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1443 lines (1250 loc) · 53.4 KB
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"""
A fork of the Zipfile module to read and write ZIP files from Python 2.6.
This module aims to create deterministic, byte-for-byte identical zip files.
Author: Yan Zhu, yan@mit.edu
Derived from Python 2.6, Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006
Python Software Foundation; All Rights Reserved, License at
http://www.python.org/download/releases/2.6/license/
"""
import struct, os, time, sys, shutil
import binascii, cStringIO, stat
import unicodedata
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
ZIP_MAX_COMMENT = (1 << 16) - 1
# constants for Zip file compression methods
ZIP_STORED = 0
ZIP_DEFLATED = 8
# Other ZIP compression methods not supported
DEFAULT_DATE = (1980,1,1,0,0,0) # hard-coded timestamp
# 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
def normalize_unicode(filename):
"""For dealing with different unicode normalizations in filenames."""
return unicodedata.normalize('NFC', unicode(filename, 'utf-8')).encode('utf-8')
def standardize_filename(filename):
"""Get OS-independent form of filename"""
# 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, "/")
return normalize_unicode(filename)
def is_zipfile(filename):
"""Quickly see if file is a ZIP file by checking the magic number."""
try:
fpin = open(filename, "rb")
endrec = _EndRecData(fpin)
fpin.close()
if endrec:
return True # file has correct magic number
except IOError:
pass
return False
def _EndRecData64(fpin, offset, endrec):
"""
Read the ZIP64 end-of-archive records and use that to update endrec
"""
fpin.seek(offset - sizeEndCentDir64Locator, 2)
data = fpin.read(sizeEndCentDir64Locator)
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)
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 data[0:4] == stringEndArchive and data[-2:] == "\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]
endrec = list(struct.unpack(structEndArchive, recData))
comment = data[start+sizeEndCentDir:]
# check that comment length is correct
if endrec[_ECD_COMMENT_SIZE] == len(comment):
# Append the archive comment and start offset
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
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=DEFAULT_DATE):
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.
self.filename = standardize_filename(filename) # Normalized file name
self.date_time = date_time # year, month, day, hour, min, sec
# 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):
"""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 file_size > ZIP64_LIMIT or compress_size > ZIP64_LIMIT:
# File is larger than what fits into a 4 byte integer,
# fall back to the ZIP64 extension
fmt = '<HHQQ'
extra = extra + struct.pack(fmt,
1, struct.calcsize(fmt)-4, file_size, compress_size)
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 extra:
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
class ZipExtFile:
"""File-like object for reading an archive member.
Is returned by ZipFile.open().
"""
def __init__(self, fileobj, zipinfo, decrypt=None):
self.fileobj = fileobj
self.decrypter = decrypt
self.bytes_read = 0L
self.rawbuffer = ''
self.readbuffer = ''
self.linebuffer = ''
self.eof = False
self.univ_newlines = False
self.nlSeps = ("\n", )
self.lastdiscard = ''
self.compress_type = zipinfo.compress_type
self.compress_size = zipinfo.compress_size
self.closed = False
self.mode = "r"
self.name = zipinfo.filename
# read from compressed files in 64k blocks
self.compreadsize = 64*1024
if self.compress_type == ZIP_DEFLATED:
self.dc = zlib.decompressobj(-15)
def set_univ_newlines(self, univ_newlines):
self.univ_newlines = univ_newlines
# pick line separator char(s) based on universal newlines flag
self.nlSeps = ("\n", )
if self.univ_newlines:
self.nlSeps = ("\r\n", "\r", "\n")
def __iter__(self):
return self
def next(self):
nextline = self.readline()
if not nextline:
raise StopIteration()
return nextline
def close(self):
self.closed = True
def _checkfornewline(self):
nl, nllen = -1, -1
if self.linebuffer:
# ugly check for cases where half of an \r\n pair was
# read on the last pass, and the \r was discarded. In this
# case we just throw away the \n at the start of the buffer.
if (self.lastdiscard, self.linebuffer[0]) == ('\r','\n'):
self.linebuffer = self.linebuffer[1:]
for sep in self.nlSeps:
nl = self.linebuffer.find(sep)
if nl >= 0:
nllen = len(sep)
return nl, nllen
return nl, nllen
def readline(self, size = -1):
"""Read a line with approx. size. If size is negative,
read a whole line.
