CORS: PHP: Response to preflight request failed. I allow origin

Question

So I know there are a lot of CORS posts out there and I'm just adding them but I can't find any answers that can help me. So I'm building an Angular 4 application that relies on my php api. Works locally no problem, when I throw it on the domain with the app at app.example.com and the api at api.example.com I am unable to pass my login as I get the following error:

XMLHttpRequest cannot load http://api.example.com/Account/Login. Response to preflight request failed access control check: No 'Access-Control-Allow-Origin' header present in request resource. So source "http://app.example.com" is not allowed access.

我的 php 代码如下所示：

$http_origin = $_SERVER['HTTP_ORIGIN'];

$allowed_domains = array(
    'http://example.com',
    'https://example.com',
    'http://app.example.com',
    'https://app.example.com',
    'http://www.example.com',
    'https://www.example.com'
);

if (in_array(strtolower($http_origin), $allowed_domains))
{  
    // header("Access-Control-Allow-Origin: *");
    header("Access-Control-Allow-Origin: $http_origin");
    header('Access-Control-Allow-Credentials: true');
    header('Access-Control-Max-Age: 86400');
}

// Access-Control headers are received during OPTIONS requests
if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') {
        header("Access-Control-Allow-Methods: GET, POST, OPTIONS");
        header("Access-Control-Allow-Headers: Authorization, Content-Type,Accept, Origin");
    exit(0);
}

我的 Angular 帖子如下所示：

public login(login: Login): Observable<LoginResponse> {
    let headers = new Headers();
    headers.append('Content-Type', 'application/x-www-form-urlencoded');
    headers.append('Authorization', 'Basic '   btoa(login.Username   ':'   login.Password));
    return  this.http.post(this.apiBaseUrl   '/Account/Login', "grant_type=client_credentials", { headers: headers })
        .map(response => {
            // code
        });
}

如果我通过邮递员运行请求（这不会影响 CORS），我会得到：

{ "error": "invalid_client", "error_description": "Client credentials were not found in the headers or body" }

我尝试将 origin 设置为 '*' 只是为了测试并查看这是否是问题的核心，但它仍然以同样的方式失败。

编辑 只是根据以下信息进行更新。更改标头中的大小写没有任何效果，并且从 if 语句中提取代码也没有任何效果。

我通过告诉我的实时应用程序转到本地 api 来调试 php，并且 php 正在按预期工作。它设置标头并将其放入每个 if 语句中。

编辑镜头 2 我确实需要一些帮助，如果有人有任何想法，我将非常感激。

Edit Shot 3 If I set all the header stuff in .htaccess instead of php it lets me pass. However, now I'm stuck with the error listed above, which is the error I always get when using Postman, but now when using the actual website.

{"error":"invalid_client","error_description":"Client credentials not found in header or body"}

My response headers look like this

Access-Control-Allow-Credentials:true
Access-Control-Allow-Headers:authorization, content-type, accept, origin
Access-Control-Allow-Methods:GET, POST, OPTIONS
Access-Control-Allow-Origin:*

Once it's working I'll change it from * to just my domain. But now I leave it as *.

My header upon request.

Answer 1

In my similar case, Angular frontend and Php backend helped with the code below. First I send a header:

header("Access-Control-Allow-Origin: http://localhost:4200");   
header("Content-Type: application/json; charset=UTF-8");    
header("Access-Control-Allow-Methods: POST, DELETE, OPTIONS");    
header("Access-Control-Max-Age: 3600");    
header("Access-Control-Allow-Headers: Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With");

After them I can ignore option requests:

if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {    
   return 0;    
}

This approach helped me handle "post" and "delete" embedded request methods in Angular.

Answer 2

Well, I had a similar problem recently and I solved it all on the backend only, without the .htaccess stuff.

When the browser sends a cross-server request, it first sends an OPTIONS request to ensure that it is valid and that a "real" request can be sent. The "real" request is sent when it gets a correct and valid response from OPTIONS.

Now, for both requests to the backend, you need to make sure the correct headers are returned: content-type, allow-origin, allow-headers, etc...

Ensure that in the OPTIONS request on the backend, the application returns the header and returns the response instead of continuing the full flow of the application.

In a "real" request you should return the correct headers and regular response body.

Example:

//The Response object
    $res = $app->response;

    $res->headers->set('Content-Type', 'application/json');
    $res->headers->set('Access-Control-Allow-Origin', 'http://example.com');
    $res->headers->set('Access-Control-Allow-Credentials', 'true');
    $res->headers->set('Access-Control-Max-Age', '60');
    $res->headers->set('Access-Control-Allow-Headers', 'AccountKey,x-requested-with, Content-Type, origin, authorization, accept, client-security-token, host, date, cookie, cookie2');
    $res->headers->set('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS');

    if ( ! $req->isOptions()) {
        // this continues the normal flow of the app, and will return the proper body
        $this->next->call();
    } else {
        //stops the app, and sends the response
        return $res;
    }

Things to remember:

• If you use: "Access-Control-Allow-Credentials" = true Make sure "Access-Control-Allow-Origin" is not "*", it must be set to the correct domain! (A lot of blood was shed here :/)

• Define the allow headers you will get in "Access-Control-Allow-Headers" If you don't define them, the request will fail

• If you use "Authorization: Bearer", then "Access-Control-Allow-Headers" should also contain "Authorization", otherwise the request will fail