cURL base64_encode XML - php

Question

I am trying to cURL a base64_encoded xml string to a c# WebAPI that i dont have control over. I can cURL the string successfully but it is not being accepted by the API.
Logging the output shows that cURL is stripping + characters from the base64 string which i believe to be the problem.
The code i have is:
$username = "username";
$password = "$23hrlkbl";
$xml = "<Envelope><Header><User>".$username."</User><Password>".$password."</Password></Header></Envelope>";
$passThru = "https://api.domain.com/SignIn.aspx?passthruUrl=/Management/Api/DataEnrichment/GetAddresses/?buildingNumber=1%26streetName=Nightingale%20Road%26postcode=L12%200QN
$post_packet_data = 'XMLdataPacket='.urlencode(base64_encode($xml));
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $passThru);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_packet_data);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($ch, CURLOPT_HEADER, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
$response = curl_exec ($ch);
curl_close($ch);
print_r($response);
Posting the following string (non urlencoded $post_packet_data) via an html form to the $passThru address works successfully
XMLdataPacket=PEVudmVsb3BlPjxIZWFkZXI+PFVzZXI+dXNlcm5hbWU8L1VzZXI+PFBhc3N3b3JkPiQyM2hybGtibDwvUGFzc3dvcmQ+PC9IZWFkZXI+PC9FbnZlbG9wZT4=
However when posting the same string via cURL the following is sent and not accepted
XMLdataPacket=PEVudmVsb3BlPjxIZWFkZXI PFVzZXI dXNlcm5hbWU8L1VzZXI PFBhc3N3b3JkPiQyM2hybGtibDwvUGFzc3dvcmQ PC9IZWFkZXI PC9FbnZlbG9wZT4=
UPDATE
After speaking to the developers of the API they have confirmed the requests are now coming in in the correct format but believe the calls are not being processed due to incorrect headers being sent. They have sent me the headers of a working call which they got using fiddler:
POST https://api.domain.com/SignIn.aspx?passthruUrl=/Management/Api/DataEnrichment/GetAddresses/?buildingNumber=1%26streetName=Nightingale%20Road%26postcode=L12%200QN HTTP/1.1
Host: test.domain.com
Connection: keep-alive
Content-Length: 164
Cache-Control: max-age=0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Origin: null
User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.146 Safari/537.36
Content-Type: application/x-www-form-urlencoded
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-GB,en-US;q=0.8,en;q=0.6
Cookie: ASP.NET_SessionId=uzwfjq3zojao3l5fw141l453
XMLdataPacket=PEVudmVsb3BlPjxIZWFkZXI%2BPFVzZXI+dXNlcm5hbWU8L1VzZXI%2BPFBhc3N3b3JkPiQyM2hybGtibDwvUGFzc3dvcmQ%2BPC9IZWFkZXI%2BPC9FbnZlbG9wZT4%3D
How would i amend the headers of the cURL call to replicate the above. Currently again using fiddler the cURL call headers appear as the following:
GET http://test.domain.com/test_call.php HTTP/1.1
Host: test.domain.com
User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:27.0) Gecko/20100101 Firefox/27.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-gb,en;q=0.5
Accept-Encoding: gzip, deflate
Cookie: CAKEPHP=g22d7kf7qs8b1v02uui2mnop30
Authorization: Basic bmV0aG91c2VwcmljZXMxOnRlbXAxODkx
Connection: keep-alive
Cache-Control: max-age=0
The data is receieved at the api end as POST but the curl headers are coming through as GET according to the above

Answer 1

Try using rawurlencode() instead of urlencode() - it encodes the space character using '%20' instead of using the '+' character.