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-rw-r--r--scripts/external_libs/dpkt-1.8.6.2/dpkt/gzip.py123
1 files changed, 123 insertions, 0 deletions
diff --git a/scripts/external_libs/dpkt-1.8.6.2/dpkt/gzip.py b/scripts/external_libs/dpkt-1.8.6.2/dpkt/gzip.py
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+++ b/scripts/external_libs/dpkt-1.8.6.2/dpkt/gzip.py
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+# $Id: gzip.py 23 2006-11-08 15:45:33Z dugsong $
+# -*- coding: utf-8 -*-
+"""GNU zip."""
+
+import struct
+import zlib
+import dpkt
+
+
+# RFC 1952
+GZIP_MAGIC = '\x1f\x8b'
+
+# Compression methods
+GZIP_MSTORED = 0
+GZIP_MCOMPRESS = 1
+GZIP_MPACKED = 2
+GZIP_MLZHED = 3
+GZIP_MDEFLATE = 8
+
+# Flags
+GZIP_FTEXT = 0x01
+GZIP_FHCRC = 0x02
+GZIP_FEXTRA = 0x04
+GZIP_FNAME = 0x08
+GZIP_FCOMMENT = 0x10
+GZIP_FENCRYPT = 0x20
+GZIP_FRESERVED = 0xC0
+
+# OS
+GZIP_OS_MSDOS = 0
+GZIP_OS_AMIGA = 1
+GZIP_OS_VMS = 2
+GZIP_OS_UNIX = 3
+GZIP_OS_VMCMS = 4
+GZIP_OS_ATARI = 5
+GZIP_OS_OS2 = 6
+GZIP_OS_MACOS = 7
+GZIP_OS_ZSYSTEM = 8
+GZIP_OS_CPM = 9
+GZIP_OS_TOPS20 = 10
+GZIP_OS_WIN32 = 11
+GZIP_OS_QDOS = 12
+GZIP_OS_RISCOS = 13
+GZIP_OS_UNKNOWN = 255
+
+GZIP_FENCRYPT_LEN = 12
+
+
+class GzipExtra(dpkt.Packet):
+ __hdr__ = (
+ ('id', '2s', ''),
+ ('len', 'H', 0)
+ )
+
+
+class Gzip(dpkt.Packet):
+ __hdr__ = (
+ ('magic', '2s', GZIP_MAGIC),
+ ('method', 'B', GZIP_MDEFLATE),
+ ('flags', 'B', 0),
+ ('mtime', 'I', 0),
+ ('xflags', 'B', 0),
+ ('os', 'B', GZIP_OS_UNIX),
+
+ ('extra', '0s', ''), # XXX - GZIP_FEXTRA
+ ('filename', '0s', ''), # XXX - GZIP_FNAME
+ ('comment', '0s', '') # XXX - GZIP_FCOMMENT
+ )
+
+ def unpack(self, buf):
+ super(Gzip, self).unpack(buf)
+ if self.flags & GZIP_FEXTRA:
+ n = struct.unpack(self.data[:2], '>H')[0]
+ self.extra = GzipExtra(self.data[2:2 + n])
+ self.data = self.data[2 + n:]
+ if self.flags & GZIP_FNAME:
+ n = self.data.find('\x00')
+ self.filename = self.data[:n]
+ self.data = self.data[n + 1:]
+ if self.flags & GZIP_FCOMMENT:
+ n = self.data.find('\x00')
+ self.comment = self.data[:n]
+ self.data = self.data[n + 1:]
+ if self.flags & GZIP_FENCRYPT:
+ self.data = self.data[GZIP_FENCRYPT_LEN:] # XXX - skip
+ if self.flags & GZIP_FHCRC:
+ self.data = self.data[2:] # XXX - skip
+
+ def pack_hdr(self):
+ l = []
+ if self.extra:
+ self.flags |= GZIP_FEXTRA
+ s = str(self.extra)
+ l.append(struct.pack('>H', len(s)))
+ l.append(s)
+ if self.filename:
+ self.flags |= GZIP_FNAME
+ l.append(self.filename)
+ l.append('\x00')
+ if self.comment:
+ self.flags |= GZIP_FCOMMENT
+ l.append(self.comment)
+ l.append('\x00')
+ l.insert(0, super(Gzip, self).pack_hdr())
+ return ''.join(l)
+
+ def compress(self):
+ """Compress self.data."""
+ c = zlib.compressobj(9, zlib.DEFLATED, -zlib.MAX_WBITS,
+ zlib.DEF_MEM_LEVEL, 0)
+ self.data = c.compress(self.data)
+
+ def decompress(self):
+ """Return decompressed payload."""
+ d = zlib.decompressobj(-zlib.MAX_WBITS)
+ return d.decompress(self.data)
+
+
+if __name__ == '__main__':
+ import sys
+
+ gz = Gzip(open(sys.argv[1]).read())
+ print `gz`, `gz.decompress()`