Integrate a modified version of Dave Cridland's Suelta SASL library.

12 files changed, 1271 insertions, 0 deletions

diff --git a/sleekxmpp/thirdparty/__init__.py b/sleekxmpp/thirdparty/__init__.py
index 276ac3cc..3eb6ad73 100644
--- a/sleekxmpp/thirdparty/__init__.py
+++ b/sleekxmpp/thirdparty/__init__.py
@@ -2,3 +2,5 @@ try:
     from collections import OrderedDict
 except:
     from sleekxmpp.thirdparty.ordereddict import OrderedDict
+
+from sleekxmpp.thirdparty import suelta
diff --git a/sleekxmpp/thirdparty/suelta/__init__.py b/sleekxmpp/thirdparty/suelta/__init__.py
new file mode 100644
index 00000000..04f0cbad
--- /dev/null
+++ b/sleekxmpp/thirdparty/suelta/__init__.py
@@ -0,0 +1,26 @@
+# Copyright 2007-2010 David Alan Cridland
+#
+# 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.
+
+from sleekxmpp.thirdparty.suelta.saslprep import saslprep
+from sleekxmpp.thirdparty.suelta.sasl import *
+from sleekxmpp.thirdparty.suelta.mechanisms import *
+
+__version__ = '2.0'
+__version_info__ = (2, 0, 0)
diff --git a/sleekxmpp/thirdparty/suelta/exceptions.py b/sleekxmpp/thirdparty/suelta/exceptions.py
new file mode 100644
index 00000000..625cca0e
--- /dev/null
+++ b/sleekxmpp/thirdparty/suelta/exceptions.py
@@ -0,0 +1,31 @@
+class SASLError(Exception):
+
+    def __init__(self, sasl, text, mech=None):
+        """
+        :param sasl: The main `suelta.SASL` object.
+        :param text: Descpription of the error.
+        :param mech: Optional reference to the mechanism object.
+
+        :type sasl: `suelta.SASL`
+        """
+        self.sasl = sasl
+        self.text = text
+        self.mech = mech
+
+    def __str__(self):
+        if self.mech is None:
+            return 'SASL Error: %s' % self.text
+        else:
+            return 'SASL Error (%s): %s' % (self.mech, self.text)
+
+
+class SASLCancelled(SASLError):
+
+    def __init__(self, sasl, mech=None):
+        """
+        :param sasl: The main `suelta.SASL` object.
+        :param mech: Optional reference to the mechanism object.
+
+        :type sasl: `suelta.SASL`
+        """
+        super(SASLCancelled, self).__init__(sasl, "User cancelled", mech)
diff --git a/sleekxmpp/thirdparty/suelta/mechanisms/__init__.py b/sleekxmpp/thirdparty/suelta/mechanisms/__init__.py
new file mode 100644
index 00000000..5cb2ee3d
--- /dev/null
+++ b/sleekxmpp/thirdparty/suelta/mechanisms/__init__.py
@@ -0,0 +1,5 @@
+from sleekxmpp.thirdparty.suelta.mechanisms.anonymous import ANONYMOUS
+from sleekxmpp.thirdparty.suelta.mechanisms.plain import PLAIN
+from sleekxmpp.thirdparty.suelta.mechanisms.cram_md5 import CRAM_MD5
+from sleekxmpp.thirdparty.suelta.mechanisms.digest_md5 import DIGEST_MD5
+from sleekxmpp.thirdparty.suelta.mechanisms.scram_hmac import SCRAM_HMAC
diff --git a/sleekxmpp/thirdparty/suelta/mechanisms/anonymous.py b/sleekxmpp/thirdparty/suelta/mechanisms/anonymous.py
new file mode 100644
index 00000000..de89eef2
--- /dev/null
+++ b/sleekxmpp/thirdparty/suelta/mechanisms/anonymous.py
@@ -0,0 +1,36 @@
+from sleekxmpp.thirdparty.suelta.sasl import Mechanism, register_mechanism
+from sleekxmpp.thirdparty.suelta.exceptions import SASLError, SASLCancelled
+
+
+class ANONYMOUS(Mechanism):
+
+    """
+    """
+
+    def __init__(self, sasl, name):
+        """
+        """
+        super(ANONYMOUS, self).__init__(self, sasl, name, 0)
+
+    def get_values(self):
+        """
+        """
+        return {}
+
+    def process(self, challenge=None):
+        """
+        """
+        return b'Anonymous, Suelta'
+
+    def okay(self):
+        """
+        """
+        return True
+
+    def get_user(self):
+        """
+        """
+        return 'anonymous'
+
+
+register_mechanism('ANONYMOUS', 0, ANONYMOUS, use_hashes=False)
diff --git a/sleekxmpp/thirdparty/suelta/mechanisms/cram_md5.py b/sleekxmpp/thirdparty/suelta/mechanisms/cram_md5.py
new file mode 100644
index 00000000..ba44befe
--- /dev/null
+++ b/sleekxmpp/thirdparty/suelta/mechanisms/cram_md5.py
@@ -0,0 +1,63 @@
+import sys
+import hmac
+
+from sleekxmpp.thirdparty.suelta.util import hash, bytes
+from sleekxmpp.thirdparty.suelta.sasl import Mechanism, register_mechanism
+from sleekxmpp.thirdparty.suelta.exceptions import SASLError, SASLCancelled
+
+
+class CRAM_MD5(Mechanism):
+
+    """
+    """
+
+    def __init__(self, sasl, name):
+        """
+        """
+        super(CRAM_MD5, self).__init__(sasl, name, 2)
+
+        self.hash = hash(name[5:])
+        if self.hash is None:
+            raise SASLCancelled(self.sasl, self)
+        if not self.sasl.tls_active():
+            if not self.sasl.sec_query(self, 'CRAM-MD5'):
+                raise SASLCancelled(self.sasl, self)
+
+    def prep(self):
+        """
+        """
+        if 'savepass' not in self.values:
+            if self.sasl.sec_query(self, 'CLEAR-PASSWORD'):
+                self.values['savepass'] = True
+
+        if 'savepass' not in self.values:
+            del self.values['password']
+
+    def process(self, challenge):
+        """
+        """
+        if challenge is None:
+            return None
+
