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#import "XADALZipParser.h"
#import "CSZlibHandle.h"
#import "CSBzip2Handle.h"
#import "XADDeflateHandle.h"
#import "XADCRCHandle.h"
#import "XADRegex.h"
#import "NSDateXAD.h"
static off_t ParseNumber(CSHandle *handle,int size)
{
switch(size)
{
case 1: return [handle readUInt8];
case 2: return [handle readUInt16LE];
case 4: return [handle readUInt32LE];
case 8: return [handle readUInt64LE];
default: [XADException raiseIllegalDataException];
}
return 0;
}
static void CalculateSillyTable(int *table,int param)
{
for(int i=0;i<19;i++) table[i]=i;
for(int i=0;i<19;i++)
{
int swapindex=(i%6)*3+param;
if(swapindex>18) swapindex%=18;
if(swapindex!=i)
{
int tmp=table[i];
table[i]=table[swapindex];
table[swapindex]=tmp;
}
}
}
@implementation XADALZipParser
+(int)requiredHeaderSize { return 8; }
+(BOOL)recognizeFileWithHandle:(CSHandle *)handle firstBytes:(NSData *)data name:(NSString *)name
{
const uint8_t *bytes=[data bytes];
int length=[data length];
return length>=8&&bytes[0]=='A'&&bytes[1]=='L'&&bytes[2]=='Z'&&bytes[3]==1&&bytes[7]==0;
}
+(NSArray *)volumesForHandle:(CSHandle *)handle firstBytes:(NSData *)data name:(NSString *)name
{
NSArray *matches;
if((matches=[name substringsCapturedByPattern:@"^(.*)\\.(alz|a[0-9]{2}|b[0-9]{2})$" options:REG_ICASE]))
{
return [self scanForVolumesWithFilename:name
regex:[XADRegex regexWithPattern:[NSString stringWithFormat:@"^%@\\.(alz|a[0-9]{2}|b[0-9]{2})$",
[[matches objectAtIndex:1] escapedPattern]] options:REG_ICASE]
firstFileExtension:@"alz"];
}
return nil;
}
-(void)parse
{
XADSkipHandle *fh=[self skipHandle];
NSArray *volumes=[self volumes];
if(volumes)
{
int count=[volumes count];
off_t offs=0;
for(int i=0;i<count-1;i++)
{
offs+=[(CSHandle *)[volumes objectAtIndex:i] fileSize];
[fh addSkipFrom:offs-16 to:offs+8];
}
}
[fh skipBytes:8];
while([self shouldKeepParsing])
{
uint32_t signature=[fh readID];
if(signature=='BLZ\001')
{
int namelen=[fh readUInt16LE];
int attrs=[fh readUInt8];
uint32_t dostime=[fh readUInt32LE];
int flags=[fh readUInt8];
[fh skipBytes:1];
NSMutableDictionary *dict=[NSMutableDictionary dictionaryWithObjectsAndKeys:
[NSDate XADDateWithMSDOSDateTime:dostime],XADLastModificationDateKey,
[NSNumber numberWithInt:attrs],@"ALZipAttributes",
[NSNumber numberWithInt:flags],@"ALZipFlags",
nil];
if(attrs&0x10) [dict setObject:[NSNumber numberWithBool:YES] forKey:XADIsDirectoryKey];
if(flags&0x01) [dict setObject:[NSNumber numberWithBool:YES] forKey:XADIsEncryptedKey];
off_t compsize=0;
int sizebytes=flags>>4;
if(sizebytes)
{
int method=[fh readUInt8];
[dict setObject:[NSNumber numberWithInt:method] forKey:@"ALZipCompressionMethod"];
NSString *compname=nil;
switch(method)
{
case 0: compname=@"None"; break;
case 1: compname=@"Bzip2"; break;
case 2: compname=@"Deflate"; break;
case 3: compname=@"Obfuscated deflate"; break;
}
if(compname) [dict setObject:[self XADStringWithString:compname] forKey:XADCompressionNameKey];
[fh skipBytes:1];
[dict setObject:[NSNumber numberWithUnsignedInt:[fh readUInt32LE]] forKey:@"ALZipCRC32"];
compsize=ParseNumber(fh,sizebytes);
off_t size=ParseNumber(fh,sizebytes);
[dict setObject:[NSNumber numberWithLongLong:compsize] forKey:XADCompressedSizeKey];
[dict setObject:[NSNumber numberWithLongLong:compsize] forKey:XADSkipLengthKey];
[dict setObject:[NSNumber numberWithLongLong:size] forKey:XADFileSizeKey];
}
// TODO: force korean encoding?
NSData *namedata=[fh readDataOfLength:namelen];
[dict setObject:[self XADPathWithData:namedata separators:XADEitherPathSeparator] forKey:XADFileNameKey];
[dict setObject:[NSNumber numberWithLongLong:[fh offsetInFile]] forKey:XADSkipOffsetKey];
off_t pos=[fh offsetInFile];
[self addEntryWithDictionary:dict];
[fh seekToFileOffset:pos+compsize];
}
else if(signature=='CLZ\001') break;
else if(signature=='ELZ\001') break; // give up on comment blocks, which are always at the end anyway
else [XADException raiseIllegalDataException];
}
}
-(CSHandle *)handleForEntryWithDictionary:(NSDictionary *)dict wantChecksum:(BOOL)checksum
{
CSHandle *handle=[self handleAtDataOffsetForDictionary:dict];
off_t size=[[dict objectForKey:XADFileSizeKey] longLongValue];
//off_t compsize=[[dict objectForKey:XADCompressedSizeKey] longLongValue];
uint32_t crc=[[dict objectForKey:@"ALZipCRC32"] unsignedIntValue];
if([dict objectForKey:XADIsEncryptedKey])
{
// TODO: encryption
[XADException raiseNotSupportedException];
/*handle=[[[XADZipCryptHandle alloc] initWithHandle:handle length:compsize
password:[self encodedPassword] testByte:crc>>24] autorelease];*/
}
int method=[[dict objectForKey:@"ALZipCompressionMethod"] intValue];
switch(method)
{
case 0: break; // No compression
case 1: handle=[CSBzip2Handle bzip2HandleWithHandle:handle length:size]; break;
case 2: handle=[CSZlibHandle deflateHandleWithHandle:handle length:size]; break;
case 3:
{
handle=[[[XADDeflateHandle alloc] initWithHandle:handle length:size] autorelease];
int order[19];
CalculateSillyTable(order,[[dict objectForKey:XADFileSizeKey] intValue]%16);
[(XADDeflateHandle *)handle setMetaTableOrder:order];
}
break;
default:
[self reportInterestingFileWithReason:@"Unsupported compression method %d",method];
return nil;
}
if(checksum) handle=[XADCRCHandle IEEECRC32HandleWithHandle:handle length:size correctCRC:crc conditioned:YES];
return handle;
}
-(NSString *)formatName { return @"ALZip"; }
@end
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