Pkey from memory (#329)

* Added private key auth from memory implementation for native client
* Updated gitignore
* Updated parallel clients to use in-memory pkey data
* Added tests
* Bump requirements
* Updated changelog
* Updated documentation

Author: pkittenis

.gitignore

@@ -47,3 +47,5 @@ doc/_build
 
 tests/unit_test_cert_key-cert.pub
 tests/embedded_server/principals
+tests/embedded_server/sshd_config_*
+tests/embedded_server/*.pid

Changelog.rst

@@ -1,6 +1,19 @@
 Change Log
 ============
 
+2.8.0
++++++
+
+Changes
+--------
+
+* All clients now support private key data as bytes in ``pkey`` parameter for authentication from in-memory private key
+  data - #317. See `documentation <https://parallel-ssh.readthedocs.io/en/latest/advanced.html#in-memory-private-keys>`_
+  for examples.
+* Parallel clients now read a provided private key path only once and use in-memory data for authentication to avoid
+  reading same file multiple times, if a path is provided.
+
+
 2.7.1
 +++++
 

doc/advanced.rst

@@ -24,6 +24,24 @@ A private key can also be provided programmatically.
 Where ``my_key`` is a private key file under `.ssh` in the user's home directory.
 
 
+In-Memory Private Keys
+========================
+
+Private key data can also be provided as bytes for authentication from in-memory private keys.
+
+.. code-block:: python
+
+   from pssh.clients import ParallelSSHClient
+
+   pkey_data = b"""-----BEGIN RSA PRIVATE KEY-----
+   <key data>
+   -----END RSA PRIVATE KEY-----
+   """
+   client = ParallelSSHClient(hosts, pkey=pkey_data)
+
+Private key data provided this way *must* be in bytes. This is supported by all parallel and single host clients.
+
+
 Native Clients
 ***************
 

pssh/clients/base/single.py

@@ -28,7 +28,7 @@
 from ssh2.exceptions import AgentConnectionError, AgentListIdentitiesError, \
     AgentAuthenticationError, AgentGetIdentityError
 
-from ..common import _validate_pkey_path
+from ..common import _validate_pkey
 from ...constants import DEFAULT_RETRIES, RETRY_DELAY
 from ..reader import ConcurrentRWBuffer
 from ...exceptions import UnknownHostError, AuthenticationError, \
@@ -182,12 +182,15 @@ def __init__(self, host,
         self.session = None
         self._host = proxy_host if proxy_host else host
         self._port = proxy_port if proxy_port else self.port
-        self.pkey = _validate_pkey_path(pkey, self.host)
+        self.pkey = _validate_pkey(pkey)
         self.identity_auth = identity_auth
         self._keepalive_greenlet = None
         self.ipv6_only = ipv6_only
         self._init()
 
+    def _pkey_from_memory(self, pkey_data):
+        raise NotImplementedError
+
     def _init(self):
         self._connect(self._host, self._port)
         self._init_session()
@@ -309,7 +312,7 @@ def _identity_auth(self):
                 "Trying to authenticate with identity file %s",
                 identity_file)
             try:
-                self._pkey_auth(identity_file, password=self.password)
+                self._pkey_file_auth(identity_file, password=self.password)
             except Exception as ex:
                 logger.debug(
                     "Authentication with identity file %s failed with %s, "
@@ -331,8 +334,8 @@ def _keepalive(self):
     def auth(self):
         if self.pkey is not None:
             logger.debug(
-                "Proceeding with private key file authentication")
-            return self._pkey_auth(self.pkey, password=self.password)
+                "Proceeding with private key authentication")
+            return self._pkey_auth(self.pkey)
         if self.allow_agent:
             try:
                 self._agent_auth()
@@ -364,7 +367,17 @@ def _agent_auth(self):
     def _password_auth(self):
         raise NotImplementedError
 
-    def _pkey_auth(self, pkey_file, password=None):
+    def _pkey_auth(self, pkey):
+        _pkey = pkey
+        if isinstance(pkey, str):
+            logger.debug("Private key is provided as str, loading from private key file path")
+            with open(pkey, 'rb') as fh:
+                _pkey = fh.read()
+        elif isinstance(pkey, bytes):
+            logger.debug("Private key is provided in bytes, using as private key data")
+        return self._pkey_from_memory(_pkey)
+
+    def _pkey_file_auth(self, pkey_file, password=None):
         raise NotImplementedError
 
     def _open_session(self):

