Add options to write lightweight CA cert or chain to file

Administrators need a way to retrieve the certificate or certificate
chain of an IPA-managed lightweight CA.  Add params to the `ca'
object for carrying the CA certificate and chain (as multiple DER
values).  Add the `--chain' flag for including the chain in the
result (chain is also included with `--all').  Add the
`--certificate-out' option for writing the certificate to a file (or
the chain, if `--chain' was given).

Fixes: https://fedorahosted.org/freeipa/ticket/6178
Reviewed-By: Jan Cholasta <jcholast@redhat.com>
Reviewed-By: Tomas Krizek <tkrizek@redhat.com>

API.txt

@@ -445,10 +445,11 @@ option: Str('version?')
 output: Output('count', type=[<type 'int'>])
 output: Output('results', type=[<type 'list'>, <type 'tuple'>])
 command: ca_add/1
-args: 1,7,3
+args: 1,8,3
 arg: Str('cn', cli_name='name')
 option: Str('addattr*', cli_name='addattr')
 option: Flag('all', autofill=True, cli_name='all', default=False)
+option: Flag('chain', autofill=True, default=False)
 option: Str('description?', cli_name='desc')
 option: DNParam('ipacasubjectdn', cli_name='subject')
 option: Flag('raw', autofill=True, cli_name='raw', default=False)
@@ -519,9 +520,10 @@ output: Entry('result')
 output: Output('summary', type=[<type 'unicode'>, <type 'NoneType'>])
 output: PrimaryKey('value')
 command: ca_show/1
-args: 1,4,3
+args: 1,5,3
 arg: Str('cn', cli_name='name')
 option: Flag('all', autofill=True, cli_name='all', default=False)
+option: Flag('chain', autofill=True, default=False)
 option: Flag('raw', autofill=True, cli_name='raw', default=False)
 option: Flag('rights', autofill=True, default=False)
 option: Str('version?')

VERSION.m4

@@ -73,8 +73,8 @@ define(IPA_DATA_VERSION, 20100614120000)
 #                                                      #
 ########################################################
 define(IPA_API_VERSION_MAJOR, 2)
-define(IPA_API_VERSION_MINOR, 216)
-# Last change: DNS: Support URI resource record type
+define(IPA_API_VERSION_MINOR, 217)
+# Last change: Add options to write lightweight CA cert or chain to file
 
 
 ########################################################

ipaclient/plugins/ca.py

@@ -0,0 +1,53 @@
+#
+# Copyright (C) 2016  FreeIPA Contributors see COPYING for license
+#
+
+import base64
+from ipaclient.frontend import MethodOverride
+from ipalib import util, x509, Str
+from ipalib.plugable import Registry
+from ipalib.text import _
+
+register = Registry()
+
+
+class WithCertOutArgs(MethodOverride):
+
+    takes_options = (
+        Str(
+            'certificate_out?',
+            doc=_('Write certificate (chain if --chain used) to file'),
+            include='cli',
+            cli_metavar='FILE',
+        ),
+    )
+
+    def forward(self, *keys, **options):
+        filename = None
+        if 'certificate_out' in options:
+            filename = options.pop('certificate_out')
+            util.check_writable_file(filename)
+
+        result = super(WithCertOutArgs, self).forward(*keys, **options)
+        if filename:
+            def to_pem(x):
+                return x509.make_pem(x)
+            if options.get('chain', False):
+                ders = result['result']['certificate_chain']
+                data = '\n'.join(to_pem(base64.b64encode(der)) for der in ders)
+            else:
+                data = to_pem(result['result']['certificate'])
+            with open(filename, 'wb') as f:
+                f.write(data)
+
+        return result
+
+
+@register(override=True, no_fail=True)
+class ca_add(WithCertOutArgs):
+    pass
+
+
+@register(override=True, no_fail=True)
+class ca_show(WithCertOutArgs):
+    pass

ipaserver/plugins/ca.py

@@ -2,14 +2,18 @@
 # Copyright (C) 2016  FreeIPA Contributors see COPYING for license
 #
 
-from ipalib import api, errors, output, DNParam, Str
+import base64
+
+import six
+
+from ipalib import api, errors, output, Bytes, DNParam, Flag, Str
 from ipalib.constants import IPA_CA_CN
 from ipalib.plugable import Registry
 from ipaserver.plugins.baseldap import (
     LDAPObject, LDAPSearch, LDAPCreate, LDAPDelete,
     LDAPUpdate, LDAPRetrieve, LDAPQuery, pkey_to_value)
 from ipaserver.plugins.cert import ca_enabled_check
-from ipalib import _, ngettext
+from ipalib import _, ngettext, x509
 
