service https: T1585: add support for letsencrypt certificates

5 files changed, 230 insertions, 8 deletions

diff --git a/debian/control b/debian/control
index 9df421977..bca066aff 100644
--- a/debian/control
+++ b/debian/control
@@ -81,6 +81,7 @@ Depends: python3,
   crda,
   wireless-regdb,
   pmacct (>= 1.6.0),
+  python3-certbot-nginx,
   ${shlibs:Depends},
   ${misc:Depends}
 Description: VyOS configuration scripts and data
diff --git a/interface-definitions/https.xml.in b/interface-definitions/https.xml.in
index fd4395ce9..4f940f7f6 100644
--- a/interface-definitions/https.xml.in
+++ b/interface-definitions/https.xml.in
@@ -124,6 +124,24 @@
                   </leafNode>
                 </children>
               </node>
+              <node name="certbot" owner="${vyos_conf_scripts_dir}/le_cert.py">
+                <properties>
+                  <help>Request or apply a letsencrypt certificate for domain-name</help>
+                </properties>
+                <children>
+                  <leafNode name="domain-name">
+                    <properties>
+                      <help>Domain name(s) for which to obtain certificate</help>
+                      <multi/>
+                    </properties>
+                  </leafNode>
+                  <leafNode name="email">
+                      <properties>
+                          <help>Email address to associate with certificate</help>
+                      </properties>
+                  </leafNode>
+                </children>
+              </node>
             </children>
           </node>
         </children>
diff --git a/python/vyos/certbot_util.py b/python/vyos/certbot_util.py
new file mode 100644
index 000000000..df42d4780
--- /dev/null
+++ b/python/vyos/certbot_util.py
@@ -0,0 +1,58 @@
+# certbot_util -- adaptation of certbot_nginx name matching functions for VyOS
+# https://github.com/certbot/certbot/blob/master/LICENSE.txt
+
+from certbot_nginx import parser
+
+NAME_RANK = 0
+START_WILDCARD_RANK = 1
+END_WILDCARD_RANK = 2
+REGEX_RANK = 3
+
+def _rank_matches_by_name(server_block_list, target_name):
+    """Returns a ranked list of server_blocks that match target_name.
+    Adapted from the function of the same name in
+    certbot_nginx.NginxConfigurator
+    """
+    matches = []
+    for server_block in server_block_list:
+        name_type, name = parser.get_best_match(target_name,
+                                                server_block['name'])
+        if name_type == 'exact':
+            matches.append({'vhost': server_block,
+                            'name': name,
+                            'rank': NAME_RANK})
+        elif name_type == 'wildcard_start':
+            matches.append({'vhost': server_block,
+                            'name': name,
+                            'rank': START_WILDCARD_RANK})
+        elif name_type == 'wildcard_end':
+            matches.append({'vhost': server_block,
+                            'name': name,
+                            'rank': END_WILDCARD_RANK})
+        elif name_type == 'regex':
+            matches.append({'vhost': server_block,
+                            'name': name,
+                            'rank': REGEX_RANK})
+
+    return sorted(matches, key=lambda x: x['rank'])
+
+def _select_best_name_match(matches):
+    """Returns the best name match of a ranked list of server_blocks.
+    Adapted from the function of the same name in
+    certbot_nginx.NginxConfigurator
+    """
+    if not matches:
+        return None
+    elif matches[0]['rank'] in [START_WILDCARD_RANK, END_WILDCARD_RANK]:
+        rank = matches[0]['rank']
+        wildcards = [x for x in matches if x['rank'] == rank]
+        return max(wildcards, key=lambda x: len(x['name']))['vhost']
+    else:
+        return matches[0]['vhost']
+
+def choose_server_block(server_block_list, target_name):
+    matches = _rank_matches_by_name(server_block_list, target_name)
+    server_blocks = [x for x in [_select_best_name_match(matches)]
+                     if x is not None]
+    return server_blocks
+
diff --git a/src/conf_mode/https.py b/src/conf_mode/https.py
index fbd351e45..2b492be26 100755
--- a/src/conf_mode/https.py
+++ b/src/conf_mode/https.py
@@ -22,6 +22,7 @@ import os
 import jinja2
 
 import vyos.defaults
+import vyos.certbot_util
 from vyos.config import Config
 from vyos import ConfigError
 
