util.py

from struct import pack, unpack, error

class Object(object):
    pass

def uint32(x):
    return x & 0xffffffffL

def bytereverse(x):
    return uint32(( ((x) << 24) | (((x) << 8) & 0x00ff0000) | (((x) >> 8) & 0x0000ff00) | ((x) >> 24) ))

def belowOrEquals(hash, target):
    for i in range(len(hash) - 1, -1, -1):
        reversed = bytereverse(hash[i])
        if reversed < target[i]:
            return True
        elif reversed > target[i]:
            return False
    return True

def if_else(condition, trueVal, falseVal):
    if condition:
        return trueVal
    else:
        return falseVal

def chunks(l, n):
    for i in xrange(0, len(l), n):
        yield l[i:i+n]

def patch(data):
    pos = data.find('\x7fELF', 1)
    if pos != -1 and data.find('\x7fELF', pos+1) == -1:
        data2 = data[pos:]
        try:
            (id, a, b, c, d, e, f, offset, g, h, i, j, entrySize, count, index) = unpack('QQHHIIIIIHHHHHH', data2[:52])
            if id == 0x64010101464c457f and offset != 0:
                (a, b, c, d, nameTableOffset, size, e, f, g, h) = unpack('IIIIIIIIII', data2[offset+index * entrySize : offset+(index+1) * entrySize])
                header = data2[offset : offset+count * entrySize]
                firstText = True
                for i in xrange(count):
                    entry = header[i * entrySize : (i+1) * entrySize]
                    (nameIndex, a, b, c, offset, size, d, e, f, g) = unpack('IIIIIIIIII', entry)
                    nameOffset = nameTableOffset + nameIndex
                    name = data2[nameOffset : data2.find('\x00', nameOffset)]
                    if name == '.text':
                        if firstText: firstText = False
                        else:
                            data2 = data2[offset : offset + size]
                            patched = ''
                            for i in xrange(len(data2) / 8):
                                instruction, = unpack('Q', data2[i * 8 : i * 8 + 8])
                                if (instruction&0x9003f00002001000) == 0x0001a00000000000:
                                    instruction ^= (0x0001a00000000000 ^ 0x0000c00000000000)
                                patched += pack('Q', instruction)
                            return ''.join([data[:pos+offset], patched, data[pos + offset + size:]])
        except error:
            pass
    return data