6.4. 在 CLI 中查看证书的到期日期

流程

• 使用 openssl 实用程序以人类可读格式打开文件：

  $ openssl x509 -noout -text -in ca.pem
  Certificate:
      Data:
          Version: 3 (0x2)
          Serial Number: 1 (0x1)
          Signature Algorithm: sha256WithRSAEncryption
          Issuer: O = IDM.EXAMPLE.COM, CN = Certificate Authority
          Validity
              Not Before: Oct 30 19:39:14 2017 GMT
              Not After : Oct 30 19:39:14 2037 GMT