I have a strange situation here.
Sending a HTTP-POST (Angular app) to a webserver (Apache2 and CGI-Script in Perl). The POST-parameter is ~110k of size. Content is a Base64 string (atob in the webapp).
At a special location (~48.5k) there is a +. The only one in the B64 string - what makes me suspicious. If I decode it in the app again all is fine. But I need to send it to the server.
But what the CGI-script is receiving is a " " (blank) instead of the + at the location mentioned. The rest is exactly the same.
The Base64 decoding does not work then because " " is not in the alphabet of Base64.
Any idea what is going on here?
I cant reproduce it with a random string. Further, the connection is secured so I can not dump the transport-package.