1 files changed, 79 insertions, 0 deletions
diff --git a/fap/dhcpd/module_craft_option.py b/fap/dhcpd/module_craft_option.py
new file mode 100755
index 0000000..35e7328
--- /dev/null
+++ b/fap/dhcpd/module_craft_option.py
@@ -0,0 +1,79 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+'''
+    Created by Jonas 'j' Lindstad for The Gathering 2015
+    License: GPLv3
+    
+    Class used to craft byte hex encoded DHCP options
+    
+    NB: No direct support for suboptions. Should be possible to craft suboptions as
+    options, and inject them with craft_option(<option>).raw_hes(<conconcatenated options>)
+    
+    Usage examples:
+    craft_option.debug = True
+    print(craft_option(1).string('vg.no'))
+    print(craft_option(2).bytes(b'abcd'))
+    print(craft_option(3).bytes(socket.inet_aton('192.168.0.55')))
+    print(craft_option(4).bytes(b'\xde\xad\xbe\xef\xfe\xed'))
+    print(craft_option(5).raw_hex(b'\x72\x78'))
+    print(craft_option(6).ip('255.255.128.0'))
+'''
+
+from binascii import hexlify, unhexlify
+
+class craft_option(object):
+    # content = b'' # content will be stored as hex values like hex(10) + hex(255) =  0aff
+    debug = False
+    def __init__(self, code):
+        self.code = self.__int_to_pad_byte(code)
+
+    # Works as intended
+    # internal function. Converts int(3) to str('03'), int('11') to str('0b'), int(255) to str('ff')
+    def __int_to_pad_byte(self, integer):
+        return hex(integer).split('x')[1].rjust(2, '0').encode()
+
+    # Works as intended
+    def string(self, string):
+        self.method = 'string'
+        self.content = hexlify(string.encode())
+        return self.process()
+
+    # Works as intended
+    def bytes(self, bytes):
+        self.method = 'bytes'
+        self.content = hexlify(bytes)
+        return self.process()
+        
+    # Works as intended
+    # str('10.20.30.40') to b'\x10\x20\x30\x40'
+    def ip(self, ip):
+        self.method = 'ip'
+        self.content = ''.join([hex(int(i))[2:].rjust(2, '0') for i in ip.split('.')]).encode()
+        return self.process()
+
+    # Works as intended
+    # string like '\x72\x78' for 'rx'
+    def raw_hex(self, raw_hex):
+        self.method = 'raw_hex'
+        self.content = hexlify(raw_hex)
+        return self.process()
+
+
+
+    # TODO Does not work as intended
+    # int(666) to b'\x02\x9A'
+    def integer(self, integer):
+        self.method = 'integer'
+        self.content = ''.join([hex(int(i))[2:].rjust(2, '0') for i in ip.split('.')])
+        return self.process()
+        
+    def process(self):
+        length = self.__int_to_pad_byte(len(unhexlify(self.content)))
+        if self.debug is True:
+            print('----------')
+            print(self.method + '():')
+            print(self.code + length)
+            print(b'content: ' + self.content)
+            print(unhexlify(self.content))
+        return unhexlify(self.code + length + self.content)