1 /*
2  * svc_auth_unix.c
3  * Handles UNIX flavor authentication parameters on the service side of rpc.
4  * There are two svc auth implementations here: AUTH_UNIX and AUTH_SHORT.
5  * _svcauth_unix does full blown unix style uid,gid+gids auth,
6  * _svcauth_short uses a shorthand auth to index into a cache of longhand auths.
7  * Note: the shorthand has been gutted for efficiency.
8  *
9  * Copyright (c) 2010, Oracle America, Inc.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions are
13  * met:
14  *
15  *     * Redistributions of source code must retain the above copyright
16  *       notice, this list of conditions and the following disclaimer.
17  *     * Redistributions in binary form must reproduce the above
18  *       copyright notice, this list of conditions and the following
19  *       disclaimer in the documentation and/or other materials
20  *       provided with the distribution.
21  *     * Neither the name of the "Oracle America, Inc." nor the names of its
22  *       contributors may be used to endorse or promote products derived
23  *       from this software without specific prior written permission.
24  *
25  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
28  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
29  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
30  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
32  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
34  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
36  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <stdio.h>
40 #include <string.h>
41 #include <rpc/rpc.h>
42 #include <rpc/svc.h>
43 
44 /*
45  * Unix longhand authenticator
46  */
47 enum auth_stat
_svcauth_unix(struct svc_req * rqst,struct rpc_msg * msg)48 _svcauth_unix (struct svc_req *rqst, struct rpc_msg *msg)
49 {
50   enum auth_stat stat;
51   XDR xdrs;
52   struct authunix_parms *aup;
53   int32_t *buf;
54   struct area
55     {
56       struct authunix_parms area_aup;
57       char area_machname[MAX_MACHINE_NAME + 1];
58       gid_t area_gids[NGRPS];
59     }
60    *area;
61   u_int auth_len;
62   u_int str_len, gid_len;
63   u_int i;
64 
65   area = (struct area *) rqst->rq_clntcred;
66   aup = &area->area_aup;
67   aup->aup_machname = area->area_machname;
68   aup->aup_gids = area->area_gids;
69   auth_len = (u_int) msg->rm_call.cb_cred.oa_length;
70   xdrmem_create (&xdrs, msg->rm_call.cb_cred.oa_base, auth_len, XDR_DECODE);
71   buf = XDR_INLINE (&xdrs, auth_len);
72   if (buf != NULL)
73     {
74       aup->aup_time = IXDR_GET_LONG (buf);
75       str_len = IXDR_GET_U_INT32 (buf);
76       if (str_len > MAX_MACHINE_NAME)
77 	{
78 	  stat = AUTH_BADCRED;
79 	  goto done;
80 	}
81       memcpy (aup->aup_machname, (caddr_t) buf, (u_int) str_len);
82       aup->aup_machname[str_len] = 0;
83       str_len = RNDUP (str_len);
84       buf = (int32_t *) ((char *) buf + str_len);
85       aup->aup_uid = IXDR_GET_LONG (buf);
86       aup->aup_gid = IXDR_GET_LONG (buf);
87       gid_len = IXDR_GET_U_INT32 (buf);
88       if (gid_len > NGRPS)
89 	{
90 	  stat = AUTH_BADCRED;
91 	  goto done;
92 	}
93       aup->aup_len = gid_len;
94       for (i = 0; i < gid_len; i++)
95 	{
96 	  aup->aup_gids[i] = IXDR_GET_LONG (buf);
97 	}
98       /*
99        * five is the smallest unix credentials structure -
100        * timestamp, hostname len (0), uid, gid, and gids len (0).
101        */
102       if ((5 + gid_len) * BYTES_PER_XDR_UNIT + str_len > auth_len)
103 	{
104 	  stat = AUTH_BADCRED;
105 	  goto done;
106 	}
107     }
108   else if (!xdr_authunix_parms (&xdrs, aup))
109     {
110       xdrs.x_op = XDR_FREE;
111       (void) xdr_authunix_parms (&xdrs, aup);
112       stat = AUTH_BADCRED;
113       goto done;
114     }
115 
116   /* get the verifier */
117   if ((u_int)msg->rm_call.cb_verf.oa_length)
118     {
119       rqst->rq_xprt->xp_verf.oa_flavor =
120 	msg->rm_call.cb_verf.oa_flavor;
121       rqst->rq_xprt->xp_verf.oa_base =
122 	msg->rm_call.cb_verf.oa_base;
123       rqst->rq_xprt->xp_verf.oa_length =
124 	msg->rm_call.cb_verf.oa_length;
125     }
126   else
127     {
128       rqst->rq_xprt->xp_verf.oa_flavor = AUTH_NULL;
129       rqst->rq_xprt->xp_verf.oa_length = 0;
130     }
131   stat = AUTH_OK;
132 done:
133   XDR_DESTROY (&xdrs);
134   return stat;
135 }
136 
137 
138 /*
139  * Shorthand unix authenticator
140  * Looks up longhand in a cache.
141  */
142 /*ARGSUSED */
143 enum auth_stat
_svcauth_short(struct svc_req * rqst,struct rpc_msg * msg)144 _svcauth_short (struct svc_req *rqst, struct rpc_msg *msg)
145 {
146   return AUTH_REJECTEDCRED;
147 }
148