我无法使用 wget 或 curl 打开任何 https URL：
$ wget https://www.python.org
--2015-04-27 17:17:33-- https://www.python.org/
Resolving www.python.org (www.python.org)... 103.245.222.223
Connecting to www.python.org (www.python.org)|103.245.222.223|:443... connected.
ERROR: cannot verify www.python.org's certificate, issued by "/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 Extended Validation Server CA":
Unable to locally verify the issuer's authority.
To connect to www.python.org insecurely, use '--no-check-certificate'.
$ curl https://www.python.org
curl: (60) SSL certificate problem: unable to get local issuer certificate
More details here: http://curl.haxx.se/docs/sslcerts.html
curl performs SSL certificate verification by default, using a "bundle"
of Certificate …