@@ -56,7 +57,12 @@ server {
         server_name {{ name }};
 {% endfor %}
 
-{% if server.vyos_cert %}
+{% if server.certbot %}
+        ssl_certificate /etc/letsencrypt/live/{{ server.certbot_dir }}/fullchain.pem;
+        ssl_certificate_key /etc/letsencrypt/live/{{ server.certbot_dir }}/privkey.pem;
+        include /etc/letsencrypt/options-ssl-nginx.conf;
+        ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;
+{% elif server.vyos_cert %}
         include {{ server.vyos_cert.conf }};
 {% else %}
         #
@@ -91,9 +97,9 @@ server {
 default_server_block = {
     'address'   : '*',
     'name'      : ['_'],
-    # api       :
-    # vyos_cert :
-    # le_cert   :
+    'api'       : {},
+    'vyos_cert' : {},
+    'certbot'   : False
 }
 
 def get_config():
@@ -121,13 +127,27 @@ def get_config():
         server_block_list.append(default_server_block)
 
     vyos_cert_data = {}
-    if conf.exists('certificates'):
-        if conf.exists('certificates system-generated-certificate'):
-            vyos_cert_data = vyos.defaults.vyos_cert_data
+    if conf.exists('certificates system-generated-certificate'):
+        vyos_cert_data = vyos.defaults.vyos_cert_data
     if vyos_cert_data:
         for block in server_block_list:
             block['vyos_cert'] = vyos_cert_data
 
+    certbot = False
+    certbot_domains = []
+    if conf.exists('certificates certbot domain-name'):
+        certbot_domains = conf.return_values('certificates certbot domain-name')
+    if certbot_domains:
+        certbot = True
+        for domain in certbot_domains:
+            sub_list = vyos.certbot_util.choose_server_block(server_block_list,
+                                                             domain)
+            if sub_list:
+                for sb in sub_list:
+                    sb['certbot'] = True
+                    # certbot organizes certificates by first domain
+                    sb['certbot_dir'] = certbot_domains[0]
+
     api_data = {}
     if conf.exists('api'):
         api_data = vyos.defaults.api_data
@@ -138,10 +158,16 @@ def get_config():
         for block in server_block_list:
             block['api'] = api_data
 
-    https = {'server_block_list' : server_block_list}
+    https = {'server_block_list' : server_block_list, 'certbot': certbot}
     return https
 
 def verify(https):
+    if https['certbot']:
+        for sb in https['server_block_list']:
+            if sb['certbot']:
+                return None
+        raise ConfigError("At least one 'listen-address x.x.x.x server-name' "
+                          "matching the 'certbot domain-name' is required.")
     return None
 
 def generate(https):
diff --git a/src/conf_mode/le_cert.py b/src/conf_mode/le_cert.py
new file mode 100755
index 000000000..c657098e1
--- /dev/null
+++ b/src/conf_mode/le_cert.py
@@ -0,0 +1,119 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2019 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
+# published by the Free Software Foundation.
+#
+# This program 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 General Public License for more details.
+#
+# 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 sys
+import os
+import subprocess
+
+import vyos.defaults
+from vyos.config import Config
+from vyos import ConfigError
+
+vyos_conf_scripts_dir = vyos.defaults.directories['conf_mode']
+
+dependencies = [
+    'https.py',
+]
+
+def request_certbot(cert):
+    email = cert.get('email')
+    if email is not None:
+        email_flag = '-m {0}'.format(email)
+    else:
+        email_flag = ''
+
+    domains = cert.get('domains')
+    if domains is not None:
+        domain_flag = '-d ' + ' -d '.join(domains)
+    else:
+        domain_flag = ''
+
+    certbot_cmd = 'certbot certonly -n --nginx --agree-tos --no-eff-email --expand {0} {1}'.format(email_flag, domain_flag)
+
+    completed = subprocess.run(certbot_cmd, shell=True)
+
+    return completed.returncode
+
+def get_config():
+    conf = Config()
+    if not conf.exists('service https certificates certbot'):
+        return None
+    else:
+        conf.set_level('service https certificates certbot')
+
+    cert = {}
+
+    if conf.exists('domain-name'):
+        cert['domains'] = conf.return_values('domain-name')
+
+    if conf.exists('email'):
+        cert['email'] = conf.return_value('email')
+
+    return cert
+
+def verify(cert):
+    if cert is None:
+        return None
+
+    if 'domains' not in cert:
+        raise ConfigError("At least one domain name is required to"
+                          " request a letsencrypt certificate.")
+
+    if 'email' not in cert:
+        raise ConfigError("An email address is required to request"
+                          " a letsencrypt certificate.")
+
+def generate(cert):
+    if cert is None:
+        return None
+
+    # certbot will attempt to reload nginx, even with 'certonly';
+    # start nginx if not active
+    ret = os.system('systemctl is-active --quiet nginx.ervice')
+    if ret:
+        os.system('sudo systemctl start nginx.service')
+
+    ret = request_certbot(cert)
+    if ret:
+        raise ConfigError("The certbot request failed for the"
+                          " specified domains.")
+
+def apply(cert):
+    if cert is not None:
+        os.system('sudo systemctl restart certbot.timer')
+    else:
+        os.system('sudo systemctl stop certbot.timer')
+        return None
+
+    for dep in dependencies:
+        cmd = '{0}/{1}'.format(vyos_conf_scripts_dir, dep)
+        try:
+            subprocess.check_call(cmd, shell=True)
+        except subprocess.CalledProcessError as err:
+            raise ConfigError(str(err))
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        sys.exit(1)
+