function SHA256(input) {
  var rawHash = Utilities.computeDigest(Utilities.DigestAlgorithm.SHA_256, input);
  var txtHash = '';
    for (j = 0; j <rawHash.length; j++) {
   var hashVal = rawHash[j];
    if (hashVal < 0)
      hashVal += 256; 
    if (hashVal.toString(16).length == 1)
      txtHash += "0";
    txtHash += hashVal.toString(16);
  }
    return txtHash;
  }