Add support for other encryption / decryption methods supported by discord

[Kaydax]

Is your feature request related to a problem? Please describe.
Currently DPP only supports xsalsa20_poly1305, however discord supports all of these other types:

• aead_aes256_gcm_rtpsize
• aead_aes256_gcm
• aead_xchacha20_poly1305_rtpsize
• xsalsa20_poly1305_lite_rtpsize
• xsalsa20_poly1305_lite
• xsalsa20_poly1305_suffix

Describe the solution you'd like
I would like to see all modes supported, or at least rtpsize be implemented.

There is full documentation on how rtpsize works here: https://git.kaydax.xyz/w/algos/src/branch/main/doc/crypt.md

Describe alternatives you've considered
None

Additional context
This has also been implemented into BetterDisco here: elderlabs/BetterDisco@d988d6a8

[braindigitalis]

we cant use that example code and really we shouldnt even look at it - it is LGPL 3.0 only.
Similarly we should not reference betterdiscord or any unofficial client fork. I'm sure we can figure something out though.

[Kaydax]

we cant use that example code and really we shouldnt even look at it - it is LGPL 3.0 only. Similarly we should not reference betterdiscord or any unofficial client fork. I'm sure we can figure something out though.

I removed the link to the example code from algos because of the license, however the crypt documentation is CC-BY-SA meaning its allowed to be used. Also BetterDisco is not a client modification, its a continuation of disco, the discord bot python library made by b1nzy

[Kaydax]

We just relicensed the code that is referenced in the docs to be LGPL OR Apache 2.0, so there is no longer any licensing problems: https://git.kaydax.xyz/w/algos/src/branch/main/src/module/util/crypt_impl.cc

[braindigitalis]

great to hear :D