การเข้ารหัสข้อมูลด้วย ORACLE DBMS_CRYPTO

CREATE OR REPLACE PACKAGE EN_DE
AS
FUNCTION ENCRYPT (p_plainText VARCHAR2) RETURN RAW DETERMINISTIC;
FUNCTION DECRYPT (p_encryptedText RAW) RETURN VARCHAR2 DETERMINISTIC;
END;
/


CREATE OR REPLACE PACKAGE BODY "EN_DE"
AS
encryption_type PLS_INTEGER := DBMS_CRYPTO.ENCRYPT_DES
+ DBMS_CRYPTO.CHAIN_CBC
+ DBMS_CRYPTO.PAD_PKCS5;
   /*
   ENCRYPT_DES is the encryption algorithem. Data Encryption Standard. Block cipher. Uses key length of 56 bits.
   CHAIN_CBC Cipher Block Chaining. Plaintext is XORed with the previous ciphertext block before it is encrypted.
   PAD_PKCS5 Provides padding which complies with the PKCS #5: Password-Based Cryptography Standard
   */
   encryption_key RAW (32) := UTL_RAW.cast_to_raw('OneTwoThree');
-- The encryption key for DES algorithem, should be 8 bytes or more. 

FUNCTION ENCRYPT (p_plainText VARCHAR2) RETURN RAW DETERMINISTIC
 IS
    encrypted_raw      RAW (32767);
 BEGIN
    encrypted_raw := DBMS_CRYPTO.ENCRYPT
    (
       src => UTL_RAW.CAST_TO_RAW (p_plainText),
       typ => encryption_type,
       KEY => encryption_key
    );
   RETURN encrypted_raw;
 END ENCRYPT;

 FUNCTION DECRYPT (p_encryptedText RAW) RETURN VARCHAR2 DETERMINISTIC
 IS
    decrypted_raw      RAW (32767);
 BEGIN
    decrypted_raw := DBMS_CRYPTO.DECRYPT
    (
        src => p_encryptedText,
        typ => encryption_type,
        KEY => encryption_key
    );
    RETURN (UTL_RAW.CAST_TO_VARCHAR2 (decrypted_raw));
 END DECRYPT;