cipher: v0.3 changes (#435)

- remove `SeekNum` impls for signed integers
- fix block mode compilation bug
- change `SeekNum` impls to fit with the new `BlockBuffer`
- return `SeenNum` impl for `i32`
- re-export `blobby` from root
- reorganize modules

Co-authored-by: Артём Павлов [Artyom Pavlov] <newpavlov@gmail.com>

cipher/src/block.rs

@@ -9,21 +9,17 @@
 //! [1]: https://en.wikipedia.org/wiki/Block_cipher
 //! [2]: https://en.wikipedia.org/wiki/Symmetric-key_algorithm
 
-#[cfg(feature = "dev")]
-#[cfg_attr(docsrs, doc(cfg(feature = "dev")))]
-pub mod dev;
-
 use crate::errors::InvalidLength;
 use core::convert::TryInto;
 use generic_array::{typenum::Unsigned, ArrayLength, GenericArray};
 
 /// Key for an algorithm that implements [`NewBlockCipher`].
-pub type Key<B> = GenericArray<u8, <B as NewBlockCipher>::KeySize>;
+pub type BlockCipherKey<B> = GenericArray<u8, <B as NewBlockCipher>::KeySize>;
 
 /// Block on which a [`BlockCipher`] operates.
 pub type Block<B> = GenericArray<u8, <B as BlockCipher>::BlockSize>;
 
-/// Blocks being acted over in parallel.
+/// Block on which a [`BlockCipher`] operates in parallel.
 pub type ParBlocks<B> = GenericArray<Block<B>, <B as BlockCipher>::ParBlocks>;
 
 /// Instantiate a [`BlockCipher`] algorithm.
@@ -32,13 +28,13 @@ pub trait NewBlockCipher: Sized {
     type KeySize: ArrayLength<u8>;
 
     /// Create new block cipher instance from key with fixed size.
-    fn new(key: &Key<Self>) -> Self;
+    fn new(key: &BlockCipherKey<Self>) -> Self;
 
     /// Create new block cipher instance from key with variable size.
     ///
     /// Default implementation will accept only keys with length equal to
     /// `KeySize`, but some ciphers can accept range of key lengths.
-    fn new_varkey(key: &[u8]) -> Result<Self, InvalidLength> {
+    fn new_var(key: &[u8]) -> Result<Self, InvalidLength> {
         if key.len() != Self::KeySize::to_usize() {
             Err(InvalidLength)
         } else {
@@ -57,7 +53,7 @@ pub trait BlockCipher {
     type ParBlocks: ArrayLength<Block<Self>>;
 }
 
-/// Encrypt-only functionality for block ciphers
+/// Encrypt-only functionality for block ciphers.
 pub trait BlockEncrypt: BlockCipher {
     /// Encrypt block in-place
     fn encrypt_block(&self, block: &mut Block<Self>);
@@ -94,7 +90,7 @@ pub trait BlockEncrypt: BlockCipher {
     }
 }
 
-/// Decrypt-only functionality for block ciphers
+/// Decrypt-only functionality for block ciphers.
 pub trait BlockDecrypt: BlockCipher {
     /// Decrypt block in-place
     fn decrypt_block(&self, block: &mut Block<Self>);

