XADMaster/XADXARParser.m

/*
 * XADXARParser.m
 *
 * Copyright (c) 2017-present, MacPaw Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301  USA
 */
#import "XADXARParser.h"
#import "XADGzipParser.h"
#import "CSZlibHandle.h"
#import "CSBzip2Handle.h"
#import "XADLZMAHandle.h"
#import "XADXZHandle.h"
#import "XADMD5Handle.h"
#import "XADSHA1Handle.h"
#import "XADRegex.h"
#import "NSDateXAD.h"

#define GroundState 0
#define XarState 1
#define TocState 2
#define FileState 3
#define DataState 4
#define ExtendedAttributeState 5
#define OldExtendedAttributeState 6

static const NSString *StringFormat=@"String";
static const NSString *XADStringFormat=@"XADString";
static const NSString *DecimalFormat=@"Decimal";
static const NSString *OctalFormat=@"Octal";
static const NSString *HexFormat=@"Hex";
static const NSString *DateFormat=@"Date";

@implementation XADXARParser

+(int)requiredHeaderSize { return 4; }

+(BOOL)recognizeFileWithHandle:(CSHandle *)handle firstBytes:(NSData *)data name:(NSString *)name
{
	const uint8_t *bytes=[data bytes];
	int length=[data length];

	return length>=4&&bytes[0]=='x'&&bytes[1]=='a'&&bytes[2]=='r'&&bytes[3]=='!';
}

-(void)parse
{
	CSHandle *fh=[self handle];

	[fh skipBytes:4];
	int headsize=[fh readUInt16BE];
	[fh skipBytes:2];
	uint64_t tablecompsize=[fh readUInt64BE];
	uint64_t tableuncompsize=[fh readUInt64BE];

	heapoffset=headsize+tablecompsize;

	filedefinitions=[NSDictionary dictionaryWithObjectsAndKeys:
		[NSArray arrayWithObjects:@"Name",StringFormat,nil],@"name",
		[NSArray arrayWithObjects:@"Type",StringFormat,nil],@"type",
		[NSArray arrayWithObjects:@"Link",StringFormat,nil],@"link",
		[NSArray arrayWithObjects:XADLastModificationDateKey,DateFormat,nil],@"mtime",
		[NSArray arrayWithObjects:XADLastAccessDateKey,DateFormat,nil],@"atime",
		[NSArray arrayWithObjects:XADCreationDateKey,DateFormat,nil],@"ctime",
		[NSArray arrayWithObjects:XADPosixPermissionsKey,OctalFormat,nil],@"mode",
		[NSArray arrayWithObjects:XADPosixUserKey,DecimalFormat,nil],@"uid",
		[NSArray arrayWithObjects:XADPosixGroupKey,DecimalFormat,nil],@"gid",
		[NSArray arrayWithObjects:XADPosixUserNameKey,XADStringFormat,nil],@"user",
		[NSArray arrayWithObjects:XADPosixGroupNameKey,XADStringFormat,nil],@"group",
	nil];

	datadefinitions=[NSDictionary dictionaryWithObjectsAndKeys:
		[NSArray arrayWithObjects:XADFileSizeKey,DecimalFormat,nil],@"size",
		[NSArray arrayWithObjects:XADDataOffsetKey,DecimalFormat,nil],@"offset",
		[NSArray arrayWithObjects:XADDataLengthKey,DecimalFormat,nil],@"length",
		[NSArray arrayWithObjects:@"XARChecksum",HexFormat,nil],@"extracted-checksum",
		[NSArray arrayWithObjects:@"XARChecksumStyle",StringFormat,nil],@"extracted-checksum style",
		[NSArray arrayWithObjects:@"XAREncodingStyle",StringFormat,nil],@"encoding style",
	nil];

	eadefinitions=[NSDictionary dictionaryWithObjectsAndKeys:
		[NSArray arrayWithObjects:@"Name",StringFormat,nil],@"name",
		[NSArray arrayWithObjects:@"Size",DecimalFormat,nil],@"size",
		[NSArray arrayWithObjects:@"Offset",DecimalFormat,nil],@"offset",
		[NSArray arrayWithObjects:@"Length",DecimalFormat,nil],@"length",
		[NSArray arrayWithObjects:@"Checksum",HexFormat,nil],@"extracted-checksum",
		[NSArray arrayWithObjects:@"ChecksumStyle",StringFormat,nil],@"extracted-checksum style",
		[NSArray arrayWithObjects:@"EncodingStyle",StringFormat,nil],@"encoding style",
	nil];

	files=[NSMutableArray array];
	filestack=[NSMutableArray array];

	state=GroundState;

