flashproxy-reg-url

#!/usr/bin/env python
"""Register with a facilitator using an indirect URL."""

import base64
import getopt
import sys
import urllib
import urlparse

from flashproxy.keys import DEFAULT_FACILITATOR_PUBKEY_PEM
from flashproxy.util import parse_addr_spec, format_addr

try:
    from M2Crypto import BIO, RSA
except ImportError:
    # Defer the error reporting so that --help works even without M2Crypto.
    RSA = None

DEFAULT_REMOTE_ADDRESS = ""
DEFAULT_REMOTE_PORT = 9000
DEFAULT_FACILITATOR_URL = "https://fp-facilitator.org/"
DEFAULT_TRANSPORT = "websocket"

class options(object):
    facilitator_url = None
    facilitator_pubkey_filename = None
    transport = DEFAULT_TRANSPORT

def usage(f = sys.stdout):
    print >> f, """\
Usage: %(progname)s REMOTE[:PORT]
Print a URL, which, when retrieved, will cause the client address
REMOTE[:PORT] to be registered with the flash proxy facilitator. The
default PORT is %(port)d.

  -f, --facilitator=URL  register with the given facilitator
                           (default "%(fac_url)s").
      --facilitator-pubkey=FILENAME
                         encrypt registrations to the given PEM-formatted
                           public key (default built-in).
  -h, --help             show this help.
      --transport=TRANSPORT  register using the given transport
                           (default "%(transport)s").\
""" % {
    "progname": sys.argv[0],
    "fac_url": DEFAULT_FACILITATOR_URL,
    "port": DEFAULT_REMOTE_PORT,
    "transport": DEFAULT_TRANSPORT,
}

def build_reg(addr, transport):
    return urllib.urlencode((
        ("client", format_addr(addr)),
        ("client-transport", transport),
    ))

def get_facilitator_pubkey():
    if options.facilitator_pubkey_filename is not None:
        return RSA.load_pub_key(options.facilitator_pubkey_filename)
    else:
        return RSA.load_pub_key_bio(BIO.MemoryBuffer(DEFAULT_FACILITATOR_PUBKEY_PEM))

options.facilitator_url = DEFAULT_FACILITATOR_URL

opt, args = getopt.gnu_getopt(sys.argv[1:], "f:h", [
    "facilitator=",
    "facilitator-pubkey=",
    "help",
    "transport=",
])
for o, a in opt:
    if o == "-f" or o == "--facilitator":
        options.facilitator_url = a
    elif o == "--facilitator-pubkey":
        options.facilitator_pubkey_filename = a
    elif o == "-h" or o == "--help":
        usage()
        sys.exit()
    elif o == "--transport":
        options.transport = a

if len(args) != 1:
    usage(sys.stderr)
    sys.exit(1)

remote_addr = parse_addr_spec(args[0], DEFAULT_REMOTE_ADDRESS, DEFAULT_REMOTE_PORT)
if not remote_addr[0]:
    print >> sys.stderr, "An IP address (not just a port) is required."
    sys.exit(1)

if RSA is None:
    print >> sys.stderr, """\
This program requires the M2Crypto library, which is not installed.

You can install it using one of the packages at
http://chandlerproject.org/Projects/MeTooCrypto#Downloads.

On Debian-like systems, use the command "apt-get install python-m2crypto".\
"""
    sys.exit(1)

reg_plain = build_reg(remote_addr, options.transport)
rsa = get_facilitator_pubkey()
reg_crypt = rsa.public_encrypt(reg_plain, RSA.pkcs1_oaep_padding)
reg = base64.urlsafe_b64encode(reg_crypt)

print urlparse.urljoin(options.facilitator_url, "reg/" + reg)