+        self.check_values(['username', 'password'])
+        username = bytes(self.values['username'])
+        password = bytes(self.values['password'])
+
+        mac = hmac.HMAC(key=password, digestmod=self.hash)
+
+        mac.update(challenge)
+
+        return username + b' ' + bytes(mac.hexdigest())
+
+    def okay(self):
+        """
+        """
+        return True
+
+    def get_user(self):
+        """
+        """
+        return self.values['username']
+
+
+register_mechanism('CRAM-', 20, CRAM_MD5)
diff --git a/sleekxmpp/thirdparty/suelta/mechanisms/digest_md5.py b/sleekxmpp/thirdparty/suelta/mechanisms/digest_md5.py
new file mode 100644
index 00000000..5492c553
--- /dev/null
+++ b/sleekxmpp/thirdparty/suelta/mechanisms/digest_md5.py
@@ -0,0 +1,273 @@
+import sys
+
+import random
+
+from sleekxmpp.thirdparty.suelta.util import hash, bytes, quote
+from sleekxmpp.thirdparty.suelta.sasl import Mechanism, register_mechanism
+from sleekxmpp.thirdparty.suelta.exceptions import SASLError, SASLCancelled
+
+
+
+def parse_challenge(stuff):
+    """
+    """
+    ret = {}
+    var = b''
+    val = b''
+    in_var = True
+    in_quotes = False
+    new = False
+    escaped = False
+    for c in stuff:
+        if sys.version_info >= (3, 0):
+            c = bytes([c])
+        if in_var:
+            if c.isspace():
+                continue
+            if c == b'=':
+                in_var = False
+                new = True
+            else:
+                var += c
+        else:
+            if new:
+                if c == b'"':
+                    in_quotes = True
+                else:
+                    val += c
+                new = False
+            elif in_quotes:
+                if escaped:
+                    escaped = False
+                    val += c
+                else:
+                    if c == b'\\':
+                        escaped = True
+                    elif c == b'"':
+                        in_quotes = False
+                    else:
+                        val += c
+            else:
+                if c == b',':
+                    if var:
+                        ret[var] = val
+                    var = b''
+                    val = b''
+                    in_var = True
+                else:
+                    val += c
+    if var:
+        ret[var] = val
+    return ret
+
+
+class DIGEST_MD5(Mechanism):
+
+    """
+    """
+
+    enc_magic = 'Digest session key to client-to-server signing key magic'
+    dec_magic = 'Digest session key to server-to-client signing key magic'
+
+    def __init__(self, sasl, name):
+        """
+        """
+        super(DIGEST_MD5, self).__init__(sasl, name, 3)
+
+        self.hash = hash(name[7:])
+        if self.hash is None:
+            raise SASLCancelled(self.sasl, self)
+
+        if not self.sasl.tls_active():
+            if not self.sasl.sec_query(self, '-ENCRYPTION, DIGEST-MD5'):
+                raise SASLCancelled(self.sasl, self)
+
+        self._rspauth_okay = False
+        self._digest_uri = None
+        self._a1 = None
+        self._enc_buf = b''
+        self._enc_key = None
+        self._enc_seq = 0
+        self._max_buffer = 65536
+        self._dec_buf = b''
+        self._dec_key = None
+        self._dec_seq = 0
+        self._qops = [b'auth']
+        self._qop = b'auth'
+
+    def MAC(self, seq, msg, key):
+        """
+        """
+        mac = hmac.HMAC(key=key, digestmod=self.hash)
+        seqnum = num_to_bytes(seq)
+        mac.update(seqnum)
+        mac.update(msg)
+        return mac.digest()[:10] + b'\x00\x01' + seqnum
+
+
+    def encode(self, text):
+        """
+        """
+        self._enc_buf += text
+
+    def flush(self):
+        """
+        """
+        result = b''
+        # Leave buffer space for the MAC
+        mbuf = self._max_buffer - 10 - 2 - 4
+
+        while self._enc_buf:
+            msg = self._encbuf[:mbuf]
+            mac = self.MAC(self._enc_seq, msg, self._enc_key, self.hash)
+            self._enc_seq += 1
+            msg += mac
+            result += num_to_bytes(len(msg)) + msg
+            self._enc_buf = self._enc_buf[mbuf:]
+
+        return result
+
+    def decode(self, text):
+        """
+        """
+        self._dec_buf += text
+        result = b''
+
+        while len(self._dec_buf) > 4:
+            num = bytes_to_num(self._dec_buf)
+            if len(self._dec_buf) < (num + 4):
+                return result
+
+            mac = self._dec_buf[4:4 + num]
+            self._dec_buf = self._dec_buf[4 + num:]
+            msg = mac[:-16]
+
+            mac_conf = self.MAC(self._dec_mac, msg, self._dec_key)
+            if mac[-16:] != mac_conf:
+                self._desc_sec = None
+                return result
+
+            self._dec_seq += 1
+            result += msg
+
+        return result
+
+    def response(self):
+        """
+        """
+        vitals = ['username']
+        if not self.has_values(['key_hash']):
+            vitals.append('password')
+        self.check_values(vitals)
+
+        resp = {}
+        if 'auth-int' in self._qops:
