Merge branch 'master' into 1013-int

23 files changed, 446 insertions, 55 deletions

diff --git a/paramiko/__init__.py b/paramiko/__init__.py
index d67ad62f..5d3a10fc 100644
--- a/paramiko/__init__.py
+++ b/paramiko/__init__.py
@@ -30,7 +30,7 @@ __license__ = "GNU Lesser General Public License (LGPL)"
 
 from paramiko.transport import SecurityOptions, Transport
 from paramiko.client import (
-    SSHClient, MissingHostKeyPolicy, AutoAddPolicy, RejectPolicy, 
+    SSHClient, MissingHostKeyPolicy, AutoAddPolicy, RejectPolicy,
     WarningPolicy,
 )
 from paramiko.auth_handler import AuthHandler
@@ -57,7 +57,7 @@ from paramiko.message import Message
 from paramiko.packet import Packetizer
 from paramiko.file import BufferedFile
 from paramiko.agent import Agent, AgentKey
-from paramiko.pkey import PKey
+from paramiko.pkey import PKey, PublicBlob
 from paramiko.hostkeys import HostKeys
 from paramiko.config import SSHConfig
 from paramiko.proxy import ProxyCommand
diff --git a/paramiko/agent.py b/paramiko/agent.py
index bc857efa..7a4dde21 100644
--- a/paramiko/agent.py
+++ b/paramiko/agent.py
@@ -387,6 +387,7 @@ class AgentKey(PKey):
     def __init__(self, agent, blob):
         self.agent = agent
         self.blob = blob
+        self.public_blob = None
         self.name = Message(blob).get_text()
 
     def asbytes(self):
diff --git a/paramiko/auth_handler.py b/paramiko/auth_handler.py
index e229df8d..6b66e0e0 100644
--- a/paramiko/auth_handler.py
+++ b/paramiko/auth_handler.py
@@ -187,8 +187,13 @@ class AuthHandler (object):
         m.add_string(service)
         m.add_string('publickey')
         m.add_boolean(True)
-        m.add_string(key.get_name())
-        m.add_string(key)
+        # Use certificate contents, if available, plain pubkey otherwise
+        if key.public_blob:
+            m.add_string(key.public_blob.key_type)
+            m.add_string(key.public_blob.key_blob)
+        else:
+            m.add_string(key.get_name())
+            m.add_string(key)
         return m.asbytes()
 
     def wait_for_response(self, event):
@@ -252,8 +257,14 @@ class AuthHandler (object):
                 m.add_string(password)
             elif self.auth_method == 'publickey':
                 m.add_boolean(True)
-                m.add_string(self.private_key.get_name())
-                m.add_string(self.private_key)
+                # Use certificate contents, if available, plain pubkey
+                # otherwise
+                if self.private_key.public_blob:
+                    m.add_string(self.private_key.public_blob.key_type)
+                    m.add_string(self.private_key.public_blob.key_blob)
+                else:
+                    m.add_string(self.private_key.get_name())
+                    m.add_string(self.private_key)
                 blob = self._get_session_blob(
                     self.private_key, 'ssh-connection', self.username)
                 sig = self.private_key.sign_ssh_data(blob)
@@ -456,10 +467,9 @@ class AuthHandler (object):
                     INFO,
                     'Auth rejected: public key: %s' % str(e))
                 key = None
-            except:
-                self.transport._log(
-                    INFO,
-                    'Auth rejected: unsupported or mangled public key')
+            except Exception as e:
+                msg = 'Auth rejected: unsupported or mangled public key ({0}: {1})' # noqa
+                self.transport._log(INFO, msg.format(e.__class__.__name__, e))
                 key = None
             if key is None:
                 self._disconnect_no_more_auth()
diff --git a/paramiko/client.py b/paramiko/client.py
index 936693fc..bff223ea 100644
--- a/paramiko/client.py
+++ b/paramiko/client.py
@@ -240,9 +240,23 @@ class SSHClient (ClosingContextManager):
         Authentication is attempted in the following order of priority:
 
             - The ``pkey`` or ``key_filename`` passed in (if any)
+
+              - ``key_filename`` may contain OpenSSH public certificate paths
+                as well as regular private-key paths; when files ending in
+                ``-cert.pub`` are found, they are assumed to match a private
+                key, and both components will be loaded. (The private key
+                itself does *not* need to be listed in ``key_filename`` for
+                this to occur - *just* the certificate.)
+
             - Any key we can find through an SSH agent
             - Any "id_rsa", "id_dsa" or "id_ecdsa" key discoverable in
               ``~/.ssh/``
+
+              - When OpenSSH-style public certificates exist that match an
+                existing such private key (so e.g. one has ``id_rsa`` and
+                ``id_rsa-cert.pub``) the certificate will be loaded alongside
+                the private key and used for authentication.
+
             - Plain username/password auth, if a password was given
 
         If a private key requires a password to unlock it, and a password is
@@ -257,8 +271,8 @@ class SSHClient (ClosingContextManager):
             a password to use for authentication or for unlocking a private key
         :param .PKey pkey: an optional private key to use for authentication
         :param str key_filename:
-            the filename, or list of filenames, of optional private key(s) to
-            try for authentication
+            the filename, or list of filenames, of optional private key(s)
+            and/or certs to try for authentication
         :param float timeout:
             an optional timeout (in seconds) for the TCP connect
         :param bool allow_agent:
@@ -499,12 +513,44 @@ class SSHClient (ClosingContextManager):
         """
         return self._transport
 
