DBMS_OBFUSCATION_TOOLKIT.DESdecrypt function returns with some invisible values

Hi,

We are in the process of encrypt/decrypt password file.

I have encrypted the passwords in the file and decrypted the value during our interface process to authenticate to move further and its returning with some invisible values.

I checked the length of the return values it shows in the difference of 4,8 and 16.

I have not seen any values in TOAD, SQL Plus and Unix prompts. But it have some value end of the return value. So because of this authentication failing to move further.

l_decrypt := utl_raw.cast_to_varchar2( hextoraw(trim(l_value1)));

DBMS_OBFUSCATION_TOOLKIT.DESdecrypt (