實(shí)例講解SQL Server加密功能

更新時(shí)間：2015年07月31日 10:23:22 作者：joe321

本文實(shí)例講解了SQL Server加密功能，文章思路清晰,對(duì)SQL Server加密功能感興趣的朋友可以參考下

SQL Server中加密是層級(jí)的，每一個(gè)上層為下提供保護(hù)。如圖：

實(shí)例：
/**
SMK(Service Master Key)在SQL Server安裝時(shí)生成,由Windows DPAPI(Data Protection API)提供保護(hù)
**/

/**創(chuàng)建數(shù)據(jù)庫(kù)級(jí)別DMK(Database Master Key),受SMK保護(hù)**/
create master key encryption by password=N'Passw0rd'
go

/**數(shù)據(jù)庫(kù)內(nèi)的加密對(duì)象受DMK保護(hù)
支持的對(duì)稱加密算法:DES | TRIPLE_DES | TRIPLE_DES_3KEY | RC2 | RC4 | RC4_128| DESX | AES_128 | AES_192 | AES_256
非對(duì)稱加密算法：RSA_512 | RSA_1024 | RSA_2048
注意避免使用RC,DESX類算法,2014之后會(huì)刪除此功能
**/

--1.創(chuàng)建非對(duì)稱密鑰.

create asymmetric key asyc_key_enc 
with algorithm=RSA_1024 
encryption by password=N'Pass@word' 
go

--2.創(chuàng)建對(duì)稱密鑰.

create symmetric key symc_key_enc 
with algorithm=Triple_DES 
encryption by password=N'Pass@word' 
go

--3.創(chuàng)建證書.證書也可被其它方式保護(hù)

create certificate cert_ENC 
with subject='certificate for ENC',expiry_date='20990101' 
go

--4.對(duì)稱密鑰可由以上三種方式提供加密保護(hù)

--4.1 由非對(duì)稱密鑰加密

create symmetric key symc_key_enc_byAsyc 
with algorithm=AES_128 
encryption by asymmetric key asyc_key_enc 
go

--4.2 由對(duì)稱密鑰加密

open symmetric key symc_key_enc 
decryption by password=N'
Pass@word'; 
create symmetric key symc_key_enc_bySymc 
with algorithm = DES 
encryption by symmetric key symc_key_enc 
go

--4.3 由證書加密

create symmetric key symc_key_enc_byCert 
with algorithm =AES_128 
encryption by certificate cert_ENC 
go

/**列級(jí)數(shù)據(jù)加密和解密.MSSQL提供以下4對(duì)加密/解密函數(shù)對(duì)列數(shù)據(jù)加密
EncryptByCert() 和DecryptByCert()—利用證書對(duì)數(shù)據(jù)進(jìn)行加密和解密
EncryptByAsymKey() and DecryptByAsymKey()—利用非對(duì)稱密鑰對(duì)數(shù)據(jù)進(jìn)行加密和解密
EncryptByKey() and DecryptByKey()—利用對(duì)稱密鑰對(duì)數(shù)據(jù)進(jìn)行加密和解密
EncryptByPassphrase() and DecryptByPassphrase()—利用密碼字段產(chǎn)生對(duì)稱密鑰對(duì)數(shù)據(jù)進(jìn)行加密和解密
注意:被加密和解密的數(shù)據(jù),必需是varbinary類型
**/

--以ENCRYPTBYKEY為例，其它的大同小異

--對(duì)***號(hào)IDN進(jìn)行加密和解密

create table tb(IDN int,Name varchar(20)); 
insert into tb 
values (123456789,'BigBrother'),(090807001,'SpiderMan'),(336655789,'SuperMan') 
go

--新增列Ency_IDN存儲(chǔ)加密數(shù)據(jù),使用之前由非對(duì)稱密鑰加密的對(duì)稱密鑰symc_key_enc_byAsyc來(lái)加密數(shù)據(jù)

alter table tb add Ency_IDN varbinary(128); 
go 
open symmetric key symc_key_enc_byAsyc 
decryption by asymmetric key asyc_key_enc 
with password=N'
Pass@word'; 
update tb 
set Ency_IDN=ENCRYPTBYKEY(KEY_GUID('symc_key_enc_byAsyc'),CONVERT(Varbinary,IDN));--加密前要轉(zhuǎn)成varbinary 
close symmetric key symc_key_enc_byAsyc --顯式關(guān)閉對(duì)稱密鑰 
go

--解密被加密的列數(shù)據(jù)

open symmetric key symc_key_enc_byAsyc 
decryption by asymmetric key asyc_key_enc 
with password=N'
Pass@word'; 
select IDN,Ency_IDN,convert(int,DECRYPTBYKEY(Ency_IDN))as Decr_IDN 
from tb; 
close symmetric key symc_key_enc_byAsyc --顯式關(guān)閉對(duì)稱密鑰 
go
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