+    def _key_from_filepath(self, filename, klass, password):
+        """
+        Attempt to derive a `.PKey` from given string path ``filename``:
+
+        - If ``filename`` appears to be a cert, the matching private key is
+          loaded.
+        - Otherwise, the filename is assumed to be a private key, and the
+          matching public cert will be loaded if it exists.
+        """
+        cert_suffix = '-cert.pub'
+        # Assume privkey, not cert, by default
+        if filename.endswith(cert_suffix):
+            key_path = filename[:-len(cert_suffix)]
+            cert_path = filename
+        else:
+            key_path = filename
+            cert_path = filename + cert_suffix
+        # Blindly try the key path; if no private key, nothing will work.
+        key = klass.from_private_key_file(key_path, password)
+        # TODO: change this to 'Loading' instead of 'Trying' sometime; probably
+        # when #387 is released, since this is a critical log message users are
+        # likely testing/filtering for (bah.)
+        msg = "Trying discovered key {0} in {1}".format(
+            hexlify(key.get_fingerprint()), key_path,
+        )
+        self._log(DEBUG, msg)
+        # Attempt to load cert if it exists.
+        if os.path.isfile(cert_path):
+            key.load_certificate(cert_path)
+            self._log(DEBUG, "Adding public certificate {0}".format(cert_path))
+        return key
+
     def _auth(self, username, password, pkey, key_filenames, allow_agent,
               look_for_keys, gss_auth, gss_kex, gss_deleg_creds, gss_host):
         """
         Try, in order:
 
-            - The key passed in, if one was passed in.
+            - The key(s) passed in, if one was passed in.
             - Any key we can find through an SSH agent (if allowed).
             - Any "id_rsa", "id_dsa" or "id_ecdsa" key discoverable in ~/.ssh/
               (if allowed).
@@ -556,12 +602,9 @@ class SSHClient (ClosingContextManager):
             for key_filename in key_filenames:
                 for pkey_class in (RSAKey, DSSKey, ECDSAKey, Ed25519Key):
                     try:
-                        key = pkey_class.from_private_key_file(
-                            key_filename, password)
-                        self._log(
-                            DEBUG,
-                            'Trying key %s from %s' % (
-                                hexlify(key.get_fingerprint()), key_filename))
+                        key = self._key_from_filepath(
+                            key_filename, pkey_class, password,
+                        )
                         allowed_types = set(
                             self._transport.auth_publickey(username, key))
                         two_factor = (allowed_types & two_factor_types)
@@ -607,19 +650,19 @@ class SSHClient (ClosingContextManager):
                         "~/%s/id_%s" % (directory, name)
                     )
                     if os.path.isfile(full_path):
+                        # TODO: only do this append if below did not run
                         keyfiles.append((keytype, full_path))
+                        if os.path.isfile(full_path + '-cert.pub'):
+                            keyfiles.append((keytype, full_path + '-cert.pub'))
 
             if not look_for_keys:
                 keyfiles = []
 
             for pkey_class, filename in keyfiles:
                 try:
-                    key = pkey_class.from_private_key_file(filename, password)
-                    self._log(
-                        DEBUG,
-                        'Trying discovered key %s in %s' % (
-                            hexlify(key.get_fingerprint()), filename))
-
+                    key = self._key_from_filepath(
+                        filename, pkey_class, password,
+                    )
                     # for 2-factor auth a successfully auth'd key will result
                     # in ['password']
                     allowed_types = set(
diff --git a/paramiko/compress.py b/paramiko/compress.py
index b55f0b1d..5073109c 100644
--- a/paramiko/compress.py
+++ b/paramiko/compress.py
@@ -25,7 +25,8 @@ import zlib
 
 class ZlibCompressor (object):
     def __init__(self):
-        self.z = zlib.compressobj(9)
+        # Use the default level of zlib compression
+        self.z = zlib.compressobj()
 