+            self._qop = b'auth-int'
+        resp['qop'] = self._qop
+        if 'realm' in self.values:
+            resp['realm'] = quote(self.values['realm'])
+
+        resp['username'] = quote(bytes(self.values['username']))
+        resp['nonce'] = quote(self.values['nonce'])
+        if self.values['nc']:
+            self._cnonce = self.values['cnonce']
+        else:
+            self._cnonce = bytes('%s' % random.random())[2:]
+        resp['cnonce'] = quote(self._cnonce)
+        self.values['nc'] += 1
+        resp['nc'] = bytes('%08x' % self.values['nc'])
+
+        service = bytes(self.sasl.service)
+        host = bytes(self.sasl.host)
+        self._digest_uri = service + b'/' + host
+        resp['digest-uri'] = quote(self._digest_uri)
+
+        a2 = b'AUTHENTICATE:' + self._digest_uri
+        if self._qop != b'auth':
+            a2 += b':00000000000000000000000000000000'
+            resp['maxbuf'] = b'16777215'  # 2**24-1
+        resp['response'] = self.gen_hash(a2)
+        return b','.join([bytes(k) + b'=' + bytes(v) for k, v in resp.items()])
+
+    def gen_hash(self, a2):
+        """
+        """
+        if not self.has_values(['key_hash']):
+            key_hash = self.hash()
+            user = bytes(self.values['username'])
+            password = bytes(self.values['password'])
+            realm = bytes(self.values['realm'])
+            kh = user + b':' + realm + b':' + password
+            key_hash.update(kh)
+            self.values['key_hash'] = key_hash.digest()
+
+        a1 = self.hash(self.values['key_hash'])
+        a1h = b':' + self.values['nonce'] + b':' + self._cnonce
+        a1.update(a1h)
+        response = self.hash()
+        self._a1 = a1.digest()
+        rv = bytes(a1.hexdigest().lower())
+        rv += b':' + self.values['nonce']
+        rv += b':' + bytes('%08x' % self.values['nc'])
+        rv += b':' + self._cnonce
+        rv += b':' + self._qop
+        rv += b':' + bytes(self.hash(a2).hexdigest().lower())
+        response.update(rv)
+        return bytes(response.hexdigest().lower())
+
+    def mutual_auth(self, cmp_hash):
+        """
+        """
+        a2 = b':' + self._digest_uri
+        if self._qop != b'auth':
+            a2 += b':00000000000000000000000000000000'
+        if self.gen_hash(a2) == cmp_hash:
+            self._rspauth_okay = True
+
+    def prep(self):
+        """
+        """
+        if 'password' in self.values:
+            del self.values['password']
+        self.values['cnonce'] = self._cnonce
+
+    def process(self, challenge=None):
+        """
+        """
+        if challenge is None:
+            if self.has_values(['username', 'realm', 'nonce', 'key_hash',
+                                'nc', 'cnonce', 'qops']):
+                self._qops = self.values['qops']
+                return self.response()
+            else:
+                return None
+
+        d = parse_challenge(challenge)
+        if b'rspauth' in d:
+            self.mutual_auth(d[b'rspauth'])
+        else:
+            if b'realm' not in d:
+                d[b'realm'] = self.sasl.def_realm
+            for key in ['nonce', 'realm']:
+                if bytes(key) in d:
+                    self.values[key] = d[bytes(key)]
+            self.values['nc'] = 0
+            self._qops = [b'auth']
+            if b'qop' in d:
+                self._qops = [x.strip() for x in d[b'qop'].split(b',')]
+            self.values['qops'] = self._qops
+            if b'maxbuf' in d:
+                self._max_buffer = int(d[b'maxbuf'])
+            return self.response()
+
+    def okay(self):
+        """
+        """
+        if self._rspauth_okay and self._qop == b'auth-int':
+            self._enc_key = self.hash(self._a1 + self.enc_magic).digest()
+            self._dec_key = self.hash(self._a1 + self.dec_magic).digest()
+            self.encoding = True
+        return self._rspauth_okay
+
+
+register_mechanism('DIGEST-', 30, DIGEST_MD5)
diff --git a/sleekxmpp/thirdparty/suelta/mechanisms/plain.py b/sleekxmpp/thirdparty/suelta/mechanisms/plain.py
new file mode 100644
index 00000000..ab17095e
--- /dev/null
+++ b/sleekxmpp/thirdparty/suelta/mechanisms/plain.py
@@ -0,0 +1,61 @@
+import sys
+
+from sleekxmpp.thirdparty.suelta.util import bytes
+from sleekxmpp.thirdparty.suelta.sasl import Mechanism, register_mechanism
+from sleekxmpp.thirdparty.suelta.exceptions import SASLError, SASLCancelled
+
+
+class PLAIN(Mechanism):
+
+    """
+    """
+
+    def __init__(self, sasl, name):
+        """
+        """
+        super(PLAIN, self).__init__(sasl, name)
+
+        if not self.sasl.tls_active():
+            if not self.sasl.sec_query(self, '-ENCRYPTION, PLAIN'):
+                raise SASLCancelled(self.sasl, self)
+        else:
+            if not self.sasl.sec_query(self, '+ENCRYPTION, PLAIN'):
+                raise SASLCancelled(self.sasl, self)
+
+        self.check_values(['username', 'password'])
+
+    def prep(self):
+        """
+        Prepare for processing by deleting the password if
+        the user has not approved storing it in the clear.
