1 /*
2  * svc_auth.c, Server-side rpc authenticator interface.
3  *
4  * Copyright (c) 2010, Oracle America, Inc.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions are
8  * met:
9  *
10  *     * Redistributions of source code must retain the above copyright
11  *       notice, this list of conditions and the following disclaimer.
12  *     * Redistributions in binary form must reproduce the above
13  *       copyright notice, this list of conditions and the following
14  *       disclaimer in the documentation and/or other materials
15  *       provided with the distribution.
16  *     * Neither the name of the "Oracle America, Inc." nor the names of its
17  *       contributors may be used to endorse or promote products derived
18  *       from this software without specific prior written permission.
19  *
20  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
25  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <rpc/rpc.h>
35 #include <rpc/svc.h>
36 #include <rpc/svc_auth.h>
37 #include <shlib-compat.h>
38 
39 /*
40  * svcauthsw is the bdevsw of server side authentication.
41  *
42  * Server side authenticators are called from authenticate by
43  * using the client auth struct flavor field to index into svcauthsw.
44  * The server auth flavors must implement a routine that looks
45  * like:
46  *
47  *      enum auth_stat
48  *      flavorx_auth(rqst, msg)
49  *              register struct svc_req *rqst;
50  *              register struct rpc_msg *msg;
51  *
52  */
53 
54 static enum auth_stat _svcauth_null (struct svc_req *, struct rpc_msg *);
55 				/* no authentication */
56 extern enum auth_stat _svcauth_unix (struct svc_req *, struct rpc_msg *);
57 				/* unix style (uid, gids) */
58 extern enum auth_stat _svcauth_short (struct svc_req *, struct rpc_msg *);
59 				/* short hand unix style */
60 extern enum auth_stat _svcauth_des (struct svc_req *, struct rpc_msg *);
61 				/* des style */
62 
63 static const struct
64   {
65     enum auth_stat (*authenticator) (struct svc_req *, struct rpc_msg *);
66   }
67 svcauthsw[] =
68 {
69   { _svcauth_null },		/* AUTH_NULL */
70   { _svcauth_unix },		/* AUTH_UNIX */
71   { _svcauth_short },		/* AUTH_SHORT */
72   { _svcauth_des }		/* AUTH_DES */
73 };
74 #define	AUTH_MAX	3	/* HIGHEST AUTH NUMBER */
75 
76 
77 /*
78  * The call rpc message, msg has been obtained from the wire.  The msg contains
79  * the raw form of credentials and verifiers.  authenticate returns AUTH_OK
80  * if the msg is successfully authenticated.  If AUTH_OK then the routine also
81  * does the following things:
82  * set rqst->rq_xprt->verf to the appropriate response verifier;
83  * sets rqst->rq_client_cred to the "cooked" form of the credentials.
84  *
85  * NB: rqst->rq_cxprt->verf must be pre-allocated;
86  * its length is set appropriately.
87  *
88  * The caller still owns and is responsible for msg->u.cmb.cred and
89  * msg->u.cmb.verf.  The authentication system retains ownership of
90  * rqst->rq_client_cred, the cooked credentials.
91  *
92  * There is an assumption that any flavour less than AUTH_NULL is
93  * invalid.
94  */
95 enum auth_stat
_authenticate(register struct svc_req * rqst,struct rpc_msg * msg)96 _authenticate (register struct svc_req *rqst, struct rpc_msg *msg)
97 {
98   register int cred_flavor;
99 
100   rqst->rq_cred = msg->rm_call.cb_cred;
101   rqst->rq_xprt->xp_verf.oa_flavor = _null_auth.oa_flavor;
102   rqst->rq_xprt->xp_verf.oa_length = 0;
103   cred_flavor = rqst->rq_cred.oa_flavor;
104   if ((cred_flavor <= AUTH_MAX) && (cred_flavor >= AUTH_NULL))
105     return (*(svcauthsw[cred_flavor].authenticator)) (rqst, msg);
106 
107   return AUTH_REJECTEDCRED;
108 }
libc_hidden_nolink_sunrpc(_authenticate,GLIBC_2_1)109 libc_hidden_nolink_sunrpc (_authenticate, GLIBC_2_1)
110 
111 static enum auth_stat
112 _svcauth_null (struct svc_req *rqst, struct rpc_msg *msg)
113 {
114   return AUTH_OK;
115 }
116