1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 /* include/krb5/kdcpolicy_plugin.h - KDC policy plugin interface */
3 /*
4  * Copyright (C) 2017 by Red Hat, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * * Redistributions of source code must retain the above copyright
12  *   notice, this list of conditions and the following disclaimer.
13  *
14  * * Redistributions in binary form must reproduce the above copyright
15  *   notice, this list of conditions and the following disclaimer in
16  *   the documentation and/or other materials provided with the
17  *   distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
22  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
23  * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
24  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
25  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
26  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
28  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
30  * OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * Declarations for kdcpolicy plugin module implementors.
35  *
36  * The kdcpolicy pluggable interface currently has only one supported major
37  * version, which is 1.  Major version 1 has a current minor version number of
38  * 1.
39  *
40  * kdcpolicy plugin modules should define a function named
41  * kdcpolicy_<modulename>_initvt, matching the signature:
42  *
43  *   krb5_error_code
44  *   kdcpolicy_modname_initvt(krb5_context context, int maj_ver, int min_ver,
45  *                            krb5_plugin_vtable vtable);
46  *
47  * The initvt function should:
48  *
49  * - Check that the supplied maj_ver number is supported by the module, or
50  *   return KRB5_PLUGIN_VER_NOTSUPP if it is not.
51  *
52  * - Cast the vtable pointer as appropriate for maj_ver:
53  *   maj_ver == 1: Cast to krb5_kdcpolicy_vtable
54  *
55  * - Initialize the methods of the vtable, stopping as appropriate for the
56  *   supplied min_ver.  Optional methods may be left uninitialized.
57  *
58  * Memory for the vtable is allocated by the caller, not by the module.
59  */
60 
61 #ifndef KRB5_POLICY_PLUGIN_H
62 #define KRB5_POLICY_PLUGIN_H
63 
64 #include <krb5/krb5.h>
65 
66 /* Abstract module datatype. */
67 typedef struct krb5_kdcpolicy_moddata_st *krb5_kdcpolicy_moddata;
68 
69 /* A module can optionally include kdb.h to inspect principal entries when
70  * authorizing requests. */
71 struct _krb5_db_entry_new;
72 
73 /*
74  * Optional: Initialize module data.  Return 0 on success,
75  * KRB5_PLUGIN_NO_HANDLE if the module is inoperable (due to configuration, for
76  * example), and any other error code to abort KDC startup.  Optionally set
77  * *data_out to a module data object to be passed to future calls.
78  */
79 typedef krb5_error_code
80 (*krb5_kdcpolicy_init_fn)(krb5_context context,
81                           krb5_kdcpolicy_moddata *data_out);
82 
83 /* Optional: Clean up module data. */
84 typedef krb5_error_code
85 (*krb5_kdcpolicy_fini_fn)(krb5_context context,
86                           krb5_kdcpolicy_moddata moddata);
87 
88 /*
89  * Optional: return an error code and set status to an appropriate string
90  * literal to deny an AS request; otherwise return 0.  lifetime_out, if set,
91  * restricts the ticket lifetime.  renew_lifetime_out, if set, restricts the
92  * ticket renewable lifetime.
93  */
94 typedef krb5_error_code
95 (*krb5_kdcpolicy_check_as_fn)(krb5_context context,
96                               krb5_kdcpolicy_moddata moddata,
97                               const krb5_kdc_req *request,
98                               const struct _krb5_db_entry_new *client,
99                               const struct _krb5_db_entry_new *server,
100                               const char *const *auth_indicators,
101                               const char **status, krb5_deltat *lifetime_out,
102                               krb5_deltat *renew_lifetime_out);
103 
104 /*
105  * Optional: return an error code and set status to an appropriate string
106  * literal to deny a TGS request; otherwise return 0.  lifetime_out, if set,
107  * restricts the ticket lifetime.  renew_lifetime_out, if set, restricts the
108  * ticket renewable lifetime.
109  */
110 typedef krb5_error_code
111 (*krb5_kdcpolicy_check_tgs_fn)(krb5_context context,
112                                krb5_kdcpolicy_moddata moddata,
113                                const krb5_kdc_req *request,
114                                const struct _krb5_db_entry_new *server,
115                                const krb5_ticket *ticket,
116                                const char *const *auth_indicators,
117                                const char **status, krb5_deltat *lifetime_out,
118                                krb5_deltat *renew_lifetime_out);
119 
120 typedef struct krb5_kdcpolicy_vtable_st {
121     const char *name;
122     krb5_kdcpolicy_init_fn init;
123     krb5_kdcpolicy_fini_fn fini;
124     krb5_kdcpolicy_check_as_fn check_as;
125     krb5_kdcpolicy_check_tgs_fn check_tgs;
126 } *krb5_kdcpolicy_vtable;
127 
128 #endif /* KRB5_POLICY_PLUGIN_H */
129