freeipa/ipaserver/advise/plugins/smart_card_auth.py
Martin Babinsky 53c5c0ad7b smart-card-advises: ensure that krb5-pkinit is installed on client
This library is a prerequisite for successful Smart Card authentication
on the client. The client-side advise should make sure this dependency
is present.

https://pagure.io/freeipa/issue/7036

Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
2017-07-04 09:48:04 +02:00

326 lines
12 KiB
Python

#
# Copyright (C) 2017 FreeIPA Contributors see COPYING for license
#
import os
from ipalib.plugable import Registry
from ipaplatform import services
from ipaplatform.paths import paths
from ipaserver.advise.base import Advice
from ipaserver.install.httpinstance import NSS_OCSP_ENABLED
register = Registry()
class common_smart_card_auth_config(Advice):
"""
Common steps required to properly configure both server and client for
smart card auth
"""
systemwide_nssdb = paths.NSS_DB_DIR
smart_card_ca_certs_variable_name = "SC_CA_CERTS"
single_ca_cert_variable_name = 'ca_cert'
def check_ccache_not_empty(self):
self.log.comment('Check whether the credential cache is not empty')
self.log.exit_on_failed_command(
'klist',
[
"Credential cache is empty",
'Use kinit as privileged user to obtain Kerberos credentials'
])
def check_and_set_ca_cert_paths(self):
ca_paths_variable = self.smart_card_ca_certs_variable_name
single_ca_path_variable = self.single_ca_cert_variable_name
self.log.command("{}=$@".format(ca_paths_variable))
self.log.exit_on_predicate(
'[ -z "${}" ]'.format(ca_paths_variable),
['You need to provide one or more paths to the PEM files '
'containing CAs signing the Smart Cards']
)
with self.log.for_loop(single_ca_path_variable,
'${}'.format(ca_paths_variable)):
self.log.exit_on_predicate(
'[ ! -f "${}" ]'.format(single_ca_path_variable),
['Invalid CA certificate filename: ${}'.format(
single_ca_path_variable),
'Please check that the path exists and is a valid file']
)
def upload_smartcard_ca_certificates_to_systemwide_db(self):
with self.log.for_loop(
self.single_ca_cert_variable_name,
'${}'.format(self.smart_card_ca_certs_variable_name)):
self.log.command(
'certutil -d {} -A -i ${} -n "Smart Card CA $(uuidgen)" '
'-t CT,C,C'.format(
self.systemwide_nssdb, self.single_ca_cert_variable_name
)
)
def install_smart_card_signing_ca_certs(self):
with self.log.for_loop(
self.single_ca_cert_variable_name,
'${}'.format(self.smart_card_ca_certs_variable_name)):
self.log.exit_on_failed_command(
'ipa-cacert-manage install ${} -t CT,C,C'.format(
self.single_ca_cert_variable_name
),
['Failed to install external CA certificate to IPA']
)
def update_ipa_ca_certificate_store(self):
self.log.exit_on_failed_command(
'ipa-certupdate',
['Failed to update IPA CA certificate database']
)
@register()
class config_server_for_smart_card_auth(common_smart_card_auth_config):
"""
Configures smart card authentication via Kerberos (PKINIT) and for WebUI
"""
description = ("Instructions for enabling Smart Card authentication on "
" a single FreeIPA server. Includes Apache configuration, "
"enabling PKINIT on KDC and configuring WebUI to accept "
"Smart Card auth requests. To enable the feature in the "
"whole topology you have to run the script on each master")
nss_conf = paths.HTTPD_NSS_CONF
nss_ocsp_directive = 'NSSOCSP'
nss_nickname_directive = 'NSSNickname'
kdc_service_name = services.knownservices.krb5kdc.systemd_name
def get_info(self):
self.log.exit_on_nonroot_euid()
self.check_and_set_ca_cert_paths()
self.check_ccache_not_empty()
self.check_hostname_is_in_masters()
self.resolve_ipaca_records()
self.enable_nss_ocsp()
self.mark_httpd_cert_as_trusted()
self.restart_httpd()
self.record_httpd_ocsp_status()
self.check_and_enable_pkinit()
self.enable_ok_to_auth_as_delegate_on_http_principal()
self.upload_smartcard_ca_certificates_to_systemwide_db()
self.install_smart_card_signing_ca_certs()
self.update_ipa_ca_certificate_store()
self.restart_kdc()
def check_hostname_is_in_masters(self):