+        """
+        if 'savepass' not in self.values:
+            if self.sasl.sec_query(self, 'CLEAR-PASSWORD'):
+                self.values['savepass'] = True
+
+        if 'savepass' not in self.values:
+            del self.values['password']
+
+        return True
+
+    def process(self, challenge=None):
+        """
+        Process a challenge request and return the response.
+
+        :param challenge: A challenge issued by the server that
+                          must be answered for authentication.
+        """
+        user = bytes(self.values['username'])
+        password = bytes(self.values['password'])
+        return b'\x00' + user + b'\x00' + password
+
+    def okay(self):
+        """
+        Mutual authentication is not supported by PLAIN.
+
+        :returns: ``True``
+        """
+        return True
+
+
+register_mechanism('PLAIN', 1, PLAIN, use_hashes=False)
diff --git a/sleekxmpp/thirdparty/suelta/mechanisms/scram_hmac.py b/sleekxmpp/thirdparty/suelta/mechanisms/scram_hmac.py
new file mode 100644
index 00000000..e0020329
--- /dev/null
+++ b/sleekxmpp/thirdparty/suelta/mechanisms/scram_hmac.py
@@ -0,0 +1,176 @@
+import sys
+import hmac
+import random
+from base64 import b64encode, b64decode
+
+from sleekxmpp.thirdparty.suelta.util import hash, bytes, num_to_bytes, bytes_to_num, XOR
+from sleekxmpp.thirdparty.suelta.sasl import Mechanism, register_mechanism
+from sleekxmpp.thirdparty.suelta.exceptions import SASLError, SASLCancelled
+
+
+def parse_challenge(challenge):
+    """
+    """
+    items = {}
+    for key, value in [item.split(b'=', 1) for item in challenge.split(b',')]:
+        items[key] = value
+    return items
+
+
+class SCRAM_HMAC(Mechanism):
+
+    """
+    """
+
+    def __init__(self, sasl, name):
+        """
+        """
+        super(SCRAM_HMAC, self).__init__(sasl, name, 0)
+
+        self._cb = False
+        if name[-5:] == '-PLUS':
+            name = name[:-5]
+            self._cb = True
+
+        self.hash = hash(self.name[6:])
+        if self.hash is None:
+            raise SASLCancelled(self.sasl, self)
+        if not self.sasl.tls_active():
+            if not self.sasl.sec_query(self, '-ENCRYPTION, SCRAM'):
+                raise SASLCancelled(self.sasl, self)
+
+        self._step = 0
+        self._rspauth = False
+
+    def HMAC(self, key, msg):
+        """
+        """
+        return hmac.HMAC(key=key, msg=msg, digestmod=self.hash).digest()
+
+    def Hi(self, text, salt, iterations):
+        """
+        """
+        text = bytes(text)
+        ui_1 = self.HMAC(text, salt + b'\0\0\0\01')
+        ui = ui_1
+        for i in range(iterations - 1):
+            ui_1 = self.HMAC(text, ui_1)
+            ui = XOR(ui, ui_1)
+        return ui
+
+    def H(self, text):
+        """
+        """
+        return self.hash(text).digest()
+
+    def prep(self):
+        if 'password' in self.values:
+            del self.values['password']
+
+    def process(self, challenge=None):
+        """
+        """
+        steps = {
+            0: self.process_one,
+            1: self.process_two,
+            2: self.process_three
+        }
+        return steps[self._step](challenge)
+
+    def process_one(self, challenge):
+        """
+        """
+        vitals = ['username']
+        if 'SaltedPassword' not in self.values:
+            vitals.append('password')
+        if 'Iterations' not in self.values:
+            vitals.append('password')
+
+        self.check_values(vitals)
+
+        username = bytes(self.values['username'])
+
+        self._step = 1
+        self._cnonce = bytes(('%s' % random.random())[2:])
+        self._soup = b'n=' + username + b',r=' + self._cnonce
+        self._gs2header = b''
+
+        if not self.sasl.tls_active():
+            if self._cb:
+                self._gs2header = b'p=tls-unique,,'
+            else:
+                self._gs2header = b'y,,'
+        else:
+            self._gs2header = b'n,,'
+
+        return self._gs2header + self._soup
+
+    def process_two(self, challenge):
+        """
+        """
+        data = parse_challenge(challenge)
+
+        self._step = 2
+        self._soup += b',' + challenge + b','
+        self._nonce = data[b'r']
+        self._salt = b64decode(data[b's'])
+        self._iter = int(data[b'i'])
+
+        if self._nonce[:len(self._cnonce)] != self._cnonce:
+            raise SASLCancelled(self.sasl, self)
+
+        cbdata = self.sasl.tls_active()
+        c = self._gs2header
+        if not cbdata and self._cb:
+            c += None
+
+        r = b'c=' + b64encode(c).replace(b'\n', b'')
+        r += b',r=' + self._nonce
+        self._soup += r
+
+        if 'Iterations' in self.values:
+            if self.values['Iterations'] != self._iter:
+                if 'SaltedPassword' in self.values:
