SSL(Secure Sockets Layer 安全套接层)，是为网络通信提供安全及数据完整性的一种安全协议，其利用公开密钥数据加密(Encryption)技术，确保数据在网络上之传输过程中不会被截取及窃听。
SSL协议提供的服务主要有：认证用户和服务器，确保数据发送到正确的客户机和服务器；
加密数据以防止数据中途被窃取； 维护数据的完整性，确保数据在传输过程中不被改变。 为了在MySQL服务器和客户端之间建立SSL联接，服务器系统必须满足：操作系统安装有OpenSSL或yaSSL；
安装的MySQL版本必须支持SSL。 本文中使用OpenSSL。 一、前提 1. 检查操作系统是否满足要求： shell>rpm -qa | grep openssl #检查是否安装OpenSSL。MySQL需要openssl的共享库。 //如果没有安装，则进行安装，官网：2. 检查数据库是否满足要求
mysql> show global variables like ‘have%ssl’; #检查是否支持ssl。NO表示不支
//持，DISABLE表示支持但未使用，如何启用见下文。
+---------------+----------+ | Variable_name | Value | +---------------+----------+ | have_openssl | DISABLED | | have_ssl | DISABLED | +---------------+----------+ 如果是使用编译好的二进制，默认都支持，如果自行编译，针对5.5版本，需要使用cmake . -DWITH_SSL=system选项。
为使客户端能够使用SSL方式进行连接，需要配置合适的证书和密钥文件，以及为用
户授予合适的权限。
二、为MySQL生成证书和密钥
1. 前提shell>mkdir -p /db/ssl
shell>cd /db/ssl
2. 创建认证机构的数字认证证书，后续服务器端和客户端的证书都使用该认证机构进行签署。
shell>openssl genrsa 2048 > ca-key.pem Generating RSA private key, 2048 bit long modulus ………+++ …………………………………………………………………………………………………..+++ e is 65537 (0×10001)shell>openssl req -new -x509 -nodes -days 3600 -key ca-key.pem -out ca-cert.pem
You are about to be asked to enter information that will be incorporated into your certificate request. What you are about to enter is what is called a Distinguished Name or a DN. There are quite a few fields but you can leave some blank For some fields there will be a default value, If you enter ‘.’, the field will be left blank. Country Name (2 letter code) [GB]:CN State or Province Name (full name) [Berkshire]:Beijing Locality Name (eg, city) [Newbury]:Beijing Organization Name (eg, company) [My Company Ltd]:CA Organizational Unit Name (eg, section) []: Common Name (eg, your name or your server’s hostname) []: Email Address []:3. 创建服务器端证书
shell>openssl req -newkey rsa:2048 -days 3600 -nodes -keyout server-key.pem \-out server-req.pem
Generating a 2048 bit RSA private key ……………….+++ …………………………+++ writing new private key to ‘server-key.pem’ You are about to be asked to enter information that will be incorporated into your certificate request. What you are about to enter is what is called a Distinguished Name or a DN. There are quite a few fields but you can leave some blank For some fields there will be a default value, If you enter ‘.’, the field will be left blank. Country Name (2 letter code) [GB]:CN State or Province Name (full name) [Berkshire]:Beijing Locality Name (eg, city) [Newbury]:Beijing Organization Name (eg, company) [My Company Ltd]:CH Organizational Unit Name (eg, section) []: Common Name (eg, your name or your server’s hostname) []:mysqlserver Email Address []:Please enter the following ‘extra’ attributes
to be sent with your certificate request A challenge password []:abc123 An optional company name []:shell>openssl rsa -in server-key.pem -out server-key.pem
//移除server-key中的passphrase[可选]
writing RSA keyshell>openssl x509 -req -in server-req.pem -days 3600 -CA ca-cert.pem -CAkey \
ca-key.pem -set_serial 01 -out server-cert.pem
//签署服务端证书
Signature ok subject=/C=CN/ST=Hangzhou/L=Hangzhou/O=CH/CN=mysqlserver Getting CA Private Key4. 创建客户端证书
shell>openssl req -newkey rsa:2048 -days 3600 -nodes -keyout \client-key.pem -out client-req.pem