	CSZlibHandle *zh=[CSZlibHandle zlibHandleWithHandle:[fh nonCopiedSubHandleFrom:headsize length:tablecompsize]];
	NSData *data=[zh readDataOfLength:(int)tableuncompsize];

	//NSLog(@"%@",[[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] autorelease]);

	NSXMLParser *xml=[[[NSXMLParser alloc] initWithData:data] autorelease];
	[xml setDelegate:self];
	[xml parse];

	// Check for XIP files, the worst file format ever. This is a cpio file
	// inside a gz file inside a xar, plus a metadata file. The metadata file
	// is currently ignored.
	// The XARDisableXIP boolean property can be used to disable this check.
	NSNumber *disablexip=[[self properties] objectForKey:@"XARDisableXIP"];
	if(!disablexip || ![disablexip boolValue])
	if([files count]==2)
	{
		NSMutableDictionary *first=[files objectAtIndex:0];
		NSMutableDictionary *second=[files objectAtIndex:1];
		NSString *firstname=[first objectForKey:@"Name"];
		NSString *secondname=[second objectForKey:@"Name"];
		NSString *secondstyle=[second objectForKey:@"XAREncodingStyle"];

		if([firstname isEqual:@"Metadata"] &&
		[secondname isEqual:@"Content"] &&
		[secondstyle isEqual:@"application/octet-stream"])
		{
			[second setObject:[NSNumber numberWithBool:YES] forKey:XADIsArchiveKey];
			[second setObject:[NSNumber numberWithBool:YES] forKey:@"XARIsXIP"];
			[self finishFile:second parentPath:[self XADPath]];
			return;
		}
	}

	NSEnumerator *enumerator=[files objectEnumerator];
	NSMutableDictionary *file;
	while((file=[enumerator nextObject]))
	{
		if(![self shouldKeepParsing]) break;
		[self finishFile:file parentPath:[self XADPath]];
	}
}

-(void)finishFile:(NSMutableDictionary *)file parentPath:(XADPath *)parentpath
{
	NSString *name=[file objectForKey:@"Name"];
	NSString *type=[file objectForKey:@"Type"];
	NSString *link=[file objectForKey:@"Link"];
	NSArray *filearray=[file objectForKey:@"Files"];
	NSDictionary *eas=[file objectForKey:@"ExtendedAttributes"];

	[file removeObjectForKey:@"Name"];
	[file removeObjectForKey:@"Type"];
	[file removeObjectForKey:@"Link"];
	[file removeObjectForKey:@"Files"];
	[file removeObjectForKey:@"ExtendedAttributes"];

	XADPath *path=[parentpath pathByAppendingXADStringComponent:[self XADStringWithString:name]];
	[file setObject:path forKey:XADFileNameKey];

	if([type isEqual:@"directory"]||filearray)
	{
		[file setObject:[NSNumber numberWithBool:YES] forKey:XADIsDirectoryKey];
	}
	else if([type isEqual:@"symlink"])
	{
		if(!link) return;
		[file setObject:[self XADStringWithString:link] forKey:XADLinkDestinationKey];
	}

