Hi all,

For authorization to an endpoint I need a signature based on the HMAC SHA256 encryption. This signature should be created from a query string and a secret key.

I use the following code in apex to create the signature. The problem is that it returns a signature with 44 characters including non alphanumeric characters where I would expect a signature with 64 alphanumeric characters. If I use any of the online HMAC SHA256 converters I get a valid signature with 64 alphanumeric characters.

How can I modify the apex code so I will receive a signature with 64 alphanumeric characters that is complient to '^[A-Fa-f0-9]{64}$'
 

public class generateHmac {

        public static void generateSignature() {
                    DateTime dateTimeNow = dateTime.now();
        String unixTime = ''+dateTimeNow.getTime()/1000;
    string url = 'timestamp=' + unixTime;

string privateKey = 'PRIVATEKEY';


Blob privateKeyBlob = EncodingUtil.base64Decode(privateKey);
//Blob privateKeyBlob = Blob.valueOf(privateKey);
Blob urlBlob = Blob.valueOf(url);
Blob signatureBlob = Crypto.generateMac('HmacSHA256', urlBlob, privateKeyBlob);

String signature =EncodingUtil.base64Encode(signatureBlob);
            
system.debug('signature is ' +signature);

        } 
}