abinitio cant decode encoded sha256 value

Question

I can encode a decimal value in abinitio but I can not decode the hashed value. I have some files that keep only hashed values, I want to decode them and later on join them based on decoded values.

val 286016254358153

valHash f5JKPD2ZpFvlDEu7cjMQ97aw354yGhcP5/CoRVKsDhI=

out :: reformat(in) =
begin
  out.val :: in.val;
  out.valHash :: string_replace(encode_base64(hash_SHA256(in.val)),'\n','');
  out.* :: in.*;
end;

I am trying to decode like this but it gets NULL values. I appreciate any help.

out :: reformat(in) =
begin
  out.val :: in.val;
  out.valHash :: in.valHash;
  out.decodevalHash ::(decimal("¨"))  decode_base64(hash_SHA256( string_concat(in.valHash, "\n"))); 
   out.* :: in.*;
end;