zipfile.py
| 58.1 KB | Satir:
0
| py
Geri
""" Read and write ZIP files. """ import struct, os, time, sys, shutil import binascii, cStringIO, stat import io import re import string try: import zlib # We may need its compression method crc32 = zlib.crc32 except ImportError: zlib = None crc32 = binascii.crc32 __all__ = ["BadZipfile", "error", "ZIP_STORED", "ZIP_DEFLATED", "is_zipfile", "ZipInfo", "ZipFile", "PyZipFile", "LargeZipFile" ] class BadZipfile(Exception): pass class LargeZipFile(Exception): """ Raised when writing a zipfile, the zipfile requires ZIP64 extensions and those extensions are disabled. """ error = BadZipfile # The exception raised by this module ZIP64_LIMIT = (1 << 31) - 1 ZIP_FILECOUNT_LIMIT = (1 << 16) - 1 ZIP_MAX_COMMENT = (1 << 16) - 1 # constants for Zip file compression methods ZIP_STORED = 0 ZIP_DEFLATED = 8 # Other ZIP compression methods not supported # Below are some formats and associated data for reading/writing headers using # the struct module. The names and structures of headers/records are those used # in the PKWARE description of the ZIP file format: # http://www.pkware.com/documents/casestudies/APPNOTE.TXT # (URL valid as of January 2008) # The "end of central directory" structure, magic number, size, and indices # (section V.I in the format document) structEndArchive = "<4s4H2LH" stringEndArchive = "PK\005\006" sizeEndCentDir = struct.calcsize(structEndArchive) _ECD_SIGNATURE = 0 _ECD_DISK_NUMBER = 1 _ECD_DISK_START = 2 _ECD_ENTRIES_THIS_DISK = 3 _ECD_ENTRIES_TOTAL = 4 _ECD_SIZE = 5 _ECD_OFFSET = 6 _ECD_COMMENT_SIZE = 7 # These last two indices are not part of the structure as defined in the # spec, but they are used internally by this module as a convenience _ECD_COMMENT = 8 _ECD_LOCATION = 9 # The "central directory" structure, magic number, size, and indices # of entries in the structure (section V.F in the format document) structCentralDir = "<4s4B4HL2L5H2L" stringCentralDir = "PK\001\002" sizeCentralDir = struct.calcsize(structCentralDir) # indexes of entries in the central directory structure _CD_SIGNATURE = 0 _CD_CREATE_VERSION = 1 _CD_CREATE_SYSTEM = 2 _CD_EXTRACT_VERSION = 3 _CD_EXTRACT_SYSTEM = 4 _CD_FLAG_BITS = 5 _CD_COMPRESS_TYPE = 6 _CD_TIME = 7 _CD_DATE = 8 _CD_CRC = 9 _CD_COMPRESSED_SIZE = 10 _CD_UNCOMPRESSED_SIZE = 11 _CD_FILENAME_LENGTH = 12 _CD_EXTRA_FIELD_LENGTH = 13 _CD_COMMENT_LENGTH = 14 _CD_DISK_NUMBER_START = 15 _CD_INTERNAL_FILE_ATTRIBUTES = 16 _CD_EXTERNAL_FILE_ATTRIBUTES = 17 _CD_LOCAL_HEADER_OFFSET = 18 # The "local file header" structure, magic number, size, and indices # (section V.A in the format document) structFileHeader = "<4s2B4HL2L2H" stringFileHeader = "PK\003\004" sizeFileHeader = struct.calcsize(structFileHeader) _FH_SIGNATURE = 0 _FH_EXTRACT_VERSION = 1 _FH_EXTRACT_SYSTEM = 2 _FH_GENERAL_PURPOSE_FLAG_BITS = 3 _FH_COMPRESSION_METHOD = 4 _FH_LAST_MOD_TIME = 5 _FH_LAST_MOD_DATE = 6 _FH_CRC = 7 _FH_COMPRESSED_SIZE = 8 _FH_UNCOMPRESSED_SIZE = 9 _FH_FILENAME_LENGTH = 10 _FH_EXTRA_FIELD_LENGTH = 11 # The "Zip64 end of central directory locator" structure, magic number, and size structEndArchive64Locator = "<4sLQL" stringEndArchive64Locator = "PK\x06\x07" sizeEndCentDir64Locator = struct.calcsize(structEndArchive64Locator) # The "Zip64 end of central directory" record, magic number, size, and indices # (section V.G in the format document) structEndArchive64 = "<4sQ2H2L4Q" stringEndArchive64 = "PK\x06\x06" sizeEndCentDir64 = struct.calcsize(structEndArchive64) _CD64_SIGNATURE = 0 _CD64_DIRECTORY_RECSIZE = 1 _CD64_CREATE_VERSION = 2 _CD64_EXTRACT_VERSION = 3 _CD64_DISK_NUMBER = 4 _CD64_DISK_NUMBER_START = 5 _CD64_NUMBER_ENTRIES_THIS_DISK = 6 _CD64_NUMBER_ENTRIES_TOTAL = 7 _CD64_DIRECTORY_SIZE = 8 _CD64_OFFSET_START_CENTDIR = 9 _DD_SIGNATURE = 0x08074b50 _EXTRA_FIELD_STRUCT = struct.Struct('<HH') def _strip_extra(extra, xids): # Remove Extra Fields with specified IDs. unpack = _EXTRA_FIELD_STRUCT.unpack modified = False buffer = [] start = i = 0 while i + 4 <= len(extra): xid, xlen = unpack(extra[i : i + 4]) j = i + 4 + xlen if xid in xids: if i != start: buffer.append(extra[start : i]) start = j modified = True i = j if not modified: return extra return b''.join(buffer) def _check_zipfile(fp): try: if _EndRecData(fp): return True # file has correct magic number except IOError: pass return False def is_zipfile(filename): """Quickly see if a file is a ZIP file by checking the magic number. The filename argument may be a file or file-like object too. """ result = False try: if hasattr(filename, "read"): result = _check_zipfile(fp=filename) else: with open(filename, "rb") as fp: result = _check_zipfile(fp) except IOError: pass return result def _EndRecData64(fpin, offset, endrec): """ Read the ZIP64 end-of-archive records and use that to update endrec """ try: fpin.seek(offset - sizeEndCentDir64Locator, 2) except IOError: # If the seek fails, the file is not large enough to contain a ZIP64 # end-of-archive record, so just return the end record we were given. return endrec data = fpin.read(sizeEndCentDir64Locator) if len(data) != sizeEndCentDir64Locator: return endrec sig, diskno, reloff, disks = struct.unpack(structEndArchive64Locator, data) if sig != stringEndArchive64Locator: return endrec if diskno != 0 or disks != 1: raise BadZipfile("zipfiles that span multiple disks are not supported") # Assume no 'zip64 extensible data' fpin.seek(offset - sizeEndCentDir64Locator - sizeEndCentDir64, 2) data = fpin.read(sizeEndCentDir64) if len(data) != sizeEndCentDir64: return endrec sig, sz, create_version, read_version, disk_num, disk_dir, \ dircount, dircount2, dirsize, diroffset = \ struct.unpack(structEndArchive64, data) if sig != stringEndArchive64: return endrec # Update the original endrec using data from the ZIP64 record endrec[_ECD_SIGNATURE] = sig endrec[_ECD_DISK_NUMBER] = disk_num endrec[_ECD_DISK_START] = disk_dir endrec[_ECD_ENTRIES_THIS_DISK] = dircount endrec[_ECD_ENTRIES_TOTAL] = dircount2 endrec[_ECD_SIZE] = dirsize endrec[_ECD_OFFSET] = diroffset return endrec def _EndRecData(fpin): """Return data from the "End of Central Directory" record, or None. The data is a list of the nine items in the ZIP "End of central dir" record followed by a tenth item, the file seek offset of this record.""" # Determine file size fpin.seek(0, 2) filesize = fpin.tell() # Check to see if this is ZIP file with no archive comment (the # "end of central directory" structure should be the last item in the # file if this is the case). try: fpin.seek(-sizeEndCentDir, 2) except IOError: return None data = fpin.read() if (len(data) == sizeEndCentDir and data[0:4] == stringEndArchive and data[-2:] == b"\000\000"): # the signature is correct and there's no comment, unpack structure endrec = struct.unpack(structEndArchive, data) endrec=list(endrec) # Append a blank comment and record start offset endrec.append("") endrec.append(filesize - sizeEndCentDir) # Try to read the "Zip64 end of central directory" structure return _EndRecData64(fpin, -sizeEndCentDir, endrec) # Either this is not a ZIP file, or it is a ZIP file with an archive # comment. Search the end of the file for the "end of central directory" # record signature. The comment is the last item in the ZIP file and may be # up to 64K long. It is assumed that the "end of central directory" magic # number does not appear in the comment. maxCommentStart = max(filesize - (1 << 16) - sizeEndCentDir, 0) fpin.seek(maxCommentStart, 0) data = fpin.read() start = data.rfind(stringEndArchive) if start >= 0: # found the magic number; attempt to unpack and interpret recData = data[start:start+sizeEndCentDir] if len(recData) != sizeEndCentDir: # Zip file is corrupted. return None endrec = list(struct.unpack(structEndArchive, recData)) commentSize = endrec[_ECD_COMMENT_SIZE] #as claimed by the zip file comment = data[start+sizeEndCentDir:start+sizeEndCentDir+commentSize] endrec.append(comment) endrec.append(maxCommentStart + start) # Try to read the "Zip64 end of central directory" structure return _EndRecData64(fpin, maxCommentStart + start - filesize, endrec) # Unable to find a valid end of central directory structure return None class ZipInfo (object): """Class with attributes describing each file in the ZIP archive.""" __slots__ = ( 'orig_filename', 'filename', 'date_time', 'compress_type', 'comment', 'extra', 'create_system', 'create_version', 'extract_version', 'reserved', 'flag_bits', 'volume', 'internal_attr', 'external_attr', 'header_offset', 'CRC', 'compress_size', 'file_size', '_raw_time', ) def __init__(self, filename="NoName", date_time=(1980,1,1,0,0,0)): self.orig_filename = filename # Original file name in archive # Terminate the file name at the first null byte. Null bytes in file # names are used as tricks by viruses in archives. null_byte = filename.find(chr(0)) if null_byte >= 0: filename = filename[0:null_byte] # This is used to ensure paths in generated ZIP files always use # forward slashes as the directory separator, as required by the # ZIP format specification. if os.sep != "/" and os.sep in filename: filename = filename.replace(os.sep, "/") self.filename = filename # Normalized file name self.date_time = date_time # year, month, day, hour, min, sec if date_time[0] < 1980: raise ValueError('ZIP does not support timestamps before 1980') # Standard values: self.compress_type = ZIP_STORED # Type of compression for the file self.comment = "" # Comment for each file self.extra = "" # ZIP extra data if sys.platform == 'win32': self.create_system = 0 # System which created ZIP archive else: # Assume everything else is unix-y self.create_system = 3 # System which created ZIP archive self.create_version = 20 # Version which created ZIP archive self.extract_version = 20 # Version needed to extract archive self.reserved = 0 # Must be zero self.flag_bits = 0 # ZIP flag bits self.volume = 0 # Volume number of file header self.internal_attr = 0 # Internal attributes self.external_attr = 0 # External file attributes # Other attributes are set by class ZipFile: # header_offset Byte offset to the file header # CRC CRC-32 of the uncompressed file # compress_size Size of the compressed file # file_size Size of the uncompressed file def FileHeader(self, zip64=None): """Return the per-file header as a string.""" dt = self.date_time dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2] dostime = dt[3] << 11 | dt[4] << 5 | (dt[5] // 2) if self.flag_bits & 0x08: # Set these to zero because we write them after the file data CRC = compress_size = file_size = 0 else: CRC = self.CRC compress_size = self.compress_size file_size = self.file_size extra = self.extra if zip64 is None: zip64 = file_size > ZIP64_LIMIT or compress_size > ZIP64_LIMIT if zip64: fmt = '<HHQQ' extra = extra + struct.pack(fmt, 1, struct.calcsize(fmt)-4, file_size, compress_size) if file_size > ZIP64_LIMIT or compress_size > ZIP64_LIMIT: if not zip64: raise LargeZipFile("Filesize would require ZIP64 extensions") # File is larger than what fits into a 4 byte integer, # fall back to the ZIP64 extension file_size = 0xffffffff compress_size = 0xffffffff self.extract_version = max(45, self.extract_version) self.create_version = max(45, self.extract_version) filename, flag_bits = self._encodeFilenameFlags() header = struct.pack(structFileHeader, stringFileHeader, self.extract_version, self.reserved, flag_bits, self.compress_type, dostime, dosdate, CRC, compress_size, file_size, len(filename), len(extra)) return header + filename + extra def _encodeFilenameFlags(self): if isinstance(self.filename, unicode): try: return self.filename.encode('ascii'), self.flag_bits except UnicodeEncodeError: return self.filename.encode('utf-8'), self.flag_bits | 0x800 else: return self.filename, self.flag_bits def _decodeFilename(self): if self.flag_bits & 0x800: return self.filename.decode('utf-8') else: return self.filename def _decodeExtra(self): # Try to decode the extra field. extra = self.extra unpack = struct.unpack while len(extra) >= 4: tp, ln = unpack('<HH', extra[:4]) if tp == 1: if ln >= 24: counts = unpack('<QQQ', extra[4:28]) elif ln == 16: counts = unpack('<QQ', extra[4:20]) elif ln == 8: counts = unpack('<Q', extra[4:12]) elif ln == 0: counts = () else: raise RuntimeError, "Corrupt extra field %s"%(ln,) idx = 0 # ZIP64 extension (large files and/or large archives) if self.file_size in (0xffffffffffffffffL, 0xffffffffL): self.file_size = counts[idx] idx += 1 if self.compress_size == 0xFFFFFFFFL: self.compress_size = counts[idx] idx += 1 if self.header_offset == 0xffffffffL: old = self.header_offset self.header_offset = counts[idx] idx+=1 extra = extra[ln+4:] class _ZipDecrypter: """Class to handle decryption of files stored within a ZIP archive. ZIP supports a password-based form of encryption. Even though known plaintext attacks have been found against it, it is still useful to be able to get data out of such a file. Usage: zd = _ZipDecrypter(mypwd) plain_char = zd(cypher_char) plain_text = map(zd, cypher_text) """ def _GenerateCRCTable(): """Generate a CRC-32 table. ZIP encryption uses the CRC32 one-byte primitive for scrambling some internal keys. We noticed that a direct implementation is faster than relying on binascii.crc32(). """ poly = 0xedb88320 table = [0] * 256 for i in range(256): crc = i for j in range(8): if crc & 1: crc = ((crc >> 1) & 0x7FFFFFFF) ^ poly else: crc = ((crc >> 1) & 0x7FFFFFFF) table[i] = crc return table crctable = _GenerateCRCTable() def _crc32(self, ch, crc): """Compute the CRC32 primitive on one byte.""" return ((crc >> 8) & 0xffffff) ^ self.crctable[(crc ^ ord(ch)) & 0xff] def __init__(self, pwd): self.key0 = 305419896 self.key1 = 591751049 self.key2 = 878082192 for p in pwd: self._UpdateKeys(p) def _UpdateKeys(self, c): self.key0 = self._crc32(c, self.key0) self.key1 = (self.key1 + (self.key0 & 255)) & 4294967295 self.key1 = (self.key1 * 134775813 + 1) & 4294967295 self.key2 = self._crc32(chr((self.key1 >> 24) & 255), self.key2) def __call__(self, c): """Decrypt a single character.""" c = ord(c) k = self.key2 | 2 c = c ^ (((k * (k^1)) >> 8) & 255) c = chr(c) self._UpdateKeys(c) return c compressor_names = { 0: 'store', 1: 'shrink', 2: 'reduce', 3: 'reduce', 4: 'reduce', 5: 'reduce', 6: 'implode', 7: 'tokenize', 8: 'deflate', 9: 'deflate64', 10: 'implode', 12: 'bzip2', 14: 'lzma', 18: 'terse', 19: 'lz77', 97: 'wavpack', 98: 'ppmd', } class ZipExtFile(io.BufferedIOBase): """File-like object for reading an archive member. Is returned by ZipFile.open(). """ # Max size supported by decompressor. MAX_N = 1 << 31 - 1 # Read from compressed files in 4k blocks. MIN_READ_SIZE = 4096 # Search for universal newlines or line chunks. PATTERN = re.compile(r'^(?P<chunk>[^\r\n]+)|(?P<newline>\n|\r\n?)') def __init__(self, fileobj, mode, zipinfo, decrypter=None, close_fileobj=False): self._fileobj = fileobj self._decrypter = decrypter self._close_fileobj = close_fileobj self._compress_type = zipinfo.compress_type self._compress_size = zipinfo.compress_size self._compress_left = zipinfo.compress_size if self._compress_type == ZIP_DEFLATED: self._decompressor = zlib.decompressobj(-15) elif self._compress_type != ZIP_STORED: descr = compressor_names.get(self._compress_type) if descr: raise NotImplementedError("compression type %d (%s)" % (self._compress_type, descr)) else: raise NotImplementedError("compression type %d" % (self._compress_type,)) self._unconsumed = '' self._readbuffer = '' self._offset = 0 self._universal = 'U' in mode self.newlines = None # Adjust read size for encrypted files since the first 12 bytes # are for the encryption/password information. if self._decrypter is not None: self._compress_left -= 12 self.mode = mode self.name = zipinfo.filename if hasattr(zipinfo, 'CRC'): self._expected_crc = zipinfo.CRC self._running_crc = crc32(b'') & 0xffffffff else: self._expected_crc = None def readline(self, limit=-1): """Read and return a line from the stream. If limit is specified, at most limit bytes will be read. """ if not self._universal and limit < 0: # Shortcut common case - newline found in buffer. i = self._readbuffer.find('\n', self._offset) + 1 if i > 0: line = self._readbuffer[self._offset: i] self._offset = i return line if not self._universal: return io.BufferedIOBase.readline(self, limit) line = '' while limit < 0 or len(line) < limit: readahead = self.peek(2) if readahead == '': return line # # Search for universal newlines or line chunks. # # The pattern returns either a line chunk or a newline, but not # both. Combined with peek(2), we are assured that the sequence # '\r\n' is always retrieved completely and never split into # separate newlines - '\r', '\n' due to coincidental readaheads. # match = self.PATTERN.search(readahead) newline = match.group('newline') if newline is not None: if self.newlines is None: self.newlines = [] if newline not in self.newlines: self.newlines.append(newline) self._offset += len(newline) return line + '\n' chunk = match.group('chunk') if limit >= 0: chunk = chunk[: limit - len(line)] self._offset += len(chunk) line += chunk return line def peek(self, n=1): """Returns buffered bytes without advancing the position.""" if n > len(self._readbuffer) - self._offset: chunk = self.read(n) if len(chunk) > self._offset: self._readbuffer = chunk + self._readbuffer[self._offset:] self._offset = 0 else: self._offset -= len(chunk) # Return up to 512 bytes to reduce allocation overhead for tight loops. return self._readbuffer[self._offset: self._offset + 512] def readable(self): return True def read(self, n=-1): """Read and return up to n bytes. If the argument is omitted, None, or negative, data is read and returned until EOF is reached.. """ buf = '' if n is None: n = -1 while True: if n < 0: data = self.read1(n) elif n > len(buf): data = self.read1(n - len(buf)) else: return buf if len(data) == 0: return buf buf += data def _update_crc(self, newdata, eof): # Update the CRC using the given data. if self._expected_crc is None: # No need to compute the CRC if we don't have a reference value return self._running_crc = crc32(newdata, self._running_crc) & 0xffffffff # Check the CRC if we're at the end of the file if eof and self._running_crc != self._expected_crc: raise BadZipfile("Bad CRC-32 for file %r" % self.name) def read1(self, n): """Read up to n bytes with at most one read() system call.""" # Simplify algorithm (branching) by transforming negative n to large n. if n < 0 or n is None: n = self.MAX_N # Bytes available in read buffer. len_readbuffer = len(self._readbuffer) - self._offset # Read from file. if self._compress_left > 0 and n > len_readbuffer + len(self._unconsumed): nbytes = n - len_readbuffer - len(self._unconsumed) nbytes = max(nbytes, self.MIN_READ_SIZE) nbytes = min(nbytes, self._compress_left) data = self._fileobj.read(nbytes) self._compress_left -= len(data) if data and self._decrypter is not None: data = ''.join(map(self._decrypter, data)) if self._compress_type == ZIP_STORED: self._update_crc(data, eof=(self._compress_left==0)) self._readbuffer = self._readbuffer[self._offset:] + data self._offset = 0 else: # Prepare deflated bytes for decompression. self._unconsumed += data # Handle unconsumed data. if (len(self._unconsumed) > 0 and n > len_readbuffer and self._compress_type == ZIP_DEFLATED): data = self._decompressor.decompress( self._unconsumed, max(n - len_readbuffer, self.MIN_READ_SIZE) ) self._unconsumed = self._decompressor.unconsumed_tail eof = len(self._unconsumed) == 0 and self._compress_left == 0 if eof: data += self._decompressor.flush() self._update_crc(data, eof=eof) self._readbuffer = self._readbuffer[self._offset:] + data self._offset = 0 # Read from buffer. data = self._readbuffer[self._offset: self._offset + n] self._offset += len(data) return data def close(self): try : if self._close_fileobj: self._fileobj.close() finally: super(ZipExtFile, self).close() class ZipFile(object): """ Class with methods to open, read, write, close, list zip files. z = ZipFile(file, mode="r", compression=ZIP_STORED, allowZip64=False) file: Either the path to the file, or a file-like object. If it is a path, the file will be opened and closed by ZipFile. mode: The mode can be either read "r", write "w" or append "a". compression: ZIP_STORED (no compression) or ZIP_DEFLATED (requires zlib). allowZip64: if True ZipFile will create files with ZIP64 extensions when needed, otherwise it will raise an exception when this would be necessary. """ fp = None # Set here since __del__ checks it def __init__(self, file, mode="r", compression=ZIP_STORED, allowZip64=False): """Open the ZIP file with mode read "r", write "w" or append "a".""" if mode not in ("r", "w", "a"): raise RuntimeError('ZipFile() requires mode "r", "w", or "a"') if compression == ZIP_STORED: pass elif compression == ZIP_DEFLATED: if not zlib: raise RuntimeError,\ "Compression requires the (missing) zlib module" else: raise RuntimeError, "That compression method is not supported" self._allowZip64 = allowZip64 self._didModify = False self.debug = 0 # Level of printing: 0 through 3 self.NameToInfo = {} # Find file info given name self.filelist = [] # List of ZipInfo instances for archive self.compression = compression # Method of compression self.mode = key = mode.replace('b', '')[0] self.pwd = None self._comment = '' # Check if we were passed a file-like object if isinstance(file, basestring): self._filePassed = 0 self.filename = file modeDict = {'r' : 'rb', 'w': 'wb', 'a' : 'r+b'} try: self.fp = open(file, modeDict[mode]) except IOError: if mode == 'a': mode = key = 'w' self.fp = open(file, modeDict[mode]) else: raise else: self._filePassed = 1 self.fp = file self.filename = getattr(file, 'name', None) try: if key == 'r': self._RealGetContents() elif key == 'w': # set the modified flag so central directory gets written # even if no files are added to the archive self._didModify = True elif key == 'a': try: # See if file is a zip file self._RealGetContents() # seek to start of directory and overwrite self.fp.seek(self.start_dir, 0) except BadZipfile: # file is not a zip file, just append self.fp.seek(0, 2) # set the modified flag so central directory gets written # even if no files are added to the archive self._didModify = True else: raise RuntimeError('Mode must be "r", "w" or "a"') except: fp = self.fp self.fp = None if not