configverify: T6198: add common helper for PKI certificate validation

The next evolutional step after adding get_config_dict(..., with_pki=True) is
to add a common verification function for the recurring task of validating SSL
certificate existance in e.g. EAPoL, OpenConnect, SSTP or HTTPS.

(cherry picked from commit 3b758d870449e92fece9e29c791b950b332e6e65)

7 files changed, 249 insertions, 203 deletions

diff --git a/python/vyos/configverify.py b/python/vyos/configverify.py
index 6508ccdd9..2a5452e7b 100644
--- a/python/vyos/configverify.py
+++ b/python/vyos/configverify.py
@@ -162,43 +162,6 @@ def verify_tunnel(config):
         if 'source_address' in config and is_ipv6(config['source_address']):
             raise ConfigError('Can not use local IPv6 address is for mGRE tunnels')
 
-def verify_eapol(config):
-    """
-    Common helper function used by interface implementations to perform
-    recurring validation of EAPoL configuration.
-    """
-    if 'eapol' in config:
-        if 'certificate' not in config['eapol']:
-            raise ConfigError('Certificate must be specified when using EAPoL!')
-
-        if 'pki' not in config or 'certificate' not in config['pki']:
-            raise ConfigError('Invalid certificate specified for EAPoL')
-
-        cert_name = config['eapol']['certificate']
-        if cert_name not in config['pki']['certificate']:
-            raise ConfigError('Invalid certificate specified for EAPoL')
-
-        cert = config['pki']['certificate'][cert_name]
-
-        if 'certificate' not in cert or 'private' not in cert or 'key' not in cert['private']:
-            raise ConfigError('Invalid certificate/private key specified for EAPoL')
-
-        if 'password_protected' in cert['private']:
-            raise ConfigError('Encrypted private key cannot be used for EAPoL')
-
-        if 'ca_certificate' in config['eapol']:
-            if 'ca' not in config['pki']:
-                raise ConfigError('Invalid CA certificate specified for EAPoL')
-
-            for ca_cert_name in config['eapol']['ca_certificate']:
-                if ca_cert_name not in config['pki']['ca']:
-                    raise ConfigError('Invalid CA certificate specified for EAPoL')
-
-                ca_cert = config['pki']['ca'][ca_cert_name]
-
-                if 'certificate' not in ca_cert:
-                    raise ConfigError('Invalid CA certificate specified for EAPoL')
-
 def verify_mirror_redirect(config):
     """
     Common helper function used by interface implementations to perform
@@ -487,3 +450,69 @@ def verify_access_list(access_list, config, version=''):
     # Check if the specified ACL exists, if not error out
     if dict_search(f'policy.access-list{version}.{access_list}', config) == None:
         raise ConfigError(f'Specified access-list{version} "{access_list}" does not exist!')
+
+def verify_pki_certificate(config: dict, cert_name: str, no_password_protected: bool=False):
+    """
+    Common helper function user by PKI consumers to perform recurring
+    validation functions for PEM based certificates
+    """
+    if 'pki' not in config:
+        raise ConfigError('PKI is not configured!')
+
+    if 'certificate' not in config['pki']:
+        raise ConfigError('PKI does not contain any certificates!')
+
+    if cert_name not in config['pki']['certificate']:
+        raise ConfigError(f'Certificate "{cert_name}" not found in configuration!')
+
+    pki_cert = config['pki']['certificate'][cert_name]
+    if 'certificate' not in pki_cert:
+        raise ConfigError(f'PEM certificate for "{cert_name}" missing in configuration!')
+
+    if 'private' not in pki_cert or 'key' not in pki_cert['private']:
+        raise ConfigError(f'PEM private key for "{cert_name}" missing in configuration!')
+
+    if no_password_protected and 'password_protected' in pki_cert['private']:
+        raise ConfigError('Password protected PEM private key is not supported!')
+
+def verify_pki_ca_certificate(config: dict, ca_name: str):
+    """
+    Common helper function user by PKI consumers to perform recurring
+    validation functions for PEM based CA certificates
+    """
+    if 'pki' not in config:
+        raise ConfigError('PKI is not configured!')
+
+    if 'ca' not in config['pki']:
+        raise ConfigError('PKI does not contain any CA certificates!')
+
+    if ca_name not in config['pki']['ca']:
+        raise ConfigError(f'CA Certificate "{ca_name}" not found in configuration!')
+
+    pki_cert = config['pki']['ca'][ca_name]
+    if 'certificate' not in pki_cert:
+        raise ConfigError(f'PEM CA certificate for "{cert_name}" missing in configuration!')
+
+def verify_pki_dh_parameters(config: dict, dh_name: str, min_key_size: int=0):
+    """
+    Common helper function user by PKI consumers to perform recurring
+    validation functions on DH parameters
+    """
+    from vyos.pki import load_dh_parameters
+
+    if 'pki' not in config:
+        raise ConfigError('PKI is not configured!')
+
+    if 'dh' not in config['pki']:
+        raise ConfigError('PKI does not contain any DH parameters!')
+
+    if dh_name not in config['pki']['dh']:
+        raise ConfigError(f'DH parameter "{dh_name}" not found in configuration!')
+
+    if min_key_size:
+        pki_dh = config['pki']['dh'][dh_name]
+        dh_params = load_dh_parameters(pki_dh['parameters'])
+        dh_numbers = dh_params.parameter_numbers()
+        dh_bits = dh_numbers.p.bit_length()
+        if dh_bits < min_key_size:
+            raise ConfigError(f'Minimum DH key-size is {min_key_size} bits!')
diff --git a/smoketest/scripts/cli/test_vpn_openconnect.py b/smoketest/scripts/cli/test_vpn_openconnect.py
index c4502fada..96e858fdb 100755
--- a/smoketest/scripts/cli/test_vpn_openconnect.py
+++ b/smoketest/scripts/cli/test_vpn_openconnect.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2020-2022 VyOS maintainers and contributors
+# Copyright (C) 2020-2024 VyOS maintainers and contributors
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 or later as
@@ -18,6 +18,7 @@ import unittest
 
