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Direktori : /usr/share/perl5/vendor_perl/Archive/Zip/ |
Current File : //usr/share/perl5/vendor_perl/Archive/Zip/ZipFileMember.pm |
package Archive::Zip::ZipFileMember; use strict; use vars qw( $VERSION @ISA ); BEGIN { $VERSION = '1.60'; @ISA = qw ( Archive::Zip::FileMember ); } use Archive::Zip qw( :CONSTANTS :ERROR_CODES :PKZIP_CONSTANTS :UTILITY_METHODS ); # Create a new Archive::Zip::ZipFileMember # given a filename and optional open file handle # sub _newFromZipFile { my $class = shift; my $fh = shift; my $externalFileName = shift; my $possibleEocdOffset = shift; # normally 0 my $self = $class->new( 'crc32' => 0, 'diskNumberStart' => 0, 'localHeaderRelativeOffset' => 0, 'dataOffset' => 0, # localHeaderRelativeOffset + header length @_ ); $self->{'externalFileName'} = $externalFileName; $self->{'fh'} = $fh; $self->{'possibleEocdOffset'} = $possibleEocdOffset; return $self; } sub isDirectory { my $self = shift; return (substr($self->fileName, -1, 1) eq '/' and $self->uncompressedSize == 0); } # Seek to the beginning of the local header, just past the signature. # Verify that the local header signature is in fact correct. # Update the localHeaderRelativeOffset if necessary by adding the possibleEocdOffset. # Returns status. sub _seekToLocalHeader { my $self = shift; my $where = shift; # optional my $previousWhere = shift; # optional $where = $self->localHeaderRelativeOffset() unless defined($where); # avoid loop on certain corrupt files (from Julian Field) return _formatError("corrupt zip file") if defined($previousWhere) && $where == $previousWhere; my $status; my $signature; $status = $self->fh()->seek($where, IO::Seekable::SEEK_SET); return _ioError("seeking to local header") unless $status; ($status, $signature) = _readSignature($self->fh(), $self->externalFileName(), LOCAL_FILE_HEADER_SIGNATURE); return $status if $status == AZ_IO_ERROR; # retry with EOCD offset if any was given. if ($status == AZ_FORMAT_ERROR && $self->{'possibleEocdOffset'}) { $status = $self->_seekToLocalHeader( $self->localHeaderRelativeOffset() + $self->{'possibleEocdOffset'}, $where ); if ($status == AZ_OK) { $self->{'localHeaderRelativeOffset'} += $self->{'possibleEocdOffset'}; $self->{'possibleEocdOffset'} = 0; } } return $status; } # Because I'm going to delete the file handle, read the local file # header if the file handle is seekable. If it is not, I assume that # I've already read the local header. # Return ( $status, $self ) sub _become { my $self = shift; my $newClass = shift; return $self if ref($self) eq $newClass; my $status = AZ_OK; if (_isSeekable($self->fh())) { my $here = $self->fh()->tell(); $status = $self->_seekToLocalHeader(); $status = $self->_readLocalFileHeader() if $status == AZ_OK; $self->fh()->seek($here, IO::Seekable::SEEK_SET); return $status unless $status == AZ_OK; } delete($self->{'eocdCrc32'}); delete($self->{'diskNumberStart'}); delete($self->{'localHeaderRelativeOffset'}); delete($self->{'dataOffset'}); return $self->SUPER::_become($newClass); } sub diskNumberStart { shift->{'diskNumberStart'}; } sub localHeaderRelativeOffset { shift->{'localHeaderRelativeOffset'}; } sub dataOffset { shift->{'dataOffset'}; } # Skip local file header, updating only extra field stuff. # Assumes that fh is positioned before signature. sub _skipLocalFileHeader { my $self = shift; my $header; my $bytesRead = $self->fh()->read($header, LOCAL_FILE_HEADER_LENGTH); if ($bytesRead != LOCAL_FILE_HEADER_LENGTH) { return _ioError("reading local file header"); } my $fileNameLength; my $extraFieldLength; my $bitFlag; ( undef, # $self->{'versionNeededToExtract'}, $bitFlag, undef, # $self->{'compressionMethod'}, undef, # $self->{'lastModFileDateTime'}, undef, # $crc32, undef, # $compressedSize, undef, # $uncompressedSize, $fileNameLength, $extraFieldLength ) = unpack(LOCAL_FILE_HEADER_FORMAT, $header); if ($fileNameLength) { $self->fh()->seek($fileNameLength, IO::Seekable::SEEK_CUR) or