libnsl/rpc/svc_auth.c

	svc_auth.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
 * Portions of this source code were derived from Berkeley
 * 4.3 BSD under license from the Regents of the University of
 * California.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

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

#include "mt.h"
#include "rpc_mt.h"
#include <rpc/rpc.h>
#include <sys/types.h>
#include <rpc/trace.h>
#include <stdlib.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;
 *
 * The RPCSEC_GSS flavor is an exception.  Its routine takes an
 * additional boolean parameter that gets set to TRUE when the call
 * is not to be dispatched to the server.
 */

enum auth_stat __svcauth_null();    /* no authentication */
enum auth_stat __svcauth_sys();     /* (system) unix style (uid, gids) */
enum auth_stat __svcauth_short();   /* short hand unix style */
enum auth_stat __svcauth_des();     /* des style */
enum auth_stat __svcauth_loopback();    /* (loopback) unix style (uid, gids) */
extern enum auth_stat __svcrpcsec_gss();    /* GSS style */

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

/*
 * The call rpc message, msg has been obtained from the wire.  The msg contains
 * the raw form of credentials and verifiers.  no_dispatch is used and
 * dereferenced in subsequent gss function calls.  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
__gss_authenticate(rqst, msg, no_dispatch)
    struct svc_req *rqst;
    struct rpc_msg *msg;
    bool_t *no_dispatch;
{
    int cred_flavor;
    struct authsvc *asp;
    enum auth_stat dummy;
    extern mutex_t authsvc_lock;

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

    trace1(TR___gss_authenticate, 0);
    rqst->rq_cred = msg->rm_call.cb_cred;
    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;
    *no_dispatch = FALSE;
    switch (cred_flavor) {
    case AUTH_NULL:
        dummy = __svcauth_null(rqst, msg);
        trace1(TR___gss_authenticate, 1);
        return (dummy);
    case AUTH_SYS:
        dummy = __svcauth_sys(rqst, msg);
        trace1(TR___gss_authenticate, 1);
        return (dummy);
    case AUTH_SHORT:
        dummy = __svcauth_short(rqst, msg);
        trace1(TR___gss_authenticate, 1);
        return (dummy);
    case AUTH_DES:
        dummy = __svcauth_des(rqst, msg);
        trace1(TR___gss_authenticate, 1);
        return (dummy);
    case AUTH_LOOPBACK:
        dummy = __svcauth_loopback(rqst, msg);
        trace1(TR___gss_authenticate, 1);
        return (dummy);
    case RPCSEC_GSS:
        dummy = __svcrpcsec_gss(rqst, msg, no_dispatch);
        trace1(TR___gss_authenticate, 1);
        return (dummy);
    }

    /* 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);
            trace1(TR___gss_authenticate, 1);
            return (as);
        }
    }
    mutex_unlock(&authsvc_lock);

    trace1(TR___gss_authenticate, 1);
    return (AUTH_REJECTEDCRED);
}

/*
 * The following function __authenticate(rqst, msg) is preserved for
 * backward compatibility.
 */
enum auth_stat
__authenticate(rqst, msg)
    struct svc_req *rqst;
    struct rpc_msg *msg;
{
    bool_t no_dispatch;
    enum auth_stat st;

    trace1(TR___authenticate, 0);

    st = __gss_authenticate(rqst, msg, &no_dispatch);

    trace1(TR___authenticate, 1);
    return (st);
}

/*ARGSUSED*/
enum auth_stat
__svcauth_null(rqst, msg)
    struct svc_req *rqst;
    struct rpc_msg *msg;
{
    trace1(TR___svcauth_null, 0);
    trace1(TR___svcauth_null, 1);
    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(cred_flavor, handler)
    int cred_flavor;
    enum auth_stat (*handler)();
{
    struct authsvc *asp;
    extern mutex_t authsvc_lock;

    trace2(TR_svc_auth_reg, 0, cred_flavor);
    switch (cred_flavor) {
        case AUTH_NULL:
        case AUTH_SYS:
        case AUTH_SHORT:
        case AUTH_DES:
        case AUTH_LOOPBACK:
        case RPCSEC_GSS:
        /* already registered */
        trace1(TR_svc_auth_reg, 1);
        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);
                trace1(TR_svc_auth_reg, 1);
                return (1);
            }
        }

        /* this is a new one, so go ahead and register it */
        asp = (struct authsvc *)mem_alloc(sizeof (*asp));
        if (asp == NULL) {
            mutex_unlock(&authsvc_lock);
            trace1(TR_svc_auth_reg, 1);
            return (-1);
        }
        asp->flavor = cred_flavor;
        asp->handler = handler;
        asp->next = Auths;
        Auths = asp;
        mutex_unlock(&authsvc_lock);
        break;
    }
    trace1(TR_svc_auth_reg, 1);
    return (0);
}