source: fedd/fedd/util.py @ f069052

#!/usr/local/bin/python

import logging

from M2Crypto import SSL
from fedid import fedid

class fedd_ssl_context(SSL.Context):
    """
    Simple wrapper around an M2Crypto.SSL.Context to initialize it for fedd.
    """
    def __init__(self, my_cert, trusted_certs=None, password=None):
        """
        construct a fedd_ssl_context

        @param my_cert: PEM file with my certificate in it
        @param trusted_certs: PEM file with trusted certs in it (optional)
        """
        SSL.Context.__init__(self)

        # load_cert takes a callback to get a password, not a password, so if
        # the caller provided a password, this creates a nonce callback using a
        # lambda form.
        if password != None and not callable(password):
            # This is cute.  password = lambda *args: password produces a
            # function object that returns itself rather than one that returns
            # the object itself.  This is because password is an object
            # reference and after the assignment it's a lambda.  So we assign
            # to a temp.
            pwd = password
            password =lambda *args: pwd

        if password != None:
            self.load_cert(my_cert, callback=password)
        else:
            self.load_cert(my_cert)

        # If no trusted certificates are specified, allow unknown CAs.
        if trusted_certs: 
            self.load_verify_locations(trusted_certs)
            self.set_verify(SSL.verify_peer, 10)
        else:
            self.set_verify(SSL.verify_peer, 10, 
                callback=SSL.cb.ssl_verify_callback_allow_unknown_ca)

def pack_id(id):
    """
    Return a dictionary with the field name set by the id type.  Handy for
    creating dictionaries to be converted to messages.
    """
    if isinstance(id, fedid): return { 'fedid': id }
    elif id.startswith("http:") or id.startswith("https:"): return { 'uri': id }
    else: return { 'localname': id}

def unpack_id(id):
    """return id as a type determined by the key"""
    for k in ("localname", "fedid", "uri", "kerberosUsername"):
        if id.has_key(k): return id[k]
    return None

def set_log_level(config, sect, log):
    """ Set the logging level to the value passed in sect of config."""
    # The getattr sleight of hand finds the logging level constant
    # corrersponding to the string.  We're a little paranoid to avoid user
    # mayhem.
    if config.has_option(sect, "log_level"):
        level_str = config.get(sect, "log_level")
        try:
            level = int(getattr(logging, level_str.upper(), -1))

            if  logging.DEBUG <= level <= logging.CRITICAL:
                log.setLevel(level)
            else:
                log.error("Bad experiment_log value: %s" % level_str)

        except ValueError:
            log.error("Bad experiment_log value: %s" % level_str)