self._filePassed: fp.close() raise def __enter__(self): return self def __exit__(self, type, value, traceback): self.close() def _RealGetContents(self): """Read in the table of contents for the ZIP file.""" fp = self.fp try: endrec = _EndRecData(fp) except IOError: raise BadZipfile("File is not a zip file") if not endrec: raise BadZipfile, "File is not a zip file" if self.debug > 1: print endrec size_cd = endrec[_ECD_SIZE] # bytes in central directory offset_cd = endrec[_ECD_OFFSET] # offset of central directory self._comment = endrec[_ECD_COMMENT] # archive comment # "concat" is zero, unless zip was concatenated to another file concat = endrec[_ECD_LOCATION] - size_cd - offset_cd if endrec[_ECD_SIGNATURE] == stringEndArchive64: # If Zip64 extension structures are present, account for them concat -= (sizeEndCentDir64 + sizeEndCentDir64Locator) if self.debug > 2: inferred = concat + offset_cd print "given, inferred, offset", offset_cd, inferred, concat # self.start_dir: Position of start of central directory self.start_dir = offset_cd + concat fp.seek(self.start_dir, 0) data = fp.read(size_cd) fp = cStringIO.StringIO(data) total = 0 while total < size_cd: centdir = fp.read(sizeCentralDir) if len(centdir) != sizeCentralDir: raise BadZipfile("Truncated central directory") centdir = struct.unpack(structCentralDir, centdir) if centdir[_CD_SIGNATURE] != stringCentralDir: raise BadZipfile("Bad magic number for central directory") if self.debug > 2: print centdir filename = fp.read(centdir[_CD_FILENAME_LENGTH]) # Create ZipInfo instance to store file information x = ZipInfo(filename) x.extra = fp.read(centdir[_CD_EXTRA_FIELD_LENGTH]) x.comment = fp.read(centdir[_CD_COMMENT_LENGTH]) x.header_offset = centdir[_CD_LOCAL_HEADER_OFFSET] (x.create_version, x.create_system, x.extract_version, x.reserved, x.flag_bits, x.compress_type, t, d, x.CRC, x.compress_size, x.file_size) = centdir[1:12] x.volume, x.internal_attr, x.external_attr = centdir[15:18] # Convert date/time code to (year, month, day, hour, min, sec) x._raw_time = t x.date_time = ( (d>>9)+1980, (d>>5)&0xF, d&0x1F, t>>11, (t>>5)&0x3F, (t&0x1F) * 2 ) x._decodeExtra() x.header_offset = x.header_offset + concat x.filename = x._decodeFilename() self.filelist.append(x) self.NameToInfo[x.filename] = x # update total bytes read from central directory total = (total + sizeCentralDir + centdir[_CD_FILENAME_LENGTH] + centdir[_CD_EXTRA_FIELD_LENGTH] + centdir[_CD_COMMENT_LENGTH]) if self.debug > 2: print "total", total def namelist(self): """Return a list of file names in the archive.""" l = [] for data in self.filelist: l.append(data.filename) return l def infolist(self): """Return a list of class ZipInfo instances for files in the archive.""" return self.filelist def printdir(self): """Print a table of contents for the zip file.""" print "%-46s %19s %12s" % ("File Name", "Modified ", "Size") for zinfo in self.filelist: date = "%d-%02d-%02d %02d:%02d:%02d" % zinfo.date_time[:6] print "%-46s %s %12d" % (zinfo.filename, date, zinfo.file_size) def testzip(self): """Read all the files and check the CRC.""" chunk_size = 2 ** 20 for zinfo in self.filelist: try: # Read by chunks, to avoid an OverflowError or a # MemoryError with very large embedded files. with self.open(zinfo.filename, "r") as f: while f.read(chunk_size): # Check CRC-32 pass except BadZipfile: return zinfo.filename def getinfo(self, name): """Return the instance of ZipInfo given 'name'.""" info = self.NameToInfo.get(name) if info is None: raise KeyError( 'There is no item named %r in the archive' % name) return info def setpassword(self, pwd): """Set default password for encrypted files.""" self.pwd = pwd @property def comment(self): """The comment text associated with the ZIP file.""" return self._comment @comment.setter def comment(self, comment): # check for valid comment length if len(comment) > ZIP_MAX_COMMENT: import warnings warnings.warn('Archive comment is too long; truncating to %d bytes' % ZIP_MAX_COMMENT, stacklevel=2) comment = comment[:ZIP_MAX_COMMENT] self._comment = comment self._didModify = True def read(self, name, pwd=None): """Return file bytes (as a string) for name.""" return self.open(name, "r", pwd).read() def open(self, name, mode="r", pwd=None): """Return file-like object for 'name'.""" if mode not in ("r", "U", "rU"): raise RuntimeError, 'open() requires mode "r", "U", or "rU"' if not self.fp: raise RuntimeError, \ "Attempt to read ZIP archive that was already closed" # Only open a new file for instances where we were not # given a file object in the constructor if self._filePassed: zef_file = self.fp should_close = False else: zef_file = open(self.filename, 'rb') should_close = True try: # Make sure we have an info object if isinstance(name, ZipInfo): # 'name' is already an info object zinfo = name else: # Get info object for name zinfo = self.getinfo(name) zef_file.seek(zinfo.header_offset, 0) # Skip the file header: fheader = zef_file.read(sizeFileHeader) if len(fheader) != sizeFileHeader: raise BadZipfile("Truncated file header") fheader = struct.unpack(structFileHeader, fheader) if fheader[_FH_SIGNATURE] != stringFileHeader: raise BadZipfile("Bad magic number for file header") fname = zef_file.read(fheader[_FH_FILENAME_LENGTH]) if fheader[_FH_EXTRA_FIELD_LENGTH]: zef_file.read(fheader[_FH_EXTRA_FIELD_LENGTH]) if fname != zinfo.orig_filename: raise BadZipfile, \ 'File name in directory "%s" and header "%s" differ.' % ( zinfo.orig_filename, fname) # check for encrypted flag & handle password is_encrypted = zinfo.flag_bits & 0x1 zd = None if is_encrypted: if