Authors: Doug Rabson <dfr@rabson.org>
Developed with Red Inc: Alfred Perlstein <alfred@FreeBSD.org>
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. 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.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
$FreeBSD$
Modified from gssd.8 for rpc.tlsclntd.8 by Rick Macklem.
.Dd February 17, 2021 .Dt RPC.TLSCLNTD 8 .Os .Sh NAME .Nm rpc.tlsclntd .Nd "Sun RPC over TLS Client Daemon" .Sh SYNOPSIS .Nm .Op Fl C Ar preferred_ciphers .Op Fl D Ar certdir .Op Fl d .Op Fl l Ar CAfile .Op Fl m .Op Fl p Ar CApath .Op Fl r Ar CRLfile .Op Fl v .Sh DESCRIPTION The .Nm program provides support for the client side of the kernel Sun RPC over TLS implementation. This daemon must be running for the kernel RPC to be able to do a TLS connection to a server for an NFS over TLS mount. This daemon requires that the kernel be built with .Dq options KERNEL_TLS and be running on an architecture such as .Dq amd64 that supports a direct map (not i386) with .Xr ktls 4 enabled.
p If either of the .Fl l or .Fl p options have been specified, the daemon will require the server's certificate to verify and have a Fully Qualified Domain Name (FQDN) in it. This FQDN must match the reverse DNS name for the IP address that the server is using for the TCP connection. The FQDN may be in either the DNS field of the subjectAltName or the CN field of the subjectName in the certificate and cannot have a wildcard .Dq * in it.
p If a SIGHUP signal is sent to the daemon it will reload the .Dq CRLfile and will shut down any extant connections that presented certificates during TLS handshake that have been revoked. If the .Fl r option was not specified, the SIGHUP signal will be ignored.
p The daemon will log failed certificate verifications via .Xr syslogd 8 using LOG_INFO | LOG_DAEMON when the .Fl l or .Fl p option has been specified.
p The options are as follows: l -tag -width indent t Fl C Ar preferred_ciphers , Fl Fl ciphers= Ns Ar preferred_ciphers Specify what preferred ciphers are to be used. If this option is specified, .Dq SSL_CTX_set_cipher_list() will be called with .Dq preferred_ciphers as the argument. If this option is not specified, the cipher will be chosen by .Xr ssl 7 . t Fl D Ar certdir , Fl Fl certdir= Ns Ar certdir Use .Dq certdir instead of /etc/rpc.tlsclntd for the .Fl m option. t Fl d , Fl Fl debuglevel Run in debug mode. In this mode, .Nm will not fork when it starts. t Fl l Ar CAfile , Fl Fl verifylocs= Ns Ar CAfile This specifies the path name of a CAfile which holds the information for server certificate verification. This path name is used in .Dq SSL_CTX_load_verify_locations(ctx,CAfile,NULL) and .Dq SSL_CTX_set0_CA_list(ctx,SSL_load_client_CA_file(CAfile)) openssl library calls. Note that this is a path name for the file and is not assumed to be in .Dq certdir . t Fl m , Fl Fl mutualverf Enable support for mutual authentication. A certificate and associated key must be found in /etc/rpc.tlsclntd (or the directory specified by the .Fl D option) in case a server requests a peer certificate. The first certificate needs to be in a file named .Dq cert.pem and the associated key in a file named .Dq certkey.pem . The .Xr mount_nfs 8 option .Fl tlscertname can be used to override the default certificate for a given NFS mount, where the files use the alternate naming specified by the option. If there is a passphrase on the .Dq certkey.pem file, this daemon will prompt for the passphrase during startup. The keys for alternate certificates cannot have passphrases. t Fl p Ar CApath , Fl Fl verifydir= Ns Ar CApath This option is similar to the .Fl l option, but specifies the path of a directory with CA certificates in it. When this option is used, .Dq SSL_CTX_set0_CA_list(ctx,SSL_load_client_CA_file()) is not called, so a list of CA names is not be passed to the server during the TLS handshake. The openssl documentation indicates this call is rarely needed. t Fl r Ar CRLfile , Fl Fl crl= Ns Ar CRLfile This option specifies a Certificate Revocation List (CRL) file that is to be loaded into the verify certificate store and checked during verification of the server's certificate. This option is meaningless unless either the .Fl l or .Fl p have been specified. t Fl v , Fl Fl verbose Run in verbose mode. In this mode, .Nm will log activity messages to syslog using LOG_INFO | LOG_DAEMON or to stderr, if the .Fl d option has also been specified. .El .Sh EXIT STATUS .Ex -std .Sh SEE ALSO .Xr openssl 1 , .Xr ktls 4 , .Xr mount_nfs 8 , .Xr rpc.tlsservd 8 , .Xr ssl 7 , .Xr syslogd 8 .Sh STANDARDS The implementation is based on the specification in .Rs .%B "RFC NNNN" .%T "Towards Remote Procedure Call Encryption By Default" .Re .Sh HISTORY The .Nm manual page first appeared in .Fx 13.0 . .Sh BUGS This daemon cannot be safely shut down and restarted if there are any active RPC-over-TLS connections. Doing so will orphan the KERNEL_TLS connections, so that they can no longer do upcalls successfully, since the .Dq SSL * structures in userspace have been lost.