path: root/ipaserver/install/ca.py

#
# Copyright (C) 2015  FreeIPA Contributors see COPYING for license
#

"""
CA installer module
"""

from __future__ import print_function

import enum
import os.path

import six

from ipalib.install import certstore
from ipalib.install.service import enroll_only, master_install_only, replica_install_only
from ipapython.install import typing
from ipapython.install.core import knob
from ipaserver.install import (cainstance,
                               custodiainstance,
                               dsinstance,
                               bindinstance)
from ipapython import ipautil, certdb
from ipapython.admintool import ScriptError
from ipaplatform import services
from ipaplatform.paths import paths
from ipaserver.install import installutils, certs
from ipaserver.install.replication import replica_conn_check
from ipalib import api, x509
from ipapython.dn import DN
from ipapython.ipa_log_manager import root_logger

from . import conncheck, dogtag

if six.PY3:
    unicode = str

VALID_SUBJECT_ATTRS = ['st', 'o', 'ou', 'dnqualifier', 'c',
                       'serialnumber', 'l', 'title', 'sn', 'givenname',
                       'initials', 'generationqualifier', 'dc', 'mail',
                       'uid', 'postaladdress', 'postalcode', 'postofficebox',
                       'houseidentifier', 'e', 'street', 'pseudonym',
                       'incorporationlocality', 'incorporationstate',
                       'incorporationcountry', 'businesscategory']

external_cert_file = None
external_ca_file = None


def install_check(standalone, replica_config, options):
    global external_cert_file
    global external_ca_file

    if replica_config is not None and not replica_config.setup_ca:
        return

    realm_name = options.realm_name
    host_name = options.host_name
    subject_base = options.subject

    if replica_config is not None:
        if standalone and api.env.ra_plugin == 'selfsign':
            raise ScriptError('A selfsign CA can not be added')

        cafile = os.path.join(replica_config.dir, 'cacert.p12')
        if not options.promote and not ipautil.file_exists(cafile):
            raise ScriptError('CA cannot be installed in CA-less setup.')

        if standalone and not options.skip_conncheck:
            principal = options.principal
            replica_conn_check(
                replica_config.ca_host_name, host_name, realm_name, True,
                replica_config.ca_ds_port, options.admin_password,
                principal=principal, ca_cert_file=options.ca_cert_file)

        if options.skip_schema_check:
            root_logger.info("Skipping CA DS schema check")
        else:
            cainstance.replica_ca_install_check(replica_config, options.promote)

        return

    if standalone:
        if api.Command.ca_is_enabled()['result']:
            raise ScriptError(
                "One or more CA masters are already present in IPA realm "
                "'%s'.\nIf you wish to replicate CA to this host, please "
                "re-run 'ipa-ca-install'\nwith a replica file generated on "
                "an existing CA master as argument." % realm_name
            )

    if options.external_cert_files:
        if not cainstance.is_step_one_done():
            # This can happen if someone passes external_ca_file without
            # already having done the first stage of the CA install.
            raise ScriptError(
                  "CA is not installed yet. To install with an external CA "
                  "is a two-stage process.\nFirst run the installer with "
                  "--external-ca.")

        external_cert_file, external_ca_file = installutils.load_external_cert(
            options.external_cert_files, options.subject)
    elif options.external_ca:
        if cainstance.is_step_one_done():
            raise ScriptError(
                "CA is already installed.\nRun the installer with "
                "--external-cert-file.")
        if ipautil.file_exists(paths.ROOT_IPA_CSR):
            raise ScriptError(
                "CA CSR file %s already exists.\nIn order to continue "
                "remove the file and run the installer again." %
                paths.ROOT_IPA_CSR)

    if not options.external_cert_files:
        if not cainstance.check_port():
            print("IPA requires port 8443 for PKI but it is currently in use.")
            raise ScriptError("Aborting installation")

    if standalone:
        dirname = dsinstance.config_dirname(
            installutils.realm_to_serverid(realm_name))
        cadb = certs.CertDB(realm_name, subject_base=subject_base)
        dsdb = certs.CertDB(realm_name, nssdir=dirname, subject_base=subject_base)

        for db in (cadb, dsdb):
            for nickname, _trust_flags in db.list_certs():
                if nickname in (certdb.get_ca_nickname(realm_name),
                                'ipaCert'):
                    raise ScriptError(
                        "Certificate with nickname %s is present in %s, "
                        "cannot continue." % (nickname, db.secdir))

