undexopt

#!/usr/bin/env python
# undexopt.py

import sys, os
import struct
import zipfile

OPT_MAGIC = 'dey\n'
OPT_VER   = '036\0'

optheader = '8s8i'
header_size = struct.calcsize(optheader)

def extractDex(odexfile):
    f = open(odexfile)
    header = struct.unpack(optheader, f.read(header_size))
    magic, offset, length, depsoffset, depslength, optoffset, optlength, flag, checksum = header
    f.seek(offset, os.SEEK_SET)
    return f.read(length)

def addJar(jarfile, dexbuf):
    out = zipfile.ZipFile(jarfile, 'a')
    out.writestr('classes.dex', dexbuf)

if __name__ == '__main__':
    if len(sys.argv) == 3:
        infile, outfile = sys.argv[1:3]
    elif len(sys.argv) == 4:
        infile, apk, outfile = sys.argv[1:4]
        import shutil
        shutil.copy(apk, outfile)
    else:
        print 'usage: %s odexfile apkfile [outfile]'%sys.argv[0]
        sys.exit(-1)

    dex = extractDex(infile)
    addJar(outfile, dex)