1/*	$NetBSD: svc_auth.c,v 1.12 2000/07/06 03:10:35 christos Exp $	*/
2
3/*-
4 * SPDX-License-Identifier: BSD-3-Clause
5 *
6 * Copyright (c) 2009, Sun Microsystems, Inc.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions are met:
11 * - Redistributions of source code must retain the above copyright notice,
12 *   this list of conditions and the following disclaimer.
13 * - Redistributions in binary form must reproduce the above copyright notice,
14 *   this list of conditions and the following disclaimer in the documentation
15 *   and/or other materials provided with the distribution.
16 * - Neither the name of Sun Microsystems, 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 "AS IS"
21 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
24 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32/*
33 * Copyright (c) 1986-1991 by Sun Microsystems Inc.
34 */
35
36/*
37 * svc_auth.c, Server-side rpc authenticator interface.
38 *
39 */
40
41#include "namespace.h"
42#include "reentrant.h"
43#include <sys/types.h>
44#include <rpc/rpc.h>
45#include <stdlib.h>
46#include "un-namespace.h"
47#include "mt_misc.h"
48
49/*
50 * svcauthsw is the bdevsw of server side authentication.
51 *
52 * Server side authenticators are called from authenticate by
53 * using the client auth struct flavor field to index into svcauthsw.
54 * The server auth flavors must implement a routine that looks
55 * like:
56 *
57 *	enum auth_stat
58 *	flavorx_auth(rqst, msg)
59 *		struct svc_req *rqst;
60 *		struct rpc_msg *msg;
61 *
62 */
63
64/* declarations to allow servers to specify new authentication flavors */
65struct authsvc {
66	int	flavor;
67	enum	auth_stat (*handler)(struct svc_req *, struct rpc_msg *);
68	struct	authsvc	  *next;
69};
70static struct authsvc *Auths = NULL;
71
72struct svc_auth_ops svc_auth_null_ops;
73
74/*
75 * The call rpc message, msg has been obtained from the wire.  The msg contains
76 * the raw form of credentials and verifiers.  authenticate returns AUTH_OK
77 * if the msg is successfully authenticated.  If AUTH_OK then the routine also
78 * does the following things:
79 * set rqst->rq_xprt->verf to the appropriate response verifier;
80 * sets rqst->rq_client_cred to the "cooked" form of the credentials.
81 *
82 * NB: rqst->rq_cxprt->verf must be pre-allocated;
83 * its length is set appropriately.
84 *
85 * The caller still owns and is responsible for msg->u.cmb.cred and
86 * msg->u.cmb.verf.  The authentication system retains ownership of
87 * rqst->rq_client_cred, the cooked credentials.
88 *
89 * There is an assumption that any flavour less than AUTH_NULL is
90 * invalid.
91 */
92enum auth_stat
93_authenticate(struct svc_req *rqst, struct rpc_msg *msg)
94{
95	int cred_flavor;
96	struct authsvc *asp;
97	enum auth_stat dummy;
98
99/* VARIABLES PROTECTED BY authsvc_lock: asp, Auths */
100
101	rqst->rq_cred = msg->rm_call.cb_cred;
102	SVC_AUTH(rqst->rq_xprt).svc_ah_ops = &svc_auth_null_ops;
103	SVC_AUTH(rqst->rq_xprt).svc_ah_private = NULL;
104	rqst->rq_xprt->xp_verf.oa_flavor = _null_auth.oa_flavor;
105	rqst->rq_xprt->xp_verf.oa_length = 0;
106	cred_flavor = rqst->rq_cred.oa_flavor;
107	switch (cred_flavor) {
108	case AUTH_NULL:
109		dummy = _svcauth_null(rqst, msg);
110		return (dummy);
111	case AUTH_SYS:
112		dummy = _svcauth_unix(rqst, msg);
113		return (dummy);
114	case AUTH_SHORT:
115		dummy = _svcauth_short(rqst, msg);
116		return (dummy);
117#ifdef DES_BUILTIN
118	case AUTH_DES:
119		dummy = _svcauth_des(rqst, msg);
120		return (dummy);
121#endif
122	default:
123		break;
124	}
125
126	/* flavor doesn't match any of the builtin types, so try new ones */
127	mutex_lock(&authsvc_lock);
128	for (asp = Auths; asp; asp = asp->next) {
129		if (asp->flavor == cred_flavor) {
130			enum auth_stat as;
131
132			as = (*asp->handler)(rqst, msg);
133			mutex_unlock(&authsvc_lock);
134			return (as);
135		}
136	}
137	mutex_unlock(&authsvc_lock);
138
139	return (AUTH_REJECTEDCRED);
140}
141
142/*
143 * A set of null auth methods used by any authentication protocols
144 * that don't need to inspect or modify the message body.
145 */
146static bool_t
147svcauth_null_wrap(SVCAUTH *auth, XDR *xdrs, xdrproc_t xdr_func, caddr_t xdr_ptr)
148{
149
150	return (xdr_func(xdrs, xdr_ptr));
151}
152
153struct svc_auth_ops svc_auth_null_ops = {
154	svcauth_null_wrap,
155	svcauth_null_wrap,
156};
157
158/*ARGSUSED*/
159enum auth_stat
160_svcauth_null(struct svc_req *rqst, struct rpc_msg *msg)
161{
162	return (AUTH_OK);
163}
164
165/*
166 *  Allow the rpc service to register new authentication types that it is
167 *  prepared to handle.  When an authentication flavor is registered,
168 *  the flavor is checked against already registered values.  If not
169 *  registered, then a new Auths entry is added on the list.
170 *
171 *  There is no provision to delete a registration once registered.
172 *
173 *  This routine returns:
174 *	 0 if registration successful
175 *	 1 if flavor already registered
176 *	-1 if can't register (errno set)
177 */
178
179int
180svc_auth_reg(int cred_flavor,
181    enum auth_stat (*handler)(struct svc_req *, struct rpc_msg *))
182{
183	struct authsvc *asp;
184
185	switch (cred_flavor) {
186	    case AUTH_NULL:
187	    case AUTH_SYS:
188	    case AUTH_SHORT:
189#ifdef DES_BUILTIN
190	    case AUTH_DES:
191#endif
192		/* already registered */
193		return (1);
194
195	    default:
196		mutex_lock(&authsvc_lock);
197		for (asp = Auths; asp; asp = asp->next) {
198			if (asp->flavor == cred_flavor) {
199				/* already registered */
200				mutex_unlock(&authsvc_lock);
201				return (1);
202			}
203		}
204
205		/* this is a new one, so go ahead and register it */
206		asp = mem_alloc(sizeof (*asp));
207		if (asp == NULL) {
208			mutex_unlock(&authsvc_lock);
209			return (-1);
210		}
211		asp->flavor = cred_flavor;
212		asp->handler = handler;
213		asp->next = Auths;
214		Auths = asp;
215		mutex_unlock(&authsvc_lock);
216		break;
217	}
218	return (0);
219}
220