SSL Error: Unable to verify the first certificate

background ：

The client program interfaces to the background ( The use of https) launch get perhaps post request , All will report wrong. , But there is no problem accessing through the website , After repeated tests, it was found that ssl Certificate authentication failed ,postman Ignore ssl Certificate verification can be accessed successfully , If certificate verification is enabled, access will fail .

Solution ：

You can modify the client , Turn off the certificate verification function , but Because the client has given it to the client , Therefore, you can only modify the server , terms of settlement ： take ssl Of cer Document modified to pem, No need to pass openssl To deal with it , Only need to cer The suffix to pem Just go , So far, the problem has been solved .

See below for solutions ：
https://blog.csdn.net/weixin_43650943/article/details/122230219