#!/usr/bin/env python

# Requires Python 2.7+

'''
This script reads a raw HTTP request from stdin and writes to stdout
a Python script.  The generated script sends the same (or a very similar) 
request using the httplib/http.client libraries.

Certainly if you have a raw request, you could simply send it via TCP
sockets, but if for some reason the server behaves oddly with flow control,
insists on using gzip/deflate encoding, insists on using chunked encoding,
or any number of other annoying things, then using an HTTP library is a 
lot more convenient.  This script attempts to make that conversion easy.


Copyright (C) 2011-2012 Virtual Security Research, LLC
Author: Timothy D. Morgan

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU Lesser General Public License, version 3,
 as published by the Free Software Foundation.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
'''


import sys
import argparse
try:
    from lxml import etree
except:
    sys.stderr.write('ERROR: Could not import lxml module.  Ensure it is installed.\n')
    sys.stderr.write('       Under Debian, the package name is "python-lxml"\n.')
    sys.exit(1)

parser = argparse.ArgumentParser(description='Process some integers.')
parser.add_argument('requestfile', type=file, nargs='?', default=sys.stdin, 
                    help='A file containing an HTTP request.  Defaults to stdin if omitted.')
parser.add_argument('--burp', action='store_true', help='Input file is a XML export from Burp. (First request in file is used.)')
args = parser.parse_args()

if args.burp:
    safe_parser = etree.ETCompatXMLParser(resolve_entities=False)
    root = etree.parse(args.requestfile, parser=safe_parser)
    input_req = root.xpath('/items/item/request')[0].text
    root = None
else:
    input_req = args.requestfile.read()


print('''#!/usr/bin/env python

import sys
# function with either Python 2.7 or 3.x
try:
    import http.client as httpc
except:
    import httplib as httpc
''')


if '\r\n\r\n' in input_req:
    raw_headers,body = input_req.split('\r\n\r\n', 1)
elif '\n\n' in input_req:
    raw_headers,body = input_req.split('\n\n', 1)
else:
    raw_headers = input_req
    body = ''

header_lines = raw_headers.split('\n')
method,path,version = header_lines[0].split(' ', 2)

host = 'TODO'
port = 80
use_ssl = False

headers = []
for l in header_lines[1:]:
    if len(l) < 1: 
        break
    # Handle header line continuations
    if l[0] == '\t':
        if len(headers) == 0:
            continue
        name,values = headers[-1]
        values.append(l.lstrip('\t'))
        headers[-1] = (name,values)
        continue

    name,value = l.split(':',1)
    value = value.lstrip(' ').rstrip('\r')

    # Skip headers that have to do with transfer encodings and connection longevity
    if name.lower() not in ['accept','accept-language',
                            'accept-encoding','accept-charset',
                            'connection', 'keep-alive', 'host', 
                            'content-length']:
        headers.append((name,[value]))

    if name.lower() == 'host':
        if ':' in value:
            host,port = value.split(':',1)
            if port == 443:
                use_ssl = True
        else:
            host = value

print('''
# TODO: ensure the host, port, and SSL settings are correct.
host = %s
port = %s
use_ssl = %s
''' % (repr(host),repr(port),repr(use_ssl)))

chunked_body = '\n            '.join([repr(body[i:i+40]) for i in range(0,len(body),40)])

print('''
def sendRequest(connection):
    method = %s
    path = %s
    body = (%s)
    
    connection.putrequest(method, path)
    ''' % (repr(method), repr(path), chunked_body))

for name,values in headers:
    if len(values) > 1:
        continuations = ','.join([repr(v) for v in values[1:]])
        print('''    connection.putheader(%s, %s, %s)''' % (repr(name),repr(values[0]),continuations))
    else:
        print('''    connection.putheader(%s, %s)''' % (repr(name),repr(values[0])))

print('''    
    if len(body) > 0:
        connection.putheader('Content-Length', len(body))
    connection.endheaders()
    connection.send(body)
    
    return connection.getresponse()


connection = None
if use_ssl:
    connection = httpc.HTTPSConnection(host, port)
else:
    connection = httpc.HTTPConnection(host, port)

# TODO: customize code here to retrieve what you need from the response(s)
# For information on the response object's interface, see:
#   http://docs.python.org/library/httplib.html#httpresponse-objects

connection.connect()
response = sendRequest(connection)
print(response.getheaders())
print(repr(response.read()))
connection.close()
''')