cipher/src/common.rs

@@ -0,0 +1,79 @@
+use crate::{errors::InvalidLength, BlockCipher, NewBlockCipher};
+use generic_array::{typenum::Unsigned, ArrayLength, GenericArray};
+
+/// Key for an algorithm that implements [`NewCipher`].
+pub type CipherKey<C> = GenericArray<u8, <C as NewCipher>::KeySize>;
+
+/// Nonce for an algorithm that implements [`NewCipher`].
+pub type Nonce<C> = GenericArray<u8, <C as NewCipher>::NonceSize>;
+
+/// Cipher creation trait.
+///
+/// It can be used for creation of block modes, synchronous and asynchronous stream ciphers.
+pub trait NewCipher: Sized {
+    /// Key size in bytes
+    type KeySize: ArrayLength<u8>;
+
+    /// Nonce size in bytes
+    type NonceSize: ArrayLength<u8>;
+
+    /// Create new stream cipher instance from variable length key and nonce.
+    fn new(key: &CipherKey<Self>, nonce: &Nonce<Self>) -> Self;
+
+    /// Create new stream cipher instance from variable length key and nonce.
+    #[inline]
+    fn new_var(key: &[u8], nonce: &[u8]) -> Result<Self, InvalidLength> {
+        let kl = Self::KeySize::to_usize();
+        let nl = Self::NonceSize::to_usize();
+        if key.len() != kl || nonce.len() != nl {
+            Err(InvalidLength)
+        } else {
+            let key = GenericArray::from_slice(key);
+            let nonce = GenericArray::from_slice(nonce);
+            Ok(Self::new(key, nonce))
+        }
+    }
+}
+
+/// Trait for types which can be initialized from a block cipher and nonce.
+pub trait FromBlockCipher {
+    /// Block cipher
+    type BlockCipher: BlockCipher;
+    /// Nonce size in bytes
+    type NonceSize: ArrayLength<u8>;
+
+    /// Instantiate a stream cipher from a block cipher
+    fn from_block_cipher(
+        cipher: Self::BlockCipher,
+        nonce: &GenericArray<u8, Self::NonceSize>,
+    ) -> Self;
+}
+
+impl<C> NewCipher for C
+where
+    C: FromBlockCipher,
+    C::BlockCipher: NewBlockCipher,
+{
+    type KeySize = <<Self as FromBlockCipher>::BlockCipher as NewBlockCipher>::KeySize;
+    type NonceSize = <Self as FromBlockCipher>::NonceSize;
+
+    fn new(key: &CipherKey<Self>, nonce: &Nonce<Self>) -> C {
+        C::from_block_cipher(
+            <<Self as FromBlockCipher>::BlockCipher as NewBlockCipher>::new(key),
+            nonce,
+        )
+    }
+
+    fn new_var(key: &[u8], nonce: &[u8]) -> Result<Self, InvalidLength> {
+        if nonce.len() != Self::NonceSize::USIZE {
+            Err(InvalidLength)
+        } else {
+            C::BlockCipher::new_var(key)
+                .map_err(|_| InvalidLength)
+                .map(|cipher| {
+                    let nonce = GenericArray::from_slice(nonce);
+                    Self::from_block_cipher(cipher, nonce)
+                })
+        }
+    }
+}

cipher/src/dev.rs

@@ -0,0 +1,2 @@
+mod block;
+mod stream;

cipher/src/block/dev.rs → cipher/src/dev/block.rs

@@ -9,13 +9,13 @@ macro_rules! block_cipher_test {
     ($name:ident, $test_name:expr, $cipher:ty) => {
         #[test]
         fn $name() {
-            use cipher::block::{
-                dev::blobby::Blob3Iterator, BlockCipher, BlockDecrypt, BlockEncrypt, NewBlockCipher,
-            };
             use cipher::generic_array::{typenum::Unsigned, GenericArray};
+            use cipher::{
+                blobby::Blob3Iterator, BlockCipher, BlockDecrypt, BlockEncrypt, NewBlockCipher,
+            };
 
             fn run_test(key: &[u8], pt: &[u8], ct: &[u8]) -> bool {
-                let state = <$cipher as NewBlockCipher>::new_varkey(key).unwrap();
+                let state = <$cipher as NewBlockCipher>::new_var(key).unwrap();
 
                 let mut block = GenericArray::clone_from_slice(pt);
                 state.encrypt_block(&mut block);
@@ -37,7 +37,7 @@ macro_rules! block_cipher_test {
                 type Block = GenericArray<u8, BlockSize>;
                 type ParBlock = GenericArray<Block, ParBlocks>;
 
-                let state = <$cipher as NewBlockCipher>::new_varkey(key).unwrap();
+                let state = <$cipher as NewBlockCipher>::new_var(key).unwrap();
 
                 let block = Block::clone_from_slice(pt);
                 let mut blocks1 = ParBlock::default();
@@ -113,12 +113,12 @@ macro_rules! block_cipher_bench {
     ($cipher:path, $key_len:expr) => {
         extern crate test;
 
-        use cipher::block::{BlockCipher, BlockDecrypt, BlockEncrypt, NewBlockCipher};
+        use cipher::{BlockCipher, BlockDecrypt, BlockEncrypt, NewBlockCipher};
         use test::Bencher;
 