 
 __doc__ = _("""
@@ -100,6 +104,18 @@ class ca(LDAPObject):
             doc=_('Issuer Distinguished Name'),
             flags=['no_create', 'no_update'],
         ),
+        Bytes(
+            'certificate',
+            label=_("Certificate"),
+            doc=_("Base-64 encoded certificate."),
+            flags={'no_create', 'no_update', 'no_search'},
+        ),
+        Bytes(
+            'certificate_chain*',
+            label=_("Certificate chain"),
+            doc=_("X.509 certificate chain"),
+            flags={'no_create', 'no_update', 'no_search'},
+        ),
     )
 
     permission_filter_objectclasses = ['ipaca']
@@ -145,6 +161,21 @@ class ca(LDAPObject):
     }
 
 
+def set_certificate_attrs(entry, options, always_include_cert=True):
+    ca_id = entry['ipacaid'][0]
+    full = options.get('all', False)
+    with api.Backend.ra_lightweight_ca as ca_api:
+        if always_include_cert or full:
+            der = ca_api.read_ca_cert(ca_id)
+            entry['certificate'] = six.text_type(base64.b64encode(der))
+
+        if options.get('chain', False) or full:
+            pkcs7_der = ca_api.read_ca_chain(ca_id)
+            pems = x509.pkcs7_to_pems(pkcs7_der, x509.DER)
+            ders = [x509.normalize_certificate(pem) for pem in pems]
+            entry['certificate_chain'] = ders
+
+
 @register()
 class ca_find(LDAPSearch):
     __doc__ = _("Search for CAs.")
@@ -154,16 +185,32 @@ class ca_find(LDAPSearch):
 
     def execute(self, *keys, **options):
         ca_enabled_check()
-        return super(ca_find, self).execute(*keys, **options)
+        result = super(ca_find, self).execute(*keys, **options)
+        for entry in result['result']:
+            set_certificate_attrs(entry, options, always_include_cert=False)
+        return result
+
+
+_chain_flag = Flag(
+    'chain',
+    default=False,
+    doc=_('Include certificate chain in output'),
+)
 
 
 @register()
 class ca_show(LDAPRetrieve):
     __doc__ = _("Display the properties of a CA.")
 
-    def execute(self, *args, **kwargs):
+    takes_options = LDAPRetrieve.takes_options + (
+        _chain_flag,
+    )
+
+    def execute(self, *keys, **options):
         ca_enabled_check()
-        return super(ca_show, self).execute(*args, **kwargs)
+        result = super(ca_show, self).execute(*keys, **options)
+        set_certificate_attrs(result['result'], options)
+        return result
 
 
 @register()
@@ -171,6 +218,10 @@ class ca_add(LDAPCreate):
     __doc__ = _("Create a CA.")
     msg_summary = _('Created CA "%(value)s"')
 
+    takes_options = LDAPCreate.takes_options + (
+        _chain_flag,
+    )
+
     def pre_callback(self, ldap, dn, entry, entry_attrs, *keys, **options):
         ca_enabled_check()
         if not ldap.can_add(dn[1:]):
@@ -203,6 +254,10 @@ class ca_add(LDAPCreate):
         entry['ipacasubjectdn'] = [resp['dn']]
         return dn
 
+    def post_callback(self, ldap, dn, entry_attrs, *keys, **options):
+        set_certificate_attrs(entry_attrs, options)
+        return dn
+
 
 @register()
 class ca_del(LDAPDelete):

ipaserver/plugins/dogtag.py

@@ -2125,6 +2125,18 @@ class ra_lightweight_ca(RestClient):
         except:
             raise errors.RemoteRetrieveError(reason=_("Response from CA was not valid JSON"))
 
