import binascii import json import logging import urlparse import requests import srp from PyQt4 import QtCore from leap.base import constants as baseconstants logger = logging.getLogger(__name__) SIGNUP_TIMEOUT = getattr(baseconstants, 'SIGNUP_TIMEOUT', 5) # XXX remove me!! SERVER = "http://springbok/1" """ Registration and authentication classes for the SRP auth mechanism used in the leap platform. We're currently using the (pure python?) srp library since it seemed the fastest way of getting something working. In the future we can switch to use python-gnutls, since libgnutls implements srp protocol. """ class LeapSRPRegister(object): def __init__(self, schema="https", provider=None, port=None, register_path="1/users.json", method="POST", fetcher=requests, srp=srp, hashfun=srp.SHA256, ng_constant=srp.NG_1024): self.schema = schema self.provider = provider self.port = port self.register_path = register_path self.method = method self.fetcher = fetcher self.srp = srp self.HASHFUN = hashfun self.NG = ng_constant self.init_session() def init_session(self): self.session = self.fetcher.session() def get_registration_uri(self): # XXX assert is https! # use urlparse if self.port: uri = "%s://%s:%s/%s" % ( self.schema, self.provider, self.port, self.register_path) else: uri = "%s://%s/%s" % ( self.schema, self.provider, self.register_path) return uri def register_user(self, username, password, keep=False): """ @rtype: tuple @rparam: (ok, request) """ salt, vkey = self.srp.create_salted_verification_key( username, password, self.HASHFUN, self.NG) user_data = { 'user[login]': username, 'user[password_verifier]': binascii.hexlify(vkey), 'user[password_salt]': binascii.hexlify(salt)} uri = self.get_registration_uri() logger.debug('post to uri: %s' % uri) # XXX get self.method req = self.session.post( uri, data=user_data, timeout=SIGNUP_TIMEOUT) logger.debug(req) logger.debug('user_data: %s', user_data) #logger.debug('response: %s', req.text) # we catch it in the form #req.raise_for_status() return (req.ok, req) class SRPAuthenticationError(Exception): """ exception raised for authentication errors """ pass safe_unhexlify = lambda x: binascii.unhexlify(x) \ if (len(x) % 2 == 0) else binascii.unhexlify('0' + x) class SRPAuth(requests.auth.AuthBase): def __init__(self, username, password): self.username = username self.password = password # XXX init something similar to # SERVER... self.init_data = None self.session = requests.session() self.init_srp() def get_data(self, response): return json.loads(response.content) def init_srp(self): usr = srp.User( self.username, self.password, srp.SHA256, srp.NG_1024) uname, A = usr.start_authentication() self.srp_usr = usr self.A = A def get_auth_data(self): return { 'login': self.username, 'A': binascii.hexlify(self.A) } def get_init_data(self): init_session = self.session.post( SERVER + '/sessions', data=self.get_auth_data()) self.init_data = self.get_data(init_session) return self.init_data def authenticate(self): print 'start authentication...' init_data = self.get_init_data() salt = init_data.get('salt', None) B = init_data.get('B', None) if not salt or not B: raise SRPAuthenticationError self.M = self.srp_usr.process_challenge( safe_unhexlify(salt), safe_unhexlify(B) ) auth_result = self.session.put( SERVER + '/sessions/' + self.username, data={'client_auth': binascii.hexlify(self.M)}) # XXX check for errors auth_data = self.get_data(auth_result) self.srp_usr.verify_session( safe_unhexlify(auth_data["M2"])) try: assert self.srp_usr.authenticated() print 'user is authenticated!' except (AssertionError): raise SRPAuthenticationError def __call__(self, req): self.authenticate() req.session = self.session return req def srpauth_protected(user=None, passwd=None): """ decorator factory that accepts user and password keyword arguments and add those to the decorated request """ def srpauth(fn, user=user, passwd=passwd): def wrapper(*args, **kwargs): print 'uri is ', args[0] if user and passwd: auth = SRPAuth(user, passwd) kwargs['auth'] = auth return fn(*args, **kwargs) return wrapper return srpauth def magic_srpauth(fn): """ decorator that gets user and password from the config file and adds those to the decorated request """ # TODO --- finish this... # currently broken. def wrapper(*args, **kwargs): uri = args[0] # XXX Ugh! # Problem with this approach. # This won't work when we're using # api.foo.bar # Unless we keep a table with the # equivalencies... domain = urlparse.urlparse(uri).netloc # XXX check this settings init... settings = QtCore.QSettings() user = settings.get('%s_username' % domain, None) # uh... I forgot. # get secret? # leapkeyring.get_password(foo?) passwd = settings.get('%s_password' % domain, None) auth = SRPAuth(user, passwd) kwargs['auth'] = auth return fn(*args, **kwargs) return wrapper if __name__ == "__main__": import sys user = sys.argv[1] passwd = sys.argv[2] @srpauth_protected(user=user, passwd=passwd) def test_srp_protected_get(*args, **kwargs): req = requests.get(*args, **kwargs) req.raise_for_status #print req.content test_srp_protected_get('http://springbok/1/cert')