2.5. Excluding an application from following system-wide crypto policies
You can customize cryptographic settings used by your application by configuring supported cipher suites and protocols directly in the application.
You can also remove a symlink related to your application from the /etc/crypto-policies/back-ends directory and replace it with your customized cryptographic settings. This configuration prevents the use of system-wide cryptographic policies for applications that use the excluded back end. Furthermore, this modification is not supported by Red Hat.
2.5.1. Examples of opting out of system-wide crypto policies 링크 복사링크가 클립보드에 복사되었습니다!
- curl
To specify ciphers used by the
curltool, use the--ciphersoption and provide a colon-separated list of ciphers as a value. For example:$ curl <https://example.com> --ciphers '@SECLEVEL=0:DES-CBC3-SHA:RSA-DES-CBC3-SHA'See the
curl(1)man page for more information.- Libreswan
- See the Enabling legacy ciphers and algorithms in Libreswan section in the Securing networks document for detailed information.
- Mozilla Firefox
-
Even though you cannot opt out of system-wide cryptographic policies in the Mozilla Firefox web browser, you can further restrict supported ciphers and TLS versions in the Firefox’s Configuration Editor. Type
about:configin the address bar and change the value of thesecurity.tls.version.minoption as required. Settingsecurity.tls.version.minto1allows TLS 1.0 as the minimum required,security.tls.version.min 2enables TLS 1.1, and so on. - OpenSSH server
To opt out of the system-wide cryptographic policies for your OpenSSH server, specify the cryptographic policy in a drop-in configuration file located in the
/etc/ssh/sshd_config.d/directory. Use a two-digit number prefix smaller than 50, so that it lexicographically precedes the50-redhat.conffile, and a.confsuffix, for example,49-crypto-policy-override.conf.See the
sshd_config(5)man page for more information.- OpenSSH client
To opt out of system-wide cryptographic policies for your OpenSSH client, perform one of the following tasks:
-
For a given user, override the global
ssh_configwith a user-specific configuration in the~/.ssh/configfile. -
For the entire system, specify the cryptographic policy in a drop-in configuration file located in the
/etc/ssh/ssh_config.d/directory, with a two-digit number prefix smaller than 50, so that it lexicographically precedes the50-redhat.conffile, and with a.confsuffix, for example,49-crypto-policy-override.conf.
See the
ssh_config(5)man page for more information.-
For a given user, override the global
- wget
To customize cryptographic settings used by the
wgetnetwork downloader, use the--secure-protocoland--ciphersoptions. For example:$ wget --secure-protocol=TLSv1_1 --ciphers="SECURE128" <https://example.com>See the HTTPS (SSL/TLS) Options section of the
wget(1)man page for more information.