xref: /netbsd-src/lib/libc/rpc/svc_auth.c (revision 85f5e301f5b0e5c7695c7222d16769f8f55f6aeb)
1 /*	$NetBSD: svc_auth.c,v 1.19 2024/01/23 17:24:38 christos Exp $	*/
2 
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  * Copyright (c) 1986-1991 by Sun Microsystems Inc.
35  */
36 
37 /* #ident	"@(#)svc_auth.c	1.16	94/04/24 SMI" */
38 
39 #include <sys/cdefs.h>
40 #if defined(LIBC_SCCS) && !defined(lint)
41 #if 0
42 static char sccsid[] = "@(#)svc_auth.c 1.26 89/02/07 Copyr 1984 Sun Micro";
43 #else
44 __RCSID("$NetBSD: svc_auth.c,v 1.19 2024/01/23 17:24:38 christos Exp $");
45 #endif
46 #endif
47 
48 /*
49  * svc_auth.c, Server-side rpc authenticator interface.
50  *
51  */
52 
53 #include "namespace.h"
54 #include "reentrant.h"
55 #include <sys/types.h>
56 #include <rpc/rpc.h>
57 #include <assert.h>
58 #include <stdlib.h>
59 
60 #include "rpc_internal.h"
61 
62 #ifdef __weak_alias
63 __weak_alias(svc_auth_reg,_svc_auth_reg)
64 #endif
65 
66 /*
67  * svcauthsw is the bdevsw of server side authentication.
68  *
69  * Server side authenticators are called from authenticate by
70  * using the client auth struct flavor field to index into svcauthsw.
71  * The server auth flavors must implement a routine that looks
72  * like:
73  *
74  *	enum auth_stat
75  *	flavorx_auth(rqst, msg)
76  *		struct svc_req *rqst;
77  *		struct rpc_msg *msg;
78  *
79  */
80 
81 /* declarations to allow servers to specify new authentication flavors */
82 struct authsvc {
83 	int	flavor;
84 	enum	auth_stat (*handler)(struct svc_req *, struct rpc_msg *);
85 	struct	authsvc	  *next;
86 };
87 static struct authsvc *Auths = NULL;
88 
89 /*
90  * The call rpc message, msg has been obtained from the wire.  The msg contains
91  * the raw form of credentials and verifiers.  authenticate returns AUTH_OK
92  * if the msg is successfully authenticated.  If AUTH_OK then the routine also
93  * does the following things:
94  * set rqst->rq_xprt->verf to the appropriate response verifier;
95  * sets rqst->rq_client_cred to the "cooked" form of the credentials.
96  *
97  * NB: rqst->rq_cxprt->verf must be pre-allocated;
98  * its length is set appropriately.
99  *
100  * The caller still owns and is responsible for msg->u.cmb.cred and
101  * msg->u.cmb.verf.  The authentication system retains ownership of
102  * rqst->rq_client_cred, the cooked credentials.
103  *
104  * There is an assumption that any flavour less than AUTH_NULL is
105  * invalid.
106  */
107 enum auth_stat
_authenticate(struct svc_req * rqst,struct rpc_msg * msg)108 _authenticate(struct svc_req *rqst, struct rpc_msg *msg)
109 {
110 	int cred_flavor;
111 	struct authsvc *asp;
112 	enum auth_stat dummy;
113 
114 	_DIAGASSERT(rqst != NULL);
115 	_DIAGASSERT(msg != NULL);
116 
117 /* VARIABLES PROTECTED BY authsvc_lock: asp, Auths */
118 
119 	rqst->rq_cred = msg->rm_call.cb_cred;
120 	rqst->rq_xprt->xp_verf.oa_flavor = _null_auth.oa_flavor;
121 	rqst->rq_xprt->xp_verf.oa_length = 0;
122 	cred_flavor = rqst->rq_cred.oa_flavor;
123 	switch (cred_flavor) {
124 	case AUTH_NULL:
125 		dummy = _svcauth_null(rqst, msg);
126 		return (dummy);
127 	case AUTH_SYS:
128 		dummy = _svcauth_unix(rqst, msg);
129 		return (dummy);
130 	case AUTH_SHORT:
131 		dummy = _svcauth_short(rqst, msg);
132 		return (dummy);
133 #if 0
134 	case AUTH_DES:
135 		dummy = __svcauth_des(rqst, msg);
136 		return (dummy);
137 #endif
138 	default:
139 		break;
140 	}
141 
142 	/* flavor doesn't match any of the builtin types, so try new ones */
143 	mutex_lock(&authsvc_lock);
144 	for (asp = Auths; asp; asp = asp->next) {
145 		if (asp->flavor == cred_flavor) {
146 			enum auth_stat as;
147 
148 			as = (*asp->handler)(rqst, msg);
149 			mutex_unlock(&authsvc_lock);
150 			return (as);
151 		}
152 	}
153 	mutex_unlock(&authsvc_lock);
154 
155 	return (AUTH_REJECTEDCRED);
156 }
157 
158 /*ARGSUSED*/
159 enum auth_stat
_svcauth_null(struct svc_req * rqst,struct rpc_msg * msg)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 
179 int
svc_auth_reg(int cred_flavor,enum auth_stat (* handler)(struct svc_req *,struct rpc_msg *))180 svc_auth_reg(
181 	int cred_flavor,
182 	enum auth_stat (*handler)(struct svc_req *, struct rpc_msg *))
183 {
184 	struct authsvc *asp;
185 
186 	switch (cred_flavor) {
187 	    case AUTH_NULL:
188 	    case AUTH_SYS:
189 	    case AUTH_SHORT:
190 #if 0
191 	    case AUTH_DES:
192 #endif
193 		/* already registered */
194 		return (1);
195 
196 	    default:
197 		mutex_lock(&authsvc_lock);
198 		for (asp = Auths; asp; asp = asp->next) {
199 			if (asp->flavor == cred_flavor) {
200 				/* already registered */
201 				mutex_unlock(&authsvc_lock);
202 				return (1);
203 			}
204 		}
205 
206 		/* this is a new one, so go ahead and register it */
207 		asp = mem_alloc(sizeof (*asp));
208 		if (asp == NULL) {
209 			mutex_unlock(&authsvc_lock);
210 			return (-1);
211 		}
212 		asp->flavor = cred_flavor;
213 		asp->handler = handler;
214 		asp->next = Auths;
215 		Auths = asp;
216 		mutex_unlock(&authsvc_lock);
217 		break;
218 	}
219 	return (0);
220 }
221