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, 98 insertions, 0 deletions

diff --git a/tests/_loop.py b/tests/_loop.py
new file mode 100644
index 00000000..a3740013
--- /dev/null
+++ b/tests/_loop.py
@@ -0,0 +1,98 @@
+# Copyright (C) 2003-2009  Robey Pointer <robeypointer@gmail.com>
+#
+# This file is part of paramiko.
+#
+# Paramiko is free software; you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation; either version 2.1 of the License, or (at your option)
+# any later version.
+#
+# Paramiko is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with Paramiko; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA.
+
+import socket
+import threading
+
+from paramiko.util import asbytes
+
+
+class LoopSocket:
+    """
+    A LoopSocket looks like a normal socket, but all data written to it is
+    delivered on the read-end of another LoopSocket, and vice versa.  It's
+    like a software "socketpair".
+    """
+
+    def __init__(self):
+        self.__in_buffer = bytes()
+        self.__lock = threading.Lock()
+        self.__cv = threading.Condition(self.__lock)
+        self.__timeout = None
+        self.__mate = None
+        self._closed = False
+
+    def close(self):
+        self.__unlink()
+        self._closed = True
+        try:
+            self.__lock.acquire()
+            self.__in_buffer = bytes()
+        finally:
+            self.__lock.release()
+
+    def send(self, data):
+        data = asbytes(data)
+        if self.__mate is None:
+            # EOF
+            raise EOFError()
+        self.__mate.__feed(data)
+        return len(data)
+
+    def recv(self, n):
+        self.__lock.acquire()
+        try:
+            if self.__mate is None:
+                # EOF
+                return bytes()
+            if len(self.__in_buffer) == 0:
+                self.__cv.wait(self.__timeout)
+            if len(self.__in_buffer) == 0:
+                raise socket.timeout
+            out = self.__in_buffer[:n]
+            self.__in_buffer = self.__in_buffer[n:]
+            return out
+        finally:
+            self.__lock.release()
+
+    def settimeout(self, n):
+        self.__timeout = n
+
+    def link(self, other):
+        self.__mate = other
+        self.__mate.__mate = self
+
+    def __feed(self, data):
+        self.__lock.acquire()
+        try:
+            self.__in_buffer += data
+            self.__cv.notify_all()
+        finally:
+            self.__lock.release()
+
+    def __unlink(self):
+        m = None
+        self.__lock.acquire()
+        try:
+            if self.__mate is not None:
+                m = self.__mate
+                self.__mate = None
+        finally:
+            self.__lock.release()
+        if m is not None:
+            m.__unlink()