xref: /freebsd/sys/rpc/svc_auth.c (revision e8d8bef961a50d4dc22501cde4fb9fb0be1b2532)
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 #if defined(LIBC_SCCS) && !defined(lint)
37 #ident	"@(#)svc_auth.c	1.16	94/04/24 SMI"
38 static char sccsid[] = "@(#)svc_auth.c 1.26 89/02/07 Copyr 1984 Sun Micro";
39 #endif
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 /*
44  * svc_auth.c, Server-side rpc authenticator interface.
45  *
46  */
47 
48 #include <sys/param.h>
49 #include <sys/lock.h>
50 #include <sys/mutex.h>
51 #include <sys/systm.h>
52 #include <sys/jail.h>
53 #include <sys/ucred.h>
54 
55 #include <rpc/rpc.h>
56 #include <rpc/rpcsec_tls.h>
57 
58 static enum auth_stat (*_svcauth_rpcsec_gss)(struct svc_req *,
59     struct rpc_msg *) = NULL;
60 static int (*_svcauth_rpcsec_gss_getcred)(struct svc_req *,
61     struct ucred **, int *);
62 
63 static struct svc_auth_ops svc_auth_null_ops;
64 
65 /*
66  * The call rpc message, msg has been obtained from the wire.  The msg contains
67  * the raw form of credentials and verifiers.  authenticate returns AUTH_OK
68  * if the msg is successfully authenticated.  If AUTH_OK then the routine also
69  * does the following things:
70  * set rqst->rq_xprt->verf to the appropriate response verifier;
71  * sets rqst->rq_client_cred to the "cooked" form of the credentials.
72  *
73  * NB: rqst->rq_cxprt->verf must be pre-alloctaed;
74  * its length is set appropriately.
75  *
76  * The caller still owns and is responsible for msg->u.cmb.cred and
77  * msg->u.cmb.verf.  The authentication system retains ownership of
78  * rqst->rq_client_cred, the cooked credentials.
79  *
80  * There is an assumption that any flavour less than AUTH_NULL is
81  * invalid.
82  */
83 enum auth_stat
84 _authenticate(struct svc_req *rqst, struct rpc_msg *msg)
85 {
86 	int cred_flavor;
87 	enum auth_stat dummy;
88 
89 	rqst->rq_cred = msg->rm_call.cb_cred;
90 	rqst->rq_auth.svc_ah_ops = &svc_auth_null_ops;
91 	rqst->rq_auth.svc_ah_private = NULL;
92 	cred_flavor = rqst->rq_cred.oa_flavor;
93 	switch (cred_flavor) {
94 	case AUTH_NULL:
95 		dummy = _svcauth_null(rqst, msg);
96 		return (dummy);
97 	case AUTH_SYS:
98 		if ((rqst->rq_xprt->xp_tls & RPCTLS_FLAGS_DISABLED) != 0)
99 			return (AUTH_REJECTEDCRED);
100 		dummy = _svcauth_unix(rqst, msg);
101 		return (dummy);
102 	case AUTH_SHORT:
103 		if ((rqst->rq_xprt->xp_tls & RPCTLS_FLAGS_DISABLED) != 0)
104 			return (AUTH_REJECTEDCRED);
105 		dummy = _svcauth_short(rqst, msg);
106 		return (dummy);
107 	case RPCSEC_GSS:
108 		if ((rqst->rq_xprt->xp_tls & RPCTLS_FLAGS_DISABLED) != 0)
109 			return (AUTH_REJECTEDCRED);
110 		if (!_svcauth_rpcsec_gss)
111 			return (AUTH_REJECTEDCRED);
112 		dummy = _svcauth_rpcsec_gss(rqst, msg);
113 		return (dummy);
114 	case AUTH_TLS:
115 		dummy = _svcauth_rpcsec_tls(rqst, msg);
116 		return (dummy);
117 	default:
118 		break;
119 	}
120 
121 	return (AUTH_REJECTEDCRED);
122 }
123 
124 /*
125  * A set of null auth methods used by any authentication protocols
126  * that don't need to inspect or modify the message body.
