/*      $OpenBSD: svc_auth_unix.c,v 1.13 2015/11/01 03:45:29 guenther Exp $ */

/*
 * Copyright (c) 2010, Oracle America, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 *     * Neither the name of the "Oracle America, Inc." nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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 *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * svc_auth_unix.c
 * Handles UNIX flavor authentication parameters on the service side of rpc.
 * There are two svc auth implementations here: AUTH_UNIX and AUTH_SHORT.
 * _svcauth_unix does full blown unix style uid,gid+gids auth,
 * _svcauth_short uses a shorthand auth to index into a cache of longhand auths.
 * Note: the shorthand has been gutted for efficiency.
 */

#include <stdio.h>
#include <rpc/rpc.h>
#include <string.h>

/*
 * Unix longhand authenticator
 */
enum auth_stat
_svcauth_unix(struct svc_req *rqst, struct rpc_msg *msg)
{
        enum auth_stat stat;
        XDR xdrs;
        struct authunix_parms *aup;
        int32_t *buf;
        struct area {
                struct authunix_parms area_aup;
                char area_machname[MAX_MACHINE_NAME+1];
                int area_gids[NGRPS];
        } *area;
        u_int auth_len;
        u_int str_len, gid_len;
        u_int i;

        area = (struct area *) rqst->rq_clntcred;
        aup = &area->area_aup;
        aup->aup_machname = area->area_machname;
        aup->aup_gids = area->area_gids;
        auth_len = (u_int)msg->rm_call.cb_cred.oa_length;
        xdrmem_create(&xdrs, msg->rm_call.cb_cred.oa_base, auth_len,XDR_DECODE);
        buf = XDR_INLINE(&xdrs, auth_len);
        if (buf != NULL) {
                aup->aup_time = IXDR_GET_LONG(buf);
                str_len = IXDR_GET_U_LONG(buf);
                if (str_len > MAX_MACHINE_NAME) {
                        stat = AUTH_BADCRED;
                        goto done;
                }
                memcpy(aup->aup_machname, (caddr_t)buf, (u_int)str_len);
                aup->aup_machname[str_len] = 0;
                str_len = RNDUP(str_len);
                buf += str_len / sizeof (int32_t);
                aup->aup_uid = IXDR_GET_LONG(buf);
                aup->aup_gid = IXDR_GET_LONG(buf);
                gid_len = IXDR_GET_U_LONG(buf);
                if (gid_len > NGRPS) {
                        stat = AUTH_BADCRED;
                        goto done;
                }
                aup->aup_len = gid_len;
                for (i = 0; i < gid_len; i++) {
                        aup->aup_gids[i] = IXDR_GET_LONG(buf);
                }
                /*
                 * five is the smallest unix credentials structure -
                 * timestamp, hostname len (0), uid, gid, and gids len (0).
                 */
                if ((5 + gid_len) * BYTES_PER_XDR_UNIT + str_len > auth_len) {
                        stat = AUTH_BADCRED;
                        goto done;
                }
        } else if (! xdr_authunix_parms(&xdrs, aup)) {
                xdrs.x_op = XDR_FREE;
                (void)xdr_authunix_parms(&xdrs, aup);
                stat = AUTH_BADCRED;
                goto done;
        }
        rqst->rq_xprt->xp_verf.oa_flavor = AUTH_NULL;
        rqst->rq_xprt->xp_verf.oa_length = 0;
        stat = AUTH_OK;
done:
        XDR_DESTROY(&xdrs);
        return (stat);
}
DEF_STRONG(_svcauth_unix);


/*
 * Shorthand unix authenticator
 * Looks up longhand in a cache.
 */
enum auth_stat 
_svcauth_short(struct svc_req *rqst, struct rpc_msg *msg)
{
        return (AUTH_REJECTEDCRED);
}
DEF_STRONG(_svcauth_short);