digest: add newtype macros

digest/README.md

@@ -64,25 +64,6 @@ let hash = Sha256::digest(b"my message");
 println!("Result: {:x}", hash);
 ```
 
-### Hashing `Read`-able objects
-
-If you want to hash data from [`Read`][3] trait (e.g. from file) you can rely on
-implementation of [`Write`][4] trait (requires enabled-by-default `std` feature):
-
-```rust
-use sha2::{Sha256, Digest};
-use std::{fs, io};
-
-let mut file = fs::File::open(&path)?;
-let mut hasher = Sha256::new();
-let n = io::copy(&mut file, &mut hasher)?;
-let hash = hasher.finalize();
-
-println!("Path: {}", path);
-println!("Bytes processed: {}", n);
-println!("Hash value: {:x}", hash);
-```
-
 ### Generic code
 
 You can write generic code over `Digest` (or other traits from `digest` crate)

digest/src/core_api.rs

@@ -5,6 +5,7 @@
 //! higher-level traits.
 use crate::InvalidOutputSize;
 
+pub use block_buffer::{Eager, Lazy};
 pub use crypto_common::{AlgorithmName, Block, BlockSizeUser, OutputSizeUser, Reset};
 
 use block_buffer::{BlockBuffer, BufferKind};
@@ -15,7 +16,7 @@ mod rt_variable;
 mod wrapper;
 mod xof_reader;
 
-pub use ct_variable::CtVariableCoreWrapper;
+pub use ct_variable::CtOutWrapper;
 pub use rt_variable::RtVariableCoreWrapper;
 pub use wrapper::{CoreProxy, CoreWrapper};
 pub use xof_reader::XofReaderCoreWrapper;

digest/src/core_api/ct_variable.rs

@@ -16,10 +16,10 @@ use crypto_common::{
     hazmat::{DeserializeStateError, SerializableState, SerializedState, SubSerializedStateSize},
     typenum::{IsLess, IsLessOrEqual, Le, LeEq, NonZero, Sum, U1, U256},
 };
-/// Wrapper around [`VariableOutputCore`] which selects output size
-/// at compile time.
+
+/// Wrapper around [`VariableOutputCore`] which selects output size at compile time.
 #[derive(Clone)]
-pub struct CtVariableCoreWrapper<T, OutSize>
+pub struct CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,
@@ -29,7 +29,7 @@ where
     _out: PhantomData<OutSize>,
 }
 
-impl<T, OutSize> HashMarker for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize> HashMarker for CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore + HashMarker,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,
@@ -38,15 +38,15 @@ where
 }
 
 #[cfg(feature = "mac")]
-impl<T, OutSize> MacMarker for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize> MacMarker for CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore + MacMarker,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,
     LeEq<OutSize, T::OutputSize>: NonZero,
 {
 }
 
-impl<T, OutSize> CollisionResistance for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize> CollisionResistance for CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore + CollisionResistance,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,
@@ -55,7 +55,7 @@ where
     type CollisionResistance = T::CollisionResistance;
 }
 
-impl<T, OutSize> BlockSizeUser for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize> BlockSizeUser for CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,
@@ -64,7 +64,7 @@ where
     type BlockSize = T::BlockSize;
 }
 
-impl<T, OutSize> UpdateCore for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize> UpdateCore for CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,
@@ -76,7 +76,7 @@ where
     }
 }
 
-impl<T, OutSize> OutputSizeUser for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize> OutputSizeUser for CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,
@@ -85,7 +85,7 @@ where
     type OutputSize = OutSize;
 }
 
-impl<T, OutSize> BufferKindUser for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize> BufferKindUser for CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,
@@ -94,7 +94,7 @@ where
     type BufferKind = T::BufferKind;
 }
 
-impl<T, OutSize> FixedOutputCore for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize> FixedOutputCore for CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,
@@ -117,7 +117,7 @@ where
     }
 }
 
-impl<T, OutSize> Default for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize> Default for CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,
@@ -132,7 +132,7 @@ where
     }
