<body>
<h1 class="title">client.conf(5)</h1>
<h2 class="title"><a name="NAME">Name</a></h2>
-client.conf - client configuration file for cups (deprecated)
+client.conf - client configuration file for cups
<h2 class="title"><a name="DESCRIPTION">Description</a></h2>
The <b>client.conf</b> file configures the CUPS client and is normally located in the <i>/etc/cups</i> and/or <i>~/.cups</i> directories.
Each line in the file can be a configuration directive, a blank line, or a comment. Comment lines start with the # character.
-<p><b>Note:</b> Starting with OS X 10.7, this file is only used by command-line and X11 applications.
-The <b>ServerName</b> directive is not supported on OS X at all.
+<p><b>Note:</b> Starting with macOS 10.7, this file is only used by command-line and X11 applications plus the IPP backend.
+The <b>ServerName</b> directive is not supported on macOS at all.
+Starting with macOS 10.12, all applications can access these settings in the <i>/Library/Preferences/org.cups.PrintingPrefs.plist</i> file instead.
+See the NOTES section below for more information.
<h3><a name="DIRECTIVES">Directives</a></h3>
The following directives are understood by the client. Consult the online help for detailed descriptions:
<dl class="man">
<dt><b>AllowExpiredCerts Yes</b>
<dd style="margin-left: 5.0em"><dt><b>AllowExpiredCerts No</b>
<dd style="margin-left: 5.0em">Specifies whether to allow TLS with expired certificates.
-The default is "Yes".
+The default is "No".
<dt><b>Encryption IfRequested</b>
<dd style="margin-left: 5.0em"><dt><b>Encryption Never</b>
<dd style="margin-left: 5.0em"><dt><b>Encryption Required</b>
<dt><b>ServerName </b><i>hostname-or-ip-address</i>[<i>:port</i>]
<dd style="margin-left: 5.0em"><dt><b>ServerName </b><i>/domain/socket</i>
<dd style="margin-left: 5.0em">Specifies the address and optionally the port to use when connecting to the server.
-<b>Note: This directive it not supported on OS X 10.7 or later.</b>
+<b>Note: This directive it not supported on macOS 10.7 or later.</b>
<dt><b>ServerName </b><i>hostname-or-ip-address</i>[<i>:port</i>]<b>/version=1.1</b>
<dd style="margin-left: 5.0em">Specifies the address and optionally the port to use when connecting to a server running CUPS 1.3.12 and earlier.
+<dt><b>SSLOptions </b>[<i>AllowDH</i>] [<i>AllowRC4</i>] [<i>AllowSSL3</i>] [<i>DenyTLS1.0</i>]
+<dd style="margin-left: 5.0em"><dt><b>SSLOptions None</b>
+<dd style="margin-left: 5.0em">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 <i>AllowDH</i> option enables cipher suites using plain Diffie-Hellman key negotiation.
+The <i>AllowRC4</i> option enables the 128-bit RC4 cipher suites, which are required for some older clients that do not implement newer ones.
+The <i>AllowSSL3</i> option enables SSL v3.0, which is required for some older clients that do not support TLS v1.0.
+The <i>DenyTLS1.0</i> option disables TLS v1.0 support - this sets the minimum protocol version to TLS v1.1.
+<dt><b>TrustOnFirstUse Yes</b>
+<dd style="margin-left: 5.0em"><dt><b>TrustOnFirstUse No</b>
+<dd style="margin-left: 5.0em">Specifies whether to trust new TLS certificates by default.
+The default is "Yes".
<dt><b>User </b><i>name</i>
<dd style="margin-left: 5.0em">Specifies the default user name to use for requests.
<dt><b>ValidateCerts Yes</b>
The default is "No".
</dl>
<h2 class="title"><a name="NOTES">Notes</a></h2>
-The <b>client.conf</b> file is deprecated and will no longer be supported in a future version of CUPS.
+The <b>client.conf</b> 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
+<b>defaults</b>(1)
+command:
+<pre class="man">
+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
+</pre>
+On Linux and other systems using GNU TLS, the <i>/etc/cups/ssl/site.crl</i> file, if present, provides a list of revoked X.509 certificates and is used when validating certificates.
<h2 class="title"><a name="SEE_ALSO">See Also</a></h2>
<a href="man-cups.html?TOPIC=Man+Pages"><b>cups</b>(1),</a>
+<b>default</b>(1),
CUPS Online Help (<a href="http://localhost:631/help">http://localhost:631/help</a>)
<h2 class="title"><a name="COPYRIGHT">Copyright</a></h2>
-Copyright © 2007-2014 by Apple Inc.
+Copyright © 2007-2016 by Apple Inc.
</body>
</html>