Add server-side otp preauth plugin

This plugin implements the proposal for providing OTP support by
proxying requests to RADIUS. Details can be found inside the
provided documentation as well as on the project page.

http://k5wiki.kerberos.org/wiki/Projects/OTPOverRADIUS

ticket: 7678

1 files changed, 226 insertions, 0 deletions

diff --git a/src/tests/t_otp.py b/src/tests/t_otp.py
new file mode 100644
index 0000000000..66a03ee573
--- /dev/null
+++ b/src/tests/t_otp.py
@@ -0,0 +1,226 @@
+#!/usr/bin/python
+#
+# Author: Nathaniel McCallum <npmccallum@redhat.com>
+#
+# Copyright (c) 2013 Red Hat, Inc.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+
+#
+# This script tests OTP, both UDP and Unix Sockets, with a variety of
+# configuration. It requires pyrad to run, but exits gracefully if not found.
+# It also deliberately shuts down the test daemons between tests in order to
+# test how OTP handles the case of short daemon restarts.
+#
+
+from Queue import Empty
+import StringIO
+import struct
+import subprocess
+import sys
+import socket
+import os
+import atexit
+
+try:
+    from pyrad import packet, dictionary
+    from multiprocessing import Process, Queue
+except ImportError:
+    success('Warning: skipping OTP tests due to missing pyrad or old Python')
+    exit(0)
+
+from k5test import *
+
+class RadiusDaemon(Process):
+    MAX_PACKET_SIZE = 4096
+
+    # We could use a dictionary file, but since we need
+    # such few attributes, we'll just include them here
+    DICTIONARY = dictionary.Dictionary(StringIO.StringIO("""
+ATTRIBUTE    User-Name    1    string
+ATTRIBUTE    User-Password   2    string
+ATTRIBUTE    NAS-Identifier  32    string
+"""))
+
+    def listen(self, addr):
+        raise NotImplementedError()
+
+    def recvRequest(self, data):
+        raise NotImplementedError()
+
+    def run(self):
+        addr = self._args[0]
+        secr = self._args[1]
+        pswd = self._args[2]
+        outq = self._args[3]
+
+        if secr:
+            with open(secr) as file:
+                secr = file.read().strip()
+
+        data = self.listen(addr)
+        outq.put("started")
+        (buf, sock, addr) = self.recvRequest(data)
+        pkt = packet.AuthPacket(secret=secr,
+                                dict=RadiusDaemon.DICTIONARY,
+                                packet=buf)
+
+        usernm = []
+        passwd = []
+        for key in pkt.keys():
+            if key == 'User-Password':
+                passwd = map(pkt.PwDecrypt, pkt[key])
+            elif key == 'User-Name':
+                usernm = pkt[key]
+
+        reply = pkt.CreateReply()
+        replyq = {'user': usernm, 'pass': passwd}
+        if passwd == [pswd]:
+            reply.code = packet.AccessAccept
+            replyq['reply'] = True
+        else:
+            reply.code = packet.AccessReject
+            replyq['reply'] = False
+
+        outq.put(replyq)
+        if addr is None:
+            sock.send(reply.ReplyPacket())
+        else:
+            sock.sendto(reply.ReplyPacket(), addr)
+        sock.close()
+
+class UDPRadiusDaemon(RadiusDaemon):
+    def listen(self, addr):
+        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        sock.bind((addr.split(':')[0], int(addr.split(':')[1])))
+        return sock
+
+    def recvRequest(self, sock):
+        (buf, addr) = sock.recvfrom(RadiusDaemon.MAX_PACKET_SIZE)
+        return (buf, sock, addr)
+
+class UnixRadiusDaemon(RadiusDaemon):
+    def listen(self, addr):
+        sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+        if os.path.exists(addr):
