crt格式转pem
openssl x509 -in www.x.com.crt -out www.x.com.pem
openssl x509 -in mycert.crt -out mycert.pem -outform PEM
openssl x509 -inform DER -in yourdownloaded.crt -out outcert.pem -text
openssl x509 -in mycert.crt -out mycert.pem -outform PE重命名
我们可以直接把fullchain.pem重命名为“fullchain.crt
把privkey.pem重命名为privkey.key