Merge pull request #227 from calebstewart/issue-91-paramiko-ng

Add support for SSHAgent and Key Types outside of RSA

CHANGELOG.md

@@ -11,6 +11,8 @@ and simply didn't have the time to go back and retroactively create one.
 
 ### Changed
 - Fixed parsing of `--ssl` argument in main entrypoint ([#225](https://github.com/calebstewart/pwncat/issues/225))
+- Replaced `paramiko` with `paramiko-ng`
+- Utilized Paramiko SSHClient which will also utilize the SSHAgent if available by default and supports key types aside from RSA ([#91](https://github.com/calebstewart/pwncat/issues/91))
 
 ## [0.5.1] - 2021-12-07
 Minor bug fixes. Mainly typos from changing the package name.

poetry.lock

@@ -120,7 +120,7 @@ test = ["flake8 (==3.7.8)", "hypothesis (==3.55.3)"]
 
 [[package]]
 name = "cryptography"
-version = "3.4.7"
+version = "36.0.1"
 description = "cryptography is a package which provides cryptographic recipes and primitives to Python developers."
 category = "main"
 optional = false
@@ -131,11 +131,11 @@ cffi = ">=1.12"
 
 [package.extras]
 docs = ["sphinx (>=1.6.5,!=1.8.0,!=3.1.0,!=3.1.1)", "sphinx-rtd-theme"]
-docstest = ["doc8", "pyenchant (>=1.6.11)", "twine (>=1.12.0)", "sphinxcontrib-spelling (>=4.0.1)"]
+docstest = ["pyenchant (>=1.6.11)", "twine (>=1.12.0)", "sphinxcontrib-spelling (>=4.0.1)"]
 pep8test = ["black", "flake8", "flake8-import-order", "pep8-naming"]
-sdist = ["setuptools-rust (>=0.11.4)"]
+sdist = ["setuptools_rust (>=0.11.4)"]
 ssh = ["bcrypt (>=3.1.5)"]
-test = ["pytest (>=6.0)", "pytest-cov", "pytest-subtests", "pytest-xdist", "pretend", "iso8601", "pytz", "hypothesis (>=1.11.4,!=3.79.2)"]
+test = ["pytest (>=6.2.0)", "pytest-cov", "pytest-subtests", "pytest-xdist", "pretend", "iso8601", "pytz", "hypothesis (>=1.11.4,!=3.79.2)"]
 
 [[package]]
 name = "docutils"
@@ -261,23 +261,20 @@ python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
 pyparsing = ">=2.0.2"
 
 [[package]]
-name = "paramiko"
+name = "paramiko-ng"
-version = "2.7.2"
+version = "2.8.8"
 description = "SSH2 protocol library"
 category = "main"
 optional = false
-python-versions = "*"
+python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
 
 [package.dependencies]
-bcrypt = ">=3.1.3"
+bcrypt = ">=3"
-cryptography = ">=2.5"
+cryptography = ">=1.6"
-pynacl = ">=1.0.1"
 
 [package.extras]
-all = ["pyasn1 (>=0.1.7)", "pynacl (>=1.0.1)", "bcrypt (>=3.1.3)", "invoke (>=1.3)", "gssapi (>=1.4.1)", "pywin32 (>=2.1.8)"]
+ed25519 = ["pynacl"]
-ed25519 = ["pynacl (>=1.0.1)", "bcrypt (>=3.1.3)"]
+gssapi = ["gssapi", "pyasn1"]
-gssapi = ["pyasn1 (>=0.1.7)", "gssapi (>=1.4.1)", "pywin32 (>=2.1.8)"]
-invoke = ["invoke (>=1.3)"]
 
 [[package]]
 name = "persistent"
@@ -787,7 +784,7 @@ testing = ["coverage (>=5.0.3)", "zope.event", "zope.testing"]
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.9"
-content-hash = "9357cb6dd124d9b201849436e710ae4baec36f65104fa505e5e155c60d602e79"
+content-hash = "23945db2620e31067d3b8810462ebaa6627fde4220ed01d49ba009e89962a725"
 
