Refactor: replace deprecated 'binary' encoding with Buffer

[c3retc3]

As per the Node.js documentation, 'binary' encoding is outdated and can lead to unexpected behavior or data loss.

1. Replaced deprecated 'binary' string encoding with direct Buffer operations for data key handling.
2. The encrypt method now passes the dataKey buffer directly to crypto.update.
3. The decrypt method now correctly reconstructs the dataKey using Buffer.concat.

This improves code quality and future compatibility without altering the cryptographic logic.

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[gemini-code-assist]

Hello @c3retc3, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

Summary of Changes

Hello! Gemini here, providing a summary of this pull request. This PR, authored by c3retc3, aims to refactor the AESTransitCrypto class to eliminate the use of the deprecated 'binary' string encoding in Node.js. As noted in the description, using 'binary' encoding can lead to unexpected behavior or data loss. The changes involve modifying how the encrypted data key is handled during both encryption and decryption, transitioning from string manipulation with 'binary' encoding to direct Buffer operations. This improves code quality and aligns with current Node.js best practices without altering the core cryptographic logic.

Highlights

• Refactor Deprecated Encoding: Replaces the use of the deprecated 'binary' string encoding with direct Buffer handling for the encrypted data key.
• Improved Buffer Handling: Modifies the encrypt method to pass the data key as a Buffer directly to crypto.update and updates the decrypt method to reconstruct the decrypted data key using Buffer.concat from Buffer chunks returned by the crypto methods.
• Code Quality: Enhances code quality and future compatibility by adopting modern Node.js Buffer practices.

Changelog

• src/crypto/aes_transit_crypto.ts
  • In the encrypt method, removed the toString("binary") call on the data key and the corresponding 'binary' input encoding argument from the masterCipher.update call (line 23). The dataKey is now passed directly as a Buffer.
  • In the decrypt method, refactored the data key decryption logic (lines 53-56). Instead of concatenating 'binary' strings from masterCipher.update and masterCipher.final and then creating a Buffer, the methods are now called without an output encoding to return Buffers directly. These Buffer chunks are collected and concatenated using Buffer.concat to form the final byteKey Buffer.

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---

Old 'binary' string,
A source of bugs it would bring.
Buffers now take flight,
Making crypto feel right,
A cleaner, safer thing.

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[gemini-code-assist]

Code Review

This pull request effectively addresses the deprecation of the 'binary' encoding in Node.js by refactoring the data key handling to use direct Buffer operations. The changes in both the encrypt and decrypt methods are clear, correct, and improve the codebase's robustness and future compatibility. Well done on identifying and fixing this deprecated usage!

I have one suggestion for a minor improvement to enhance type safety.

Summary of Findings

• Explicit Typing for Array: In src/crypto/aes_transit_crypto.ts, the decryptedKeyChunks array could benefit from explicit typing (e.g., Buffer[]) for improved clarity and type safety, aligning with TypeScript best practices.

Merge Readiness

The pull request is well-structured and addresses an important deprecation. The core logic is sound. I've made one medium severity suggestion regarding explicit typing for better maintainability. Addressing this point would make the code even more robust.

As a reviewer, I am not authorized to approve pull requests. Please ensure this change is reviewed and approved by a maintainer before merging. I recommend addressing the suggested change before merging.

[c3retc3]

Explicitly declaring Buffer[] to prevent accidental pushes or incorrect types during maintenance

[c3retc3]

Hello everyone, could someone please take a look at this PR on deprecated 'binary' string encoding, or point me to the right reviewer?