 from base_vyostest_shim import VyOSUnitTestSHIM
 
+from vyos.configsession import ConfigSessionError
 from vyos.template import ip_from_cidr
 from vyos.utils.process import process_named_running
 from vyos.utils.file import read_file
@@ -27,25 +28,110 @@ base_path = ['vpn', 'openconnect']
 
 pki_path = ['pki']
 
+cert_name = 'OCServ'
 cert_data = """
-MIICFDCCAbugAwIBAgIUfMbIsB/ozMXijYgUYG80T1ry+mcwCgYIKoZIzj0EAwIw
-WTELMAkGA1UEBhMCR0IxEzARBgNVBAgMClNvbWUtU3RhdGUxEjAQBgNVBAcMCVNv
-bWUtQ2l0eTENMAsGA1UECgwEVnlPUzESMBAGA1UEAwwJVnlPUyBUZXN0MB4XDTIx
-MDcyMDEyNDUxMloXDTI2MDcxOTEyNDUxMlowWTELMAkGA1UEBhMCR0IxEzARBgNV
-BAgMClNvbWUtU3RhdGUxEjAQBgNVBAcMCVNvbWUtQ2l0eTENMAsGA1UECgwEVnlP
-UzESMBAGA1UEAwwJVnlPUyBUZXN0MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE
-01HrLcNttqq4/PtoMua8rMWEkOdBu7vP94xzDO7A8C92ls1v86eePy4QllKCzIw3
-QxBIoCuH2peGRfWgPRdFsKNhMF8wDwYDVR0TAQH/BAUwAwEB/zAOBgNVHQ8BAf8E
-BAMCAYYwHQYDVR0lBBYwFAYIKwYBBQUHAwIGCCsGAQUFBwMBMB0GA1UdDgQWBBSu
-+JnU5ZC4mkuEpqg2+Mk4K79oeDAKBggqhkjOPQQDAgNHADBEAiBEFdzQ/Bc3Lftz
-ngrY605UhA6UprHhAogKgROv7iR4QgIgEFUxTtW3xXJcnUPWhhUFhyZoqfn8dE93
-+dm/LDnp7C0=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 """
 
