407 Proxy Authentication Required

HTTP response status code 407 Proxy Authentication Required is a client error that is returned by the server to indicate that the request has to be authenticated for the client to use a proxy. This is similar to a 401 Unauthorized error message, and the user must satisfy the requirements before being allowed access to the resource.

Usage

When the 407 Proxy Authentication Required error message is received, the client understands that valid login credentials need to be supplied in advance of being granted access to the requested resource. This is very similar to the 401 Unauthorized response and the client can use the same authentication protocols.

The Proxy-Authenticate header is returned by the server to indicate what methods it allows.

Example

In the example, the client requests a resource and the server responds with the 407 Proxy Authentication Required response to indicate that the resource is protected. As part of the response, the server indicates that it supports basic authorization. The client responds by stating that it is providing a username:password pair using the basic authentication protocol, which is specified in the Proxy-Authorization header. Finally, the server responds by transmitting the requested resource.

Initial request

GET /documents/tech-news HTTP/1.1
Host: www.example.re

Initial response

HTTP/1.1 407 Proxy Authentication Required
Proxy-Authenticate: Basic; realm=”Documents”

Next request

GET /documents/tech-news HTTP/1.1
Host: www.example.re
Proxy-Authorization: Basic RXhhbXBsZTphaQ==

Final response

HTTP/1.1 200 OK
Content-Type: application/pdf
Content-Length: 25000

<PDF document included in message body>

Code references

.NET

HttpStatusCode.ProxyAuthenticationRequired

Rust

http::StatusCode::PROXY_AUTHENTICATION_REQUIRED

Rails

:proxy_authentication_required

Go

http.StatusProxyAuthRequired

Symfony

Response::HTTP_PROXY_AUTHENTICATION_REQUIRED

Python3.5+

http.HTTPStatus.PROXY_AUTHENTICATION_REQUIRED

Java

java.net.HttpURLConnection.HTTP_PROXY_AUTH

Apache HttpComponents Core

org.apache.hc.core5.http.HttpStatus.SC_PROXY_AUTHENTICATION_REQUIRED

Angular

@angular/common/http/HttpStatusCode.ProxyAuthenticationRequired

Takeaway

The 407 Proxy Authentication Required status code is used to indicate the authorization is required to access the requested resource through a proxy. The server will inform which Authentication method(s) it supports and the client is required to authenticate itself before access is granted. Several common authentication schemes exist.

See also

• 401 Unauthorized
• RFC 7231