return _ioError("skipping local file name"); } if ($extraFieldLength) { $bytesRead = $self->fh()->read($self->{'localExtraField'}, $extraFieldLength); if ($bytesRead != $extraFieldLength) { return _ioError("reading local extra field"); } } $self->{'dataOffset'} = $self->fh()->tell(); if ($bitFlag & GPBF_HAS_DATA_DESCRIPTOR_MASK) { # Read the crc32, compressedSize, and uncompressedSize from the # extended data descriptor, which directly follows the compressed data. # # Skip over the compressed file data (assumes that EOCD compressedSize # was correct) $self->fh()->seek($self->{'compressedSize'}, IO::Seekable::SEEK_CUR) or return _ioError("seeking to extended local header"); # these values should be set correctly from before. my $oldCrc32 = $self->{'eocdCrc32'}; my $oldCompressedSize = $self->{'compressedSize'}; my $oldUncompressedSize = $self->{'uncompressedSize'}; my $status = $self->_readDataDescriptor(); return $status unless $status == AZ_OK; # The buffer withe encrypted data is prefixed with a new # encrypted 12 byte header. The size only changes when # the buffer is also compressed $self->isEncrypted && $oldUncompressedSize > $self->{uncompressedSize} and $oldUncompressedSize -= DATA_DESCRIPTOR_LENGTH; return _formatError( "CRC or size mismatch while skipping data descriptor") if ( $oldCrc32 != $self->{'crc32'} || $oldUncompressedSize != $self->{'uncompressedSize'}); $self->{'crc32'} = 0 if $self->compressionMethod() == COMPRESSION_STORED ; } return AZ_OK; } # Read from a local file header into myself. Returns AZ_OK if successful. # Assumes that fh is positioned after signature. # Note that crc32, compressedSize, and uncompressedSize will be 0 if # GPBF_HAS_DATA_DESCRIPTOR_MASK is set in the bitFlag. sub _readLocalFileHeader { my $self = shift; my $header; my $bytesRead = $self->fh()->read($header, LOCAL_FILE_HEADER_LENGTH); if ($bytesRead != LOCAL_FILE_HEADER_LENGTH) { return _ioError("reading local file header"); } my $fileNameLength; my $crc32; my $compressedSize; my $uncompressedSize; my $extraFieldLength; ( $self->{'versionNeededToExtract'}, $self->{'bitFlag'}, $self->{'compressionMethod'}, $self->{'lastModFileDateTime'}, $crc32, $compressedSize, $uncompressedSize, $fileNameLength, $extraFieldLength ) = unpack(LOCAL_FILE_HEADER_FORMAT, $header); if ($fileNameLength) { my $fileName; $bytesRead = $self->fh()->read($fileName, $fileNameLength); if ($bytesRead != $fileNameLength) { return _ioError("reading local file name"); } $self->fileName($fileName); } if ($extraFieldLength) { $bytesRead = $self->fh()->read($self->{'localExtraField'}, $extraFieldLength); if ($bytesRead != $extraFieldLength) { return _ioError("reading local extra field"); } } $self->{'dataOffset'} = $self->fh()->tell(); if ($self->hasDataDescriptor()) { # Read the crc32, compressedSize, and uncompressedSize from the # extended data descriptor. # Skip over the compressed file data (assumes that EOCD compressedSize # was correct) $self->fh()->seek($self->{'compressedSize'}, IO::Seekable::SEEK_CUR) or return _ioError("seeking to extended local header"); my $status = $self->_readDataDescriptor(); return $status unless $status == AZ_OK; } else { return _formatError( "CRC or size mismatch after reading data descriptor") if ( $self->{'crc32'} != $crc32 || $self->{'uncompressedSize'} != $uncompressedSize); } return AZ_OK; } # This will read the data descriptor, which is after the end of compressed file # data in members that have GPBF_HAS_DATA_DESCRIPTOR_MASK set in their bitFlag. # The only reliable way to find these is to rely on the EOCD compressedSize. # Assumes that file is positioned immediately after the compressed data. # Returns status; sets crc32, compressedSize, and uncompressedSize. sub _readDataDescriptor { my $self = shift; my $signatureData; my $header; my $crc32; my $compressedSize; my $uncompressedSize; my $bytesRead = $self->fh()->read($signatureData, SIGNATURE_LENGTH); return _ioError("reading header signature") if $bytesRead != SIGNATURE_LENGTH; my $signature = unpack(SIGNATURE_FORMAT, $signatureData); # unfortunately, the signature appears to be optional. if ($signature == DATA_DESCRIPTOR_SIGNATURE && ($signature != $self->{'crc32'})) { $bytesRead = $self->fh()->read($header, DATA_DESCRIPTOR_LENGTH); return _ioError("reading data descriptor") if $bytesRead != DATA_DESCRIPTOR_LENGTH; ($crc32, $compressedSize, $uncompressedSize) = unpack(DATA_DESCRIPTOR_FORMAT, $header); } else { $bytesRead = $self->fh()->read($header, DATA_DESCRIPTOR_LENGTH_NO_SIG); return _ioError("reading data descriptor") if $bytesRead != DATA_DESCRIPTOR_LENGTH_NO_SIG; $crc32 = $signature; ($compressedSize, $uncompressedSize) = unpack(DATA_DESCRIPTOR_FORMAT_NO_SIG, $header); } $self->{'eocdCrc32'} = $self->{'crc32'} unless defined($self->{'eocdCrc32'}); $self->{'crc32'} = $crc32; $self->{'compressedSize'} = $compressedSize; $self->{'uncompressedSize'} = $uncompressedSize; return AZ_OK; } # Read a Central Directory header. Return AZ_OK on success. # Assumes that fh is positioned right after the signature. sub _readCentralDirectoryFileHeader { my $self = shift; my $fh = $self->fh(); my $header = ''; my $bytesRead = $fh->read($header, CENTRAL_DIRECTORY_FILE_HEADER_LENGTH); if ($bytesRead != CENTRAL_DIRECTORY_FILE_HEADER_LENGTH) { return _ioError("reading central dir header"); } my ($fileNameLength, $extraFieldLength, $fileCommentLength); ( $self->{'versionMadeBy'}, $self->{'fileAttributeFormat'}, $self->{'versionNeededToExtract'}, $self->{'bitFlag'}, $self->{'compressionMethod'}, $self->{'lastModFileDateTime'}, $self->{'crc32'}, $self->{'compressedSize'}, $self->{'uncompressedSize'}, $fileNameLength, $extraFieldLength, $fileCommentLength, $self->{'diskNumberStart'}, $self->{'internalFileAttributes'}, $self->{'externalFileAttributes'}, $self->{'localHeaderRelativeOffset'} ) = unpack(CENTRAL_DIRECTORY_FILE_HEADER_FORMAT, $header); $self->{'eocdCrc32'} = $self->{'crc32'}; if ($fileNameLength) { $bytesRead = $fh->read($self->{'fileName'}, $fileNameLength); if ($bytesRead != $fileNameLength) { _ioError("reading central dir filename"); } } if ($extraFieldLength) { $bytesRead = $fh->read($self->{'cdExtraField'}, $extraFieldLength); if ($bytesRead != $extraFieldLength) { return _ioError("reading central dir extra field"); } } if ($fileCommentLength) { $bytesRead = $fh->read($self->{'fileComment'}, $fileCommentLength); if ($bytesRead != $fileCommentLength) { return _ioError("reading central dir file comment"); } } # NK 10/21/04: added to avoid problems with manipulated headers if ( $self->{'uncompressedSize'} != $self->{'compressedSize'} and $self->{'compressionMethod'} == COMPRESSION_STORED) { $self->{'uncompressedSize'} = $self->{'compressedSize'}; } $self->desiredCompressionMethod($self->compressionMethod()); return AZ_OK; } sub rewindData { my $self = shift; my $status = $self->SUPER::rewindData(@_); return $status unless $status == AZ_OK; return AZ_IO_ERROR unless $self->fh(); $self->fh()->clearerr(); # Seek to local file header. # The only reason that I'm doing this this way is that the extraField # length seems to be different between the CD header and the LF header. $status = $self->_seekToLocalHeader(); return $status unless $status == AZ_OK; # skip local file header $status = $self->_skipLocalFileHeader(); return $status unless $status == AZ_OK; # Seek to beginning of file data $self->fh()->seek($self->dataOffset(), IO::Seekable::SEEK_SET) or return _ioError("seeking to beginning of file data"); return AZ_OK; } # Return bytes read. Note that first parameter is a ref to a buffer. # my $data; # my ( $bytesRead, $status) = $self->readRawChunk( \$data, $chunkSize ); sub _readRawChunk { my ($self, $dataRef, $chunkSize) = @_; return (0, AZ_OK) unless $chunkSize; my $bytesRead = $self->fh()->read($$dataRef, $chunkSize) or return (0, _ioError("reading data")); return ($bytesRead, AZ_OK); } 1;