Merge pull request #64 from NitrogenUA/lets-encrypt-dns-01

Implementation of dns-01 challenge support in Confconsole Let's Encrypt plugin.

docs/RelNotes-2.1.0.txt

@@ -0,0 +1,5 @@
+====================
+v2.1.0 Release Notes
+====================
+
+* implemented support for dns-01 challenge in Let's Encrypt plugin.

plugins.d/Lets_Encrypt/dehydrated-wrapper

@@ -1,12 +1,12 @@
 #!/bin/bash -e
 
-# Copyright (c) 2016-2020 TurnKey GNU/Linux - https://www.turnkeylinux.org
+# Copyright (c) 2016-2022 TurnKey GNU/Linux - https://www.turnkeylinux.org
 #
 # dehyrdated-wrapper - A wrapper script for the Dehydrated
 #                      Let's Encrypt client
-# 
+#
 # This file is part of Confconsole.
-# 
+#
 # Confconsole is free software; you can redistribute it and/or modify it
 # under the terms of the GNU Affero General Public License as published by the
 # Free Software Foundation; either version 3 of the License, or (at your
@@ -39,8 +39,10 @@ LICENSE=$(curl $LE_TOS_URL 2>/dev/null | grep termsOfService \
 
 SH_CONFIG=$SHARE/dehydrated-confconsole.config
 SH_HOOK=$SHARE/dehydrated-confconsole.hook.sh
+SH_HOOK_DNS=$SHARE/dehydrated-confconsole.hook-dns.sh
 SH_CRON=$SHARE/dehydrated-confconsole.cron
 SH_DOMAINS=$SHARE/dehydrated-confconsole.domains
+export LEXICON_CONFIG_DIR=$SHARE
 
 export TKL_CERTFILE="/usr/local/share/ca-certificates/cert.crt"
 export TKL_KEYFILE="/etc/ssl/private/cert.key"
@@ -63,7 +65,7 @@ chown -R $HTTP_USR "$(dirname $HTTP_PID)" "$(dirname $LOG)"
 usage() {
 echo "$@"
 cat<<EOF
-Syntax: $APP [--force|-f] [-r|--register] [--log-info|-i] [--help|-h]
+Syntax: $APP [--force|-f] [--register|-r] [--challenge|-c <type>] [--provider|-p <name>] [--log-info|-i] [--help|-h]
 
 TurnKey Linux wrapper script for dehydrated.
 
@@ -82,23 +84,31 @@ Environment variables:
 
 Options:
 
-    --force|-f     - pass force switch to dehydrated
+    --force|-f            - Pass --force switch to dehydrated.
+
+                            This will force dehydrated to update certs
+                            regardless of expiry. The included cron job does
+                            this by default (after checking the expiry of
+                            /etc/ssl/private/cert.pem).
+
+    --register|-r         - Accept Terms of Service (ToS) and register a
+                            Let's Encrypt account. (Note if an LE account
+                            already registered, this option makes no difference
+                            so is safe to always use).
 
-                     This will force dehydrated to update certs regardless of
-                     expiry. The included cron job does this by default (after
-                     checking the expiry of /etc/ssl/private/cert.pem)
+                            Let's Encrypt ToS can currently be found here:
+                            $LICENSE
 
-    --register|-r  - Accept Terms of Service (ToS) and register a Let's Encrypt
-                     account. (Note if an LE account already registered, this
-                     option makes no difference so is safe to always use).
+    --challenge|-c <type> - Instruct dehydrated to use specific challenge type.
 
-                     Let's Encrypt ToS can currently be found here:
-                     $LICENSE
+    --provider|-p <name> -  Specify DNS provider name to use with dns-01
+                            challenge. Refer to lexicon documentation for the
+                            list of supported providers.
 
-    --log-info|-i  - INFO will be logged (default logging is WARNING & FATAL
-                     only)
+    --log-info|-i         - INFO will be logged (default logging is
+                            WARNING & FATAL only).
 
-    --help|-h      - print this information and exit
+    --help|-h             - Print this information and exit.
 
 For more info on advanced usage, please see
 
@@ -209,6 +219,14 @@ while [[ $# -gt 0 ]]; do
     case $arg in
         -f|--force)     args="$args --force";;
         -r|--register)  REGISTER=y;;
+        -c|--challenge) if [[ ! -z $2 && ! $2 =~ ^- ]]; then
+                            CTYPE=${2,,}
+                            shift
+                        fi;;
+        -p|--provider)  if [[ ! -z $2 && ! $2 =~ ^- ]]; then
+                            export PROVIDER=${2,,}
+                            shift
+                        fi;;
         -i|--log-info)  LOG_INFO=y;;
         -h|--help)      usage;;
         *)              usage "FATAL: unsupported or unknown argument: $1";;
@@ -235,7 +253,13 @@ copy_if_not_found "$DOMAINS_TXT" "$SH_DOMAINS"
 [ -z "$HOOK" ] && fatal "hook script not defined in $CONFIG"
 [ "$HOOK" != "$CC_HOOK" ] && warning "$CONFIG is not using $CC_HOOK"
 
