xref: /freebsd/sys/rpc/svc_auth.c (revision 577b62c2bacc7dfa228591ca3da361e1bc398301)
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/proc.h>
52 #include <sys/systm.h>
53 #include <sys/jail.h>
54 #include <sys/ucred.h>
55 
56 #include <rpc/rpc.h>
57 #include <rpc/rpcsec_tls.h>
58 
59 static enum auth_stat (*_svcauth_rpcsec_gss)(struct svc_req *,
60     struct rpc_msg *) = NULL;
61 static int (*_svcauth_rpcsec_gss_getcred)(struct svc_req *,
62     struct ucred **, int *);
63 
64 static const struct svc_auth_ops svc_auth_null_ops;
65 
66 /*
67  * The call rpc message, msg has been obtained from the wire.  The msg contains
68  * the raw form of credentials and verifiers.  authenticate returns AUTH_OK
69  * if the msg is successfully authenticated.  If AUTH_OK then the routine also
70  * does the following things:
71  * set rqst->rq_xprt->verf to the appropriate response verifier;
72  * sets rqst->rq_client_cred to the "cooked" form of the credentials.
73  *
74  * NB: rqst->rq_cxprt->verf must be pre-allocated;
75  * its length is set appropriately.
76  *
77  * The caller still owns and is responsible for msg->u.cmb.cred and
78  * msg->u.cmb.verf.  The authentication system retains ownership of
79  * rqst->rq_client_cred, the cooked credentials.
80  *
81  * There is an assumption that any flavour less than AUTH_NULL is
82  * invalid.
83  */
84 enum auth_stat
85 _authenticate(struct svc_req *rqst, struct rpc_msg *msg)
86 {
87 	int cred_flavor;
88 	enum auth_stat dummy;
89 
90 	rqst->rq_cred = msg->rm_call.cb_cred;
91 	rqst->rq_auth.svc_ah_ops = &svc_auth_null_ops;
92 	rqst->rq_auth.svc_ah_private = NULL;
93 	cred_flavor = rqst->rq_cred.oa_flavor;
94 	switch (cred_flavor) {
95 	case AUTH_NULL:
96 		dummy = _svcauth_null(rqst, msg);
97 		return (dummy);
98 	case AUTH_SYS:
99 		if ((rqst->rq_xprt->xp_tls & RPCTLS_FLAGS_DISABLED) != 0)
100 			return (AUTH_REJECTEDCRED);
101 		dummy = _svcauth_unix(rqst, msg);
102 		return (dummy);
103 	case AUTH_SHORT:
104 		if ((rqst->rq_xprt->xp_tls & RPCTLS_FLAGS_DISABLED) != 0)
105 			return (AUTH_REJECTEDCRED);
106 		dummy = _svcauth_short(rqst, msg);
107 		return (dummy);
108 	case RPCSEC_GSS:
109 		if ((rqst->rq_xprt->xp_tls & RPCTLS_FLAGS_DISABLED) != 0)
110 			return (AUTH_REJECTEDCRED);
111 		if (!_svcauth_rpcsec_gss)
112 			return (AUTH_REJECTEDCRED);
113 		dummy = _svcauth_rpcsec_gss(rqst, msg);
114 		return (dummy);
115 	case AUTH_TLS:
116 		dummy = _svcauth_rpcsec_tls(rqst, msg);
117 		return (dummy);
118 	default:
119 		break;
120 	}
121 
122 	return (AUTH_REJECTEDCRED);
123 }
124 
125 /*
126  * A set of null auth methods used by any authentication protocols
127  * that don't need to inspect or modify the message body.
128  */
129 static bool_t
130 svcauth_null_wrap(SVCAUTH *auth, struct mbuf **mp)
131 {
132 
133 	return (TRUE);
134 }
135 
136 static bool_t
137 svcauth_null_unwrap(SVCAUTH *auth, struct mbuf **mp)
138 {
139 
140 	return (TRUE);
141 }
142 
143 static void
144 svcauth_null_release(SVCAUTH *auth)
145 {
146 
147 }
148 
149 static const struct svc_auth_ops svc_auth_null_ops = {
150 	.svc_ah_wrap = svcauth_null_wrap,
151 	.svc_ah_unwrap = svcauth_null_unwrap,
152 	.svc_ah_release = svcauth_null_release,
153 };
154 
155 /*ARGSUSED*/
156 enum auth_stat
157 _svcauth_null(struct svc_req *rqst, struct rpc_msg *msg)
158 {
159 
160 	rqst->rq_verf = _null_auth;
161 	return (AUTH_OK);
162 }
163 
164 int
165 svc_auth_reg(int flavor,
166     enum auth_stat (*svcauth)(struct svc_req *, struct rpc_msg *),
167     int (*getcred)(struct svc_req *, struct ucred **, int *))
168 {
169 
170 	if (flavor == RPCSEC_GSS) {
171 		_svcauth_rpcsec_gss = svcauth;
172 		_svcauth_rpcsec_gss_getcred = getcred;
173 	}
174 	return (TRUE);
175 }
176 
177 int
178 svc_getcred(struct svc_req *rqst, struct ucred **crp, int *flavorp)
179 {
180 	struct ucred *cr = NULL;
181 	int flavor;
182 	struct xucred *xcr;
183 	SVCXPRT *xprt = rqst->rq_xprt;
184 
185 	flavor = rqst->rq_cred.oa_flavor;
186 	if (flavorp)
187 		*flavorp = flavor;
188 
189 	/*
190 	 * If there are credentials acquired via a TLS
191 	 * certificate for this TCP connection, use those
192 	 * instead of what is in the RPC header.
193 	 */
194 	if ((xprt->xp_tls & (RPCTLS_FLAGS_CERTUSER |
195 	    RPCTLS_FLAGS_DISABLED)) == RPCTLS_FLAGS_CERTUSER &&
196 	    flavor == AUTH_UNIX) {
197 		cr = crget();
198 		cr->cr_uid = cr->cr_ruid = cr->cr_svuid = xprt->xp_uid;
199 		crsetgroups(cr, xprt->xp_ngrps, xprt->xp_gidp);
200 		cr->cr_rgid = cr->cr_svgid = xprt->xp_gidp[0];
201 		cr->cr_prison = curthread->td_ucred->cr_prison;
202 		prison_hold(cr->cr_prison);
203 		*crp = cr;
204 		return (TRUE);
205 	}
206 
207 	switch (flavor) {
208 	case AUTH_UNIX:
209 		xcr = (struct xucred *) rqst->rq_clntcred;
210 		cr = crget();
211 		cr->cr_uid = cr->cr_ruid = cr->cr_svuid = xcr->cr_uid;
212 		crsetgroups(cr, xcr->cr_ngroups, xcr->cr_groups);
213 		cr->cr_rgid = cr->cr_svgid = cr->cr_groups[0];
214 		cr->cr_prison = curthread->td_ucred->cr_prison;
215 		prison_hold(cr->cr_prison);
216 		*crp = cr;
217 		return (TRUE);
218 
219 	case RPCSEC_GSS:
220 		if (!_svcauth_rpcsec_gss_getcred)
221 			return (FALSE);
222 		return (_svcauth_rpcsec_gss_getcred(rqst, crp, flavorp));
223 
224 	default:
225 		return (FALSE);
226 	}
227 }
228 
229