xref: /freebsd/sys/rpc/svc_auth.c (revision f61c48f4403fc8c69f9b933d3f1bd9663008b0eb)
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 <sys/param.h>
42 #include <sys/conf.h>
43 #include <sys/lock.h>
44 #include <sys/mutex.h>
45 #include <sys/proc.h>
46 #include <sys/systm.h>
47 #include <sys/jail.h>
48 #include <sys/ucred.h>
49 
50 #include <rpc/rpc.h>
51 #include <rpc/rpcsec_tls.h>
52 
53 static enum auth_stat (*_svcauth_rpcsec_gss)(struct svc_req *,
54     struct rpc_msg *) = NULL;
55 static int (*_svcauth_rpcsec_gss_getcred)(struct svc_req *,
56     struct ucred **, int *);
57 
58 static const struct svc_auth_ops svc_auth_null_ops;
59 
60 /*
61  * The call rpc message, msg has been obtained from the wire.  The msg contains
62  * the raw form of credentials and verifiers.  authenticate returns AUTH_OK
63  * if the msg is successfully authenticated.  If AUTH_OK then the routine also
64  * does the following things:
65  * set rqst->rq_xprt->verf to the appropriate response verifier;
66  * sets rqst->rq_client_cred to the "cooked" form of the credentials.
67  *
68  * NB: rqst->rq_cxprt->verf must be pre-allocated;
69  * its length is set appropriately.
70  *
71  * The caller still owns and is responsible for msg->u.cmb.cred and
72  * msg->u.cmb.verf.  The authentication system retains ownership of
73  * rqst->rq_client_cred, the cooked credentials.
74  *
75  * There is an assumption that any flavour less than AUTH_NULL is
76  * invalid.
77  */
78 enum auth_stat
_authenticate(struct svc_req * rqst,struct rpc_msg * msg)79 _authenticate(struct svc_req *rqst, struct rpc_msg *msg)
80 {
81 	int cred_flavor;
82 	enum auth_stat dummy;
83 
84 	rqst->rq_cred = msg->rm_call.cb_cred;
85 	rqst->rq_auth.svc_ah_ops = &svc_auth_null_ops;
86 	rqst->rq_auth.svc_ah_private = NULL;
87 	cred_flavor = rqst->rq_cred.oa_flavor;
88 	switch (cred_flavor) {
89 	case AUTH_NULL:
90 		dummy = _svcauth_null(rqst, msg);
91 		return (dummy);
92 	case AUTH_SYS:
93 		if ((rqst->rq_xprt->xp_tls & RPCTLS_FLAGS_DISABLED) != 0)
94 			return (AUTH_REJECTEDCRED);
95 		dummy = _svcauth_unix(rqst, msg);
96 		return (dummy);
97 	case AUTH_SHORT:
98 		if ((rqst->rq_xprt->xp_tls & RPCTLS_FLAGS_DISABLED) != 0)
99 			return (AUTH_REJECTEDCRED);
100 		dummy = _svcauth_short(rqst, msg);
101 		return (dummy);
102 	case RPCSEC_GSS:
103 		if ((rqst->rq_xprt->xp_tls & RPCTLS_FLAGS_DISABLED) != 0)
104 			return (AUTH_REJECTEDCRED);
105 		if (!_svcauth_rpcsec_gss)
106 			return (AUTH_REJECTEDCRED);
107 		dummy = _svcauth_rpcsec_gss(rqst, msg);
108 		return (dummy);
109 	case AUTH_TLS:
110 		dummy = _svcauth_rpcsec_tls(rqst, msg);
111 		return (dummy);
112 	default:
113 		break;
114 	}
115 
116 	return (AUTH_REJECTEDCRED);
117 }
118 
119 /*
120  * A set of null auth methods used by any authentication protocols
121  * that don't need to inspect or modify the message body.