     def __call__(self, data):
         return self.z.compress(data) + self.z.flush(zlib.Z_FULL_FLUSH)
diff --git a/paramiko/dsskey.py b/paramiko/dsskey.py
index 9af5d0c1..f9c02153 100644
--- a/paramiko/dsskey.py
+++ b/paramiko/dsskey.py
@@ -49,6 +49,7 @@ class DSSKey(PKey):
         self.g = None
         self.y = None
         self.x = None
+        self.public_blob = None
         if file_obj is not None:
             self._from_private_key(file_obj, password)
             return
@@ -60,10 +61,11 @@ class DSSKey(PKey):
         if vals is not None:
             self.p, self.q, self.g, self.y = vals
         else:
-            if msg is None:
-                raise SSHException('Key object may not be empty')
-            if msg.get_text() != 'ssh-dss':
-                raise SSHException('Invalid key')
+            self._check_type_and_load_cert(
+                msg=msg,
+                key_type='ssh-dss',
+                cert_type='ssh-dss-cert-v01@openssh.com',
+            )
             self.p = msg.get_mpint()
             self.q = msg.get_mpint()
             self.g = msg.get_mpint()
diff --git a/paramiko/ecdsakey.py b/paramiko/ecdsakey.py
index fa850c2e..5a0164d8 100644
--- a/paramiko/ecdsakey.py
+++ b/paramiko/ecdsakey.py
@@ -105,6 +105,7 @@ class ECDSAKey(PKey):
                  vals=None, file_obj=None, validate_point=True):
         self.verifying_key = None
         self.signing_key = None
+        self.public_blob = None
         if file_obj is not None:
             self._from_private_key(file_obj, password)
             return
@@ -118,12 +119,29 @@ class ECDSAKey(PKey):
             c_class = self.signing_key.curve.__class__
             self.ecdsa_curve = self._ECDSA_CURVES.get_by_curve_class(c_class)
         else:
-            if msg is None:
-                raise SSHException('Key object may not be empty')
+            # Must set ecdsa_curve first; subroutines called herein may need to
+            # spit out our get_name(), which relies on this.
+            key_type = msg.get_text()
+            # But this also means we need to hand it a real key/curve
+            # identifier, so strip out any cert business. (NOTE: could push
+            # that into _ECDSACurveSet.get_by_key_format_identifier(), but it
+            # feels more correct to do it here?)
+            suffix = '-cert-v01@openssh.com'
+            if key_type.endswith(suffix):
+                key_type = key_type[:-len(suffix)]
             self.ecdsa_curve = self._ECDSA_CURVES.get_by_key_format_identifier(
-                msg.get_text())
-            if self.ecdsa_curve is None:
-                raise SSHException('Invalid key')
+                key_type
+            )
+            key_types = self._ECDSA_CURVES.get_key_format_identifier_list()
+            cert_types = [
+                '{0}-cert-v01@openssh.com'.format(x)
+                for x in key_types
+            ]
+            self._check_type_and_load_cert(
+                msg=msg,
+                key_type=key_types,
+                cert_type=cert_types,
+            )
             curvename = msg.get_text()
             if curvename != self.ecdsa_curve.nist_name:
                 raise SSHException("Can't handle curve of type %s" % curvename)
diff --git a/paramiko/ed25519key.py b/paramiko/ed25519key.py
index a50d68bc..2e1eb18a 100644
--- a/paramiko/ed25519key.py
+++ b/paramiko/ed25519key.py
@@ -50,8 +50,11 @@ class Ed25519Key(PKey):
         if msg is None and data is not None:
             msg = Message(data)
         if msg is not None:
-            if msg.get_text() != "ssh-ed25519":
-                raise SSHException("Invalid key")
+            self._check_type_and_load_cert(
+                msg=msg,
+                key_type="ssh-ed25519",
+                cert_type="ssh-ed25519-cert-v01@openssh.com",
+            )
             verifying_key = nacl.signing.VerifyKey(msg.get_binary())
         elif filename is not None:
             with open(filename, "r") as f:
diff --git a/paramiko/pkey.py b/paramiko/pkey.py
index 35a26fc7..67723be2 100644
--- a/paramiko/pkey.py
+++ b/paramiko/pkey.py
@@ -31,8 +31,9 @@ from cryptography.hazmat.primitives.ciphers import algorithms, modes, Cipher
 
 from paramiko import util
 from paramiko.common import o600
-from paramiko.py3compat import u, encodebytes, decodebytes, b
+from paramiko.py3compat import u, encodebytes, decodebytes, b, string_types
 from paramiko.ssh_exception import SSHException, PasswordRequiredException
+from paramiko.message import Message
 