"""
if size < 0:
size = 2147483647
elif size == 0:
return ''
# check for a newline already in buffer
nl, nllen = self._checkfornewline()
if nl >= 0:
# the next line was already in the buffer
nl = min(nl, size)
else:
# no line break in buffer - try to read more
size -= len(self.linebuffer)
while nl < 0 and size > 0:
buf = self.read(min(size, 100))
if not buf:
break
self.linebuffer += buf
size -= len(buf)
# check for a newline in buffer
nl, nllen = self._checkfornewline()
# we either ran out of bytes in the file, or
# met the specified size limit without finding a newline,
# so return current buffer
if nl < 0:
s = self.linebuffer
self.linebuffer = ''
return s
buf = self.linebuffer[:nl]
self.lastdiscard = self.linebuffer[nl:nl + nllen]
self.linebuffer = self.linebuffer[nl + nllen:]
# line is always returned with \n as newline char (except possibly
# for a final incomplete line in the file, which is handled above).
return buf + "\n"
def readlines(self, sizehint = -1):
"""Return a list with all (following) lines. The sizehint parameter
is ignored in this implementation.
"""
result = []
while True:
line = self.readline()
if not line: break
result.append(line)
return result
def read(self, size = None):
# act like file() obj and return empty string if size is 0
if size == 0:
return ''
# determine read size
bytesToRead = self.compress_size - self.bytes_read
# adjust read size for encrypted files since the first 12 bytes
# are for the encryption/password information
if self.decrypter is not None:
bytesToRead -= 12
if size is not None and size >= 0:
if self.compress_type == ZIP_STORED:
lr = len(self.readbuffer)
bytesToRead = min(bytesToRead, size - lr)
elif self.compress_type == ZIP_DEFLATED:
if len(self.readbuffer) > size:
# the user has requested fewer bytes than we've already
# pulled through the decompressor; don't read any more
bytesToRead = 0
else:
# user will use up the buffer, so read some more
lr = len(self.rawbuffer)
bytesToRead = min(bytesToRead, self.compreadsize - lr)
# avoid reading past end of file contents
if bytesToRead + self.bytes_read > self.compress_size:
bytesToRead = self.compress_size - self.bytes_read
# try to read from file (if necessary)
if bytesToRead > 0:
bytes = self.fileobj.read(bytesToRead)
self.bytes_read += len(bytes)
self.rawbuffer += bytes
# handle contents of raw buffer
if self.rawbuffer:
newdata = self.rawbuffer
self.rawbuffer = ''
# decrypt new data if we were given an object to handle that
if newdata and self.decrypter is not None:
newdata = ''.join(map(self.decrypter, newdata))
# decompress newly read data if necessary
if newdata and self.compress_type == ZIP_DEFLATED:
newdata = self.dc.decompress(newdata)
self.rawbuffer = self.dc.unconsumed_tail
if self.eof and len(self.rawbuffer) == 0:
# we're out of raw bytes (both from the file and
# the local buffer); flush just to make sure the
# decompressor is done
newdata += self.dc.flush()
# prevent decompressor from being used again
self.dc = None
self.readbuffer += newdata
# return what the user asked for
if size is None or len(self.readbuffer) <= size:
bytes = self.readbuffer
self.readbuffer = ''
else:
bytes = self.readbuffer[:size]
self.readbuffer = self.readbuffer[size:]
return bytes
class ZipFile:
""" 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)
if key == 'r':
self._GetContents()
elif key == 'w':
pass
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)
else:
if not self._filePassed:
self.fp.close()
self.fp = None
raise RuntimeError, 'Mode must be "r", "w" or "a"'
def _GetContents(self):
"""Read the directory, making sure we close the file if the format
is bad."""
try:
self._RealGetContents()
except BadZipfile:
if not self._filePassed:
self.fp.close()
self.fp = None
raise
def _RealGetContents(self):
"""Read in the table of contents for the ZIP file."""
fp = self.fp
endrec = _EndRecData(fp)
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 centdir[0:4] != stringCentralDir:
raise BadZipfile, "Bad magic number for central directory"
centdir = struct.unpack(structCentralDir, centdir)
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.
f = self.open(zinfo.filename, "r")
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
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
else:
zef_file = open(self.filename, 'rb')
# 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 fheader[0:4] != stringFileHeader:
raise BadZipfile, "Bad magic number for file header"
fheader = struct.unpack(structFileHeader, fheader)
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)
# build and return a ZipExtFile
if zd is None:
zef = ZipExtFile(zef_file, zinfo)
else:
zef = ZipExtFile(zef_file, zinfo, zd)
# set universal newlines on ZipExtFile if necessary
if "U" in mode:
zef.set_univ_newlines(True)
return zef
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.
# Strip trailing path separator, unless it represents the root.
if (targetpath[-1:] in (os.path.sep, os.path.altsep)
and len(os.path.splitdrive(targetpath)[1]) > 1):
targetpath = targetpath[:-1]
# don't include leading "/" from file name if present
if member.filename[0] == '/':
targetpath = os.path.join(targetpath, member.filename[1:])
else:
targetpath = os.path.join(targetpath, member.filename)
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
source = self.open(member, pwd=pwd)
target = file(targetpath, "wb")
shutil.copyfileobj(source, target)
source.close()
target.close()
return targetpath
def _writecheck(self, zinfo):
"""Check for errors before writing a file to the archive."""
if zinfo.filename in self.NameToInfo:
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