diff options
| -rw-r--r-- | Makefile | 3 | ||||
| -rw-r--r-- | interface-definitions/ssh.xml | 134 | ||||
| -rwxr-xr-x | src/conf-mode/vyos-config-ssh.py | 293 |
3 files changed, 430 insertions, 0 deletions
@@ -20,6 +20,9 @@ interface_definitions: sed -i '/^type: txt/d' $(TMPL_DIR)/system/ntp/server/node.tag/noselect/node.def sed -i '/^type: txt/d' $(TMPL_DIR)/system/ntp/server/node.tag/preempt/node.def sed -i '/^type: txt/d' $(TMPL_DIR)/system/ntp/server/node.tag/prefer/node.def + sed -i '/^type: txt/d' $(TMPL_DIR)/service/ssh/allow-root/node.def + sed -i '/^type: txt/d' $(TMPL_DIR)/service/ssh/disable-host-validation/node.def + sed -i '/^type: txt/d' $(TMPL_DIR)/service/ssh/disable-password-authentication/node.def .PHONY: all all: interface_definitions diff --git a/interface-definitions/ssh.xml b/interface-definitions/ssh.xml new file mode 100644 index 000000000..5ccd3006f --- /dev/null +++ b/interface-definitions/ssh.xml @@ -0,0 +1,134 @@ +<?xml version="1.0"?> + +<!--SSH configuration --> + +<interfaceDefinition> + <node name="service"> + <children> + <node name="ssh" owner="${vyos_sbindir}/vyos-config-ssh.py"> + <properties> + <help>Secure SHell (SSH) protocol</help> + <priority>500</priority> + </properties> + <children> + <node name="access-control"> + <properties> + <help>SSH user/group access controls. Directives are processed in this: deny-users, allow-users, deny-groups and allow-groups</help> + </properties> + <children> + <leafNode name="allow-groups"> + <properties> + <help>Configure sshd_config access control for allowed groups</help> + </properties> + </leafNode> + <leafNode name="allow-users"> + <properties> + <help>Configure sshd_config access control for allowed users</help> + </properties> + </leafNode> + <leafNode name="deny-groups"> + <properties> + <help>Configure sshd_config access control for disallowed groups</help> + </properties> + </leafNode> + <leafNode name="deny-users"> + <properties> + <help>Configure sshd_config access control for disallowed users</help> + </properties> + </leafNode> + </children> + </node> + <leafNode name="allow-root"> + <properties> + <help>Enable root login over ssh</help> + </properties> + </leafNode> + <leafNode name="ciphers"> + <properties> + <help>Allowed ciphers</help> + <completionHelp> + <script>ssh -Q cipher | tr '\n' ' '</script> + </completionHelp> + </properties> + </leafNode> + <leafNode name="disable-host-validation"> + <properties> + <help>Don't validate the remote host name with DNS</help> + </properties> + </leafNode> + <leafNode name="disable-password-authentication"> + <properties> + <help>Don't allow unknown user to login with password</help> + </properties> + </leafNode> + <leafNode name="key-exchange"> + <properties> + <help>Key exchange algorithms</help> + <completionHelp> + <script>ssh -Q kex | tr '\n' ' '</script> + </completionHelp> + </properties> + </leafNode> + <leafNode name="listen-address"> + <properties> + <help>Local addresses SSH service should listen on</help> + <valueHelp> + <format>ipv4</format> + <description>IP address to listen for incoming connections</description> + </valueHelp> + <valueHelp> + <format>ipv6</format> + <description>IPv6 address to listen for incoming connections</description> + </valueHelp> + <type>ipv4,ipv6</type> + <multi/> + </properties> + </leafNode> + <leafNode name="loglevel"> + <properties> + <help>Log level</help> + <valueHelp> + <format>QUIET</format> + <description>stay silent</description> + </valueHelp> + <valueHelp> + <format>FATAL</format> + <description>log fatals only</description> + </valueHelp> + <valueHelp> + <format>ERROR</format> + <description>log errors and fatals only</description> + </valueHelp> + <valueHelp> + <format>INFO</format> + <description>default log level</description> + </valueHelp> + <valueHelp> + <format>VERBOSE</format> + <description>enable logging of failed login attempts</description> + </valueHelp> + </properties> + </leafNode> + <leafNode name="mac"> + <properties> + <help>Allowed message authentication algorithms</help> + <completionHelp> + <script>ssh -Q mac | tr '\n' ' '</script> + </completionHelp> + </properties> + </leafNode> + <leafNode name="port"> + <properties> + <help>Port for SSH service</help> + <valueHelp> + <format>u32:1-65535</format> + <description>Numeric IP port</description> + </valueHelp> + <type>u32</type> + </properties> + </leafNode> + </children> + </node> + </children> + </node> +</interfaceDefinition> diff --git a/src/conf-mode/vyos-config-ssh.py b/src/conf-mode/vyos-config-ssh.py new file mode 100755 index 000000000..1605dcd74 --- /dev/null +++ b/src/conf-mode/vyos-config-ssh.py @@ -0,0 +1,293 @@ +#!