curl: (35) error:1408F10B:SSL routines:ssl3_get_record:wrong version number

* Uses proxy env variable http_proxy == 'https://proxy.in.tum.de:8080'   
                                         ^^^^^

The https:// is wrong, it should be http://. The proxy itself should be accessed by HTTP and not HTTPS even though the target URL is HTTPS. The proxy will nevertheless properly handle HTTPS connection and keep the end-to-end encryption. See HTTP CONNECT method for details how this is done.

If anyone is getting this error using Nginx, try adding the following to your server config:

server {
    listen 443 ssl;
    ...
}

The issue stems from Nginx serving an HTTP server to a client expecting HTTPS on whatever port you're listening on. When you specify ssl in the listen directive, you clear this up on the server side.

Simple answer

If you are behind a proxy server, please set the proxy for curl. The curl is not able to connect to server so it shows wrong version number. Set proxy by opening subl ~/.curlrc or use any other text editor. Then add the following line to file: proxy= proxyserver:proxyport For e.g. proxy = 10.8.0.1:8080

If you are not behind a proxy, make sure that the curlrc file does not contain the proxy settings.