	NSMutableDictionary *eadict=[NSMutableDictionary dictionary];
	NSMutableDictionary *resfork=nil;
	int numeas=0;
	if(eas)
	{
		NSEnumerator *enumerator=[eas objectEnumerator];
		NSMutableDictionary *ea;
		while((ea=[enumerator nextObject]))
		{
			NSString *name=[ea objectForKey:@"Name"];
			if(!name) continue;

			if([name isEqual:@"com.apple.ResourceFork"])
			{
				resfork=ea;
			}
			else
			{
				NSString *encodingstyle=[ea objectForKey:@"EncodingStyle"];
				NSNumber *offset=[ea objectForKey:@"Offset"];
				NSNumber *length=[ea objectForKey:@"Length"];
				NSNumber *size=[ea objectForKey:@"Size"];
				NSData *checksum=[ea objectForKey:@"Checksum"];
				NSString *checksumstyle=[ea objectForKey:@"ChecksumStyle"];

				CSHandle *handle=[self handleForEncodingStyle:encodingstyle
				offset:offset length:length size:size checksum:checksum
				checksumStyle:checksumstyle];

				NSData *data=nil;
				@try { [handle remainingFileContents]; }
				@catch(id e) { NSLog(@"Exception while extracting XAR extended attribute for file %@: %@",path,e); }

				if(data)
				{
					if(![handle hasChecksum] || [handle isChecksumCorrect])
					{
						[eadict setObject:data forKey:name];
						numeas++;
					}
				}
				else
				{
					NSLog(@"Checksum mismatch while extracting extended attribute from XAR file %@",path);
				}
			}
		}

		if(numeas)
		{
			[file setObject:eadict forKey:XADExtendedAttributesKey];
		}
	}

	NSNumber *datalen=[file objectForKey:XADDataLengthKey];
	if(datalen) [file setObject:datalen forKey:XADCompressedSizeKey];
	else [file setObject:[NSNumber numberWithInt:0] forKey:XADCompressedSizeKey];

	if(![file objectForKey:XADFileSizeKey]) [file setObject:[NSNumber numberWithInt:0] forKey:XADFileSizeKey];

	NSString *encodingstyle=[file objectForKey:@"XAREncodingStyle"];
	NSNumber *isxip=[file objectForKey:@"XARIsXIP"];
	XADString *compressionname=[self compressionNameForEncodingStyle:encodingstyle isXIP:isxip && [isxip boolValue]];
	if(compressionname) [file setObject:compressionname forKey:XADCompressionNameKey];

	[self addEntryWithDictionary:file];

	if(resfork)
	{
		NSMutableDictionary *resfile=[NSMutableDictionary dictionaryWithDictionary:file];

		NSNumber *size=[resfork objectForKey:@"Size"];
		NSNumber *offset=[resfork objectForKey:@"Offset"];
		NSNumber *length=[resfork objectForKey:@"Length"];
		NSData *checksum=[resfork objectForKey:@"Checksum"];
		NSString *checksumstyle=[resfork objectForKey:@"ChecksumStyle"];
		NSString *encodingstyle=[resfork objectForKey:@"EncodingStyle"];

		if(size) [resfile setObject:size forKey:XADFileSizeKey];
		if(offset) [resfile setObject:offset forKey:XADDataOffsetKey];
		if(length) [resfile setObject:length forKey:XADDataLengthKey];
		if(length) [resfile setObject:length forKey:XADCompressedSizeKey];
		if(checksum) [resfile setObject:checksum forKey:@"XARChecksum"];
		if(checksumstyle) [resfile setObject:checksumstyle forKey:@"XARChecksumStyle"];
		if(encodingstyle) [resfile setObject:encodingstyle forKey:@"XAREncodingStyle"];

		XADString *compressionname=[self compressionNameForEncodingStyle:encodingstyle isXIP:NO];
		if(compressionname) [resfile setObject:compressionname forKey:XADCompressionNameKey];

		[resfile setObject:[NSNumber numberWithBool:YES] forKey:XADIsResourceForkKey];

		[self addEntryWithDictionary:resfile];
	}

	if(filearray)
	{
		NSEnumerator *enumerator=[filearray objectEnumerator];
		NSMutableDictionary *file;
		while((file=[enumerator nextObject])) [self finishFile:file parentPath:path];
	}
}

