> For the complete documentation index, see [llms.txt](https://doc.tanmer.cn/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.tanmer.cn/ubuntu/openssl-shi-yong-ji-qiao.md).

# OpenSSL 使用技巧

## 查看证书信息

```bash
openssl x509 -in ca.crt -noout -text
```

## 查看在线域名的证书信息

```bash
openssl s_client -connect ms.icometrix.com:443 -cipher 'DEFAULT:!ECDH'
```