-copy_if_not_found "$HOOK" "$SH_HOOK"
+case $CTYPE in
+    http-01) cp "$SH_HOOK" "$HOOK"
+             sed -i 's/^CHALLENGETYPE.*/CHALLENGETYPE=\"http-01\"/' "$CONFIG";;
+    dns-01)  cp "$SH_HOOK_DNS" "$HOOK"
+             sed -i 's/^CHALLENGETYPE.*/CHALLENGETYPE=\"dns-01\"/' "$CONFIG";;
+    *)       copy_if_not_found "$HOOK" "$SH_HOOK";;
+esac
 
 chmod +x $HOOK
 
@@ -285,7 +309,7 @@ else
 fi
 
 [ "$AUTHBIND_USR" = "$HTTP_USR" ] || chown $HTTP_USR $AUTHBIND80
-systemctl start add-water
+[ "$CTYPE" != "dns-01" ] && systemctl start add-water
 info "running dehydrated"
 if [ "$DEBUG" = "y" ] || [ "$LOG_INFO" = "y" ]; then
     dehydrated --cron $args --config $CONFIG 2>&1 | tee -a $DEBUG_LOG

plugins.d/Lets_Encrypt/dns_01.py

@@ -0,0 +1,87 @@
+#!/usr/bin/python3
+import sys
+import subprocess
+import re
+
+from subprocess import PIPE
+from os import path
+from shutil import which
+
+LEXICON_CONF = '/usr/share/confconsole/letsencrypt/lexicon.yml'
+
+LEXICON_CONF_NOTE = '''# Configure according to lexicon documentation https://dns-lexicon.readthedocs.io/
+# Note that documentation began around v.3.3.28 of lexicon. Therefore not all of
+# the features might be available to you!
+'''
+
+LEXICON_CONF_MAX_LINES = 7
+
+def load_config():
+    ''' Loads lexicon config if present '''
+    config = []
+    if not path.isfile(LEXICON_CONF):
+        while len(config) < LEXICON_CONF_MAX_LINES:
+            config.append('')
+        return config
+    else:
+        with open(LEXICON_CONF, 'r') as fob:
+            for line in fob:
+                line = line.rstrip()
+                if line and not line.startswith('#'):
+                    config.append(line)
+
+        while len(config) > LEXICON_CONF_MAX_LINES:
+            config.pop()
+        while len(config) < LEXICON_CONF_MAX_LINES:
+            config.append('')
+        return config
+
+def save_config(config):
+    ''' Saves lexicon configuration '''
+    with open(LEXICON_CONF, 'w') as fob:
+        fob.write(LEXICON_CONF_NOTE)
+        for line in config:
+            line = line.rstrip()
+            if line:
+                fob.write(line + '\n')
+
+def get_providers():
+    lexicon_bin = which('lexicon')
+    if not lexicon_bin:
+        ret = console.yesno(
+            'lexicon tool is required to use dns-01 challenge, '
+            'however it is not found on your system.\n\n'
+            'Do you wish to install it now?',
+            autosize=True
+        )
+        if ret != 'ok':
+            return None, 'Please install lexicon to use dns-01 challenge.'
+
+        apt = subprocess.run(['apt-get', '-y', 'install', 'lexicon'],
+                             encoding=sys.stdin.encoding,
+                             stderr=PIPE)
+        if apt.returncode != 0:
+            return None, apt.stderr.strip()
+
+    lexicon_bin = which('lexicon')
+    if not lexicon_bin:
+        return None, 'lexicon is not found on your system, is it installed?'
+
+    proc = subprocess.run([lexicon_bin, '--help'],
+                          encoding=sys.stdin.encoding,
+                          capture_output=True)
+    if proc.returncode != 0:
+        return None, proc.stderr.strip()
+
+    match = re.search(r"(?<={).*(?=})", proc.stdout.strip())
+    if not match:
+        return None, 'Could not obtain DNS providers list from lexicon!'
+
+    providers = []
+    for provider in match.group().split(','):
+        if len(provider) > 0:
+            providers.append((provider, '%s provider' % provider))
+
+    if providers:
+        return providers, None
+    return None, 'DNS providers list is empty!'

plugins.d/Lets_Encrypt/get_certificate.py

@@ -3,9 +3,12 @@
 import requests
 import sys
 import subprocess
+
 from subprocess import PIPE
 from os import path, remove
-from shutil import copyfile
+from shutil import copyfile, which
+
+import dns_01
 
 LE_INFO_URL = 'https://acme-v02.api.letsencrypt.org/directory'
 
