client.conf(5) — Linux manual page
client.conf(5) Apple Inc. 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 © 2007-2019 by Apple Inc.
COLOPHON
This page is part of the CUPS (a standards-based, open source
printing system) project. Information about the project can be
found at ⟨http://www.cups.org/⟩. If you have a bug report for
this manual page, see ⟨http://www.cups.org/⟩. This page was
obtained from the project's upstream Git repository
⟨https://github.com/apple/cups⟩ on 2024-06-14. (At that time,
the date of the most recent commit that was found in the
repository was 2023-10-27.) If you discover any rendering
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