T264: IPsec add base64 encoded secret-type feature

Add the ability to configure base64 encoded passwords for
VPN IPSec site-to-site peers

authentication psk PSK secret 'xxxxx=='
authentication psk PSK secret-type <base64|plaintext>

data/templates/ipsec/swanctl.conf.j2

@@ -87,7 +87,13 @@ secrets {
         id-{{ gen_uuid }} = "{{ id }}"
 {%             endfor %}
 {%         endif %}
+{%         if psk_config.secret_type is vyos_defined('base64') %}
+        secret = 0s{{ psk_config.secret }}
+{%         elif psk_config.secret_type is vyos_defined('plaintext') %}
         secret = "{{ psk_config.secret }}"
+{%         else %}
+        secret = "{{ psk_config.secret }}"
+{%         endif %}
     }
 {%     endfor %}
 {% endif %}

interface-definitions/vpn_ipsec.xml.in

@@ -41,6 +41,18 @@
                       </valueHelp>
                     </properties>
                   </leafNode>
+                  <leafNode name="secret-type">
+                    <properties>
+                      <help>Secret type</help>
+                      <completionHelp>
+                        <list>base64 plaintext</list>
+                      </completionHelp>
+                      <constraint>
+                        <regex>(base64|plaintext)</regex>
+                      </constraint>
+                    </properties>
+                    <defaultValue>plaintext</defaultValue>
+                  </leafNode>
                 </children>
               </tagNode>
             </children>

smoketest/scripts/cli/test_vpn_ipsec.py

@@ -14,6 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import base64
 import os
 import unittest
 
@@ -106,6 +107,32 @@
 CERT_PATH   = f'{swanctl_dir}/x509/'
 CA_PATH     = f'{swanctl_dir}/x509ca/'
 
+
+def _encode_to_base64(input_string):
+    """
+    Encodes a given string to its base64 representation.
+
+    Args:
+        input_string (str): The string to be encoded.
+
+    Returns:
+        str: The base64-encoded version of the input string.
+
+    Example:
+        input_string = "Hello, World!"
+        encoded_string = _encode_to_base64(input_string)
+        print(encoded_string)  # Output: SGVsbG8sIFdvcmxkIQ==
+    """
+    # Convert the string to bytes
+    byte_string = input_string.encode('utf-8')
+
+    # Encode the byte string to base64
+    encoded_string = base64.b64encode(byte_string)
+
+    # Decode the base64 bytes back to a string
+    return encoded_string.decode('utf-8')
+
+
 class TestVPNIPsec(VyOSUnitTestSHIM.TestCase):
     skip_process_check = False
 
@@ -495,6 +522,7 @@ def test_flex_vpn_vips(self):
         local_id = 'vyos-r1'
         remote_id = 'vyos-r2'
         peer_base_path = base_path + ['site-to-site', 'peer', connection_name]
+        secret_base64 = _encode_to_base64(secret)
 
         self.cli_set(tunnel_path + ['tun1', 'encapsulation', 'gre'])
         self.cli_set(tunnel_path + ['tun1', 'source-address', local_address])
@@ -509,7 +537,8 @@ def test_flex_vpn_vips(self):
         self.cli_set(base_path + ['authentication', 'psk', connection_name, 'id', remote_id])
         self.cli_set(base_path + ['authentication', 'psk', connection_name, 'id', local_address])
         self.cli_set(base_path + ['authentication', 'psk', connection_name, 'id', peer_ip])
-        self.cli_set(base_path + ['authentication', 'psk', connection_name, 'secret', secret])
+        self.cli_set(base_path + ['authentication', 'psk', connection_name, 'secret', secret_base64])
+        self.cli_set(base_path + ['authentication', 'psk', connection_name, 'secret-type', 'base64'])
 
         self.cli_set(peer_base_path + ['authentication', 'local-id', local_id])
         self.cli_set(peer_base_path + ['authentication', 'mode', 'pre-shared-secret'])
@@ -546,7 +575,7 @@ def test_flex_vpn_vips(self):
             f'id-{regex_uuid4} = "{remote_id}"',
             f'id-{regex_uuid4} = "{peer_ip}"',
             f'id-{regex_uuid4} = "{local_address}"',
-            f'secret = "{secret}"',
+            f'secret = 0s{secret_base64}',
         ]
 
         for line in swanctl_secrets_lines: