Backpack sign message implementation

[dfl-zeke]

Is your feature request related to a problem? Please describe.
I want to sign messages with backpack, because when I build my project with xNFT, I'm not able to sign in users.

Describe the solution you'd like
Implement _SignTransaction function inside XNFTWallet.cs

Describe alternatives you've considered
The only alternative to this function is to use signTransaction and make user sign memo transaction and don't send it, use it for validation only, which is not the best solution, it's already used by Ledger users but not convenient one, since backpack supports sign message.

Additional context
I've written implementation for it, but problem is, that Phantom.jslib uses window.phantom.solana.request function, which returns signature as a string, but other wallet adapters does not return string, return UInt8Array. For consistency, we must return Uint8Array from phantom wallet adapter as well.

If you have any other ideas how we can implement it, I can do it for sure.

[GabrielePicco]

@dfl-zeke thanks for opening the issue, we just added the support for the Solana Wallet Adapter in the latest version, Backpack should also support it, I just need to confirm that it works from an xnft as well and will move the implementation to the new standard. Sign is supported as well.
Here is the issue for reference: #82 (comment)

[GabrielePicco]

Also, just to confirm, the method you need is SignMessage, is that correct?

[dfl-zeke]

Also, just to confirm, the method you need is SignMessage, is that correct?

Yes, I use Web3.Base.SignMessage and it returns that the method is not implemented.

[GabrielePicco]

Noted thanks, yes it needs to be added here: https://github.com/magicblock-labs/Solana.Unity-SDK/blob/main/Runtime/Plugins/xNFT.jslib#L37 and here: https://github.com/magicblock-labs/Solana.Unity-SDK/blob/main/Runtime/codebase/XNFTWallet.cs#L59 . Adding it to the pipeline, if you have it working feel free to open a PR.

[dfl-zeke]

Noted thanks, yes it needs to be added here: https://github.com/magicblock-labs/Solana.Unity-SDK/blob/main/Runtime/Plugins/xNFT.jslib#L37 and here: https://github.com/magicblock-labs/Solana.Unity-SDK/blob/main/Runtime/codebase/XNFTWallet.cs#L59 . Adding it to the pipeline, if you have it working feel free to open a PR.

I can add it right now, but there is one issue. As I've explained above, in Phantom.jslib uses window.phantom.solana.request to signMessage, instead of window.phantom.solana.signMessage. Because of that, phantom returns signature as base58 string (here: https://github.com/magicblock-labs/Solana.Unity-SDK/blob/main/Runtime/Plugins/Phantom.jslib#L51 signedMessage is base58 string) and other wallet adapters (including backpack) only have signMessage, which returns UInt8Array. Don't you think we should change this in Phantom.jslib as well? I can make backpack signMessage return base58 string instead of Uint8Array for sure, but don't think it's correct way to do so.

[GabrielePicco]

Shouldn't be a problem @dfl-zeke , as long as XNFTWallet.cs overrides SignMessage with signature: override Task<byte[]> SignMessage(byte[] message), it will implement the IWalletBase interface. Phantom.jslib and xNFT.jslib are never used directly, so can internally be different.
Also, Phantom.jslib will soon be deprecated in favour of SolanaWalletAdapterWebGL, which is the general solana adapter.

[dfl-zeke]

Shouldn't be a problem @dfl-zeke , as long as XNFTWallet.cs overrides SignMessage with signature: override Task<byte[]> SignMessage(byte[] message), it will implement the IWalletBase interface. Phantom.jslib and xNFT.jslib are never used directly, so can internally be different. Also, Phantom.jslib will soon be deprecated in favour of SolanaWalletAdapterWebGL, which is the general solana adapter.

Ah yes, you're right. Done the implementation. LMK if there is any issue with my code.

[GabrielePicco]

Closing as #86 has been merged! Thanks @dfl-zeke for the contribution 🚀