oracle从8i开始提供一个数据加密包:dbms_obfuscation_toolkit.利用这个包,我们可以对数据进行DES,Triple DES或者MD5加密. 本文就此讲解如何使用以及使用过程需要注意的问题.1. dbms_obfuscation_toolkit简介dbms_obfuscation_toolkit主要有一下几个存储过程:-DESGETKEY   -- 产生密钥,用于DES算法DES3GETKEY  -- 产生密钥,用于Triple DES算法DESENCRYPT  -- 用DES算法加密数据DESDECRYPT  -- 用DES算法解密数据DES3ENCRYPT -- 用Triple DES算法加密数据DES3DECRYPT -- 用DES算法解密数据MD5         -- 用MD5算法加密数据2. 准备数据表在开始前，我们先创建表users:drop table users;

create table users(

userid varchar2(50) primary key,

password varchar2(64),  --密码原文

encrypted varchar2(64)  --加密后的密码

);insert into users values ('user1','user1234',null);

insert into users values ('user2','abcd1234',null);

insert into users values ('user3','oracle12',null);

commit;3. 创建包PG_ENCRYPT_DECRYPTcreate  or replace package PG_ENCRYPT_DECRYPT is

iKey varchar2(8):='oracle9i';

function GEN_RAW_KEY  ( iKey in varchar2) return raw;

function DECRYPT_3KEY_MODE(iValue in raw,iMode in pls_integer)return varchar2;

function ENCRYPT_3KEY_MODE(iValue in varchar2,iMode in pls_integer)return raw;

end;

/

create or replace package body PG_ENCRYPT_DECRYPT is

function GEN_RAW_KEY  ( iKey in varchar2)

return raw

as

rawkey raw(240) := '';

begin

for i in 1..length(iKey) loop

rawkey := rawkey||hextoraw(to_char(ascii(substr(iKey, i, 1))));

end loop;

return rawkey;

end;

/*

Creating function DECRYPT_3KEY_MODE

*/

FUNCTION DECRYPT_3KEY_MODE  (

iValue in raw, iMode in pls_integer

)

return varchar2

as

vDecrypted varchar2(4000);

rawkey raw(240) := '';

begin

rawkey := GEN_RAW_KEY(iKey);

-- decrypt input string

vDecrypted := dbms_obfuscation_toolkit.des3decrypt (

UTL_RAW.CAST_TO_VARCHAR2(iValue)

, key_string => rawkey

, which => iMode

);

return vDecrypted;

end;

/*

Creating function ENCRYPT_3KEY_MODE

*/

FUNCTION ENCRYPT_3KEY_MODE  (

iValue in varchar2,  iMode in pls_integer

)

return raw

as

vEncrypted varchar2(4000);

vEncryptedRaw Raw(2048);

rawkey raw(240) := '';

begin

rawkey := GEN_RAW_KEY(iKey);

-- encrypt input string

vEncrypted := dbms_obfuscation_toolkit.des3encrypt (

iValue

, key_string => rawkey

, which => iMode

);

-- convert to raw as out

vEncryptedRaw := UTL_RAW.CAST_TO_RAW(vEncrypted);

return vEncryptedRaw;

end;

end;4. 测试在SQL Plus下输入:SQL > update users set encrypted = PG_ENCRYPT_DECRYPT.ENCRYPT_3KEY_MODE(password,1);

SQL > commit;执行完以上SQL语句后,encrypted 存储的就是加密后的password字段.我们看一下结果:-SQL > select * from users;

USERID PASSWORD  ENCRYPTED

------ --------- ----------------

user1  user1234  69EF3A211A0F2C32

user2  abcd1234  CF7562203F6CEDE5

user3  oracle12  65D71D7148FA001D这个加密结果是否正确? 我们对加密结果解密就知道了,在SQL Plus下输入:SQL > select userid,password,PG_ENCRYPT_DECRYPT.DECRYPT_3KEY_MODE(encrypted,1) DECRYPTED from users;

USERID PASSWORD  DECRYPTED

------ --------- ----------

user1  user1234  user1234

user2  abcd1234  abcd1234

user3  oracle12  oracle12大家可以看到,解密结果和密码原文完全一模一样.这说明我们的加密解密过程是正确的.5. 进一步思考我们再看一下表users:-create table users(

userid varchar2(50) primary key,

password varchar2(64),  --密码原文

encrypted varchar2(64)  --加密后的密码

);还有我们插入的数据:-insert into users values ('user1','user1234',null);

insert into users values ('user2','abcd1234',null);