         #[bench]
         pub fn encrypt(bh: &mut Bencher) {
-            let state = <$cipher>::new_varkey(&[1u8; $key_len]).unwrap();
+            let state = <$cipher>::new_var(&[1u8; $key_len]).unwrap();
             let mut block = Default::default();
 
             bh.iter(|| {
@@ -130,7 +130,7 @@ macro_rules! block_cipher_bench {
 
         #[bench]
         pub fn decrypt(bh: &mut Bencher) {
-            let state = <$cipher>::new_varkey(&[1u8; $key_len]).unwrap();
+            let state = <$cipher>::new_var(&[1u8; $key_len]).unwrap();
             let mut block = Default::default();
 
             bh.iter(|| {

cipher/src/stream/dev.rs → cipher/src/dev/stream.rs

@@ -3,12 +3,12 @@
 /// Test core functionality of synchronous stream cipher
 #[macro_export]
 #[cfg_attr(docsrs, doc(cfg(feature = "dev")))]
-macro_rules! stream_cipher_sync_test {
+macro_rules! stream_cipher_test {
     ($name:ident, $cipher:ty, $test_name:expr) => {
         #[test]
         fn $name() {
             use cipher::generic_array::GenericArray;
-            use cipher::stream::{blobby::Blob4Iterator, NewStreamCipher, SyncStreamCipher};
+            use cipher::{blobby::Blob4Iterator, NewCipher, StreamCipher};
 
             let data = include_bytes!(concat!("data/", $test_name, ".blb"));
             for (i, row) in Blob4Iterator::new(data).unwrap().enumerate() {
@@ -44,7 +44,7 @@ macro_rules! stream_cipher_seek_test {
         #[test]
         fn $name() {
             use cipher::generic_array::GenericArray;
-            use cipher::stream::{NewStreamCipher, SyncStreamCipher, SyncStreamCipherSeek};
+            use cipher::{NewCipher, StreamCipher, StreamCipherSeek};
 
             fn get_cipher() -> $cipher {
                 <$cipher>::new(&Default::default(), &Default::default())
@@ -97,7 +97,7 @@ macro_rules! stream_cipher_async_test {
         #[test]
         fn $name() {
             use cipher::generic_array::GenericArray;
-            use cipher::stream::{blobby::Blob4Iterator, NewStreamCipher, StreamCipher};
+            use cipher::{blobby::Blob4Iterator, AsyncStreamCipher, NewCipher};
 
             fn run_test(
                 key: &[u8],
@@ -172,8 +172,7 @@ macro_rules! stream_cipher_sync_bench {
     ($cipher:path) => {
         extern crate test;
 
-        use cipher::generic_array::GenericArray;
-        use cipher::stream::{NewStreamCipher, SyncStreamCipher};
+        use cipher::{generic_array::GenericArray, NewCipher, StreamCipher};
         use test::Bencher;
 
         #[inline(never)]
@@ -225,8 +224,7 @@ macro_rules! stream_cipher_async_bench {
     ($cipher:path) => {
         extern crate test;
 
-        use cipher::generic_array::GenericArray;
-        use cipher::stream::{NewStreamCipher, StreamCipher};
+        use cipher::{generic_array::GenericArray, AsyncStreamCipher, NewCipher};
         use test::Bencher;
 
         #[inline(never)]

cipher/src/errors.rs

@@ -1,4 +1,4 @@
-//! Error types
+//! Error types.
 
 use core::fmt;
 

cipher/src/lib.rs

@@ -16,14 +16,15 @@
 #[cfg(feature = "std")]
 extern crate std;
 
-pub mod block;
+#[cfg(feature = "dev")]
+pub use blobby;
+
+mod block;
+mod common;
+#[cfg(feature = "dev")]
+mod dev;
 pub mod errors;
-pub mod stream;
+mod stream;
 
-pub use crate::{
-    block::{
-        BlockCipher, BlockDecrypt, BlockDecryptMut, BlockEncrypt, BlockEncryptMut, NewBlockCipher,
-    },
-    stream::{NewStreamCipher, StreamCipher, SyncStreamCipher, SyncStreamCipherSeek},
-};
+pub use crate::{block::*, common::*, stream::*};
 pub use generic_array::{self, typenum::consts};