Feature request: Add Argon2id support

Argon2id is currently recommended by OWASP for password hashing and standardized in RFC 9106.

It would be useful to have an official Argon2id implementation in SymCrypt, especially since .NET currently has no built-in Argon2 support and generally relies on platform cryptographic implementations rather than implementing cryptographic primitives itself.

In dotnet/runtime discussion #117822, the .NET team explained that currently only OpenSSL provides Argon2, while Windows CNG and Apple CryptoKit/CommonCrypto do not. They also noted that support on at least two platforms is generally expected before adding such an algorithm to System.Security.Cryptography.

There is also a long-standing request for Argon2 support in dotnet/runtime#19933.

Adding Argon2id to SymCrypt could therefore help enable first-party support in the Windows cryptography stack and eventually System.Security.Cryptography / ASP.NET Core Identity, while avoiding reliance on third-party cryptographic implementations.

Would Argon2id support be something the SymCrypt team would consider?

The issue names no files, tests, or entry points, and asks whether the SymCrypt team would consider Argon2id support. Start by reviewing SymCrypt's existing algorithm APIs and contribution guidance, then clarify the supported platforms, API shape, test requirements, and acceptance criteria before implementation can begin.