摘要：官網(wǎng)安裝安裝非常簡單直接克隆就可以了生成通配符證書期間需要根據(jù)提示設(shè)置記錄用作你對判斷你是否擁有域名使用權(quán)其中換成你的一級域名即可參數(shù)說明表示安裝模式，有安裝模式和驗(yàn)證模式兩種類型的插件。

官網(wǎng)：https://letsencrypt.org/

安裝非常簡單直接克隆就可以了

git clone https://github.com/letsencrypt/letsencrypt

期間需要根據(jù)提示設(shè)置DNS TXT記錄,用作你對判斷你是否擁有域名使用權(quán)

 cd letsencrypt
./certbot-auto certonly  -d *.you.cn --manual --preferred-challenges dns --server https://acme-v02.api.letsencrypt.org/directory

其中"you.cn"換成你的一級域名即可

Dependency Installed:
  dwz.x86_64 0:0.11-3.el7             perl-srpm-macros.noarch 0:1-8.el7             tcl.x86_64 1:8.5.13-8.el7             tix.x86_64 1:8.4.3-12.el7             tk.x86_64 1:8.5.13-6.el7             tkinter.x86_64 0:2.7.5-69.el7_5            

Complete!
Creating virtual environment...
Installing Python packages...
Installation succeeded.
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator manual, Installer None
Enter email address (used for urgent renewal and security notices) (Enter "c" to
cancel): [email protected]

接下來需要輸入些指令

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Please read the Terms of Service at
https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf. You must
agree in order to register with the ACME server at
https://acme-v02.api.letsencrypt.org/directory
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
(A)gree/(C)ancel: A
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Would you be willing to share your email address with the Electronic Frontier
Foundation, a founding partner of the Let"s Encrypt project and the non-profit
organization that develops Certbot? We"d like to send you email about our work
encrypting the web, EFF news, campaigns, and ways to support digital freedom.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
(Y)es/(N)o: N
Obtaining a new certificate
Performing the following challenges:
dns-01 challenge for kuaichuangkeji.com

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
NOTE: The IP of this machine will be publicly logged as having requested this
certificate. If you"re running certbot in manual mode on a machine that is not
your server, please ensure you"re okay with that.

Are you OK with your IP being logged?
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
(Y)es/(N)o: Y

這里有幾個需交互的提示

是否同意 Let"s Encrypt 協(xié)議要求=>需要同意

是否分享你的郵箱

詢問是否對域名和機(jī)器（IP）進(jìn)行綁定=>需要同意

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Please deploy a DNS TXT record under the name
_acme-challenge.you.cn with the following value:

RYtObhDvEcXewZckknNQkBKIkvwIlbb4PNRel74LNwU

Before continuing, verify the record is deployed.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Press Enter to Continue
Waiting for verification...
Cleaning up challenges

要求配置 DNS TXT 記錄，從而校驗(yàn)域名所有權(quán)，也就是判斷證書申請者是否有域名的所有權(quán)。

上面輸出要求給 _acme-challenge.you.cn 配置一條 TXT 記錄，在沒有確認(rèn) TXT 記錄生效之前不要回車執(zhí)行。

我用的是阿里云的域名服務(wù)器，控制臺具體操作如下圖所示：

確認(rèn)生效后，回車執(zhí)行，輸出如下

IMPORTANT NOTES:
 - Congratulations! Your certificate and chain have been saved at:
   /etc/letsencrypt/live/you.cn/fullchain.pem
   Your key file has been saved at:
   /etc/letsencrypt/live/you.cn/privkey.pem
   Your cert will expire on 2019-02-27. To obtain a new or tweaked
   version of this certificate in the future, simply run certbot-auto
   again. To non-interactively renew *all* of your certificates, run
   "certbot-auto renew"
 - If you like Certbot, please consider supporting our work by:

   Donating to ISRG / Let"s Encrypt:   https://letsencrypt.org/donate
   Donating to EFF:                    https://eff.org/donate-le

看到這個界面內(nèi)容的話，恭喜你，證書安裝成功了。

注:證書在到期前30天才會續(xù)簽成功,但為了確保證書在運(yùn)行過程中不過期,官方建議每天自動執(zhí)行續(xù)簽兩次;
使用crontab自動續(xù)期

crontab -e // 編輯定時任務(wù)
0 */12 * * * certbot renew --quiet --renew-hook "/etc/init.d/nginx reload"

需要注意"/etc/init.d/nginx reload"為nginx重啟命令，需要根據(jù)自己服務(wù)器的重啟命令重啟即可；這里建議使用reload，不推薦使用restart，因?yàn)檫@樣萬一配錯了，也不會影響服務(wù)器其他項(xiàng)目的運(yùn)行

/etc/letsencrypt/live/you.cn/fullchain.pem
/etc/letsencrypt/live/you.cn/privkey.pem

證書生成完成后可以到 /etc/letsencrypt/live/ 目錄下查看對應(yīng)域名的證書文件。編輯 nginx 配置文件監(jiān)聽 443 端口，啟用 SSL，并配置 SSL 的公鑰、私鑰證書路徑：

server {
   listen   443 ssl;
   server_name  you.cn;
   root /home/www/you;
   index  index.html index.htm index.php;

    ssl on;
    ssl_certificate /etc/letsencrypt/live/you.cn/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/you.cn/privkey.pem;
    ...
}

server {
    listen 80;
    server_name you.cn;
    location / {
        rewrite ^(.*)$  https://$host$1 permanent;
    }
}

配置好nginx后，重啟nginx

證書安裝成功后，該域名下的所有二級域名都可以使用噢

可以使用一下命令取消剛剛生成的密匙，也就是以上的反操作：

certbot revoke --cert-path /etc/letsencrypt/live/you.cn/cert.pem
certbot delete --cert-name you.cn

參考的網(wǎng)址有

https://sanonz.github.io/2017..."s-encrypt-free-ssl-https/

https://www.jianshu.com/p/c5c...

https://segmentfault.com/a/11...

https://www.jianshu.com/p/e32...

https://segmentfault.com/a/11...

https://segmentfault.com/a/11...

https://wp.wt629.com/archives...

https://www.yiichina.com/tuto...