Sql Server数据库实现表中字段的列加密

use mydb;

--查看数据库中的证书
select * from sys.certificates;

--创建数据库主密钥
CREATE MASTER KEY ENCRYPTION BY PASSWORD ='123@#456';

--创建证书
CREATE CERTIFICATE MyCert
with SUBJECT = 'My Test Certificate'
GO

--创建证书并授权给指定用户(zhangsan)
CREATE CERTIFICATE MyCertToZhangSan AUTHORIZATION zhangsan 
with SUBJECT = 'My Test Certificate To ZhangSan'
GO

--创建测试表TUser_test_Cert，要对pwd字段进行加密因此其字段类型设为varbinary
--varbinary表示可变长度二进制数据，但是在sqlserver表存放是以十六进制存的。
create table TUser_test_Cert(username varchar(50),pwd varbinary(2000));

--使用MyCert证书加密pwd字段
insert into TUser_test_Cert(username,pwd) values('liming',
		ENCRYPTBYCERT(
		CERT_ID('MyCert')
		,'112233'
	)
);

select * from TUser_test_Cert;

--使用MyCert证书解密pwd字段
select username,CONVERT(
varchar(100),
DecryptByCert
	(
	CERT_ID('MyCert'),pwd
	)
) as pwd from TUser_test_Cert;

--创建一个角色zhangsan_role
create role zhangsan_role;
--给zhangsan_role这个角色分配TUser_test_Cert表的增删改查权限
grant select,update,insert,delete on TUser_test_Cert to zhangsan_role;

--使用MyCertToZhangSan证书加密pwd字段
insert into TUser_test_Cert(username,pwd) values('zhangsan',
		ENCRYPTBYCERT(
		CERT_ID('MyCertToZhangSan')
		,'666333'
	)
);

select * from TUser_test_Cert;

--使用MyCert证书解密pwd字段
select username,CONVERT(
varchar(100),
DecryptByCert
	(
	CERT_ID('MyCertToZhangSan'),pwd
	)
) as pwd from TUser_test_Cert;

----利用非对称密钥对数据进行加密和解密---

--查看数据库中的非对称密钥
select * from sys.asymmetric_keys;

--创建非对称密钥
CREATE ASYMMETRIC KEY MyTestAsymmetric
    WITH ALGORITHM = RSA_2048
    ENCRYPTION BY PASSWORD = '%^&123%456';
GO

insert into TUser_test_Cert(username,pwd) values('ssan',
		EncryptByAsymKey(
		ASYMKEY_ID('MyTestAsymmetric')
		,'112233'
		)
);

select * from TUser_test_Cert;

select username,CONVERT(
varchar(100),
DecryptByAsymKey
	(
	ASYMKEY_ID('MyTestAsymmetric'),pwd,N'%^&123%456'
	)
) as pwd from TUser_test_Cert;

----利用对称密钥对数据进行加密和解密----

--查看数据库中的对称密钥
select * from sys.symmetric_keys;

--创建对称密钥
CREATE SYMMETRIC KEY MyTestSymmetric
    WITH ALGORITHM = AES_256
    ENCRYPTION BY PASSWORD = '123456@aes';
GO
--打开密钥并进行加密/解密（只有对称加密需打开密钥！！！）
open symmetric key MyTestSymmetric decryption by password='123456@aes';

insert into TUser_test_Cert(username,pwd) values('qianqian',
		EncryptByKey(Key_GUID('MyTestSymmetric'), 'qw123sa')
);

select * from TUser_test_Cert;

select username,CONVERT(
varchar(100),
DECRYPTBYKEY(pwd) 
) as pwd from TUser_test_Cert