 
 class PKey(object):
@@ -363,3 +364,170 @@ class PKey(object):
             format,
             encryption
         ).decode())
+
+    def _check_type_and_load_cert(self, msg, key_type, cert_type):
+        """
+        Perform message type-checking & optional certificate loading.
+
+        This includes fast-forwarding cert ``msg`` objects past the nonce, so
+        that the subsequent fields are the key numbers; thus the caller may
+        expect to treat the message as key material afterwards either way.
+
+        The obtained key type is returned for classes which need to know what
+        it was (e.g. ECDSA.)
+        """
+        # Normalization; most classes have a single key type and give a string,
+        # but eg ECDSA is a 1:N mapping.
+        key_types = key_type
+        cert_types = cert_type
+        if isinstance(key_type, string_types):
+            key_types = [key_types]
+        if isinstance(cert_types, string_types):
+            cert_types = [cert_types]
+        # Can't do much with no message, that should've been handled elsewhere
+        if msg is None:
+            raise SSHException('Key object may not be empty')
+        # First field is always key type, in either kind of object. (make sure
+        # we rewind before grabbing it - sometimes caller had to do their own
+        # introspection first!)
+        msg.rewind()
+        type_ = msg.get_text()
+        # Regular public key - nothing special to do besides the implicit
+        # type check.
+        if type_ in key_types:
+            pass
+        # OpenSSH-compatible certificate - store full copy as .public_blob
+        # (so signing works correctly) and then fast-forward past the
+        # nonce.
+        elif type_ in cert_types:
+            # This seems the cleanest way to 'clone' an already-being-read
+            # message; they're *IO objects at heart and their .getvalue()
+            # always returns the full value regardless of pointer position.
+            self.load_certificate(Message(msg.asbytes()))
+            # Read out nonce as it comes before the public numbers.
+            # TODO: usefully interpret it & other non-public-number fields
+            # (requires going back into per-type subclasses.)
+            msg.get_string()
+        else:
+            err = 'Invalid key (class: {0}, data type: {1}'
+            raise SSHException(err.format(self.__class__.__name__, type_))
+
+    def load_certificate(self, value):
+        """
+        Supplement the private key contents with data loaded from an OpenSSH
+        public key (``.pub``) or certificate (``-cert.pub``) file, a string
+        containing such a file, or a `.Message` object.
+
+        The .pub contents adds no real value, since the private key
+        file includes sufficient information to derive the public
+        key info. For certificates, however, this can be used on
+        the client side to offer authentication requests to the server
+        based on certificate instead of raw public key.
+
+        See:
+        https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.certkeys
+
+        Note: very little effort is made to validate the certificate contents,
+        that is for the server to decide if it is good enough to authenticate
+        successfully.
+        """
+        if isinstance(value, Message):
+            constructor = 'from_message'
+        elif os.path.isfile(value):
+            constructor = 'from_file'
+        else:
+            constructor = 'from_string'
+        blob = getattr(PublicBlob, constructor)(value)
+        if not blob.key_type.startswith(self.get_name()):
+            err = "PublicBlob type {0} incompatible with key type {1}"
+            raise ValueError(err.format(blob.key_type, self.get_name()))
+        self.public_blob = blob
+
+
+# General construct for an OpenSSH style Public Key blob
+# readable from a one-line file of the format:
+#     <key-name> <base64-blob> [<comment>]
+# Of little value in the case of standard public keys
+# {ssh-rsa, ssh-dss, ssh-ecdsa, ssh-ed25519}, but should
+# provide rudimentary support for {*-cert.v01}
+class PublicBlob(object):
+    """
+    OpenSSH plain public key or OpenSSH signed public key (certificate).
+
+    Tries to be as dumb as possible and barely cares about specific
+    per-key-type data.
+
+    ..note::
+        Most of the time you'll want to call `from_file`, `from_string` or
+        `from_message` for useful instantiation, the main constructor is
+        basically "I should be using ``attrs`` for this."
+    """
+    def __init__(self, type_, blob, comment=None):
+        """
+        Create a new public blob of given type and contents.
+
+        :param str type_: Type indicator, eg ``ssh-rsa``.
+        :param blob: The blob bytes themselves.
+        :param str comment: A comment, if one was given (e.g. file-based.)
+        """
+        self.key_type = type_
+        self.key_blob = blob
+        self.comment = comment
+
+    @classmethod
+    def from_file(cls, filename):
+        """
+        Create a public blob from a ``-cert.pub``-style file on disk.
+        """
+        with open(filename) as f:
+            string = f.read()
+        return cls.from_string(string)
+
+    @classmethod
+    def from_string(cls, string):
+        """
+        Create a public blob from a ``-cert.pub``-style string.
+        """
+        fields = string.split(None, 2)
+        if len(fields) < 2:
+            msg = "Not enough fields for public blob: {0}"
+            raise ValueError(msg.format(fields))
+        key_type = fields[0]
+        key_blob = decodebytes(b(fields[1]))
+        try:
+            comment = fields[2].strip()
+        except IndexError:
+            comment = None
+        # Verify that the blob message first (string) field matches the
+        # key_type
+        m = Message(key_blob)
+        blob_type = m.get_text()
+        if blob_type != key_type:
+            msg = "Invalid PublicBlob contents: key type={0!r}, but blob type={1!r}" # noqa
+            raise ValueError(msg.format(key_type, blob_type))
+        # All good? All good.
+        return cls(type_=key_type, blob=key_blob, comment=comment)
+
+    @classmethod
+    def from_message(cls, message):
+        """
+        Create a public blob from a network `.Message`.
+
+        Specifically, a cert-bearing pubkey auth packet, because by definition
+        OpenSSH-style certificates 'are' their own network representation."
+        """
+        type_ = message.get_text()
+        return cls(type_=type_, blob=message.asbytes())
+
+    def __str__(self):
+        ret = '{0} public key/certificate'.format(self.key_type)
+        if self.comment:
+            ret += "- {0}".format(self.comment)
+        return ret
+
+    def __eq__(self, other):
+        # Just piggyback on Message/BytesIO, since both of these should be one.
+        return self and other and self.key_blob == other.key_blob
+
+    def __ne__(self, other):
+        return not self == other
diff --git a/paramiko/rsakey.py b/paramiko/rsakey.py
index b5107515..1646fa4f 100644
--- a/paramiko/rsakey.py
+++ b/paramiko/rsakey.py
@@ -40,6 +40,7 @@ class RSAKey(PKey):
     def __init__(self, msg=None, data=None, filename=None, password=None,
                  key=None, file_obj=None):
         self.key = None
+        self.public_blob = None
         if file_obj is not None:
             self._from_private_key(file_obj, password)
             return
@@ -51,10 +52,11 @@ class RSAKey(PKey):
         if key is not None:
             self.key = key
         else:
-            if msg is None:
-                raise SSHException('Key object may not be empty')
-            if msg.get_text() != 'ssh-rsa':
-                raise SSHException('Invalid key')
+            self._check_type_and_load_cert(
+                msg=msg,
+                key_type='ssh-rsa',
+                cert_type='ssh-rsa-cert-v01@openssh.com',
+            )
             self.key = rsa.RSAPublicNumbers(
                 e=msg.get_mpint(), n=msg.get_mpint()
             ).public_key(default_backend())
diff --git a/paramiko/sftp_client.py b/paramiko/sftp_client.py
index dee0e2b2..51c02365 100644
--- a/paramiko/sftp_client.py
+++ b/paramiko/sftp_client.py
@@ -366,6 +366,11 @@ class SFTPClient(BaseSFTP, ClosingContextManager):
         """
         Rename a file or folder from ``oldpath`` to ``newpath``.
 
