[WIP] crypto-common: migrate to hybrid-array; MSRV 1.65

Replaces `generic-array` with `hybrid-array`, which is built on a
combination of `typenum` and const generics, providing a degree of
interoperability between the two systems.

`hybrid-array` is designed to be a largely drop-in replacement, and the
number of changes required to switch are relatively minimal aside from
some idiosyncracies.

.github/workflows/crypto-common.yml

@@ -22,7 +22,7 @@ jobs:
     strategy:
       matrix:
         rust:
-          - 1.56.0 # MSRV
+          - 1.65.0 # MSRV
           - stable
         target:
           - thumbv7em-none-eabi
@@ -46,7 +46,7 @@ jobs:
     strategy:
       matrix:
         rust:
-          - 1.56.0 # MSRV
+          - 1.65.0 # MSRV
           - stable
     steps:
       - uses: actions/checkout@v3

crypto-common/Cargo.toml

@@ -13,7 +13,7 @@ keywords = ["crypto", "traits"]
 categories = ["cryptography", "no-std"]
 
 [dependencies]
-generic-array = { version = "0.14.6", features = ["more_lengths"] }
+hybrid-array = "=0.2.0-pre.2"
 typenum = "1.14" # earlier versions of typenum don't satisfy the 'static bound on U* types
 
 # optional dependencies

crypto-common/README.md

@@ -2,10 +2,10 @@
 
 [![crate][crate-image]][crate-link]
 [![Docs][docs-image]][docs-link]
+[![Build Status][build-image]][build-link]
 ![Apache2/MIT licensed][license-image]
 ![Rust Version][rustc-image]
 [![Project Chat][chat-image]][chat-link]
-[![Build Status][build-image]][build-link]
 
 Common traits used by cryptographic algorithms. Users should generally use
 higher-level trait crates instead of this one.
@@ -14,7 +14,7 @@ higher-level trait crates instead of this one.
 
 ## Minimum Supported Rust Version
 
-Rust **1.56** or higher.
+Rust **1.65** or higher.
 
 Minimum supported Rust version can be changed in the future, but it will be
 done with a minor version bump.
@@ -46,7 +46,7 @@ dual licensed as above, without any additional terms or conditions.
 [docs-image]: https://docs.rs/crypto-common/badge.svg
 [docs-link]: https://docs.rs/crypto-common/
 [license-image]: https://img.shields.io/badge/license-Apache2.0/MIT-blue.svg
-[rustc-image]: https://img.shields.io/badge/rustc-1.56+-blue.svg
+[rustc-image]: https://img.shields.io/badge/rustc-1.65+-blue.svg
 [chat-image]: https://img.shields.io/badge/zulip-join_chat-blue.svg
 [chat-link]: https://rustcrypto.zulipchat.com/#narrow/stream/260041-hashes
 [build-image]: https://github.com/RustCrypto/traits/workflows/crypto-common/badge.svg?branch=master&event=push

crypto-common/src/lib.rs

@@ -15,28 +15,28 @@ extern crate std;
 #[cfg(feature = "rand_core")]
 pub use rand_core;
 
-pub use generic_array;
-pub use generic_array::typenum;
+pub use hybrid_array as array;
+pub use typenum;
 
 use core::fmt;
-use generic_array::{typenum::Unsigned, ArrayLength, GenericArray};
+use hybrid_array::{typenum::Unsigned, Array, ArraySize, ByteArray};
 #[cfg(feature = "rand_core")]
 use rand_core::CryptoRngCore;
 
 /// Block on which [`BlockSizeUser`] implementors operate.
-pub type Block<B> = GenericArray<u8, <B as BlockSizeUser>::BlockSize>;
+pub type Block<B> = ByteArray<<B as BlockSizeUser>::BlockSize>;
 
 /// Parallel blocks on which [`ParBlocksSizeUser`] implementors operate.
-pub type ParBlocks<T> = GenericArray<Block<T>, <T as ParBlocksSizeUser>::ParBlocksSize>;
+pub type ParBlocks<T> = Array<Block<T>, <T as ParBlocksSizeUser>::ParBlocksSize>;
 
 /// Output array of [`OutputSizeUser`] implementors.
-pub type Output<T> = GenericArray<u8, <T as OutputSizeUser>::OutputSize>;
+pub type Output<T> = ByteArray<<T as OutputSizeUser>::OutputSize>;
 
 /// Key used by [`KeySizeUser`] implementors.
-pub type Key<B> = GenericArray<u8, <B as KeySizeUser>::KeySize>;
+pub type Key<B> = ByteArray<<B as KeySizeUser>::KeySize>;
 
 /// Initialization vector (nonce) used by [`IvSizeUser`] implementors.
-pub type Iv<B> = GenericArray<u8, <B as IvSizeUser>::IvSize>;
+pub type Iv<B> = ByteArray<<B as IvSizeUser>::IvSize>;
 
