feat/lamport plus

.github/workflows/rust.yml

@@ -11,14 +11,14 @@ env:
 
 jobs:
   msrv:
-    name: Verify MSRV (1.95)
+    name: Verify MSRV (1.96)
     runs-on: ubuntu-latest
 
     steps:
       - uses: actions/checkout@v4
 
-      - name: Install Rust Toolchain (1.95)
-        uses: dtolnay/rust-toolchain@1.95.0
+      - name: Install Rust Toolchain (1.96)
+        uses: dtolnay/rust-toolchain@1.96.0
 
       - name: Check
         run: cargo check --all-features

CHANGELOG.md

@@ -5,6 +5,28 @@ 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).
 
+## [1.2.0] - 2026-09-01
+
+### Added
+
+- Merkle-tree Lamport multikey view (`views::lamport_merkle`, behind the default `lamport` feature) wrapping the `lamport_signature_plus` 0.5.0 `Mt*` API. Supports 11 digest variants (SHA3-512/384/256, SHA2-512/384/256, BLAKE2b-512, BLAKE2s-256, BLAKE3-256, SHAKE-128/256) with 55 new codecs (`LamportMerkle*Pub/Priv/PrivShare`, codes `0x1a64`-`0x1a8e`).
+- Depth attribute (`AttrId::Depth`, code 29) stamped on every merkle artifact and strictly cross-checked against the depth byte embedded in the `Mt*` wire data; mismatches return `AttributesError::DepthMismatch`.
+- `MerkleStateView` trait and `Views::merkle_state_view()`: `depth`, `capacity`, `next_index`, and `remaining_signatures` introspection parsed from the tree state.
+- `Builder::new_from_random_bytes_with_depth(codec, depth, rng)` (depth 1..=3 validated and stamped) and `Builder::with_depth(depth)`.
+- `LAMPORT_MERKLE_KEY_CODECS` and `LAMPORT_MERKLE_KEY_SHARE_CODECS` codec lists; the 11 `LamportMerkle*PrivShare` codecs added to `KEY_SHARE_CODECS`.
+- Threshold support mirroring the one-time Lamport view: `split(t, n)` produces `LamportMerkle*PrivShare` multikeys (GF(256) shares of the whole tree state); share signing produces `LamportMerkle*SigShare` multisigs; accumulation/combination happens in multi-sig. Keys are never reconstructed.
+- `sign_advance` method on the `SignView` trait. Stateful signature schemes (XMSS, merkle-tree Lamport) override it to return the `Multisig` AND the advanced `Multikey` (codec, comment, and attributes preserved; only `KeyData` replaced). The caller must persist the advanced key so the consumed one-time slot is never reused. The default implementation returns `UnsupportedAlgorithm`, so stateless schemes and existing external trait impls stay source-compatible.
+- `AttrId::Depth` attribute (code 29, name `depth`, one raw byte) for merkle-tree signature schemes.
+- `AttributesError::DepthMismatch { expected, found }` error variant.
+
+### Changed
+
+- **Breaking:** removed the free function `multi_key::views::xmss::sign_advance`. Use the `SignView::sign_advance` trait method instead. The trait method returns the advanced key as a full `Multikey` rather than raw secret-key bytes.
+- Bumped `lamport_signature_plus` from `0.5.0-rc2` to `0.5.0` (adds the merkle-tree API used by the next release).
+- Raised `rust-version` from `1.95` to `1.96` (required by `lamport_signature_plus` 0.5.0).
+- `Builder::with_key_bytes` now accepts unsized byte slices (`&(impl AsRef<[u8]> + ?Sized)`).
+- `multi-sig` dependency raised to `1.3` (adds `AttrId::Depth`, `Builder::with_depth`, and `Multisig::depth()`).
+
 ## [1.1.1] - 2026-08-18
 
 ### Fixed

Cargo.toml

@@ -1,8 +1,8 @@
 [package]
 name = "multi-key"
-version = "1.1.1"
+version = "1.2.0"
 edition = "2024"
-rust-version = "1.95"
+rust-version = "1.96"
 authors = ["Dave Grantham <dwg@linuxprogrammer.org>"]
 description = "Multikey self-describing cryptographic key data"
 repository = "https://github.com/cryptidtech/multi-key.git"
@@ -47,7 +47,7 @@ mceliece348864 = { version = "1.0" }
 ml-dsa = "0.1.1"
 ml-kem = "0.3"
 multi-base = { version = "1.0", default-features = false }
-multi-codec = "1.2"
+multi-codec = "1.3"
 multi-hash = "1.1"
 multi-sig = "1.2"
 multi-trait = { version = "1.0", default-features = false }
@@ -77,13 +77,19 @@ vsss-rs = "6.0"
 x25519-dalek = { version = "3.0", features = ["static_secrets", "getrandom"] }
 zeroize = "1"
 # Lamport support (feature-gated, default-enabled)
-lamport_signature_plus = { version = "0.5.0-rc2", optional = true }
+lamport_signature_plus = { version = "0.5.0", optional = true }
 sha3 = { version = "0.12", optional = true }
 blake2 = { version = "0.11.0-rc.6", optional = true }
 shake = { version = "0.1", optional = true }
 # XMSS support (feature-gated, default-enabled)
 xmss = { version = "0.1.0-pre.0", optional = true }
 
