usr.sbin/certctl/certctl.8

.\"	$NetBSD: certctl.8,v 1.3 2023/10/11 15:28:05 riastradh Exp $
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.Dd August 16, 2023
.Dt CERTCTL 8
.Os
.\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
.Sh NAME
.Nm certctl
.Nd configure OpenSSL certificate trust anchors
.\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
.Sh SYNOPSIS
.Nm
.Op Fl nv
.Op Fl C Ar config
.Op Fl c Ar certsdir
.Op Fl u Ar distrustdir
.Ar cmd
.Op Ar args...
.\""""""""""""""""""
.Nm
.Oo Ar options Oc Cm list
.Nm
.Oo Ar options Oc Cm rehash
.Nm
.Oo Ar options Oc Cm trust Ar cert
.Nm
.Oo Ar options Oc Cm untrust Ar cert
.Nm
.Oo Ar options Oc Cm untrusted
.\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
.Sh DESCRIPTION
The
.Nm
utility manages certificates used by OpenSSL-based applications as
trust anchors for certificate validation in TLS or other purposes,
for example by
.Xr ftp 1
in HTTPS.
.Nm
allows configuring the set of certificates and persistently excluding
individual certificates.
.Pp
For trust anchors to validate TLS certificates, OpenSSL applications
typically use a directory at
.Pa /etc/openssl/certs
of hashed certificates in PEM format, with names like
.Pa "3513523f.0"
used for lookup; see
.Xr openssl_rehash 1 .
.Pp
.Nm
scans all directories in the certificate search path specified by the
configuration file
.Ar config
.Pq default: Pa /etc/openssl/certs.conf
for files called
.Pa *.cer ,
.Pa *.crt ,
or
.Pa *.pem
in PEM format, and keeps
.Ar certsdir
.Pq default: Pa /etc/openssl/certs
populated with:
.Bl -dash
.It
symlinks to the original files in the certificate search path, for
applications that scan a directory for all files matching
.Pa *.cer ,
.Pa *.crt ,
or
.Pa *.pem ;
.It
hashed symlinks as in
.Xr openssl_rehash 1 ; and
.It
a single-file bundle
.Pa ca-certificates.crt
concatenating all the certificates in PEM format.
.El
.Pp
.Nm
will exclude from
.Ar certsdir
any certificates that have been marked untrustworthy with
.Nm Cm untrust ,
which are persistently maintained in the private state directory
.Ar distrustdir
.Pq default: Pa /etc/openssl/untrusted .
.Pp
.Nm
treats
.Ar config
and
.Ar distrustdir
as configuration, and treats
.Ar certsdir
strictly as a cache that can be safely deleted and rebuilt with
.Nm Cm rehash .
.Nm
can also be instructed not to touch
.Ar certsdir
at all by putting
.Cm manual
in
.Ar config .
.\""""""""""""""""""""""""""""""""""""""
.Ss Commands
.Bl -tag -width Cm
.\""""""""""""""""""
.It Cm list
List absolute paths to trusted certificates.
.Nm Cm rehash
will populate
.Ar certsdir
with these.
Paths are printed one per line, encoded in
.Xr vis 1
format to escape any shell metacharacters.
.\""""""""""""""""""
.It Cm rehash
Populate
.Ar certsdir
with all trusted certificates, excluding any from
.Nm Cm untrust .
.\""""""""""""""""""
.It Cm trust Ar cert
Allow
.Ar cert
to be included in
.Ar certsdir
if it is in the certificate search path, and rehash to make it
effective immediately.
In other words, reverse the persistent effect of
.Nm Cm untrust Ar cert .
.Pp
.Ar cert
must be the full absolute path to a certificate that has been excluded
by
.Nm Cm untrust Ar cert .
.Pp
This does not add a new certificate which is not in the search path.
To do that, you can create a directory to hold it and put that
directory in the search path.
.\""""""""""""""""""
.It Cm untrust Ar cert
Persistently prevent
.Ar cert
from being included in
.Ar certsdir ,
and rehash to make it effective immediately.
.Pp
.Ar cert
must be the full absolute path to a certificate that is in the
certificate search path.
.\""""""""""""""""""
.It Cm untrusted
List absolute paths to certificates that have been excluded by
.Nm Cm untrust .
.Nm Cm rehash
will not put these in
.Ar certsdir .
Paths are printed one per line, encoded in
.Xr vis 1
format to escape any shell metacharacters.
.\""""""""""""""""""
.El
.\""""""""""""""""""""""""""""""""""""""
.Ss Configuration file
The configuration file is a plain text file of lines separated by
.Tn US-ASCII
line feeds.
.Pp
.Pp
The first line must be:
.Dl netbsd-certctl 20230816
.Pp
Lines with only whitespace, or whitespace followed by the comment
character
.Ql #
are ignored.
Each line has a directive and arguments separated by whitespace, and
may be extended by
.Ql \e
to continuation lines.
.Bl -tag -width Cm
.\""""""""""""""""""
.It Cm path Ar dir
Add
.Ar dir
to the certificate search path.
.Ar dir
must be an absolute pathname,
.Xr vis 3 Ns -encoded
if it has any characters outside the class
.Ql "a-zA-Z0-9,.:=/+-" .
.Pp
All certificates must have unique base names across all directories
in the certificate search path.
.\""""""""""""""""""
.It Cm manual
Manual override.
If specified,
.Nm
will
.Em not
modify
.Ar certsdir ,
but may still check consistency of the configuration when run, and
.Nm Cm untrust
and
.Nm Cm trust
will still update
.Ar distrustdir .
.\""""""""""""""""""
.El
.\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
.Sh FILES
.Bl -tag -width Pa
.It Pa /etc/openssl/certs
Default directory of hashed TLS CA certificates.
.It Pa /etc/openssl/certs/ca-certificates.crt
Default single-file TLS CA certificate bundle.
.It Pa /etc/openssl/certs.conf
Default configuration file for TLS CA certificates.
.It Pa /etc/openssl/untrusted
Default
.Ar distrustdir
directory of excluded TLS CA certificates.
.It Pa /usr/share/certs/mozilla/all
All root CA certificates published by Mozilla, including untrustworthy
certificates.
.It Pa /usr/share/certs/mozilla/code
All root CA certificates published by Mozilla for use in code-signing.
.It Pa /usr/share/certs/mozilla/email
All root CA certificates published by Mozilla for use in email
authentication.
.It Pa /usr/share/certs/mozilla/server
All root CA certificates published by Mozilla for use in TLS server
authentication.
.El
.\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
.Sh EXAMPLES
Example configuration file
.Pq Pa /etc/openssl/certs.conf :
.Bd -literal -offset indent
netbsd-certctl 20230816

