ocb3: import from offset-codebook-mode crate (#587)

Import from https://github.com/sgmenda/offset-cookbook-mode

Includes modifications and consistency cleanups

---------

Co-authored-by: sanketh <me@snkth.com>
Co-authored-by: Tony Arcieri <bascule@gmail.com>

.github/workflows/ocb3.yml

@@ -0,0 +1,68 @@
+name: ocb3
+
+on:
+  pull_request:
+    paths:
+      - ".github/workflows/ocb3.yml"
+      - "ocb3/**"
+      - "Cargo.*"
+  push:
+    branches: master
+
+defaults:
+  run:
+    working-directory: ocb3
+
+env:
+  CARGO_INCREMENTAL: 0
+  RUSTFLAGS: "-Dwarnings"
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+          - 1.60.0 # MSRV
+          - stable
+        target:
+          - armv7a-none-eabi
+          - thumbv7em-none-eabi
+          - wasm32-unknown-unknown
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ matrix.rust }}
+          targets: ${{ matrix.target }}
+      - run: cargo build --no-default-features --release --target ${{ matrix.target }}
+
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        include:
+          # 32-bit Linux
+          - target: i686-unknown-linux-gnu
+            rust: 1.60.0 # MSRV
+            deps: sudo apt update && sudo apt install gcc-multilib
+          - target: i686-unknown-linux-gnu
+            rust: stable
+            deps: sudo apt update && sudo apt install gcc-multilib
+
+          # 64-bit Linux
+          - target: x86_64-unknown-linux-gnu
+            rust: 1.60.0 # MSRV
+          - target: x86_64-unknown-linux-gnu
+            rust: stable
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ matrix.rust }}
+          targets: ${{ matrix.target }}
+      - run: ${{ matrix.deps }}
+      - run: cargo test --target ${{ matrix.target }} --release
+      - run: cargo test --target ${{ matrix.target }} --release --features stream,std,zeroize
+      - run: cargo test --target ${{ matrix.target }} --release --all-features
+      - run: cargo build --target ${{ matrix.target }} --benches

Cargo.toml

@@ -9,5 +9,6 @@ members = [
     "deoxys",
     "eax",
     "mgm",
+    "ocb3",
 ]
 resolver = "2"

ocb3/CHANGELOG.md

@@ -0,0 +1,10 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+
+## 0.1.0 (2023-XX-XX)
+
+- Initial release

ocb3/Cargo.toml

@@ -0,0 +1,42 @@
+[package]
+name = "ocb3"
+version = "0.1.0"
+description = """
+Pure Rust implementation of the OCB3
+Authenticated Encryption with Associated Data (AEAD) Cipher
+"""
+authors = ["RustCrypto Developers"]
+edition = "2021"
+license = "Apache-2.0 OR MIT"
+readme = "README.md"
+documentation = "https://docs.rs/ocb3"
+repository = "https://github.com/RustCrypto/AEADs"
+keywords = ["aead", "encryption", "ocb", "ocb3"]
+categories = ["cryptography", "no-std"]
+rust-version = "1.60"
+
+[dependencies]
+aead = { version = "0.5", default-features = false }
+cipher = "0.4"
+ctr = "0.9"
+subtle = { version = "2", default-features = false }
+zeroize = { version = "1", optional = true, default-features = false }
+
+[dev-dependencies]
+aead = { version = "0.5", features = ["dev"], default-features = false }
+aes = { version = "0.8", default-features = false }
+hex-literal = "0.4"
+
+[features]
+default   = ["alloc", "getrandom"]
+std       = ["aead/std", "alloc"]
+alloc     = ["aead/alloc"]
+arrayvec  = ["aead/arrayvec"]
+getrandom = ["aead/getrandom", "rand_core"]
+heapless  = ["aead/heapless"]
+rand_core = ["aead/rand_core"]
+stream    = ["aead/stream"]
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]