T5653: Command to display SSH server fingerprint

2 files changed, 90 insertions, 0 deletions

diff --git a/op-mode-definitions/show-ssh.xml.in b/op-mode-definitions/show-ssh.xml.in
new file mode 100644
index 000000000..7b72739c4
--- /dev/null
+++ b/op-mode-definitions/show-ssh.xml.in
@@ -0,0 +1,28 @@
+<?xml version="1.0"?>
+<interfaceDefinition>
+  <node name="show">
+    <children>
+      <node name="ssh">
+        <properties>
+          <help>Show SSH server information</help>
+        </properties>
+        <children>
+          <node name="fingerprints">
+            <properties>
+              <help>Show SSH server public key fingerprints</help>
+            </properties>
+            <command>${vyos_op_scripts_dir}/ssh.py show_fingerprints</command>
+            <children>
+              <node name="ascii">
+                <properties>
+                  <help>Show visual ASCII art representation of the public key</help>
+                </properties>
+                <command>${vyos_op_scripts_dir}/ssh.py show_fingerprints --ascii</command>
+              </node>
+            </children>
+          </node>
+        </children>
+      </node>
+    </children>
+  </node>
+</interfaceDefinition>
diff --git a/src/op_mode/ssh.py b/src/op_mode/ssh.py
new file mode 100755
index 000000000..4de9521b5
--- /dev/null
+++ b/src/op_mode/ssh.py
@@ -0,0 +1,62 @@
+#!/usr/bin/env python3
+#
+# Copyright 2023 VyOS maintainers and contributors <maintainers@vyos.io>
+#
+# This library 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.
+#
+# This library 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 this library.  If not, see <http://www.gnu.org/licenses/>.
+
+import sys
+import glob
+import vyos.opmode
+from vyos.utils.process import cmd
+from vyos.configquery import ConfigTreeQuery
+from tabulate import tabulate
+
+def show_fingerprints(raw: bool, ascii: bool):
+    config = ConfigTreeQuery()
+    if not config.exists("service ssh"):
+        raise vyos.opmode.UnconfiguredSubsystem("SSH server is not enabled.")
+
+    publickeys = glob.glob("/etc/ssh/*.pub")
+
+    if publickeys:
+        keys = []
+        for keyfile in publickeys:
+            try:
+                if ascii:
+                    keydata = cmd("ssh-keygen -l -v -E sha256 -f " + keyfile).splitlines()
+                else:
+                    keydata = cmd("ssh-keygen -l -E sha256 -f " + keyfile).splitlines()
+                type = keydata[0].split(None)[-1].strip("()")
+                key_size = keydata[0].split(None)[0]
+                fingerprint = keydata[0].split(None)[1]
+                comment = keydata[0].split(None)[2:-1][0]
+                if ascii:
+                    ascii_art = "\n".join(keydata[1:])
+                    keys.append({"type": type, "key_size": key_size, "fingerprint": fingerprint, "comment": comment, "ascii_art": ascii_art})
+                else:
+                    keys.append({"type": type, "key_size": key_size, "fingerprint": fingerprint, "comment": comment})
+            except:
+                # Ignore invalid public keys
+                pass
+        if raw:
+            return keys
+        else:
+            headers = {"type": "Type", "key_size": "Key Size", "fingerprint": "Fingerprint", "comment": "Comment", "ascii_art": "ASCII Art"}
+            output = "SSH server public key fingerprints:\n\n" + tabulate(keys, headers=headers, tablefmt="simple")
+            return output
+    else:
+        if raw:
+            return []
+        else:
+            return "No SSH server public keys are found."