3 files changed, 120 insertions, 5 deletions
diff --git a/phpBB/includes/functions.php b/phpBB/includes/functions.php
index ba448f3125..84178f74e4 100644
--- a/phpBB/includes/functions.php
+++ b/phpBB/includes/functions.php
@@ -3442,6 +3442,11 @@ function get_preg_expression($mode)
 		case 'path_remove_dot_trailing_slash':
 			return '#^(?:(\.)?)+(?:(.+)?)+(?:([\\/\\\])$)#';
 		break;
+
+		case 'semantic_version':
+			// Regular expression to match semantic versions by http://rgxdb.com/
+			return '/(?<=^[Vv]|^)(?:(?<major>(?:0|[1-9](?:(?:0|[1-9])+)*))[.](?<minor>(?:0|[1-9](?:(?:0|[1-9])+)*))[.](?<patch>(?:0|[1-9](?:(?:0|[1-9])+)*))(?:-(?<prerelease>(?:(?:(?:[A-Za-z]|-)(?:(?:(?:0|[1-9])|(?:[A-Za-z]|-))+)?|(?:(?:(?:0|[1-9])|(?:[A-Za-z]|-))+)(?:[A-Za-z]|-)(?:(?:(?:0|[1-9])|(?:[A-Za-z]|-))+)?)|(?:0|[1-9](?:(?:0|[1-9])+)*))(?:[.](?:(?:(?:[A-Za-z]|-)(?:(?:(?:0|[1-9])|(?:[A-Za-z]|-))+)?|(?:(?:(?:0|[1-9])|(?:[A-Za-z]|-))+)(?:[A-Za-z]|-)(?:(?:(?:0|[1-9])|(?:[A-Za-z]|-))+)?)|(?:0|[1-9](?:(?:0|[1-9])+)*)))*))?(?:[+](?<build>(?:(?:(?:[A-Za-z]|-)(?:(?:(?:0|[1-9])|(?:[A-Za-z]|-))+)?|(?:(?:(?:0|[1-9])|(?:[A-Za-z]|-))+)(?:[A-Za-z]|-)(?:(?:(?:0|[1-9])|(?:[A-Za-z]|-))+)?)|(?:(?:0|[1-9])+))(?:[.](?:(?:(?:[A-Za-z]|-)(?:(?:(?:0|[1-9])|(?:[A-Za-z]|-))+)?|(?:(?:(?:0|[1-9])|(?:[A-Za-z]|-))+)(?:[A-Za-z]|-)(?:(?:(?:0|[1-9])|(?:[A-Za-z]|-))+)?)|(?:(?:0|[1-9])+)))*))?)$/';
+		break;
 	}
 
 	return '';
diff --git a/phpBB/language/en/acp/common.php b/phpBB/language/en/acp/common.php
index 88e60d00a3..9d2723ceb3 100644
--- a/phpBB/language/en/acp/common.php
+++ b/phpBB/language/en/acp/common.php
@@ -417,11 +417,14 @@ $lang = array_merge($lang, array(
 	'UPLOAD_DIR_SIZE'	=> 'Size of posted attachments',
 	'USERS_PER_DAY'		=> 'Users per day',
 
-	'VALUE'						=> 'Value',
-	'VERSIONCHECK_FAIL'			=> 'Failed to obtain latest version information.',
-	'VERSIONCHECK_FORCE_UPDATE'	=> 'Re-Check version',
-	'VIEW_ADMIN_LOG'			=> 'View administrator log',
-	'VIEW_INACTIVE_USERS'		=> 'View inactive users',
+	'VALUE'							=> 'Value',
+	'VERSIONCHECK_FAIL'				=> 'Failed to obtain latest version information.',
+	'VERSIONCHECK_FORCE_UPDATE'		=> 'Re-Check version',
+	'VERSIONCHECK_INVALID_ENTRY'	=> 'Latest version information contains an unsupported entry.',
+	'VERSIONCHECK_INVALID_URL'		=> 'Latest version information contains invalid URL.',
+	'VERSIONCHECK_INVALID_VERSION'	=> 'Latest version information contains an invalid version.',
+	'VIEW_ADMIN_LOG'				=> 'View administrator log',
+	'VIEW_INACTIVE_USERS'			=> 'View inactive users',
 
