Crate ledvar_core 

ledvar-core — the reference implementation of the Ledvar protocol core: the data model, the canonical content-addressed hashing, and well-formedness.

The crate is deliberately domain-blind (it knows nothing about security, cloud, or any domain) and dependency-light (serde for the wire model, sha2 for hashing — nothing else). Hashing streams the canonical bytes straight into SHA-256 with no intermediate allocation; see the design note in docs/canonical-hashing.md.

use ledvar_core::Node;
use std::collections::{BTreeMap, BTreeSet};

let mut content = BTreeMap::new();
content.insert("grants".to_string(), BTreeSet::from(["SELECT".into(), "INSERT".into()]));
content.insert("risk".to_string(), BTreeSet::from(["Medium".into()]));
let node = Node {
    path: vec!["mydb".into(), "user:app".into()],
    content,
    labels: BTreeMap::new(),
    refs: Vec::new(),
};
assert_eq!(node.identity_key().unwrap(), "8e303e0e8139ff7d377e0eaf9097e2790071f9914bc7cf8b28020bb98a3cca95");
assert_eq!(node.content_hash().unwrap(), "296190489d577d410f0f7fa09dfa24660722227fe405daaf621f4e2666bf370f");

Structs

Node

A node of the tree: identity (path) + content (attributes). The collector fills it; this crate computes the hashes (SPEC §4.2, §5).

Ref

A directed annotation edge from one node to another (SPEC §4.3).

Snapshot

One observation of some state at a point in time (SPEC §4.1).

Enums

Error

Why a snapshot is not well-formed, or a version cannot be parsed.

Constants

SUPPORTED_PROTOCOL_MAJOR

Protocol MAJOR this implementation understands. Snapshots with a different MAJOR are rejected by crate::validate.

SUPPORTED_PROTOCOL_MINOR

Protocol MINOR this implementation targets. While MAJOR is 0 the exact MINOR is contract-significant — a MINOR bump within 0.x may move the canonical form (SPEC §10) — so crate::validate rejects a snapshot whose MINOR differs while MAJOR is 0.

Functions

canonical_json_string

Canonical JSON encoding of ONE string value (SPEC §6.1), quotes included: minimal RFC 8259 escaping, lowercase \uXXXX, no Unicode normalization — the exact same routine the protocol hashes run through. Exposed so higher layers (e.g. an ecosystem convention that canonicalises the non-hashed labels/refs fields) can produce byte-identical encodings without re-implementing the escaping rules.

parse

Parse a MAJOR.MINOR.PATCH string into its three numeric components.

parse_major

Parse just the MAJOR (only MAJOR is contract-significant from MAJOR ≥ 1). Thin wrapper over parse; the full grammar (including MINOR/PATCH and no-leading-zeros) is still enforced.

validate

Validate that a snapshot is well-formed (SPEC §9): supported version, every node well-formed (see validate_node), and all paths unique within the snapshot.

validate_node

Well-formedness of a single node (SPEC §9), independent of any snapshot: a non-empty path with no empty segment, no empty attribute name, and no empty value set. index is used only for error reporting (pass 0 for a bare node). Called by validate per node, and by Node::identity_key / Node::content_hash themselves, so an ill-formed node is never hashed no matter how the caller reaches the hash (SPEC §9: an implementation MUST NOT hash an ill-formed Snapshot).