122  */
123 static bool_t
svcauth_null_wrap(SVCAUTH * auth,struct mbuf ** mp)124 svcauth_null_wrap(SVCAUTH *auth, struct mbuf **mp)
125 {
126 
127 	return (TRUE);
128 }
129 
130 static bool_t
svcauth_null_unwrap(SVCAUTH * auth,struct mbuf ** mp)131 svcauth_null_unwrap(SVCAUTH *auth, struct mbuf **mp)
132 {
133 
134 	return (TRUE);
135 }
136 
137 static void
svcauth_null_release(SVCAUTH * auth)138 svcauth_null_release(SVCAUTH *auth)
139 {
140 
141 }
142 
143 static const struct svc_auth_ops svc_auth_null_ops = {
144 	.svc_ah_wrap = svcauth_null_wrap,
145 	.svc_ah_unwrap = svcauth_null_unwrap,
146 	.svc_ah_release = svcauth_null_release,
147 };
148 
149 /*ARGSUSED*/
150 enum auth_stat
_svcauth_null(struct svc_req * rqst,struct rpc_msg * msg)151 _svcauth_null(struct svc_req *rqst, struct rpc_msg *msg)
152 {
153 
154 	rqst->rq_verf = _null_auth;
155 	return (AUTH_OK);
156 }
157 
158 int
svc_auth_reg(int flavor,enum auth_stat (* svcauth)(struct svc_req *,struct rpc_msg *),int (* getcred)(struct svc_req *,struct ucred **,int *))159 svc_auth_reg(int flavor,
160     enum auth_stat (*svcauth)(struct svc_req *, struct rpc_msg *),
161     int (*getcred)(struct svc_req *, struct ucred **, int *))
162 {
163 
164 	if (flavor == RPCSEC_GSS) {
165 		_svcauth_rpcsec_gss = svcauth;
166 		_svcauth_rpcsec_gss_getcred = getcred;
167 	}
168 	return (TRUE);
169 }
170 
171 int
svc_getcred(struct svc_req * rqst,struct ucred ** crp,int * flavorp)172 svc_getcred(struct svc_req *rqst, struct ucred **crp, int *flavorp)
173 {
174 	struct ucred *cr = NULL;
175 	int flavor;
176 	struct xucred *xcr;
177 	SVCXPRT *xprt = rqst->rq_xprt;
178 
179 	flavor = rqst->rq_cred.oa_flavor;
180 	if (flavorp)
181 		*flavorp = flavor;
182 
183 	/*
184 	 * If there are credentials acquired via a TLS
185 	 * certificate for this TCP connection, use those
186 	 * instead of what is in the RPC header.
187 	 */
188 	if ((xprt->xp_tls & (RPCTLS_FLAGS_CERTUSER |
189 	    RPCTLS_FLAGS_DISABLED)) == RPCTLS_FLAGS_CERTUSER &&
190 	    flavor == AUTH_UNIX) {
191 		if (xprt->xp_ngrps <= 0)
192 			return (FALSE);
193 		cr = crget();
194 		cr->cr_uid = cr->cr_ruid = cr->cr_svuid = xprt->xp_uid;
195 		crsetgroups_and_egid(cr, xprt->xp_ngrps, xprt->xp_gidp, GID_NOGROUP);
196 		cr->cr_rgid = cr->cr_svgid = cr->cr_gid;
197 		cr->cr_prison = curthread->td_ucred->cr_prison;
198 		prison_hold(cr->cr_prison);
199 		*crp = cr;
200 		return (TRUE);
201 	}
202 
203 	switch (flavor) {
204 	case AUTH_UNIX:
205 		xcr = (struct xucred *) rqst->rq_clntcred;
206 		if (xcr->cr_ngroups <= 0)
207 			return (FALSE);
208 		cr = crget();
209 		cr->cr_uid = cr->cr_ruid = cr->cr_svuid = xcr->cr_uid;
210 		crsetgroups_and_egid(cr, xcr->cr_ngroups, xcr->cr_groups, GID_NOGROUP);
211 		cr->cr_rgid = cr->cr_svgid = cr->cr_gid;
212 		cr->cr_prison = curthread->td_ucred->cr_prison;
213 		prison_hold(cr->cr_prison);
214 		*crp = cr;
215 		return (TRUE);
216 
217 	case RPCSEC_GSS:
218 		if (!_svcauth_rpcsec_gss_getcred)
219 			return (FALSE);
220 		return (_svcauth_rpcsec_gss_getcred(rqst, crp, flavorp));
221 
222 	default:
223 		return (FALSE);
224 	}
225 }
226 
227