-(XADString *)compressionNameForEncodingStyle:(NSString *)encodingstyle isXIP:(BOOL)isxip
{
	NSString *compressionname=nil;

	if(isxip) compressionname=@"Deflate";
	else if(!encodingstyle || [encodingstyle length]==0) compressionname=@"None";
	else if([encodingstyle isEqual:@"application/octet-stream"]) compressionname=@"None";
	else if([encodingstyle isEqual:@"application/x-gzip"]) compressionname=@"Deflate";
	else if([encodingstyle isEqual:@"application/x-bzip2"]) compressionname=@"Bzip2";
	else if([encodingstyle isEqual:@"application/x-xz"]) compressionname=@"LZMA (XZ)";
	else if([encodingstyle isEqual:@"application/x-lzma"]) compressionname=@"LZMA";

	if(compressionname) return [self XADStringWithString:compressionname];
	else return nil;
}

-(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)name
namespaceURI:(NSString *)namespace qualifiedName:(NSString *)qname
attributes:(NSDictionary *)attributes
{
	switch(state)
	{
		case GroundState:
			if([name isEqual:@"xar"]) state=XarState;
		break;

		case XarState:
			if([name isEqual:@"toc"]) state=TocState;
		break;

		case TocState:
			if([name isEqual:@"file"])
			{
				currfile=[NSMutableDictionary dictionary];
				state=FileState;
			}
		break;

		case FileState:
			if([name isEqual:@"file"])
			{
				[filestack addObject:currfile];
				currfile=[NSMutableDictionary dictionary];
				curreas=nil;
				state=FileState;
			}
			else if([name isEqual:@"data"]) state=DataState;
			else if([name isEqual:@"ea"])
			{
				currea=[NSMutableDictionary dictionary];
				state=ExtendedAttributeState;
			}
			else [self startSimpleElement:name attributes:attributes
			definitions:filedefinitions destinationDictionary:currfile];
		break;

		case DataState:
			[self startSimpleElement:name attributes:attributes
			definitions:datadefinitions destinationDictionary:currfile];
		break;

		case ExtendedAttributeState:
			if([name isEqual:@"com.apple.ResourceFork"]||
			[name isEqual:@"com.apple.FinderInfo"])
			{
				currea=[NSMutableDictionary dictionaryWithObject:name forKey:@"Name"];
				state=OldExtendedAttributeState;
			}
			else [self startSimpleElement:name attributes:attributes
			definitions:eadefinitions destinationDictionary:currea];
		break;

		case OldExtendedAttributeState:
			[self startSimpleElement:name attributes:attributes
			definitions:eadefinitions destinationDictionary:currea];
		break;
	}
}

-(void)parser:(NSXMLParser *)parser didEndElement:(NSString *)name
namespaceURI:(NSString *)namespace qualifiedName:(NSString *)qname
{
	switch(state)
	{
		case TocState:
			if([name isEqual:@"toc"]) [parser abortParsing];
		break;

		case FileState:
			if([name isEqual:@"file"])
			{
				if(curreas)
				{
					[currfile setObject:curreas forKey:@"ExtendedAttributes"];
					curreas=nil;
				}

				if([filestack count])
				{
					NSMutableDictionary *parent=[filestack lastObject];
					[filestack removeLastObject];

					NSMutableArray *filearray=[parent objectForKey:@"Files"];
					if(filearray) [filearray addObject:currfile];
					else [parent setObject:[NSMutableArray arrayWithObject:currfile] forKey:@"Files"];

					currfile=parent;
				}
				else
				{
					[files addObject:currfile];
					currfile=nil;
					state=TocState;
				}
			}
			else [self endSimpleElement:name definitions:filedefinitions
			destinationDictionary:currfile];
		break;

		case DataState:
			if([name isEqual:@"data"]) state=FileState;
			else [self endSimpleElement:name definitions:datadefinitions
			destinationDictionary:currfile];
		break;

		case ExtendedAttributeState:
			if([name isEqual:@"ea"])
			{
				if(currea) // Might have been nil'd by OldExtendedAttributeState.
				{
					if(!curreas) curreas=[NSMutableArray array];
					[curreas addObject:currea];
					currea=nil;
				}
				state=FileState;
			}
			else [self endSimpleElement:name definitions:eadefinitions
			destinationDictionary:currea];
		break;

		case OldExtendedAttributeState:
			if([name isEqual:[currea objectForKey:@"Name"]])
			{
				if(!curreas) curreas=[NSMutableArray array];
				[curreas addObject:currea];
				currea=nil;
				state=ExtendedAttributeState;
			}
			else [self endSimpleElement:name definitions:eadefinitions
			destinationDictionary:currea];
		break;
	}
}

