Rips purchased pornography off r18.com. Downloads the chunks, appropriate decryption key, and modifies the chunklist.
THIS DOES NOT DECRYPT DUE TO UNKNOWN ISSUES. ffmpeg or vlc should be able to put the pieces together for you.
r18rip <playlist URL> [--bitrate <integer>]
ex.
r18rip https://cflstc.r18.com/r18/st1:REDACTED/-/cdn/playlist.m3u8?ld=REDACTED
Immediately after setting the bitrate in the r18 web player (auto works too, this just chooses the highest bitrate unless you specify otherwise), the first m3u8 requested by your browser, playlist.m3u8 is what this wants.
Though, if you specify the second followup one, chunklist_xxxxx.m3u8, this can handle it too.
NOTE: So far as I can tell, these URIs are auth tokens in themselves. Do not share them with others.