https://docs.microsoft.com/zh-cn/azure/application-gateway/self-signed-certificates
https://stackoverflow.com/questions/21297139/how-do-you-sign-a-certificate-signing-request-with-your-certification-authority
https://docs.microsoft.com/zh-cn/azure/application-gateway/self-signed-certificates
https://stackoverflow.com/questions/21297139/how-do-you-sign-a-certificate-signing-request-with-your-certification-authority