+# Local multi-codec 1.3.0 and multi-sig with `AttrId::Depth` until published
+# (remove at release).
+[patch.crates-io]
+multi-codec = { path = "../multi-codec" }
+multi-sig = { path = "../multi-sig" }
+
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 blsful = { version = "4.0.0", default-features = false, features = ["rust"] }
 getrandom_02 = { package = "getrandom", version = "0.2", features = ["js"] }

src/attrid.rs

@@ -82,6 +82,10 @@ pub enum AttrId {
     AlgorithmName,
     /// An arbitrary key type for non-standard keys (optional)
     KeyType,
+    /// Merkle-tree signature scheme depth (one raw byte; the tree holds
+    /// 2^depth one-time leaves). Cross-checked against the depth byte embedded
+    /// in the key/signature wire data.
+    Depth,
 }
 
 impl AttrId {
@@ -122,6 +126,7 @@ impl AttrId {
             AttrId::ThresholdMetaCipher => "threshold-meta-cipher",
             AttrId::AlgorithmName => "algorithm-name",
             AttrId::KeyType => "key-type",
+            AttrId::Depth => "depth",
         }
     }
 }
@@ -166,6 +171,7 @@ impl TryFrom<u8> for AttrId {
             26 => Ok(AttrId::ThresholdMetaCipher),
             27 => Ok(AttrId::AlgorithmName),
             28 => Ok(AttrId::KeyType),
+            29 => Ok(AttrId::Depth),
             _ => Err(AttributesError::InvalidAttributeValue(c).into()),
         }
     }
@@ -230,6 +236,7 @@ impl TryFrom<&str> for AttrId {
             "threshold-meta-cipher" => Ok(AttrId::ThresholdMetaCipher),
             "algorithm-name" => Ok(AttrId::AlgorithmName),
             "key-type" => Ok(AttrId::KeyType),
+            "depth" => Ok(AttrId::Depth),
             _ => Err(AttributesError::InvalidAttributeName(s.to_string()).into()),
         }
     }

src/error.rs

@@ -138,6 +138,15 @@ pub enum AttributesError {
     /// The threshold marker signature failed verification (tampered marker).
     #[error("Threshold marker signature verification failed")]
     ThresholdMarkerSigInvalid,
+    /// A merkle-tree depth attribute does not match the depth byte embedded in
+    /// the key or signature wire data.
+    #[error("Depth mismatch: attribute says {expected}, wire data says {found}")]
+    DepthMismatch {
+        /// depth declared by the `depth` attribute
+        expected: u8,
+        /// depth byte embedded in the wire data
+        found: u8,
+    },
 }
 
 /// Conversions errors created by this library

src/lib.rs

@@ -141,8 +141,8 @@ pub use views::threshold_meta::{
 };
 pub use views::{
     AttrView, CipherAttrView, CipherView, ConvView, DataView, FingerprintView, KdfAttrView,
-    KdfView, OpenView, SealView, SignView, ThresholdAttrView, ThresholdDisclosureView,
-    ThresholdKeyView, ThresholdView, VerifyView, Views,
+    KdfView, MerkleStateView, OpenView, SealView, SignView, ThresholdAttrView,
+    ThresholdDisclosureView, ThresholdKeyView, ThresholdView, VerifyView, Views,
 };
 
 /// Key splitting / recombination (verifiable threshold shares)
@@ -155,6 +155,8 @@ pub use mk::{
     MAX_DECODED_SIZE, ML_DSA_KEY_CODECS, ML_KEM_KEY_CODECS, Multikey, SLH_DSA_KEY_CODECS,
     X25519_KEY_CODECS,
 };
+#[cfg(feature = "lamport")]
+pub use mk::{LAMPORT_MERKLE_KEY_CODECS, LAMPORT_MERKLE_KEY_SHARE_CODECS};
 
 /// Nonce type
 pub mod nonce;