Vấn đề bảo mật link khi LIVE STREAM trong NGINX-RTMP

http {
    server {
        listen 8080;
        server_name localhost;

        location /on_play {

            # set connection secure link
            secure_link $arg_st,$arg_e;
            secure_link_md5 mysecretkey$arg_app/$arg_name$arg_e;

            # bad hash
            if ($secure_link = "") {
                return 501;
            }

            # link expired
            if ($secure_link = "0") {
                return 502;
            }

            return 200;
        }
    }
}
rtmp {
    server {
        listen 1935;

        # protected application
        application myapp {
            live on;
            on_play http://localhost:8080/on_play;
        }
    }
}

With the above configuration you cannot play any stream from myapp application without providing the right secure link.

> ffplay 'rtmp://localhost/myapp/mystream'
ffplay version 1.0.6 Copyright (c) 2003-2013 the FFmpeg developers
...
rtmp://localhost/myapp/mystream: Unknown error occurred




In error.log we have this message

notify: HTTP retcode: 5xx




Now let’s construct valid secure RTMP link. Get current timestamp first and add 1 hour expire time to it.

> date +%s
1370777449
> echo $((1370777449+3600))
1370781049



Then construct the hash (watch config above for key)

> echo -n "mysecretkeymyapp/mystream1370781049" | openssl dgst -md5 -binary | 
         openssl enc -base64 | tr '+/' '-_' | tr -d '='
Mbjev5ld4mmCN00mwIqD7w



Now we have the hash. It’s easy to construct the valid secure RTMP url.

> ffplay 'rtmp://localhost/myapp/mystream?e=1370781049&st=Mbjev5ld4mmCN00mwIqD7w'




Source: https://rarut.wordpress.com/2013/06/09/secure-links-in-nginx-rtmp/