127  */
128 static bool_t
129 svcauth_null_wrap(SVCAUTH *auth, struct mbuf **mp)
130 {
131 
132 	return (TRUE);
133 }
134 
135 static bool_t
136 svcauth_null_unwrap(SVCAUTH *auth, struct mbuf **mp)
137 {
138 
139 	return (TRUE);
140 }
141 
142 static void
143 svcauth_null_release(SVCAUTH *auth)
144 {
145 
146 }
147 
148 static struct svc_auth_ops svc_auth_null_ops = {
149 	svcauth_null_wrap,
150 	svcauth_null_unwrap,
151 	svcauth_null_release,
152 };
153 
154 /*ARGSUSED*/
155 enum auth_stat
156 _svcauth_null(struct svc_req *rqst, struct rpc_msg *msg)
157 {
158 
159 	rqst->rq_verf = _null_auth;
160 	return (AUTH_OK);
161 }
162 
163 int
164 svc_auth_reg(int flavor,
165     enum auth_stat (*svcauth)(struct svc_req *, struct rpc_msg *),
166     int (*getcred)(struct svc_req *, struct ucred **, int *))
167 {
168 
169 	if (flavor == RPCSEC_GSS) {
170 		_svcauth_rpcsec_gss = svcauth;
171 		_svcauth_rpcsec_gss_getcred = getcred;
172 	}
173 	return (TRUE);
174 }
175 
176 int
177 svc_getcred(struct svc_req *rqst, struct ucred **crp, int *flavorp)
178 {
179 	struct ucred *cr = NULL;
180 	int flavor;
181 	struct xucred *xcr;
182 	SVCXPRT *xprt = rqst->rq_xprt;
183 
184 	flavor = rqst->rq_cred.oa_flavor;
185 	if (flavorp)
186 		*flavorp = flavor;
187 
188 	/*
189 	 * If there are credentials acquired via a TLS
190 	 * certificate for this TCP connection, use those
191 	 * instead of what is in the RPC header.
192 	 */
193 	if ((xprt->xp_tls & (RPCTLS_FLAGS_CERTUSER |
194 	    RPCTLS_FLAGS_DISABLED)) == RPCTLS_FLAGS_CERTUSER &&
195 	    flavor == AUTH_UNIX) {
196 		cr = crget();
197 		cr->cr_uid = cr->cr_ruid = cr->cr_svuid = xprt->xp_uid;
198 		crsetgroups(cr, xprt->xp_ngrps, xprt->xp_gidp);
199 		cr->cr_rgid = cr->cr_svgid = xprt->xp_gidp[0];
200 		cr->cr_prison = &prison0;
201 		prison_hold(cr->cr_prison);
202 		*crp = cr;
203 		return (TRUE);
204 	}
205 
206 	switch (flavor) {
207 	case AUTH_UNIX:
208 		xcr = (struct xucred *) rqst->rq_clntcred;
209 		cr = crget();
210 		cr->cr_uid = cr->cr_ruid = cr->cr_svuid = xcr->cr_uid;
211 		crsetgroups(cr, xcr->cr_ngroups, xcr->cr_groups);
212 		cr->cr_rgid = cr->cr_svgid = cr->cr_groups[0];
213 		cr->cr_prison = &prison0;
214 		prison_hold(cr->cr_prison);
215 		*crp = cr;
216 		return (TRUE);
217 
218 	case RPCSEC_GSS:
219 		if (!_svcauth_rpcsec_gss_getcred)
220 			return (FALSE);
221 		return (_svcauth_rpcsec_gss_getcred(rqst, crp, flavorp));
222 
223 	default:
224 		return (FALSE);
225 	}
226 }
227 
228