1client.conf(5)                    Apple Inc.                    client.conf(5)
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NAME

6       client.conf - client configuration file for cups
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DESCRIPTION

9       The client.conf file configures the CUPS client and is normally located
10       in the /etc/cups and/or ~/.cups directories.  Each line in the file can
11       be a configuration directive, a blank line, or a comment. Comment lines
12       start with the # character.
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14       Note: Starting with macOS 10.7, this file is only used by  command-line
15       and X11 applications plus the IPP backend.  The ServerName directive is
16       not supported on macOS at all.  Starting with macOS 10.12, all applica‐
17       tions    can    access   these   settings   in   the   /Library/Prefer‐
18       ences/org.cups.PrintingPrefs.plist file instead.  See the NOTES section
19       below for more information.
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21   DIRECTIVES
22       The  following  directives  are  understood  by the client. Consult the
23       online help for detailed descriptions:
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25       AllowAnyRoot Yes
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27       AllowAnyRoot No
28            Specifies whether to allow TLS with  certificates  that  have  not
29            been  signed  by  a trusted Certificate Authority.  The default is
30            "Yes".
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32       AllowExpiredCerts Yes
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34       AllowExpiredCerts No
35            Specifies whether to allow TLS  with  expired  certificates.   The
36            default is "No".
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38       Encryption IfRequested
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40       Encryption Never
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42       Encryption Required
43            Specifies the level of encryption that should be used.
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45       GSSServiceName name
46            Specifies  the  Kerberos service name that is used for authentica‐
47            tion, typically "host", "http", or "ipp".  CUPS  adds  the  remote
48            hostname  ("name@server.example.com") for you. The default name is
49            "http".
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51       ServerName hostname-or-ip-address[:port]
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53       ServerName /domain/socket
54            Specifies the address and optionally the port to use when connect‐
55            ing to the server.  Note: This directive is not supported on macOS
56            10.7 or later.
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58       ServerName hostname-or-ip-address[:port]/version=1.1
59            Specifies the address and optionally the port to use when connect‐
60            ing to a server running CUPS 1.3.12 and earlier.
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62       SSLOptions  [AllowDH]  [AllowRC4]  [AllowSSL3]  [DenyCBC]  [DenyTLS1.0]
63       [MaxTLS1.0] [MaxTLS1.1] [MaxTLS1.2] [MaxTLS1.3] [MinTLS1.0] [MinTLS1.1]
64       [MinTLS1.2] [MinTLS1.3]
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66       SSLOptions None
67            Sets  encryption  options  (only  in  /etc/cups/client.conf).   By
68            default, CUPS only supports encryption using TLS  v1.0  or  higher
69            using  known secure cipher suites.  Security is reduced when Allow
70            options are used.  Security is  enhanced  when  Deny  options  are
71            used.   The  AllowDH  option  enables  cipher  suites  using plain
72            Diffie-Hellman key negotiation (not supported on systems using GNU
73            TLS).   The AllowRC4 option enables the 128-bit RC4 cipher suites,
74            which are required for some older clients.  The  AllowSSL3  option
75            enables SSL v3.0, which is required for some older clients that do
76            not support TLS v1.0.  The DenyCBC option disables all CBC  cipher
77            suites.   The  DenyTLS1.0  option disables TLS v1.0 support - this
78            sets the minimum protocol version to TLS v1.1.  The inTLS  options
79            set the minimum TLS version to support.  The axTLS options set the
80            maximum TLS version to support.  Not all operating systems support
81            TLS 1.3 at this time.
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83       TrustOnFirstUse Yes
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85       TrustOnFirstUse No
86            Specifies  whether  to trust new TLS certificates by default.  The
87            default is "Yes".
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89       User name
90            Specifies the default user name to use for requests.
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92       ValidateCerts Yes
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94       ValidateCerts No
95            Specifies whether to only allow TLS with certificates whose common
96            name matches the hostname.  The default is "No".
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NOTES

99       The  client.conf file is deprecated on macOS and will no longer be sup‐
100       ported in a future version of CUPS.  Configuration settings can instead
101       be viewed or changed using the defaults(1) command:
102       defaults write /Library/Preferences/org.cups.PrintingPrefs.plist Encryption Required
103       defaults write /Library/Preferences/org.cups.PrintingPrefs.plist TrustOnFirstUse -bool NO
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105       defaults read /Library/Preferences/org.cups.PrintingPrefs.plist Encryption
106       On  Linux  and  other systems using GNU TLS, the /etc/cups/ssl/site.crl
107       file, if present, provides a list of revoked X.509 certificates and  is
108       used when validating certificates.
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SEE ALSO

111       cups(1), default(1), CUPS Online Help (http://localhost:631/help)
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114       Copyright © 2007-2017 by Apple Inc.
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1183 November 2017                      CUPS                       client.conf(5)
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