force-localhost-ca

WordPress curl requests (used in wp_remote_get, etc) use an SSL CA cert file in WP Core, not the system PHP default path, or any custom CA you define in php.ini.

Use this drop in plugin (easiest in /wp-content/mu-plugins) to fix the issue on localhost.

Helpful for compatibility with local SSL certs generated by the mkcert command.

Just drop this plugin into /wp-content/mu-plugins and add your custom CA file path to your wp-config.php file like this:

define( 'CUSTOM_LOCAL_CA_CERT', '/Users/exampleuser/Library/Application Support/mkcert/rootCA.pem' );

Three local TLD endings are supported by default: .local, .localhost and .test. If you need additional endings add them to your wp-config.php file like this:

define( 'CUSTOM_LOCAL_CA_TLDS',
	array(
		'localhost',
		'mycrazytld',
		'hyperlocal',
	)
);

thanks

Thanks to @healdev and @Kevinlearynet for initial code and concept for this fix. Original thread: FiloSottile/mkcert#165