not pwd: pwd = self.pwd if not pwd: raise RuntimeError, "File %s is encrypted, " \ "password required for extraction" % name zd = _ZipDecrypter(pwd) # The first 12 bytes in the cypher stream is an encryption header # used to strengthen the algorithm. The first 11 bytes are # completely random, while the 12th contains the MSB of the CRC, # or the MSB of the file time depending on the header type # and is used to check the correctness of the password. bytes = zef_file.read(12) h = map(zd, bytes[0:12]) if zinfo.flag_bits & 0x8: # compare against the file type from extended local headers check_byte = (zinfo._raw_time >> 8) & 0xff else: # compare against the CRC otherwise check_byte = (zinfo.CRC >> 24) & 0xff if ord(h[11]) != check_byte: raise RuntimeError("Bad password for file", name) return ZipExtFile(zef_file, mode, zinfo, zd, close_fileobj=should_close) except: if should_close: zef_file.close() raise def extract(self, member, path=None, pwd=None): """Extract a member from the archive to the current working directory, using its full name. Its file information is extracted as accurately as possible. `member' may be a filename or a ZipInfo object. You can specify a different directory using `path'. """ if not isinstance(member, ZipInfo): member = self.getinfo(member) if path is None: path = os.getcwd() return self._extract_member(member, path, pwd) def extractall(self, path=None, members=None, pwd=None): """Extract all members from the archive to the current working directory. `path' specifies a different directory to extract to. `members' is optional and must be a subset of the list returned by namelist(). """ if members is None: members = self.namelist() for zipinfo in members: self.extract(zipinfo, path, pwd) def _extract_member(self, member, targetpath, pwd): """Extract the ZipInfo object 'member' to a physical file on the path targetpath. """ # build the destination pathname, replacing # forward slashes to platform specific separators. arcname = member.filename.replace('/', os.path.sep) if os.path.altsep: arcname = arcname.replace(os.path.altsep, os.path.sep) # interpret absolute pathname as relative, remove drive letter or # UNC path, redundant separators, "." and ".." components. arcname = os.path.splitdrive(arcname)[1] arcname = os.path.sep.join(x for x in arcname.split(os.path.sep) if x not in ('', os.path.curdir, os.path.pardir)) if os.path.sep == '\\': # filter illegal characters on Windows illegal = ':<>|"?*' if isinstance(arcname, unicode): table = {ord(c): ord('_') for c in illegal} else: table = string.maketrans(illegal, '_' * len(illegal)) arcname = arcname.translate(table) # remove trailing dots arcname = (x.rstrip('.') for x in arcname.split(os.path.sep)) arcname = os.path.sep.join(x for x in arcname if x) targetpath = os.path.join(targetpath, arcname) targetpath = os.path.normpath(targetpath) # Create all upper directories if necessary. upperdirs = os.path.dirname(targetpath) if upperdirs and not os.path.exists(upperdirs): os.makedirs(upperdirs) if member.filename[-1] == '/': if not os.path.isdir(targetpath): os.mkdir(targetpath) return targetpath with self.open(member, pwd=pwd) as source, \ file(targetpath, "wb") as target: shutil.copyfileobj(source, target) return targetpath def _writecheck(self, zinfo): """Check for errors before writing a file to the archive.""" if zinfo.filename in self.NameToInfo: import warnings warnings.warn('Duplicate name: %r' % zinfo.filename, stacklevel=3) if self.mode not in ("w", "a"): raise RuntimeError, 'write() requires mode "w" or "a"' if not self.fp: raise RuntimeError, \ "Attempt to write ZIP archive that was already closed" if zinfo.compress_type == ZIP_DEFLATED and not zlib: raise RuntimeError, \ "Compression requires the (missing) zlib module" if zinfo.compress_type not in (ZIP_STORED, ZIP_DEFLATED): raise RuntimeError, \ "That compression method is not supported" if not self._allowZip64: requires_zip64 = None if len(self.filelist) >= ZIP_FILECOUNT_LIMIT: requires_zip64 = "Files count" elif zinfo.file_size > ZIP64_LIMIT: requires_zip64 = "Filesize" elif zinfo.header_offset > ZIP64_LIMIT: requires_zip64 = "Zipfile size" if requires_zip64: raise LargeZipFile(requires_zip64 + " would require ZIP64 extensions") def write(self, filename, arcname=None, compress_type=None): """Put the bytes from filename into the archive under the name arcname.""" if not self.fp: raise RuntimeError( "Attempt to write to ZIP archive that was already closed") st = os.stat(filename) isdir = stat.S_ISDIR(st.st_mode) mtime = time.localtime(st.st_mtime) date_time = mtime[0:6] # Create ZipInfo instance to store file information if arcname is None: arcname = filename arcname = os.path.normpath(os.path.splitdrive(arcname)[1]) while arcname[0] in (os.sep, os.altsep): arcname = arcname[1:] if isdir: arcname += '/' zinfo = ZipInfo(arcname, date_time) zinfo.external_attr = (st[0] & 0xFFFF) << 16L # Unix attributes if isdir: zinfo.compress_type = ZIP_STORED elif compress_type is None: zinfo.compress_type = self.compression else: zinfo.compress_type = compress_type zinfo.file_size = st.st_size zinfo.flag_bits = 0x00 zinfo.header_offset = self.fp.tell() # Start of header bytes self._writecheck(zinfo) self._didModify = True if isdir: zinfo.file_size = 0 zinfo.compress_size = 0 zinfo.CRC = 0 zinfo.external_attr |= 0x10 # MS-DOS directory flag self.filelist.append(zinfo) self.NameToInfo[zinfo.filename] = zinfo self.fp.write(zinfo.FileHeader(False)) return with open(filename, "rb") as fp: # Must overwrite CRC and sizes with correct data later zinfo.CRC = CRC = 0 