How can I get an Authentication Token for Microsoft Translator API?

Question

I want to get an Authentication Token for the Microsoft Translator API. This is my code:

<?php

//1. initialize cURL
$ch = curl_init();

//2. set options

//Set to POST request
curl_setopt($ch, CURLOPT_POST,1);

// URL to send the request to
curl_setopt($ch, CURLOPT_URL, 'https://api.cognitive.microsoft.com/sts/v1.0/issueToken');

//return instead of outputting directly
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

//whether to include header in the output. here set to false
curl_setopt($ch, CURLOPT_HEADER, 0);

//pass my subscription key
curl_setopt($ch, CURLOPT_POSTFIELDS,array(Subscription-Key => '<my-key>'));

//CURLOPT_SSL_VERIFYPEER- Set to false to stop verifying certificate
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);

//3. Execute the request and fetch the response. check for errors
$output = curl_exec($ch);

if ($output === FALSE) {
    echo "cURL Error" . curl_error($ch);
}

//4. close and free up the curl handle
curl_close($ch);

//5. display raw output
print_r($output);


?>

it gives me the following error: { "statusCode": 401, "message": "Access denied due to missing subscription key. Make sure to include subscription key when making requests to an API." }

which could mean that the key is invalid according to the website below, but I ensured the key is valid on the same website.

http://docs.microsofttranslator.com/oauth-token.html

I did find some examples online on how to get the Authenticationtoken, but they are outdated.

How can I get the AuthenticationToken/achieve that microsoft recognises my key?

Answer 1

You're passing the subscription-key wrong - The subscription key should passed in the header (Ocp-Apim-Subscription-Key) or as a querystring parameter in the URL ?Subscription-Key=

And you should use Key1 or Key2 generated by the Azure cognitive service dashboard.

FYI - M$ has made a token generator available for testing purposes, this should give you a clue which keys are used for which purpose: http://docs.microsofttranslator.com/oauth-token.html

Here's a working PHP script which translates a string from EN to FR (it's based on an outdated WP plugin called Wp-Slug-Translate by BoLiQuan which I've modified for this purpose):

<?php

define("CLIENTID",'<client-name>'); // client name/id
define("CLIENTSECRET",'<client-key>'); // Put key1 or key 2 here
define("SOURCE","en");
define("TARGET","fr");


class WstHttpRequest
{
	function curlRequest($url, $header = array(), $postData = ''){
		$ch = curl_init();
		curl_setopt($ch, CURLOPT_URL, $url);
		if(!empty($header)){
			curl_setopt($ch, CURLOPT_HTTPHEADER, $header);
		}
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
		curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
		if(!empty($postData)){
			curl_setopt($ch, CURLOPT_POST, TRUE);
			curl_setopt($ch, CURLOPT_POSTFIELDS, is_array($postData) ? http_build_query($postData) : $postData);
		}
		$curlResponse = curl_exec($ch);
		curl_close($ch);
		return $curlResponse;
	}
}

class WstMicrosoftTranslator extends WstHttpRequest
{
	private $_clientID = CLIENTID;
	private $_clientSecret = CLIENTSECRET;
	private $_fromLanguage = SOURCE;
	private $_toLanguage = TARGET;

	private $_grantType = "client_credentials";
	private $_scopeUrl = "http://api.microsofttranslator.com";
	private $_authUrl = "https://api.cognitive.microsoft.com/sts/v1.0/issueToken";
	
	// added subscription-key
	private function _getTokens(){
		try{
			$header = array('Ocp-Apim-Subscription-Key: '.$this->_clientSecret);
			$postData = array(
				'grant_type' => $this->_grantType,
				'scope' => $this->_scopeUrl,
				'client_id' => $this->_clientID,
				'client_secret' => $this->_clientSecret
			);
			$response = $this->curlRequest($this->_authUrl, $header, $postData);
			if (!empty($response))
				return $response;		
		}
		catch(Exception $e){
			echo "Exception-" . $e->getMessage();
		}
	}

	function translate($inputStr){
		$params = "text=" . rawurlencode($inputStr) . "&from=" . $this->_fromLanguage . "&to=" . $this->_toLanguage;
		$translateUrl = "http://api.microsofttranslator.com/v2/Http.svc/Translate?$params";
		$accessToken = $this->_getTokens();
		$authHeader = "Authorization: Bearer " . $accessToken;
		$header = array($authHeader, "Content-Type: text/xml");
		$curlResponse = $this->curlRequest($translateUrl, $header);
		
		$xmlObj = simplexml_load_string($curlResponse);
		$translatedStr = '';
		foreach((array)$xmlObj[0] as $val){
			$translatedStr = $val;
		}
		return $translatedStr;
	}

}

function bing_translator($string) {
	$wst_microsoft= new WstMicrosoftTranslator();
	return $wst_microsoft->translate($string);
}

echo bing_translator("How about translating this?");
?>