source: rtems-libbsd/freebsd/lib/libc/rpc/svc_auth.c

#include <machine/rtems-bsd-user-space.h>

/*      $NetBSD: svc_auth.c,v 1.12 2000/07/06 03:10:35 christos Exp $   */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2009, Sun Microsystems, Inc.
 * All rights reserved.
 *
 * 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 Sun Microsystems, 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 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 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.
 */
/*
 * Copyright (c) 1986-1991 by Sun Microsystems Inc. 
 */

#if defined(LIBC_SCCS) && !defined(lint)
#ident  "@(#)svc_auth.c 1.16    94/04/24 SMI"
static char sccsid[] = "@(#)svc_auth.c 1.26 89/02/07 Copyr 1984 Sun Micro";
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

/*
 * svc_auth.c, Server-side rpc authenticator interface.
 *
 */

#include "namespace.h"
#include "reentrant.h"
#include <sys/types.h>
#include <rpc/rpc.h>
#include <stdlib.h>
#include "un-namespace.h"
#include "mt_misc.h"

/*
 * svcauthsw is the bdevsw of server side authentication.
 *
 * Server side authenticators are called from authenticate by
 * using the client auth struct flavor field to index into svcauthsw.
 * The server auth flavors must implement a routine that looks
 * like:
 *
 *      enum auth_stat
 *      flavorx_auth(rqst, msg)
 *              struct svc_req *rqst;
 *              struct rpc_msg *msg;
 *
 */

/* declarations to allow servers to specify new authentication flavors */
struct authsvc {
        int     flavor;
        enum    auth_stat (*handler)(struct svc_req *, struct rpc_msg *);
        struct  authsvc   *next;
};
static struct authsvc *Auths = NULL;

struct svc_auth_ops svc_auth_null_ops;

/*
 * The call rpc message, msg has been obtained from the wire.  The msg contains
 * the raw form of credentials and verifiers.  authenticate returns AUTH_OK
 * if the msg is successfully authenticated.  If AUTH_OK then the routine also
 * does the following things:
 * set rqst->rq_xprt->verf to the appropriate response verifier;
 * sets rqst->rq_client_cred to the "cooked" form of the credentials.
 *
 * NB: rqst->rq_cxprt->verf must be pre-alloctaed;
 * its length is set appropriately.
 *
 * The caller still owns and is responsible for msg->u.cmb.cred and
 * msg->u.cmb.verf.  The authentication system retains ownership of
 * rqst->rq_client_cred, the cooked credentials.
 *
 * There is an assumption that any flavour less than AUTH_NULL is
 * invalid.
 */
enum auth_stat
_authenticate(struct svc_req *rqst, struct rpc_msg *msg)
{
        int cred_flavor;
        struct authsvc *asp;
        enum auth_stat dummy;

/* VARIABLES PROTECTED BY authsvc_lock: asp, Auths */

        rqst->rq_cred = msg->rm_call.cb_cred;
        SVC_AUTH(rqst->rq_xprt).svc_ah_ops = &svc_auth_null_ops;
        SVC_AUTH(rqst->rq_xprt).svc_ah_private = NULL;
        rqst->rq_xprt->xp_verf.oa_flavor = _null_auth.oa_flavor;
        rqst->rq_xprt->xp_verf.oa_length = 0;
        cred_flavor = rqst->rq_cred.oa_flavor;
        switch (cred_flavor) {
        case AUTH_NULL:
                dummy = _svcauth_null(rqst, msg);
                return (dummy);
        case AUTH_SYS:
                dummy = _svcauth_unix(rqst, msg);
                return (dummy);
        case AUTH_SHORT:
                dummy = _svcauth_short(rqst, msg);
                return (dummy);
#ifdef DES_BUILTIN
        case AUTH_DES:
                dummy = _svcauth_des(rqst, msg);
                return (dummy);
#endif
        default:
                break;
        }

        /* flavor doesn't match any of the builtin types, so try new ones */
        mutex_lock(&authsvc_lock);
        for (asp = Auths; asp; asp = asp->next) {
                if (asp->flavor == cred_flavor) {
                        enum auth_stat as;

                        as = (*asp->handler)(rqst, msg);
                        mutex_unlock(&authsvc_lock);
                        return (as);
                }
        }
        mutex_unlock(&authsvc_lock);

        return (AUTH_REJECTEDCRED);
}

/*
 * A set of null auth methods used by any authentication protocols
 * that don't need to inspect or modify the message body.
 */
static bool_t
svcauth_null_wrap(SVCAUTH *auth, XDR *xdrs, xdrproc_t xdr_func, caddr_t xdr_ptr)
{

        return (xdr_func(xdrs, xdr_ptr));
}

struct svc_auth_ops svc_auth_null_ops = {
        svcauth_null_wrap,
        svcauth_null_wrap,
};

/*ARGSUSED*/
enum auth_stat
_svcauth_null(struct svc_req *rqst, struct rpc_msg *msg)
{
        return (AUTH_OK);
}

/*
 *  Allow the rpc service to register new authentication types that it is
 *  prepared to handle.  When an authentication flavor is registered,
 *  the flavor is checked against already registered values.  If not
 *  registered, then a new Auths entry is added on the list.
 *
 *  There is no provision to delete a registration once registered.
 *
 *  This routine returns:
 *       0 if registration successful
 *       1 if flavor already registered
 *      -1 if can't register (errno set)
 */

int
svc_auth_reg(int cred_flavor,
    enum auth_stat (*handler)(struct svc_req *, struct rpc_msg *))
{
        struct authsvc *asp;

        switch (cred_flavor) {
            case AUTH_NULL:
            case AUTH_SYS:
            case AUTH_SHORT:
#ifdef DES_BUILTIN
            case AUTH_DES:
#endif
                /* already registered */
                return (1);

            default:
                mutex_lock(&authsvc_lock);
                for (asp = Auths; asp; asp = asp->next) {
                        if (asp->flavor == cred_flavor) {
                                /* already registered */
                                mutex_unlock(&authsvc_lock);
                                return (1);
                        }
                }

                /* this is a new one, so go ahead and register it */
                asp = mem_alloc(sizeof (*asp));
                if (asp == NULL) {
                        mutex_unlock(&authsvc_lock);
                        return (-1);
                }
                asp->flavor = cred_flavor;
                asp->handler = handler;
                asp->next = Auths;
                Auths = asp;
                mutex_unlock(&authsvc_lock);
                break;
        }
        return (0);
}