Solution to 403 error in PHPCurl _ php instance

This article mainly introduces the solution to the 403 error in PHPCurl, which is a strange error. deleting some CURL parameters can solve this problem, if you need it, you can refer to your own small PHP application and use curl to capture the webpage for processing. in order to make it easy to penetrate the wall, you can use Privoxy as a proxy to select which websites use proxy and which do not need to be used. However, today, we have encountered a strange problem. when visiting google baidu, all these websites actually return the 403 error, but accessing other websites is okay. if it is set to not use proxy, the website can be accessed normally.

Does google baidu prevent proxy connection? Obviously, it is not possible. therefore, open the curl information output (curl_setopt ($ this-> mSh, CURLOPT_VERBOSE, 1);) and see the following result:

The code is as follows:

* Trying 127.0.0.1... * connected
* Connected to 127.0.0.1 (127.0.0.1) port 8118 (#0)
* Establish HTTP proxy tunnel to www.baidu.com: 80
> CONNECT www.baidu.com: 80 HTTP/1.0
Host: www.baidu.com: 80
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)
Proxy-Connection: Keep-Alive

<HTTP/1.0 403 Connection not allowable
<X-Hint: If you read this message interactively, then you know why this happens ,-)
<
* The requested URL returned error: 403
* Canceled Ed HTTP code 403 from proxy after CONNECT
* Closing connection #0
... Failed.

We can see that the proxy server is working normally. it is true that baidu has returned the 403 error, but the reason is definitely on my side. Finally, I got some inspiration from the Internet (1of2, 2of2)-I used proxytunnel instead of proxy.

In the code, there is such a sentence:

The code is as follows:

Curl_setopt ($ this-> mSh, CURLOPT_HTTPPROXYTUNNEL, true );
Curl_setopt ($ this-> mSh, CURLOPT_PROXY, $ phost );

Php documentation does not provide detailed description, but man curl has a detailed explanation. Both are proxies. proxytunnel (-p parameter) allows other protocols to be transmitted through http proxy, while proxy (-x parameter) only http protocol is supported. So I guess that the google baidu server and the curl proxytunnel are inconsistent, so 403 is returned.

After the first sentence of the above two lines of code is disabled, the curl access returns to normal.

It is strange that there are several different operating systems. for a mac osx, you must explicitly disable proxytunnel. the curl version:

The code is as follows:

$ Curl -- version
Curl 7.16.3 (powerpc-apple-darwin9.0) libcurl/7.16.3 OpenSSL/0.9.7l zlib/1.2.3
Protocols: tftp ftp telnet dict ldap http file https ftps
Features: GSS-Negotiate IPv6 Largefile ntlm ssl libz

The other ubuntu is completely unaffected and can be used in any way. curl version:

The code is as follows:

$ Curl -- version
Curl 7.18.2 (i486-pc-linux-gnu) libcurl/7.18.2 OpenSSL/0.9.8g zlib/1.2.3.3 libidn/1.10
Protocols: tftp ftp telnet dict ldap ldaps http file https ftps
Features: GSS-Negotiate IDN IPv6 Largefile ntlm ssl libz

Centos on the MT host is also fine, curl version:

The code is as follows:

$ Curl -- version
Curl 7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5
Protocols: tftp ftp telnet dict ldap http file https ftps
Features: GSS-Negotiate IDN IPv6 Largefile ntlm ssl libz

It seems that it is not entirely about the curl version. mac osx is indeed different.

Another reason is that curl returns the 403 error:

The code is as follows:

Curl_setopt ($ ch, CURLOPT_NOBODY, true );

You need to follow the settings:

The code is as follows:

Curl_setopt ($ ch, CURLOPT_CUSTOMREQUEST, 'Get ');

Otherwise, the 403 error will be returned because the http server does not allow the HEAD command. Reference: Trouble with a cURL request in PHP (http://forums.devshed.com/php-development-5/trouble-with-a-curl-request-in-php-445222.html ). This is the reason why curl is special on mac osx.