Migrate rest of main keys and update suite to be more pytest-relaxed compat

Main branch as of today:

350 passed, 21 skipped, 52 deselected, 3 warnings in 11.10s

This branch as of this commit:

361 passed, 21 skipped, 52 deselected, 3 warnings in 10.51s

Of those 11 "new" tests, 8 are ones I wrote (tests/pkey.py). Hard to
figure out what the other 3 are given pytest-relaxed's output is very
different from regular verbose pytest. oops.

1 files changed, 0 insertions, 178 deletions

diff --git a/tests/util.py b/tests/util.py
deleted file mode 100644
index 2f1c5ac2..00000000
--- a/tests/util.py
+++ /dev/null
@@ -1,178 +0,0 @@
-from os.path import dirname, realpath, join
-import builtins
-import os
-from pathlib import Path
-import struct
-import sys
-import unittest
-
-import pytest
-
-from paramiko.ssh_gss import GSS_AUTH_AVAILABLE
-
-from cryptography.exceptions import UnsupportedAlgorithm, _Reasons
-from cryptography.hazmat.backends import default_backend
-from cryptography.hazmat.primitives import hashes
-from cryptography.hazmat.primitives.asymmetric import padding, rsa
-
-tests_dir = dirname(realpath(__file__))
-
-
-def _support(filename):
-    base = Path(tests_dir)
-    top = base / filename
-    deeper = base / "_support" / filename
-    return str(deeper if deeper.exists() else top)
-
-
-def _config(name):
-    return join(tests_dir, "configs", name)
-
-
-needs_gssapi = pytest.mark.skipif(
-    not GSS_AUTH_AVAILABLE, reason="No GSSAPI to test"
-)
-
-
-def needs_builtin(name):
-    """
-    Skip decorated test if builtin name does not exist.
-    """
-    reason = "Test requires a builtin '{}'".format(name)
-    return pytest.mark.skipif(not hasattr(builtins, name), reason=reason)
-
-
-slow = pytest.mark.slow
-
-# GSSAPI / Kerberos related tests need a working Kerberos environment.
-# The class `KerberosTestCase` provides such an environment or skips all tests.
-# There are 3 distinct cases:
-#
-# - A Kerberos environment has already been created and the environment
-#   contains the required information.
-#
-# - We can use the package 'k5test' to setup an working kerberos environment on
-#   the fly.
-#
-# - We skip all tests.
-#
-# ToDo: add a Windows specific implementation?
-
-if (
-    os.environ.get("K5TEST_USER_PRINC", None)
-    and os.environ.get("K5TEST_HOSTNAME", None)
-    and os.environ.get("KRB5_KTNAME", None)
-):  # add other vars as needed
-
-    # The environment provides the required information
-    class DummyK5Realm:
-        def __init__(self):
-            for k in os.environ:
-                if not k.startswith("K5TEST_"):
-                    continue
-                setattr(self, k[7:].lower(), os.environ[k])
-            self.env = {}
-
-    class KerberosTestCase(unittest.TestCase):
-        @classmethod
-        def setUpClass(cls):
-            cls.realm = DummyK5Realm()
-
-        @classmethod
-        def tearDownClass(cls):
-            del cls.realm
-
-else:
-    try:
-        # Try to setup a kerberos environment
-        from k5test import KerberosTestCase
-    except Exception:
-        # Use a dummy, that skips all tests
-        class KerberosTestCase(unittest.TestCase):
-            @classmethod
-            def setUpClass(cls):
-                raise unittest.SkipTest(
-                    "Missing extension package k5test. "
-                    'Please run "pip install k5test" '
-                    "to install it."
-                )
-
-
-def update_env(testcase, mapping, env=os.environ):
-    """Modify os.environ during a test case and restore during cleanup."""
-    saved_env = env.copy()
-
-    def replace(target, source):
-        target.update(source)
-        for k in list(target):
-            if k not in source:
-                target.pop(k, None)
-
-    testcase.addCleanup(replace, env, saved_env)
-    env.update(mapping)
-    return testcase
-
-
-def k5shell(args=None):
-    """Create a shell with an kerberos environment
-
-    This can be used to debug paramiko or to test the old GSSAPI.
-    To test a different GSSAPI, simply activate a suitable venv
-    within the shell.
-    """
-    import k5test
-    import atexit
-    import subprocess
-
-    k5 = k5test.K5Realm()
-    atexit.register(k5.stop)
-    os.environ.update(k5.env)
-    for n in ("realm", "user_princ", "hostname"):
-        os.environ["K5TEST_" + n.upper()] = getattr(k5, n)
-
-    if not args:
-        args = sys.argv[1:]
-    if not args:
-        args = [os.environ.get("SHELL", "bash")]
-    sys.exit(subprocess.call(args))
-
-
-def is_low_entropy():
-    """
-    Attempts to detect whether running interpreter is low-entropy.
-
-    "low-entropy" is defined as being in 32-bit mode and with the hash seed set
-    to zero.
-    """
-    is_32bit = struct.calcsize("P") == 32 / 8
-    # I don't see a way to tell internally if the hash seed was set this
-    # way, but env should be plenty sufficient, this is only for testing.
-    return is_32bit and os.environ.get("PYTHONHASHSEED", None) == "0"
-
-
-def sha1_signing_unsupported():
-    """
-    This is used to skip tests in environments where SHA-1 signing is
-    not supported by the backend.
-    """
-    private_key = rsa.generate_private_key(
-        public_exponent=65537, key_size=2048, backend=default_backend()
-    )
-    message = b"Some dummy text"
-    try:
-        private_key.sign(
-            message,
-            padding.PSS(
-                mgf=padding.MGF1(hashes.SHA1()),
-                salt_length=padding.PSS.MAX_LENGTH,
-            ),
-            hashes.SHA1(),
-        )
-        return False
-    except UnsupportedAlgorithm as e:
-        return e._reason is _Reasons.UNSUPPORTED_HASH
-
-
-requires_sha1_signing = unittest.skipIf(
-    sha1_signing_unsupported(), "SHA-1 signing not supported"
-)