hmac: move EagerHash to the crate root (#189)

The trait was unintentionally moved to the `block_api` module. Since
it's used in generic code with non-block `Hmac` and `HmacReset` types,
it's worth to expose it in the crate root.

Author: newpavlov

hmac/src/block_api.rs

@@ -1,41 +1,15 @@
-use crate::utils::{IPAD, OPAD, get_der_key};
+use crate::utils::{EagerHash, IPAD, OPAD, get_der_key};
 use core::{fmt, slice};
 use digest::{
-    Digest, HashMarker, InvalidLength, KeyInit, MacMarker, Output, Reset,
+    InvalidLength, KeyInit, MacMarker, Output, Reset,
     block_api::{
-        AlgorithmName, Block, BlockSizeUser, Buffer, BufferKindUser, CoreProxy, FixedOutputCore,
+        AlgorithmName, Block, BlockSizeUser, Buffer, BufferKindUser, FixedOutputCore,
         OutputSizeUser, UpdateCore,
     },
     block_buffer::Eager,
     crypto_common::{Key, KeySizeUser},
 };
 
-/// Trait implemented by eager hashes which expose their block-level core.
-pub trait EagerHash: BlockSizeUser + Digest {
-    /// Block-level core type of the hash.
-    type Core: HashMarker
-        + UpdateCore
-        + FixedOutputCore
-        + BlockSizeUser<BlockSize = <Self as BlockSizeUser>::BlockSize>
-        + BufferKindUser<BufferKind = Eager>
-        + Default
-        + Clone;
-}
-
-impl<T> EagerHash for T
-where
-    T: CoreProxy + BlockSizeUser + Digest,
-    <T as CoreProxy>::Core: HashMarker
-        + UpdateCore
-        + FixedOutputCore
-        + BlockSizeUser<BlockSize = <Self as BlockSizeUser>::BlockSize>
-        + BufferKindUser<BufferKind = Eager>
-        + Default
-        + Clone,
-{
-    type Core = T::Core;
-}
-
 /// Generic core HMAC instance, which operates over blocks.
 pub struct HmacCore<D: EagerHash> {
     digest: D::Core,

hmac/src/lib.rs

@@ -106,8 +106,8 @@ mod utils;
 
 pub use simple::SimpleHmac;
 pub use simple_reset::SimpleHmacReset;
+pub use utils::EagerHash;
 
-use block_api::EagerHash;
 use core::fmt;
 use digest::block_api::{AlgorithmName, CoreProxy};
 

hmac/src/utils.rs

@@ -1,6 +1,8 @@
 use digest::{
-    Digest,
-    block_api::{Block, BlockSizeUser},
+    Digest, HashMarker,
+    block_api::{
+        Block, BlockSizeUser, BufferKindUser, CoreProxy, Eager, FixedOutputCore, UpdateCore,
+    },
 };
 
 pub(crate) const IPAD: u8 = 0x36;
@@ -30,3 +32,29 @@ pub(crate) fn get_der_key<D: Digest + BlockSizeUser>(key: &[u8]) -> Block<D> {
     }
     der_key
 }
+
+/// Trait implemented by eager hashes which expose their block-level core.
+pub trait EagerHash: BlockSizeUser + Digest {
+    /// Block-level core type of the hash.
+    type Core: HashMarker
+        + UpdateCore
+        + FixedOutputCore
+        + BlockSizeUser<BlockSize = <Self as BlockSizeUser>::BlockSize>
+        + BufferKindUser<BufferKind = Eager>
+        + Default
+        + Clone;
+}
+
+impl<T> EagerHash for T
+where
+    T: CoreProxy + BlockSizeUser + Digest,
+    <T as CoreProxy>::Core: HashMarker
+        + UpdateCore
+        + FixedOutputCore
+        + BlockSizeUser<BlockSize = <Self as BlockSizeUser>::BlockSize>
+        + BufferKindUser<BufferKind = Eager>
+        + Default
+        + Clone,
+{
+    type Core = T::Core;
+}