[vcsjones]

This implements AES-KW.

1. protected virtual's implementation is built using the existing AES-KW wrapping methods, which is built on top of AES-ECB.
2. The Apple implementation overrides it and uses CryptoKit, when available. That is macOS 12+ and iOS / tvOS 15+. For macOS, all supported versions can use the CryptoKit implementation. For iOS 13-14, the base managed implementation is used as a fallback. Otherwise CryptoKit is used.
3. OpenSSL uses the OpenSSL implementation, which is present on all supported OpenSSL. This re-uses much of the OpenSSL implementation as we did for AES-KWP. Given the difficulties we had getting that working I am inclined to use as much of the existing functionality there as possible.

Windows has no native implementation currently so it uses the managed implementation.

The diff for this is a tad yucky. AesKeyWrapTests.cs got renamed to AesKeyWrapPaddedTests.cs, and the AesKeyWrapTests.cs became the file with the unpadded variant. Open to suggestions to make this less blah.

Closes #130490

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Pull request overview

Adds support for RFC 3394 AES Key Wrap (AES-KW) to System.Security.Cryptography.Aes, including managed fallback logic plus platform-specific acceleration on Apple (CryptoKit) and OpenSSL, along with updated/expanded test coverage and known-answer vectors.

Changes:

• Introduces new Aes.EncryptKeyWrap* / Aes.DecryptKeyWrap* APIs (and GetKeyWrapLength) and a managed RFC3394 implementation path.
• Wires up native support for AES-KW on OpenSSL and Apple (Swift/CryptoKit + managed interop).
• Splits padded vs unpadded test coverage into separate files and adds RFC 3394 KATs + tamper/validation tests.

Show a summary per file

File	Description
src/libraries/System.Security.Cryptography/src/System/Security/Cryptography/Aes.cs	Adds RFC3394 public API surface and managed core implementation.
src/libraries/System.Security.Cryptography/ref/System.Security.Cryptography.cs	Declares the new public Aes AES-KW APIs in the reference contract.
src/libraries/System.Security.Cryptography/src/System/Security/Cryptography/AesImplementation.OpenSsl.cs	Implements AES-KW via OpenSSL EVP wrap ciphers.
src/libraries/System.Security.Cryptography/src/System/Security/Cryptography/AesImplementation.Apple.cs	Implements AES-KW via CryptoKit when available; falls back to base implementation otherwise.
src/libraries/Common/src/Interop/Unix/System.Security.Cryptography.Native/Interop.EVP.Cipher.cs	Adds P/Invokes for EVP AES wrap (unpadded) ciphers.
src/native/libs/System.Security.Cryptography.Native/pal_evp_cipher.h	Declares new native exports for EVP AES wrap (unpadded) ciphers.
src/native/libs/System.Security.Cryptography.Native/pal_evp_cipher.c	Implements new native exports for EVP AES wrap (unpadded) ciphers.
src/native/libs/System.Security.Cryptography.Native/opensslshim.h	Adds required OpenSSL symbols for EVP AES wrap (unpadded).
src/native/libs/System.Security.Cryptography.Native/entrypoints.c	Registers new CryptoNative entrypoints for AES wrap (unpadded).
src/native/libs/System.Security.Cryptography.Native.Apple/pal_swiftbindings.swift	Adds Swift-exported CryptoKit AES-KW wrap/unwrap entrypoints.
src/native/libs/System.Security.Cryptography.Native.Apple/pal_swiftbindings.h	Adds AppleCryptoNative symbol declarations for AES-KW entrypoints.
src/native/libs/System.Security.Cryptography.Native.Apple/entrypoints.c	Registers new AppleCryptoNative entrypoints for AES-KW.
src/libraries/Common/src/Interop/OSX/System.Security.Cryptography.Native.Apple/Interop.AesKeyWrap.cs	Adds managed interop wrappers for Apple CryptoKit AES-KW entrypoints.
src/libraries/System.Security.Cryptography/src/System.Security.Cryptography.csproj	Includes new Apple interop source file in the library build.
src/libraries/System.Security.Cryptography/src/Resources/Strings.resx	Adds new resource strings for RFC3394 key wrap length validation errors.
src/libraries/System.Security.Cryptography/tests/System.Security.Cryptography.Tests.csproj	Includes new split test file for padded key wrap.
src/libraries/System.Security.Cryptography/tests/ShimHelpers.cs	Updates shim override verification to include new virtual core methods.
src/libraries/Common/tests/System/Security/Cryptography/AlgorithmImplementations/AES/KeyWrapTests.cs	Converts/expands tests for unpadded RFC3394 key wrap, including KATs and tamper tests.
src/libraries/Common/tests/System/Security/Cryptography/AlgorithmImplementations/AES/KeyWrapPaddedTests.cs	New file containing the padded (RFC5649) tests after rename/split.

Review details

• Files reviewed: 19/19 changed files
• Comments generated: 2
• Review effort level: Lite

[Copilot]

Review details

• Files reviewed: 19/19 changed files
• Comments generated: 2
• Review effort level: Lite

[Copilot]

Review details

• Files reviewed: 19/19 changed files
• Comments generated: 3
• Review effort level: Lite

[vcsjones]

/ba-g failure is #132336

[bartonjs]

/backport to release/11.0-rc1

[github-actions]

Started backporting to release/11.0-rc1 (link to workflow run)