Fast SHA-224, SHA-256, SHA-384 and SHA-512 hashing for Elm Bytes.

A drop-in replacement for folkertdev/elm-sha2, with a faster implementation.

import SHA256

SHA256.fromString "hello world"        -- Digest
SHA256.fromBytes bytes                 -- Digest
SHA256.fromByteValues [0x68, 0x69]     -- Digest

SHA256.toHex digest                    -- String
SHA256.toBase64 digest                 -- String
SHA256.toBytes digest                  -- Bytes
SHA256.toByteValues digest             -- List Int

The same API is exposed by SHA224, SHA384 and SHA512.

See the module docs for the full API.

elm install elm-cardano/sha2

Performance is a first-class concern for this package. The 64 SHA-256 rounds (and 80 SHA-512 rounds) are fully unrolled, with round constants inlined as integer literals and all intermediate state held in flat Int let-bindings. Block decoding uses map5/map2 shapes that hit V8's fast paths for Decode.map.

Benchmarked against the reference folkertdev/elm-sha2 package:

SHA-256 is ~2.1x faster and SHA-512 is ~4x faster.

See bench/ for the full benchmarking setup. See bench/REPORT.md for the history of attempted optimizations.

pnpm install
pnpm test           # run tests
pnpm review         # elm-review
pnpm format:check   # check formatting
pnpm bench:build    # build benchmarks
pnpm bench:test     # run benchmark correctness checks