Webservice works through curl command line but not PHP

Question

I'm trying to translate a curl command I was given into a command I can run through PHP.

The command is:

curl -F customerid=902 -F username=API1 -F password=somepassword -F reportname=1002 http://somerandomurl.com/api/v1/getreportcsv

When I try to run this through PHP (and eventually through C#) however, the web service returns an error. Any idea what could be wrong with my code that is making it error? I think the web service must be very specific about the headers/request:

$url = "http://somerandomurl.com/api/v1/getreportcsv";
$fields = [
  "customerid" => "902",
  "username"   => "API1",
  "password"   => "somepassword",
  "reportname" => "1002"
];

$fields_string = "";
foreach($fields as $key=>$value) { $fields_string .= $key.'='.$value.'&'; }
rtrim($fields_string,'&');

//open connection
$ch = curl_init();

curl_setopt($ch,CURLOPT_URL,$url);
curl_setopt($ch,CURLOPT_POST,count($fields));
curl_setopt($ch,CURLOPT_POSTFIELDS,$fields_string);

//execute post
$result = curl_exec($ch);
print $result;

Wireshark shows the following differences:

The below is the one that works:

POST /somefolder/api/v1/getreportcsv HTTP/1.1
Host: somehost
Accept: */*
Content-Length: 65
Content-Type: application/x-www-form-urlencoded

customerid=902&username=API1&password=somepassword&reportname=1002&HTTP/1.1 200 OK
Server: GlassFish Server Open Source Edition 3.1.1
Content-Type: text/html;charset=UTF-8
Content-Length: 6
Date: Thu, 26 Nov 2015 22:51:23 GMT

ERROR 

Whereas this one works:

POST /someurl/api/v1/getreportcsv HTTP/1.1
User-Agent: curl/7.33.0
Host: somehost
Accept: */*
Content-Length: 459
Expect: 100-continue
Content-Type: multipart/form-data; boundary=------------------------4b0d14cc31a40c5b

HTTP/1.1 100 Continue

--------------------------4b0d14cc31a40c5b
Content-Disposition: form-data; name="customerid"

902
--------------------------4b0d14cc31a40c5b
Content-Disposition: form-data; name="username"

API1
--------------------------4b0d14cc31a40c5b
Content-Disposition: form-data; name="password"

somepassword
--------------------------4b0d14cc31a40c5b
Content-Disposition: form-data; name="reportname"

1002
--------------------------4b0d14cc31a40c5b--
HTTP/1.1 200 OK
Server: GlassFish Server Open Source Edition 3.1.1
Content-Type: text/html;charset=UTF-8
Transfer-Encoding: chunked
Date: Thu, 26 Nov 2015 23:13:57 GMT

2000
...snip... the results of the api

Obviously they are very different requests, however I wouldn't expect something to be so specific?

Answer 1

The question seems very specific to the service in question.

However, the problem might be with headers. According to curl man page :

-F [...] causes curl to POST data using the Content-Type multipart/form-data according to RFC 2388

However, according to PHP manual , CURLOPT_POST option will send data using application/x-www-form-urlencoded .

According to the same manual, if value of CURLOPT_POSTFIELDS is an array, the Content-Type header will be set to multipart/form-data . You may also try to set the content type explicitly as a header.

Try setting the following cURL options:

curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POST, count($fields));
curl_setopt($ch, CURLOPT_POSTFIELDS, $fields);
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-type: multipart/form-data'));

If that does not work, it might help analysing all the headers send by the command line curl using the -v parameter and try to set them. Also might be good idea to set content length header explicitly.