From e445660ee3c4aa204a152e0a6dbd250d1896abde Mon Sep 17 00:00:00 2001
From: desrosj <desrosj@git.wordpress.org>
Date: Wed, 14 Apr 2021 23:24:04 +0000
Subject: [PATCH] REST API: Allow authors to read their own password protected
 posts.

Allow authenticated users to read the contents of password protected posts if they have the `edit_post` meta capability for the post.

Props xknown, zieladam, peterwilsoncc, swissspidy, timothyblynjacobs.
Built from https://develop.svn.wordpress.org/trunk@50717


git-svn-id: http://core.svn.wordpress.org/trunk@50326 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 .../class-wp-rest-posts-controller.php        | 61 ++++++++++++++++---
 wp-includes/version.php                       |  2 +-
 2 files changed, 55 insertions(+), 8 deletions(-)

diff --git a/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php b/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
index 775f415dc5..16e3c91edf 100644
--- a/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
+++ b/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
@@ -31,6 +31,14 @@ class WP_REST_Posts_Controller extends WP_REST_Controller {
 	 */
 	protected $meta;
 
+	/**
+	 * Passwordless post access permitted.
+	 *
+	 * @since 5.7.1
+	 * @var int[]
+	 */
+	protected $password_check_passed = array();
+
 	/**
 	 * Constructor.
 	 *
@@ -148,6 +156,38 @@ class WP_REST_Posts_Controller extends WP_REST_Controller {
 		return true;
 	}
 
+	/**
+	 * Override the result of the post password check for REST requested posts.
+	 *
+	 * Allow users to read the content of password protected posts if they have
+	 * previously passed a permission check or if they have the `edit_post` capability
+	 * for the post being checked.
+	 *
+	 * @since 5.7.1
+	 *
+	 * @param bool    $required Whether the post requires a password check.
+	 * @param WP_Post $post     The post been password checked.
+	 * @return bool Result of password check taking in to account REST API considerations.
+	 */
+	public function check_password_required( $required, $post ) {
+		if ( ! $required ) {
+			return $required;
+		}
+
+		$post = get_post( $post );
+
+		if ( ! $post ) {
+			return $required;
+		}
+
+		if ( ! empty( $this->password_check_passed[ $post->ID ] ) ) {
+			// Password previously checked and approved.
+			return false;
+		}
+
+		return ! current_user_can( 'edit_post', $post->ID );
+	}
+
 	/**
 	 * Retrieves a collection of posts.
 	 *
@@ -314,7 +354,7 @@ class WP_REST_Posts_Controller extends WP_REST_Controller {
 
 		// Allow access to all password protected posts if the context is edit.
 		if ( 'edit' === $request['context'] ) {
-			add_filter( 'post_password_required', '__return_false' );
+			add_filter( 'post_password_required', array( $this, 'check_password_required' ), 10, 2 );
 		}
 
 		$posts = array();
@@ -330,7 +370,7 @@ class WP_REST_Posts_Controller extends WP_REST_Controller {
 
 		// Reset filter.
 		if ( 'edit' === $request['context'] ) {
-			remove_filter( 'post_password_required', '__return_false' );
+			remove_filter( 'post_password_required', array( $this, 'check_password_required' ) );
 		}
 
 		$page        = (int) $query_args['paged'];
@@ -445,7 +485,7 @@ class WP_REST_Posts_Controller extends WP_REST_Controller {
 
 		// Allow access to all password protected posts if the context is edit.
 		if ( 'edit' === $request['context'] ) {
-			add_filter( 'post_password_required', '__return_false' );
+			add_filter( 'post_password_required', array( $this, 'check_password_required' ), 10, 2 );
 		}
 
 		if ( $post ) {
@@ -473,8 +513,14 @@ class WP_REST_Posts_Controller extends WP_REST_Controller {
 			return false;
 		}
 
-		// Edit context always gets access to password-protected posts.
-		if ( 'edit' === $request['context'] ) {
+		/*
+		 * Users always gets access to password protected content in the edit
+		 * context if they have the `edit_post` meta capability.
+		 */
+		if (
+			'edit' === $request['context'] &&
+			current_user_can( 'edit_post', $post->ID )
+		) {
 			return true;
 		}
 
@@ -1728,8 +1774,9 @@ class WP_REST_Posts_Controller extends WP_REST_Controller {
 		$has_password_filter = false;
 
 		if ( $this->can_access_password_content( $post, $request ) ) {
+			$this->password_check_passed[ $post->ID ] = true;
 			// Allow access to the post, permissions already checked before.
-			add_filter( 'post_password_required', '__return_false' );
+			add_filter( 'post_password_required', array( $this, 'check_password_required' ), 10, 2 );
 
 			$has_password_filter = true;
 		}
@@ -1767,7 +1814,7 @@ class WP_REST_Posts_Controller extends WP_REST_Controller {
 
 		if ( $has_password_filter ) {
 			// Reset filter.
-			remove_filter( 'post_password_required', '__return_false' );
+			remove_filter( 'post_password_required', array( $this, 'check_password_required' ) );
 		}
 
 		if ( rest_is_field_included( 'author', $fields ) ) {
diff --git a/wp-includes/version.php b/wp-includes/version.php
index fd9143d561..dd8fad9ff4 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.8-alpha-50714';
+$wp_version = '5.8-alpha-50717';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.