Migrate to official BouncyCastle.Cryptography

[skibitsky]

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Status	Type	⚠️ Core Change	Issue
Draft	Refactor	?	Link

Problem

Solana.Unity-Core relies on a deprecated unofficial fork of the BouncyCastle cryptography library, Portable.BouncyCastle, which hasn't been updated for ~5 years.

There're 3 vulnerability found in the original version of the old BouncyCastle library:

In addition to the potential security risk, it introduces a dependency conflict in Unity with third-party packages that use the official BouncyCastle library.

Solution

Upgrade to the official library, BouncyCastle.Cryptography, which is now compatible with .NET Standard, meaning it works in Unity.

Other changes (e.g. bug fixes, small refactors)

• Minor culture conversion fixes in unit tests

Deploy Notes

Notes regarding deployment of the contained body of work. These should note any
new dependencies, new scripts, etc.

New dependencies:

• BouncyCastle.Cryptography