-key_data = """
-MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQgPLpD0Ohhoq0g4nhx
-2KMIuze7ucKUt/lBEB2wc03IxXyhRANCAATTUestw222qrj8+2gy5rysxYSQ50G7
-u8/3jHMM7sDwL3aWzW/zp54/LhCWUoLMjDdDEEigK4fal4ZF9aA9F0Ww
+cert_key_data = """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+"""
+
+ca_name = 'VyOS-CA'
+ca_data = """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+"""
+
+ca_key_data = """
+ MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQCg7Mjl6+rs8Bd
+ kjqgl2QDuHfrH2mTDCeB7WuNTnIz0BPDtlmwIdqhU7LdCB/zUSABAa6LBe/Z/bK
+ WCRKyq8fU2/4uWECe975IMXOfFdYT6KA78DROvOi32JZmln0LAXV+538eb+g19x
+ NtoBhPO8igiNevfkV+nJehRK/41ATj+assTOv87vaSX7WqyaP/ZqkIdQD9Kc3cq
+ B4JsYjkWcniHL9yk4oY3cjKK8PJ1pi4FqgFHt2hA+Ic+NvbAhc47K9otP8FM4jk
+ Sii3MZfHA6Czb43BtbR+YEiWPzBhzE2bCuIgeRUumMF1Z+CAT6U7Cpx3XPh+Ac2
+ RnDa8wKeQ1eqE1AgMBAAECggEAEDDaoqVqmMWsONoQiWRMr2h1RZvPxP7OpuKVW
+ iF3XgrMOb9HZc+Ybpj1dC+NDMekvNaHhMuF2Lqz6UgjDjzzVMH/x4yfDwFWUqeb
+ SxbglvGmVk4zg48JNkmArLT6GJQccD1XXjZZmqSOhagM4KalCpIdxfvgoZbTCa2
+ xMSCLHS+1HCDcmpCoeXM6ZBPTn0NbjRDAqIzCwcq2veG7RSz040obk8h7nrdv7j
+ hxRGmtPmPFzKgGLNn6GnL7AwYVMiidjj/ntvM4B1OMs9MwUYbtpg98TWcWyu+ZR
+ akUrnVf9z2aIHCKyuJvke/PNqMgw+L8KV4/478XxWhXfl7K1F3nMQKBgQDRBUDY
+ NFH0wC4MMWsA+RGwyz7RlzACChDJCMtA/agbW06gUoE9UYf8KtLQQQYljlLJHxH
+ GD72QnuM+sowGGXnbD4BabA9TQiQUG5c6boznTy1uU1gt8T0Zl0mmC7vIMoMBVd
+ 5bb0qrZvuR123kDGYn6crug9uvMIYSSlhGmBGTJQKBgQDFGC3vfkCyXzLoYy+RI
+ s/rXgyBF1PUYQtyDgL0N811L0H7a8JhFnt4FvodUbxv2ob+1kIc9e3yXT6FsGyO
+ 7IDOnqgeQKy74bYqVPZZuf1FOFb9fuxf00pn1FmhAF4OuSWkhVhrKkyrZwdD8Ar
+ jLK253J94dogjdKAYfN1csaOA0QKBgD0zUZI8d4a3QoRVb+RACTr/t6v8nZTrR5
+ DlX0XvP2qLKJFutuKyXaOrEkDh2R/j9T9oNncMos+WhikUdEVQ7koC1u0i2LXjF
+ tdAYN4+Akmz+DRmeNoy2VYF4w2YP+pVR+B7OPkCtBVNuPkx3743Fy42mTGPMCKy
+ jX8Lf59j5Tl1AoGBAI3sk2dZqozHMIlWovIH92CtIKP0gFD2cJ94p3fklvZDSWg
+ aeKYg4lffc8uZB/AjlAH9ly3ziZx0uIjcOc/RTg96/+SI/dls9xgUhjCmVVJ692
+ ki9GMsau/JYaEl+pTvjcOiocDJfNwQHJM3Tx+3FII59DtyXyXo3T/E6kHNSMeBA
+ oGAR9M48DTspv9OH1S7X6yR6MtMY5ltsBmB3gPhQFxiDKBvARkIkAPqObQ9TG/V
+ uOz2Purq0Oz7SHsY2jiFDd2KEGo6JfG61NDdIhiQC99ztSgt7NtvSCnX22SfVDW
+ oFxSK+tek7tvDVXAXCNy4ZESMEUGJ6NDHImb80aF+xZ3wYKw=
 """
 