 [metadata.files]
 alabaster = [
@@ -931,18 +928,26 @@ commonmark = [
     {file = "commonmark-0.9.1.tar.gz", hash = "sha256:452f9dc859be7f06631ddcb328b6919c67984aca654e5fefb3914d54691aed60"},
 ]
 cryptography = [
-    {file = "cryptography-3.4.7-cp36-abi3-macosx_10_10_x86_64.whl", hash = "sha256:3d8427734c781ea5f1b41d6589c293089704d4759e34597dce91014ac125aad1"},
+    {file = "cryptography-36.0.1-cp36-abi3-macosx_10_10_universal2.whl", hash = "sha256:73bc2d3f2444bcfeac67dd130ff2ea598ea5f20b40e36d19821b4df8c9c5037b"},
-    {file = "cryptography-3.4.7-cp36-abi3-macosx_11_0_arm64.whl", hash = "sha256:8e56e16617872b0957d1c9742a3f94b43533447fd78321514abbe7db216aa250"},
+    {file = "cryptography-36.0.1-cp36-abi3-macosx_10_10_x86_64.whl", hash = "sha256:2d87cdcb378d3cfed944dac30596da1968f88fb96d7fc34fdae30a99054b2e31"},
-    {file = "cryptography-3.4.7-cp36-abi3-manylinux2010_x86_64.whl", hash = "sha256:37340614f8a5d2fb9aeea67fd159bfe4f5f4ed535b1090ce8ec428b2f15a11f2"},
+    {file = "cryptography-36.0.1-cp36-abi3-manylinux_2_12_x86_64.manylinux2010_x86_64.whl", hash = "sha256:74d6c7e80609c0f4c2434b97b80c7f8fdfaa072ca4baab7e239a15d6d70ed73a"},
-    {file = "cryptography-3.4.7-cp36-abi3-manylinux2014_aarch64.whl", hash = "sha256:240f5c21aef0b73f40bb9f78d2caff73186700bf1bc6b94285699aff98cc16c6"},
+    {file = "cryptography-36.0.1-cp36-abi3-manylinux_2_17_aarch64.manylinux2014_aarch64.manylinux_2_24_aarch64.whl", hash = "sha256:6c0c021f35b421ebf5976abf2daacc47e235f8b6082d3396a2fe3ccd537ab173"},
-    {file = "cryptography-3.4.7-cp36-abi3-manylinux2014_x86_64.whl", hash = "sha256:1e056c28420c072c5e3cb36e2b23ee55e260cb04eee08f702e0edfec3fb51959"},
+    {file = "cryptography-36.0.1-cp36-abi3-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:5d59a9d55027a8b88fd9fd2826c4392bd487d74bf628bb9d39beecc62a644c12"},
-    {file = "cryptography-3.4.7-cp36-abi3-win32.whl", hash = "sha256:0f1212a66329c80d68aeeb39b8a16d54ef57071bf22ff4e521657b27372e327d"},
+    {file = "cryptography-36.0.1-cp36-abi3-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:0a817b961b46894c5ca8a66b599c745b9a3d9f822725221f0e0fe49dc043a3a3"},
-    {file = "cryptography-3.4.7-cp36-abi3-win_amd64.whl", hash = "sha256:de4e5f7f68220d92b7637fc99847475b59154b7a1b3868fb7385337af54ac9ca"},
+    {file = "cryptography-36.0.1-cp36-abi3-manylinux_2_24_x86_64.whl", hash = "sha256:94ae132f0e40fe48f310bba63f477f14a43116f05ddb69d6fa31e93f05848ae2"},
-    {file = "cryptography-3.4.7-pp36-pypy36_pp73-manylinux2010_x86_64.whl", hash = "sha256:26965837447f9c82f1855e0bc8bc4fb910240b6e0d16a664bb722df3b5b06873"},
+    {file = "cryptography-36.0.1-cp36-abi3-musllinux_1_1_aarch64.whl", hash = "sha256:7be0eec337359c155df191d6ae00a5e8bbb63933883f4f5dffc439dac5348c3f"},
-    {file = "cryptography-3.4.7-pp36-pypy36_pp73-manylinux2014_x86_64.whl", hash = "sha256:eb8cc2afe8b05acbd84a43905832ec78e7b3873fb124ca190f574dca7389a87d"},
+    {file = "cryptography-36.0.1-cp36-abi3-musllinux_1_1_x86_64.whl", hash = "sha256:e0344c14c9cb89e76eb6a060e67980c9e35b3f36691e15e1b7a9e58a0a6c6dc3"},
-    {file = "cryptography-3.4.7-pp37-pypy37_pp73-manylinux2010_x86_64.whl", hash = "sha256:7ec5d3b029f5fa2b179325908b9cd93db28ab7b85bb6c1db56b10e0b54235177"},