pssh/clients/common.py

@@ -20,7 +20,7 @@
 from ..exceptions import PKeyFileError
 
 
-def _validate_pkey_path(pkey, host=None):
+def _validate_pkey_path(pkey):
     if pkey is None:
         return
     pkey = os.path.normpath(os.path.expanduser(pkey))
@@ -31,3 +31,11 @@ def _validate_pkey_path(pkey, host=None):
         ex = PKeyFileError(msg, pkey)
         raise ex
     return pkey
+
+
+def _validate_pkey(pkey):
+    if pkey is None:
+        return
+    if isinstance(pkey, str):
+        return _validate_pkey_path(pkey)
+    return pkey

pssh/clients/native/parallel.py

@@ -18,7 +18,7 @@
 import logging
 
 from .single import SSHClient
-from ..common import _validate_pkey_path
+from ..common import _validate_pkey
 from ..base.parallel import BaseParallelSSHClient
 from ...constants import DEFAULT_RETRIES, RETRY_DELAY
 from ...exceptions import HostArgumentError
@@ -50,9 +50,11 @@ def __init__(self, hosts, user=None, password=None, port=22, pkey=None,
         :param port: (Optional) Port number to use for SSH connection. Defaults
           to 22.
         :type port: int
-        :param pkey: Private key file path to use. Path must be either absolute
+        :param pkey: Private key file path or private key data to use.
+          Paths must be str type and either absolute
           path or relative to user home directory like ``~/<path>``.
-        :type pkey: str
+          Bytes type input is used as private key data for authentication.
+        :type pkey: str or bytes
         :param num_retries: (Optional) Number of connection and authentication
           attempts before the client gives up. Defaults to 3.
         :type num_retries: int
@@ -127,10 +129,10 @@ def __init__(self, hosts, user=None, password=None, port=22, pkey=None,
             identity_auth=identity_auth,
             ipv6_only=ipv6_only,
         )
-        self.pkey = _validate_pkey_path(pkey)
+        self.pkey = _validate_pkey(pkey)
         self.proxy_host = proxy_host
         self.proxy_port = proxy_port
-        self.proxy_pkey = _validate_pkey_path(proxy_pkey)
+        self.proxy_pkey = _validate_pkey(proxy_pkey)
         self.proxy_user = proxy_user
         self.proxy_password = proxy_password
         self.forward_ssh_agent = forward_ssh_agent
@@ -235,9 +237,14 @@ def _make_ssh_client(self, host_i, host):
            or self._host_clients[(host_i, host)] is None:
             _user, _port, _password, _pkey, proxy_host, proxy_port, proxy_user, \
                 proxy_password, proxy_pkey = self._get_host_config_values(host_i, host)
+            if isinstance(self.pkey, str):
+                with open(_pkey, 'rb') as fh:
+                    _pkey_data = fh.read()
+            else:
+                _pkey_data = _pkey
             _client = SSHClient(
                 host, user=_user, password=_password, port=_port,
-                pkey=_pkey, num_retries=self.num_retries,
+                pkey=_pkey_data, num_retries=self.num_retries,
                 timeout=self.timeout,
                 allow_agent=self.allow_agent, retry_delay=self.retry_delay,
                 proxy_host=proxy_host,

pssh/clients/native/single.py

@@ -75,7 +75,8 @@ def __init__(self, host,
         :param pkey: Private key file path to use for authentication. Path must
           be either absolute path or relative to user home directory
           like ``~/<path>``.
-        :type pkey: str
+          Bytes type input is used as private key data for authentication.
+        :type pkey: str or bytes
         :param num_retries: (Optional) Number of connection and authentication
           attempts before the client gives up. Defaults to 3.
         :type num_retries: int
@@ -239,12 +240,19 @@ def _keepalive(self):
     def _agent_auth(self):
         self.session.agent_auth(self.user)
 
-    def _pkey_auth(self, pkey_file, password=None):
+    def _pkey_file_auth(self, pkey_file, password=None):
         self.session.userauth_publickey_fromfile(
             self.user,
             pkey_file,
             passphrase=password if password is not None else b'')
 
+    def _pkey_from_memory(self, pkey_data):
+        self.session.userauth_publickey_frommemory(
+            self.user,
+            pkey_data,
+            passphrase=self.password if self.password is not None else b'',
+        )
+
     def _password_auth(self):
         self.session.userauth_password(self.user, self.password)
 

pssh/clients/ssh/parallel.py

@@ -18,7 +18,7 @@
 import logging
 
 from .single import SSHClient
-from ..common import _validate_pkey_path
+from ..common import _validate_pkey_path, _validate_pkey
 from ..base.parallel import BaseParallelSSHClient
 from ...constants import DEFAULT_RETRIES, RETRY_DELAY
 
