SSL certificate problem: certificate has expired

在执行curl https://stackoverflow.com/questions/5274934/use-ping-through-socks-server遇到这个报错的.

完整报错:

curl: (60) SSL certificate problem: certificate has expired
More details here: https://curl.haxx.se/docs/sslcerts.html

curl failed to verify the legitimacy of the server and therefore could not
establish a secure connection to it. To learn more about this situation and
how to fix it, please visit the web page mentioned above.

但是, 通过wireshark抓包分析.

似乎出错的不是本机(因为最后一条错误消息是本机发出去的), 而不是stackoverflow. 于是加上-k(insecure), 绕开这个问题了.

如果我的猜测不对, 恳请指证.