Restructure cryptobackend packages

[qmuntal]

Goal

Restructure the cryptobackend layout and symbols so that they are more similar to the crypto/internal/fips140 packages. This is an important step towards leaving the Boringcrypto APIs behind.

Summary

• Restructure cryptobackend into per-algorithm packages and slim the root backend API
• Update stdlib integrations and vendored backend package list to use the package-specific APIs
• Add focused GitHub Actions workflows for patch application and Go tests in cryptobackend / eng/_util

Validation

• pwsh eng/run.ps1 submodule-refresh -shallow
• go test ./... in cryptobackend
• go test go/build -run TestDependencies in go/src
• go test -run=^$ crypto/internal/fips140only crypto/hmac crypto/hkdf crypto/pbkdf2 crypto/ecdsa crypto/rsa in go/src
• go test ./... in eng/_util

[Copilot]

Pull request overview

This PR restructures github.com/microsoft/go/cryptobackend into per-algorithm subpackages (e.g., aes, rsa, sha*, tls12, tls13) and trims the root backend package down to primarily enablement/FIPS gating, then updates integrations and CI workflows accordingly.

Changes:

• Split the cryptobackend surface area into algorithm-focused subpackages with platform-specific implementations and nobackend stubs.
• Update the TLS Microsoft policy patch to use package-specific capability checks (e.g., cryptobackend/ecdh, cryptobackend/mlkem) instead of the root API.
• Add a dedicated patch-apply workflow and change the main test workflow to run Go tests for cryptobackend and eng/_util.

Patches are happy!