+    {file = "cryptography-36.0.1-cp36-abi3-win32.whl", hash = "sha256:4caa4b893d8fad33cf1964d3e51842cd78ba87401ab1d2e44556826df849a8ca"},
-    {file = "cryptography-3.4.7-pp37-pypy37_pp73-manylinux2014_x86_64.whl", hash = "sha256:ee77aa129f481be46f8d92a1a7db57269a2f23052d5f2433b4621bb457081cc9"},
+    {file = "cryptography-36.0.1-cp36-abi3-win_amd64.whl", hash = "sha256:391432971a66cfaf94b21c24ab465a4cc3e8bf4a939c1ca5c3e3a6e0abebdbcf"},
-    {file = "cryptography-3.4.7.tar.gz", hash = "sha256:3d10de8116d25649631977cb37da6cbdd2d6fa0e0281d014a5b7d337255ca713"},
+    {file = "cryptography-36.0.1-pp37-pypy37_pp73-manylinux_2_12_x86_64.manylinux2010_x86_64.whl", hash = "sha256:bb5829d027ff82aa872d76158919045a7c1e91fbf241aec32cb07956e9ebd3c9"},
+    {file = "cryptography-36.0.1-pp37-pypy37_pp73-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:ebc15b1c22e55c4d5566e3ca4db8689470a0ca2babef8e3a9ee057a8b82ce4b1"},
+    {file = "cryptography-36.0.1-pp37-pypy37_pp73-manylinux_2_24_x86_64.whl", hash = "sha256:596f3cd67e1b950bc372c33f1a28a0692080625592ea6392987dba7f09f17a94"},
+    {file = "cryptography-36.0.1-pp38-pypy38_pp73-macosx_10_10_x86_64.whl", hash = "sha256:30ee1eb3ebe1644d1c3f183d115a8c04e4e603ed6ce8e394ed39eea4a98469ac"},
+    {file = "cryptography-36.0.1-pp38-pypy38_pp73-manylinux_2_12_x86_64.manylinux2010_x86_64.whl", hash = "sha256:ec63da4e7e4a5f924b90af42eddf20b698a70e58d86a72d943857c4c6045b3ee"},
+    {file = "cryptography-36.0.1-pp38-pypy38_pp73-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:ca238ceb7ba0bdf6ce88c1b74a87bffcee5afbfa1e41e173b1ceb095b39add46"},
+    {file = "cryptography-36.0.1-pp38-pypy38_pp73-manylinux_2_24_x86_64.whl", hash = "sha256:ca28641954f767f9822c24e927ad894d45d5a1e501767599647259cbf030b903"},
+    {file = "cryptography-36.0.1-pp38-pypy38_pp73-win_amd64.whl", hash = "sha256:39bdf8e70eee6b1c7b289ec6e5d84d49a6bfa11f8b8646b5b3dfe41219153316"},
+    {file = "cryptography-36.0.1.tar.gz", hash = "sha256:53e5c1dc3d7a953de055d77bef2ff607ceef7a2aac0353b5d630ab67f7423638"},
 ]
 docutils = [
     {file = "docutils-0.16-py2.py3-none-any.whl", hash = "sha256:0c5b78adfbf7762415433f5515cd5c9e762339e23369dbe8000d84a4bf4ab3af"},
@@ -1052,9 +1057,9 @@ packaging = [
     {file = "packaging-20.9-py2.py3-none-any.whl", hash = "sha256:67714da7f7bc052e064859c05c595155bd1ee9f69f76557e21f051443c20947a"},
     {file = "packaging-20.9.tar.gz", hash = "sha256:5b327ac1320dc863dca72f4514ecc086f31186744b84a230374cc1fd776feae5"},
 ]
-paramiko = [
+paramiko-ng = [
-    {file = "paramiko-2.7.2-py2.py3-none-any.whl", hash = "sha256:4f3e316fef2ac628b05097a637af35685183111d4bc1b5979bd397c2ab7b5898"},
+    {file = "paramiko-ng-2.8.8.tar.gz", hash = "sha256:d11191bda27dea3d4cd080c41912bd286ba3879c49851b6c7fc286c2fd0d4497"},
-    {file = "paramiko-2.7.2.tar.gz", hash = "sha256:7f36f4ba2c0d81d219f4595e35f70d56cc94f9ac40a6acdf51d6ca210ce65035"},
+    {file = "paramiko_ng-2.8.8-py2.py3-none-any.whl", hash = "sha256:21c8ad4d86006862ef32f6a1f68e563d3dd07fef4336b89a61d2f4c465806e8e"},
 ]
 persistent = [
     {file = "persistent-4.7.0-cp27-cp27m-macosx_10_14_x86_64.whl", hash = "sha256:ed939f58937f43a67a0f60abb0057e7f31e90d35b6a215159b04248368696930"},

