client.conf(5) OpenPrinting client.conf(5)
NAME
client.conf - client configuration file for cups (deprecated on
macos)
DESCRIPTION
The
client.conf file configures the CUPS client and is normally
located in the
/etc/cups and/or
~/.cups directories. Each line in
the file can be a configuration directive, a blank line, or a
comment. Comment lines start with the # character.
Note: Starting with macOS 10.7, this file is only used by command-
line and X11 applications plus the IPP backend. The
ServerName directive is not supported on macOS at all. Starting with macOS
10.12, all applications can access these settings in the
/Library/Preferences/org.cups.PrintingPrefs.plist file instead. See
the NOTES section below for more information.
DIRECTIVES
The following directives are understood by the client. Consult the
online help for detailed descriptions:
AllowAnyRoot Yes AllowAnyRoot No Specifies whether to allow TLS with certificates that have not
been signed by a trusted Certificate Authority. The default is
"Yes".
AllowExpiredCerts Yes AllowExpiredCerts No Specifies whether to allow TLS with expired certificates. The
default is "No".
DigestOptions DenyMD5 DigestOptions None Specifies HTTP Digest authentication options.
DenyMD5 disables
support for the original MD5 hash algorithm.
Encryption IfRequested Encryption Never Encryption Required Specifies the level of encryption that should be used.
GSSServiceName name Specifies the Kerberos service name that is used for
authentication, typically "host", "http", or "ipp". CUPS adds
the remote hostname ("name@server.example.com") for you. The
default name is "http".
ServerName hostname-or-ip-address[
:port]
ServerName /domain/socket Specifies the address and optionally the port to use when
connecting to the server.
Note: This directive is not supported on macOS 10.7 or later. ServerName hostname-or-ip-address[
:port]
/version=1.1 Specifies the address and optionally the port to use when
connecting to a server running CUPS 1.3.12 and earlier.
SSLOptions [
AllowDH] [
AllowRC4] [
AllowSSL3] [
DenyCBC] [
DenyTLS1.0]
[
MaxTLS1.0] [
MaxTLS1.1] [
MaxTLS1.2] [
MaxTLS1.3] [
MinTLS1.0]
[
MinTLS1.1] [
MinTLS1.2] [
MinTLS1.3]
SSLOptions None Sets encryption options (only in /etc/cups/client.conf). By
default, CUPS only supports encryption using TLS v1.0 or higher
using known secure cipher suites. Security is reduced when
Allow options are used. Security is enhanced when
Deny options
are used. The
AllowDH option enables cipher suites using plain
Diffie-Hellman key negotiation (not supported on systems using
GNU TLS). The
AllowRC4 option enables the 128-bit RC4 cipher
suites, which are required for some older clients. The
AllowSSL3 option enables SSL v3.0, which is required for some
older clients that do not support TLS v1.0. The
DenyCBC option
disables all CBC cipher suites. The
DenyTLS1.0 option disables
TLS v1.0 support - this sets the minimum protocol version to TLS
v1.1. The
MinTLS options set the minimum TLS version to
support. The
MaxTLS options set the maximum TLS version to
support. Not all operating systems support TLS 1.3 at this
time.
TrustOnFirstUse Yes TrustOnFirstUse No Specifies whether to trust new TLS certificates by default. The
default is "Yes".
User name Specifies the default user name to use for requests.
UserAgentTokens None UserAgentTokens ProductOnly UserAgentTokens Major UserAgentTokens Minor UserAgentTokens Minimal UserAgentTokens OS UserAgentTokens Full Specifies what information is included in the User-Agent header
of HTTP requests. "None" disables the User-Agent header.
"ProductOnly" reports "CUPS". "Major" reports "CUPS/major
IPP/2". "Minor" reports "CUPS/major.minor IPP/2.1". "Minimal"
reports "CUPS/major.minor.patch IPP/2.1". "OS" reports
"CUPS/major.minor.path (osname osversion) IPP/2.1". "Full"
reports "CUPS/major.minor.path (osname osversion; architecture)
IPP/2.1". The default is "Minimal".
ValidateCerts Yes ValidateCerts No Specifies whether to only allow TLS with certificates whose
common name matches the hostname. The default is "No".
NOTES
The
client.conf file is deprecated on macOS and will no longer be
supported in a future version of CUPS. Configuration settings can
instead be viewed or changed using the
defaults(1) command:
defaults write /Library/Preferences/org.cups.PrintingPrefs.plist Encryption Required
defaults write /Library/Preferences/org.cups.PrintingPrefs.plist TrustOnFirstUse -bool NO
defaults read /Library/Preferences/org.cups.PrintingPrefs.plist Encryption
On Linux and other systems using GNU TLS, the
/etc/cups/ssl/site.crl file, if present, provides a list of revoked X.509 certificates and
is used when validating certificates.
SEE ALSO
cups(1),
default(1), CUPS Online Help (http://localhost:631/help)
COPYRIGHT
Copyright (C) 2020-2024 by OpenPrinting.
2021-02-28 CUPS client.conf(5)