 /// Types which process data in blocks.
 pub trait BlockSizeUser {
@@ -59,12 +59,12 @@ impl<T: BlockSizeUser> BlockSizeUser for &mut T {
 }
 
 /// Trait implemented for supported block sizes, i.e. for types from `U1` to `U255`.
-pub trait BlockSizes: ArrayLength<u8> + sealed::BlockSizes + 'static {}
+pub trait BlockSizes: ArraySize + sealed::BlockSizes + 'static {}
 
-impl<T: ArrayLength<u8> + sealed::BlockSizes> BlockSizes for T {}
+impl<T: ArraySize + sealed::BlockSizes> BlockSizes for T {}
 
 mod sealed {
-    use generic_array::typenum::{Gr, IsGreater, IsLess, Le, NonZero, Unsigned, U1, U256};
+    use typenum::{Gr, IsGreater, IsLess, Le, NonZero, Unsigned, U1, U256};
 
     pub trait BlockSizes {}
 
@@ -80,13 +80,13 @@ mod sealed {
 /// Types which can process blocks in parallel.
 pub trait ParBlocksSizeUser: BlockSizeUser {
     /// Number of blocks which can be processed in parallel.
-    type ParBlocksSize: ArrayLength<Block<Self>>;
+    type ParBlocksSize: ArraySize;
 }
 
 /// Types which return data with the given size.
 pub trait OutputSizeUser {
     /// Size of the output in bytes.
-    type OutputSize: ArrayLength<u8> + 'static;
+    type OutputSize: ArraySize + 'static;
 
     /// Return output size in bytes.
     #[inline(always)]
@@ -100,7 +100,7 @@ pub trait OutputSizeUser {
 /// Generally it's used indirectly via [`KeyInit`] or [`KeyIvInit`].
 pub trait KeySizeUser {
     /// Key size in bytes.
-    type KeySize: ArrayLength<u8> + 'static;
+    type KeySize: ArraySize + 'static;
 
     /// Return key size in bytes.
     #[inline(always)]
@@ -114,7 +114,7 @@ pub trait KeySizeUser {
 /// Generally it's used indirectly via [`KeyIvInit`] or [`InnerIvInit`].
 pub trait IvSizeUser {
     /// Initialization vector size in bytes.
-    type IvSize: ArrayLength<u8> + 'static;
+    type IvSize: ArraySize + 'static;
 
     /// Return IV size in bytes.
     #[inline(always)]
@@ -151,11 +151,9 @@ pub trait KeyInit: KeySizeUser + Sized {
     /// Create new value from variable size key.
     #[inline]
     fn new_from_slice(key: &[u8]) -> Result<Self, InvalidLength> {
-        if key.len() != Self::KeySize::to_usize() {
-            Err(InvalidLength)
-        } else {
-            Ok(Self::new(Key::<Self>::from_slice(key)))
-        }
+        <&Key<Self>>::try_from(key)
+            .map(Self::new)
+            .map_err(|_| InvalidLength)
     }
 
     /// Generate random key using the provided [`CryptoRngCore`].
@@ -177,16 +175,9 @@ pub trait KeyIvInit: KeySizeUser + IvSizeUser + Sized {
     /// Create new value from variable length key and nonce.
     #[inline]
     fn new_from_slices(key: &[u8], iv: &[u8]) -> Result<Self, InvalidLength> {
-        let key_len = Self::KeySize::USIZE;
-        let iv_len = Self::IvSize::USIZE;
-        if key.len() != key_len || iv.len() != iv_len {
-            Err(InvalidLength)
-        } else {
-            Ok(Self::new(
-                Key::<Self>::from_slice(key),
-                Iv::<Self>::from_slice(iv),
-            ))
-        }
+        let key = <&Key<Self>>::try_from(key).map_err(|_| InvalidLength)?;
+        let iv = <&Iv<Self>>::try_from(iv).map_err(|_| InvalidLength)?;
+        Ok(Self::new(key, iv))
     }
 
     /// Generate random key using the provided [`CryptoRngCore`].
@@ -237,11 +228,8 @@ pub trait InnerIvInit: InnerUser + IvSizeUser + Sized {
     /// Initialize value using `inner` and `iv` slice.
     #[inline]
     fn inner_iv_slice_init(inner: Self::Inner, iv: &[u8]) -> Result<Self, InvalidLength> {
-        if iv.len() != Self::IvSize::to_usize() {
-            Err(InvalidLength)
-        } else {
-            Ok(Self::inner_iv_init(inner, Iv::<Self>::from_slice(iv)))
-        }
+        let iv = <&Iv<Self>>::try_from(iv).map_err(|_| InvalidLength)?;
+        Ok(Self::inner_iv_init(inner, iv))
     }
 
     /// Generate random IV using the provided [`CryptoRngCore`].