xref: /freebsd/crypto/krb5/src/include/krb5/kadm5_hook_plugin.h (revision 7f2fe78b9dd5f51c821d771b63d2e096f6fd49e9)
1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 /*
3  * Copyright (C) 2010 by the Massachusetts Institute of Technology.
4  * All rights reserved.
5  *
6  * Export of this software from the United States of America may
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11  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
12  * distribute this software and its documentation for any purpose and
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14  * notice appear in all copies and that both that copyright notice and
15  * this permission notice appear in supporting documentation, and that
16  * the name of M.I.T. not be used in advertising or publicity pertaining
17  * to distribution of the software without specific, written prior
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24  */
25 
26 #ifndef H_KRB5_KADM5_HOOK_PLUGIN
27 #define H_KRB5_KADM5_HOOK_PLUGIN
28 
29 /**
30  * @file krb5/krb5_kadm5_hook_plugin.h
31  * Provide a plugin interface for kadm5 operations. This interface
32  * permits a plugin to intercept principal modification, creation and
33  * change password operations. Operations run at two stages: a
34  * precommit stage that runs before the operation is committed to the
35  * database and a postcommit operation that runs after the database
36  * is updated; see #kadm5_hook_stage for details on semantics.
37  *
38  * This interface is based on a proposed extension to Heimdal by Russ
39  * Allbery; it is likely that Heimdal will adopt an approach based on
40  * stacked kdb modules rather than this interface. For MIT, writing a
41  * plugin to this interface is significantly easier than stacking kdb
42  * modules. Also, the kadm5 interface is significantly more stable
43  * than the kdb interface, so this approach is more desirable than
44  * stacked kdb modules.
45  *
46  * This interface depends on kadm5/admin.h. As such, the interface
47  * does not provide strong guarantees of ABI stability.
48  *
49  * The kadm5_hook interface currently has only one supported major version,
50  * which is 1.  Major version 1 has a current minor version number of 2.
51  *
52  * kadm5_hook plugins should:
53  * kadm5_hook_<modulename>_initvt, matching the signature:
54  *
55  *   krb5_error_code
56  *   kadm5_hook_modname_initvt(krb5_context context, int maj_ver, int min_ver,
57  *                         krb5_plugin_vtable vtable);
58  *
59  * The initvt function should:
60  *
61  * - Check that the supplied maj_ver number is supported by the module, or
62  *   return KRB5_PLUGIN_VER_NOTSUPP if it is not.
63  *
64  * - Cast the vtable pointer as appropriate for maj_ver:
65  *     maj_ver == 1: Cast to kadm5_hook_vftable_1
66  *
67  * - Initialize the methods of the vtable, stopping as appropriate for the
68  *   supplied min_ver.  Optional methods may be left uninitialized.
69  *
70  * Memory for the vtable is allocated by the caller, not by the module.
71  */
72 
73 #include <krb5/krb5.h>
74 #include <krb5/plugin.h>
75 #include <kadm5/admin.h>
76 
77 /**
78  * Whether the operation is being run before or after the database
79  * update.
80  */
81 enum kadm5_hook_stage {
82     /** In this stage, any plugin failure prevents following plugins from
83      *         running and aborts the operation.*/
84     KADM5_HOOK_STAGE_PRECOMMIT,
85     /** In this stage, plugin failures are logged but otherwise ignored.*/
86     KADM5_HOOK_STAGE_POSTCOMMIT
87 };
88 
89 /** Opaque module data pointer. */
90 typedef struct kadm5_hook_modinfo_st kadm5_hook_modinfo;
91 
92 /**
93  * Interface for the v1 virtual table for the kadm5_hook plugin.
94  * All entry points are optional. The name field must be provided.
95  */
96 typedef struct kadm5_hook_vtable_1_st {
97 
98     /** A text string identifying the plugin for logging messages. */
99     const char *name;
100 
101     /** Initialize a plugin module.
102      * @param modinfo returns newly allocated module info for future
103      * calls.  Cleaned up by the fini() function.
104      */
105     kadm5_ret_t (*init)(krb5_context, kadm5_hook_modinfo **modinfo);
106 
107     /** Clean up a module and free @a modinfo. */
108     void (*fini)(krb5_context, kadm5_hook_modinfo *modinfo);
109 
110     /** Indicates that the password is being changed.
111      * @param stage is an integer from #kadm5_hook_stage enumeration
112      * @param keepold is true if existing keys are being kept.
113      * @param newpass is NULL if the key sare being randomized.
114      */
115     kadm5_ret_t (*chpass)(krb5_context,
116                           kadm5_hook_modinfo *modinfo,
117                           int stage,
118                           krb5_principal, krb5_boolean keepold,
119                           int n_ks_tuple,
120                           krb5_key_salt_tuple *ks_tuple,
121                           const char *newpass);
122 
123     /** Indicate a principal is created. */
124     kadm5_ret_t (*create)(krb5_context,
125                           kadm5_hook_modinfo *,
126                           int stage,
127                           kadm5_principal_ent_t, long mask,
128                           int n_ks_tuple,
129                           krb5_key_salt_tuple *ks_tuple,
130                           const char *password);
131 
132     /** Modify a principal. */
133     kadm5_ret_t (*modify)(krb5_context,
134                           kadm5_hook_modinfo *,
135                           int stage,
136                           kadm5_principal_ent_t, long mask);
137 
138     /** Indicate a principal is deleted. */
139     kadm5_ret_t (*remove)(krb5_context,
140                           kadm5_hook_modinfo *modinfo,
141                           int stage, krb5_principal);
142 
143     /* End of minor version 1. */
144 
145     /** Indicate a principal is renamed. */
146     kadm5_ret_t (*rename)(krb5_context,
147                           kadm5_hook_modinfo *modinfo,
148                           int stage, krb5_principal, krb5_principal);
149 
150     /* End of minor version 2. */
151 
152 } kadm5_hook_vftable_1;
153 
154 #endif /*H_KRB5_KADM5_HOOK_PLUGIN*/
155