 PROCESS_NAME = 'ocserv-main'
@@ -67,9 +153,10 @@ class TestVPNOpenConnect(VyOSUnitTestSHIM.TestCase):
 
         cls.cli_set(cls, ['interfaces', 'dummy', listen_if, 'address', listen_address])
 
-        cls.cli_set(cls, pki_path + ['ca', 'openconnect', 'certificate', cert_data.replace('\n','')])
-        cls.cli_set(cls, pki_path + ['certificate', 'openconnect', 'certificate', cert_data.replace('\n','')])
-        cls.cli_set(cls, pki_path + ['certificate', 'openconnect', 'private', 'key', key_data.replace('\n','')])
+        cls.cli_set(cls, pki_path + ['ca', cert_name, 'certificate', ca_data.replace('\n','')])
+        cls.cli_set(cls, pki_path + ['ca', cert_name, 'private', 'key', ca_key_data.replace('\n','')])
+        cls.cli_set(cls, pki_path + ['certificate', cert_name, 'certificate', cert_data.replace('\n','')])
+        cls.cli_set(cls, pki_path + ['certificate', cert_name, 'private', 'key', cert_key_data.replace('\n','')])
 
     @classmethod
     def tearDownClass(cls):
@@ -108,8 +195,12 @@ class TestVPNOpenConnect(VyOSUnitTestSHIM.TestCase):
         for domain in split_dns:
             self.cli_set(base_path + ['network-settings', 'split-dns', domain])
 
-        self.cli_set(base_path + ['ssl', 'ca-certificate', 'openconnect'])
-        self.cli_set(base_path + ['ssl', 'certificate', 'openconnect'])
+        # SSL certificates are mandatory
+        with self.assertRaises(ConfigSessionError):
+            self.cli_commit()
+
+        self.cli_set(base_path + ['ssl', 'ca-certificate', cert_name])
+        self.cli_set(base_path + ['ssl', 'certificate', cert_name])
 
         listen_ip_no_cidr = ip_from_cidr(listen_address)
         self.cli_set(base_path + ['listen-address', listen_ip_no_cidr])
diff --git a/src/conf_mode/interfaces_ethernet.py b/src/conf_mode/interfaces_ethernet.py
index 2c0f846c3..504d48f89 100755
--- a/src/conf_mode/interfaces_ethernet.py
+++ b/src/conf_mode/interfaces_ethernet.py
@@ -15,7 +15,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
-import pprint
 
 from glob import glob
 from sys import exit
@@ -26,7 +25,6 @@ from vyos.configdict import get_interface_dict
 from vyos.configdict import is_node_changed
 from vyos.configverify import verify_address
 from vyos.configverify import verify_dhcpv6
-from vyos.configverify import verify_eapol
 from vyos.configverify import verify_interface_exists
 from vyos.configverify import verify_mirror_redirect
 from vyos.configverify import verify_mtu
@@ -34,6 +32,8 @@ from vyos.configverify import verify_mtu_ipv6
 from vyos.configverify import verify_vlan_config
 from vyos.configverify import verify_vrf
 from vyos.configverify import verify_bond_bridge_member
+from vyos.configverify import verify_pki_certificate
+from vyos.configverify import verify_pki_ca_certificate
 from vyos.ethtool import Ethtool
 from vyos.ifconfig import EthernetIf
 from vyos.ifconfig import BondIf
@@ -263,6 +263,22 @@ def verify_allowedbond_changes(ethernet: dict):
                               f' on interface "{ethernet["ifname"]}".' \
                               f' Interface is a bond member')
 