zinfo.compress_size = compress_size = 0 # Compressed size can be larger than uncompressed size zip64 = self._allowZip64 and \ zinfo.file_size * 1.05 > ZIP64_LIMIT self.fp.write(zinfo.FileHeader(zip64)) if zinfo.compress_type == ZIP_DEFLATED: cmpr = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION, zlib.DEFLATED, -15) else: cmpr = None file_size = 0 while 1: buf = fp.read(1024 * 8) if not buf: break file_size = file_size + len(buf) CRC = crc32(buf, CRC) & 0xffffffff if cmpr: buf = cmpr.compress(buf) compress_size = compress_size + len(buf) self.fp.write(buf) if cmpr: buf = cmpr.flush() compress_size = compress_size + len(buf) self.fp.write(buf) zinfo.compress_size = compress_size else: zinfo.compress_size = file_size zinfo.CRC = CRC zinfo.file_size = file_size if not zip64 and self._allowZip64: if file_size > ZIP64_LIMIT: raise RuntimeError('File size has increased during compressing') if compress_size > ZIP64_LIMIT: raise RuntimeError('Compressed size larger than uncompressed size') # Seek backwards and write file header (which will now include # correct CRC and file sizes) position = self.fp.tell() # Preserve current position in file self.fp.seek(zinfo.header_offset, 0) self.fp.write(zinfo.FileHeader(zip64)) self.fp.seek(position, 0) self.filelist.append(zinfo) self.NameToInfo[zinfo.filename] = zinfo def writestr(self, zinfo_or_arcname, bytes, compress_type=None): """Write a file into the archive. The contents is the string 'bytes'. 'zinfo_or_arcname' is either a ZipInfo instance or the name of the file in the archive.""" if not isinstance(zinfo_or_arcname, ZipInfo): zinfo = ZipInfo(filename=zinfo_or_arcname, date_time=time.localtime(time.time())[:6]) zinfo.compress_type = self.compression if zinfo.filename[-1] == '/': zinfo.external_attr = 0o40775 << 16 # drwxrwxr-x zinfo.external_attr |= 0x10 # MS-DOS directory flag else: zinfo.external_attr = 0o600 << 16 # ?rw------- else: zinfo = zinfo_or_arcname if not self.fp: raise RuntimeError( "Attempt to write to ZIP archive that was already closed") if compress_type is not None: zinfo.compress_type = compress_type zinfo.file_size = len(bytes) # Uncompressed size zinfo.header_offset = self.fp.tell() # Start of header bytes self._writecheck(zinfo) self._didModify = True zinfo.CRC = crc32(bytes) & 0xffffffff # CRC-32 checksum if zinfo.compress_type == ZIP_DEFLATED: co = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION, zlib.DEFLATED, -15) bytes = co.compress(bytes) + co.flush() zinfo.compress_size = len(bytes) # Compressed size else: zinfo.compress_size = zinfo.file_size zip64 = zinfo.file_size > ZIP64_LIMIT or \ zinfo.compress_size > ZIP64_LIMIT if zip64 and not self._allowZip64: raise LargeZipFile("Filesize would require ZIP64 extensions") self.fp.write(zinfo.FileHeader(zip64)) self.fp.write(bytes) if zinfo.flag_bits & 0x08: # Write CRC and file sizes after the file data fmt = '<LLQQ' if zip64 else '<LLLL' self.fp.write(struct.pack(fmt, _DD_SIGNATURE, zinfo.CRC, zinfo.compress_size, zinfo.file_size)) self.fp.flush() self.filelist.append(zinfo) self.NameToInfo[zinfo.filename] = zinfo def __del__(self): """Call the "close()" method in case the user forgot.""" self.close() def close(self): """Close the file, and for mode "w" and "a" write the ending records.""" if self.fp is None: return try: if self.mode in ("w", "a") and self._didModify: # write ending records pos1 = self.fp.tell() for zinfo in self.filelist: # write central directory dt = zinfo.date_time dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2] dostime = dt[3] << 11 | dt[4] << 5 | (dt[5] // 2) extra = [] if zinfo.file_size > ZIP64_LIMIT \ or zinfo.compress_size > ZIP64_LIMIT: extra.append(zinfo.file_size) extra.append(zinfo.compress_size) file_size = 0xffffffff compress_size = 0xffffffff else: file_size = zinfo.file_size compress_size = zinfo.compress_size if zinfo.header_offset > ZIP64_LIMIT: extra.append(zinfo.header_offset) header_offset = 0xffffffffL else: header_offset = zinfo.header_offset extra_data = zinfo.extra if extra: # Append a ZIP64 field to the extra's extra_data = _strip_extra(extra_data, (1,)) extra_data = struct.pack( '<HH' + 'Q'*len(extra), 1, 8*len(extra), *extra) + extra_data extract_version = max(45, zinfo.extract_version) create_version = max(45, zinfo.create_version) else: extract_version = zinfo.extract_version create_version = zinfo.create_version try: filename, flag_bits = zinfo._encodeFilenameFlags() centdir = struct.pack(structCentralDir, stringCentralDir, create_version, zinfo.create_system, extract_version, zinfo.reserved, flag_bits, zinfo.compress_type, dostime, dosdate, zinfo.CRC, compress_size, file_size, len(filename), len(extra_data), len(zinfo.comment), 0, zinfo.internal_attr, zinfo.external_attr, header_offset) except DeprecationWarning: print >>sys.stderr, (structCentralDir, stringCentralDir, create_version, zinfo.create_system, extract_version, zinfo.reserved, zinfo.flag_bits, zinfo.compress_type, dostime, dosdate, zinfo.CRC, compress_size, file_size, len(zinfo.filename), len(extra_data), len(zinfo.comment), 0, zinfo.internal_attr, zinfo.external_attr, header_offset) raise self.fp.write(centdir) self.fp.write(filename) self.fp.write(extra_data) self.fp.write(zinfo.comment) pos2 = self.fp.tell() # Write end-of-zip-archive record centDirCount = len(self.filelist) centDirSize = pos2 - pos1 centDirOffset = pos1 requires_zip64 = None if centDirCount > ZIP_FILECOUNT_LIMIT: requires_zip64 = "Files count" elif centDirOffset > ZIP64_LIMIT: requires_zip64 = "Central directory offset" elif centDirSize > ZIP64_LIMIT: requires_zip64 = "Central directory size" if requires_zip64: # Need to write the ZIP64 end-of-archive records if not self._allowZip64: raise LargeZipFile(requires_zip64 + " would require ZIP64 extensions") zip64endrec = struct.pack( structEndArchive64, stringEndArchive64, 44, 45, 45, 0, 0, centDirCount, centDirCount, centDirSize, centDirOffset) self.fp.write(zip64endrec) zip64locrec = struct.pack( structEndArchive64Locator, stringEndArchive64Locator, 0, pos2, 1) self.fp.write(zip64locrec) centDirCount = min(centDirCount, 0xFFFF) centDirSize = min(centDirSize, 0xFFFFFFFF) centDirOffset = min(centDirOffset, 0xFFFFFFFF) endrec = struct.pack(structEndArchive, stringEndArchive, 0, 0, centDirCount, centDirCount, centDirSize, centDirOffset, len(self._comment)) self.fp.write(endrec) self.fp.write(self._comment) self.fp.flush() finally: fp = self.fp self.fp = None if not self._filePassed: fp.close() class PyZipFile(ZipFile): """Class to create ZIP archives with Python library files and packages.""" def writepy(self, pathname, basename = ""): """Add all files from "pathname" to the ZIP archive. If pathname is a package directory, search the directory and all package subdirectories recursively for all *.py and enter the modules into the archive. If pathname is a plain directory, listdir *.py and enter all modules. Else, pathname must be a Python *.py file and the module will be put into the archive. Added modules are always module.pyo or module.pyc. This method will compile the module.py into module.pyc if necessary. """ dir, name = os.path.split(pathname) if os.path.isdir(pathname): initname = os.path.join(pathname, "__init__.py") if os.path.isfile(initname): # This is a package directory, add it if basename: basename = "%s/%s" % (basename, name) else: basename = name if self.debug: print "Adding package in", pathname, "as", basename fname, arcname = self._get_codename(initname[0:-3], basename) if self.debug: print "Adding", arcname self.write(fname, arcname) dirlist = os.listdir(pathname) dirlist.remove("__init__.py") # Add all *.py files and package subdirectories for filename in dirlist: path = os.path.join(pathname, filename) root, ext = os.path.splitext(filename) if os.path.isdir(path): if os.path.isfile(os.path.join(path, "__init__.py")): # This is a package directory, add it self.writepy(path, basename) # Recursive call elif ext == ".py": fname, arcname = self._get_codename(path[0:-3], basename) if self.debug: print "Adding", arcname self.write(fname, arcname) else: # This is NOT a package directory, add its files at top level if self.debug: print "Adding files from directory", pathname for filename in os.listdir(pathname): path = os.path.join(pathname, filename) root, ext = os.path.splitext(filename) if ext == ".py": fname, arcname = self._get_codename(path[0:-3], basename) if self.debug: print "Adding", arcname self.write(fname, arcname) else: if pathname[-3:] != ".py": raise RuntimeError, \ 'Files added with writepy() must end with ".py"' fname, arcname = self._get_codename(pathname[0:-3], basename) if self.debug: print "Adding file", arcname self.write(fname, arcname) def _get_codename(self, pathname, basename): """Return (filename, archivename) for the path. Given a module name path, return the correct file path and archive name, compiling if necessary. For example, given /python/lib/string, return (/python/lib/string.pyc, string). """ file_py = pathname + ".py" file_pyc = pathname + ".pyc" file_pyo = pathname + ".pyo" if os.path.isfile(file_pyo) and \ os.stat(file_pyo).st_mtime >= os.stat(file_py).st_mtime: fname = file_pyo # Use .pyo file elif not os.path.isfile(file_pyc) or \ os.stat(file_pyc).st_mtime < os.stat(file_py).st_mtime: import py_compile if self.debug: print "Compiling", file_py try: py_compile.compile(file_py, file_pyc, None, True) except py_compile.PyCompileError,err: print err.msg fname = file_pyc else: fname = file_pyc archivename = os.path.split(fname)[1] if basename: archivename = "%s/%s" % (basename, archivename) return (fname, archivename) def main(args = None): import textwrap USAGE=textwrap.dedent("""\ Usage: zipfile.py -l zipfile.zip # Show listing of a zipfile zipfile.py -t zipfile.zip # Test if a zipfile is valid zipfile.py -e zipfile.zip target # Extract zipfile into target dir zipfile.py -c zipfile.zip src ... # Create zipfile from sources """) if args is None: args = sys.argv[1:] if not args or args[0] not in ('-l', '-c', '-e', '-t'): print USAGE sys.exit(1) if args[0] == '-l': if len(args) != 2: print USAGE sys.exit(1) with ZipFile(args[1], 'r') as zf: zf.printdir() elif args[0] == '-t': if len(args) != 2: print USAGE sys.exit(1) with ZipFile(args[1], 'r') as zf: badfile = zf.testzip() if badfile: print("The following enclosed file is corrupted: {!r}".format(badfile)) print "Done testing" elif args[0] == '-e': if len(args) != 3: print USAGE sys.exit(1) with ZipFile(args[1], 'r') as zf: zf.extractall(args[2]) elif args[0] == '-c': if len(args) < 3: print USAGE sys.exit(1) def addToZip(zf, path, zippath): if os.path.isfile(path): zf.write(path, zippath, ZIP_DEFLATED) elif os.path.isdir(path): if zippath: zf.write(path, zippath) for nm in os.listdir(path): addToZip(zf, os.path.join(path, nm), os.path.join(zippath, nm)) # else: ignore with ZipFile(args[1], 'w', allowZip64=True) as zf: for path in args[2:]: zippath = os.path.basename(path) if not zippath: zippath = os.path.basename(os.path.dirname(path)) if zippath in ('', os.curdir, os.pardir): zippath = '' addToZip(zf, path, zippath) if __name__ == "__main__": main()
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