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authorkali <kali@leap.se>2013-02-15 09:31:51 +0900
committerkali <kali@leap.se>2013-02-15 09:31:51 +0900
commit9cea9c8a34343f8792d65b96f93ae22bd8685878 (patch)
tree9f512367b1d47ced5614702a00f3ff0a8fe746d7 /src/leap/base/auth.py
parent7159734ec6c0b76fc7f3737134cd22fdaaaa7d58 (diff)
parent1032e07a50c8bb265ff9bd31b3bb00e83ddb451e (diff)
Merge branch 'release/v0.2.0'
Conflicts: README.txt
Diffstat (limited to 'src/leap/base/auth.py')
-rw-r--r--src/leap/base/auth.py355
1 files changed, 355 insertions, 0 deletions
diff --git a/src/leap/base/auth.py b/src/leap/base/auth.py
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+import binascii
+import json
+import logging
+#import urlparse
+
+import requests
+import srp
+
+from PyQt4 import QtCore
+
+from leap.base import constants as baseconstants
+from leap.crypto import leapkeyring
+from leap.util.misc import null_check
+from leap.util.web import get_https_domain_and_port
+
+logger = logging.getLogger(__name__)
+
+SIGNUP_TIMEOUT = getattr(baseconstants, 'SIGNUP_TIMEOUT', 5)
+
+"""
+Registration and authentication classes for the
+SRP auth mechanism used in the leap platform.
+
+We're using the srp library which uses a c-based implementation
+of the protocol if the c extension is available, and a python-based
+one if not.
+"""
+
+
+class SRPAuthenticationError(Exception):
+ """
+ exception raised
+ for authentication errors
+ """
+
+
+safe_unhexlify = lambda x: binascii.unhexlify(x) \
+ if (len(x) % 2 == 0) else binascii.unhexlify('0' + x)
+
+
+class LeapSRPRegister(object):
+
+ def __init__(self,
+ schema="https",
+ provider=None,
+ verify=True,
+ register_path="1/users",
+ method="POST",
+ fetcher=requests,
+ srp=srp,
+ hashfun=srp.SHA256,
+ ng_constant=srp.NG_1024):
+
+ null_check(provider, "provider")
+
+ self.schema = schema
+
+ domain, port = get_https_domain_and_port(provider)
+ self.provider = domain
+ self.port = port
+
+ self.verify = verify
+ 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,
+ verify=self.verify)
+ # we catch it in the form
+ #req.raise_for_status()
+ return (req.ok, req)
+
+
+class SRPAuth(requests.auth.AuthBase):
+
+ def __init__(self, username, password, server=None, verify=None):
+ # sanity check
+ null_check(server, 'server')
+ self.username = username
+ self.password = password
+ self.server = server
+ self.verify = verify
+
+ logger.debug('SRPAuth. verify=%s' % verify)
+ logger.debug('server: %s. username=%s' % (server, username))
+
+ self.init_data = None
+ self.session = requests.session()
+
+ self.init_srp()
+
+ 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):
+ try:
+ init_session = self.session.post(
+ self.server + '/1/sessions/',
+ data=self.get_auth_data(),
+ verify=self.verify)
+ except requests.exceptions.ConnectionError:
+ raise SRPAuthenticationError(
+ "No connection made (salt).")
+ except:
+ raise SRPAuthenticationError(
+ "Unknown error (salt).")
+ if init_session.status_code not in (200, ):
+ raise SRPAuthenticationError(
+ "No valid response (salt).")
+
+ self.init_data = init_session.json
+ return self.init_data
+
+ def get_server_proof_data(self):
+ try:
+ auth_result = self.session.put(
+ #self.server + '/1/sessions.json/' + self.username,
+ self.server + '/1/sessions/' + self.username,
+ data={'client_auth': binascii.hexlify(self.M)},
+ verify=self.verify)
+ except requests.exceptions.ConnectionError:
+ raise SRPAuthenticationError(
+ "No connection made (HAMK).")
+
+ if auth_result.status_code not in (200, ):
+ raise SRPAuthenticationError(
+ "No valid response (HAMK).")
+
+ self.auth_data = auth_result.json
+ return self.auth_data
+
+ def authenticate(self):
+ logger.debug('start authentication...')
