/*
* 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 "OFASN1Boolean.h"
#import "OFASN1Integer.h"
#import "OFASN1Null.h"
#import "OFASN1UTF8String.h"
#import "OFASN1Value.h"
#import "OFArray.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)
{
size_t count = [contents count];
OFMutableArray *ret;
if (depthLimit == 0)
@throw [OFOutOfRangeException exception];
ret = [OFMutableArray array];
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 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) {
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_NULL:
valueClass = [OFASN1Null class];
break;
case OF_ASN1_TAG_NUMBER_UTF8_STRING:
valueClass = [OFASN1UTF8String class];
break;
case OF_ASN1_TAG_NUMBER_SEQUENCE | ASN1_TAG_CONSTRUCTED_MASK:
*object = parseSequence(contents, depthLimit - 1);
return bytesConsumed;
default:
valueClass = [OFASN1Value class];
break;
}
*object = [valueClass valueWithTagClass: tag >> 6
tagNumber: tag & 0x1F
constructed: tag & ASN1_TAG_CONSTRUCTED_MASK
DEREncodedContents: contents];
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