self.log.comment('Check whether the host is IPA master')
self.log.exit_on_failed_command(
'ipa server-find $(hostname -f)',
["This script can be run on IPA master only"])
def resolve_ipaca_records(self):
ipa_domain_name = self.api.env.domain
self.log.comment('make sure bind-utils are installed so that we can '
'dig for ipa-ca records')
self.log.exit_on_failed_command(
'yum install -y bind-utils',
['Failed to install bind-utils'])
self.log.comment('make sure ipa-ca records are resolvable, '
'otherwise error out and instruct')
self.log.comment('the user to update the DNS infrastructure')
self.log.command('ipaca_records=$(dig +short '
'ipa-ca.{})'.format(ipa_domain_name))
self.log.exit_on_predicate(
'[ -z "$ipaca_records" ]',
[
'Can not resolve ipa-ca records for ${domain_name}',
'Please make sure to update your DNS infrastructure with ',
'ipa-ca record pointing to IP addresses of IPA CA masters'
])
def enable_nss_ocsp(self):
self.log.comment('look for the OCSP directive in nss.conf')
self.log.comment(' if it is present, switch it on')
self.log.comment(
'if it is absent, append it to the end of VirtualHost section')
predicate = self._interpolate_ocsp_directive_file_into_command(
"grep -q '{directive} ' {filename}")
self.log.commands_on_predicate(
predicate,
[
self._interpolate_ocsp_directive_file_into_command(
"sed -i.ipabkp -r "
"'s/^#*[[:space:]]*{directive}[[:space:]]+(on|off)$"
"/{directive} on/' {filename}")
],
commands_to_run_when_false=[
self._interpolate_ocsp_directive_file_into_command(
"sed -i.ipabkp '/<\/VirtualHost>/i {directive} on' "
"{filename}")
]
)
def _interpolate_ocsp_directive_file_into_command(self, fmt_line):
return self._format_command(
fmt_line, self.nss_ocsp_directive, self.nss_conf)
def _format_command(self, fmt_line, directive, filename):
return fmt_line.format(directive=directive, filename=filename)
def mark_httpd_cert_as_trusted(self):
httpd_nss_database_pwd_file = os.path.join(
paths.HTTPD_ALIAS_DIR, 'pwdfile.txt')
self.log.comment(
'mark the HTTP certificate as trusted peer to avoid '
'chicken-egg startup issue')
self.log.command(
self._interpolate_nssnickname_directive_file_into_command(
"http_cert_nick=$(grep '{directive}' {filename} |"
" cut -f 2 -d ' ')"))
self.log.exit_on_failed_command(
'certutil -M -n $http_cert_nick -d "{}" -f {} -t "Pu,u,u"'.format(
paths.HTTPD_ALIAS_DIR,
httpd_nss_database_pwd_file),
['Can not set trust flags on HTTP certificate'])
def _interpolate_nssnickname_directive_file_into_command(self, fmt_line):
return self._format_command(
fmt_line, self.nss_nickname_directive, self.nss_conf)
def restart_httpd(self):
self.log.comment('finally restart apache')
self.log.command('systemctl restart httpd')
def record_httpd_ocsp_status(self):
self.log.comment('store the OCSP upgrade state')
self.log.command(
"python -c 'from ipaserver.install import sysupgrade; "
"sysupgrade.set_upgrade_state(\"httpd\", "
"\"{}\", True)'".format(NSS_OCSP_ENABLED))
def check_and_enable_pkinit(self):
self.log.comment('check whether PKINIT is configured on the master')
with self.log.if_branch(
"ipa-pkinit-manage status | grep -q 'enabled'"):
self.log.command('echo "PKINIT already enabled"')
with self.log.else_branch():
self.log.exit_on_failed_command(
'ipa-pkinit-manage enable',
['Failed to issue PKINIT certificates to local KDC'])
def enable_ok_to_auth_as_delegate_on_http_principal(self):
self.log.comment('Enable OK-AS-DELEGATE flag on the HTTP principal')
self.log.comment('This enables smart card login to WebUI')
self.log.command(
'output=$(ipa service-mod HTTP/$(hostname -f) '
'--ok-to-auth-as-delegate=True 2>&1)')
self.log.exit_on_predicate(
'[ "$?" -ne "0" -a '
'-z "$(echo $output | grep \'no modifications\')" ]',
["Failed to set OK_AS_AUTH_AS_DELEGATE flag on HTTP principal"]
)
def restart_kdc(self):
self.log.exit_on_failed_command(
'systemctl restart {}'.format(self.kdc_service_name),
['Failed to restart KDC. Please restart the service manually.']