-(void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string
{
	[currstring appendString:string];
}

-(void)startSimpleElement:(NSString *)name attributes:(NSDictionary *)attributes
definitions:(NSDictionary *)definitions destinationDictionary:(NSMutableDictionary *)dest
{
	NSEnumerator *enumerator=[attributes keyEnumerator];
	NSString *key;
	while((key=[enumerator nextObject]))
	{
		NSArray *definition=[definitions objectForKey:[NSString stringWithFormat:@"%@ %@",name,key]];
		if(definition) [self parseDefinition:definition string:[attributes objectForKey:key] destinationDictionary:dest];
	}

	NSArray *definition=[definitions objectForKey:name];
	if(definition) currstring=[NSMutableString string];
}

-(void)endSimpleElement:(NSString *)name definitions:(NSDictionary *)definitions
destinationDictionary:(NSMutableDictionary *)dest
{
	if(!currstring) return;

	NSArray *definition=[definitions objectForKey:name];
	[self parseDefinition:definition string:currstring destinationDictionary:dest];

	currstring=nil;
}

-(void)parseDefinition:(NSArray *)definition string:(NSString *)string
destinationDictionary:(NSMutableDictionary *)dest
{
	NSString *key=[definition objectAtIndex:0];
	NSString *format=[definition objectAtIndex:1];

	id obj=nil;
	if(format==StringFormat) obj=string;
	else if(format==XADStringFormat) obj=[self XADStringWithString:string];
	else if(format==DecimalFormat) obj=[NSNumber numberWithLongLong:strtoll([string UTF8String],NULL,10)];
	else if(format==OctalFormat) obj=[NSNumber numberWithLongLong:strtoll([string UTF8String],NULL,8)];
	else if(format==HexFormat)
	{
		NSMutableData *data=[NSMutableData data];
		uint8_t byte;
		int n=0,length=[string length];
		for(int i=0;i<length;i++)
		{
			int c=[string characterAtIndex:i];
			if(isxdigit(c))
			{
				int val=0;
				if(c>='0'&&c<='9') val=c-'0';
				else if(c>='A'&&c<='F') val=c-'A'+10;
				else if(c>='a'&&c<='f') val=c-'a'+10;

				if(n&1) { byte|=val; [data appendBytes:&byte length:1]; }
				else byte=val<<4;

				n++;
			}
		}
		obj=data;
	}
	else if(format==DateFormat)
	{
		NSArray *matches=[string substringsCapturedByPattern:@"^([0-9]{4})-([0-9]{2})-([0-9]{2})T([0-9]{2}):([0-9]{2})(:([0-9]{2})(.([0-9]+))?)?(([+-])([0-9]{2}):([0-9]{2})|Z)$"];
		if(matches)
		{
			int year=[[matches objectAtIndex:1] intValue];
			int month=[[matches objectAtIndex:2] length]?[[matches objectAtIndex:2] intValue]:1;
			int day=[[matches objectAtIndex:3] length]?[[matches objectAtIndex:3] intValue]:1;
			int hour=[[matches objectAtIndex:4] length]?[[matches objectAtIndex:4] intValue]:0;
			int minute=[[matches objectAtIndex:5] length]?[[matches objectAtIndex:5] intValue]:0;
			int second=[[matches objectAtIndex:7] length]?[[matches objectAtIndex:7] intValue]:0;

