118 lines
4.5 KiB
Python
118 lines
4.5 KiB
Python
import base64, hashlib, hmac, uuid
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from src import ModuleManager, utils
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from . import scram
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def _validate(self, s):
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mechanism, _, arguments = s.partition(" ")
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return {"mechanism": mechanism, "args": arguments}
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def _scram_nonce():
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return str(uuid.uuid4().hex)
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def _scram_escape(s):
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return s.replace("=", "=3D").replace(",", "=2C")
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def _scram_unescape(s):
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return s.replace("=3D", "=").replace("=2C", ",")
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def _scram_xor(s1, s2):
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return bytes(a ^ b for a, b in zip(s1, s2))
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@utils.export("serverset", {"setting": "sasl",
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"help": "Set the sasl username/password for this server",
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"validate": _validate})
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class Module(ModuleManager.BaseModule):
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@utils.hook("received.cap.ls")
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def on_cap(self, event):
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has_sasl = "sasl" in event["capabilities"]
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our_sasl = event["server"].get_setting("sasl", None)
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do_sasl = False
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if has_sasl and our_sasl:
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if not event["capabilities"]["sasl"] == None:
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our_mechanism = our_sasl["mechanism"].upper()
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do_sasl = our_mechanism in event["capabilities"
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]["sasl"].split(",")
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else:
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do_sasl = True
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if do_sasl:
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event["server"].queue_capability("sasl")
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@utils.hook("received.cap.ack")
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@utils.hook("received.cap.new")
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def on_cap_ack(self, event):
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if "sasl" in event["capabilities"]:
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sasl = event["server"].get_setting("sasl")
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event["server"].send_authenticate(sasl["mechanism"].upper())
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event["server"].wait_for_capability("sasl")
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@utils.hook("received.authenticate")
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def on_authenticate(self, event):
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sasl = event["server"].get_setting("sasl")
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mechanism = sasl["mechanism"].upper()
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auth_text = None
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if mechanism == "PLAIN":
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if event["message"] != "+":
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event["server"].send_authenticate("*")
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else:
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sasl_username, sasl_password = sasl["args"].split(":", 1)
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auth_text = ("%s\0%s\0%s" % (
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sasl_username, sasl_username, sasl_password)).encode("utf8")
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elif mechanism == "EXTERNAL":
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if event["message"] != "+":
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event["server"].send_authenticate("*")
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else:
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auth_text = "+"
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elif mechanism.startswith("SCRAM-"):
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if event["message"] == "+":
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# start SCRAM handshake
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# create SCRAM helper
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sasl_username, sasl_password = sasl["args"].split(":", 1)
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algo = mechanism.split("SCRAM-", 1)[1]
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event["server"]._scram = scram.SCRAM(
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algo, sasl_username, sasl_password)
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# generate client-first-message
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auth_text = event["server"]._scram.client_first()
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else:
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current_scram = event["server"]._scram
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data = base64.b64decode(event["message"])
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if current_scram.state == scram.SCRAMState.ClientFirst:
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# use server-first-message to generate client-final-message
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auth_text = current_scram.server_first(data)
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elif current_scram.state == scram.SCRAMState.ClientFinal:
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# use server-final-message to check server proof
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verified = current_scram.server_final(data)
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del event["server"]._scram
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if verified:
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auth_text = "+"
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else:
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if current_scram.state == scram.SCRAMState.VerifyFailed:
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# server gave a bad verification so we should panic
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event["server"].disconnect()
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raise ValueError("Server SCRAM verification failed")
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else:
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raise ValueError("unknown sasl mechanism '%s'" % mechanism)
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if not auth_text == None:
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if not auth_text == "+":
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auth_text = base64.b64encode(auth_text)
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auth_text = auth_text.decode("utf8")
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event["server"].send_authenticate(auth_text)
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def _end_sasl(self, server):
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server.capability_done("sasl")
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@utils.hook("received.numeric.903")
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def sasl_success(self, event):
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self._end_sasl(event["server"])
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@utils.hook("received.numeric.904")
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def sasl_failure(self, event):
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self.log.warn("SASL failure for %s: %s",
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[str(event["server"]), event["args"][1]])
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self._end_sasl(event["server"])
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