[ci] Upload checksum value for packages

[pandafy]

Since we have already added a functionality to upload packages directly to downloads.openwisp.io, it will be beneficial to also upload checksums for built packages.

This way users will be able to verify the authenticity of downloaded packages.

[nemesifier]

Here's how OpenWRT does it: https://downloads.openwrt.org/releases/21.02.0/packages/mips_24kc/packages/Packages

Would be great to do the same, including the checksum of our packages only.

[Dharansh-Neema]

I would like to give it a try. @pandafy

[Vihar214]

Hello, Is there anyone working on this issue if not then can you assign this issue to Me?

[devkapilbansal]

Hi @Dharansh-Neema @Vihar214 there is no need of assignment. Anyone of you can try and raised a pull request for this issue 🙃

[Joseph2001-braganza]

Hi Just one doubt before contributing to this issue for generating the checksum, is there a specific hashing algorithm like sha256 that I should be followed or any other one ? I have to update the config script so that it includes the Checksum field of every package am I right ?