Authenticating requests

For an application to be allowed to make calls to the API, it must send a signature with every request. The signature is a JSON string passed in the HTTP Header. It has the following format:

Signature: {
	"AppKey": 12345, 
	"IssuedAt": "yyyyMMddHHmmss", 
	"Token": "hashed string"
}

AppKey is the unique numeric identifier of the application accessing the API. IssuedAt is the UTC timestamp at which the request was initiated. Token is a hashed string built with the following data:

AppKey + HttpMethod + RequestUrl + UtcTimestamp

The concatenated values in Token are a base64 encoded HMAC-SHA256 hash, using AppSecret as the key. Please note that RequestUrl is the complete URL.

If authentication fails, a HTTP status code 401 is returned along with information about the error: see Standard status codes - Bad signature

Example

In order to create a new account, the app must initiate a POST request to:

https://api.dialogportal.com/v1/user

Let us assume the following details:

The application’s AppKey is 32767, and it initiates the request on the 8th of April 2014 at 04:59:51 UTC, so the raw token is:

  32767POSThttps://api.dialogportal.com/v1/user20140408045941

When encrypted using AppSecret RCL1EDAYOVHANLL3A51G, the encrypted token is:

S/3bH3CD44NVM15UpuYds3iJEUp+xicCUZigXpghzaQ=

The complete signature will then look like this:

Signature: {
	"AppKey": 32767,
	"IssuedAt": "20140408045941",
	"Token": "S/3bH3CD44NVM15UpuYds3iJEUp+xicCUZigXpghzaQ="
}

Code Samples

The following code samples will return the encrypted token, using AppSecret as the encryption key

public static string EncryptToken(string secret, string token) { 
	byte[] bytesSecret = Encoding.UTF8.GetBytes(secret); 
	using (var hmacsha256 = new HMACSHA256(bytesSecret)) { 
		byte[] tokenBytes = Encoding.UTF8.GetBytes(token); 
		return Convert.ToBase64String(hmacsha256.ComputeHash(tokenBytes)); 
	}
}

public static function encryptToken($secret,$token)
{
	$token_raw = hash_hmac("sha256", $token, $secret, true);
	return base64_encode($token_raw);
}