From 672782f0a6fb44943a9288fd87a2169debd00206 Mon Sep 17 00:00:00 2001
From: John Blackbourn <johnbillion@git.wordpress.org>
Date: Wed, 21 Oct 2015 20:37:56 +0000
Subject: [PATCH] Force the REST API URL to use `https` for its scheme when the
 current request is served over HTTPS and the host name matches that of the
 REST API URL.

This allows sites to use an admin area over HTTPS with the front end over HTTP, and not end up with a cross-protocol problem when using the REST API URL in the admin area.

Fixes #34299


git-svn-id: https://develop.svn.wordpress.org/trunk@35342 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/rest-api/rest-functions.php |  7 +++
 tests/phpunit/tests/rest-api.php            | 59 +++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/src/wp-includes/rest-api/rest-functions.php b/src/wp-includes/rest-api/rest-functions.php
index 947efce90e..d80e83985e 100644
--- a/src/wp-includes/rest-api/rest-functions.php
+++ b/src/wp-includes/rest-api/rest-functions.php
@@ -254,6 +254,13 @@ function get_rest_url( $blog_id = null, $path = '/', $scheme = 'rest' ) {
 		$url = add_query_arg( 'rest_route', $path, $url );
 	}
 
+	if ( is_ssl() ) {
+		// If the current host is the same as the REST URL host, force the REST URL scheme to HTTPS
+		if ( $_SERVER['SERVER_NAME'] === parse_url( get_home_url( $blog_id ), PHP_URL_HOST ) ) {
+			$url = set_url_scheme( $url, 'https' );
+		}
+	}
+
 	/**
 	 * Filter the REST URL.
 	 *
diff --git a/tests/phpunit/tests/rest-api.php b/tests/phpunit/tests/rest-api.php
index 93e627428f..64c14625ca 100644
--- a/tests/phpunit/tests/rest-api.php
+++ b/tests/phpunit/tests/rest-api.php
@@ -251,5 +251,64 @@ class Tests_REST_API extends WP_UnitTestCase {
 		update_option( 'permalink_structure', '' );
 		// In non-pretty case, we get a query string to invoke the rest router.
 		$this->assertEquals( 'http://' . WP_TESTS_DOMAIN . '/?rest_route=/', get_rest_url() );
+
 	}
+
+	/**
+	 * @ticket 34299
+	 */
+	public function test_rest_url_scheme() {
+		if ( isset( $_SERVER['HTTPS'] ) ) {
+			$_https = $_SERVER['HTTPS'];
+		}
+		if ( isset( $_SERVER['SERVER_NAME'] ) ) {
+			$_name = $_SERVER['SERVER_NAME'];
+		}
+		$_SERVER['SERVER_NAME'] = parse_url( home_url(), PHP_URL_HOST );
+		$_siteurl = get_option( 'siteurl' );
+
+		// Test an HTTP URL
+		unset( $_SERVER['HTTPS'] );
+		$url = get_rest_url();
+		$this->assertSame( 'http', parse_url( $url, PHP_URL_SCHEME ) );
+
+		// Test an HTTPS URL
+		$_SERVER['HTTPS'] = 'on';
+		$url = get_rest_url();
+		$this->assertSame( 'https', parse_url( $url, PHP_URL_SCHEME ) );
+
+		// Switch to an admin request on a different domain name
+		$_SERVER['SERVER_NAME'] = 'admin.example.org';
+		update_option( 'siteurl', 'http://admin.example.org' );
+		$this->assertNotEquals( $_SERVER['SERVER_NAME'], parse_url( home_url(), PHP_URL_HOST ) );
+
+		set_current_screen( 'edit.php' );
+		$this->assertTrue( is_admin() );
+
+		// Test an HTTP URL
+		unset( $_SERVER['HTTPS'] );
+		$url = get_rest_url();
+		$this->assertSame( 'http', parse_url( $url, PHP_URL_SCHEME ) );
+
+		// Test an HTTPS URL
+		$_SERVER['HTTPS'] = 'on';
+		$url = get_rest_url();
+		$this->assertSame( 'http', parse_url( $url, PHP_URL_SCHEME ) );
+
+		// Reset
+		if ( isset( $_https ) ) {
+			$_SERVER['HTTPS'] = $_https;
+		} else {
+			unset( $_SERVER['HTTPS'] );
+		}
+		if ( isset( $_name ) ) {
+			$_SERVER['SERVER_NAME'] = $_name;
+		} else {
+			unset( $_SERVER['SERVER_NAME'] );
+		}
+		update_option( 'siteurl', $_siteurl );
+		set_current_screen( 'front' );
+
+	}
+
 }