ssl certificate - php7.0.15 issues about ssl

Question

1. What has been changed about phpssl certificate verification?
2. What happened:
2.1: When I opened the system I wrote before today, I found an inexplicable error SSL operation failed with code 1. OpenSSL Error messages :
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
So I searched for a long time and checked the manual but couldn't find it. I wonder if it's because I'm blind - -
3. I would like to ask if you know what rules have been changed in the SSL certificate. Could you please Can you explain it?
4: I lazily used the file_get_contents function to achieve remote access and then reported this error when accessing the WeChat api interface.

5. Temporarily abandon the communication of whether to use curl or file. My purpose is to find out what changes were made that caused the error in the SSL certificate. After all, the previous version did not An error occurred

openissl is enabled

Answer 1

It should be that the server PHP extension openssl is not enabled. If you cannot open that server, you can use curl instead, do not use file_get_contents