			int timeoffs=0;
			if([[matches objectAtIndex:11] length])
			{
				timeoffs=[[matches objectAtIndex:12] intValue]*60+[[matches objectAtIndex:13] intValue];
				if([[matches objectAtIndex:11] isEqual:@"-"]) timeoffs=-timeoffs;
			}
			NSTimeZone *tz=[NSTimeZone timeZoneForSecondsFromGMT:timeoffs*60];

			obj=[NSDate XADDateWithYear:year month:month day:day hour:hour minute:minute second:second timeZone:tz];
		}
	}

	if(obj) [dest setObject:obj forKey:key];
}

-(CSHandle *)handleForEntryWithDictionary:(NSDictionary *)dict wantChecksum:(BOOL)checksum
{
	NSData *checksumdata=nil;
	NSString *checksumstyle=nil;
	if(checksum)
	{
		checksumdata=[dict objectForKey:@"XARChecksum"];
		checksumstyle=[dict objectForKey:@"XARChecksumStyle"];
	}

	NSNumber *offset=[dict objectForKey:XADDataOffsetKey];
	NSNumber *length=[dict objectForKey:XADDataLengthKey];
	NSNumber *size=[dict objectForKey:XADFileSizeKey];

	NSNumber *isxip=[dict objectForKey:@"XARIsXIP"];
	if(isxip && [isxip boolValue])
	{
		CSHandle *handle=[[self handle] nonCopiedSubHandleFrom:[offset longLongValue]+heapoffset
		length:[length longLongValue]];

		return [[[XADGzipHandle alloc] initWithHandle:handle] autorelease];
	}
	else
	{
		return [self handleForEncodingStyle:[dict objectForKey:@"XAREncodingStyle"]
		offset:offset length:length size:size checksum:checksumdata checksumStyle:checksumstyle];
	}
}

-(CSHandle *)handleForEncodingStyle:(NSString *)encodingstyle offset:(NSNumber *)offset
length:(NSNumber *)length size:(NSNumber *)size checksum:(NSData *)checksum checksumStyle:(NSString *)checksumstyle
{
	off_t sizeval=[size longLongValue];

	CSHandle *handle;
	if(offset)
	{
		handle=[[self handle] nonCopiedSubHandleFrom:[offset longLongValue]+heapoffset
		length:[length longLongValue]];

		if(!encodingstyle||[encodingstyle length]==0); // no encoding style, copy
		else if([encodingstyle isEqual:@"application/octet-stream"]);  // octe-stream, also copy
		else if([encodingstyle isEqual:@"application/x-gzip"]) handle=[CSZlibHandle zlibHandleWithHandle:handle length:sizeval];
		else if([encodingstyle isEqual:@"application/x-bzip2"]) handle=[CSBzip2Handle bzip2HandleWithHandle:handle length:sizeval];
		else if([encodingstyle isEqual:@"application/x-xz"]) handle=[[[XADXZHandle alloc] initWithHandle:handle length:sizeval] autorelease];
		else if([encodingstyle isEqual:@"application/x-lzma"])
		{
			int first=[handle readUInt8];
			if(first==0xff)
			{
				/*[handle seekToFileOffset:0];
				return [[[XADXZHandle alloc] initWithHandle:handle length:sizeval ...] autorelease];
				*/
				return nil;
			}
			else
			{
				[handle seekToFileOffset:0];
				NSData *props=[handle readDataOfLength:5];
				uint64_t streamsize=[handle readUInt64LE];
				handle=[[[XADLZMAHandle alloc] initWithHandle:handle length:streamsize propertyData:props] autorelease];
			}
		}
		else return nil;
	}
	else
	{
		handle=[self zeroLengthHandleWithChecksum:YES];
	}

	if(checksum&&checksumstyle)
	{
		if([checksumstyle isEqual:@"MD5"])
		{
			return [[[XADMD5Handle alloc] initWithHandle:handle length:sizeval correctDigest:checksum] autorelease];
		}
		else if([checksumstyle isEqual:@"SHA1"])
		{
			return [[[XADSHA1Handle alloc] initWithHandle:handle length:sizeval correctDigest:checksum] autorelease];
		}
	}

	return handle;
}



-(NSString *)formatName { return @"XAR"; }

@end