Add ipa-cert-fix tool

The ipa-cert-fix tool wraps `pki-server cert-fix`, performing
additional certificate requests for non-Dogtag IPA certificates and
performing additional actions.  In particular:

- Run cert-fix with arguments particular to the IPA deployment.

- Update IPA RA certificate in the ipara user entry (if renewed).

- Add shared certificates (if renewed) to the ca_renewal LDAP
  container for replication.

- Become the CA renewal master if shared certificates were renewed.
  This ensures other CA replicas, including the previous CA renewal
  master if not the current host, pick up those new certificates
  when Certmonger attempts to renew them.

Fixes: https://pagure.io/freeipa/issue/7885
Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>

freeipa.spec.in

@@ -1001,6 +1001,7 @@ fi
 %{_sbindir}/ipa-winsync-migrate
 %{_sbindir}/ipa-pkinit-manage
 %{_sbindir}/ipa-crlgen-manage
+%{_sbindir}/ipa-cert-fix
 %{_libexecdir}/certmonger/dogtag-ipa-ca-renew-agent-submit
 %{_libexecdir}/certmonger/ipa-server-guard
 %{_libexecdir}/ipa/custodia/ipa-custodia-dmldap

install/tools/Makefile.am

@@ -29,6 +29,7 @@ dist_noinst_DATA =		\
 	ipa-winsync-migrate.in	\
 	ipa-pkinit-manage.in	\
 	ipa-crlgen-manage.in	\
+	ipa-cert-fix.in		\
 	ipa-custodia.in		\
 	ipa-custodia-check.in	\
 	ipa-httpd-kdcproxy.in	\
@@ -61,6 +62,7 @@ nodist_sbin_SCRIPTS =		\
 	ipa-winsync-migrate	\
 	ipa-pkinit-manage	\
 	ipa-crlgen-manage	\
+	ipa-cert-fix		\
 	$(NULL)
 
 appdir = $(libexecdir)/ipa/

install/tools/ipa-cert-fix.in

@@ -0,0 +1,8 @@
+@PYTHONSHEBANG@
+#
+# Copyright (C) 2019  FreeIPA Contributors see COPYING for license
+#
+
+from ipaserver.install.ipa_cert_fix import IPACertFix
+
+IPACertFix.run_cli()

