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 applica-
tions can access these settings in the /Library/Prefer-
ences/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 on-
line 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 de-
fault 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 authentica-
tion, 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 connect-
ing 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 connect-
ing 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 de-
fault, 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. "Produc-
tOnly" reports "CUPS". "Major" reports "CUPS/major IPP/2". "Mi-
nor" reports "CUPS/major.minor IPP/2.1". "Minimal" reports
"CUPS/major.minor.patch IPP/2.1". "OS" reports "CUPS/major.mi-
nor.path (osname osversion) IPP/2.1". "Full" reports "CUPS/ma-
jor.minor.path (osname osversion; architecture) IPP/2.1". The de-
fault 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 sup-
ported 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 © 2020-2024 by OpenPrinting.
2021-02-28 CUPS client.conf(5)
Generated by dwww version 1.16 on Sat Oct 3 07:40:06 CEST 2026.