feat(picky-crypto): add the RustCrypto backend

.github/workflows/ci.yml

@@ -227,18 +227,45 @@ jobs:
         run: cargo --locked xtask check-vectors
 
       - name: Run conformance suite
-        run: cargo test --locked -p picky-crypto-conformance -- --show-output
+        run: cargo test --locked -p picky-crypto-conformance --features rustcrypto -- --show-output
 
       - name: Install cargo-deny
         run: cargo install --locked cargo-deny --version 0.20.2
 
       - name: Check dependency allowlist
         run: cargo deny --manifest-path picky-crypto/Cargo.toml --config picky-crypto/deny.toml check bans
 
+  picky-crypto-rustcrypto:
+    name: RustCrypto backend checks
+    needs: [formatting]
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          submodules: true
+
+      - name: Install cargo-hack
+        run: cargo install --locked cargo-hack --version 0.6.45
+
+      - name: Check feature powerset
+        run: cargo hack clippy --locked --feature-powerset --depth 2 -p picky-crypto-rustcrypto --all-targets -- -D warnings
+
+      - name: Check documentation
+        run: cargo doc --locked -p picky-crypto-rustcrypto --no-deps --all-features
+        env:
+          RUSTDOCFLAGS: "-D warnings"
+
+      - name: Install cargo-deny
+        run: cargo install --locked cargo-deny --version 0.20.2
+
+      - name: Check banned features
+        run: cargo deny --manifest-path Cargo.toml --workspace --all-features --config picky-crypto-rustcrypto/deny.toml check bans
+
   success:
     name: Success
     if: ${{ always() }}
-    needs: [formatting, lints, lints-wasm, tests, msrv, dotnet-tests, no-downgrade, picky-crypto-checks]
+    needs: [formatting, lints, lints-wasm, tests, msrv, dotnet-tests, no-downgrade, picky-crypto-checks, picky-crypto-rustcrypto]
     runs-on: ubuntu-latest
 
     steps:

Cargo.toml

@@ -6,6 +6,7 @@ members = [
     "picky-crypto",
     "picky-crypto-testsuite",
     "picky-crypto-conformance",
+    "picky-crypto-rustcrypto",
     "picky",
     "picky-krb",
     "picky-asn1",
@@ -17,6 +18,7 @@ members = [
 
 default-members = [
     "picky-crypto",
+    "picky-crypto-rustcrypto",
     "picky",
     "picky-krb",
     "picky-asn1",

picky-crypto-conformance/Cargo.toml

@@ -15,6 +15,12 @@ name = "conformance"
 path = "tests/main.rs"
 harness = true
 
+[features]
+rustcrypto = ["dep:picky-crypto-rustcrypto"]
+
+[dependencies]
+picky-crypto-rustcrypto = { path = "../picky-crypto-rustcrypto", features = ["all"], optional = true }
+
 [dev-dependencies]
 picky-crypto = { path = "../picky-crypto" }
 picky-crypto-testsuite = { path = "../picky-crypto-testsuite" }

picky-crypto-conformance/tests/main.rs

@@ -102,6 +102,8 @@ fn empty() -> CryptoProvider {
 
 providers! {
     empty ("none") => empty(), Options::default();
+    #[cfg(feature = "rustcrypto")]
+    rustcrypto ("rustcrypto") => picky_crypto_rustcrypto::provider(), Options::default();
 }
 
 pairs! {

picky-crypto-rustcrypto/AGENTS.md

@@ -0,0 +1,7 @@
+# Backend maintenance
+
+- Inline tests cover adapter logic only: argument mapping, length and constant-byte checks.
+  Do not retest behavior covered by the conformance suite or the library.
+- Never modify `picky-crypto-testsuite` to make this backend pass.
+  Escalate a failing case with its cited source, vector identifier, expected outcome and native library behavior.
+- Cite the source file or documentation page at the version locked in `Cargo.lock` when relying on a library capability, or mark it Unknown.