Show a summary per file

File	Description
patches/0010-Align-TLS-settings-with-Microsoft-policies.patch	Updates TLS policy patch to use per-algorithm cryptobackend subpackages.
cryptobackend/README.md	Documents the new algorithm subpackage shape and intent.
cryptobackend/nobackend.go	Slims root package !systemcrypto stub to only enablement/FIPS gating.
cryptobackend/backend_linux.go	Slims root Linux backend to enablement/FIPS gating only.
cryptobackend/backend_windows.go	Slims root Windows backend to enablement/FIPS gating only.
cryptobackend/backend_darwin.go	Slims root Darwin backend to enablement/FIPS gating only.
cryptobackend/backend_msgostd.go	Wires stdlib-only FIPS approved-hash hook to the new cryptobackend/hash package.
cryptobackend/backend_test.go	Adds tests enforcing subpackages import the root backend package.
cryptobackend/bbig/init.go	Ensures the bbig subpackage triggers root backend init when imported.
cryptobackend/hash/hash_linux.go	Adds Linux implementation for approved-hash checks.
cryptobackend/hash/hash_windows.go	Adds Windows implementation for approved-hash checks.
cryptobackend/hash/hash_darwin.go	Adds Darwin implementation for approved-hash checks.
cryptobackend/hash/nobackend.go	Adds !systemcrypto stub for approved-hash checks.
cryptobackend/aes/aes_linux.go	Adds Linux AES block backend.
cryptobackend/aes/aes_windows.go	Adds Windows AES block backend.
cryptobackend/aes/aes_darwin.go	Adds Darwin AES block backend.
cryptobackend/aes/nobackend.go	Adds !systemcrypto AES stub.
cryptobackend/aes/init.go	Ensures AES subpackage triggers root backend init.
cryptobackend/aes/gcm/gcm_linux.go	Adds Linux GCM (TLS/TLS13) backend.
cryptobackend/aes/gcm/gcm_windows.go	Adds Windows GCM (TLS/TLS13) backend.
cryptobackend/aes/gcm/gcm_darwin.go	Adds Darwin GCM (TLS/TLS13) backend.
cryptobackend/aes/gcm/nobackend.go	Adds !systemcrypto GCM stub.
cryptobackend/aes/gcm/init.go	Ensures GCM subpackage triggers root backend init.
cryptobackend/chacha20poly1305/chacha20poly1305_linux.go	Adds Linux ChaCha20-Poly1305 backend with FIPS-only gating.
cryptobackend/chacha20poly1305/chacha20poly1305_windows.go	Adds Windows ChaCha20-Poly1305 backend with FIPS-only gating.
cryptobackend/chacha20poly1305/chacha20poly1305_darwin.go	Adds Darwin ChaCha20-Poly1305 backend with FIPS-only gating.
cryptobackend/chacha20poly1305/nobackend.go	Adds !systemcrypto ChaCha20-Poly1305 stub.
cryptobackend/chacha20poly1305/init.go	Ensures ChaCha20-Poly1305 subpackage triggers root backend init.
cryptobackend/des/des_linux.go	Adds Linux DES/3DES backend.
cryptobackend/des/des_windows.go	Adds Windows DES/3DES backend.
cryptobackend/des/des_darwin.go	Adds Darwin DES/3DES backend.
cryptobackend/des/nobackend.go	Adds !systemcrypto DES/3DES stub.
cryptobackend/des/init.go	Ensures DES subpackage triggers root backend init.
cryptobackend/rc4/rc4_linux.go	Adds Linux RC4 backend.
cryptobackend/rc4/rc4_windows.go	Adds Windows RC4 backend.
cryptobackend/rc4/rc4_darwin.go	Adds Darwin RC4 backend.
cryptobackend/rc4/nobackend.go	Adds !systemcrypto RC4 stub.
cryptobackend/rc4/init.go	Ensures RC4 subpackage triggers root backend init.
cryptobackend/drbg/rand_linux.go	Adds Linux DRBG/random reader wrapper.
cryptobackend/drbg/rand_windows.go	Adds Windows DRBG/random reader wrapper.
cryptobackend/drbg/rand_darwin.go	Adds Darwin DRBG/random reader wrapper.
cryptobackend/drbg/nobackend.go	Adds !systemcrypto DRBG stub.
cryptobackend/drbg/init.go	Ensures DRBG subpackage triggers root backend init.
cryptobackend/hmac/hmac_linux.go	Adds Linux HMAC backend.
cryptobackend/hmac/hmac_windows.go	Adds Windows HMAC backend.
cryptobackend/hmac/hmac_darwin.go	Adds Darwin HMAC backend.
cryptobackend/hmac/nobackend.go	Adds !systemcrypto HMAC stub.
cryptobackend/hmac/init.go	Ensures HMAC subpackage triggers root backend init.
cryptobackend/hkdf/hkdf.go	Adds shared HKDF composition helper.
cryptobackend/hkdf/hkdf_linux.go	Adds Linux HKDF backend.
cryptobackend/hkdf/hkdf_windows.go	Adds Windows HKDF backend.
cryptobackend/hkdf/hkdf_darwin.go	Adds Darwin HKDF backend.
cryptobackend/hkdf/nobackend.go	Adds !systemcrypto HKDF stub.
cryptobackend/hkdf/init.go	Ensures HKDF subpackage triggers root backend init.
cryptobackend/pbkdf2/pbkdf2_linux.go	Adds Linux PBKDF2 backend.
cryptobackend/pbkdf2/pbkdf2_windows.go	Adds Windows PBKDF2 backend.
cryptobackend/pbkdf2/pbkdf2_darwin.go	Adds Darwin PBKDF2 backend.
cryptobackend/pbkdf2/nobackend.go	Adds !systemcrypto PBKDF2 stub.
cryptobackend/pbkdf2/init.go	Ensures PBKDF2 subpackage triggers root backend init.
cryptobackend/md5/md5_linux.go	Adds Linux MD5 backend.
cryptobackend/md5/md5_windows.go	Adds Windows MD5 backend.
cryptobackend/md5/md5_darwin.go	Adds Darwin MD5 backend.
cryptobackend/md5/nobackend.go	Adds !systemcrypto MD5 stub.
cryptobackend/md5/init.go	Ensures MD5 subpackage triggers root backend init.
cryptobackend/sha1/sha1_linux.go	Adds Linux SHA-1 backend.
cryptobackend/sha1/sha1_windows.go	Adds Windows SHA-1 backend.
cryptobackend/sha1/sha1_darwin.go	Adds Darwin SHA-1 backend.