 	'WELCOME_PHPBB'			=> 'Welcome to phpBB',
 	'WRITABLE_CONFIG'		=> 'Your config file (config.php) is currently world-writable. We strongly encourage you to change the permissions to 640 or at least to 644 (for example: <a href="http://en.wikipedia.org/wiki/Chmod" rel="external">chmod</a> 640 config.php).',
diff --git a/phpBB/phpbb/version_helper.php b/phpBB/phpbb/version_helper.php
index a1e66ba8fe..dc95f6d001 100644
--- a/phpBB/phpbb/version_helper.php
+++ b/phpBB/phpbb/version_helper.php
@@ -61,6 +61,23 @@ class version_helper
 	/** @var \phpbb\user */
 	protected $user;
 
+	protected $version_schema = array(
+		'stable' => array(
+			'current'		=> 'version',
+			'download'		=> 'url',
+			'announcement'	=> 'url',
+			'eol'			=> 'url',
+			'security'		=> 'bool',
+		),
+		'unstable' => array(
+			'current'		=> 'version',
+			'download'		=> 'url',
+			'announcement'	=> 'url',
+			'eol'			=> 'url',
+			'security'		=> 'bool',
+		),
+	);
+
 	/**
 	 * Constructor
 	 *
@@ -298,9 +315,99 @@ class version_helper
 			$info['stable'] = (empty($info['stable'])) ? array() : $info['stable'];
 			$info['unstable'] = (empty($info['unstable'])) ? $info['stable'] : $info['unstable'];
 
+			$this->validate_versions($info);
+
 			$this->cache->put($cache_file, $info, 86400); // 24 hours
 		}
 
 		return $info;
 	}
+
+	/**
+	 * Validate versions info input
+	 *
+	 * @param array $versions_info Decoded json data array. Will be modified
+	 *		and cleaned by this method
+	 */
+	public function validate_versions(&$versions_info)
+	{
+		$array_diff = array_diff_key($versions_info, array($this->version_schema));
+
+		// Remove excessive data
+		if (count($array_diff) > 0)
+		{
+			$old_versions_info = $versions_info;
+			$versions_info = array(
+				'stable'	=> !empty($old_versions_info['stable']) ? $old_versions_info['stable'] : array(),
+				'unstable'	=> !empty($old_versions_info['unstable']) ? $old_versions_info['unstable'] : array(),
+			);
+			unset($old_versions_info);
+		}
+
+		foreach ($versions_info as $stability_type => &$versions_data)
+		{
+			foreach ($versions_data as $branch => &$version_data)
+			{
+				if (!preg_match('/^[0-9]+\.[0-9]+$/', $branch))
+				{
+					unset($versions_data[$branch]);
+					continue;
+				}
+
+				$stability_diff = array_diff_key($version_data, $this->version_schema[$stability_type]);
+
+				if (count($stability_diff) > 0)
+				{
+					$old_version_data = $version_data;
+					$version_data = array();
+					foreach ($this->version_schema[$stability_type] as $key => $value)
+					{
+						if (isset($old_version_data[$key]) || $old_version_data[$key] === null)
+						{
+							$version_data[$key] = $old_version_data[$key];
+						}
+					}
+					unset($old_version_data);
+				}
+
+				foreach ($version_data as $key => &$value)
+				{
+					if (!isset($this->version_schema[$stability_type][$key]))
+					{
+						unset($version_data[$key]);
+						throw new \RuntimeException($this->user->lang('VERSIONCHECK_INVALID_ENTRY'));
+					}
+
+					switch ($this->version_schema[$stability_type][$key])
+					{
+						case 'bool':
+							$value = (bool) $value;
+						break;
+
+						case 'url':
+							if (!empty($value) && !preg_match('#^' . get_preg_expression('url') . '$#iu', $value) &&
+								!preg_match('#^' . get_preg_expression('www_url') . '$#iu', $value))
+							{
+								$value = '';
+								throw new \RuntimeException($this->user->lang('VERSIONCHECK_INVALID_URL'));
+							}
+						break;
+
+						case 'version':
+							$value = $value ?: '';
+							if (!preg_match(get_preg_expression('semantic_version'), $value))
+							{
+								$value = '';
+								throw new \RuntimeException($this->user->lang('VERSIONCHECK_INVALID_VERSION'));
+							}
+						break;
+
+						default:
+							// Shouldn't be possible to trigger this
+							throw new \RuntimeException($this->user->lang('VERSIONCHECK_INVALID_ENTRY'));
+					}
+				}
+			}
+		}
+	}
 }