+def verify_eapol(ethernet: dict):
+    """
+    Common helper function used by interface implementations to perform
+    recurring validation of EAPoL configuration.
+    """
+    if 'eapol' not in ethernet:
+        return
+
+    if 'certificate' not in ethernet['eapol']:
+        raise ConfigError('Certificate must be specified when using EAPoL!')
+
+    verify_pki_certificate(ethernet, ethernet['eapol']['certificate'], no_password_protected=True)
+
+    if 'ca_certificate' in ethernet['eapol']:
+        for ca_cert in ethernet['eapol']['ca_certificate']:
+            verify_pki_ca_certificate(ethernet, ca_cert)
 
 def verify(ethernet):
     if 'deleted' in ethernet:
diff --git a/src/conf_mode/load-balancing_reverse-proxy.py b/src/conf_mode/load-balancing_reverse-proxy.py
index 2a0acd84a..694a4e1ea 100755
--- a/src/conf_mode/load-balancing_reverse-proxy.py
+++ b/src/conf_mode/load-balancing_reverse-proxy.py
@@ -20,6 +20,9 @@ from sys import exit
 from shutil import rmtree
 
 from vyos.config import Config
+from vyos.configverify import verify_pki_certificate
+from vyos.configverify import verify_pki_ca_certificate
+from vyos.utils.dict import dict_search
 from vyos.utils.process import call
 from vyos.utils.network import check_port_availability
 from vyos.utils.network import is_listen_port_bind_service
@@ -33,8 +36,7 @@ airbag.enable()
 load_balancing_dir = '/run/haproxy'
 load_balancing_conf_file = f'{load_balancing_dir}/haproxy.cfg'
 systemd_service = 'haproxy.service'
-systemd_override = r'/run/systemd/system/haproxy.service.d/10-override.conf'
-
+systemd_override = '/run/systemd/system/haproxy.service.d/10-override.conf'
 
 def get_config(config=None):
     if config:
@@ -54,30 +56,6 @@ def get_config(config=None):
 
     return lb
 
-
-def _verify_cert(lb: dict, config: dict) -> None:
-    if 'ca_certificate' in config['ssl']:
-        ca_name = config['ssl']['ca_certificate']
-        pki_ca = lb['pki'].get('ca')
-        if pki_ca is None:
-            raise ConfigError(f'CA certificates does not exist in PKI')
-        else:
-            ca = pki_ca.get(ca_name)
-            if ca is None:
-                raise ConfigError(f'CA certificate "{ca_name}" does not exist')
-
-    elif 'certificate' in config['ssl']:
-        cert_names = config['ssl']['certificate']
-        pki_certs = lb['pki'].get('certificate')
-        if pki_certs is None:
-            raise ConfigError(f'Certificates does not exist in PKI')
-
-        for cert_name in cert_names:
-            pki_cert = pki_certs.get(cert_name)
-            if pki_cert is None:
-                raise ConfigError(f'Certificate "{cert_name}" does not exist')
-
-
 def verify(lb):
     if not lb:
         return None
@@ -107,12 +85,12 @@ def verify(lb):
                 raise ConfigError(f'Cannot use both "send-proxy" and "send-proxy-v2" for server "{bk_server}"')
 
     for front, front_config in lb['service'].items():
-        if 'ssl' in front_config:
-            _verify_cert(lb, front_config)
+        for cert in dict_search('ssl.certificate', front_config) or []:
+            verify_pki_certificate(lb, cert)
 
     for back, back_config in lb['backend'].items():
-        if 'ssl' in back_config:
-            _verify_cert(lb, back_config)
+        tmp = dict_search('ssl.ca_certificate', front_config)
+        if tmp: verify_pki_ca_certificate(lb, tmp)
 