)
@register()
class config_client_for_smart_card_auth(common_smart_card_auth_config):
"""
Configures smart card authentication on FreeIPA client
"""
description = ("Instructions for enabling Smart Card authentication on "
" a single FreeIPA client. Configures Smart Card daemon, "
"set the system-wide trust store and configures SSSD to "
"allow smart card logins to desktop")
opensc_module_name = "OpenSC"
pkcs11_shared_lib = '/usr/lib64/opensc-pkcs11.so'
smart_card_service_file = 'pcscd.service'
smart_card_socket = 'pcscd.socket'
def get_info(self):
self.log.exit_on_nonroot_euid()
self.check_and_set_ca_cert_paths()
self.check_ccache_not_empty()
self.check_and_remove_pam_pkcs11()
self.install_opensc_and_dconf_packages()
self.install_krb5_client_dependencies()
self.start_enable_smartcard_daemon()
self.add_pkcs11_module_to_systemwide_db()
self.upload_smartcard_ca_certificates_to_systemwide_db()
self.update_ipa_ca_certificate_store()
self.run_authconfig_to_configure_smart_card_auth()
self.restart_sssd()
def check_and_remove_pam_pkcs11(self):
self.log.command('rpm -qi pam_pkcs11 > /dev/null')
self.log.commands_on_predicate(
'[ "$?" -eq "0" ]',
[
'yum remove -y pam_pkcs11'
]
)
def install_opensc_and_dconf_packages(self):
self.log.comment(
'authconfig often complains about missing dconf, '
'install it explicitly')
self.log.exit_on_failed_command(
'yum install -y {} dconf'.format(self.opensc_module_name.lower()),
['Could not install OpenSC package']
)
def install_krb5_client_dependencies(self):
self.log.exit_on_failed_command(
'yum install -y krb5-pkinit-openssl',
['Failed to install Kerberos client PKINIT extensions.']
)
def start_enable_smartcard_daemon(self):
self.log.command(
'systemctl start {service} {socket} '
'&& systemctl enable {service} {socket}'.format(
service=self.smart_card_service_file,
socket=self.smart_card_socket))
def add_pkcs11_module_to_systemwide_db(self):
module_name = self.opensc_module_name
nssdb = self.systemwide_nssdb
shared_lib = self.pkcs11_shared_lib
self.log.commands_on_predicate(
'modutil -dbdir {} -list | grep -q {}'.format(
nssdb, module_name),
[
'echo "{} PKCS#11 module already configured"'.format(
module_name)
],
commands_to_run_when_false=[
'echo "" | modutil -dbdir {} -add "{}" -libfile {}'.format(
nssdb, module_name, shared_lib),
]
)
def run_authconfig_to_configure_smart_card_auth(self):
self.log.exit_on_failed_command(
'authconfig --enablesmartcard --smartcardmodule=sssd --updateall',
[
'Failed to configure Smart Card authentication in SSSD'
]
)
def restart_sssd(self):
self.log.command('systemctl restart sssd.service')