ssh: T8098: remove support for deprecated "rijndael-cbc@lysator.liu.se" cipher

According to an Arch Linux forum discussion, the cipher
rijndael-cbc@lysator.liu.se was removed in OpenSSH 6.7.

References:
- https://bbs.archlinux.org/viewtopic.php?id=188613
- https://www.openssh.org/txt/release-6.7
- https://github.com/openssh/openssh-portable/commit/03e93c753d7c223063a

4 files changed, 34 insertions, 4 deletions

diff --git a/interface-definitions/include/version/ssh-version.xml.i b/interface-definitions/include/version/ssh-version.xml.i
index 0f25caf98..05cf431a7 100644
--- a/interface-definitions/include/version/ssh-version.xml.i
+++ b/interface-definitions/include/version/ssh-version.xml.i
@@ -1,3 +1,3 @@
 <!-- include start from include/version/ssh-version.xml.i -->
-<syntaxVersion component='ssh' version='2'></syntaxVersion>
+<syntaxVersion component='ssh' version='3'></syntaxVersion>
 <!-- include end -->
diff --git a/interface-definitions/service_ssh.xml.in b/interface-definitions/service_ssh.xml.in
index c659a7db7..4d10de646 100644
--- a/interface-definitions/service_ssh.xml.in
+++ b/interface-definitions/service_ssh.xml.in
@@ -41,10 +41,10 @@
               <help>Allowed ciphers</help>
               <completionHelp>
                 <!-- generated by ssh -Q cipher | tr '\n' ' ' as this will not change dynamically  -->
-                <list>3des-cbc aes128-cbc aes192-cbc aes256-cbc rijndael-cbc@lysator.liu.se aes128-ctr aes192-ctr aes256-ctr aes128-gcm@openssh.com aes256-gcm@openssh.com chacha20-poly1305@openssh.com</list>
+                <list>3des-cbc aes128-cbc aes192-cbc aes256-cbc aes128-ctr aes192-ctr aes256-ctr aes128-gcm@openssh.com aes256-gcm@openssh.com chacha20-poly1305@openssh.com</list>
               </completionHelp>
                 <constraint>
-                  <regex>(3des-cbc|aes128-cbc|aes192-cbc|aes256-cbc|rijndael-cbc@lysator.liu.se|aes128-ctr|aes192-ctr|aes256-ctr|aes128-gcm@openssh.com|aes256-gcm@openssh.com|chacha20-poly1305@openssh.com)</regex>
+                  <regex>(3des-cbc|aes128-cbc|aes192-cbc|aes256-cbc|aes128-ctr|aes192-ctr|aes256-ctr|aes128-gcm@openssh.com|aes256-gcm@openssh.com|chacha20-poly1305@openssh.com)</regex>
                 </constraint>
               <multi/>
             </properties>
diff --git a/smoketest/configs/assert/basic-vyos b/smoketest/configs/assert/basic-vyos
index 601051d8f..20363b77f 100644
--- a/smoketest/configs/assert/basic-vyos
+++ b/smoketest/configs/assert/basic-vyos
@@ -85,7 +85,6 @@ set service ssh ciphers 'aes128-ctr'
 set service ssh ciphers 'aes192-ctr'
 set service ssh ciphers 'aes256-ctr'
 set service ssh ciphers 'chacha20-poly1305@openssh.com'
-set service ssh ciphers 'rijndael-cbc@lysator.liu.se'
 set service ssh key-exchange 'curve25519-sha256@libssh.org'
 set service ssh key-exchange 'diffie-hellman-group1-sha1'
 set service ssh key-exchange 'diffie-hellman-group-exchange-sha1'
diff --git a/src/migration-scripts/ssh/2-to-3 b/src/migration-scripts/ssh/2-to-3
new file mode 100644
index 000000000..e18a6aa05
--- /dev/null
+++ b/src/migration-scripts/ssh/2-to-3
@@ -0,0 +1,31 @@
+# Copyright 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/>.
+
+# T8098: rijndael-cbc@lysator.liu.se was removed in OpenSSH 6.7 which is used
+#        starting with VyOS 1.4
+
+from vyos.configtree import ConfigTree
+
+base = ['service', 'ssh']
+
+def migrate(config: ConfigTree) -> None:
+    if not config.exists(base + ['ciphers']):
+        # Nothing to do
+        return
+
+    deprecated_cipher = 'rijndael-cbc@lysator.liu.se'
+    for cipher in config.return_values(base + ['ciphers']):
+        if cipher == deprecated_cipher:
+            config.delete_value(base + ['ciphers'], value=deprecated_cipher)