# Blank lines and comments are ignored.
# Comments begin with a `#' sign.

# Gather certificates from files called *.cer, *.crt, and *.pem
# under these directories.
path /usr/share/certs/mozilla/server
path /usr/pkg/share/chromium-cacerts
path /etc/openssl/certs.local

# If the next line is uncommented, certctl(8) will decline to
# touch /etc/openssl/certs.
#manual
.Ed
.Pp
Exclude a certificate:
.Bd -literal -offset indent
$ certctl untrust /usr/share/certs/mozilla/server/GTS_Root_R1.pem
.Ed
.Pp
There is no need to run
.Nm Cm rehash
explicitly after
.Nm Cm untrust ,
but if you do, the setting will persist.
.Pp
Rebuild the hashed certificate cache at
.Pa /etc/myapplication/certs
from
.Pa /etc/myapplication/certs.conf
and
.Pa /etc/myapplication/untrusted :
.Bd -literal -offset indent
$ certctl -c /etc/myapplication/certs \e
        -C /etc/myapplication/certs.conf \e
        -u /etc/myapplication/untrusted
.Ed
.\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
.Sh DIAGNOSTICS
.Ex -std
.\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
.Sh COMPATIBILITY
The
.Nm
utility is mostly compatible with a utility of the same name in
.Fx .
Differences:
.Bl -enum
.\""""""""""""""""""
.It
.Fx Nm
supports destdir/metalog handling;
.Nx Nm
does not.
.\""""""""""""""""""
.It
.Fx Nm
treats
.Pa /etc/ssl/certs
and
.Pa /etc/ssl/untrusted
both as configuration
.Em and
as caches;
.Nx Nm
treats
.Pa /etc/openssl/certs.conf
and
.Pa /etc/openssl/untrusted
as configuration, and treats
.Pa /etc/openssl/certs
strictly as a cache.
.Fx Nm
will forget any
.Nm Cm untrust
settings on
.Nm Cm rehash ,
but
.Nx Nm
will remember them.
.\""""""""""""""""""
.It
.Fx Nm
takes configuration through environment variables;
.Nx Nm
takes configuration through a file and command-line arguments.
.El
.\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
.Sh SEE ALSO
.Xr openssl 1 ,
.Xr openssl_rehash 1
.\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
.Sh HISTORY
.Nm
first appeared in
.Nx 10.0 .
A utility of the same name previously appeared in
.Fx 12.2 .