Encrypt (& decrypt) a number column in Oracle - oracle

Question

How to do for encrypting a number
column in Oracle 11 (and also be able to decrypt them back) so that the same column stores crypted numbers along with (unencrypted ones (based on a boolean saved elsewhere)?
I actually did a function like this that takes a number to produce a crypted number and it worked fine in Oracle 10 but now it doesn't work anymore in ORACLE 11:
function crypt (key varchar2, n number) return number
raw_input RAW(128);
encrypted_raw RAW(2048);
raw_key_ RAW(128) := UTL_RAW.CAST_TO_RAW(CONVERT(key,'AL32UTF8','US7ASCII'));
begin
raw_input_ := UTL_RAW.cast_from_number (n);
encrypted_raw := dbms_crypto.Encrypt(src => raw_input_, typ =>DBMS_CRYPTO.DES3_CBC_PKCS5, KEY=>raw_key_);
return UTL_RAW.cast_to_number(encrypted_raw);
end;
it throws this error with no explanations:
ORA-06502: PL/SQL: numeric or value error
ORA-06512: at "SYS.UTL_RAW", line 388
...
Thank you

Answer 1

Looks like you're trying to cast the encrypted raw to a number. If I understand what you want this function to do, it seems you want to test that the input number = returned number (that you can encrypt and decrypt successfully). If you wanted to just encrypt, you would return a raw, not a number.
Anyway, you should be casting the decrypted raw value to a number to test that the input number = returned number. Something like:
create or replace function test_crypt(k varchar2, n number)
return number as
raw_input_ RAW(128);
encrypted_raw RAW(2000);
decrypted_raw RAW (2000);
raw_key_ RAW(128) := UTL_RAW.CAST_TO_RAW(k);
begin
raw_input_ := UTL_RAW.cast_from_number (n);
encrypted_raw := dbms_crypto.Encrypt(src => raw_input_, typ =>DBMS_CRYPTO.DES3_CBC_PKCS5, KEY=>raw_key_);
--return UTL_RAW.cast_to_number(encrypted_raw);
-- use dbms_crypto to decrypt and return (hopefully same) number
decrypted_raw := DBMS_CRYPTO.DECRYPT
(
src => encrypted_raw,
typ => DBMS_CRYPTO.DES3_CBC_PKCS5,
key => raw_key_
);
return UTL_RAW.cast_to_number(decrypted_raw);
end;
On my system anyway, the input number = returned number (key is from dbms_crypto.randombytes(32) ). For example:
select test_crypt('50610FB89D98C7D906CB0A9917413221E4FE6FA62A9604302EE2C8F63E6BAD91', 234.21) from dual;
Output:
234.21