pwncat/channel/ssh.py

@@ -8,7 +8,7 @@ An optional port argument is also accepted.
 """
 import os
 import socket
-from typing import Optional
+from typing import Union, TextIO, Optional
 
 import paramiko
 from prompt_toolkit import prompt
@@ -46,66 +46,32 @@ class Ssh(Channel):
             password = prompt("Password: ", is_password=True)
 
         try:
-            # Connect to the remote host's ssh server
+            client = paramiko.client.SSHClient()
-            sock = socket.create_connection((host, port))
+            client.set_missing_host_key_policy(paramiko.client.AutoAddPolicy)
-        except Exception as exc:
-            raise ChannelError(self, str(exc))
 
-        # Create a paramiko SSH transport layer around the socket
+            client.connect(
-        t = paramiko.Transport(sock)
+                hostname=host,
-        try:
+                port=port,
-            t.start_client()
+                username=user,
-        except paramiko.SSHException:
+                password=password,
-            sock.close()
+                pkey=load_private_key(identity),
-            raise ChannelError(self, "ssh negotiation failed")
+                allow_agent=True,
-
+                look_for_keys=False,
-        if identity is not None:
-            try:
-                # Load the private key for the user
-                if isinstance(identity, str):
-                    key = paramiko.RSAKey.from_private_key_file(
-                        os.path.expanduser(identity)
             )
-                else:
-                    key = paramiko.RSAKey.from_private_key(identity)
-            except paramiko.ssh_exception.SSHException:
-                password = prompt("RSA Private Key Passphrase: ", is_password=True)
-                try:
-                    if isinstance(identity, str):
-                        key = paramiko.RSAKey.from_private_key_file(identity, password)
-                    else:
-                        # Seek back to the beginning of the file (the above load read the whole file)
-                        identity.seek(0)
-                        key = paramiko.RSAKey.from_private_key(identity, password)
-                except paramiko.ssh_exception.SSHException:
-                    raise ChannelError(self, "invalid private key or passphrase")
 
