Merge remote-tracking branch 'tor-gitlab/mr/195' into maint-0.3.5

  o Minor bugfixes (testing, portability):

    - Fix our Python reference-implementation for the v3 onion service

      handshake so that it works correctly with the version of hashlib provided

      by Python 3.9. Fixes part of bug 40179; bugfix on 0.3.1.6-rc.

try:

    # Pull the sha3 functions in.

    from hashlib import sha3_256, shake_256

    shake_squeeze = shake_256.digest

    def shake_squeeze(obj, n):

        return obj.digest(n)

except ImportError:

    if hasattr(sha3, "SHA3256"):

        # If this happens, then we have the old "sha3" module which

        # hashlib and pysha3 superseded.

        sha3_256 = sha3.SHA3256

        shake_256 = sha3.SHAKE256

        shake_squeeze = shake_256.squeeze

        def shake_squeeze(obj, n):

            return obj.squeeze(n)

    else:

        # error code 77 tells automake to skip this test

        sys.exit(77)