@@ -54,7 +54,8 @@ def __init__(self, hosts, user=None, password=None, port=22, pkey=None,
         :type port: int
         :param pkey: Private key file path to use. Path must be either absolute
           path or relative to user home directory like ``~/<path>``.
-        :type pkey: str
+          Bytes type input is used as private key data for authentication.
+        :type pkey: str or bytes
         :param cert_file: Public key signed certificate file to use for
           authentication. The corresponding private key must also be provided
           via ``pkey`` parameter.
@@ -141,7 +142,7 @@ def __init__(self, hosts, user=None, password=None, port=22, pkey=None,
             identity_auth=identity_auth,
             ipv6_only=ipv6_only,
         )
-        self.pkey = _validate_pkey_path(pkey)
+        self.pkey = _validate_pkey(pkey)
         self.cert_file = _validate_pkey_path(cert_file)
         self.forward_ssh_agent = forward_ssh_agent
         self.gssapi_auth = gssapi_auth
@@ -235,9 +236,14 @@ def _make_ssh_client(self, host_i, host):
            or self._host_clients[(host_i, host)] is None:
             _user, _port, _password, _pkey, _, _, _, _, _ = \
                 self._get_host_config_values(host_i, host)
+            if isinstance(self.pkey, str):
+                with open(_pkey, 'rb') as fh:
+                    _pkey_data = fh.read()
+            else:
+                _pkey_data = _pkey
             _client = SSHClient(
                 host, user=_user, password=_password, port=_port,
-                pkey=_pkey,
+                pkey=_pkey_data,
                 cert_file=self.cert_file,
                 num_retries=self.num_retries,
                 timeout=self.timeout,

pssh/clients/ssh/single.py

@@ -20,7 +20,8 @@
 from gevent import sleep, spawn, Timeout as GTimeout, joinall
 from ssh import options
 from ssh.session import Session, SSH_READ_PENDING, SSH_WRITE_PENDING
-from ssh.key import import_privkey_file, import_cert_file, copy_cert_to_privkey
+from ssh.key import import_privkey_file, import_cert_file, copy_cert_to_privkey,\
+    import_privkey_base64
 from ssh.exceptions import EOF
 from ssh.error_codes import SSH_AGAIN
 
@@ -62,7 +63,8 @@ def __init__(self, host,
         :param pkey: Private key file path to use for authentication. Path must
           be either absolute path or relative to user home directory
           like ``~/<path>``.
-        :type pkey: str
+          Bytes type input is used as private key data for authentication.
+        :type pkey: str or bytes
         :param cert_file: Public key signed certificate file to use for
           authentication. The corresponding private key must also be provided
           via ``pkey`` parameter.
@@ -106,7 +108,7 @@ def __init__(self, host,
         :raises: :py:class:`pssh.exceptions.PKeyFileError` on errors finding
           provided private key.
         """
-        self.cert_file = _validate_pkey_path(cert_file, host)
+        self.cert_file = _validate_pkey_path(cert_file)
         self.gssapi_auth = gssapi_auth
         self.gssapi_server_identity = gssapi_server_identity
         self.gssapi_client_identity = gssapi_client_identity
@@ -175,13 +177,22 @@ def auth(self):
     def _password_auth(self):
         self.session.userauth_password(self.user, self.password)
 
-    def _pkey_auth(self, pkey_file, password=None):
+    def _pkey_file_auth(self, pkey_file, password=None):
         pkey = import_privkey_file(pkey_file, passphrase=password if password is not None else '')
+        return self._pkey_obj_auth(pkey)
+
+    def _pkey_obj_auth(self, pkey):
         if self.cert_file is not None:
             logger.debug("Certificate file set - trying certificate authentication")
             self._import_cert_file(pkey)
         self.session.userauth_publickey(pkey)
 
+    def _pkey_from_memory(self, pkey_data):
+        _pkey = import_privkey_base64(
+            pkey_data,
+            passphrase=self.password if self.password is not None else b'')
+        return self._pkey_obj_auth(_pkey)
+
     def _import_cert_file(self, pkey):
         cert_key = import_cert_file(self.cert_file)
         self.session.userauth_try_publickey(cert_key)

requirements.txt

@@ -1,3 +1,3 @@
 gevent>=1.3.0
-ssh2-python>=0.22.0
+ssh2-python>=0.27.0
 ssh-python>=0.9.0