+
+ init_data = self.get_init_data()
+ salt = init_data.get('salt', None)
+ B = init_data.get('B', None)
+
+ # XXX refactor this function
+ # move checks and un-hex
+ # to routines
+
+ if not salt or not B:
+ raise SRPAuthenticationError(
+ "Server did not send initial data.")
+
+ try:
+ unhex_salt = safe_unhexlify(salt)
+ except TypeError:
+ raise SRPAuthenticationError(
+ "Bad data from server (salt)")
+ try:
+ unhex_B = safe_unhexlify(B)
+ except TypeError:
+ raise SRPAuthenticationError(
+ "Bad data from server (B)")
+
+ self.M = self.srp_usr.process_challenge(
+ unhex_salt,
+ unhex_B
+ )
+
+ proof_data = self.get_server_proof_data()
+
+ HAMK = proof_data.get("M2", None)
+ if not HAMK:
+ errors = proof_data.get('errors', None)
+ if errors:
+ logger.error(errors)
+ raise SRPAuthenticationError("Server did not send HAMK.")
+
+ try:
+ unhex_HAMK = safe_unhexlify(HAMK)
+ except TypeError:
+ raise SRPAuthenticationError(
+ "Bad data from server (HAMK)")
+
+ self.srp_usr.verify_session(
+ unhex_HAMK)
+
+ try:
+ assert self.srp_usr.authenticated()
+ logger.debug('user is authenticated!')
+ except (AssertionError):
+ raise SRPAuthenticationError(
+ "Auth verification failed.")
+
+ def __call__(self, req):
+ self.authenticate()
+ req.cookies = self.session.cookies
+ return req
+
+
+def srpauth_protected(user=None, passwd=None, server=None, verify=True):
+ """
+ decorator factory that accepts
+ user and password keyword arguments
+ and add those to the decorated request
+ """
+ def srpauth(fn):
+ def wrapper(*args, **kwargs):
+ if user and passwd:
+ auth = SRPAuth(user, passwd, server, verify)
+ kwargs['auth'] = auth
+ kwargs['verify'] = verify
+ if not args:
+ logger.warning('attempting to get from empty uri!')
+ return fn(*args, **kwargs)
+ return wrapper
+ return srpauth
+
+
+def get_leap_credentials():
+ settings = QtCore.QSettings()
+ full_username = settings.value('username')
+ username, domain = full_username.split('@')
+ seed = settings.value('%s_seed' % domain, None)
+ password = leapkeyring.leap_get_password(full_username, seed=seed)
+ return (username, password)
+
+
+# XXX TODO
+# Pass verify as single argument,
+# in srpauth_protected style
+
+def magick_srpauth(fn):
+ """
+ decorator that gets user and password
+ from the config file and adds those to
+ the decorated request
+ """
+ logger.debug('magick srp auth decorator called')
+
+ 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...
+ user, passwd = get_leap_credentials()
+
+ # XXX pass verify and server too
+ # (pop)
+ auth = SRPAuth(user, passwd)
+ kwargs['auth'] = auth
+ return fn(*args, **kwargs)
+ return wrapper
+
+
+if __name__ == "__main__":
+ """
+ To test against test_provider (twisted version)
+ Register an user: (will be valid during the session)
+ >>> python auth.py add test password
+
+ Test login with that user:
+ >>> python auth.py login test password
+ """
+
+ import sys
+
+ if len(sys.argv) not in (4, 5):
+ print 'Usage: auth <add|login> <user> <pass> [server]'
+ sys.exit(0)
+
+ action = sys.argv[1]
+ user = sys.argv[2]
+ passwd = sys.argv[3]
+
+ if len(sys.argv) == 5:
+ SERVER = sys.argv[4]
+ else:
+ SERVER = "https://localhost:8443"
+
+ if action == "login":
+
+ @srpauth_protected(
+ user=user, passwd=passwd, server=SERVER, verify=False)
+ def test_srp_protected_get(*args, **kwargs):
+ req = requests.get(*args, **kwargs)
+ req.raise_for_status
+ return req
+
+ #req = test_srp_protected_get('https://localhost:8443/1/cert')
+ req = test_srp_protected_get('%s/1/cert' % SERVER)
+ #print 'cert :', req.content[:200] + "..."
+ print req.content
+ sys.exit(0)
+
+ if action == "add":
+ auth = LeapSRPRegister(provider=SERVER, verify=False)
+ auth.register_user(user, passwd)