Convert NVARCHAR2 to MD5 Hash in Oracle DBMS_OBFUSCATION_TOOLKIT.MD5

Question

DECLARE
  l_string  NVARCHAR2(600) := '123456';
  checksum  NVARCHAR2(600);

BEGIN

   DBMS_OUTPUT.DISABLE;
   DBMS_OUTPUT.ENABLE(1000000);

   DBMS_OBFUSCATION_TOOLKIT.md5 (input_string  => l_string, checksum_string => checksum);

   DBMS_OUTPUT.PUT_LINE(RAWTONHEX(utl_raw.cast_to_raw(checksum)));

END;

Expected value: e10adc3949ba59abbe56e057f20f883e

But it returns: FFFD00390049FFFD0059FFFDFFFD0056FFFD000FFFFD003E

Note I want to maintain nvarchar2 datatype. The value from checksum variable gets stored in column that is of type nvarchar2.

I am aware that md5 accepts and returns data in varchar2. But if someone can help me figure this out using nvarchar2 data type, that would be great.

The NLS_CHARACTERSET = AL32UTF8

Answer 1

The following should work via dbms_crypto using hash()

declare
  l_src nvarchar2(100) := '123456';
  l_raw_hash raw(100);
begin
  l_raw_hash := dbms_crypto.hash(to_clob(l_src), dbms_crypto.HASH_MD5);
  dbms_output.put_line(l_raw_hash);
end;

Result: E10ADC3949BA59ABBE56E057F20F883E

l_raw_hash will be in raw format. You can use UTL_RAW to convert it to another datat type. Just make sure your display is showing the proper character set or thing will look interesting.