cryptobackend/sha1/nobackend.go	Adds !systemcrypto SHA-1 stub.
cryptobackend/sha1/init.go	Ensures SHA-1 subpackage triggers root backend init.
cryptobackend/sha256/sha256_linux.go	Adds Linux SHA-224/SHA-256 backend.
cryptobackend/sha256/sha256_windows.go	Adds Windows SHA-256 backend (with SHA-224 unsupported).
cryptobackend/sha256/sha256_darwin.go	Adds Darwin SHA-256 backend (with SHA-224 unsupported).
cryptobackend/sha256/nobackend.go	Adds !systemcrypto SHA-256/SHA-224 stub.
cryptobackend/sha256/init.go	Ensures SHA-256 subpackage triggers root backend init.
cryptobackend/sha512/sha512_linux.go	Adds Linux SHA-384/SHA-512 and SHA-512/224,/256 backend.
cryptobackend/sha512/sha512_windows.go	Adds Windows SHA-384/SHA-512 backend (with /224,/256 unsupported).
cryptobackend/sha512/sha512_darwin.go	Adds Darwin SHA-384/SHA-512 backend (with /224,/256 unsupported).
cryptobackend/sha512/nobackend.go	Adds !systemcrypto SHA-512 family stub.
cryptobackend/sha512/init.go	Ensures SHA-512 subpackage triggers root backend init.
cryptobackend/sha3/sha3_linux.go	Adds Linux SHA-3/SHAKE/CSHAKE backend.
cryptobackend/sha3/sha3_windows.go	Adds Windows SHA-3/SHAKE backend (with SHA3-224 unsupported).
cryptobackend/sha3/sha3_darwin.go	Adds Darwin SHA-3 backend with partial SHAKE support.
cryptobackend/sha3/nobackend.go	Adds !systemcrypto SHA-3/SHAKE stub types and functions.
cryptobackend/sha3/init.go	Ensures SHA-3 subpackage triggers root backend init.
cryptobackend/ecdh/ecdh_linux.go	Adds Linux ECDH backend.
cryptobackend/ecdh/ecdh_windows.go	Adds Windows ECDH backend.
cryptobackend/ecdh/ecdh_darwin.go	Adds Darwin ECDH backend.
cryptobackend/ecdh/nobackend.go	Adds !systemcrypto ECDH stub.
cryptobackend/ecdh/init.go	Ensures ECDH subpackage triggers root backend init.
cryptobackend/ecdsa/ecdsa_linux.go	Adds Linux ECDSA backend.
cryptobackend/ecdsa/ecdsa_windows.go	Adds Windows ECDSA backend (with stdlib signature marshal/unmarshal glue).
cryptobackend/ecdsa/ecdsa_darwin.go	Adds Darwin ECDSA backend.
cryptobackend/ecdsa/nobackend.go	Adds !systemcrypto ECDSA stub.
cryptobackend/ecdsa/init.go	Ensures ECDSA subpackage triggers root backend init.
cryptobackend/rsa/rsa_linux.go	Adds Linux RSA backend with FIPS-dependent key-size constraints.
cryptobackend/rsa/rsa_windows.go	Adds Windows RSA backend.
cryptobackend/rsa/rsa_darwin.go	Adds Darwin RSA backend with stdlib key encode/decode glue.
cryptobackend/rsa/nobackend.go	Adds !systemcrypto RSA stub.
cryptobackend/rsa/init.go	Ensures RSA subpackage triggers root backend init.
cryptobackend/rsa/rsa_test.go	Adds RSA support tests for the new RSA subpackage API.
cryptobackend/dsa/dsa_linux.go	Adds Linux DSA backend.
cryptobackend/dsa/dsa_windows.go	Adds Windows DSA backend.
cryptobackend/dsa/dsa_darwin.go	Adds Darwin DSA stubs (unsupported).
cryptobackend/dsa/nobackend.go	Adds !systemcrypto DSA stub.
cryptobackend/dsa/init.go	Ensures DSA subpackage triggers root backend init.
cryptobackend/ed25519/ed25519_linux.go	Adds Linux Ed25519 backend.
cryptobackend/ed25519/ed25519_windows.go	Adds Windows Ed25519 stubs (unsupported).
cryptobackend/ed25519/ed25519_darwin.go	Adds Darwin Ed25519 backend.
cryptobackend/ed25519/nobackend.go	Adds !systemcrypto Ed25519 stub.
cryptobackend/ed25519/init.go	Ensures Ed25519 subpackage triggers root backend init.
cryptobackend/mlkem/mlkem_linux.go	Adds Linux ML-KEM backend.
cryptobackend/mlkem/mlkem_windows.go	Adds Windows ML-KEM backend.
cryptobackend/mlkem/mlkem_darwin.go	Adds Darwin ML-KEM backend.
cryptobackend/mlkem/nobackend.go	Adds !systemcrypto ML-KEM stub.
cryptobackend/mlkem/init.go	Ensures ML-KEM subpackage triggers root backend init.
cryptobackend/mldsa/mldsa_linux.go	Adds Linux ML-DSA backend.
cryptobackend/mldsa/mldsa_windows.go	Adds Windows ML-DSA backend.
cryptobackend/mldsa/mldsa_darwin.go	Adds Darwin ML-DSA backend with partial parameter support.
cryptobackend/mldsa/nobackend.go	Adds !systemcrypto ML-DSA stub.
cryptobackend/mldsa/init.go	Ensures ML-DSA subpackage triggers root backend init.
cryptobackend/tls12/tls12_linux.go	Adds Linux TLS 1.2 PRF backend.
cryptobackend/tls12/tls12_windows.go	Adds Windows TLS 1.2 PRF backend.
cryptobackend/tls12/tls12_darwin.go	Adds Darwin TLS 1.2 PRF stubs (unsupported).
cryptobackend/tls12/nobackend.go	Adds !systemcrypto TLS 1.2 PRF stub.
cryptobackend/tls12/init.go	Ensures TLS 1.2 subpackage triggers root backend init.
cryptobackend/tls13/tls13_linux.go	Adds Linux TLS 1.3 KDF backend.
cryptobackend/tls13/tls13_windows.go	Adds Windows TLS 1.3 KDF stubs (unsupported).
cryptobackend/tls13/tls13_darwin.go	Adds Darwin TLS 1.3 KDF stubs (unsupported).
cryptobackend/tls13/nobackend.go	Adds !systemcrypto TLS 1.3 KDF stub.
cryptobackend/tls13/init.go	Ensures TLS 1.3 subpackage triggers root backend init.
.github/workflows/test.yml	Reworks CI to run go test for cryptobackend and eng/_util.
.github/workflows/patch-apply.yml	Adds dedicated workflow to verify patches apply cleanly.

Copilot's findings

• Files reviewed: 132/134 changed files
• Comments generated: 9