xref: /freebsd/crypto/krb5/src/include/krb5/kdcauthdata_plugin.h (revision 7f2fe78b9dd5f51c821d771b63d2e096f6fd49e9)
1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 /*
3  * Copyright (C) 2014 by the Massachusetts Institute of Technology.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * * Redistributions of source code must retain the above copyright
11  *   notice, this list of conditions and the following disclaimer.
12  *
13  * * Redistributions in binary form must reproduce the above copyright
14  *   notice, this list of conditions and the following disclaimer in
15  *   the documentation and/or other materials provided with the
16  *   distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22  * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
23  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
27  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
29  * OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * This interface is not yet public and may change without honoring the
34  * pluggable interface version system.  The header file is deliberately not
35  * installed by "make install".
36  *
37  * This interface references kdb.h, which is not stable.  A module which
38  * references fields of krb5_db_entry, invokes libkdb5 functions, or uses the
39  * flags argument may not be future-proof even if this interface becomes
40  * public.
41  *
42  * Expecting modules to hand-modify enc_tkt_reply->authorization_data is
43  * cumbersome for the module, and doesn't work if the module uses a different
44  * allocator from the krb5 tree.  A libkrb5 API to add an authdata value to a
45  * list would improve this situation.
46  */
47 
48 /*
49  * Declarations for kdcauthdata plugin module implementors.
50  *
51  * The kdcauthdata interface has a single supported major version, which is 1.
52  * Major version 1 has a current minor version of 1.  kdcauthdata modules
53  * should define a function named kdcauthdata_<modulename>_initvt, matching the
54  * signature:
55  *
56  *   krb5_error_code
57  *   kdcauthdata_modname_initvt(krb5_context context, int maj_ver, int min_ver,
58  *                              krb5_plugin_vtable vtable);
59  *
60  * The initvt function should:
61  *
62  * - Check that the supplied maj_ver number is supported by the module, or
63  *   return KRB5_PLUGIN_VER_NOTSUPP if it is not.
64  *
65  * - Cast the vtable pointer as appropriate for the interface and maj_ver:
66  *     maj_ver == 1: Cast to krb5_kdcauthdata_vtable
67  *
68  * - Initialize the methods of the vtable, stopping as appropriate for the
69  *   supplied min_ver.  Optional methods may be left uninitialized.
70  *
71  * Memory for the vtable is allocated by the caller, not by the module.
72  */
73 
74 #ifndef KRB5_KDCAUTHDATA_PLUGIN_H
75 #define KRB5_KDCAUTHDATA_PLUGIN_H
76 
77 #include <krb5/krb5.h>
78 #include <krb5/plugin.h>
79 #include <kdb.h>
80 
81 /* Abstract type for module data. */
82 typedef struct krb5_kdcauthdata_moddata_st *krb5_kdcauthdata_moddata;
83 
84 /* Optional: module initialization function.  If this function returns an
85  * error, the KDC will log the failure and ignore the module. */
86 typedef krb5_error_code
87 (*krb5_kdcauthdata_init_fn)(krb5_context context,
88                             krb5_kdcauthdata_moddata *moddata_out);
89 
90 /* Optional: module cleanup function. */
91 typedef void
92 (*krb5_kdcauthdata_fini_fn)(krb5_context context,
93                             krb5_kdcauthdata_moddata moddata);
94 
95 /*
96  * Mandatory: authorization data handling function.
97  *
98  * All values should be considered input-only, except that the method can
99  * modify enc_tkt_reply->authorization_data to add authdata values.  This field
100  * is a null-terminated list of allocated pointers; the plugin method must
101  * reallocate it to make room for any added authdata values.
102  *
103  * If this function returns an error, the AS or TGS request will be rejected.
104  */
105 typedef krb5_error_code
106 (*krb5_kdcauthdata_handle_fn)(krb5_context context,
107                               krb5_kdcauthdata_moddata moddata,
108                               unsigned int flags,
109                               krb5_db_entry *client, krb5_db_entry *server,
110                               krb5_db_entry *header_server,
111                               krb5_keyblock *client_key,
112                               krb5_keyblock *server_key,
113                               krb5_keyblock *header_key,
114                               krb5_data *req_pkt, krb5_kdc_req *req,
115                               krb5_const_principal for_user_princ,
116                               krb5_enc_tkt_part *enc_tkt_req,
117                               krb5_enc_tkt_part *enc_tkt_reply);
118 
119 typedef struct krb5_kdcauthdata_vtable_st {
120     /* Mandatory: name of module. */
121     const char *name;
122 
123     krb5_kdcauthdata_init_fn init;
124     krb5_kdcauthdata_fini_fn fini;
125     krb5_kdcauthdata_handle_fn handle;
126     /* Minor 1 ends here. */
127 } *krb5_kdcauthdata_vtable;
128 
129 #endif /* KRB5_KDCAUTHDATA_PLUGIN_H */
130