No encryption method for xchacha20-ietf-poly1305

[hamzamalikdevgalixo]

There is no support for xchacha20-ietf-poly1305. golang.org/x/crypto/ has support for this. Is there any update going on regarding this

[amircybersec]

@hamzamalikdevgalixo may I ask what server you are using with Outline client? As far as Outline server supports all client side (app) encryptions. Please let me know if you have any suggestions on code snippets that show how this can be added to the SDK.

[amircybersec]

@hamzamalikdevgalixo are you using xray or singbox on the server side?

[hamzamalikdevgalixo]

We are using shadowsocks-libev on the server side

[amircybersec]

@hamzamalikdevgalixo Looking at the spec, seems like these three crypto are part of the spec:

https://shadowsocks.org/doc/aead.html

May I ask why not use one of the supported encryption methods? Is there any obvious advantage in using xchacha20-ietf-poly1305 or is it just for maximum compatibility?

[hamzamalikdevgalixo]

Yes it has support for those but I'm looking for maximum compatibility. I don't want to change the infrastructure setup that's done and its working well in our other platform as well.

[amircybersec]

@hamzamalikdevgalixo it seems like other shadowsocks implementations are deprecating xchacha20-ietf-poly1305. It is not clear why (mostly for simplification, maintenance, and performance I guess)

shadowsocks/shadowsocks-android#2697

Maybe others can chime in and see if it is a good idea to add it to SDK or there is a good reason not to.

[fortuna]

xchacha20-ietf-poly1305 seems to be an abandoned IETF proposal: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-xchacha-03

We would like to stick to the standard crypto. Support for alternative ciphers may open up the code to vulnerabilities. I strongly recommend moving away from that cipher in favor for the IETF ones.