代理授权失败的HTTP响应码

Question

代理授权失败的HTTP响应代码应该是什么？我知道407是请求代理授权的响应码。但是，一旦客户端将身份验证信息发送到代理，并且如果它是不正确的，代理应该返回什么？如果它返回401响应码，那么客户端如何识别它是代理上的身份验证失败，而不是终端资源上的身份验证失败？

Answer 1

好吧，如果一个受401保护的资源出现授权失败，服务器会简单地返回另一个401：

Request URL:https://mysite.com/myresource/
Request Method:GET
Status Code:401 Authorization Required

Request Headers

Accept:text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Charset:ISO-8859-1,utf-8;q=0.7,*;q=0.3
Accept-Encoding:gzip,deflate,sdch
Accept-Language:en-US,en;q=0.8
Authorization:Digest username="gjggj", realm="apps", nonce="75602afa895d26f9796f3c9174cf83f3", uri="/misc/apps/", algorithm=MD5, response="9e113b10d3e95b590bdef0fc7c7c617b", qop=auth, nc=00000001, cnonce="61f73b73f6b33ea2"
Cache-Control:max-age=0
Connection:keep-alive
Host:game-point.net
User-Agent:Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.57 Safari/537.17

Response Headers

Cache-Control:no-cache
Connection:close
Content-Length:534
Content-Type:text/html
Date:Wed, 13 Feb 2013 11:07:26 GMT
Pragma:no-cache
Server:Cherokee/1.0.8 (Debian GNU/Linux)
WWW-Authenticate:Digest realm="apps", nonce="75602afa895d26f9796f3c9174cf83f3", qop="auth", algorithm="MD5"

所以我要说的是，处理407授权失败的方法是让服务器响应407状态代码，尽管浏览器已经发送了授权信息；这表明代理仍然需要授权，并暗示授权失败只是因为您仍然获得407状态代码。

Answer 2

来自官方机构：

http://www.ietf.org/rfc/rfc2617.txt

If the origin server does not wish to accept the credentials sent
with a request, it SHOULD return a 401 (Unauthorized) response. The
response MUST include a WWW-Authenticate header field containing at
least one (possibly new) challenge applicable to the requested
resource. If a proxy does not accept the credentials sent with a
request, it SHOULD return a 407 (Proxy Authentication Required). The
response MUST include a Proxy-Authenticate header field containing a
(possibly new) challenge applicable to the proxy for the requested
resource.