@@ -72,6 +75,10 @@ def invalid_domains(domains):
             if len(domain) > 254:
                 return ('Error in {}: Domain names must not exceed 254'
                         ' characters'.format(domain))
+            if domain.count('.') < 1:
+                return ('Error in {}: Domain may not have less'
+                        ' than 2 segments'
+                        ''.format(domain))
             for part in domain.split('.'):
                 if not 0 < len(part) < 64:
                     return ('Error in {}: Domain segments may not be larger'
@@ -100,16 +107,6 @@ def run():
         console.msgbox('Error', msg, autosize=True)
         return
 
-    ret = console.yesno(
-        'DNS must be configured before obtaining certificates. '
-        'Incorrectly configured dns and excessive attempts could '
-        'lead to being temporarily blocked from requesting '
-        'certificates.\n\nDo you wish to continue?',
-        autosize=True
-    )
-    if ret != 'ok':
-        return
-
     ret = console.yesno(
         "Before getting a Let's Encrypt certificate, you must agree"
         ' to the current Terms of Service.\n\n'
@@ -132,6 +129,74 @@ def run():
         )
         return
 
+    ret, challenge = console.menu('Challenge type',
+                                  'Select challenge type to use', [
+        ('http-01', 'Requires public web access to this system'),
+        ('dns-01', 'Requires your DNS provider to provide an API')
+    ])
+    if ret != 'ok':
+        return
+
+    if challenge == 'http-01':
+        ret = console.yesno(
+            'DNS must be configured before obtaining certificates. '
+            'Incorrectly configured DNS and excessive attempts could '
+            'lead to being temporarily blocked from requesting '
+            'certificates.\n\nDo you wish to continue?',
+            autosize=True
+        )
+        if ret != 'ok':
+            return
+
+    if challenge == 'dns-01':
+        config = dns_01.load_config()
+        fields = [
+            ('', 1, 0, config[0], 1, 10, field_width, 255),
+            ('', 2, 0, config[1], 2, 10, field_width, 255),
+            ('', 3, 0, config[2], 3, 10, field_width, 255),
+            ('', 4, 0, config[3], 4, 10, field_width, 255),
+            ('', 5, 0, config[4], 5, 10, field_width, 255),
+            ('', 6, 0, config[5], 6, 10, field_width, 255),
+            ('', 7, 0, config[6], 7, 10, field_width, 255),
+        ]
+        ret, values = console.form('Lexicon configuration',
+                                   'Review and adjust current lexicon '
+                                   'configuration as necessary.\n\n'
+                                   'You can follow configuration reference at:\n'
+                                   'https://dns-lexicon.readthedocs.io/',
+                                   fields, autosize=True)
+        if ret != 'ok':
+            return
+
+        if config != values:
+            dns_01.save_config(values)
+
+        providers, err = dns_01.get_providers()
+        if err:
+            console.msgbox('Error', err, autosize=True)
+            return
+
+        ret, provider = console.menu('DNS providers list',
+                                     'Select DNS provider you\'d like to use',
+                                     providers)
+        if ret != 'ok':
+            return
+        elif provider == 'auto' and not which('nslookup'):
+            ret = console.yesno(
+                'nslookup tool is required to use dns-01 challenge with auto provider.\n\n'
+                'Do you wish to install it now?',
+                autosize=True
+            )
+            if ret != 'ok':
+                return
+
+            apt = subprocess.run(['apt-get', '-y', 'install', 'dnsutils'],
+                                 encoding=sys.stdin.encoding,
+                                 stderr=PIPE)
+            if apt.returncode != 0:
+                console.msgbox('Error', apt.stderr.strip(), autosize=True)
+                return
+
     domains = load_domains()
     m = invalid_domains(domains)
 
@@ -179,10 +244,13 @@ def run():
 
         # User has accepted ToS as part of this process, so pass '--register'
         # switch to Dehydrated wrapper
-        proc = subprocess.run(
-                    ['bash', path.join(
-                        path.dirname(PLUGIN_PATH), 'dehydrated-wrapper'),
-                     '--register'],
+        dehydrated_bin = ['bash', path.join(
+                            path.dirname(PLUGIN_PATH), 'dehydrated-wrapper'),
+                          '--register', '--challenge', challenge]
+        if challenge == 'dns-01':
+            dehydrated_bin.append('--provider')
+            dehydrated_bin.append(provider)
+        proc = subprocess.run(dehydrated_bin,
                     encoding=sys.stdin.encoding,
                     stderr=PIPE)
         if proc.returncode == 0:

share/letsencrypt/dehydrated-confconsole.config

@@ -19,3 +19,4 @@ BASEDIR=/var/lib/dehydrated
 WELLKNOWN="${BASEDIR}/acme-challenges"
 DOMAINS_TXT="/etc/dehydrated/confconsole.domains.txt"
 HOOK="/etc/dehydrated/confconsole.hook.sh"
+CHALLENGETYPE="http-01"