feat(factory): add cipher/algorithm helper functions

des/src/des.rs

@@ -32,13 +32,17 @@ impl Des {
         let subkeys = Subkeys::from_key(&key.into());
         Self { subkeys }
     }
+
+    #[inline]
+    #[must_use]
+    pub fn from_key(key: impl Into<Key>) -> Self {
+        Self::new(key)
+    }
 }
 
 impl BlockCipher for Des {
-    const BLOCK_SIZE: usize = 8;
-
-    fn from_key(key: &[u8]) -> Self {
-        Self::new(key)
+    fn block_size(&self) -> usize {
+        8
     }
 
     fn transform_impl(
@@ -46,9 +50,10 @@ impl BlockCipher for Des {
         block: &[u8],
         action: cipher_core::CipherAction,
     ) -> cipher_core::CipherResult<cipher_core::Output> {
-        let block_arr: [u8; Self::BLOCK_SIZE] = block
+        let block_size = self.block_size();
+        let block_arr: [u8; 8] = block
             .try_into()
-            .map_err(|_| CipherError::invalid_block_size(Self::BLOCK_SIZE, block.len()))?;
+            .map_err(|_| CipherError::invalid_block_size(block_size, block.len()))?;
         let block64 = Block64::from_be_bytes(block_arr);
         let permutated_block = ip(block64);
 

des/src/key/des_key.rs

@@ -1,6 +1,8 @@
 use std::fmt::Debug;
 use zeroize::ZeroizeOnDrop;
 
+use crate::Block64;
+
 /// 64-bit Key for DES
 #[derive(ZeroizeOnDrop)]
 pub struct Key([u8; 8]);
@@ -36,13 +38,19 @@ impl From<&[u8]> for Key {
         let mut bytes = [0; 8];
         let len = value.len().min(8);
         bytes[..len].copy_from_slice(&value[..len]);
-        Self(bytes)
+        bytes.into()
     }
 }
 
 impl From<u64> for Key {
     fn from(key: u64) -> Self {
-        Self(key.to_be_bytes())
+        key.to_be_bytes().into()
+    }
+}
+
+impl From<Block64> for Key {
+    fn from(key: Block64) -> Self {
+        key.to_be_bytes().into()
     }
 }