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TLSListener: exception during handshake

See original GitHub issue

Run the TLSListener example, but comment out the line that calls load_verify_locations. Because the certificate is self-signed, the client will throw ssl.SSLCertVerificationError. However, the server also throws an exception:

Traceback (most recent call last):
  File "/home/yannik/.local/lib/python3.8/site-packages/anyio/streams/tls.py", line 98, in _call_sslobject_method
    result = func(*args)
  File "/usr/lib/python3.8/ssl.py", line 944, in do_handshake
    self._sslobj.do_handshake()
ssl.SSLSyscallError: Some I/O error occurred (_ssl.c:1108)

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "server.py", line 25, in <module>
    run(main)
  File "/home/yannik/.local/lib/python3.8/site-packages/anyio/_core/_eventloop.py", line 52, in run
    return asynclib.run(func, *args, **backend_options)  # type: ignore
  File "/home/yannik/.local/lib/python3.8/site-packages/anyio/_backends/_asyncio.py", line 160, in run
    return native_run(wrapper(), debug=debug)
  File "/usr/lib/python3.8/asyncio/runners.py", line 43, in run
    return loop.run_until_complete(main)
  File "/usr/lib/python3.8/asyncio/base_events.py", line 608, in run_until_complete
    return future.result()
  File "/home/yannik/.local/lib/python3.8/site-packages/anyio/_backends/_asyncio.py", line 155, in wrapper
    return await func(*args)
  File "server.py", line 23, in main
    await listener.serve(handle)
  File "/home/yannik/.local/lib/python3.8/site-packages/anyio/streams/tls.py", line 208, in serve
    await self.listener.serve(handler_wrapper, task_group)
  File "/home/yannik/.local/lib/python3.8/site-packages/anyio/streams/stapled.py", line 113, in serve
    await tg.spawn(listener.serve, handler, task_group)
  File "/home/yannik/.local/lib/python3.8/site-packages/anyio/_backends/_asyncio.py", line 438, in __aexit__
    raise exceptions[0]
  File "/home/yannik/.local/lib/python3.8/site-packages/anyio/_backends/_asyncio.py", line 466, in _run_wrapped_task
    await func(*args)
  File "/home/yannik/.local/lib/python3.8/site-packages/anyio/abc/sockets.py", line 109, in serve
    await task_group.spawn(handler, stream)
  File "/home/yannik/.local/lib/python3.8/site-packages/anyio/_backends/_asyncio.py", line 438, in __aexit__
    raise exceptions[0]
  File "/home/yannik/.local/lib/python3.8/site-packages/anyio/_backends/_asyncio.py", line 466, in _run_wrapped_task
    await func(*args)
  File "/home/yannik/.local/lib/python3.8/site-packages/anyio/streams/tls.py", line 204, in handler_wrapper
    wrapped_stream = await TLSStream.wrap(stream, ssl_context=self.ssl_context,
  File "/home/yannik/.local/lib/python3.8/site-packages/anyio/streams/tls.py", line 92, in wrap
    await wrapper._call_sslobject_method(ssl_object.do_handshake)
  File "/home/yannik/.local/lib/python3.8/site-packages/anyio/streams/tls.py", line 117, in _call_sslobject_method
    raise BrokenResourceError from exc
anyio.BrokenResourceError

There seems to be no way to catch this exception before it crashes the server. I can put a try-except around await listener.serve(handle) and restart the server after the exception occurs, but at this point all clients have been disconnected already.

Issue Analytics

State:
Created 3 years ago
Comments:6 (4 by maintainers)

Top GitHub Comments

1reaction

kinnaycommented, Jan 31, 2021

Yes, sorry, looks good to me.

0reactions

agronholmcommented, Jan 30, 2021

@kinnay you haven’t commented yet. Have you looked at the PR?

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