// NSString *dataStr = [data objectForKey:@"data"];
    NSData *decodedData = [[NSData alloc] initWithBase64EncodedString:[data objectForKey:@"data"] options:0]; // Take data and base64 decode it to raw bytes

    NSRange sumR = NSMakeRange(decodedData.length - 32, 32); // last 32 bytes are HMAC sum
    NSData *sumData = [decodedData subdataWithRange:sumR]; // split the data to sum
    // NSString *sum = [[NSString alloc] initWithBytes:[sumData bytes] length:[sumData length] encoding: NSUTF8StringEncoding];

    NSRange payloadR = NSMakeRange(0, decodedData.length - 32 - 1); // rest of the data is actual payload, split the data to payload and sum
    NSData *payloadData = [decodedData subdataWithRange:payloadR]; // split the data to payload