fix/fips xof

.github/workflows/rust.yml

@@ -34,14 +34,14 @@ jobs:
         run: cargo test --verbose --all-features
 
   msrv:
-    name: Verify MSRV (1.85)
+    name: Verify MSRV (1.99)
     runs-on: ubuntu-latest
 
     steps:
       - uses: actions/checkout@v4
 
-      - name: Install Rust Toolchain (1.85)
-        uses: dtolnay/rust-toolchain@1.85.0
+      - name: Install Rust Toolchain (1.99)
+        uses: dtolnay/rust-toolchain@1.99.0
 
       - name: Check
         run: cargo check --all-features

.gitignore

@@ -17,3 +17,6 @@ Cargo.lock
 # Added by cargo
 
 /target
+
+plan.md
+session.json

CHANGELOG.md

@@ -5,6 +5,33 @@ All notable changes to this project are documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [2.0.0] - 2026-10-07
+
+### Added
+
+- SHAKE128 and SHAKE256 extendable-output function (XOF) support. `Codec::Shake128` and `Codec::Shake256` now end the `HASH_CODECS` list.
+- Streaming `Builder` support. `Builder::update` feeds data in chunks, and `Builder::output_len` sets the XOF output length in bytes.
+- The `MAX_HASH_LENGTH` constant. The builder rejects XOF output lengths above this 16 MiB value before any allocation or squeeze.
+- The `fips` feature. It exports the `FIPS_CODECS` and `SAFE_FIPS_CODECS` constants, which list the NIST FIPS approved hash algorithms.
+- New error variants `Error::OutputLenRequired { codec }` and `Error::OutputLenInvalid { codec, output_len, max }`. They report a missing or out-of-range XOF output length.
+
+### Changed
+
+- `Builder::new(codec)` now returns a `Result`. It returns `Error::UnsupportedHash` for a codec outside `HASH_CODECS`.
+- Removed `Builder::new_from_bytes`. Use `Builder::new` and `Builder::update` instead.
+- `Builder::try_build()` and `Builder::try_build_encoded()` now consume the builder. Clone the builder when you need a second build.
+- `Builder::try_build()` now checks the digest length against the codec's output policy. Fixed-output codecs accept only their exact policy length, and the XOF codecs accept 1 to `MAX_HASH_LENGTH` bytes.
+- Removed the derived `Default` implementation for `Builder`. Create a builder with `Builder::new(codec)`.
+- Fixed-output codecs ignore a `Builder::output_len` setting. They always produce their exact policy digest length.
+- `HASH_CODECS` grew to 25 entries, and `SAFE_HASH_CODECS` grew to 10 entries.
+- Streamed `Blake3` builds now require an `output_len` setting. A `Blake3` digest set with `with_hash` accepts 1 to `MAX_HASH_LENGTH` bytes.
+- Raised the MSRV from 1.85 to 1.99. The CI MSRV job now checks 1.99.0.
+- Made the `HashDigest::len` and `HashDigest::is_empty` methods `const`.
+
+### Dependencies
+
+- Added the `shake = "0.1"` dependency. It provides the SHAKE128 and SHAKE256 extendable-output functions.
+
 ## [1.1.2] - 2026-08-17
 
 ### Fixed
@@ -138,6 +165,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - Added a test suite for edge cases, integration, proptests, and security.
 - Initial published release on crates.io as `multi-hash`.
 
+[2.0.0]: https://github.com/cryptidtech/multi-hash/compare/v1.1.2...v2.0.0
 [1.1.2]: https://github.com/cryptidtech/multi-hash/compare/v1.1.1...v1.1.2
 [1.1.1]: https://github.com/cryptidtech/multi-hash/compare/v1.1.0...v1.1.1
 [1.1.0]: https://github.com/cryptidtech/multi-hash/compare/v1.0.7...v1.1.0

Cargo.toml

@@ -1,8 +1,8 @@
 [package]
 name = "multi-hash"
-version = "1.1.2"
+version = "2.0.0"
 edition = "2024"
-rust-version = "1.85"
+rust-version = "1.99"
 authors = ["Dave Grantham <dwg@linuxprogrammer.org>"]
 description = "Multihash self-describing cryptographic hash data"
 repository = "https://github.com/cryptidtech/multi-hash.git"
@@ -14,21 +14,25 @@ categories = ["cryptography", "encoding"]
 [features]
 default = ["serde"]
 
+# expose the FIPS approved codec constants, FIPS_CODECS and SAFE_FIPS_CODECS
+fips = []
+
 [dependencies]
 blake2 = "0.11.0-rc.6"
 blake3 = { version = "1.8", features = ["traits-preview", "zeroize"] }
 multi-base = "1.0"
 multi-codec = "1.2"
 multi-trait = "1.0"
 multi-util = "1.1"
-digest = "0.11"
+digest = { version = "0.11", features = ["alloc"] }
 hex = "0.4"
 md-5 = "0.11"
 ripemd = "0.2"
 serde = { version = "1.0", default-features = false, features = ["alloc", "derive"], optional = true }
 sha1 = "0.11"
 sha2 = "0.11"
 sha3 = "0.12"
+shake = "0.1"
 subtle = "2"
 thiserror = { version = "2.0" }
 typenum = "1.20"