Crate ethereum_hashing

Optimized SHA256 for use in Ethereum.

The initial purpose of this crate was to provide an abstraction over the hash function used in the beacon chain. The hash function changed during the specification process, so defining it once in this crate made it easy to replace.

Now this crate serves primarily as a wrapper over two SHA256 crates: sha2 and ring – which it switches between at runtime based on the availability of SHA intrinsics.

Re-exports

• pub use self::DynamicContext as Context;

Structs

• RingImpl
  Implementation of SHA256 using the ring crate (fastest on CPUs without SHA extensions).
• ZERO_HASHES
  Cached zero hashes where ZERO_HASHES[i] is the hash of a Merkle tree with 2^i zero leaves.

Enums

• DynamicContext
  Context encapsulating all implemenation contexts.
• DynamicImpl
  Default dynamic implementation that switches between available implementations.

Constants

• HASH_LEN
  Length of a SHA256 hash in bytes.
• ZERO_HASHES_MAX_INDEX
  The max index that can be used with ZERO_HASHES.

Traits

• Sha256
  Top-level trait implemented by both sha2 and ring implementations.
• Sha256Context
  Context trait for abstracting over implementation contexts.

Functions

• hash
  Returns the digest of input using the best available implementation.
• hash32_concat
  Compute the hash of two slices concatenated.
• hash_fixed
  Hash function returning a fixed-size array (to save on allocations).
• have_sha_extensions