在学习Linux的过程中，难免不犯错误。在Certbot申请证书的过程中，的确有时会犯中二病。
1.首先确认你的证书不再需要，如果有必要，请执行下面的命令进行备份
cp /etc/letsencrypt/ /etc/letsencrypt.backup -r
2.撤销证书
进入certbot目录，执行如下命令：
[root@rxblog certbot-0.22.2]# ./certbot-auto revoke --cert-path /etc/letsencrypt/archive/iwwenbo.com/cert1.pem
Saving debug log to /var/log/letsencrypt/letsencrypt.log
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Would you like to delete the cert(s) you just revoked?
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(Y)es (recommended)/(N)o: Y
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Deleted all files relating to certificate iwwenbo.com.
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Congratulations! You have successfully revoked the certificate that was located
at /etc/letsencrypt/archive/iwwenbo.com/cert1.pem
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3.删除证书
[root@rxblog certbot-0.22.2]# ./certbot-auto delete
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Which certificate(s) would you like to delete?
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1: rxblog.xyz
2: weiyanzixun.com
3: iwwenbo.com
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Select the appropriate numbers separated by commas and/or spaces, or leave input
blank to select all options shown (Enter 'c' to cancel): 3
-------------------------------------------------------------------------------
Deleted all files relating to certificate www.mydomain.com.
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选择你要进行删除的域名证书，用英文逗号”,”或者空格进行多个域名的分割；如果取消输入”c”。这样你需要删除的域名相关文件就删除了。