 
 def generate(lb):
diff --git a/src/conf_mode/service_https.py b/src/conf_mode/service_https.py
index 46efc3c93..9e58b4c72 100755
--- a/src/conf_mode/service_https.py
+++ b/src/conf_mode/service_https.py
@@ -24,13 +24,14 @@ from time import sleep
 from vyos.base import Warning
 from vyos.config import Config
 from vyos.config import config_dict_merge
-from vyos.configdiff import get_config_diff
 from vyos.configverify import verify_vrf
+from vyos.configverify import verify_pki_certificate
+from vyos.configverify import verify_pki_ca_certificate
+from vyos.configverify import verify_pki_dh_parameters
 from vyos.defaults import api_config_state
 from vyos.pki import wrap_certificate
 from vyos.pki import wrap_private_key
 from vyos.pki import wrap_dh_parameters
-from vyos.pki import load_dh_parameters
 from vyos.template import render
 from vyos.utils.dict import dict_search
 from vyos.utils.process import call
@@ -84,33 +85,14 @@ def verify(https):
     if https is None:
         return None
 
-    if 'certificates' in https and 'certificate' in https['certificates']:
-        cert_name = https['certificates']['certificate']
-        if 'pki' not in https:
-            raise ConfigError('PKI is not configured!')
-
-        if cert_name not in https['pki']['certificate']:
-            raise ConfigError('Invalid certificate in configuration!')
+    if dict_search('certificates.certificate', https) != None:
+        verify_pki_certificate(https, https['certificates']['certificate'])
 
-        pki_cert = https['pki']['certificate'][cert_name]
-
-        if 'certificate' not in pki_cert:
-            raise ConfigError('Missing certificate in configuration!')
+        tmp = dict_search('certificates.ca_certificate', https)
+        if tmp != None: verify_pki_ca_certificate(https, tmp)
 
-        if 'private' not in pki_cert or 'key' not in pki_cert['private']:
-            raise ConfigError('Missing certificate private key in configuration!')
-
-        if 'dh_params' in https['certificates']:
-            dh_name = https['certificates']['dh_params']
-            if dh_name not in https['pki']['dh']:
-                raise ConfigError('Invalid DH parameter in configuration!')
-
-            pki_dh = https['pki']['dh'][dh_name]
-            dh_params = load_dh_parameters(pki_dh['parameters'])
-            dh_numbers = dh_params.parameter_numbers()
-            dh_bits = dh_numbers.p.bit_length()
-            if dh_bits < 2048:
-                raise ConfigError(f'Minimum DH key-size is 2048 bits')
+        tmp = dict_search('certificates.dh_params', https)
+        if tmp != None: verify_pki_dh_parameters(https, tmp, 2048)
 
     else:
         Warning('No certificate specified, using build-in self-signed certificates. '\
@@ -214,7 +196,8 @@ def apply(https):
     https_service_name = 'nginx.service'
 
     if https is None:
-        call(f'systemctl stop {http_api_service_name}')
+        if is_systemd_service_active(http_api_service_name):
+            call(f'systemctl stop {http_api_service_name}')
         call(f'systemctl stop {https_service_name}')
         return
 
diff --git a/src/conf_mode/vpn_openconnect.py b/src/conf_mode/vpn_openconnect.py
index 08e4fc6db..8159fedea 100755
--- a/src/conf_mode/vpn_openconnect.py
+++ b/src/conf_mode/vpn_openconnect.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2018-2023 VyOS maintainers and contributors
+# Copyright (C) 2018-2024 VyOS maintainers and contributors
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 or later as
@@ -19,6 +19,8 @@ from sys import exit
 
