implement StreamCipher::new_var via BlockCipher::new_varkey

Author: newpavlov

cfb-mode/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cfb-mode"
-version = "0.3.1"
+version = "0.3.2"
 authors = ["RustCrypto Developers"]
 license = "MIT OR Apache-2.0"
 description = "Generic Cipher Feedback (CFB) mode implementation."

cfb-mode/src/lib.rs

@@ -51,7 +51,7 @@
 pub extern crate stream_cipher;
 extern crate block_cipher_trait;
 
-use stream_cipher::{StreamCipher, NewStreamCipher};
+use stream_cipher::{StreamCipher, NewStreamCipher, InvalidKeyNonceLength};
 use block_cipher_trait::BlockCipher;
 use block_cipher_trait::generic_array::GenericArray;
 use block_cipher_trait::generic_array::typenum::Unsigned;
@@ -78,6 +78,17 @@ impl<C: BlockCipher> NewStreamCipher for Cfb<C> {
         cipher.encrypt_block(&mut iv);
         Self { cipher, iv, pos: 0 }
     }
+
+    fn new_var(key: &[u8], iv: &[u8] ) -> Result<Self, InvalidKeyNonceLength> {
+        if Self::NonceSize::to_usize() != iv.len() {
+            Err(InvalidKeyNonceLength)
+        } else {
+            let cipher = C::new_varkey(key).map_err(|_| InvalidKeyNonceLength)?;
+            let mut iv = GenericArray::clone_from_slice(iv);
+            cipher.encrypt_block(&mut iv);
+            Ok(Self { cipher, iv, pos: 0 })
+        }
+    }
 }
 
 impl<C: BlockCipher> StreamCipher for Cfb<C> {

cfb8/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cfb8"
-version = "0.3.1"
+version = "0.3.2"
 authors = ["RustCrypto Developers"]
 license = "MIT OR Apache-2.0"
 description = "Generic 8-bit Cipher Feedback (CFB8) mode implementation."

cfb8/src/lib.rs

@@ -51,9 +51,10 @@
 extern crate block_cipher_trait;
 pub extern crate stream_cipher;
 
-use stream_cipher::{NewStreamCipher, StreamCipher};
+use stream_cipher::{NewStreamCipher, StreamCipher, InvalidKeyNonceLength};
 use block_cipher_trait::BlockCipher;
 use block_cipher_trait::generic_array::GenericArray;
+use block_cipher_trait::generic_array::typenum::Unsigned;
 
 /// CFB self-synchronizing stream cipher instance.
 pub struct Cfb8<C: BlockCipher> {
@@ -71,6 +72,16 @@ impl<C: BlockCipher> NewStreamCipher for Cfb8<C> {
     ) -> Self {
         Self { cipher: C::new(key), iv: iv.clone() }
     }
+
+    fn new_var(key: &[u8], iv: &[u8] ) -> Result<Self, InvalidKeyNonceLength> {
+        if Self::NonceSize::to_usize() != iv.len() {
+            Err(InvalidKeyNonceLength)
+        } else {
+            let iv = GenericArray::clone_from_slice(iv);
+            let cipher = C::new_varkey(key).map_err(|_| InvalidKeyNonceLength)?;
+            Ok(Self { cipher, iv })
+        }
+    }
 }
 
 impl<C: BlockCipher> StreamCipher for Cfb8<C> {

ctr/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ctr"
-version = "0.3.1"
+version = "0.3.2"
 authors = ["RustCrypto Developers"]
 license = "MIT OR Apache-2.0"
 description = "CTR block mode of operation"

ctr/src/lib.rs

@@ -42,7 +42,8 @@ pub extern crate stream_cipher;
 extern crate block_cipher_trait;
 
 use stream_cipher::{
-    SyncStreamCipher, SyncStreamCipherSeek, NewStreamCipher, LoopError
+    SyncStreamCipher, SyncStreamCipherSeek, NewStreamCipher,
+    LoopError, InvalidKeyNonceLength
 };
 
 use block_cipher_trait::generic_array::{ArrayLength, GenericArray};
@@ -128,6 +129,16 @@ impl<C> NewStreamCipher for Ctr128<C>
         let cipher = C::new(key);
         Self::from_cipher(cipher, nonce)
     }
+
+    fn new_var(key: &[u8], nonce: &[u8] ) -> Result<Self, InvalidKeyNonceLength> {
+        let nonce = if Self::NonceSize::to_usize() != nonce.len() {
+            Err(InvalidKeyNonceLength)?
+        } else {
+            GenericArray::from_slice(nonce)
+        };
+        let cipher = C::new_varkey(key).map_err(|_| InvalidKeyNonceLength)?;
+        Ok(Self::from_cipher(cipher, nonce))
+    }
 }
 
 impl<C> SyncStreamCipher for Ctr128<C>

ofb/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ofb"
-version = "0.1.0"
+version = "0.1.1"
 authors = ["RustCrypto Developers"]
 license = "MIT OR Apache-2.0"
 description = "Generic Output Feedback (OFB) mode implementation."

ofb/src/lib.rs

@@ -53,7 +53,9 @@
 pub extern crate stream_cipher;
 extern crate block_cipher_trait;
 
-use stream_cipher::{SyncStreamCipher, NewStreamCipher, LoopError};
+use stream_cipher::{
+    SyncStreamCipher, NewStreamCipher, LoopError, InvalidKeyNonceLength,
+};
 use block_cipher_trait::BlockCipher;
 use block_cipher_trait::generic_array::GenericArray;
 use block_cipher_trait::generic_array::typenum::Unsigned;
@@ -77,6 +79,17 @@ impl<C: BlockCipher> NewStreamCipher for Ofb<C> {
         cipher.encrypt_block(&mut block);
         Self { cipher, block, pos: 0 }
     }
+
+    fn new_var(key: &[u8], iv: &[u8] ) -> Result<Self, InvalidKeyNonceLength> {
+        if Self::NonceSize::to_usize() != iv.len() {
+            Err(InvalidKeyNonceLength)
+        } else {
+            let cipher = C::new_varkey(key).map_err(|_| InvalidKeyNonceLength)?;
+            let mut block = GenericArray::clone_from_slice(iv);
+            cipher.encrypt_block(&mut block);
+            Ok(Self { cipher, block, pos: 0 })
+        }
+    }
 }
 
 impl<C: BlockCipher> SyncStreamCipher for Ofb<C> {