                cert = db.get_cert_from_db(nickname)
                if not cert:
                    continue
                subject = DN(x509.load_certificate(cert).subject)
                if subject in (DN('CN=Certificate Authority', subject_base),
                               DN('CN=IPA RA', subject_base)):
                    raise ScriptError(
                        "Certificate with subject %s is present in %s, "
                        "cannot continue." % (subject, db.secdir))


def install(standalone, replica_config, options):
    install_step_0(standalone, replica_config, options)
    install_step_1(standalone, replica_config, options)


def install_step_0(standalone, replica_config, options):
    realm_name = options.realm_name
    dm_password = options.dm_password
    host_name = options.host_name

    if replica_config is None:
        subject_base = options.subject

        ca_signing_algorithm = options.ca_signing_algorithm
        if options.external_ca:
            ca_type = options.external_ca_type
            csr_file = paths.ROOT_IPA_CSR
        else:
            ca_type = None
            csr_file = None
        if options.external_cert_files:
            cert_file = external_cert_file.name
            cert_chain_file = external_ca_file.name
        else:
            cert_file = None
            cert_chain_file = None

        pkcs12_info = None
        master_host = None
        master_replication_port = None
        ra_p12 = None
        ra_only = False
        promote = False
    else:
        cafile = os.path.join(replica_config.dir, 'cacert.p12')
        if options.promote:
            custodia = custodiainstance.CustodiaInstance(
                replica_config.host_name,
                replica_config.realm_name)
            custodia.get_ca_keys(
                replica_config.ca_host_name,
                cafile,
                replica_config.dirman_password)

        subject_base = replica_config.subject_base

        ca_signing_algorithm = None
        ca_type = None
        csr_file = None
        cert_file = None
        cert_chain_file = None

        pkcs12_info = (cafile,)
        master_host = replica_config.ca_host_name
        master_replication_port = replica_config.ca_ds_port
        ra_p12 = os.path.join(replica_config.dir, 'ra.p12')
        ra_only = not replica_config.setup_ca
        promote = options.promote

    ca = cainstance.CAInstance(realm_name, certs.NSS_DIR,
                               host_name=host_name)
    ca.configure_instance(host_name, dm_password, dm_password,
                          subject_base=subject_base,
                          ca_signing_algorithm=ca_signing_algorithm,
                          ca_type=ca_type,
                          csr_file=csr_file,
                          cert_file=cert_file,
                          cert_chain_file=cert_chain_file,
                          pkcs12_info=pkcs12_info,
                          master_host=master_host,
                          master_replication_port=master_replication_port,
                          ra_p12=ra_p12,
                          ra_only=ra_only,
                          promote=promote,
                          use_ldaps=standalone)


def install_step_1(standalone, replica_config, options):
    if replica_config is not None and not replica_config.setup_ca:
        return

    realm_name = options.realm_name
    host_name = options.host_name
    subject_base = options.subject

    basedn = ipautil.realm_to_suffix(realm_name)

    ca = cainstance.CAInstance(realm_name, certs.NSS_DIR, host_name=host_name)

    ca.stop('pki-tomcat')

    # This is done within stopped_service context, which restarts CA
    ca.enable_client_auth_to_db(paths.CA_CS_CFG_PATH)

    # Lightweight CA key retrieval is configured in step 1 instead
    # of CAInstance.configure_instance (which is invoked from step
    # 0) because kadmin_addprinc fails until krb5.conf is installed
    # by krb.create_instance.
    #
    ca.setup_lightweight_ca_key_retrieval()

    serverid = installutils.realm_to_serverid(realm_name)

    if standalone and replica_config is None:
        dirname = dsinstance.config_dirname(serverid)

        # Store the new IPA CA cert chain in DS NSS database and LDAP
        cadb = certs.CertDB(realm_name, subject_base=subject_base)
        dsdb = certs.CertDB(realm_name, nssdir=dirname, subject_base=subject_base)
        trust_flags = dict(reversed(cadb.list_certs()))
        trust_chain = cadb.find_root_cert('ipaCert')[:-1]
        for nickname in trust_chain[:-1]:
            cert = cadb.get_cert_from_db(nickname, pem=False)
            dsdb.add_cert(cert, nickname, trust_flags[nickname])
            certstore.put_ca_cert_nss(api.Backend.ldap2, api.env.basedn,
                                      cert, nickname, trust_flags[nickname])

        nickname = trust_chain[-1]
        cert = cadb.get_cert_from_db(nickname, pem=False)
        dsdb.add_cert(cert, nickname, trust_flags[nickname])
        certstore.put_ca_cert_nss(api.Backend.ldap2, api.env.basedn,
                                  cert, nickname, trust_flags[nickname],
                                  config_ipa=True, config_compat=True)