+                    del self.values['SaltedPassword']
+        if 'Salt' in self.values:
+            if self.values['Salt'] != self._salt:
+                if 'SaltedPassword' in self.values:
+                    del self.values['SaltedPassword']
+
+        self.values['Iterations'] = self._iter
+        self.values['Salt'] = self._salt
+
+        if 'SaltedPassword' not in self.values:
+            self.check_values(['password'])
+            password = bytes(self.values['password'])
+            salted_pass = self.Hi(password, self._salt, self._iter)
+            self.values['SaltedPassword'] = salted_pass
+
+        salted_pass = self.values['SaltedPassword']
+        client_key = self.HMAC(salted_pass, b'Client Key')
+        stored_key = self.H(client_key)
+        client_sig = self.HMAC(stored_key, self._soup)
+        client_proof = XOR(client_key, client_sig)
+        r += b',p=' + b64encode(client_proof).replace(b'\n', b'')
+        server_key = self.HMAC(self.values['SaltedPassword'], b'Server Key')
+        self.server_sig = self.HMAC(server_key, self._soup)
+        return r
+
+    def process_three(self, challenge=None):
+        """
+        """
+        data = parse_challenge(challenge)
+        if b64decode(data[b'v']) == self.server_sig:
+            self._rspauth = True
+
+    def okay(self):
+        """
+        """
+        return self._rspauth
+
+    def get_user(self):
+        return self.values['username']
+
+
+register_mechanism('SCRAM-', 60, SCRAM_HMAC)
+register_mechanism('SCRAM-', 70, SCRAM_HMAC, extra='-PLUS')
diff --git a/sleekxmpp/thirdparty/suelta/sasl.py b/sleekxmpp/thirdparty/suelta/sasl.py
new file mode 100644
index 00000000..ec7afe9d
--- /dev/null
+++ b/sleekxmpp/thirdparty/suelta/sasl.py
@@ -0,0 +1,402 @@
+from sleekxmpp.thirdparty.suelta.util import hashes
+from sleekxmpp.thirdparty.suelta.saslprep import saslprep
+
+#: Global session storage for user answers to requested mechanism values
+#: and security questions. This allows the user's preferences to be
+#: persisted across multiple SASL authentication attempts made by the
+#: same process.
+SESSION = {'answers': {},
+           'passwords': {},
+           'sec_queries': {},
+           'stash': {},
+           'stash_file': ''}
+
+#: Global registry mapping mechanism names to implementation classes.
+MECHANISMS = {}
+
+#: Global registry mapping mechanism names to security scores.
+MECH_SEC_SCORES = {}
+
+
+def register_mechanism(basename, basescore, impl, extra=None, use_hashes=True):
+    """
+    Add a SASL mechanism to the registry of available mechanisms.
+
+    :param basename: The base name of the mechanism type, such as ``CRAM-``.
+    :param basescore: The base security score for this type of mechanism.
+    :param impl: The class implementing the mechanism.
+    :param extra: Any additional qualifiers to the mechanism name,
+                  such as ``-PLUS``.
+    :param use_hashes: If ``True``, then register the mechanism for use with
+                       all available hashes.
+    """
+    n = 0
+    if use_hashes:
+        for hashing_alg in hashes():
+            n += 1
+            name = basename + hashing_alg
+            if extra is not None:
+                name += extra
+            MECHANISMS[name] = impl
+            MECH_SEC_SCORES[name] = basescore + n
+    else:
+        MECHANISMS[basename] = impl
+        MECH_SEC_SCORES[basename] = basescore
+
+
+def set_stash_file(filename):
+    """
+    Enable or disable storing the stash to disk.
+
+    If the filename is ``None``, then disable using a stash file.
+
+    :param filename: The path to the file to store the stash data.
+    """
+    SESSION['stash_file'] = filename
+    try:
+        import marshal
+        stash_file = file(filename)
+        SESSION['stash'] = marshal.load(stash_file)
+    except:
+        SESSION['stash'] = {}
+
+
+def sec_query_allow(mech, query):
+    """
+    Quick default to allow all feature combinations which could
+    negatively affect security.
+
+    :param mech: The chosen SASL mechanism
+    :param query: An encoding of the combination of enabled and
+                  disabled features which may affect security.
+
+    :returns: ``True``
+    """
+    return True
+
+
+class SASL(object):
+
+    """
+    """
+
+    def __init__(self, host, service, mech=None, username=None,
+                 min_sec=0, request_values=None, sec_query=None,
+                 tls_active=None, def_realm=None):
+        """
+        :param string host: The host of the service requiring authentication.
+        :param string service: The name of the underlying protocol in use.
+        :param string mech: Optional name of the SASL mechanism to use.
+                            If given, only this mechanism may be used for
+                            authentication.