+        .. note::
+            This method implements 'standard' SFTP ``RENAME`` behavior; those
+            seeking the OpenSSH "POSIX rename" extension behavior should use
+            `posix_rename`.
+
         :param str oldpath:
             existing name of the file or folder
         :param str newpath:
@@ -392,6 +397,8 @@ class SFTPClient(BaseSFTP, ClosingContextManager):
         :raises:
             ``IOError`` -- if ``newpath`` is a folder, posix-rename is not
             supported by the server or something else goes wrong
+
+        :versionadded: 2.2
         """
         oldpath = self._adjust_cwd(oldpath)
         newpath = self._adjust_cwd(newpath)
diff --git a/paramiko/sftp_si.py b/paramiko/sftp_si.py
index 40969309..b43b582c 100644
--- a/paramiko/sftp_si.py
+++ b/paramiko/sftp_si.py
@@ -194,6 +194,11 @@ class SFTPServerInterface (object):
             ``newpath`` already exists.  (The rename operation should be
             non-desctructive.)
 
+        .. note::
+            This method implements 'standard' SFTP ``RENAME`` behavior; those
+            seeking the OpenSSH "POSIX rename" extension behavior should use
+            `posix_rename`.
+
         :param str oldpath:
             the requested path (relative or absolute) of the existing file.
         :param str newpath: the requested new path of the file.
@@ -210,6 +215,8 @@ class SFTPServerInterface (object):
             the requested path (relative or absolute) of the existing file.
         :param str newpath: the requested new path of the file.
         :return: an SFTP error code `int` like ``SFTP_OK``.
+
+        :versionadded: 2.2
         """
         return SFTP_OP_UNSUPPORTED
 
diff --git a/paramiko/transport.py b/paramiko/transport.py
index bab23fa1..df068b3c 100644
--- a/paramiko/transport.py
+++ b/paramiko/transport.py
@@ -204,11 +204,17 @@ class Transport(threading.Thread, ClosingContextManager):
 
     _key_info = {
         'ssh-rsa': RSAKey,
+        'ssh-rsa-cert-v01@openssh.com': RSAKey,
         'ssh-dss': DSSKey,
+        'ssh-dss-cert-v01@openssh.com': DSSKey,
         'ecdsa-sha2-nistp256': ECDSAKey,
+        'ecdsa-sha2-nistp256-cert-v01@openssh.com': ECDSAKey,
         'ecdsa-sha2-nistp384': ECDSAKey,
+        'ecdsa-sha2-nistp384-cert-v01@openssh.com': ECDSAKey,
         'ecdsa-sha2-nistp521': ECDSAKey,
+        'ecdsa-sha2-nistp521-cert-v01@openssh.com': ECDSAKey,
         'ssh-ed25519': Ed25519Key,
+        'ssh-ed25519-cert-v01@openssh.com': Ed25519Key,
     }
 
     _kex_info = {
@@ -1825,8 +1831,6 @@ class Transport(threading.Thread, ClosingContextManager):
                         continue
                     elif ptype == MSG_DISCONNECT:
                         self._parse_disconnect(m)
-                        self.active = False
-                        self.packetizer.close()
                         break
                     elif ptype == MSG_DEBUG:
                         self._parse_debug(m)
@@ -1850,8 +1854,7 @@ class Transport(threading.Thread, ClosingContextManager):
                             self._log(DEBUG, 'Ignoring message for dead channel %d' % chanid) # noqa
                         else:
                             self._log(ERROR, 'Channel request for unknown channel %d' % chanid) # noqa
-                            self.active = False
-                            self.packetizer.close()
+                            break
                     elif (
                         self.auth_handler is not None and
                         ptype in self.auth_handler._handler_table
diff --git a/sites/www/changelog.rst b/sites/www/changelog.rst
index dea044bf..4198e927 100644
--- a/sites/www/changelog.rst
+++ b/sites/www/changelog.rst
@@ -2,6 +2,55 @@
 Changelog
 =========
 
