How to encrypt/decrypt strings with the dbms_obfuscation_toolkit package

13.10.2005

How to encrypt/decrypt strings with the dbms_obfuscation_toolkit / dbms_crypto packages

Oracle 9i dbms_obfuscation_toolkit package

CREATE OR REPLACE PACKAGE Cryptit AS
FUNCTION encrypt( Str VARCHAR2 ) RETURN RAW;
FUNCTION decrypt( xCrypt VARCHAR2 ) RETURN VARCHAR2;
END Cryptit;
/

CREATE OR REPLACE PACKAGE BODY Cryptit AS
crypt_raw RAW(2000);
crypt_str VARCHAR(2000);

-- Encrypt the string --
FUNCTION encrypt( Str VARCHAR2 ) RETURN RAW AS

   l INTEGER := LENGTH(str);
   i INTEGER;
   padblock RAW(2000);
   Cle RAW(8) := UTL_RAW.CAST_TO_RAW('frankzap');

   BEGIN
      i := 8-MOD(l,8);
      padblock := utl_raw.cast_to_raw(str||RPAD(CHR(i),i,CHR(i)));

      dbms_obfuscation_toolkit.DESEncrypt(
               input     => padblock,
               KEY       => Cle,
               encrypted_data => crypt_raw );
      RETURN crypt_raw ;
   END;

   -- Decrypt the string --
   FUNCTION decrypt( xCrypt VARCHAR2 ) RETURN VARCHAR2 AS
   l NUMBER;
   Cle RAW(8) := UTL_RAW.CAST_TO_RAW('frankzap');
   crypt_raw RAW(2000) := utl_raw.cast_to_raw(utl_raw.cast_to_varchar2(xCrypt)) ;
   BEGIN
      dbms_obfuscation_toolkit.DESDecrypt(
               input     => xCrypt,
               KEY       => Cle,
               decrypted_data => crypt_raw );
      crypt_str := utl_raw.cast_to_varchar2(crypt_raw);
      l := LENGTH(crypt_str);
      crypt_str := RPAD(crypt_str,l-ASCII(SUBSTR(crypt_str,l)));
      RETURN crypt_str;
   END;
END Cryptit;
/

SQL*Plus: Release 9.0.1.3.0 - Production on Je Oct 13 10:28:55 2005

Connecté à :
Oracle9i Enterprise Edition Release 9.2.0.5.0 - 64bit Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.5.0 - Production

SQL> set serveroutput on
SQL>
SQL> DECLARE
2    LC$Code VARCHAR2(100) := 'Music is the best!' ;
3 BEGIN
4
5    -- Get the encrypted string --
6    LC$Code := Cryptit.Encrypt( LC$Code ) ;
7    dbms_output.put_line( LC$Code ) ;
8
9    -- Get the decrypted string --
10    LC$Code := Cryptit.Decrypt( LC$Code ) ;
11    dbms_output.put_line( LC$Code ) ;
12
13 END ;
14
15 /
7840712517939382157F5BA660E3AAB094E9C2BA67FF4234
Music is the best!

Procédure PL/SQL terminée avec succès.

SQL>

Oracle 10g dbms_crypto package

SQL> set serveroutput on
SQL>
SQL> DECLARE
2   LC$Source    VARCHAR2(19) := 'Music is the best!';
3   LR$Source    RAW(128) := utl_raw.cast_to_raw(LC$Source);
4   LR$Key       RAW(128) := utl_raw.cast_to_raw('FrankZappa');
5   LR$Crypted   RAW(2048);
6   LR$Decrypted RAW(2048);
7
8 BEGIN
9
10    dbms_output.put_line('Source string : ' || LC$Source);
11
12    LR$Crypted := dbms_crypto.encrypt(LR$Source,
13    dbms_crypto.des_cbc_pkcs5, LR$Key);
14
15    dbms_output.put_line('Encrypted raw : ' ||
16    RAWTOHEX(utl_raw.cast_to_raw(LR$Crypted)));
17
18    LR$Decrypted := dbms_crypto.decrypt(src => LR$Crypted,
19    typ => dbms_crypto.des_cbc_pkcs5, key => LR$Key);
20
21    dbms_output.put_line('Decrypted string : ' ||
22    utl_raw.cast_to_varchar2(LR$Decrypted));
23 END;
24 /
Source string : Music is the best!
Encrypted raw :
33454635363638343931453734313342373337454141313133453637323639373934373433463442
4533464246333831
Decrypted string : Music is the best!

PL/SQL procedure successfully completed.

SQL>

Francois