How to enforce md5 function to accept varchar2?

Question

I am trying to use md5 function from dbms_obfuscation_toolkit package.
There are two functions called md5 in that package, the first one accepts one parameter as raw and returns raw whereas the second one accepts one parameter as varchar2 and returns varchar2.
I want to use the second one (varchar2) I tried this code:
declare
v_output varchar2(16);
v_checksum varchar2(16);
v_input varchar2(50) DEFAULT 'SAAD';
begin
v_checksum := dbms_obfuscation_toolkit.md5 (input_string => 'SAAD');
v_output := dbms_obfuscation_toolkit.md5(v_input);
if (v_output = v_checksum) then
dbms_output.put_line('TRUE');
else
dbms_output.put_line('FALSE');
end if;
end;
An eror message appeared:
PLS-00307:too many declarations of 'MD5' match this call
I tried to cast inout_string using cast('SAAD' as varchar2(16)) but it didn't change anything.
How can I enforce md5 function to accept varchar2 and return varchar2

Answer 1

I am getting inproper output if I pass HARBINDER,in uppercase, to md5 and respective put_line does not print the following any output of the line(val1). In word 'Harbinder', what is there which is stopping the interpreter to print. It's strange!
declare
val varchar2(25);
val1 varchar2(25);
input varchar2(15) := 'HARBINDER';
begin
val :=dbms_obfuscation_toolkit.md5(input_string=>input);
val1 :=dbms_obfuscation_toolkit.md5(input_string=>'Harbinder');
dbms_output.put_line('Input: '||input||',Val: '||val|| ',Val1: '|| val1);
end;
OUTPUT:
Input: HARBINDER,Val: ¨
False
What can be the reason?