+* :bug:`60 major` (via :issue:`1037`) Paramiko originally defaulted to zlib
+  compression level 9 (when one connects with ``compression=True``; it defaults
+  to off.) This has been found to be quite wasteful and tends to cause much
+  longer transfers in most cases, than is necessary.
+
+  OpenSSH defaults to compression level 6, which is a much more reasonable
+  setting (nearly identical compression characteristics but noticeably,
+  sometimes significantly, faster transmission); Paramiko now uses this value
+  instead.
+
+  Thanks to Damien Dubé for the report and ``@DrNeutron`` for investigating &
+  submitting the patch.
+* :support:`-` Display exception type and message when logging auth-rejection
+  messages (ones reading ``Auth rejected: unsupported or mangled public key``);
+  previously this error case had a bare except and did not display exactly why
+  the key failed. It will now append info such as ``KeyError:
+  'some-unknown-type-string'`` or similar.
+* :feature:`1042` (also partially :issue:`531`) Implement basic client-side
+  certificate authentication (as per the OpenSSH vendor extension.)
+
+  The core implementation is `PKey.load_certificate
+  <paramiko.pkey.PKey.load_certificate>` and its corresponding ``.public_blob``
+  attribute on key objects, which is honored in the auth and transport modules.
+  Additionally, `SSHClient.connect <paramiko.client.SSHClient.connect>` will
+  now automatically load certificate data alongside private key data when one
+  has appropriately-named cert files (e.g. ``id_rsa-cert.pub``) - see its
+  docstring for details.
+
+  Thanks to Jason Rigby for a first draft (:issue:`531`) and to Paul Kapp for
+  the second draft, upon which the current functionality has been based (with
+  modifications.)
+
+  .. note::
+    This support is client-focused; Paramiko-driven server code is capable of
+    handling cert-bearing pubkey auth packets, *but* it does not interpret any
+    cert-specific fields, so the end result is functionally identical to a
+    vanilla pubkey auth process (and thus requires e.g. prepopulated
+    authorized-keys data.) We expect full server-side cert support to follow
+    later.
+
+* :support:`1041` Modify logic around explicit disconnect
+  messages, and unknown-channel situations, so that they rely on centralized
+  shutdown code instead of running their own. This is at worst removing some
+  unnecessary code, and may help with some situations where Paramiko hangs at
+  the end of a session. Thanks to Paul Kapp for the patch.
+* :support:`1012` (via :issue:`1016`) Enhance documentation around the new
+  `SFTP.posix_rename <paramiko.sftp_client.SFTPClient.posix_rename>` method so
+  it's referenced in the 'standard' ``rename`` method for increased visibility.
+  Thanks to Marius Flage for the report.
 * :release:`2.2.1 <2017-06-13>`
 * :bug:`993` Ed25519 host keys were not comparable/hashable, causing an
   exception if such a key existed in a ``known_hosts`` file. Thanks to Oleh
diff --git a/tasks.py b/tasks.py
index 42c18bd0..a34fd3ce 100644
--- a/tasks.py
+++ b/tasks.py
@@ -4,6 +4,7 @@ from shutil import rmtree, copytree
 from invoke import Collection, task
 from invocations.docs import docs, www, sites
 from invocations.packaging.release import ns as release_coll, publish
+from invocations.testing import count_errors
 
 
 # Until we move to spec-based testing
@@ -49,7 +50,7 @@ def release(ctx, sdist=True, wheel=True, sign=True, dry_run=False):
 # aliasing, defaults etc.
 release_coll.tasks['publish'] = release
 
-ns = Collection(test, coverage, release_coll, docs, www, sites)
+ns = Collection(test, coverage, release_coll, docs, www, sites, count_errors)
 ns.configure({
     'packaging': {
         # NOTE: many of these are also set in kwarg defaults above; but having
diff --git a/tests/test_client.py b/tests/test_client.py
index e912d5b2..7ada13da 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -35,6 +35,7 @@ import time
 from tests.util import test_path
 
 import paramiko
+from paramiko.pkey import PublicBlob
 from paramiko.common import PY2
 from paramiko.ssh_exception import SSHException, AuthenticationException
 
@@ -47,10 +48,12 @@ FINGERPRINTS = {
 }
 
 
-class NullServer (paramiko.ServerInterface):
+class NullServer(paramiko.ServerInterface):
     def __init__(self, *args, **kwargs):
         # Allow tests to enable/disable specific key types
         self.__allowed_keys = kwargs.pop('allowed_keys', [])
+        # And allow them to set a (single...meh) expected public blob (cert)
+        self.__expected_public_blob = kwargs.pop('public_blob', None)
         super(NullServer, self).__init__(*args, **kwargs)
 
     def get_allowed_auths(self, username):
@@ -71,12 +74,18 @@ class NullServer (paramiko.ServerInterface):
             expected = FINGERPRINTS[key.get_name()]
         except KeyError:
             return paramiko.AUTH_FAILED
-        if (
+        # Base check: allowed auth type & fingerprint matches
+        happy = (
             key.get_name() in self.__allowed_keys and
             key.get_fingerprint() == expected
+        )
+        # Secondary check: if test wants assertions about cert data
+        if (
+            self.__expected_public_blob is not None and
+            key.public_blob != self.__expected_public_blob
         ):
-            return paramiko.AUTH_SUCCESSFUL
-        return paramiko.AUTH_FAILED
+            happy = False
+        return paramiko.AUTH_SUCCESSFUL if happy else paramiko.AUTH_FAILED
 
     def check_channel_request(self, kind, chanid):
         return paramiko.OPEN_SUCCEEDED
@@ -117,7 +126,7 @@ class SSHClientTest (unittest.TestCase):
             if hasattr(self, attr):
                 getattr(self, attr).close()
 
