client.conf man page for CUPS. Copyright 2007-2017 by Apple Inc. Copyright 2006 by Easy Software Products. These coded instructions, statements, and computer programs are the property of Apple Inc. and are protected by Federal copyright law. Distribution and use rights are outlined in the file "LICENSE.txt" which should have been included with this file. If this file is file is missing or damaged, see the license at "http://www.cups.org/".
NAMEclient.conf - client configuration file for cups
DESCRIPTIONThe 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.
DIRECTIVESThe 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".
- 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 ("email@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]
- 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. The AllowDH option enables cipher suites using plain Diffie-Hellman key negotiation. The AllowRC4 option enables the 128-bit RC4 cipher suites, which are required for some older clients that do not implement newer ones. 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.
- 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.
- ValidateCerts Yes
- ValidateCerts No
- Specifies whether to only allow TLS with certificates whose common name matches the hostname. The default is "No".
NOTESThe 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 EncryptionOn 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.