+            os.remove(addr)
+        sock.bind(addr)
+        sock.listen(1)
+        return (sock, addr)
+
+    def recvRequest(self, (sock, addr)):
+        conn = sock.accept()[0]
+        sock.close()
+        os.remove(addr)
+
+        buf = ""
+        remain = RadiusDaemon.MAX_PACKET_SIZE
+        while True:
+            buf += conn.recv(remain)
+            remain = RadiusDaemon.MAX_PACKET_SIZE - len(buf)
+            if (len(buf) >= 4):
+                remain = struct.unpack("!BBH", buf[0:4])[2] - len(buf)
+                if (remain <= 0):
+                    return (buf, conn, None)
+
+def verify(daemon, queue, reply, usernm, passwd):
+    try:
+        data = queue.get(timeout=1)
+    except Empty:
+        sys.stderr.write("ERROR: Packet not received by daemon!\n")
+        daemon.terminate()
+        sys.exit(1)
+    assert data['reply'] is reply
+    assert data['user'] == [usernm]
+    assert data['pass'] == [passwd]
+    daemon.join()
+
+def setstr(princ, type, username=None):
+    cmd = 'setstr %s otp "[{""type"": ""%s""' % (princ, type)
+    if username is None:
+        cmd += '}]"'
+    else:
+        cmd += ', ""username"": ""%s""}]"' % username
+    return cmd
+
+prefix = "/tmp/%d" % os.getpid()
+secret_file = prefix + ".secret"
+socket_file = prefix + ".socket"
+with open(secret_file, "w") as file:
+    file.write("otptest")
+atexit.register(lambda: os.remove(secret_file))
+
+conf = {'plugins': {'kdcpreauth': {'enable_only': 'otp'}},
+        'otp': {'udp': {'server': '127.0.0.1:$port9',
+                        'secret': secret_file,
+                        'strip_realm': 'true'},
+                'unix': {'server': socket_file,
+                         'strip_realm': 'false'}}}
+
+queue = Queue()
+
+realm = K5Realm(kdc_conf=conf)
+realm.run_kadminl('modprinc +requires_preauth %s' % realm.user_princ)
+flags = ['-T', realm.ccache]
+server_addr = '127.0.0.1:' + str(realm.portbase + 9)
+
+## Test UDP fail / custom username
+daemon = UDPRadiusDaemon(args=(server_addr, secret_file, 'accept', queue))
+daemon.start()
+queue.get()
+realm.run_kadminl(setstr(realm.user_princ, 'udp', 'custom'))
+realm.kinit(realm.user_princ, 'reject', flags=flags, expected_code=1)
+verify(daemon, queue, False, 'custom', 'reject')
+
+## Test UDP success / standard username
+daemon = UDPRadiusDaemon(args=(server_addr, secret_file, 'accept', queue))
+daemon.start()
+queue.get()
+realm.run_kadminl(setstr(realm.user_princ, 'udp'))
+realm.kinit(realm.user_princ, 'accept', flags=flags)
+verify(daemon, queue, True, realm.user_princ.split('@')[0], 'accept')
+
+# Detect upstream pyrad bug
+#   https://github.com/wichert/pyrad/pull/18
+try:
+    auth = packet.Packet.CreateAuthenticator()
+    packet.Packet(authenticator=auth, secret="").ReplyPacket()
+except AssertionError:
+    success('Warning: skipping UNIX domain socket tests because of pyrad '
+            'assertion bug')
+    exit(0)
+
+## Test Unix fail / custom username
+daemon = UnixRadiusDaemon(args=(socket_file, '', 'accept', queue))
+daemon.start()
+queue.get()
+realm.run_kadminl(setstr(realm.user_princ, 'unix', 'custom'))
+realm.kinit(realm.user_princ, 'reject', flags=flags, expected_code=1)
+verify(daemon, queue, False, 'custom', 'reject')
+
+## Test Unix success / standard username
+daemon = UnixRadiusDaemon(args=(socket_file, '', 'accept', queue))
+daemon.start()
+queue.get()
+realm.run_kadminl(setstr(realm.user_princ, 'unix'))
+realm.kinit(realm.user_princ, 'accept', flags=flags)
+verify(daemon, queue, True, realm.user_princ, 'accept')
+
+success('OTP tests')