don't try SASL twice, try SASL on CAP NEW

ircrobots/sasl.py

@@ -15,6 +15,7 @@ SASL_USERPASS_MECHANISMS = [
 ]
 
 class SASLResult(Enum):
+    NONE    = 0
     SUCCESS = 1
     FAILURE = 2
     ALREADY = 3

ircrobots/server.py

@@ -9,7 +9,7 @@ from irctokens        import build, Line, tokenise
 from .ircv3     import Capability, CAPS, CAP_SASL
 from .interface import ConnectionParams, IServer, PriorityLine, SendPriority
 from .matching  import BaseResponse
-from .sasl      import SASLContext
+from .sasl      import SASLContext, SASLResult
 
 sc = ssl.create_default_context(ssl.Purpose.SERVER_AUTH)
 
@@ -26,6 +26,7 @@ class Server(IServer):
 
         self.throttle = Throttler(
             rate_limit=THROTTLE_RATE, period=THROTTLE_TIME)
+        self.sasl_state = SASLResult.NONE
 
         self._write_queue: PriorityQueue[PriorityLine] = PriorityQueue()
 
@@ -66,6 +67,8 @@ class Server(IServer):
                 await self._cap_ls_done()
             elif emit.subcommand in ["ACK", "NAK"]:
                 await self._cap_ack(emit)
+            elif emit.subcommand == "NEW":
+                await self._cap_new()
 
     async def _on_read_line(self, line: Line):
         for i, (response, future) in enumerate(self._wait_for):
@@ -124,13 +127,27 @@ class Server(IServer):
         if matches:
             self._requested_caps = matches
             await self.send(build("CAP", ["REQ", " ".join(matches)]))
+
     async def _cap_ack(self, emit: Emit):
-        if not self.params.sasl is None and self.cap_agreed(CAP_SASL):
-            await SASLContext(self).from_params(self.params.sasl)
+        await self._maybe_sasl()
 
         for cap in (emit.tokens or []):
             if cap in self._requested_caps:
                 self._requested_caps.remove(cap)
         if not self._requested_caps:
             await self.send(build("CAP", ["END"]))
+
+    async def _cap_new(self):
+        await self._maybe_sasl()
+
+    async def _maybe_sasl(self) -> bool:
+        if (self.sasl_state == SASLResult.NONE and
+                not self.params.sasl is None and
+                self.cap_agreed(CAP_SASL)):
+            res = await SASLContext(self).from_params(self.params.sasl)
+            self.sasl_state = res
+            return True
+        else:
+            return False
+
     # /CAP-related