[WIP] ARMv8 Cryptography Extensions support

Adds a new backend which uses ARMv8 Cryptography Extensions.

These extensions are supported on both 32-bit and 64-bit ARM targets,
however the current implementation is gated on `aarch64` (as that's
the only architecture it's been tested on so far).

Presently only AES-128 is supported, but the code is written in such a
way it should be easy to expand to AES-192 and AES-256.

Author: tarcieri

.github/workflows/aes.yml

@@ -36,12 +36,12 @@ jobs:
           target: ${{ matrix.target }}
           profile: minimal
           override: true
-      - run: cargo check --all-features
+      - run: cargo check --features compact,ctr,force-soft
       - run: cargo build --release --target ${{ matrix.target }}
       - run: cargo build --release --target ${{ matrix.target }} --features compact
       - run: cargo build --release --target ${{ matrix.target }} --features ctr
       - run: cargo build --release --target ${{ matrix.target }} --features force-soft
-      - run: cargo build --release --target ${{ matrix.target }} --all-features
+      - run: cargo build --release --target ${{ matrix.target }} --features compact,ctr,force-soft
 
   # Tests for the AES-NI backend
   aesni:
@@ -79,7 +79,6 @@ jobs:
       - run: cargo test --release --target ${{ matrix.target }} --features compact
       - run: cargo test --release --target ${{ matrix.target }} --features ctr
       - run: cargo test --release --target ${{ matrix.target }} --features force-soft
-      - run: cargo test --release --target ${{ matrix.target }} --all-features
 
   # Tests for CPU feature autodetection with fallback to portable software implementation
   autodetect:
@@ -144,7 +143,7 @@ jobs:
       - run: cargo test --release --target ${{ matrix.target }} --features force-soft
       - run: cargo test --release --target ${{ matrix.target }} --features force-soft,compact
       - run: cargo test --release --target ${{ matrix.target }} --features force-soft,ctr
-      - run: cargo test --release --target ${{ matrix.target }} --all-features
+      - run: cargo build --release --target ${{ matrix.target }} --features compact,ctr,force-soft
 
   # Cross-compiled tests
   cross:
@@ -162,7 +161,6 @@ jobs:
             rust: 1.49.0 # MSRV
           - target: powerpc-unknown-linux-gnu
             rust: stable
-
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v1
@@ -178,4 +176,43 @@ jobs:
       - run: cross test --release --target ${{ matrix.target }} --features compact
       - run: cross test --release --target ${{ matrix.target }} --features ctr
       - run: cross test --release --target ${{ matrix.target }} --features force-soft
+      - run: cross test --release --target ${{ matrix.target }} --features compact,ctr,force-soft
+
+  # Nightly-only cross-compiled tests (for ARM64 intrinsics)
+  nightly:
+    strategy:
+      matrix:
+        include:
+          # ARM64
+          - target: aarch64-unknown-linux-gnu
+            rust: 1.49.0 # MSRV
+          - target: aarch64-unknown-linux-gnu
+            rust: stable
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - run: ${{ matrix.deps }}
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ matrix.rust }}
+          target: ${{ matrix.target }}
+          profile: minimal
+          override: true
+      - run: cargo install cross
+      - run: cross test --release --target ${{ matrix.target }}
+      - run: cross test --release --target ${{ matrix.target }} --features nightly,compact
+      - run: cross test --release --target ${{ matrix.target }} --features nightly,ctr
+      - run: cross test --release --target ${{ matrix.target }} --features nightly,force-soft
       - run: cross test --release --target ${{ matrix.target }} --all-features
+
+  clippy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: 1.49.0 # MSRV
+          components: clippy
+          override: true
+          profile: minimal
+      - run: cargo clippy --features compact,ctr,force-soft -- -D warnings

.github/workflows/workspace.yml

@@ -20,7 +20,7 @@ jobs:
         components: clippy
         override: true
         profile: minimal
-    - run: cargo clippy --all --all-features -- -D warnings
+    - run: cargo clippy --all --exclude aes --all-features -- -D warnings
 
   rustfmt:
     runs-on: ubuntu-latest

aes/Cargo.lock

@@ -27,8 +27,9 @@ cipher = { version = "0.3", features = ["dev"] }
 cpufeatures = "0.1"
 
 [features]
-compact = [] # Reduce code size at the cost of slower performance
+compact    = [] # Reduce code size at the cost of slower performance
 force-soft = [] # Disable support for AES hardware intrinsics
+nightly    = [] # Nightly compiler support; enables ARMv8 intrinsics
 
 [package.metadata.docs.rs]
 features = ["ctr"]