login: T1948: migrade local and radius configurations

Splitting was not a good idea. By combining both we can create a RADIUS server
XML include file which can be reused by multiple implementations to get a
uniformed CLI for the users.

1 files changed, 355 insertions, 0 deletions

diff --git a/src/conf_mode/system-login.py b/src/conf_mode/system-login.py
new file mode 100755
index 000000000..23152fee0
--- /dev/null
+++ b/src/conf_mode/system-login.py
@@ -0,0 +1,355 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2020 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 pwd import getpwall, getpwnam
+from stat import S_IRUSR, S_IWUSR, S_IRWXU, S_IRGRP, S_IXGRP
+from subprocess import Popen, PIPE, STDOUT
+from psutil import users
+
+from vyos.config import Config
+from vyos.configdict import list_diff
+from vyos import ConfigError
+
+radius_config_file = "/etc/pam_radius_auth.conf"
+radius_config_tmpl = """
+# Automatically generated by VyOS
+# RADIUS configuration file
+{%- if radius_server %}
+# server[:port]         shared_secret                           timeout (s)     source_ip
+{% for s in radius_server %}
+{%- if not s.disabled -%}
+{{ s.address }}:{{ s.port }} {{ s.key }} {{ s.timeout }} {% if radius_source_address -%}{{ radius_source_address }}{% endif %}
+{% endif %}
+{%- endfor %}
+
+priv-lvl 15
+mapped_priv_user radius_priv_user
+{% endif %}
+
+"""
+
+default_config_data = {
+    'deleted': False,
+    'add_users': [],
+    'del_users': [],
+    'radius_server': [],
+    'radius_source_address': '',
+}
+
+def get_local_users():
+    """Returns list of dynamically allocated users (see Debian Policy Manual)"""
+    local_users = []
+    for p in getpwall():
+        username = p[0]
+        uid = getpwnam(username).pw_uid
+        if uid in range(1000, 29999):
+            if username not in ['radius_user', 'radius_priv_user']:
+                local_users.append(username)
+
+    return local_users
+
+
+def get_crypt_pw(password):
+    command = '/usr/bin/mkpasswd --method=sha-512 {}'.format(password)
+    p = Popen(command, stdout=PIPE, stderr=STDOUT, shell=True)
+    tmp = p.communicate()[0].strip()
+    return tmp.decode()
+
+
+def get_config():
+    login = default_config_data
+    conf = Config()
+    base_level = ['system', 'login']
+
+    # We do not need to check if the nodes exist or not and bail out early
+    # ... this would interrupt the following logic on determine which users
+    # should be deleted and which users should stay.
+    #
+    # All fine so far!
+
+    # Read in all local users and store to list
+    for username in conf.list_nodes(base_level + ['user']):
+        user = {
+            'name': username,
+            'password_plaintext': '',
+            'password_encrypted': '!',
+            'public_keys': [],
+            'full_name': '',
+            'home_dir': '/home/' + username,
+        }
+        conf.set_level(base_level + ['user', username])
+
+        # Plaintext password
+        if conf.exists(['authentication', 'plaintext-password']):
+            user['password_plaintext'] = conf.return_value(['authentication', 'plaintext-password'])
+
+        # Encrypted password
+        if conf.exists(['authentication', 'encrypted-password']):
+            user['password_encrypted'] = conf.return_value(['authentication', 'encrypted-password'])
+
+        # User real name
+        if conf.exists(['full-name']):
+            user['full_name'] = conf.return_value(['full-name'])
+
+        # User home-directory
+        if conf.exists(['home-directory']):
+            user['home_dir'] = conf.return_value(['home-directory'])
+
+        # Read in public keys
+        for id in conf.list_nodes(['authentication', 'public-keys']):
+            key = {
+                'name': id,
+                'key': '',
+                'options': '',
+                'type': ''
+            }
+            conf.set_level(base_level + ['user', username, 'authentication', 'public-keys', id])
+
+            # Public Key portion
+            if conf.exists(['key']):
+                key['key'] = conf.return_value(['key'])
+
