Access Exchange Web Services with PHP and cURL - php

Question

Hello,
I am currently writing a client to access a Microsoft Exchange server and read contacts, appointments etc. from it.
Through days of searching I've been able to connect to the EWS via PHP's Soap client and a custom HTTPS Stream wrapper. This website helped me greatly at this point.
Everything worked fine on my Windows 7 machine using XAMPP
Now I uploaded my project to a Debian 6.0 Squeeze development machine that has exactly the same configuration as my Windows machine regarding the web-server, php settings, mysql settings etc. but it just wont work anymore
The debian machine can resolve and ping the exchange server without problems
I nailed the actual problem down to a point, where cURL isn't able to retrieve the WSDL file of the EWS
It always receives an empty response and a 401 (Unauthorized) status code
The credentials I use are correct, the same credentials work on my windows machine
I extracted the faulty piece of code and tried running it stand-alone, it looks like this:
echo "Trying to get https://".$cfg[ 'Exchange.Server' ]."/EWS/Services.wsdl<br>";
$curl = curl_init( 'https://'.$cfg[ 'Exchange.Server' ].'/EWS/Services.wsdl' );
curl_setopt( $curl, CURLOPT_RETURNTRANSFER, true );
curl_setopt( $curl, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1 );
curl_setopt( $curl, CURLOPT_HTTPAUTH, CURLAUTH_NTLM );
curl_setopt( $curl, CURLOPT_USERPWD, $cfg[ 'Exchange.User' ].':'.$cfg[ 'Exchange.Password' ] );
curl_setopt( $curl, CURLOPT_SSL_VERIFYPEER, false );
curl_setopt( $curl, CURLOPT_SSL_VERIFYHOST, false );
echo '<pre>';
$response = curl_exec( $curl );
$info = curl_getinfo( $curl );
var_dump( $info );
var_dump( $response );
curl_close( $curl );
The result I receive here is the mentioned 401 status code and an empty response
When I call the same url in my browser or with the same code on my windows machine, I get the WSDL file I want
Actually I can't even tell if this is a linux-based problem or if I do something wrong at some point, I'm struggling with this for 2 days now.
Is there someone that may be able to find my mistake or tell me the reason why it doesn't work?
I may provide any further needed information on demand

Answer 1

If you initialize your soap client properly, you should be able to preform any requests requests this way:
$curl = curl_init($location); //'https://'.$server_address.'/EWS/Exchange.asmx'
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers); //valid soap headers with keep-alive
curl_setopt($ch, CURLOPT_POST, true );
curl_setopt($ch, CURLOPT_POSTFIELDS, $request);
curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
curl_setopt($ch, CURLOPT_USERPWD, $user.':'.$password);
$response = curl_exec($curl);
As to your code, try commenting out following line:
curl_setopt( $curl, CURLOPT_HTTPAUTH, CURLAUTH_NTLM );
Also take a look wherever this wrapper works on your setup:
http://ewswrapper.lafiel.net/
If it does, take a look at SOAP classes used there - it uses php built-in as base.
Why can't you store wsdl file locally anyways?
UPDATE:
Ok, I played around with this in my Debian box and this works for me flawlessly:
$domain = 'xxxxxx';
$user = 'xxxxxx';
$password = 'xxxxxx';
$ch = curl_init('https://'.$domain.'/EWS/Services.wsdl');
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
curl_setopt($ch, CURLOPT_USERPWD, $user.':'.$password);
$response = curl_exec($ch);
$info = curl_getinfo( $ch );
$error = curl_error ($ch);
print_r(array($response,$info,$error));
returns
Array
(
[0] => <?xml version="1.0" encoding="utf-8"?>
<wsdl:definitions
(...)
</wsdl:definitions>
[1] => Array
(
[url] => xxxxx/EWS/Services.wsdl
[content_type] => text/xml
[http_code] => 200
[header_size] => 250
[request_size] => 147
[filetime] => -1
[ssl_verify_result] => 0
[redirect_count] => 0
[total_time] => 0.60574
[namelookup_time] => 0.165249
[connect_time] => 0.268173
[pretransfer_time] => 0.474009
[size_upload] => 0
[size_download] => 55607
[speed_download] => 91800
[speed_upload] => 0
[download_content_length] => 55607
[upload_content_length] => 0
[starttransfer_time] => 0.580931
[redirect_time] => 0
[certinfo] => Array
(
)
[redirect_url] =>
)
[2] =>
)

Answer 2

Your first check should not use any complex scripting.
Instead try opening the WDSL from a simple browser window on the Debian machine like so:
https://your.exchange-server.com/EWS/Services.wsdl
If that does not work there are probably access restrictions in place that depend on the client IP or client network (e.g. your development machine being in a trusted network, your Debian not). The fact that you get a 401 ("Unauthorized" - request requires user authentication) suggests that there is no problem with contacting the server but with authentication.
Another check I suggest is that you have a look into your phpinfo() to make sure your PHP installation on Debian is capable of handling HTTP*S* requests. Make sure, OpenSSL is installed!

Answer 3

This article helped point me in the right direction. One thing to keep in mind is that
your PHP installation may not be sharing your system's cURL / libcurl setup.
http://blog.ianty.com/ubuntu/exchange-web-services-ews-ntlmv2-and-linux/