ipaserver/install/ipa_cert_fix.py

@@ -0,0 +1,275 @@
+#
+# Copyright (C) 2019  FreeIPA Contributors see COPYING for license
+#
+
+# ipa-cert-fix performs the following steps:
+#
+# 1. Confirm running as root (AdminTool.validate_options does this)
+#
+# 2. Confirm that DS is up.
+#
+# 3. Determine which of following certs (if any) need renewing
+#     - IPA RA
+#     - Apache HTTPS
+#     - 389 LDAPS
+#     - Kerberos KDC (PKINIT)
+#
+# 4. Execute `pki-server cert-fix` with relevant options,
+#    including `--extra-cert SERIAL` for each cert from #3.
+#
+# 5. Print details of renewed certificates.
+#
+# 6. Install renewed certs from #3 in relevant places
+#
+# 7. ipactl restart
+
+from __future__ import print_function, absolute_import
+
+import datetime
+from enum import Enum
+import logging
+import shutil
+
+from ipalib import api
+from ipalib import x509
+from ipaplatform.paths import paths
+from ipapython.admintool import AdminTool
+from ipapython.certdb import NSSDatabase, EMPTY_TRUST_FLAGS
+from ipapython.dn import DN
+from ipaserver.install import ca, cainstance, dsinstance, installutils
+from ipaserver.install.installutils import is_ipa_configured
+from ipapython import ipautil
+
+msg = """
+                          WARNING
+
+ipa-cert-fix is intended for recovery when expired certificates
+prevent the normal operation of FreeIPA.  It should ONLY be used
+in such scenarios, and backup of the system, especially certificates
+and keys, is STRONGLY RECOMMENDED.
+
+"""
+
+logger = logging.getLogger(__name__)
+
+
+class IPACertType(Enum):
+    IPARA = "IPA RA"
+    HTTPS = "Apache HTTPS"
+    LDAPS = "LDAP"
+    KDC = "KDC"
+
+
+class IPACertFix(AdminTool):
+    command_name = "ipa-cert-fix"
+    usage = "%prog"
+    description = "Renew expired certificates."
+
+    def validate_options(self):
+        super(IPACertFix, self).validate_options(needs_root=True)
+
+    def run(self):
+        if not is_ipa_configured():
+            print("IPA is not configured.")
+            return 0  # not really an error
+
+        if not cainstance.is_ca_installed_locally():
+            print("CA is not installed on this server.")
+            return 0  # not really an error
+
+        try:
+            ipautil.run(['pki-server', 'cert-fix', '--help'], raiseonerr=True)
+        except ipautil.CalledProcessError:
+            print(
+                "The 'pki-server cert-fix' command is not available; "
+                "cannot proceed."
+            )
+            return 1
+
+        api.bootstrap(in_server=True, confdir=paths.ETC_IPA)
+        api.finalize()
+        api.Backend.ldap2.connect()  # ensure DS is up
+
+        subject_base = dsinstance.DsInstance().find_subject_base()
+        if not subject_base:
+            raise RuntimeError("Cannot determine certificate subject base.")
+
+        ca_subject_dn = ca.lookup_ca_subject(api, subject_base)
+
+        now = datetime.datetime.now() + datetime.timedelta(weeks=2)
+        certs, extra_certs = expired_certs(now)
+
+        if not certs and not extra_certs:
+            print("Nothing to do.")
+            return 0
+
+        print(msg)
+
+        print_intentions(certs, extra_certs)
+
+        response = ipautil.user_input('Enter "yes" to proceed')
+        if response.lower() != 'yes':
+            print("Not proceeding.")
+            return 0
+        print("Proceeding.")
+
+        run_cert_fix(certs, extra_certs)
+
+        replicate_dogtag_certs(subject_base, ca_subject_dn, certs)
+        install_ipa_certs(subject_base, ca_subject_dn, extra_certs)
+
+        if any(x != 'sslserver' for x in certs) \
+                or any(x[0] is IPACertType.IPARA for x in extra_certs):
+            # we renewed a "shared" certificate, therefore we must
+            # become the renewal master
+            print("Becoming renewal master.")
+            cainstance.CAInstance().set_renewal_master()
+
+        ipautil.run(['ipactl', 'restart'], raiseonerr=True)
+
+        return 0
+
+
+def expired_certs(now):
+    return expired_dogtag_certs(now), expired_ipa_certs(now)
+
+
+def expired_dogtag_certs(now):
+    """
+    Determine which Dogtag certs are expired, or close to expiry.
+
+    Return a list of (cert_id, cert) pairs.
+
+    """
+    certs = []
+    db = NSSDatabase(nssdir=paths.PKI_TOMCAT_ALIAS_DIR)
+
+    for certid, nickname in [
+        ('sslserver', 'Server-Cert cert-pki-ca'),
+        ('subsystem', 'subsystemCert cert-pki-ca'),