insert into users values ('user3','oracle12',null);以及加密输出结果:-[/code]USERID PASSWORD  ENCRYPTED------ --------- ----------------user1  user1234  69EF3A211A0F2C32user2  abcd1234  CF7562203F6CEDE5user3  oracle12  65D71D7148FA001D[/code]不知细心的朋友注意到没有? 在表中,password 和 encrypted 的长度都是64,都是8的倍数, 再看一下我们的密码原文和加密后的密码也是8的倍数,这不是巧合,而是DES算法和Triple DES算法的特征之一. 输入长度必须是8的倍数,而输出也是8的倍数,所以我们的字段长度也是8的倍数. 如果输入不是8的倍数会怎样? 大家可以把密码原文修改一下试试.6. 密钥的保存不管我们用什么样的加密算法,有一点非常重要的是:  密钥的保存.密钥就是一把钥匙,因为加密算法是公开的,所以你无论如何加密,只要我知道你的密钥,我就可以解密,那么你的加密就没有效果.在本文中, 我们的密钥是这样定义的:-iKey varchar2(8):='oracle9i';oracle9i就是我们的密钥.所以,如果只是简单地把以上程序在oracle上运行一下就使用,那么任何有权限登陆的人看到这个程序,就可以知道密钥. 所以简单的做法是利用Oracle提供的WRAP把整个程序加密,用加密后的文本创建程序. 这样别人就看不到你的源代码了.把程序保存为source.sql,在Dos命令下输入:-Wrap iname=source.sql oname=target.sql

就可以了,然后SQL Plus运行target.sql.

当然了, 这里讲的密钥保存还是很简单的. 并不是百分百保险. 大家可以自己

想想如何更安全地保持你的密钥.

oracle 10g 加密包改为：DBMS_CRYPTOGeneral Information

Source{ORACLE_HOME}/rdbms/admin/dbmsobtk.sql

Algorithm ConstantsNameData TypeValue

Hash Functions

HASH_MD4 (128 bit hash)PLS_INTEGER1

HASH_MD5 (128 bit hash)PLS_INTEGER2

HASH_SH1 (160 bit hash)PLS_INTEGER3

MAC Functions

HMAC_MD5 (128 bit hash)PLS_INTEGER1

HMAC_SH1 (160 bit hash)PLS_INTEGER2

Block Cipher Algorithms

ENCRYPT_DES (56 bit)PLS_INTEGER1; -- 0x0001

ENCRYPT_3DES_2KEY (128 bit)PLS_INTEGER2; -- 0x0002

ENCRYPT_3DESPLS_INTEGER3; -- 0x0003

ENCRYPT_AES128 (128 bit)PLS_INTEGER6; -- 0x0006

ENCRYPT_AES192 (192 bit)PLS_INTEGER7; -- 0x0007

ENCRYPT_AES256 (256 bit)PLS_INTEGER8; -- 0x0008

ENCRYPT_RC4 (Stream Cipher)PLS_INTEGER129; -- 0x0081

Block Cipher Chaining Modifiers

CHAIN_CBC (Cipher Block Chaining)PLS_INTEGER256; -- 0x0100

CHAIN_CFB (Cipher Feedback)PLS_INTEGER512; -- 0x0200

CHAIN_ECB (Electronic cookbook)PLS_INTEGER768; -- 0x0300

CHAIN_OFB (Output Feedback)PLS_INTEGER1024; -- 0x0400

Block Cipher Padding Modifiers

PAD_PKCS5 (Complies with PKCS #5)PLS_INTEGER4096; -- 0x1000

PAD_NONE (No Dadding)PLS_INTEGER8192; -- 0x2000

PAD_ZERO (Pad with Zeros)PLS_INTEGER12288; -- 0x3000

Block Ciphers Suites

DES_CBC_PKCS5PLS_INTEGERENCRYPT_DES

+ CHAIN_CBC

+ PAD_PKCS5;

DES3_CBC_PKCS5PLS_INTEGERENCRYPT_3DES

+ CHAIN_CBC

+ PAD_PKCS5;

DependenciesDBMS_CRYPTO_FFIDECRYPTBYTESENCRYPTBYTES

DECRYPTENCRYPTUTL_RAW

ExceptionsError CodeReason

28827The specified cipher suite is not defined

28829No value has been specified for the cipher suite to be used

28233Source data was previously encrypted

28234DES: Specified key size too short. DES keys must be at least 8 bytes (64 bits).