+        :param string username: The username to use when authenticating.
+        :param request_values: Reference to a function for supplying
+                               values requested by mechanisms, such
+                               as passwords. (See above)
+        :param sec_query: Reference to a function for approving or
+                          denying feature combinations which could
+                          negatively impact security. (See above)
+        :param tls_active: Function for indicating if TLS has been
+                           negotiated. (See above)
+        :param integer min_sec: The minimum security level accepted. This
+                                only allows for SASL mechanisms whose
+                                security rating is greater than `min_sec`.
+        :param string def_realm: The default realm, if different than `host`.
+
+        :type request_values: :func:`request_values`
+        :type sec_query: :func:`sec_query`
+        :type tls_active: :func:`tls_active`
+        """
+        self.host = host
+        self.def_realm = def_realm or host
+        self.service = service
+        self.user = username
+        self.mech = mech
+        self.min_sec = min_sec - 1
+
+        self.request_values = request_values
+        self._sec_query = sec_query
+        if tls_active is not None:
+            self.tls_active = tls_active
+        else:
+            self.tls_active = lambda: False
+
+        self.try_username = self.user
+        self.try_password = None
+
+        self.stash_id = None
+        self.testkey = None
+
+    def reset_stash_id(self, username):
+        """
+        Reset the ID for the stash for persisting user data.
+
+        :param username: The username to base the new ID on.
+        """
+        username = saslprep(username)
+        self.user = username
+        self.try_username = self.user
+        self.testkey = [self.user, self.host, self.service]
+        self.stash_id = '\0'.join(self.testkey)
+
+    def sec_query(self, mech, query):
+        """
+        Request authorization from the user to use a combination
+        of features which could negatively affect security.
+
+        The ``sec_query`` callback when creating the SASL object will
+        be called if the query has not been answered before. Otherwise,
+        the query response will be pulled from ``SESSION['sec_queries']``.
+
+        If no ``sec_query`` callback was provided, then all queries
+        will be denied.
+
+        :param mech: The chosen SASL mechanism
+        :param query: An encoding of the combination of enabled and
+                      disabled features which may affect security.
+        :rtype: bool
+        """
+        if self._sec_query is None:
+            return False
+        if query in SESSION['sec_queries']:
+            return SESSION['sec_queries'][query]
+        resp = self._sec_query(mech, query)
+        if resp:
+            SESSION['sec_queries'][query] = resp
+
+        return resp
+
+    def find_password(self, mech):
+        """
+        Find and return the user's password, if it has been entered before
+        during this session.
+
+        :param mech: The chosen SASL mechanism.
+        """
+        if self.try_password is not None:
+            return self.try_password
+        if self.testkey is None:
+            return
+
+        testkey = self.testkey[:]
+        lockout = 1
+
+    def find_username(self):
+        """Find and return user's username if known."""
+        return self.try_username
+
+    def success(self, mech):
+        mech.preprep()
+        if 'password' in mech.values:
+            testkey = self.testkey[:]
+            while len(testkey):
+                tk = '\0'.join(testkey)
+                if tk in SESSION['passwords']:
+                    break
+                SESSION['passwords'][tk] = mech.values['password']
+                testkey = testkey[:-1]
+        mech.prep()
+        mech.save_values()
+
+    def failure(self, mech):
+        mech.clear()
+        self.testkey = self.testkey[:-1]
+
+    def choose_mechanism(self, mechs, force_plain=False):
+        """
+        Choose the most secure mechanism from a list of mechanisms.
+
+        If ``force_plain`` is given, return the ``PLAIN`` mechanism.
+
+        :param mechs: A list of mechanism names.
+        :param force_plain: If ``True``, force the selection of the
+                            ``PLAIN`` mechanism.
+        :returns: A SASL mechanism object, or ``None`` if no mechanism
+                  could be selected.
+        """
+        # Handle selection of PLAIN and ANONYMOUS
+        if force_plain:
+            return MECHANISMS['PLAIN'](self, 'PLAIN')
+
+        if self.user is not None:
+            requested_mech = '*' if self.mech is None else self.mech
+        else:
+            if self.mech is None:
+                requested_mech = 'ANONYMOUS'
+            else:
+                requested_mech = self.mech
+        if requested_mech == '*' and self.user == 'anonymous':
+            requested_mech = 'ANONYMOUS'
+
+        # If a specific mechanism was requested, try it
+        if requested_mech != '*':
+            if requested_mech in MECHANISMS and \
+               requested_mech in MECH_SEC_SCORES:
+                return MECHANISMS[requested_mech](self, requested_mech)
+            return None
+
+        # Pick the best mechanism based on its security score
+        best_score = self.min_sec
+        best_mech = None
+        for name in mechs:
+            if name in MECH_SEC_SCORES:
+                if MECH_SEC_SCORES[name] > best_score:
+                    best_score = MECH_SEC_SCORES[name]
+                    best_mech = name
+        if best_mech != None:
+            best_mech = MECHANISMS[best_mech](self, best_mech)
+
+        return best_mech
+
+
+class Mechanism(object):
+
+    """
+    """
+
+    def __init__(self, sasl, name, version=0, use_stash=True):
+        self.name = name
+        self.sasl = sasl
+        self.use_stash = use_stash
+
+        self.encoding = False
+        self.values = {}
+
+        if use_stash:
+            self.load_values()
+
+    def load_values(self):
+        """Retrieve user data from the stash."""