+        ('ca_ocsp_signing', 'ocspSigningCert cert-pki-ca'),
+        ('ca_audit_signing', 'auditSigningCert cert-pki-ca'),
+        ('kra_transport', 'transportCert cert-pki-kra'),
+        ('kra_storage', 'storageCert cert-pki-kra'),
+        ('kra_audit_signing', 'auditSigningCert cert-pki-kra'),
+    ]:
+        try:
+            cert = db.get_cert(nickname)
+        except RuntimeError:
+            pass  # unfortunately certdb doesn't give us a better exception
+        else:
+            if cert.not_valid_after <= now:
+                certs.append((certid, cert))
+
+    return certs
+
+
+def expired_ipa_certs(now):
+    """
+    Determine which IPA certs are expired, or close to expiry.
+
+    Return a list of (IPACertType, cert) pairs.
+
+    """
+    certs = []
+
+    # IPA RA
+    cert = x509.load_certificate_from_file(paths.RA_AGENT_PEM)
+    if cert.not_valid_after <= now:
+        certs.append((IPACertType.IPARA, cert))
+
+    # Apache HTTPD
+    cert = x509.load_certificate_from_file(paths.HTTPD_CERT_FILE)
+    if cert.not_valid_after <= now:
+        certs.append((IPACertType.HTTPS, cert))
+
+    # LDAPS
+    ds_dbdir = dsinstance.config_dirname(
+        installutils.realm_to_serverid(api.env.realm))
+    db = NSSDatabase(nssdir=ds_dbdir)
+    cert = db.get_cert('Server-Cert')
+    if cert.not_valid_after <= now:
+        certs.append((IPACertType.LDAPS, cert))
+
+    # KDC
+    cert = x509.load_certificate_from_file(paths.KDC_CERT)
+    if cert.not_valid_after <= now:
+        certs.append((IPACertType.KDC, cert))
+
+    return certs
+
+
+def print_intentions(dogtag_certs, ipa_certs):
+    print("The following certificates will be renewed: ")
+    print()
+
+    for certid, cert in dogtag_certs:
+        print_cert_info("Dogtag", certid, cert)
+
+    for certtype, cert in ipa_certs:
+        print_cert_info("IPA", certtype.value, cert)
+
+
+def print_cert_info(context, desc, cert):
+    print("{} {} certificate:".format(context, desc))
+    print("  Subject: {}".format(DN(cert.subject)))
+    print("  Serial:  {}".format(cert.serial_number))
+    print("  Expires: {}".format(cert.not_valid_after))
+    print()
+
+
+def run_cert_fix(certs, extra_certs):
+    ldapi_path = (
+        paths.SLAPD_INSTANCE_SOCKET_TEMPLATE
+        % '-'.join(api.env.realm.split('.'))
+    )
+    cmd = [
+        'pki-server',
+        'cert-fix',
+        '--ldapi-socket', ldapi_path,
+        '--agent-uid', 'ipara',
+    ]
+    for certid, _cert in certs:
+        cmd.extend(['--cert', certid])
+    for _certtype, cert in extra_certs:
+        cmd.extend(['--extra-cert', str(cert.serial_number)])
+    ipautil.run(cmd, raiseonerr=True)
+
+
+def replicate_dogtag_certs(subject_base, ca_subject_dn, certs):
+    for certid, _oldcert in certs:
+        cert_path = "/etc/pki/pki-tomcat/certs/{}.crt".format(certid)
+        cert = x509.load_certificate_from_file(cert_path)
+        print_cert_info("Renewed Dogtag", certid, cert)
+        replicate_cert(subject_base, ca_subject_dn, cert)
+
+
+def install_ipa_certs(subject_base, ca_subject_dn, certs):
+    """Print details and install renewed IPA certificates."""
+    for certtype, oldcert in certs:
+        cert_path = "/etc/pki/pki-tomcat/certs/{}-renewed.crt" \
+            .format(oldcert.serial_number)
+        cert = x509.load_certificate_from_file(cert_path)
+        print_cert_info("Renewed IPA", certtype.value, cert)
+
+        if certtype is IPACertType.IPARA:
+            shutil.copyfile(cert_path, paths.RA_AGENT_PEM)
+            cainstance.update_people_entry(cert)
+            replicate_cert(subject_base, ca_subject_dn, cert)
+        elif certtype is IPACertType.HTTPS:
+            shutil.copyfile(cert_path, paths.HTTPD_CERT_FILE)
+        elif certtype is IPACertType.LDAPS:
+            ds_dbdir = dsinstance.config_dirname(
+                installutils.realm_to_serverid(api.env.realm))
+            db = NSSDatabase(nssdir=ds_dbdir)
+            db.delete_cert('Server-Cert')
+            db.import_pem_cert('Server-Cert', EMPTY_TRUST_FLAGS, cert_path)
+        elif certtype is IPACertType.KDC:
+            shutil.copyfile(cert_path, paths.KDC_CERT)
+
+
+def replicate_cert(subject_base, ca_subject_dn, cert):
+    nickname = cainstance.get_ca_renewal_nickname(
+        subject_base, ca_subject_dn, DN(cert.subject))
+    if nickname:
+        cainstance.update_ca_renewal_entry(api.Backend.ldap2, nickname, cert)