Secure Link Md5 Implementation

[anish10dec]

Any Update Please 
How to use two secret Keys for Secure Link Md5.

Primary to be used by application which is in production and secondary for
application build which has been  rolled out with changed secret key i.e.
secondary.
So that application should work in both scenario meanwhile till the all the
users update the application

Please help 
Inside location or server block

secure_link $arg_tok,$arg_e;
secure_link_md5 "primarysecret$arg_tok$arg_e";
secure_link_md5 "secondarysecret$arg_tok$arg_e";
if ($secure_link = "") {return 405;}
if ($secure_link = "0"){return 410;}

This gives error as secure link md5 is used twice within a location block

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,275668,276348#msg-276348