Openssl生成证书流程
偶然想到在内网配置https，就梳理了下利用openssl与ca生成证书的过程。
生成过程分为服务端跟客户端，这里我在一台上测试。
一.介绍
CA是Certificate Authority的缩写，也就是认证中心。
CA的功能有：颁发证书，更新证书，撤销证书和验证证书，相当于公安局的户籍部门。
CA证书的作用是作身份认证。
数字证书认证过程：
×××办理过程： 带上户口本-》当地派出所-》签发证书-》你去领证书
×××办理过程： 带上户口本（证明你合法）-》当地派出所（认证机构）-》签发证书（审核有效信息）-》你去领证书。
客户得到CA证书的流程如下：

CSR文件根据客户端的公钥和主机标识生成，主机标识包括国家，省区，县市，组织，邮箱，主机名等信息。用户在拿到数字证书后，用浏览器中的CA的公钥解开证书，得到客户端的标识，从而确认身份

二.搭建
1.必备软件openssl，查看是否已安装
[root@ayu conf]# rpm -qf which openssl
openssl-1.0.1e-48.el6_8.3.x86_64
2.配置自己的CA认证中心。生成CA的根证书和私钥，根证书包括CA的公钥
修改openssl配置文件[root@ayu conf]# vim /etc/pki/tls/openssl.cnf
修改如下
#basicConstraints=CA:FALSE
basicConstraints=CA:TRUE设置使用本地为CA认证中心。
[root@ayu conf]# /etc/pki/tls/misc/CA -h
usage: /etc/pki/tls/misc/CA -newcert|-newreq|-newreq-nodes|-newca|-sign|-verify
选项 ：
-newcert 新证书
-newreq 新请求
-newreq-nodes 新请求节点
-newca 新的CA证书
-sign 签证
-verify 验证
[root@ayu conf]# /etc/pki/tls/misc/CA -newcert
Generating a 2048 bit RSA private key
.+++
...........................................................................................................................+++
writing new private key to 'newkey.pem'
Enter PEM pass phrase:输入保护秘钥文件的密码
Verifying - Enter PEM pass phrase:

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) [XX]:CH
State or Province Name (full name) []:hubei
Locality Name (eg, city) [Default City]:wuhan
Organization Name (eg, company) [Default Company Ltd]:ayu
Organizational Unit Name (eg, section) []:ayu
Common Name (eg, your name or your server's hostname) []:ayu
Email Address []:123@qq.com
Certificate is in newcert.pem, private key is in newkey.pem
[root@ayu certificate]# ll
总用量 8
-rw-r--r--. 1 root root 1350 3月 20 00:50 newcert.pem
-rw-r--r--. 1 root root 1834 3月 20 00:50 newkey.pem
可以看到已经生成两个文件，一个为根证书（公钥），一个为秘钥。
3.客户端认证文件准备
[root@ayu certificate_keys]# openssl genrsa -des3 -out server.key
Generating RSA private key, 1024 bit long modulus
.............++++++
................++++++
e is 65537 (0x10001)
Enter pass phrase for server.key:输入私钥密码
Verifying - Enter pass phrase for server.key:
生成客户端私钥秘钥文件，des3是保护私钥的密码的加密算法
生成客户端的认证请求文件
[root@ayu certificate_keys]# openssl req -new -key server.key -out server.csr
Enter pass phrase for server.key:
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) [XX]:CH 这些信息与CA的主机标识相同，否则认证会出错
State or Province Name (full name) []:hubei
Locality Name (eg, city) [Default City]:wuhan
Organization Name (eg, company) [Default Company Ltd]:ayu
Organizational Unit Name (eg, section) []:ayu
Common Name (eg, your name or your server's hostname) []:ayu
Email Address []:123@163.com

Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:不输入密码
An optional company name []:不输入密码
[root@ayu certificate_keys]# ll
总用量 8
-rw-r--r--. 1 root root 668 3月 20 01:23 server.csr
-rw-r--r--. 1 root root 963 3月 20 01:18 server.key
生成的csr文件即根据私钥文件生成的包含公钥的请求文件
4.CA认证请求证书
[root@ayu certificate_keys]# openssl ca -keyfile /root/certificate/newkey.pem -cert /root/certificate/newcert.pem -in server.csr -out server.crt
Using configuration from /etc/pki/tls/openssl.cnf
Enter pass phrase for /root/certificate/newkey.pem:
/etc/pki/CA/index.txt: No such file or directory
unable to open '/etc/pki/CA/index.txt'
140602402772808:error:02001002:system library:fopen:No such file or directory:bss_file.c:398:fopen('/etc/pki/CA/index.txt','r')
140602402772808:error:20074002:BIO routines:FILE_CTRL:system lib:bss_file.c:400:
出现报错
此时需要做以下操作
[root@ayu certificate_keys]# touch /etc/pki/CA/index.txt
[root@ayu certificate_keys]# echo 01 > /etc/pki/CA/serial
[root@ayu certificate_keys]# openssl ca -keyfile /root/certificate/newkey.pem -cert /root/certificate/newcert.pem -in server.csr -out server.crt
Using configuration from /etc/pki/tls/openssl.cnf
Enter pass phrase for /root/certificate/newkey.pem:
Check that the request matches the signature
Signature ok
Certificate Details:
Serial Number: 1 (0x1)
Validity
Not Before: Mar 20 05:37:46 2018 GMT
Not After : Mar 20 05:37:46 2019 GMT
Subject:
countryName = CH
stateOrProvinceName = hubei
organizationName = ayu
organizationalUnitName = ayu
commonName = ayu
emailAddress = 123@163.com
X509v3 extensions:
X509v3 Basic Constraints:
CA:FALSE
Netscape Comment:
OpenSSL Generated Certificate
X509v3 Subject Key Identifier:
00:4C:C6:86:B4:EF:88:51:FC:DB:59:C7:D8:32:20:08:81:7A:4B:D8
X509v3 Authority Key Identifier:
keyid:8A:41:B4:0B:50:11:DC:27:24:A8:29:E6:3B:5A:D1:AB:66:29:3A:EC

Certificate is to be certified until Mar 20 05:37:46 2019 GMT (365 days)
Sign the certificate? [y/n]:y

1 out of 1 certificate requests certified, commit? [y/n]y
Write out database with 1 new entries
Data Base Updated
[root@ayu certificate_keys]# ll
总用量 12
-rw-r--r--. 1 root root 3747 3月 20 01:37 server.crt
-rw-r--r--. 1 root root 668 3月 20 01:23 server.csr
-rw-r--r--. 1 root root 963 3月 20 01:18 server.key
创建成功。
测试https配置是否成功
在nginx配置问价加上以下字段
listen 443 ssl;
ssl_certificate /usr/local/nginx/conf/certificate_keys/server.crt;
ssl_certificate_key /usr/local/nginx/conf/certificate_keys/server.key;

重启nginx，测试访问：