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unpacknpk.py
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#!/usr/bin/env python
# npk format
# ---
# 0-4 : '\x1e\xf1\xd0\xba'
# 4-8 : len(data - 8) ===> The size of the package
# 8-14 : '\x01\x00 \x00\x00\x00'
# 14-30: description ===> 16 chars to put a short name
# 30-34: ?? | ==> version #1 - used in this header again (revision, 'f' (102), minor, major)
# 34-38: ?? | ==> version #2 - used in the data part (epoch time of package build)
# | Actualy seems like header[30:42] == each_data_header[12:24]...
# | Both appear as integers in /var/pdb/.../version
# 38-42: 0
# 42-46: 0
# 46-48: 16
# 48-50: 4 |
# 50-52: 0 | ==> Maybe int size of the architecture identifier that follows
# 52-56: "i386"
# 56-58: 2
# 58-62: long description size ===> how many chars follow
# 62-x : long description text
# +24: '\x03\x00"\x00\x00\x00\x01\x00system\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
# +8 : '2f\t\x02\x00\x00\x00\x00' |
# +8 : '2f\t\x02\x00\x00\x00\x00' | ==> two same headers (separators?)
# first 4 like header[30:34]
# last 4 always 0
#
# what follows are headers of 1 short (type) and 1 int (size):
# type 7, 8: some kind of script
# type 4: data
#
# the content is directly after the header
#
# in case of data it is commpressed with zlib
#
# uncompressed data has 30 byte headers:
#
# 0-1 : permissions: 237 is executable (755), 164 is non executable (644) |
# 1-2 : file type: 65 dir, 129 file | ==> ST_MODE from stat()
# 2-4 : 0 - could be user/group
# 4-8 : 0 - could be user/group
# 8-12 : last modification time (ST_MTIME) as reported by stat()
# 12-24: version stuff and a 0 (see above...)
# 24-28: data size
# 28-30: file name size
#
# then comes the file name and after that the data
import sys
import zlib
import os
from struct import pack, unpack
from time import ctime
def parse_npk(filename):
f = open(filename, "r")
data = f.read()
f.close()
if data[10] == "$":
# Switch to newer npk format
print "Version 6 npk reader"
header = data[:66]
dsize = unpack("I", header[62:66])[0] # Description size
header += data[66:66+dsize+40]
print repr(header[38:58])
print "Magic:", repr(header[0:4]), "should be:", repr('\x1e\xf1\xd0\xba')
print "Size after this:", unpack("I", header[4:8])[0], "Header size:", len(header), "Data size:", len(data)
print "Unknown stuff:", repr(header[8:14]), "should be:", repr('\x01\x00 \x00\x00\x00')
print "Short description:", header[14:30]
print "Revision, unknown, Minor, Major:", repr(header[30:34]), unpack("BBBB", header[30:34])
print "Build time:", repr(header[34:38]), ctime(unpack("I", header[34:38])[0])
print "Another number:", repr(header[38:42])
print "Some other numbers:", unpack("IIHHH", header[42:56]), "should be: (0, 2, 16, 4, 0)"
print "Architecture:", header[56:60]
print "Another number:", unpack("H", header[60:62]), "should be: (2,)"
print "Long description:", repr(header[66:66+dsize])
# print "Next 24 chars:", repr(header[62+dsize:62+dsize+24])
# print " should be:", repr('\x03\x00"\x00\x00\x00\x01\x00system\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
# print "Separators:", repr(header[62+dsize+24:62+dsize+32]), repr(header[62+dsize+32:62+dsize+40])
# print " first 4:", unpack("BBBB",header[62+dsize+24:62+dsize+28]), unpack("BBBB",header[62+dsize+32:62+dsize+36])
# print ""
data = data[66+dsize:]
else:
# Older npk format
print "Version 5 npk reader"
header = data[:62]
dsize = unpack("I", header[58:62])[0] # Description size
header += data[62:62+dsize+40]
print repr(header[38:58])
print "Magic:", repr(header[0:4]), "should be:", repr('\x1e\xf1\xd0\xba')
print "Size after this:", unpack("I", header[4:8])[0], "Header size:", len(header), "Data size:", len(data)
print "Unknown stuff:", repr(header[8:14]), "should be:", repr('\x01\x00 \x00\x00\x00')
print "Short description:", header[14:30]
print "Revision, unknown, Minor, Major:", repr(header[30:34]), unpack("BBBB", header[30:34])
print "Build time:", repr(header[34:38]), ctime(unpack("I", header[34:38])[0])
print "Some other numbers:", unpack("IIHHH", header[38:52]), "should be: (0, 0, 16, 4, 0)"
print "Architecture:", header[52:56]
print "Another number:", unpack("H", header[56:58]), "should be: (2,)"
print "Long description:", repr(header[62:62+dsize])
# print "Next 24 chars:", repr(header[62+dsize:62+dsize+24])
# print " should be:", repr('\x03\x00"\x00\x00\x00\x01\x00system\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
# print "Separators:", repr(header[62+dsize+24:62+dsize+32]), repr(header[62+dsize+32:62+dsize+40])
# print " first 4:", unpack("BBBB",header[62+dsize+24:62+dsize+28]), unpack("BBBB",header[62+dsize+32:62+dsize+36])
# print ""
res=[]
while len(data)>6:
type = unpack("H", data[:2])[0]
size = unpack("I", data[2:6])[0]
print "Found data of type:", type, "size:", size
contents = data[6:6+size]
#print contents
if type == 3:
print " Contents (system):", repr(contents)
if type == 4:
contents = zlib.decompress(contents)
print " Uncompressing data..."
if type == 7:
print " Contents (oninstall):", repr(contents)
if type == 8:
print " Contents (onuninstall):", repr(contents)
if type == 21:
print " Squash File System"
res.append({"type": type, "size": size, "contents": contents})
data = data[6+size:]
print ""
print "Returning the raw header and the rest of the file (each part in a list)"
print ""
return header, res
def parse_data(data):
res = []
while len(data)>30:
header = data[:30]
dsize = unpack("I", header[24:28])[0]
fsize = unpack("H", header[28:30])[0]
if len(data) - 30 - fsize - dsize < 0:
dsize = len(data) - 30 - fsize
fstuff = data[30:30+fsize]
dstuff = data[30+fsize:30+fsize+dsize]
res.append({"header": header, "file": fstuff, "data": dstuff})
data = data[30+fsize+dsize:]
return res
if __name__ == "__main__":
if len(sys.argv) > 1:
for i in sys.argv[1:]:
header, res = parse_npk(i)
for j in res:
if j["type"] == 21:
print "SquashFS found in package, extract 'squashfs' by using unsquashfs."
f = open("squashfs", "w")
f.write(j["contents"])
f.close()
if j["type"] == 4:
print "Files in package:"
data = parse_data(j["contents"])
for k in data:
perm, type, z1, z2, tim = unpack("BBHII", k["header"][:12])
if type == 65:
type = "dir"
if not os.access(k["file"], os.F_OK):
os.makedirs(k["file"])
if type == 129:
type = "fil"
f = open(k["file"], "w")
f.write(k["data"])
f.close()
os.chmod(k["file"], int(perm))
if type == 161:
type = "sym"
os.symlink(k["data"],k["file"])
# os.chmod(k["file"], int(perm))
if perm == 164:
perm = "nx"
if perm == 237:
perm = "ex"
print type, perm, k["file"], tim