BufDebug.py

from hashlib import md5
from optparse import OptionParser # argparse sucks
import struct
import sys

parser = OptionParser()
parser.add_option("-s", "--source", dest="source",
                  help="SOURCE file containing known good data", metavar="SOURCE",
                  default="read.dat")
parser.add_option("-o", "--output", dest="output",
                  help="OUTPUT file containing questionable data", metavar="OUTPUT",
                  default="write.dat")

def read(source, output, byteCount, le):
    hack = {
        'Source: ': source.read(byteCount),
        'Output: ': output.read(byteCount),
    }
    
    for key in hack:
        # Helpful with eap's net data
        if le:
            bo = "<"
        else:
            bo = ">"
        
        if byteCount == 1:
            type = "B"
        elif byteCount == 2:
            type = "H"
        elif byteCount == 4:
            type = "I"
        elif byteCount == 8:
            type = "Q"
        
        data, = struct.unpack(bo + type, hack[key])
        print("\t%s %s" % (key, hex(data)))
    return True

def _read_safe_string(stream):
    info, = struct.unpack("<H", stream.read(2))
    info &= ~0xf000
    if info == 0:
        return ""
    
    buf = stream.read(info)
    if (buf[0] & 0x80):
        string = ""
        for i in range(len(buf)):
            string += chr(struct.pack("B", (~buf[i] & 0xFF))[0])
    else:
        string = str(buf)
    return string

def read_safe_string(source, output):
    hack = {
        'Source: ': source,
        'Output: ': output,
    }
    
    for key in hack:
        string = _read_safe_string(hack[key])
        print("\t%s '%s'" % (key, string))
    return True

def read_uoid(source, output):
    hack = {
        'Source: ': source,
        'Output: ': output,
    }
    
    for key in hack:
        stream = hack[key]
        cf, = struct.unpack("B", stream.read(1))
        # Begin plLocation
        pageID, = struct.unpack("<I", stream.read(4))
        stream.read(2) # Flags
        # End plLocation
        # Begin LoadMask
        if cf & 0x02:
            stream.read(1)
        # End LoadMask
        pCreId, = struct.unpack("<H", stream.read(2))
        objId,  = struct.unpack("<I", stream.read(4))
        name = _read_safe_string(stream)
        if cf & 0x01:
            cloneId = struct.unpack("<I", stream.read(4))
            clonePlayerId = struct.unpack("<I", stream.read(4))
        else:
            cloneId = 0
            clonePlayerId = 0
        
        if cloneId or clonePlayerId:
            print("\t%s [Page:%08X] [pCreId:%04X] [Obj:%s] [CloneId:%i] [ClonePlayer:%i]" % (key, pageID, pCreId, name, cloneId, clonePlayerId))
        else:
            print("\t%s [Page:%08X] [pCreId:%04X] [Obj:%s]" % (key, pageID, pCreId, name))
    return True

def run_cmd(source, output, cmd):
    if cmd == "read8()":
        # Who cares about BO here?
        return read(source, output, 1, True)
    elif cmd == "readle16()":
        return read(source, output, 2, True)
    elif cmd == "readle32()":
        return read(source, output, 4, True)
    elif cmd == "readle64()":
        return read(source, output, 8, True)
    elif cmd == "readbe16()":
        return read(source, output, 2, False)
    elif cmd == "readbe32()":
        return read(source, output, 4, False)
    elif cmd == "readbe64()":
        return read(source, output, 8, False)
    elif cmd == "readsafestring()":
        return read_safe_string(source, output)
    elif cmd == "readuoid()":
        return read_uoid(source, output)
    else:
        print("\tWARNING: I don't know that command!")
        return True

if __name__ == "__main__":
    (options, args) = parser.parse_args()
    try:
        source = open(options.source, "rb")
        output = open(options.output, "rb")
    except:
        print("ERROR: Invalid file specified")
        sys.exit()
    
    # Quick compare the files
    sBuf = source.read()
    oBuf = output.read()
    if md5(sBuf) == md5(oBuf):
        print("Files have equivalent hashes, so they're probably the same...")
        sys.exit()
    source.seek(0)
    output.seek(0)
    
    running = True
    while (running):
        cmd = input("PyBufDebug> ")
        running = run_cmd(source, output, cmd.lower())
    source.close()
    output.close()