 }
 
-impl<T, OutSize> CustomizedInit for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize> CustomizedInit for CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore + VarOutputCustomized,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,
@@ -147,7 +147,7 @@ where
     }
 }
 
-impl<T, OutSize> Reset for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize> Reset for CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,
@@ -159,7 +159,7 @@ where
     }
 }
 
-impl<T, OutSize> AlgorithmName for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize> AlgorithmName for CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore + AlgorithmName,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,
@@ -173,15 +173,15 @@ where
 }
 
 #[cfg(feature = "zeroize")]
-impl<T, OutSize> zeroize::ZeroizeOnDrop for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize> zeroize::ZeroizeOnDrop for CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore + zeroize::ZeroizeOnDrop,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,
     LeEq<OutSize, T::OutputSize>: NonZero,
 {
 }
 
-impl<T, OutSize> fmt::Debug for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize> fmt::Debug for CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore + AlgorithmName,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,
@@ -195,7 +195,7 @@ where
 type CtVariableCoreWrapperSerializedStateSize<T> =
     Sum<<T as SerializableState>::SerializedStateSize, U1>;
 
-impl<T, OutSize> SerializableState for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize> SerializableState for CtOutWrapper<T, OutSize>
 where
     T: VariableOutputCore + SerializableState,
     OutSize: ArraySize + IsLessOrEqual<T::OutputSize>,

digest/src/core_api/rt_variable.rs

@@ -18,8 +18,7 @@ use crypto_common::{
 #[cfg(feature = "zeroize")]
 use zeroize::ZeroizeOnDrop;
 
-/// Wrapper around [`VariableOutputCore`] which selects output size
-/// at run time.
+/// Wrapper around [`VariableOutputCore`] which selects output size at run time.
 #[derive(Clone)]
 pub struct RtVariableCoreWrapper<T: VariableOutputCore> {
     core: T,
@@ -64,11 +63,19 @@ impl<T: VariableOutputCore> BlockSizeUser for RtVariableCoreWrapper<T> {
     type BlockSize = T::BlockSize;
 }
 
-impl<T: VariableOutputCore + Reset> Reset for RtVariableCoreWrapper<T> {
+// TODO: remove because the hasher may be customized?
+impl<T: VariableOutputCore> Reset for RtVariableCoreWrapper<T> {
     #[inline]
     fn reset(&mut self) {
         self.buffer.reset();
-        self.core.reset();
+        self.core = T::new(self.output_size as usize).unwrap();
+    }
+}
+
+impl<T: VariableOutputCore + AlgorithmName> AlgorithmName for RtVariableCoreWrapper<T> {
+    fn write_alg_name(f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        T::write_alg_name(f)?;
+        f.write_str("Var")
     }
 }
 

digest/src/core_api/wrapper.rs

@@ -149,6 +149,13 @@ impl<T: ExtendableOutputCore + Reset> ExtendableOutputReset for CoreWrapper<T> {
     }
 }
 
+impl<T: BufferKindUser + AlgorithmName> AlgorithmName for CoreWrapper<T> {
+    #[inline]
+    fn write_alg_name(f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
+        T::write_alg_name(f)
+    }
+}
+
 impl<T: BufferKindUser> Drop for CoreWrapper<T> {
     #[inline]
     fn drop(&mut self) {
@@ -214,20 +221,12 @@ where
     }
 }
 
-/// A proxy trait to a core type implemented by [`CoreWrapper`]
-// TODO: replace with an inherent associated type on stabilization:
-// https://github.com/rust-lang/rust/issues/8995
-pub trait CoreProxy: sealed::Sealed {
+/// A proxy trait to a core type.
+pub trait CoreProxy {
     /// Type wrapped by [`CoreWrapper`].
     type Core;
 }
 
-mod sealed {
-    pub trait Sealed {}
-}
-
-impl<T: BufferKindUser> sealed::Sealed for CoreWrapper<T> {}
-
 impl<T: BufferKindUser> CoreProxy for CoreWrapper<T> {
     type Core = T;
 }

digest/src/lib.rs

@@ -55,6 +55,7 @@ pub mod core_api;
 mod digest;
 #[cfg(feature = "mac")]
 mod mac;
+mod newtype;
 mod xof_fixed;
 
 #[cfg(feature = "core-api")]

digest/src/newtype.rs

@@ -0,0 +1,4 @@
+mod fixed;
+mod variable_ct;
+mod variable_rt;
+mod xof;