Enforce CA ACLs in cert-request command

This commit adds CA ACL enforcement to the cert-request command and
uses the pyhbac machinery.

It is planned to implement ACL enforcement in Dogtag in a future
release, and remove certificate issuance privileges and CA ACL
enforcement responsibility from the framework.  See
https://fedorahosted.org/freeipa/ticket/5011 for more information.

Part of: https://fedorahosted.org/freeipa/ticket/57
Part of: https://fedorahosted.org/freeipa/ticket/4559

Reviewed-By: Martin Basti <mbasti@redhat.com>

ipalib/plugins/caacl.py

@@ -2,6 +2,8 @@
 # Copyright (C) 2015  FreeIPA Contributors see COPYING for license
 #
 
+import pyhbac
+
 from ipalib import api, errors, output
 from ipalib import Bool, Str, StrEnum
 from ipalib.plugable import Registry
@@ -10,6 +12,7 @@ from ipalib.plugins.baseldap import (
     LDAPUpdate, LDAPRetrieve, LDAPAddMember, LDAPRemoveMember,
     global_output_params, pkey_to_value)
 from ipalib.plugins.hbacrule import is_all
+from ipalib.plugins.service import normalize_principal, split_any_principal
 from ipalib import _, ngettext
 from ipapython.dn import DN
 
@@ -50,6 +53,79 @@ EXAMPLES:
 register = Registry()
 
 
+def _acl_make_request(principal_type, principal, ca_ref, profile_id):
+    """Construct HBAC request for the given principal, CA and profile"""
+    req = pyhbac.HbacRequest()
+    req.targethost.name = ca_ref
+    req.service.name = profile_id
+    if principal_type == 'user':
+        req.user.name = principal
+    elif principal_type == 'host':
+        req.user.name = principal[:5]  # strip 'host/'
+    elif principal_type == 'service':
+        req.user.name = normalize_principal(principal)
+    groups = []
+    if principal_type == 'user':
+        user_obj = api.Command.user_show(principal)['result']
+        groups = user_obj.get('memberof_group', [])
+        groups += user_obj.get('memberofindirect_group', [])
+    elif principal_type == 'host':
+        service, hostname, realm = split_any_principal(principal)
+        host_obj = api.Command.host_show(hostname)['result']
+        groups = host_obj.get('memberof_hostgroup', [])
+        groups += host_obj.get('memberofindirect_hostgroup', [])
+    req.user.groups = sorted(set(groups))
+    return req
+
+
+def _acl_make_rule(principal_type, obj):
+    """Turn CA ACL object into HBAC rule.
+
+    ``principal_type``
+        String in {'user', 'host', 'service'}
+    """
+    rule = pyhbac.HbacRule(obj['cn'][0])
+    rule.enabled = obj['ipaenabledflag'][0]
+    rule.srchosts.category = {pyhbac.HBAC_CATEGORY_ALL}
+
+    # add CA(s)
+    # Hardcoded until caacl plugin arrives
+    rule.targethosts.category = {pyhbac.HBAC_CATEGORY_ALL}
+    #if 'ipacacategory' in obj and obj['ipacacategory'][0].lower() == 'all':
+    #    rule.targethosts.category = {pyhbac.HBAC_CATEGORY_ALL}
+    #else:
+    #    rule.targethosts.names = obj.get('ipacaaclcaref', [])
+
+    # add profiles
+    if ('ipacertprofilecategory' in obj
+            and obj['ipacertprofilecategory'][0].lower() == 'all'):
+        rule.services.category = {pyhbac.HBAC_CATEGORY_ALL}
+    else:
+        attr = 'ipamembercertprofile_certprofile'
+        rule.services.names = obj.get(attr, [])
+
+    # add principals and principal's groups
+    m = {'user': 'group', 'host': 'hostgroup', 'service': None}
+    category_attr = '{}category'.format(principal_type)
+    if category_attr in obj and obj[category_attr][0].lower() == 'all':
+        rule.users.category = {pyhbac.HBAC_CATEGORY_ALL}
+    else:
+        principal_attr = 'member{}_{}'.format(principal_type, principal_type)
+        rule.users.names = obj.get(principal_attr, [])
+        if m[principal_type] is not None:
+            group_attr = 'member{}_{}'.format(principal_type, m[principal_type])
+            rule.users.groups = obj.get(group_attr, [])
+
+    return rule
+
+
+def acl_evaluate(principal_type, principal, ca_ref, profile_id):
+    req = _acl_make_request(principal_type, principal, ca_ref, profile_id)
+    acls = api.Command.caacl_find()['result']
+    rules = [_acl_make_rule(principal_type, obj) for obj in acls]
+    return req.evaluate(rules) == pyhbac.HBAC_EVAL_ALLOW
+
+
 @register()
 class caacl(LDAPObject):
     """

ipalib/plugins/cert.py

@@ -33,6 +33,7 @@ from ipalib.plugins.virtual import *
 from ipalib.plugins.baseldap import pkey_to_value
 from ipalib.plugins.service import split_any_principal
 from ipalib.plugins.certprofile import validate_profile_id
+import ipalib.plugins.caacl
 import base64
 import traceback
 from ipalib.text import _
@@ -326,6 +327,22 @@ class cert_request(VirtualCommand):
         else:
             principal_type = SERVICE
 
+        principal_type_map = {USER: 'user', HOST: 'host', SERVICE: 'service'}
+        ca = '.'  # top-level CA hardcoded until subca plugin implemented
+        if not ipalib.plugins.caacl.acl_evaluate(
+                principal_type_map[principal_type],
+                principal_string, ca, profile_id):
+            raise errors.ACIError(info=_(
+                    "Principal '%(principal)s' "
+                    "is not permitted to use CA '%(ca)s' "
+                    "with profile '%(profile_id)s' for certificate issuance."
+                ) % dict(
+                    principal=principal_string,
+                    ca=ca or '.',
+                    profile_id=profile_id
+                )
+            )
+
         bind_principal = split_any_principal(getattr(context, 'principal'))
         bind_service, bind_name, bind_realm = bind_principal