Fix Equals for cryptographic wrappers

[vcsjones]

The internal cryptographic wrapper, ECDsaWrapper, RSAWrapper, ECDiffieHellmanWrapper, and DSAWrapper implemented Equals in such a way that it was never going to be true. It delegated equals to "what was wrapped", but since you can't get what is wrapped out, you would end up comparing a wrapper to a wrapped.

This violated FDG 8.9.1

DO comply with the contract defined for Object.Equals when overriding the method.
For convenience, the contract taken directly from the System.Object documentation is provided here.

• x.Equals(x) returns true.

Excerpt From
Framework Design Guidelines

Instead, let's let wrappers compare what is being wrapped.

Fixes #118701

[Copilot]

Pull Request Overview

This PR fixes a fundamental issue with the Equals method implementation in cryptographic wrapper classes (RSAWrapper, ECDsaWrapper, and ECDiffieHellmanWrapper), which violated the Object.Equals contract by never returning true for self-comparison.

Key changes:

• Updated Equals method in all three wrapper classes to properly compare the wrapped instances when both objects are wrappers
• Added comprehensive unit tests to verify correct equality behavior for all cryptographic factory methods

Reviewed Changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
RSAWrapper.cs	Fixed Equals implementation to compare wrapped instances when both objects are RSAWrapper
ECDsaWrapper.cs	Fixed Equals implementation to compare wrapped instances when both objects are ECDsaWrapper
ECDiffieHellmanWrapper.cs	Fixed Equals implementation to compare wrapped instances when both objects are ECDiffieHellmanWrapper
RSAFactoryTests.cs	Added tests verifying RSA instances satisfy reflexive equality and different instances are not equal
ECDsaFactoryTests.cs	Added tests verifying ECDsa instances satisfy reflexive equality and different instances are not equal
ECDiffieHellmanFactoryTests.cs	Added tests verifying ECDiffieHellman instances satisfy reflexive equality and different instances are not equal
*.Tests.csproj	Updated test project files to include the new factory test files

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[vcsjones]

A final, final possible solution is to not do anything and say "Cryptographic primitives are like NaN!"

No? Bad idea? Okay.

[skyoxZ]

One more:

runtime/src/libraries/System.Security.Cryptography/src/System/Security/Cryptography/DSAWrapper.cs

Line 153 in f53ffe6

public override bool Equals(object? obj) => _wrapped.Equals(obj);

[vcsjones]

One more:

runtime/src/libraries/System.Security.Cryptography/src/System/Security/Cryptography/DSAWrapper.cs

Line 153 in f53ffe6

public override bool Equals(object? obj) => _wrapped.Equals(obj);

Thanks!

[bartonjs]

Looks good aside from one copy/paste/bad-edit