xref: /freebsd/usr.sbin/rpc.tlsclntd/rpc.tlsclntd.8 (revision 0aa4a9fc859fd43343e2d7b5094a50d1ca0948eb)
1.\" Copyright (c) 2008 Isilon Inc http://www.isilon.com/
2.\" Authors: Doug Rabson <dfr@rabson.org>
3.\" Developed with Red Inc: Alfred Perlstein <alfred@FreeBSD.org>
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26.\" Modified from gssd.8 for rpc.tlsclntd.8 by Rick Macklem.
27.Dd September 23, 2022
28.Dt RPC.TLSCLNTD 8
29.Os
30.Sh NAME
31.Nm rpc.tlsclntd
32.Nd "Sun RPC over TLS Client Daemon"
33.Sh SYNOPSIS
34.Nm
35.Op Fl 2
36.Op Fl C Ar available_ciphers
37.Op Fl D Ar certdir
38.Op Fl d
39.Op Fl l Ar CAfile
40.Op Fl m
41.Op Fl p Ar CApath
42.Op Fl r Ar CRLfile
43.Op Fl v
44.Sh DESCRIPTION
45The
46.Nm
47program provides support for the client side of the kernel Sun RPC over TLS
48implementation.
49This daemon must be running for the kernel RPC to be able to do a TLS
50connection to a server for an NFS over TLS mount.
51This daemon requires that the kernel be built with
52.Dq options KERNEL_TLS
53and be running on an architecture such as
54.Dq amd64
55that supports a direct map (not i386) with
56.Xr ktls 4
57enabled.
58.Pp
59If either of the
60.Fl l
61or
62.Fl p
63options have been specified, the daemon will require the server's
64certificate to verify
65and have a Fully Qualified Domain Name (FQDN) in it.
66This FQDN must match
67the reverse DNS name for the IP address that
68the server is using for the TCP connection.
69The FQDN may be
70in either the DNS field of the subjectAltName or the CN field of the
71subjectName in the certificate and
72cannot have a wildcard
73.Dq *
74in it.
75.Pp
76If a SIGHUP signal is sent to the daemon it will reload the
77.Dq CRLfile
78and will shut down any extant connections that presented certificates
79during TLS handshake that have been revoked.
80If the
81.Fl r
82option was not specified, the SIGHUP signal will be ignored.
83.Pp
84The daemon will log failed certificate verifications via
85.Xr syslogd 8
86using LOG_INFO | LOG_DAEMON when the
87.Fl l
88or
89.Fl p
90option has been specified.
91.Pp
92The options are as follows:
93.Bl -tag -width indent
94.It Fl 2 , Fl Fl usetls1_2
95Specify the use of TLS version 1.2.
96By default, the client will
97use TLS version 1.3, as required by the RFC.
98However, early
99.Fx
100.Pq 13.0 and 13.1
101servers require
102this option, since they only support TLS version 1.2.
103.It Fl C Ar available_ciphers , Fl Fl ciphers= Ns Ar available_ciphers
104Specify which ciphers are available during TLS handshake.
105If this option is specified,
106.Dq SSL_CTX_set_ciphersuites()
107will be called with
108.Dq available_ciphers
109as the argument.
110If this option is not specified, the cipher will be chosen by
111.Xr ssl 7 ,
112which should be adequate for most cases.
113The format for the available ciphers is a simple
114.So
115:
116.Sc
117separated list, in order of preference.
118The command
119.Dq openssl ciphers -s -tls1_3
120lists available ciphers.
121.It Fl D Ar certdir , Fl Fl certdir= Ns Ar certdir
122Use
123.Dq certdir
124instead of /etc/rpc.tlsclntd for the
125.Fl m
126option.
127.It Fl d , Fl Fl debuglevel
128Run in debug mode.
129In this mode,
130.Nm
131will not fork when it starts.
132.It Fl l Ar CAfile , Fl Fl verifylocs= Ns Ar CAfile
133This specifies the path name of a CAfile which holds the information
134for server certificate verification.
135This path name is used in
136.Dq SSL_CTX_load_verify_locations(ctx,CAfile,NULL)
137and
138.Dq SSL_CTX_set0_CA_list(ctx,SSL_load_client_CA_file(CAfile))
139openssl library calls.
140Note that this is a path name for the file and is not assumed to be
141in
142.Dq certdir .
143.It Fl m , Fl Fl mutualverf
144Enable support for mutual authentication.
145A certificate and associated key must be found in /etc/rpc.tlsclntd
146(or the directory specified by the
147.Fl D
148option)
149in case a server requests a peer certificate.
150The first certificate needs to be in a file named
151.Dq cert.pem
152and the associated key in a file named
153.Dq certkey.pem .
154The
155.Xr mount_nfs 8
156option
157.Fl tlscertname
158can be used to override the default certificate for a given
159NFS mount, where the files use the alternate naming specified by the option.
160If there is a passphrase on the
161.Dq certkey.pem
162file, this daemon will prompt for the passphrase during startup.
163The keys for alternate certificates cannot have passphrases.
164.It Fl p Ar CApath , Fl Fl verifydir= Ns Ar CApath
165This option is similar to the
166.Fl l
167option, but specifies the path of a directory with CA
168certificates in it.
169When this option is used,
170.Dq SSL_CTX_set0_CA_list(ctx,SSL_load_client_CA_file())
171is not called, so a list of CA names is not be passed
172to the server during the TLS handshake.
173The openssl documentation indicates this call is rarely needed.
174.It Fl r Ar CRLfile , Fl Fl crl= Ns Ar CRLfile
175This option specifies a Certificate Revocation List (CRL) file
176that is to be loaded into the verify certificate store and
177checked during verification of the server's certificate.
178This option is meaningless unless either the
179.Fl l
180or
181.Fl p
182have been specified.
183.It Fl v , Fl Fl verbose
184Run in verbose mode.
185In this mode,
186.Nm
187will log activity messages to syslog using LOG_INFO | LOG_DAEMON or to
188stderr, if the
189.Fl d
190option has also been specified.
191.El
192.Sh EXIT STATUS
193.Ex -std
194.Sh SEE ALSO
195.Xr openssl 1 ,
196.Xr ktls 4 ,
197.Xr ssl 7 ,
198.Xr mount_nfs 8 ,
199.Xr rpc.tlsservd 8 ,
200.Xr syslogd 8
201.Sh STANDARDS
202The implementation is based on the specification in
203.Rs
204.%B "RFC 9289"
205.%T "Towards Remote Procedure Call Encryption By Default"
206.Re
207.Sh HISTORY
208The
209.Nm
210manual page first appeared in
211.Fx 13.0 .
212.Sh BUGS
213This daemon cannot be safely shut down and restarted if there are
214any active RPC-over-TLS connections.
215Doing so will orphan the KERNEL_TLS connections, so that they
216can no longer do upcalls successfully, since the
217.Dq SSL *
218structures in userspace have been lost.
219