 from vyos.base import Warning
 from vyos.config import Config
+from vyos.configverify import verify_pki_certificate
+from vyos.configverify import verify_pki_ca_certificate
 from vyos.pki import wrap_certificate
 from vyos.pki import wrap_private_key
 from vyos.template import render
@@ -75,7 +77,7 @@ def verify(ocserv):
     if "accounting" in ocserv:
         if "mode" in ocserv["accounting"] and "radius" in ocserv["accounting"]["mode"]:
             if not origin["accounting"]['radius']['server']:
-                raise ConfigError('Openconnect accounting mode radius requires at least one RADIUS server')
+                raise ConfigError('OpenConnect accounting mode radius requires at least one RADIUS server')
             if "authentication" not in ocserv or "mode" not in ocserv["authentication"]:
                 raise ConfigError('Accounting depends on OpenConnect authentication configuration')
             elif "radius" not in ocserv["authentication"]["mode"]:
@@ -89,12 +91,12 @@ def verify(ocserv):
                     raise ConfigError('OpenConnect authentication modes are mutually-exclusive, remove either local or radius from your configuration')
             if "radius" in ocserv["authentication"]["mode"]:
                 if not ocserv["authentication"]['radius']['server']:
-                    raise ConfigError('Openconnect authentication mode radius requires at least one RADIUS server')
+                    raise ConfigError('OpenConnect authentication mode radius requires at least one RADIUS server')
             if "local" in ocserv["authentication"]["mode"]:
                 if not ocserv.get("authentication", {}).get("local_users"):
-                    raise ConfigError('openconnect mode local required at least one user')
+                    raise ConfigError('OpenConnect mode local required at least one user')
                 if not ocserv["authentication"]["local_users"]["username"]:
-                    raise ConfigError('openconnect mode local required at least one user')
+                    raise ConfigError('OpenConnect mode local required at least one user')
                 else:
                     # For OTP mode: verify that each local user has an OTP key
                     if "otp" in ocserv["authentication"]["mode"]["local"]:
@@ -127,40 +129,20 @@ def verify(ocserv):
                     if 'default_config' not in ocserv["authentication"]["identity_based_config"]:
                         raise ConfigError('OpenConnect identity-based-config enabled but default-config not set')
         else:
-            raise ConfigError('openconnect authentication mode required')
+            raise ConfigError('OpenConnect authentication mode required')
     else:
-        raise ConfigError('openconnect authentication credentials required')
+        raise ConfigError('OpenConnect authentication credentials required')
 
     # Check ssl
     if 'ssl' not in ocserv:
-        raise ConfigError('openconnect ssl required')
+        raise ConfigError('SSL missing on OpenConnect config!')
 
-    if not ocserv['pki'] or 'certificate' not in ocserv['pki']:
-        raise ConfigError('PKI not configured')
+    if 'certificate' not in ocserv['ssl']:
+        raise ConfigError('SSL certificate missing on OpenConnect config!')
+    verify_pki_certificate(ocserv, ocserv['ssl']['certificate'])
 
-    ssl = ocserv['ssl']
-    if 'certificate' not in ssl:
-        raise ConfigError('openconnect ssl certificate required')
-
-    cert_name = ssl['certificate']
-
-    if cert_name not in ocserv['pki']['certificate']:
-        raise ConfigError('Invalid openconnect ssl certificate')
-
-    cert = ocserv['pki']['certificate'][cert_name]
-
-    if 'certificate' not in cert:
-        raise ConfigError('Missing certificate in PKI')
-
-    if 'private' not in cert or 'key' not in cert['private']:
-        raise ConfigError('Missing private key in PKI')
-
-    if 'ca_certificate' in ssl:
-        if 'ca' not in ocserv['pki']:
-            raise ConfigError('PKI not configured')
-
-        if ssl['ca_certificate'] not in ocserv['pki']['ca']:
-            raise ConfigError('Invalid openconnect ssl CA certificate')
+    if 'ca_certificate' in ocserv['ssl']:
+        verify_pki_ca_certificate(ocserv, ocserv['ssl']['ca_certificate'])
 
     # Check network settings
     if "network_settings" in ocserv:
@@ -172,7 +154,7 @@ def verify(ocserv):
         else:
             ocserv["network_settings"]["push_route"] = ["default"]
     else:
-        raise ConfigError('openconnect network settings required')
+        raise ConfigError('OpenConnect network settings required!')
 