AES: Specified key size is not supported. AES keys must be 128, 192, or 256 bits

28239The encryption key has not been specified or contains a NULL value

DECRYPT

Decrypt crypt text data using stream or block cipher with user supplied key and optional iv

Overload 1dbms_crypto.decrypt(src IN RAW, typ IN PLS_INTEGER, key IN RAW,

iv  IN RAW DEFAULT NULL) RETURN RAW;

See Encrypt Overload 1 demo

Overload 2dbms_crypto.decrypt(dst IN OUT NOCOPY BLOB, src IN BLOB,

typ IN PLS_INTEGER, key IN RAW, iv  IN RAW DEFAULT NULL);

Overload 3dbms_crypto.decrypt (dst IN OUT NOCOPY CLOB CHARACTER SET ANY_CS,

src IN BLOB, typ IN PLS_INTEGER, key IN RAW,

iv  IN RAW DEFAULT NULL);

ENCRYPT

Encrypt plain text data using stream or block cipher with user supplied key and optional iv

Overload 1dbms_crypto.encrypt(src IN RAW, typ IN PLS_INTEGER, key IN RAW,

iv IN RAW DEFAULT NULL) RETURN RAW;

set serveroutput on

DECLARE

l_credit_card_no VARCHAR2(19) := '1234-5678-9012-3456';

l_ccn_raw RAW(128) := utl_raw.cast_to_raw(l_credit_card_no);

l_key     RAW(128) := utl_raw.cast_to_raw('abcdefgh');

l_encrypted_raw RAW(2048);

l_decrypted_raw RAW(2048);

BEGIN

dbms_output.put_line('Original : ' || l_credit_card_no);

l_encrypted_raw := dbms_crypto.encrypt(l_ccn_raw,

dbms_crypto.des_cbc_pkcs5, l_key);

dbms_output.put_line('Encrypted : ' ||

RAWTOHEX(utl_raw.cast_to_raw(l_encrypted_raw)));

l_decrypted_raw := dbms_crypto.decrypt(src => l_encrypted_raw,

typ => dbms_crypto.des_cbc_pkcs5, key => l_key);

dbms_output.put_line('Decrypted : ' ||

utl_raw.cast_to_varchar2(l_decrypted_raw));

END;

/

set serveroutput on

DECLARE

enc_val   RAW(2000);

l_key     RAW(2000);

l_key_len NUMBER := 128/8; -- convert bits to bytes

l_mod     NUMBER := dbms_crypto.ENCRYPT_AES128

+ dbms_crypto.CHAIN_CBC+ dbms_crypto.PAD_PKCS5;

BEGIN

l_key := dbms_crypto.randombytes(l_key_len);

enc_val := dbms_crypto.encrypt(

utl_i18n.string_to_raw('1234-5678-9012-3456', 'AL32UTF8'),

l_mod, l_key);

dbms_output.put_line(enc_val);

END;

/

Overload 2dbms_crypto.encrypt(dst IN OUT NOCOPY BLOB, src IN BLOB,

typ IN PLS_INTEGER, key IN RAW, iv  IN RAW DEFAULT NULL);

Overload 3dbms_crypto.encrypt(dst IN OUT NOCOPY BLOB,

src IN CLOB CHARACTER SET ANY_CS, typ IN PLS_INTEGER, key IN RAW, iv  IN RAW DEFAULT NULL);

dbms_crypto.encrypt(UTL_RAW.CAST_TO_RAW(CONVERT('XXX','AL32UTF8')),typ,key);

HASH

Hash source data by cryptographic hash type

Overload 1dbms_crypto.hash(src IN RAW, typ IN PLS_INTEGER) RETURN RAW;

Overload 2dbms_crypto.hash(src IN BLOB, typ IN PLS_INTEGER) RETURN RAW;

Overload 3dbms_crypto.hash(src IN CLOB CHARACTER SET ANY_CS,

typ IN PLS_INTEGER) RETURN RAW;

MAC

Message Authentication Code algorithms provide keyed message protection

Overload 1dbms_crypto.mac(src IN RAW, typ IN PLS_INTEGER, key IN RAW)

RETURN RAW;

Overload 2dbms_crypto.mac(src IN BLOB, typ IN PLS_INTEGER, key IN RAW)

RETURN RAW;

Overload 3dbms_crypto.mac(src IN CLOB CHARACTER SET ANY_CS,

typ IN PLS_INTEGER, key IN RAW) RETURN RAW;

RANDOMBYTES

Returns a raw value containing a pseudo-random sequence of bytesdbms_crypto.randomnytes(number_bytes PLS_INTEGER) RETURN RAW;

SELECT dbms_crypto.randombytes(1) FROM dual;

SELECT LENGTH(dbms_crypto.randombytes(1)) FROM dual;

SELECT dbms_crypto.randombytes(28) FROM dual;

SELECT LENGTH(dbms_crypto.randombytes(28)) FROM dual;

SELECT dbms_crypto.randombytes(64) FROM dual;

SELECT LENGTH(dbms_crypto.randombytes(64)) FROM dual;

RANDOMINTEGER

Returns a random BINARY_INTEGERdbms_crypto.randominteger RETURN NUMBER;

SELECT dbms_crypto.randominteger FROM dual;

RANDOMNUMBER

Returns a random Oracle Numberdbms_crypto.randomnumber RETURN NUMBER;

SELECT dbms_crypto.randomnumber FROM dual;