企业代理下CURL摘要认证URI不匹配致400错误的解决咨询

我尝试用curl通过企业代理访问需要摘要认证（Digest Authentication）的远程主机，执行的curl命令如下：

curl -x "http://proxy_username:proxy_pass@proxyIp.xxx.xxx.xxx:8080" -L -X GET "https://remote-host.something.com:443/tomcat_servlet/UploadServlet" --digest -u digest_auth_user:digest_auth_pass -v -k

但收到Apache HTTPD返回的400 Bad Request错误，curl完整输出如下：

*   Trying proxyIp.xxx.xxx.xxx:8080...
* Connected to proxyIp.xxx.xxx.xxx (proxyIp.xxx.xxx.xxx) port 8080 (#0)
* allocate connect buffer
* Establish HTTP proxy tunnel to remote-host.something.com:443
* Proxy auth using Basic with user 'proxy_username'
* Server auth using Digest with user 'digest_auth_user'
> CONNECT remote-host.something.com:443 HTTP/1.1
> Host: remote-host.something.com:443
> Proxy-Authorization: Basic <redacted>
> User-Agent: curl/7.83.1
> Proxy-Connection: Keep-Alive
>
< HTTP/1.1 200 Connection established
< Via:HTTP/1.1 s_proxy_nrt
<
* Proxy replied 200 to CONNECT request
* CONNECT phase completed
* schannel: disabled automatic use of client certificate
* ALPN: offers http/1.1
* ALPN: server did not agree on a protocol. Uses default.
* Server auth using Digest with user 'digest_auth_user'
> GET /tomcat_servlet/UploadServlet HTTP/1.1
> Host: remote-host.something.com
> User-Agent: curl/7.83.1
> Accept: */*
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 307 Temporary Redirect
< Server: Cisco Umbrella
< Date: Tue, 14 Feb 2023 02:52:03 GMT
< Content-Type: text/html
< Content-Length: 190
< Connection: keep-alive
< Set-Cookie: swg_https_a2bc=1; Path=/; Expires=Tue, 14-Feb-23 03:02:03 GMT; domain=remote-host.something.com; SameSite=None; Secure
< Location: https://remote-host.something.com/tomcat_servlet/UploadServlet?swg_a2bc=1
< Via: HTTP/1.1 s_proxy_nrt
<
* Ignoring the response-body
* Connection #0 to host proxyIp.xxx.xxx.xxx left intact
* Issue another request to this URL: 'https://remote-host.something.com/tomcat_servlet/UploadServlet?swg_a2bc=1'
* Found bundle for host: 0x1a0ed47d970 [serially]
* Re-using existing connection #0 with proxy proxyIp.xxx.xxx.xxx
* Connected to proxyIp.xxx.xxx.xxx (proxyIp.xxx.xxx.xxx) port 8080 (#0)
* Server auth using Digest with user 'digest_auth_user'
> GET /tomcat_servlet/UploadServlet?swg_a2bc=1 HTTP/1.1
> Host: remote-host.something.com
> User-Agent: curl/7.83.1
> Accept: */*
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 401 Unauthorized
< Date: Tue, 14 Feb 2023 02:52:03 GMT
< Content-Type: text/html; charset=iso-8859-1
< Content-Length: 381
< Connection: keep-alive
< Server: Apache/2.4.48 (Win64) OpenSSL/1.1.1k
< WWW-Authenticate: Digest realm="https_transfer", nonce="redacted", algorithm=MD5, qop="auth"
< Via: HTTP/1.1 m_proxy_nrt
<
* Ignoring the response-body
* Connection #0 to host proxyIp.xxx.xxx.xxx left intact
* Issue another request to this URL: 'https://remote-host.something.com/tomcat_servlet/UploadServlet?swg_a2bc=1'
* Found bundle for host: 0x1a0ed47d970 [serially]
* Re-using existing connection #0 with proxy proxyIp.xxx.xxx.xxx
* Connected to proxyIp.xxx.xxx.xxx (proxyIp.xxx.xxx.xxx) port 8080 (#0)
* Server auth using Digest with user 'digest_auth_user'
> GET /tomcat_servlet/UploadServlet?swg_a2bc=1 HTTP/1.1
> Host: remote-host.something.com
> Authorization: Digest username="digest_auth_user",realm="https_transfer",nonce="redacted",uri="/tomcat_servlet/UploadServlet?swg_a2bc=1",cnonce="redacted",nc=00000001,algorithm=MD5,response="redacted",qop="redacted"
> User-Agent: curl/7.83.1
> Accept: */*
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 400 Bad Request
< Date: Tue, 14 Feb 2023 02:52:03 GMT
< Content-Type: text/html; charset=iso-8859-1
< Content-Length: 226
< Connection: keep-alive
< Server: Apache/2.4.48 (Win64) OpenSSL/1.1.1k
< Via: HTTP/1.1 m_proxy_nrt
<
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>400 Bad Request</title>
</head><body>
<h1>Bad Request</h1>
<p>Your browser sent a request that this server could not understand.<br />
</p>
</body></html>
* Connection #0 to host proxyIp.xxx.xxx.xxx left intact

服务器端HTTPD日志显示：

[auth_digest:error] [pid 3052:tid 1928] [client xxx.xxx.xxx.xxx:xxx] AH01786: uri mismatch - </tomcat_servlet/UploadServlet?swg_a2bc=1> does not match request-uri </tomcat_servlet/UploadServlet>

原因是curl把代理返回的查询参数加入了认证头的URI中，导致和服务器端的请求URI不匹配。当前HTTPD配置如下：

<Location /tomcat_servlet>
 ProxyPass http://localhost:8080/tomcat_servlet
 ProxyPassReverse http://localhost:8080/tomcat_servlet
 AuthType Digest
 AuthName https_transfer
 AuthUserFile ${SRVROOT}/conf/.htpasswd
 Require valid-user
</Location>

方案一：调整curl命令 #

如果你的curl版本在7.75.0及以上，可以用--digest-uri参数强制指定认证头中的URI为原始路径，忽略跳转后的查询参数：

curl -x "http://proxy_username:proxy_pass@proxyIp.xxx.xxx.xxx:8080" -L -X GET "https://remote-host.something.com:443/tomcat_servlet/UploadServlet" --digest -u digest_auth_user:digest_auth_pass --digest-uri "/tomcat_servlet/UploadServlet" -v -k

若curl版本较低不支持该参数，建议优先升级curl；也可以手动构造Authorization头，但操作繁琐不推荐。

方案二：修改Apache HTTPD配置 #

在<Location>块中添加AuthDigestEnableQueryStringHashing Off，让Apache计算摘要认证时忽略查询字符串：

<Location /tomcat_servlet>
 ProxyPass http://localhost:8080/tomcat_servlet
 ProxyPassReverse http://localhost:8080/tomcat_servlet
 AuthType Digest
 AuthName https_transfer
 AuthUserFile ${SRVROOT}/conf/.htpasswd
 AuthDigestEnableQueryStringHashing Off
 Require valid-user
</Location>

修改后重启Apache服务即可生效。

内容的提问来源于stack exchange，提问作者Mirza Prangon