 def generate(ocserv):
     if not ocserv:
@@ -276,7 +258,7 @@ def apply(ocserv):
                 break
             sleep(0.250)
             if counter > 5:
-                raise ConfigError('openconnect failed to start, check the logs for details')
+                raise ConfigError('OpenConnect failed to start, check the logs for details')
                 break
             counter += 1
 
diff --git a/src/conf_mode/vpn_sstp.py b/src/conf_mode/vpn_sstp.py
index 8661a8aff..7490fd0e0 100755
--- a/src/conf_mode/vpn_sstp.py
+++ b/src/conf_mode/vpn_sstp.py
@@ -20,6 +20,8 @@ from sys import exit
 
 from vyos.config import Config
 from vyos.configdict import get_accel_dict
+from vyos.configverify import verify_pki_certificate
+from vyos.configverify import verify_pki_ca_certificate
 from vyos.pki import wrap_certificate
 from vyos.pki import wrap_private_key
 from vyos.template import render
@@ -46,51 +48,6 @@ cert_key_path = os.path.join(cfg_dir, 'sstp-cert.key')
 ca_cert_file_path = os.path.join(cfg_dir, 'sstp-ca.pem')
 
 
-def verify_certificate(config):
-    #
-    # SSL certificate checks
-    #
-    if not config['pki']:
-        raise ConfigError('PKI is not configured')
-
-    if 'ssl' not in config:
-        raise ConfigError('SSL missing on SSTP config')
-
-    ssl = config['ssl']
-
-    # CA
-    if 'ca_certificate' not in ssl:
-        raise ConfigError('SSL CA certificate missing on SSTP config')
-
-    ca_name = ssl['ca_certificate']
-
-    if ca_name not in config['pki']['ca']:
-        raise ConfigError('Invalid CA certificate on SSTP config')
-
-    if 'certificate' not in config['pki']['ca'][ca_name]:
-        raise ConfigError('Missing certificate data for CA certificate on SSTP config')
-
-    # Certificate
-    if 'certificate' not in ssl:
-        raise ConfigError('SSL certificate missing on SSTP config')
-
-    cert_name = ssl['certificate']
-
-    if cert_name not in config['pki']['certificate']:
-        raise ConfigError('Invalid certificate on SSTP config')
-
-    pki_cert = config['pki']['certificate'][cert_name]
-
-    if 'certificate' not in pki_cert:
-        raise ConfigError('Missing certificate data for certificate on SSTP config')
-
-    if 'private' not in pki_cert or 'key' not in pki_cert['private']:
-        raise ConfigError('Missing private key for certificate on SSTP config')
-
-    if 'password_protected' in pki_cert['private']:
-        raise ConfigError('Encrypted private key is not supported on SSTP config')
-
-
 def get_config(config=None):
     if config:
         conf = config
@@ -124,7 +81,17 @@ def verify(sstp):
     verify_accel_ppp_ip_pool(sstp)
     verify_accel_ppp_name_servers(sstp)
     verify_accel_ppp_wins_servers(sstp)
-    verify_certificate(sstp)
+
+    if 'ssl' not in sstp:
+        raise ConfigError('SSL missing on SSTP config!')
+
+    if 'certificate' not in sstp['ssl']:
+        raise ConfigError('SSL certificate missing on SSTP config!')
+    verify_pki_certificate(sstp, sstp['ssl']['certificate'])
+
+    if 'ca_certificate' not in sstp['ssl']:
+        raise ConfigError('SSL CA certificate missing on SSTP config!')
+    verify_pki_ca_certificate(sstp, sstp['ssl']['ca_certificate'])
 
 
 def generate(sstp):
@@ -154,15 +121,15 @@ def generate(sstp):
 
 
 def apply(sstp):
+    systemd_service = 'accel-ppp@sstp.service'
     if not sstp:
-        call('systemctl stop accel-ppp@sstp.service')
+        call(f'systemctl stop {systemd_service}')
         for file in [sstp_chap_secrets, sstp_conf]:
             if os.path.exists(file):
                 os.unlink(file)
-
         return None
 
-    call('systemctl restart accel-ppp@sstp.service')
+    call(f'systemctl reload-or-restart {systemd_service}')
 
 
 if __name__ == '__main__':