errors with newlines

[drifteaur]

If Element API catches an exception, it will output the exception's message as a HTTP header. The exception message can contain newlines, in which case Yii will print an unhelpful message instead of the exception's message:

PHP Warning 'yii\base\ErrorException' with message 'Header may not contain more than a single header, new line detected' 

in /Users/drifter/www/project/vendor/yiisoft/yii2/web/Response.php:380

Stack trace:
#0 /Users/drifter/www/project/vendor/yiisoft/yii2/web/Response.php(380): ::header()
#1 /Users/drifter/www/project/vendor/yiisoft/yii2/web/Response.php(339): craft\web\Response->sendHeaders()
#2 /Users/drifter/www/project/vendor/yiisoft/yii2/base/Application.php(392): craft\web\Response->send()
#3 /Users/drifter/www/project/web/index.php(86): craft\web\Application->run()
#4 {main}

Proposed resolution: don't include the error message in the header text (it's already included in the content of the returned data). Or, remove the newlines.

It's in DefaultController.php at around line 170.

[brandonkelly]

The only header that Element API is setting is the Content-Type header, via the JsonResponseHeader here:

element-api/src/controllers/DefaultController.php

Lines 101 to 102 in 33da444

	// Set the JSON headers
	(new JsonResponseFormatter())->format($response);

And I just tested locally and couldn’t reproduce. Exception messages are not leaking into the response headers for me. Not sure how that would be happening.

[jlawrence-yellostudio]

@brandonkelly I was just able to replicate this by adding an invalid 'orderBy' to the getElementQuery() in a custom ElementResource class
e.g:

protected function getElementQuery(): ElementQueryInterface
{
        $query = parent::getElementQuery();
        $query->orderBy('boo');
        return $query;
}

[brandonkelly]

What version of PHP are you running? In the case of #138, this ended up being an issue with PHP 7.3.

[drifteaur]

@brandonkelly OK let me clarify, it's not a header like Content-Type, it's the status text sent along with the status code (500 etc).

The caught exception pushes the exception message into the status text; in DefaultController::actionIndex:

    } catch (\Throwable $e) {
        $data = [
            'error' => [
                'code' => $e instanceof HttpException ? $e->statusCode : $e->getCode(),
                'message' => $e->getMessage(),
            ]
        ];
        $statusCode = $e instanceof HttpException ? $e->statusCode : 500;
        $statusText = $e->getMessage();
    }

Later, the response is set:

$response->setStatusCode($statusCode, $statusText);

The Yii Response will set the status code text. If it contains newlines, it will trigger an error.

Proposed resolution: don't include the message in the statusText, it's there in the response body anyway. Or, sanitize it to remove newlines/limit length.

[jlawrence-yellostudio]

@brandonkelly using php7.4 can be replicated using the instructions i provided.

[brandonkelly]

@drifteaur @jlawrence-yellostudio Thanks for the clarification! Just released v2.8.1 with a fix for this.