add Debug and Error impls for block-modes error types. fixes #44

block-modes/Cargo.toml

@@ -1,8 +1,8 @@
 [package]
 name = "block-modes"
-version = "0.3.1"
+version = "0.3.2"
 authors = ["RustCrypto Developers"]
-license = "MIT/Apache-2.0"
+license = "MIT OR Apache-2.0"
 description = "Block cipher modes of operation"
 documentation = "https://docs.rs/block-modes"
 repository = "https://github.com/RustCrypto/block-ciphers"

block-modes/src/ecb.rs

@@ -1,7 +1,8 @@
 use block_cipher_trait::BlockCipher;
 use block_cipher_trait::generic_array::typenum::Unsigned;
 use block_padding::Padding;
-use traits::{BlockMode, InvalidKeyIvLength};
+use traits::BlockMode;
+use errors::InvalidKeyIvLength;
 use utils::{Block, get_par_blocks};
 use core::marker::PhantomData;
 

block-modes/src/errors.rs

@@ -0,0 +1,37 @@
+use core::fmt;
+#[cfg(feature = "std")]
+use std::error;
+
+/// Block mode error.
+#[derive(Clone, Copy, Debug)]
+pub struct BlockModeError;
+
+/// Invalid key or IV length error.
+#[derive(Clone, Copy, Debug)]
+pub struct InvalidKeyIvLength;
+
+impl fmt::Display for BlockModeError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        f.write_str("BlockModeError")
+    }
+}
+
+#[cfg(feature = "std")]
+impl error::Error for BlockModeError {
+    fn description(&self) -> &str {
+        "block mode error"
+    }
+}
+
+impl fmt::Display for InvalidKeyIvLength {
+    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        f.write_str("InvalidKeyIvLength")
+    }
+}
+
+#[cfg(feature = "std")]
+impl error::Error for InvalidKeyIvLength {
+    fn description(&self) -> &str {
+        "invalid key or IV length during block cipher mode initialization"
+    }
+}

block-modes/src/lib.rs

@@ -82,7 +82,9 @@ extern crate std;
 
 mod utils;
 mod traits;
-pub use traits::{BlockMode, BlockModeError, InvalidKeyIvLength};
+mod errors;
+pub use traits::BlockMode;
+pub use errors::{BlockModeError, InvalidKeyIvLength};
 
 mod cbc;
 pub use cbc::Cbc;

block-modes/src/traits.rs

@@ -6,14 +6,7 @@ use block_cipher_trait::generic_array::GenericArray;
 use block_cipher_trait::generic_array::typenum::Unsigned;
 use block_padding::Padding;
 use utils::{Block, Key, to_blocks};
-
-/// Block mode error.
-#[derive(Clone, Copy, Debug)]
-pub struct BlockModeError;
-
-/// Invalid key or IV length error.
-#[derive(Clone, Copy, Debug)]
-pub struct InvalidKeyIvLength;
+use errors::{InvalidKeyIvLength, BlockModeError};
 
 /// Trait for a block cipher mode of operation that is used to apply a block cipher
 /// operation to input data to transform it into a variable-length output message.