/usr/bin/env python3 +# +# Copyright (C) 2018 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 jinja2 + +from vyos.config import Config +from vyos.util import ConfigError + +config_file = r'/etc/ssh/sshd_config' + +# Please be careful if you edit the template. +config_tmpl = """ + +### Autogenerated by vyos-config-ssh.py ### + +# Non-configurable defaults +Protocol 2 +HostKey /etc/ssh/ssh_host_rsa_key +HostKey /etc/ssh/ssh_host_dsa_key +HostKey /etc/ssh/ssh_host_ecdsa_key +HostKey /etc/ssh/ssh_host_ed25519_key +UsePrivilegeSeparation yes +KeyRegenerationInterval 3600 +ServerKeyBits 1024 +SyslogFacility AUTH +LoginGraceTime 120 +StrictModes yes +RSAAuthentication yes +PubkeyAuthentication yes +IgnoreRhosts yes +RhostsRSAAuthentication no +HostbasedAuthentication no +PermitEmptyPasswords no +ChallengeResponseAuthentication no +X11Forwarding yes +X11DisplayOffset 10 +PrintMotd no +PrintLastLog yes +TCPKeepAlive yes +Banner /etc/issue.net +Subsystem sftp /usr/lib/openssh/sftp-server +UsePAM yes +HostKey /etc/ssh/ssh_host_key + +# Specifies whether sshd should look up the remote host name, +# and to check that the resolved host name for the remote IP +# address maps back to the very same IP address. +UseDNS {{ host_validation }} + +# Specifies the port number that sshd listens on. The default is 22. +# Multiple options of this type are permitted. +Port {{ port }} + +# Gives the verbosity level that is used when logging messages from sshd +LogLevel {{ log_level }} + +# Specifies whether root can log in using ssh +PermitRootLogin {{ allow_root }} + +# Specifies whether password authentication is allowed +PasswordAuthentication {{ password_authentication }} + +{% if listen_on -%} +# Specifies the local addresses sshd should listen on +{% for a in listen_on -%} +ListenAddress {{ a }} +{% endfor -%} +{% endif %} + +{% if ciphers -%} +# Specifies the ciphers allowed. Multiple ciphers must be comma-separated. +# +# NOTE: As of now, there is no 'multi' node for 'ciphers', thus we have only one :/ +Ciphers {{ ciphers }} +{% endif %} + +{% if mac -%} +# Specifies the available MAC (message authentication code) algorithms. The MAC +# algorithm is used for data integrity protection. Multiple algorithms must be +# comma-separated. +# +# NOTE: As of now, there is no 'multi' node for 'mac', thus we have only one :/ +MACs {{ mac }} +{% endif %} + +{% if key_exchange -%} +# Specifies the available KEX (Key Exchange) algorithms. Multiple algorithms must +# be comma-separated. +# +# NOTE: As of now, there is no 'multi' node for 'key-exchange', thus we have only one :/ +KexAlgorithms {{ key_exchange }} +{% endif %} + +{% if allow_users -%} +# This keyword can be followed by a list of user name patterns, separated by spaces. +# If specified, login is allowed only for user names that match one of the patterns. +# Only user names are valid, a numerical user ID is not recognized. +AllowUsers {{ allow_users | join(" ") }} +{% endif %} + +{% if allow_groups -%} +# This keyword can be followed by a list of group name patterns, separated by spaces. +# If specified, login is allowed only for users whose primary group or supplementary +# group list matches one of the patterns. Only group names are valid, a numerical group +# ID is not recognized. +AllowGroups {{ allow_groups | join(" ") }} +{% endif %} + +{% if deny_users -%} +# This keyword can be followed by a list of user name patterns, separated by spaces. +# Login is disallowed for user names that match one of the patterns. Only user names +# are valid, a numerical user ID is not recognized. +DenyUsers {{ deny_users | join(" ") }} +{% endif %} + +{% if deny_groups -%} +# This keyword can be followed by a list of group name patterns, separated by spaces. +# Login is disallowed for users whose primary group or supplementary group list matches +# one of the patterns. Only group names are valid, a numerical group ID is not recognized. +DenyGroups {{ deny_groups | join(" ") }} +{% endif %} +""" + +default_config_data = { + 'port' : '22', + 'log_level': 'INFO', + 'allow_root': 'no', + 'password_authentication': 'yes', + 'host_validation': 'yes' +} + +def get_config(): + ssh = default_config_data + conf = Config() + if not conf.exists('service ssh'): + return None + else: + conf.set_level('service ssh') + + if conf.exists('access-control allow-users'): + # Retrieve ',' separated list for allowed users and convert it to a list. + # The current VyOS CLI implementation should be improved to rather use multi nodes + # instead of a ',' separated input. + allow_user = conf.return_value('access-control allow-users') + tmp = allow_user.split(',') + users = [] + for u in tmp: + users.append(u) + + ssh.setdefault('allow_users', users) + + if conf.exists('access-control allow-groups'): + # Retrieve ',' separated list for allowed groups and convert it to a list. + # The current VyOS CLI implementation should be improved to rather use multi nodes + # instead of a ',' separated input. + allow_group = conf.return_value('access-control allow-groups') + tmp = allow_group.split(',') + groups = [] + for g in tmp: + groups.append(g) + + ssh.setdefault('allow_groups', groups) + + if conf.exists('access-control deny-users'): + # Retrieve ',' separated list for denied users and convert it to a list. + # The current VyOS CLI implementation should be improved to rather use multi nodes + # instead of a ',' separated input. + deny_user = conf.return_value('access-control deny-users') + tmp = deny_user.split(',') + users = [] + for u in tmp: + users.append(u) + + ssh.setdefault('deny_users', users) + + if conf.exists('access-control deny-groups'): + # Retrieve ',' separated list for denied groups and convert it to a list. + # The current VyOS CLI implementation should be improved to rather use multi nodes + # instead of a ',' separated input. + deny_group = conf.return_value('access-control deny-groups') + tmp = deny_group.split(',') + groups = [] + for g in tmp: + groups.append(g) + + ssh.setdefault('deny_groups', groups) + + if conf.exists('allow-root'): + ssh['allow-root'] = 'yes' + + if conf.exists('ciphers'): + # TODO: OpenSSH supports having multiple Ciphers configured. VyOS CLI + # yet has no multi node for this. See T632 in phabricator. + ciphers = conf.return_value('ciphers') + ssh.setdefault('ciphers', ciphers) + + if conf.exists('disable-host-validation'): + ssh['host_validation'] = 'no' + + if conf.exists('disable-password-authentication'): + ssh['password_authentication'] = 'no' + + if conf.exists('key-exchange'): + # TODO: OpenSSH supports having multiple KEYX methods configured. VyOS CLI + # yet has no multi node for this. See T632 in phabricator. + kex = conf.return_value('key-exchange') + ssh.setdefault('key_exchange', kex) + + if conf.exists('listen-address'): + # We can listen on both IPv4 and IPv6 addresses + # Maybe there could be a check in the future if the configured IP address + # is configured on this system at all? + addresses = conf.return_values('listen-address') + listen = [] + + for addr in addresses: + listen.append(addr) + + ssh.setdefault('listen_on', listen) + + if conf.exists('loglevel'): + ssh['log_level'] = conf.return_value('loglevel') + + if conf.exists('mac'): + # TODO: OpenSSH supports having multiple MACs configured. VyOS CLI + # yet has no multi node for this. See T632 in phabricator. + mac = conf.return_value('mac') + ssh.setdefault('mac', mac) + + if conf.exists('port'): + port = conf.return_value('port') + ssh.setdefault('port', port) + + return ssh + +def verify(ssh): + if ssh is None: + return None + + if 'loglevel' in ssh.keys(): + allowed_loglevel = 'QUIET, FATAL, ERROR, INFO, VERBOSE' + if not ssh['loglevel'] in allowed_loglevel: + raise ConfigError('loglevel must be one of "{0}"\n'.format(allowed_loglevel)) + + return None + +def generate(ssh): + if ssh is None: + return None + + tmpl = jinja2.Template(config_tmpl) + config_text = tmpl.render(ssh) + with open(config_file, 'w') as f: + f.write(config_text) + return None + +def apply(ssh): + if ssh is not None and 'port' in ssh.keys(): + os.system("sudo systemctl restart ssh") + else: + # SSH access is removed in the commit + os.system("sudo systemctl stop ssh") + os.unlink(config_file) + + return None + +if __name__ == '__main__': + try: + c = get_config() + verify(c) + generate(c) + apply(c) + except ConfigError as e: + print(e) + sys.exit(1) |