8) | *items++;

		bytesConsumed += lengthLength;

		if (contentsLength <= 127)
			@throw [OFInvalidFormatException exception];
	}

	if (count - bytesConsumed < contentsLength)
		@throw [OFTruncatedDataException exception];

	contents = [self subdataWithRange:
	    of_range(bytesConsumed, contentsLength)];
	bytesConsumed += contentsLength;

	switch (tag & ~ASN1_TAG_CONSTRUCTED_MASK) {
	case OF_ASN1_TAG_NUMBER_BOOLEAN:
		valueClass = [OFASN1Boolean class];
		break;
	case OF_ASN1_TAG_NUMBER_INTEGER:
		valueClass = [OFASN1Integer class];
		break;
	case OF_ASN1_TAG_NUMBER_BIT_STRING:
		valueClass = [OFASN1BitString class];
		break;
	case OF_ASN1_TAG_NUMBER_OCTET_STRING:
		valueClass = [OFASN1OctetString class];
		break;
	case OF_ASN1_TAG_NUMBER_NULL:
		if (tag & ASN1_TAG_CONSTRUCTED_MASK)
			@throw [OFInvalidFormatException exception];

		if ([contents count] != 0)
			@throw [OFInvalidFormatException exception];

		*object = [OFNull null];
		return bytesConsumed;
	case OF_ASN1_TAG_NUMBER_OBJECT_IDENTIFIER:
		valueClass = [OFASN1ObjectIdentifier class];
		break;
	case OF_ASN1_TAG_NUMBER_ENUMERATED:
		valueClass = [OFASN1Enumerated class];
		break;
	case OF_ASN1_TAG_NUMBER_UTF8_STRING:
		valueClass = [OFASN1UTF8String class];
		break;
	case OF_ASN1_TAG_NUMBER_SEQUENCE:
		if (!(tag & ASN1_TAG_CONSTRUCTED_MASK))
			@throw [OFInvalidFormatException exception];

		*object = parseSequence(contents, depthLimit - 1);
		return bytesConsumed;
	case OF_ASN1_TAG_NUMBER_SET:
		if (!(tag & ASN1_TAG_CONSTRUCTED_MASK))
			@throw [OFInvalidFormatException exception];

		*object = parseSet(contents, depthLimit - 1);
		return bytesConsumed;
	case OF_ASN1_TAG_NUMBER_NUMERIC_STRING:
		valueClass = [OFASN1NumericString class];
		break;
	case OF_ASN1_TAG_NUMBER_PRINTABLE_STRING:
		valueClass = [OFASN1PrintableString class];
		break;
	case OF_ASN1_TAG_NUMBER_IA5_STRING:
		valueClass = [OFASN1IA5String class];
		break;
	default:
		valueClass = [OFASN1Value class];
		break;
	}

	*object = [[[valueClass alloc]
	      initWithTagClass: tag >> 6
		     tagNumber: tag & 0x1F
		   constructed: tag & ASN1_TAG_CONSTRUCTED_MASK
	    DEREncodedContents: contents] autorelease];
	return bytesConsumed;
}

@implementation OFData (ASN1DERValue)
- (id)ASN1DERValue
{
	return [self ASN1DERValueWithDepthLimit: 32];
}

- (id)ASN1DERValueWithDepthLimit: (size_t)depthLimit
{
	void *pool = objc_autoreleasePoolPush();
	id object;

	if ([self itemSize] != 1)
		@throw [OFInvalidArgumentException exception];

	if (parseObject(self, &object, depthLimit) != [self count])
		@throw [OFInvalidFormatException exception];

	[object retain];

	objc_autoreleasePoolPop(pool);

	return [object autorelease];
}
@end