1.查看是否安裝httpd和SSL（如果有就可以進行下一步）

[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.生成服務器私鑰（以abc.cn為例）

[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.用私鑰server.key文件生成證書請求文件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 #國家
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 #公司名稱/個人直接填寫姓名
Organizational Unit Name (eg, section) []:22 #部門名稱/個人直接填寫姓名
Common Name (eg, your name or your server's hostname) []:abc.cn #需要申請的域名
Email Address []:22@22.cn
Please enter the following 'extra' attributes
to be sent with your certificate request #提示你輸入一個密碼,不用理他直接回車
A challenge password []:
An optional company name []:
[root@local opt]#