Tip function

[crossle]

No description provided.

[Copilot]

Pull request overview

This PR refactors the TipNode code to use a simpler ByteArray-based API instead of the Scalar object API from the tip library, simplifying the cryptographic key handling.

Changes:

• Replaced Scalar object usage with ByteArray for private keys throughout TipNode
• Updated Tip library method calls to use new ByteArray-based functions (newPrivateKeyFromBytes, publicKeyFromBytes, signFromBytes, etc.)
• Fixed list subtraction operation by converting to Set before subtraction
• Changed a variable from var to val in Tip.kt for immutability

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 3 comments.

File	Description
app/src/main/java/one/mixin/android/tip/TipNode.kt	Refactored to use ByteArray instead of Scalar for private key handling, updated all Tip library method calls, removed clone() call, fixed list subtraction
app/src/main/java/one/mixin/android/tip/Tip.kt	Changed local variable from var to val for better immutability

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[Copilot]

The conversion here appears inefficient. The code converts a ByteArray to hex string and then back to a private key format (userSk.toHex() -> privateKeyFromHex()). Since userSk is already in ByteArray format, consider whether the Tip library provides a decrypt method that accepts ByteArray directly, or if newPrivateKeyFromBytes already returns the correct format that can be used directly with decrypt. This round-trip conversion may be unnecessary and impacts performance.

Suggested change

	val plain = Tip.decrypt(signerPk, Tip.privateKeyFromHex(userSk.toHex()), resp.data.cipher.hexStringToByteArray())
	val plain = Tip.decrypt(
	signerPk,
	Tip.newPrivateKeyFromBytes(userSk),
	resp.data.cipher.hexStringToByteArray(),
	)

[Copilot]

The conversion here appears inefficient. The code converts a ByteArray to hex string and then back to a private key format (userSk.toHex() -> privateKeyFromHex()). Since userSk is already in ByteArray format, consider whether the Tip library provides an encrypt method that accepts ByteArray directly, or if newPrivateKeyFromBytes already returns the correct format that can be used directly with encrypt. This round-trip conversion may be unnecessary and impacts performance.

Suggested change

	val cipher = Tip.encrypt(signerPk, Tip.privateKeyFromHex(userSk.toHex()), dataJson)
	val cipher = Tip.encrypt(signerPk, Tip.newPrivateKeyFromBytes(userSk), dataJson)

[Copilot]

The removal of clone() here could be problematic if the Tip library functions modify the ByteArray in place. The userSk ByteArray is being passed to multiple concurrent async coroutines (one for each signer), and if any of the Tip library methods (signFromBytes, encrypt, decrypt, etc.) modify the ByteArray, this could lead to race conditions or corrupted data. Consider whether userSk needs to be cloned for each async operation to ensure thread safety, or verify that all Tip library methods treat the ByteArray as immutable.

Suggested change

	val (sign, tipNodeError) = signTipNode(userSk, signer, ephemeral, watcher, nonce + retryCount, grace, assignee)
	val (sign, tipNodeError) = signTipNode(userSk.clone(), signer, ephemeral, watcher, nonce + retryCount, grace, assignee)

[Copilot]

Pull request overview

Copilot reviewed 2 out of 3 changed files in this pull request and generated no new comments.

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