+    def read_ca_cert(self, ca_id):
+        _status, _resp_headers, resp_body = self._ssldo(
+            'GET', '{}/cert'.format(ca_id),
+            headers={'Accept': 'application/pkix-cert'})
+        return resp_body
+
+    def read_ca_chain(self, ca_id):
+        _status, _resp_headers, resp_body = self._ssldo(
+            'GET', '{}/chain'.format(ca_id),
+            headers={'Accept': 'application/pkcs7-mime'})
+        return resp_body
+
     def disable_ca(self, ca_id):
         self._ssldo(
             'POST', ca_id + '/disable',

ipatests/test_xmlrpc/tracker/ca_plugin.py

@@ -8,7 +8,13 @@ import six
 from ipapython.dn import DN
 from ipatests.test_xmlrpc.tracker.base import Tracker
 from ipatests.util import assert_deepequal
-from ipatests.test_xmlrpc.xmlrpc_test import fuzzy_issuer, fuzzy_caid
+from ipatests.test_xmlrpc.xmlrpc_test import (
+    fuzzy_issuer,
+    fuzzy_caid,
+    fuzzy_base64,
+    fuzzy_sequence_of,
+    fuzzy_bytes,
+)
 from ipatests.test_xmlrpc import objectclasses
 
 
@@ -19,12 +25,21 @@ if six.PY3:
 class CATracker(Tracker):
     """Implementation of a Tracker class for CA plugin."""
 
-    retrieve_keys = {
+    ldap_keys = {
         'dn', 'cn', 'ipacaid', 'ipacasubjectdn', 'ipacaissuerdn', 'description'
     }
-    retrieve_all_keys = {'objectclass'} | retrieve_keys
-    create_keys = retrieve_all_keys
-    update_keys = retrieve_keys - {'dn'}
+    cert_keys = {
+        'certificate',
+    }
+    cert_all_keys = {
+        'certificate_chain',
+    }
+    find_keys = ldap_keys
+    find_all_keys = {'objectclass'} | ldap_keys
+    retrieve_keys = ldap_keys | cert_keys
+    retrieve_all_keys = {'objectclass'} | retrieve_keys | cert_all_keys
+    create_keys = {'objectclass'} | retrieve_keys
+    update_keys = ldap_keys - {'dn'}
 
     def __init__(self, name, subject, desc=u"Test generated CA",
                  default_version=None):
@@ -59,6 +74,8 @@ class CATracker(Tracker):
             ipacasubjectdn=[self.ipasubjectdn],
             ipacaissuerdn=[fuzzy_issuer],
             ipacaid=[fuzzy_caid],
+            certificate=fuzzy_base64,
+            certificate_chain=fuzzy_sequence_of(fuzzy_bytes),
             objectclass=objectclasses.ca
         )
         self.exists = True
@@ -102,9 +119,9 @@ class CATracker(Tracker):
     def check_find(self, result, all=False, raw=False):
         """Check the plugin's `find` command result"""
         if all:
-            expected = self.filter_attrs(self.retrieve_all_keys)
+            expected = self.filter_attrs(self.find_all_keys)
         else:
-            expected = self.filter_attrs(self.retrieve_keys)
+            expected = self.filter_attrs(self.find_keys)
 
         assert_deepequal(dict(
             count=1,

ipatests/test_xmlrpc/xmlrpc_test.py

@@ -22,6 +22,7 @@ Base class for all XML-RPC tests
 """
 from __future__ import print_function
 
+import collections
 import datetime
 import inspect
 
@@ -49,6 +50,20 @@ fuzzy_automember_dn = Fuzzy(
     '^cn=%s,cn=automember rebuild membership,cn=tasks,cn=config$' % uuid_re
 )
 
+# base64-encoded value
+fuzzy_base64 = Fuzzy('^[0-9A-Za-z/+]+={0,2}$')
+
+
+def fuzzy_sequence_of(fuzzy):
+    """Construct a Fuzzy for a Sequence of values matching the given Fuzzy."""
+    def test(xs):
+        if not isinstance(xs, collections.Sequence):
+            return False
+        else:
+            return all(fuzzy == x for x in xs)
+
+    return Fuzzy(test=test)
+
 # Matches an automember task finish message
 fuzzy_automember_message = Fuzzy(
     '^Automember rebuild task finished\. Processed \(\d+\) entries\.$'
@@ -109,6 +124,8 @@ fuzzy_dergeneralizedtime = Fuzzy(type=datetime.datetime)
 # match any string
 fuzzy_string = Fuzzy(type=six.string_types)
 
+fuzzy_bytes = Fuzzy(type=bytes)
+
 # case insensitive match of sets
 def fuzzy_set_ci(s):
     return Fuzzy(test=lambda other: set(x.lower() for x in other) == set(y.lower() for y in s))