+            # Options for individual public key
+            if conf.exists(['options']):
+                key['options'] = conf.return_value(['options'])
+
+            # Type of public key
+            if conf.exists(['type']):
+                key['type'] = conf.return_value(['type'])
+
+            # Append individual public key to list of user keys
+            user['public_keys'].append(key)
+
+        login['add_users'].append(user)
+
+    #
+    # RADIUS configuration
+    #
+    conf.set_level(base_level + ['radius'])
+
+    if conf.exists(['source-address']):
+        login['radius_source_address'] = conf.return_value(['source-address'])
+
+    # Read in all RADIUS servers and store to list
+    for server in conf.list_nodes(['server']):
+        server_cfg = {
+            'address': server,
+            'disabled': False,
+            'key': '',
+            'port': '1812',
+            'timeout': '2'
+        }
+        conf.set_level(base_level + ['radius', 'server', server])
+
+        # Check if RADIUS server was temporary disabled
+        if conf.exists(['disable']):
+            server_cfg['disabled'] = True
+
+        # RADIUS shared secret
+        if conf.exists(['key']):
+            server_cfg['key'] = conf.return_value(['key'])
+
+        # RADIUS authentication port
+        if conf.exists(['port']):
+            server_cfg['port'] = conf.return_value(['port'])
+
+        # RADIUS session timeout
+        if conf.exists(['timeout']):
+            server_cfg['timeout'] = conf.return_value(['timeout'])
+
+        # Append individual RADIUS server configuration to global server list
+        login['radius_server'].append(server_cfg)
+
+    # users no longer existing in the running configuration need to be deleted
+    local_users = get_local_users()
+    cli_users = [tmp['name'] for tmp in login['add_users']]
+    # create a list of all users, cli and users
+    all_users = list(set(local_users+cli_users))
+
+    # Remove any normal users that dos not exist in the current configuration.
+    # This can happen if user is added but configuration was not saved and
+    # system is rebooted.
+    login['del_users'] = [tmp for tmp in all_users if tmp not in cli_users]
+
+
+    return login
+
+def verify(login):
+    cur_user = os.environ['SUDO_USER']
+    if cur_user in login['del_users']:
+        raise ConfigError('Attempting to delete current user: {}'.format(cur_user))
+
+    # At lease one RADIUS server must not be disabled
+    if len(login['radius_server']) > 0:
+        fail = True
+        for server in login['radius_server']:
+            if not server['disabled']:
+                fail = False
+        if fail:
+            raise ConfigError('At least one RADIUS server must be active.')
+
+
+    return None
+
+def generate(login):
+    # calculate users encrypted password
+    for user in login['add_users']:
+        if user['password_plaintext']:
+            user['password_encrypted'] = get_crypt_pw(user['password_plaintext'])
+            user['password_plaintext'] = ''
+
+            # remove old plaintext password
+            # and set new encrypted password
+            os.system("vyos_libexec_dir=/usr/libexec/vyos /opt/vyatta/sbin/my_set system login user '{}' authentication plaintext-password '' >/dev/null".format(user['name']))
+            os.system("vyos_libexec_dir=/usr/libexec/vyos /opt/vyatta/sbin/my_set system login user '{}' authentication encrypted-password '{}' >/dev/null".format(user['name'], user['password_encrypted']))
+
+    if len(login['radius_server']) > 0:
+        tmpl = jinja2.Template(radius_config_tmpl)
+        config_text = tmpl.render(login)
+        with open(radius_config_file, 'w') as f:
+            f.write(config_text)
+
+        uid = getpwnam('root').pw_uid
+        gid = getpwnam('root').pw_gid
+        os.chown(radius_config_file, uid, gid)
+        os.chmod(radius_config_file, S_IRUSR | S_IWUSR)
+    else:
+        if os.path.isfile(radius_config_file):
+            os.unlink(radius_config_file)
+
+    return None
+
+def apply(login):
+    for user in login['add_users']:
