Test SSL with a self-signed certificate on OSX: https://core.trac.wordpress.org/ticket/34794

test-ssl.php

<?php

$url = 'https://self-signed.badssl.com/';

$handle = curl_init( $url );
curl_setopt( $handle, CURLOPT_SSL_VERIFYPEER, false );
curl_setopt( $handle, CURLOPT_SSL_VERIFYHOST, false );
curl_setopt( $handle, CURLOPT_RETURNTRANSFER, true );
curl_setopt( $handle, CURLOPT_HEADER, false );
$headers = curl_exec( $handle );

if ( $err = curl_errno( $handle ) ) {
	printf( 'Error [%d]: %s' . PHP_EOL, $err, curl_error( $handle ) );
} else {
	echo 'Success!' . PHP_EOL;
	var_dump( $headers );
}