freebsd-dev/sys/rpc/svc_auth.c
Rick Macklem ab0c29af05 Add TLS support to the kernel RPC.
An internet draft titled "Towards Remote Procedure Call Encryption By Default"
describes how TLS is to be used for Sun RPC, with NFS as an intended use case.
This patch adds client and server support for this to the kernel RPC,
using KERN_TLS and upcalls to daemons for the handshake, peer reset and
other non-application data record cases.

The upcalls to the daemons use three fields to uniquely identify the
TCP connection. They are the time.tv_sec, time.tv_usec of the connection
establshment, plus a 64bit sequence number. The time fields avoid problems
with re-use of the sequence number after a daemon restart.
For the server side, once a Null RPC with AUTH_TLS is received, kernel
reception on the socket is blocked and an upcall to the rpctlssd(8) daemon
is done to perform the TLS handshake.  Upon completion, the completion
status of the handshake is stored in xp_tls as flag bits and the reply to
the Null RPC is sent.
For the client, if CLSET_TLS has been set, a new TCP connection will
send the Null RPC with AUTH_TLS to initiate the handshake.  The client
kernel RPC code will then block kernel I/O on the socket and do an upcall
to the rpctlscd(8) daemon to perform the handshake.
If the upcall is successful, ct_rcvstate will be maintained to indicate
if/when an upcall is being done.

If non-application data records are received, the code does an upcall to
the appropriate daemon, which will do a SSL_read() of 0 length to handle
the record(s).

When the socket is being shut down, upcalls are done to the daemons, so
that they can perform SSL_shutdown() calls to perform the "peer reset".

The rpctlssd(8) and rpctlscd(8) daemons require a patched version of the
openssl library and, as such, will not be committed to head at this time.

Although the changes done by this patch are fairly numerous, there should
be no semantics change to the kernel RPC at this time.
A future commit to the NFS code will optionally enable use of TLS for NFS.
2020-08-22 03:57:55 +00:00

228 lines
6.3 KiB
C

/* $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 <sys/param.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/systm.h>
#include <sys/jail.h>
#include <sys/ucred.h>
#include <rpc/rpc.h>
#include <rpc/rpcsec_tls.h>
static enum auth_stat (*_svcauth_rpcsec_gss)(struct svc_req *,
struct rpc_msg *) = NULL;
static int (*_svcauth_rpcsec_gss_getcred)(struct svc_req *,
struct ucred **, int *);
static 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;
enum auth_stat dummy;
rqst->rq_cred = msg->rm_call.cb_cred;
rqst->rq_auth.svc_ah_ops = &svc_auth_null_ops;
rqst->rq_auth.svc_ah_private = NULL;
cred_flavor = rqst->rq_cred.oa_flavor;
switch (cred_flavor) {
case AUTH_NULL:
dummy = _svcauth_null(rqst, msg);
return (dummy);
case AUTH_SYS:
if ((rqst->rq_xprt->xp_tls & RPCTLS_FLAGS_DISABLED) != 0)
return (AUTH_REJECTEDCRED);
dummy = _svcauth_unix(rqst, msg);
return (dummy);
case AUTH_SHORT:
if ((rqst->rq_xprt->xp_tls & RPCTLS_FLAGS_DISABLED) != 0)
return (AUTH_REJECTEDCRED);
dummy = _svcauth_short(rqst, msg);
return (dummy);
case RPCSEC_GSS:
if ((rqst->rq_xprt->xp_tls & RPCTLS_FLAGS_DISABLED) != 0)
return (AUTH_REJECTEDCRED);
if (!_svcauth_rpcsec_gss)
return (AUTH_REJECTEDCRED);
dummy = _svcauth_rpcsec_gss(rqst, msg);
return (dummy);
case AUTH_TLS:
dummy = _svcauth_rpcsec_tls(rqst, msg);
return (dummy);
default:
break;
}
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, struct mbuf **mp)
{
return (TRUE);
}
static bool_t
svcauth_null_unwrap(SVCAUTH *auth, struct mbuf **mp)
{
return (TRUE);
}
static void
svcauth_null_release(SVCAUTH *auth)
{
}
static struct svc_auth_ops svc_auth_null_ops = {
svcauth_null_wrap,
svcauth_null_unwrap,
svcauth_null_release,
};
/*ARGSUSED*/
enum auth_stat
_svcauth_null(struct svc_req *rqst, struct rpc_msg *msg)
{
rqst->rq_verf = _null_auth;
return (AUTH_OK);
}
int
svc_auth_reg(int flavor,
enum auth_stat (*svcauth)(struct svc_req *, struct rpc_msg *),
int (*getcred)(struct svc_req *, struct ucred **, int *))
{
if (flavor == RPCSEC_GSS) {
_svcauth_rpcsec_gss = svcauth;
_svcauth_rpcsec_gss_getcred = getcred;
}
return (TRUE);
}
int
svc_getcred(struct svc_req *rqst, struct ucred **crp, int *flavorp)
{
struct ucred *cr = NULL;
int flavor;
struct xucred *xcr;
SVCXPRT *xprt = rqst->rq_xprt;
flavor = rqst->rq_cred.oa_flavor;
if (flavorp)
*flavorp = flavor;
/*
* If there are credentials acquired via a TLS
* certificate for this TCP connection, use those
* instead of what is in the RPC header.
*/
if ((xprt->xp_tls & (RPCTLS_FLAGS_CERTUSER |
RPCTLS_FLAGS_DISABLED)) == RPCTLS_FLAGS_CERTUSER &&
flavor == AUTH_UNIX) {
cr = crget();
cr->cr_uid = cr->cr_ruid = cr->cr_svuid = xprt->xp_uid;
crsetgroups(cr, xprt->xp_ngrps, xprt->xp_gidp);
cr->cr_rgid = cr->cr_svgid = xprt->xp_gidp[0];
cr->cr_prison = &prison0;
prison_hold(cr->cr_prison);
*crp = cr;
return (TRUE);
}
switch (flavor) {
case AUTH_UNIX:
xcr = (struct xucred *) rqst->rq_clntcred;
cr = crget();
cr->cr_uid = cr->cr_ruid = cr->cr_svuid = xcr->cr_uid;
crsetgroups(cr, xcr->cr_ngroups, xcr->cr_groups);
cr->cr_rgid = cr->cr_svgid = cr->cr_groups[0];
cr->cr_prison = &prison0;
prison_hold(cr->cr_prison);
*crp = cr;
return (TRUE);
case RPCSEC_GSS:
if (!_svcauth_rpcsec_gss_getcred)
return (FALSE);
return (_svcauth_rpcsec_gss_getcred(rqst, crp, flavorp));
default:
return (FALSE);
}
}