Kraker Local Proxy Server -- Instruction Manual


This manual is not complete. Only critical information relevant to Alleycat Player is presented at this time. The manual will be updated with more details for those who are interested in using the proxy server for their own purposes.


File access permissions - the Kraker security model

The proxy server implements a security model in order to prevent unauthorized access to files on the local drive. Alleycat Player is normally restricted by the web browser from freely accessing the file system but this limit can be bypassed via the proxy server. These basic rules are applied for file access:

1) All files in the Alleycat directory are accessible for reading.
2) A new file can be opened for writing but it is not permitted to modify an existing file.
3) No access at all is possible outside of the Alleycat root directory.

It is sometimes desirable to read files located elsewhere on the local drive (to play a video, for example). Also, Alleycat Player has a new feature for saving m3u8 videos and this requires the ability to append to an existing file in order to concatenate the segments. This is not allowed under the basic rules. A special file called "_aliases.txt" is employed to control file access. If you intend to save m3u8 videos, you need to learn this. File path names are not permitted. You must use an alias. The syntax for an entry in the aliases file is simple:

+alias, +c:/myfolder/myvideo.mp4;

White space is irrelevant and you may include whatever comments you like in the file. The proxy server looks for a given name in between a plus sign and a comma. If the name is found, then the proxy will look for a path name in between a plus sign and a semicolon. To enable a file for writing, put a question mark at the end of the alias (in front of the comma). The alias may not contain a colon or a slash or a backslash.

A file called "_aliases_sample.txt" is provided with the Alleycat installation. This file should be renamed as "_aliases.txt". It contains 18 preset aliases for the purpose of saving m3u8 videos. Each video uses two aliases, one for an audio track (where applicable) and one for the video track.

Note that "_aliases.txt" is blocked for both reading and writing. File reading is implemented via the GET method in a standard HTTP request. Files may be created or appended via the PUT method. No other mechanism has been provided for accessing the file system. This is not intended as a replacement for standard file access.


List of Alleycat Player files:

kraker.js Proxy Server
alleycat-player.htm Alleycat Player
crypto.js cryptography module https://cdnjs.cloudflare.com/ajax/libs/crypto-js/3.1.9-1/crypto-js.min.js
hls_player.js HLS/m3u8 player module https://cdn.jsdelivr.net/npm/hls.js@0.12.0/dist/hls.min.js
dash_player.js DASH/mpd player module https://reference.dashif.org/dash.js/v2.9.3/dist/dash.all.min.js
poster.jpg background image

List of supplementary files:

_aliases.txt file access permissions
_blank_dash_mpd.txt template for Youtube DASH
_blank_live_mpd.txt template for Youtube DASH
_https_crt.pem HTTPS certificate
_https_key.pem HTTPS private key


Go to the Alleycat Player instruction manual.