picky-crypto-rustcrypto/Cargo.toml

@@ -0,0 +1,59 @@
+[package]
+name = "picky-crypto-rustcrypto"
+version = "0.1.0"
+edition = "2024"
+publish = false
+rust-version = "1.85"
+authors = ["Devolutions Inc. <infos@devolutions.net>"]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/Devolutions/picky-rs"
+description = "RustCrypto backend for the picky cryptographic provider contract"
+readme = "README.md"
+keywords = ["cryptography", "provider", "crypto"]
+categories = ["cryptography"]
+
+[features]
+digest = ["dep:sha1", "dep:sha2", "dep:sha3", "dep:hmac", "dep:pbkdf2", "dep:digest", "dep:crypto-common"]
+aes = ["dep:aes", "dep:cbc", "dep:cipher"]
+aead = ["dep:aes-gcm", "dep:aes", "dep:getrandom", "dep:crypto-common"]
+key-wrap = ["dep:aes-kw", "dep:aes"]
+rsa = ["dep:rsa", "dep:md-5", "dep:sha1", "dep:sha2", "dep:sha3", "dep:getrandom", "dep:chacha20", "dep:crypto-common"]
+nist-ec = ["dep:p256", "dep:p384", "dep:p521", "dep:sha2", "dep:hmac", "dep:getrandom", "dep:crypto-common", "dep:sec1"]
+curve25519 = ["dep:ed25519-dalek", "dep:ed25519", "dep:x25519-dalek", "dep:sha2", "dep:getrandom", "dep:crypto-common"]
+legacy = ["dep:md4", "dep:md-5", "dep:rc4", "dep:des", "dep:rc2", "dep:cbc", "dep:cipher", "dep:digest"]
+all = ["digest", "aes", "aead", "key-wrap", "rsa", "nist-ec", "curve25519", "legacy"]
+
+[dependencies]
+picky-crypto = { path = "../picky-crypto" }
+zeroize = { version = "1.9", default-features = false, features = ["alloc"] }
+crypto-common = { version = "0.2.2", optional = true, features = ["rand_core", "zeroize"] }
+aes = { version = "0.9.2", optional = true, features = ["zeroize"] }
+aes-gcm = { version = "0.11.1", optional = true, default-features = false, features = ["aes", "alloc", "rand_core", "zeroize"] }
+aes-kw = { version = "0.3.1", optional = true, features = ["zeroize"] }
+cbc = { version = "0.2.1", optional = true, default-features = false, features = ["zeroize"] }
+cipher = { version = "0.5.2", optional = true, features = ["zeroize"] }
+digest = { version = "0.11.3", optional = true, features = ["zeroize"] }
+des = { version = "0.9.0", optional = true, features = ["zeroize"] }
+rc2 = { version = "0.9.0", optional = true, features = ["zeroize"] }
+rc4 = { version = "0.2.0", optional = true, features = ["zeroize"] }
+md4 = { version = "0.11.0", optional = true, features = ["zeroize"] }
+md-5 = { version = "0.11.0", optional = true, features = ["oid", "zeroize"] }
+sha1 = { version = "0.11.0", optional = true, features = ["oid", "zeroize"] }
+sha2 = { version = "0.11.0", optional = true, features = ["oid", "zeroize"] }
+sha3 = { version = "0.12.0", optional = true, features = ["oid", "zeroize"] }
+hmac = { version = "0.13.0", optional = true, features = ["zeroize"] }
+pbkdf2 = { version = "0.13.0", optional = true, default-features = false, features = ["hmac"] }
+rsa = { version = "=0.10.0-rc.18", optional = true }
+chacha20 = { version = "0.10.2", optional = true, default-features = false, features = ["rng", "zeroize"] }
+sec1 = { version = "0.8.1", optional = true, default-features = false, features = ["der", "zeroize"] }
+p256 = { version = "0.14.0", optional = true, default-features = false, features = ["ecdsa", "ecdh", "pkcs8", "alloc", "precomputed-tables", "std"] }
+p384 = { version = "0.14.0", optional = true, default-features = false, features = ["ecdsa", "ecdh", "pkcs8", "alloc", "precomputed-tables", "std"] }
+p521 = { version = "0.14.0", optional = true, default-features = false, features = ["ecdsa", "ecdh", "pkcs8", "alloc", "precomputed-tables", "std"] }
+ed25519-dalek = { version = "3.0.0", optional = true, default-features = false, features = ["alloc", "digest", "fast", "pkcs8", "rand_core", "zeroize"] }
+ed25519 = { version = "3.0.0", optional = true, default-features = false, features = ["pkcs8", "zeroize"] }
+x25519-dalek = { version = "3.0.0", optional = true, default-features = false, features = ["precomputed-tables", "static_secrets", "zeroize"] }
+getrandom = { version = "0.4.3", optional = true, features = ["sys_rng"] }
+
+[dev-dependencies]
+# Test keys outside the library's checked constructors (small moduli, large exponents).
+rsa = { version = "=0.10.0-rc.18", features = ["hazmat"] }

picky-crypto-rustcrypto/INTENT.md

@@ -0,0 +1,15 @@
+# picky-crypto-rustcrypto
+
+## Purpose
+
+`picky-crypto` backend implemented on top of the RustCrypto crates.
+
+It implements every algorithm of the contract that RustCrypto provides when the `all` feature is enabled, including legacy algorithms (MD4, MD5, RC4, 3DES, RC2) needed by NTLM, Kerberos and legacy PKCS#12.
+No family is enabled by default; each feature adds a family of entries.
+
+## Invariants
+
+- A backend is a thin adapter.
+  Real logic in a backend means the contract doesn't fit that library, and that's a reason to revisit the contract.
+- It passes the full `picky-crypto-testsuite` conformance suite.
+- `fips()` always returns `false`.