+        self.values = {}
+        if not self.use_stash:
+            return False
+        if self.sasl.stash_id is not None:
+            if self.sasl.stash_id in SESSION['stash']:
+                if SESSION['stash'][self.sasl.stash_id]['mech'] == self.name:
+                    values = SESSION['stash'][self.sasl.stash_id]['values']
+                    self.values.update(values)
+        if self.sasl.user is not None:
+            if not self.has_values(['username']):
+                self.values['username'] = self.sasl.user
+        return None
+
+    def save_values(self):
+        """
+        Save user data to the session stash.
+
+        If a stash file name has been set using ``SESSION['stash_file']``,
+        the saved values will be persisted to disk.
+        """
+        if not self.use_stash:
+            return False
+        if self.sasl.stash_id is not None:
+            if self.sasl.stash_id not in SESSION['stash']:
+                SESSION['stash'][self.sasl.stash_id] = {}
+            SESSION['stash'][self.sasl.stash_id]['values'] = self.values
+            SESSION['stash'][self.sasl.stash_id]['mech'] = self.name
+            if SESSION['stash_file'] not in ['', None]:
+                import marshal
+                stash_file = file(SESSION['stash_file'], 'wb')
+                marshal.dump(SESSION['stash'], stash_file)
+
+    def clear(self):
+        """Reset all user data, except the username."""
+        username = None
+        if 'username' in self.values:
+            username = self.values['username']
+        self.values = {}
+        if username is not None:
+            self.values['username'] = username
+        self.save_values()
+        self.values = {}
+        self.load_values()
+
+    def okay(self):
+        """
+        Indicate if mutual authentication has completed successfully.
+
+        :rtype: bool
+        """
+        return False
+
+    def preprep(self):
+        """Ensure that the stash ID has been set before processing."""
+        if self.sasl.stash_id is None:
+            if 'username' in self.values:
+                self.sasl.reset_stash_id(self.values['username'])
+
+    def prep(self):
+        """
+        Prepare stored values for processing.
+
+        For example, by removing extra copies of passwords from memory.
+        """
+        pass
+
+    def process(self, challenge=None):
+        """
+        Process a challenge request and return the response.
+
+        :param challenge: A challenge issued by the server that
+                          must be answered for authentication.
+        """
+        raise NotImplemented
+
+    def fulfill(self, values):
+        """
+        Provide requested values to the mechanism.
+
+        :param values: A dictionary of requested values.
+        """
+        if 'password' in values:
+            values['password'] = saslprep(values['password'])
+        self.values.update(values)
+
+    def missing_values(self, keys):
+        """
+        Return a dictionary of value names that have not been given values
+        by the user, or retrieved from the stash.
+
+        :param keys: A list of value names to check.
+        :rtype: dict
+        """
+        vals = {}
+        for name in keys:
+            if name not in self.values or self.values[name] is None:
+                if self.use_stash:
+                    if name == 'username':
+                        value = self.sasl.find_username()
+                        if value is not None:
+                            self.sasl.reset_stash_id(value)
+                            self.values[name] = value
+                            break
+                    if name == 'password':
+                        value = self.sasl.find_password(self)
+                        if value is not None:
+                            self.values[name] = value
+                            break
+                vals[name] = None
+        return vals
+
+    def has_values(self, keys):
+        """
+        Check that the given values have been retrieved from the user,
+        or from the stash.
+
+        :param keys: A list of value names to check.
+        """
+        return len(self.missing_values(keys)) == 0
+
+    def check_values(self, keys):
+        """
+        Request missing values from the user.
+
+        :param keys: A list of value names to request, if missing.
+        """
+        vals = self.missing_values(keys)
+        if vals:
+            self.sasl.request_values(self, vals)
+
+    def get_user(self):
+        """Return the username usd for this mechanism."""
+        return self.values['username']
diff --git a/sleekxmpp/thirdparty/suelta/saslprep.py b/sleekxmpp/thirdparty/suelta/saslprep.py
new file mode 100644
index 00000000..fe58d58b
--- /dev/null
+++ b/sleekxmpp/thirdparty/suelta/saslprep.py
@@ -0,0 +1,78 @@
+from __future__ import unicode_literals
+
+import sys
+import stringprep
+import unicodedata
+
+
+def saslprep(text, strict=True):
+    """
+    Return a processed version of the given string, using the SASLPrep
+    profile of stringprep.
+
+    :param text: The string to process, in UTF-8.
+    :param strict: If ``True``, prevent the use of unassigned code points.
+    """
+
+    if sys.version_info < (3, 0):
+        if type(text) == str:
+            text = text.decode('us-ascii')
+
+    # Mapping:
+    #
+    #  -  non-ASCII space characters [StringPrep, C.1.2] that can be
+    #     mapped to SPACE (U+0020), and
+    #
+    #  -  the 'commonly mapped to nothing' characters [StringPrep, B.1]
+    #     that can be mapped to nothing.