        # Store DS CA cert in Dogtag NSS database
        dogtagdb = certs.CertDB(realm_name, nssdir=paths.PKI_TOMCAT_ALIAS_DIR)
        trust_flags = dict(reversed(dsdb.list_certs()))
        server_certs = dsdb.find_server_certs()
        trust_chain = dsdb.find_root_cert(server_certs[0][0])[:-1]
        nickname = trust_chain[-1]
        cert = dsdb.get_cert_from_db(nickname)
        dogtagdb.add_cert(cert, nickname, trust_flags[nickname])

    installutils.restart_dirsrv()

    ca.start('pki-tomcat')

    if standalone or replica_config is not None:
        # We need to restart apache as we drop a new config file in there
        services.knownservices.httpd.restart(capture_output=True)

    if standalone:
        # Install CA DNS records
        if bindinstance.dns_container_exists(basedn):
            bind = bindinstance.BindInstance()
            bind.update_system_records()


def uninstall():
    ca_instance = cainstance.CAInstance(
        api.env.realm, certs.NSS_DIR)
    ca_instance.stop_tracking_certificates()
    if ca_instance.is_configured():
        ca_instance.uninstall()


class ExternalCAType(enum.Enum):
    GENERIC = 'generic'
    MS_CS = 'ms-cs'


class CASigningAlgorithm(enum.Enum):
    SHA1_WITH_RSA = 'SHA1withRSA'
    SHA_256_WITH_RSA = 'SHA256withRSA'
    SHA_512_WITH_RSA = 'SHA512withRSA'


class CAInstallInterface(dogtag.DogtagInstallInterface,
                         conncheck.ConnCheckInterface):
    """
    Interface of the CA installer

    Knobs defined here will be available in:
    * ipa-server-install
    * ipa-replica-prepare
    * ipa-replica-install
    * ipa-ca-install
    """

    principal = knob(
        bases=conncheck.ConnCheckInterface.principal,
        description="User allowed to manage replicas",
        cli_names=(
            list(conncheck.ConnCheckInterface.principal.cli_names) + ['-P']),
    )
    principal = enroll_only(principal)
    principal = replica_install_only(principal)

    admin_password = knob(
        bases=conncheck.ConnCheckInterface.admin_password,
        description="Admin user Kerberos password used for connection check",
        cli_names=(
            list(conncheck.ConnCheckInterface.admin_password.cli_names) +
            ['-w']),
    )
    admin_password = enroll_only(admin_password)
    admin_password = replica_install_only(admin_password)

    external_ca = knob(
        None,
        description=("Generate a CSR for the IPA CA certificate to be signed "
                     "by an external CA"),
    )
    external_ca = master_install_only(external_ca)

    external_ca_type = knob(
        ExternalCAType, None,
        description="Type of the external CA",
    )
    external_ca_type = master_install_only(external_ca_type)

    external_cert_files = knob(
        # pylint: disable=invalid-sequence-index
        typing.List[str], None,
        description=("File containing the IPA CA certificate and the external "
                     "CA certificate chain"),
        cli_names='--external-cert-file',
        cli_deprecated_names=['--external_cert_file', '--external_ca_file'],
        cli_metavar='FILE',
    )
    external_cert_files = master_install_only(external_cert_files)

    @external_cert_files.validator
    def external_cert_files(self, value):
        if any(not os.path.isabs(path) for path in value):
            raise ValueError("must use an absolute path")

    subject = knob(
        str, None,
        description="The certificate subject base (default O=<realm-name>)",
    )
    subject = master_install_only(subject)

    @subject.validator
    def subject(self, value):
        v = unicode(value, 'utf-8')
        if any(ord(c) < 0x20 for c in v):
            raise ValueError("must not contain control characters")
        if '&' in v:
            raise ValueError("must not contain an ampersand (\"&\")")
        try:
            dn = DN(v)
            for rdn in dn:
                if rdn.attr.lower() not in VALID_SUBJECT_ATTRS:
                    raise ValueError("invalid attribute: \"%s\"" % rdn.attr)
        except ValueError as e:
            raise ValueError("invalid subject base format: %s" % e)

    ca_signing_algorithm = knob(
        CASigningAlgorithm, None,
        description="Signing algorithm of the IPA CA certificate",
    )
    ca_signing_algorithm = master_install_only(ca_signing_algorithm)

    skip_schema_check = knob(
        None,
        description="skip check for updated CA DS schema on the remote master",
    )
    skip_schema_check = enroll_only(skip_schema_check)
    skip_schema_check = replica_install_only(skip_schema_check)