+        # make new user using vyatta shell and make home directory (-m),
+        # default group of 100 (users)
+        cmd = "useradd -m -N"
+        # check if user already exists:
+        if user['name'] in get_local_users():
+            # update existing account
+            cmd = "usermod"
+
+        # we need to use '' quotes when passing formatted data to the shell
+        # else it will not work as some data parts are lost in translation
+        cmd += " -p '{}'".format(user['password_encrypted'])
+        cmd += " -s /bin/vbash"
+        if user['full_name']:
+            cmd += " -c '{}'".format(user['full_name'])
+
+        if user['home_dir']:
+            cmd += " -d '{}'".format(user['home_dir'])
+
+        cmd += " -G frrvty,vyattacfg,sudo,adm,dip,disk"
+        cmd += " {}".format(user['name'])
+
+        try:
+            os.system(cmd)
+
+            uid = getpwnam(user['name']).pw_uid
+            gid = getpwnam(user['name']).pw_gid
+
+            # install ssh keys
+            key_dir = '{}/.ssh'.format(user['home_dir'])
+            if not os.path.isdir(key_dir):
+                os.mkdir(key_dir)
+                os.chown(key_dir, uid, gid)
+                os.chmod(key_dir, S_IRWXU | S_IRGRP | S_IXGRP)
+
+            key_file = key_dir + '/authorized_keys';
+            with open(key_file, 'w') as f:
+                f.write("# Automatically generated by VyOS\n")
+                f.write("# Do not edit, all changes will be lost\n")
+
+                for id in user['public_keys']:
+                    line = ''
+                    if id['options']:
+                        line = '{} '.format(id['options'])
+
+                    line += '{} {} {}\n'.format(id['type'], id['key'], id['name'])
+                    f.write(line)
+
+            os.chown(key_file, uid, gid)
+            os.chmod(key_file, S_IRUSR | S_IWUSR)
+
+        except Exception as e:
+            raise ConfigError('Adding user "{}" raised an exception: {}'.format(user['name'], e))
+
+    for user in login['del_users']:
+        try:
+            # Logout user if he is logged in
+            if user in list(set([tmp[0] for tmp in users()])):
+                print('{} is logged in, forcing logout'.format(user))
+                os.system('pkill -HUP -u {}'.format(user))
+
+            # Remove user account but leave home directory to be safe
+            os.system('userdel -r {} 2>/dev/null'.format(user))
+
+        except Exception as e:
+            raise ConfigError('Deleting user "{}" raised an exception: {}'.format(user, e))
+
+    #
+    # RADIUS configuration
+    #
+    if len(login['radius_server']) > 0:
+        try:
+            # Enable RADIUS in PAM
+            os.system("DEBIAN_FRONTEND=noninteractive pam-auth-update --package --enable radius")
+
+            # Make NSS system aware of RADIUS, too
+            cmd = "sed -i -e \'/\smapname/b\' \
+                          -e \'/^passwd:/s/\s\s*/&mapuid /\' \
+                          -e \'/^passwd:.*#/s/#.*/mapname &/\' \
+                          -e \'/^passwd:[^#]*$/s/$/ mapname &/\' \
+                          -e \'/^group:.*#/s/#.*/ mapname &/\' \
+                          -e \'/^group:[^#]*$/s/: */&mapname /\' \
+                          /etc/nsswitch.conf"
+
+            os.system(cmd)
+
+        except Exception as e:
+            raise ConfigError('RADIUS configuration failed: {}'.format(e))
+
+    else:
+        try:
+            # Disable RADIUS in PAM
+            os.system("DEBIAN_FRONTEND=noninteractive pam-auth-update --package --remove radius")
+
+            cmd = "sed -i -e \'/^passwd:.*mapuid[ \t]/s/mapuid[ \t]//\' \
+                   -e \'/^passwd:.*[ \t]mapname/s/[ \t]mapname//\' \
+                   -e \'/^group:.*[ \t]mapname/s/[ \t]mapname//\' \
+                   -e \'s/[ \t]*$//\' \
+                   /etc/nsswitch.conf"
+
+            os.system(cmd)
+
+        except Exception as e:
+            raise ConfigError('Removing RADIUS configuration failed'.format(e))
+
+    return None
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        sys.exit(1)