-    def _run(self, allowed_keys=None, delay=0):
+    def _run(self, allowed_keys=None, delay=0, public_blob=None):
         if allowed_keys is None:
             allowed_keys = FINGERPRINTS.keys()
         self.socks, addr = self.sockl.accept()
@@ -128,7 +137,7 @@ class SSHClientTest (unittest.TestCase):
         keypath = test_path('test_ecdsa_256.key')
         host_key = paramiko.ECDSAKey.from_private_key_file(keypath)
         self.ts.add_server_key(host_key)
-        server = NullServer(allowed_keys=allowed_keys)
+        server = NullServer(allowed_keys=allowed_keys, public_blob=public_blob)
         if delay:
             time.sleep(delay)
         self.ts.start_server(self.event, server)
@@ -140,7 +149,9 @@ class SSHClientTest (unittest.TestCase):
         The exception is ``allowed_keys`` which is stripped and handed to the
         ``NullServer`` used for testing.
         """
-        run_kwargs = {'allowed_keys': kwargs.pop('allowed_keys', None)}
+        run_kwargs = {}
+        for key in ('allowed_keys', 'public_blob'):
+            run_kwargs[key] = kwargs.pop(key, None)
         # Server setup
         threading.Thread(target=self._run, kwargs=run_kwargs).start()
         host_key = paramiko.RSAKey.from_private_key_file(test_path('test_rsa.key'))
@@ -248,6 +259,40 @@ class SSHClientTest (unittest.TestCase):
             allowed_keys=['ecdsa-sha2-nistp256'],
         )
 