+    buffer = ''
+    for char in text:
+        if stringprep.in_table_c12(char):
+            buffer += ' '
+        elif not stringprep.in_table_b1(char):
+            buffer += char
+
+    # Normalization using form KC
+    text = unicodedata.normalize('NFKC', buffer)
+
+    # Check for bidirectional string
+    buffer = ''
+    first_is_randal = False
+    if text:
+        first_is_randal = stringprep.in_table_d1(text[0])
+        if first_is_randal and not stringprep.in_table_d1(text[-1]):
+            raise UnicodeError('Section 6.3 [end]')
+
+    # Check for prohibited characters
+    for x in range(len(text)):
+        if strict and stringprep.in_table_a1(text[x]):
+            raise UnicodeError('Unassigned Codepoint')
+        if stringprep.in_table_c12(text[x]):
+            raise UnicodeError('In table C.1.2')
+        if stringprep.in_table_c21(text[x]):
+            raise UnicodeError('In table C.2.1')
+        if stringprep.in_table_c22(text[x]):
+            raise UnicodeError('In table C.2.2')
+        if stringprep.in_table_c3(text[x]):
+            raise UnicodeError('In table C.3')
+        if stringprep.in_table_c4(text[x]):
+            raise UnicodeError('In table C.4')
+        if stringprep.in_table_c5(text[x]):
+            raise UnicodeError('In table C.5')
+        if stringprep.in_table_c6(text[x]):
+            raise UnicodeError('In table C.6')
+        if stringprep.in_table_c7(text[x]):
+            raise UnicodeError('In table C.7')
+        if stringprep.in_table_c8(text[x]):
+            raise UnicodeError('In table C.8')
+        if stringprep.in_table_c9(text[x]):
+            raise UnicodeError('In table C.9')
+        if x:
+            if first_is_randal and stringprep.in_table_d2(text[x]):
+                raise UnicodeError('Section 6.2')
+            if not first_is_randal and \
+               x != len(text) - 1 and \
+               stringprep.in_table_d1(text[x]):
+                raise UnicodeError('Section 6.3')
+
+    return text
diff --git a/sleekxmpp/thirdparty/suelta/util.py b/sleekxmpp/thirdparty/suelta/util.py
new file mode 100644
index 00000000..7d822a81
--- /dev/null
+++ b/sleekxmpp/thirdparty/suelta/util.py
@@ -0,0 +1,118 @@
+"""
+"""
+
+import sys
+import hashlib
+
+
+def bytes(text):
+    """
+    Convert Unicode text to UTF-8 encoded bytes.
+
+    Since Python 2.6+ and Python 3+ have similar but incompatible
+    signatures, this function unifies the two to keep code sane.
+
+    :param text: Unicode text to convert to bytes
+    :rtype: bytes (Python3), str (Python2.6+)
+    """
+    if sys.version_info < (3, 0):
+        import __builtin__
+        return __builtin__.bytes(text)
+    else:
+        import builtins
+        if isinstance(text, builtins.bytes):
+            # We already have bytes, so do nothing
+            return text
+        if isinstance(text, list):
+            # Convert a list of integers to bytes
+            return builtins.bytes(text)
+        else:
+            # Convert UTF-8 text to bytes
+            return builtins.bytes(text, encoding='utf-8')
+
+
+def quote(text):
+    """
+    Enclose in quotes and escape internal slashes and double quotes.
+
+    :param text: A Unicode or byte string.
+    """
+    text = bytes(text)
+    return b'"' + text.replace(b'\\', b'\\\\').replace(b'"', b'\\"') + b'"'
+
+
+def num_to_bytes(num):
+    """
+    Convert an integer into a four byte sequence.
+
+    :param integer num: An integer to convert to its byte representation.
+    """
+    bval = b''
+    bval += bytes(chr(0xFF & (num >> 24)))
+    bval += bytes(chr(0xFF & (num >> 16)))
+    bval += bytes(chr(0xFF & (num >> 8)))
+    bval += bytes(chr(0xFF & (num >> 0)))
+    return bval
+
+
+def bytes_to_num(bval):
+    """
+    Convert a four byte sequence to an integer.
+
+    :param bytes bval: A four byte sequence to turn into an integer.
+    """
+    num = 0
+    num += ord(bval[0] << 24)
+    num += ord(bval[1] << 16)
+    num += ord(bval[2] << 8)
+    num += ord(bval[3])
+    return num
+
+
+def XOR(x, y):
+    """
+    Return the results of an XOR operation on two equal length byte strings.
+
+    :param bytes x: A byte string
+    :param bytes y: A byte string
+    :rtype: bytes
+    """
+    result = b''
+    for a, b in zip(x, y):
+        if sys.version_info < (3, 0):
+            result += chr((ord(a) ^ ord(b)))
+        else:
+            result += bytes([a ^ b])
+    return result
+
+
+def hash(name):
+    """
+    Return a hash function implementing the given algorithm.
+
+    :param name: The name of the hashing algorithm to use.
+    :type name: string
+
+    :rtype: function
+    """
+    name = name.lower()
+    if name.startswith('sha-'):
+        name = 'sha' + name[4:]
+    if name in dir(hashlib):
+        return getattr(hashlib, name)
+    return None
+
+
+def hashes():
+    """
+    Return a list of available hashing algorithms.
+
+    :rtype: list of strings
+    """
+    t = []
+    if 'md5' in dir(hashlib):
+        t = ['MD5']
+    if 'md2' in dir(hashlib):
+        t += ['MD2']
+    hashes = ['SHA-' + h[3:] for h in dir(hashlib) if h.startswith('sha')]
+    return t + hashes