Generating a 2048 bit RSA private key ………………………………………………………………………………………+++ …+++ writing new private key to ‘client-key.pem’ You are about to be asked to enter information that will be incorporated into your certificate request. What you are about to enter is what is called a Distinguished Name or a DN. There are quite a few fields but you can leave some blank For some fields there will be a default value, If you enter ‘.’, the field will be left blank. Country Name (2 letter code) [GB]:CN State or Province Name (full name) [Berkshire]:Beijing Locality Name (eg, city) [Newbury]:Beijing Organization Name (eg, company) [My Company Ltd]:CH Organizational Unit Name (eg, section) []: Common Name (eg, your name or your server’s hostname) []:mysqlclient Email Address []:Please enter the following ‘extra’ attributes
to be sent with your certificate request A challenge password []:abc123 An optional company name []:shell>openssl rsa -in client-key.pem -out client-key.pem
//移除client-key中的passphrase[可选]
writing RSA keyshell>openssl x509 -req -in client-req.pem -days 3600 -CA ca-cert.pem \
-CAkey ca-key.pem -set_serial 01 -out client-cert.pem
//签署客户端证书
Signature ok subject=/C=CN/ST=Hangzhou/L=Hangzhou/O=CH/CN=mysqlclient Getting CA Private Key5. 生成完毕后，验证步骤如下
shell>openssl verify -CAfile ca-cert.pem server-cert.pem client-cert.pem server-cert.pem: OK client-cert.pem: OK6. 综上步骤，生成如下文件：
ca-cert.pem 在服务器端和客户端都是用 ssl-ca=ca-cert.pem
server-cert.pem,server-key.pem 服务器端指定 ssl-cert=server-cert.pem 和 \ssl-key=server-key.pem
client-cert.pem,client-key.pem 客户端指定 ssl-cert=client-cert.pem 和 \
ssl-key=client-key.pem
三、配置SSL连接 实现使用SSL进行配置和赋权的两种方案 1. 方案1 Server: 1）在服务器端的配置文件my.cnf中添加如下参数： [mysqld] ssl-cert=/db/ssl/server-cert.pem ssl-key=/db/ssl/server-key.pem 2）重启mysqld。用户赋权，用GRANT语句的REQUIRE SSL选项
mysql>create user identified by ‘abc’; mysql>grant select on testdb.* to require ssl;
Client:
mysql -u user -pabc -P 3300 ssl-ca=ca-cert.pem2. 方案2
Server: 1）在服务器端的配置文件my.cnf中添加如下参数： [mysqld] ssl-ca=/db/ssl/ca-cert.pem ssl-cert=/db/ssl/server-cert.pem ssl-key=/db/ssl/server-key.pem 2）重启mysqld。用户赋权，用GRANT语句的REQUIRE x509选项
mysql>create user identified by ‘abc’; mysql>grant select on testdb.* to require x509;Client:
mysql -u user -pabc -P 3300 ssl-ca=ca-cert.pem ssl-key=client-key.pem \ssl-cert=client-cert.pem
注意：方案2的验证要求更严格，需要指定key和cert，因此推荐使用方案2。
四、检查
1. 配置完成后，可以如下方式查看自身对ssl的支持： mysql> show global variables like ‘%ssl%’; #查看服务器是否支持SSL连接+---------------+-------------------------+
| Variable_name | Value | +---------------+-------------------------+ | have_openssl | YES | | have_ssl | YES | | ssl_ca | /db/ssl/ca-cert.pem | | ssl_capath | | | ssl_cert | /db/ssl/server-cert.pem | | ssl_cipher | | | ssl_key | /db/ssl/server-key.pem | +---------------+-------------------------+ mysql> SHOW STATUS LIKE ‘Ssl_cipher’; #查看本连接是否是SSL加密的连接 +---------------+--------------------+ | Variable_name | Value | +---------------+--------------------+ | Ssl_cipher | DHE-RSA-AES256-SHA | +---------------+--------------------+1. 通过抓包工具，相同的select * from t1命令，可以明显看到加密前后包信息的不同。
1)加密前： 
2)加密后：
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附：SSL协议的工作方式简介
客户端要收发几个握手信号：发送一个“ClientHello”消息，说明它支持的密码算法列表、压缩方法及最高协议版本，也发送稍后将被使用的随机数。
然后收到一个“ServerHello”消息，包含服务器选择的连接参数，源自客户端初期所提供的“ClientHello”。当双方知道了连接参数，客户端与服务器交换证书（依靠被选择的公钥系统）。这些证书通常基于X.509，不过已有草案支持以OpenPGP为基础的证书。 服务器请求客户端公钥。客户端有证书即双向身份认证，没证书时随机生成公钥。客户端与服务器通过公钥保密协商共同的主私钥（双方随机协商），这通过精心谨慎设计的伪随机数功能实现。结果可能使用Diffie-Hellman交换，或简化的公钥加密，双方各自用私钥解密。所有其他关键数据的加密均使用这个“主密钥”。引自：