-            # Attempt authentication
+            columns, rows = os.get_terminal_size(0)
-            try:
+            shell = client.invoke_shell(width=columns, height=rows)
-                t.auth_publickey(user, key)
+            shell.setblocking(0)
-            except paramiko.ssh_exception.AuthenticationException as exc:
-                raise ChannelError(self, str(exc))
-        else:
-            try:
-                t.auth_password(user, password)
-            except paramiko.ssh_exception.AuthenticationException as exc:
-                raise ChannelError(self, str(exc))
 
-        if not t.is_authenticated():
+            self.client = shell
-            t.close()
-            sock.close()
-            raise ChannelError(self, "authentication failed")
-
-        # Open an interactive session
-        chan = t.open_session()
-        chan.get_pty()
-        chan.invoke_shell()
-        chan.setblocking(0)
-
-        self.client = chan
             self.address = (host, port)
             self._connected = True
 
+        except paramiko.ssh_exception.AuthenticationException as exc:
+            raise ChannelError(self, f"ssh authentication failed: {str(exc)}") from exc
+        except (paramiko.ssh_exception.SSHException, socket.error) as exc:
+            raise ChannelError(self, f"ssh connection failed: {str(exc)}") from exc
+
     @property
     def connected(self):
         return self._connected
@@ -153,3 +119,36 @@ class Ssh(Channel):
             pass
 
         return data
+
+
+def load_private_key(identity: Union[str, TextIO], passphrase: str = None):
+    """Load a private key and return the appropriate PKey object"""
+
+    if identity is None:
+        return None
+
+    try:
+        if isinstance(identity, str):
+            return paramiko.pkey.load_private_key_file(
+                os.path.expanduser(identity), password=passphrase
+            )
+
+        identity.seek(0)
+        return paramiko.pkey.load_private_key(identity.read(), password=passphrase)
+    except paramiko.PasswordRequiredException:
+        # Bad passphrase
+        if passphrase is not None:
+            raise
+
+        try:
+            # No passphrase, prompt for one
+            passphrase = prompt("Private Key Passphrase: ", is_password=True)
+        except KeyboardInterrupt:
+            passphrase = None
+
+        # No passphrase given, re-raise
+        if passphrase is None:
+            raise
+
+        # Try again with the given passphrase
+        return load_private_key(identity, passphrase=passphrase)

pwncat/facts/__init__.py

@@ -5,9 +5,8 @@ should not generally need to use these types except as reference
 when interacting with data returned by an enumeration module.
 """
 import time
-import pathlib
-import tempfile
 import subprocess
+from io import StringIO
 from typing import Callable, Optional
 
 import rich.markup
@@ -356,19 +355,13 @@ class PrivateKey(Implant):
         else:
             raise ModuleFailed(f"unknown username for uid={self.uid}")
 
-        with tempfile.NamedTemporaryFile("w") as filp:
-            filp.write(self.content)
-            filp.flush()
-
-            pathlib.Path(filp.name).chmod(0o600)
-
         try:
             # Connect via SSH
             session = manager.create_session(
                 "linux",
                 host=target.public_address[0],
                 user=user.name,
-                    identity=filp.name,
+                identity=StringIO(self.content + "\n"),
             )
         except (ChannelError, PlatformError) as exc:
             manager.log(

pyproject.toml

@@ -40,8 +40,9 @@ rich = "^10.4.0"
 python-rapidjson = "^1.0"
 ZODB3 = "^3.11.0"
 zodburi = "^2.5.0"
-paramiko = "^2.7.2"
 Jinja2 = "^3.0.1"
+paramiko-ng = "^2.8.8"
+PyNaCl = "^1.4.0"
 
 [tool.poetry.dev-dependencies]
 isort = "^5.8.0"