+    def test_certs_allowed_as_key_filename_values(self):
+        # NOTE: giving cert path here, not key path. (Key path test is below.
+        # They're similar except for which path is given; the expected auth and
+        # server-side behavior is 100% identical.)
+        # NOTE: only bothered whipping up one cert per overall class/family.
+        for type_ in ('rsa', 'dss', 'ecdsa_256', 'ed25519'):
+            cert_path = test_path('test_{0}.key-cert.pub'.format(type_))
+            self._test_connection(
+                key_filename=cert_path,
+                public_blob=PublicBlob.from_file(cert_path),
+            )
+
+    def test_certs_implicitly_loaded_alongside_key_filename_keys(self):
+        # NOTE: a regular test_connection() w/ test_rsa.key would incidentally
+        # test this (because test_xxx.key-cert.pub exists) but incidental tests
+        # stink, so NullServer and friends were updated to allow assertions
+        # about the server-side key object's public blob. Thus, we can prove
+        # that a specific cert was found, along with regular authorization
+        # succeeding proving that the overall flow works.
+        for type_ in ('rsa', 'dss', 'ecdsa_256', 'ed25519'):
+            key_path = test_path('test_{0}.key'.format(type_))
+            self._test_connection(
+                key_filename=key_path,
+                public_blob=PublicBlob.from_file(
+                    '{0}-cert.pub'.format(key_path)
+                ),
+            )
+
+    def test_default_key_locations_trigger_cert_loads_if_found(self):
+        # TODO: what it says on the tin: ~/.ssh/id_rsa tries to load
+        # ~/.ssh/id_rsa-cert.pub. Right now no other tests actually test that
+        # code path (!) so we're punting too, sob.
+        pass
+
     def test_4_auto_add_policy(self):
         """
         verify that SSHClient's AutoAddPolicy works.
diff --git a/tests/test_dss.key-cert.pub b/tests/test_dss.key-cert.pub
new file mode 100644
index 00000000..07fd5578
--- /dev/null
+++ b/tests/test_dss.key-cert.pub
@@ -0,0 +1 @@
+ssh-dss-cert-v01@openssh.com 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 tests/test_dss.key.pub
diff --git a/tests/test_ecdsa_256.key-cert.pub b/tests/test_ecdsa_256.key-cert.pub
new file mode 100644
index 00000000..f2c93ccf
--- /dev/null
+++ b/tests/test_ecdsa_256.key-cert.pub
@@ -0,0 +1 @@
+ecdsa-sha2-nistp256-cert-v01@openssh.com AAAAKGVjZHNhLXNoYTItbmlzdHAyNTYtY2VydC12MDFAb3BlbnNzaC5jb20AAAAgJ+ZkRXedIWPl9y6fvel60p47ys5WgwMSjiwzJ2Ho+4MAAAAIbmlzdHAyNTYAAABBBJSPZm3ZWkvk/Zx8WP+fZRZ5/NBBHnGQwR6uIC6XHGPDIHuWUzIjAwA0bzqkOUffEsbLe+uQgKl5kbc/L8KA/eoAAAAAAAAAAAAAAAEAAAAJdXNlcl90ZXN0AAAACAAAAAR0ZXN0AAAAAAAAAAD//////////wAAAAAAAACCAAAAFXBlcm1pdC1YMTEtZm9yd2FyZGluZwAAAAAAAAAXcGVybWl0LWFnZW50LWZvcndhcmRpbmcAAAAAAAAAFnBlcm1pdC1wb3J0LWZvcndhcmRpbmcAAAAAAAAACnBlcm1pdC1wdHkAAAAAAAAADnBlcm1pdC11c2VyLXJjAAAAAAAAAAAAAAEXAAAAB3NzaC1yc2EAAAADAQABAAABAQDskr46Umjxh3wo7PoPQsSVS3xt6+5PhwmXrnVtBBnkOo+zHRwQo8G8sY+Lc6oOOzA5GCSawKOwqE305GIDfB8/L9EKOkAjdN18imDjw/YuJFA4bl9yFhsXrCb1GZPJw0pJ0H0Eid9EldyMQAhGE49MWvnFMQl1TgO6YWq/g71xAFimge0LvVWijlbMy7O+nsGxSpinIprV5S9Viv8XC/ku89tadZfca1uxq751aGfAWGeYrVytpUl8UO0ggqH6BaUvkDU7rWh2n5RHUTvgzceKWnz5wqd8BngK37WmJjAgCtHCJS5ZRf6oJGj2QVcqc6cjvEFWsCuOKB4KAjktauWxAAABDwAAAAdzc2gtcnNhAAABALdnEil8XIFkcgLZgYwS2cIQPHetUzMNxYCqzk7mSfVpCaIYNTr27RG+f+sD0cerdAIUUvhCT7iA82/Y7wzwkO2RUBi61ATfw9DDPPRQTDfix1SSRwbmPB/nVI1HlPMCEs6y48PFaBZqXwJPS3qycgSxoTBhaLCLzT+r6HRaibY7kiRLDeL3/WHyasK2PRdcYJ6KrLd0ctQcUHZCLK3fJfMfuQRg8MZLVrmK3fHStCXHpRFueRxUhZjaiS9evA/NtzEQhf46JDClQ2rLYpSqSg7QUR/rKwqWWyMuQkOHmlJw797VVa+ZzpUFXP7ekWel3FaBj8IHiimIA7Jm6dOCLm4= tests/test_ecdsa_256.key.pub
diff --git a/tests/test_ed25519.key-cert.pub b/tests/test_ed25519.key-cert.pub
new file mode 100644
index 00000000..4e01415a
--- /dev/null
+++ b/tests/test_ed25519.key-cert.pub
@@ -0,0 +1 @@
+ssh-ed25519-cert-v01@openssh.com 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 tests/test_ed25519.key.pub
diff --git a/tests/test_pkey.py b/tests/test_pkey.py
index 9bb3c44c..80843222 100644
--- a/tests/test_pkey.py
+++ b/tests/test_pkey.py
@@ -480,3 +480,30 @@ class KeyTest(unittest.TestCase):
             self.assert_keyfile_is_encrypted(newfile)
         finally:
             os.remove(newfile)
+
+    def test_certificates(self):
+        # PKey.load_certificate
+        key = RSAKey.from_private_key_file(test_path('test_rsa.key'))
+        self.assertTrue(key.public_blob is None)
+        key.load_certificate(test_path('test_rsa.key-cert.pub'))
+        self.assertTrue(key.public_blob is not None)
+        self.assertEqual(key.public_blob.key_type, 'ssh-rsa-cert-v01@openssh.com')
+        self.assertEqual(key.public_blob.comment, 'test_rsa.key.pub')
+        # Delve into blob contents, for test purposes
+        msg = Message(key.public_blob.key_blob)
+        self.assertEqual(msg.get_text(), 'ssh-rsa-cert-v01@openssh.com')
+        nonce = msg.get_string()
+        e = msg.get_mpint()
+        n = msg.get_mpint()
+        self.assertEqual(e, key.public_numbers.e)
+        self.assertEqual(n, key.public_numbers.n)
+        # Serial number
+        self.assertEqual(msg.get_int64(), 1234)
+
+        # Prevented from loading certificate that doesn't match
+        key1 = Ed25519Key.from_private_key_file(test_path('test_ed25519.key'))
+        self.assertRaises(
+            ValueError,
+            key1.load_certificate,
+            test_path('test_rsa.key-cert.pub'),
+        )
diff --git a/tests/test_rsa.key-cert.pub b/tests/test_rsa.key-cert.pub
new file mode 100644
index 00000000..7487ab66
--- /dev/null
+++ b/tests/test_rsa.key-cert.pub
@@ -0,0 +1 @@
+ssh-rsa-cert-v01@openssh.com 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 test_rsa.key.pub
diff --git a/tests/test_rsa.key.pub b/tests/test_rsa.key.pub
new file mode 100644
index 00000000..bfa1e150
--- /dev/null
+++ b/tests/test_rsa.key.pub
@@ -0,0 +1 @@
+ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEA049W6geFpmsljTwfvI1UmKWWJPNFI74+vNKTk4dmzkQY2yAMs6FhlvhlI8ysU4oj71ZsRYMecHbBbxdN79+JRFVYTKaLqjwGENeTd+yv4q+V2PvZv3fLnzApI3l7EJCqhWwJUHJ1jAkZzqDx0tyOL4uoZpww3nmE0kb3y21tH4c=
diff --git a/tests/util.py b/tests/util.py
index b546a7e1..c1b43da8 100644
--- a/tests/util.py
+++ b/tests/util.py
@@ -4,4 +4,3 @@ root_path = os.path.dirname(os.path.realpath(__file__))
 
 def test_path(filename):
     return os.path.join(root_path, filename)
-