1.查看是否安装httpd和SSL（如果有就可以进行下一步）

[root@localhost ~]# rpm -qa | grep httpd

httpd-tools-2.2.15-47.el6.centos.4.x86_64

[root@localhost ~]# rpm -qa | grep ssl

openssl-1.0.1e-42.el6_7.4.x86_64

openssl-devel-1.0.1e-42.el6_7.4.x86_64

docbook-style-dsssl-1.79-10.el6.noarch

mod_ssl-2.2.15-47.el6.centos.4.x86_64

nss_compat_ossl-0.9.6-1.el6.x86_64

2.生成服务器私钥（以abc.cn为例）

[root@localhost /]# cd /opt

[root@local opt]# openssl genrsa -out abc.cn.key 2048

Generating RSA private key, 2048 bit long modulus

...............+++

...............+++

e is 65537 (0x10001)

3.用私钥server.key文件生成证书请求文件csr

[root@local opt]# openssl req -new -out abc.cn.csr -sha256 -key abc.cn.key

You are about to be asked to enter information that will be incorporated

into your certificate request.

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) [XX]:CN #国家

State or Province Name (full name) []:zhejiang #省份

Locality Name (eg, city) [Default City]:hangzhou #城市

Organization Name (eg, company) [Default Company Ltd]:22 #公司名称/个人直接填写姓名

Organizational Unit Name (eg, section) []:22 #部门名称/个人直接填写姓名

Common Name (eg, your name or your server's hostname) []:abc.cn #需要申请的域名

Email Address []:22@22.cn

Please enter the following 'extra' attributes

to be sent with your certificate request #提示你输入一个密码,不用理他直接回车

A challenge password []:

An optional company name []:

[root@local opt]#