Rust implementation of the did:key method

did:key Method Spec

This crate is intended to provide basic support for did:key methods. It has no external dependencies and can be compiled for any target. It was originally designed for use with DIDComm Extension for gRPC, but we recognized it may be useful if this was an independent library.

History and Governance

Originally donated to DIF by Trinsic. Ongoing management and governance done through the Identifier and Discovery WG.

Supported Key Types

• Ed25519
• X25519
• P256
• SECP256K1
• BLS12381G1/G2

Usage

Install from crates.io

did-key = "*"

To resolve a did formatted URI:

use did_key::*;

let key = resolve("did:key:z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL").unwrap();
let did_doc = key.get_did_document(Config::default());

Generate new key:

let key = generate::<Ed25519KeyPair>(None);

println!("{}", key.fingerprint());

Sign and verify:

let key = generate::<P256KeyPair>(None);
let message = b"message to be signed";

let signature = key.sign(Payload::Buffer(message.to_vec()));
let valid = key.verify(Payload::Buffer(message.to_vec()), &signature);

assert!(valid);

Create DID Document

let key = generate::<Ed25519KeyPair>(None);
let did_doc = key.get_did_document(Config::default());

let doc_json = serde_json::to_string_pretty(&did_doc).unwrap();

The default json format for key data is JSON-LD. To serialize a document using JOSE key format (using JWK), configure the input parameter or use one of the static configurations ex. CONFIG_JOSE_PUBLIC.

let did_doc = key.get_did_document(Config {
  use_jose_format: true,    // toggle to switch between LD and JOSE key format
  serialize_secrets: false  // toggle to serialize private keys
});

// or use predefined configs

let did_doc = key.get_did_document(CONFIG_JOSE_PUBLIC);

Example JSON-LD output

{
  "@context": "https://www.w3.org/ns/did/v1",
  "id": "did:key:z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL",
  "assertionMethod": [
    "did:key:z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL#z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL"
  ],
  "authentication": [
    "did:key:z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL#z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL"
  ],
  "capabilityDelegation": [
    "did:key:z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL#z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL"
  ],
  "capabilityInvocation": [
    "did:key:z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL#z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL"
  ],
  "keyAgreement": [
    "did:key:z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL#z6LSrdqo4M24WRDJj1h2hXxgtDTyzjjKCiyapYVgrhwZAySn"
  ],
  "verificationMethod": [
    {
      "id": "did:key:z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL#z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL",
      "type": "Ed25519VerificationKey2018",
      "controller": "did:key:z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL",
      "publicKeyBase58": "6fioC1zcDPyPEL19pXRS2E4iJ46zH7xP6uSgAaPdwDrx"
    },
    {
      "id": "did:key:z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL#z6LSrdqo4M24WRDJj1h2hXxgtDTyzjjKCiyapYVgrhwZAySn",
      "type": "X25519KeyAgreementKey2019",
      "controller": "did:key:z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL",
      "publicKeyBase58": "FxfdY3DCQxVZddKGAtSjZdFW9bCCW7oRwZn1NFJ2Tbg2"
    }
  ]
}

Example JSON output

{
  "@context": "https://www.w3.org/ns/did/v1",
  "id": "did:key:z6LSfaBhhoYmAMX11m9xYCaeaU99KPtYnzHpsWD6iNWbJDr2",
  "keyAgreement": [
    "did:key:z6LSfaBhhoYmAMX11m9xYCaeaU99KPtYnzHpsWD6iNWbJDr2#z6LSfaBhhoYmAMX11m9xYCaeaU99KPtYnzHpsWD6iNWbJDr2"
  ],
  "verificationMethod": [
    {
      "id": "did:key:z6LSfaBhhoYmAMX11m9xYCaeaU99KPtYnzHpsWD6iNWbJDr2#z6LSfaBhhoYmAMX11m9xYCaeaU99KPtYnzHpsWD6iNWbJDr2",
      "controller": "did:key:z6LSfaBhhoYmAMX11m9xYCaeaU99KPtYnzHpsWD6iNWbJDr2",
      "type": "JsonWebKey2020",
      "publicKeyJwk": {
        "kty": "OKP",
        "crv": "X25519",
        "x": "OeXe54Y0Dnk0WNWsQ6PqKUBB2x6bos0DZ_WkdFNdt3M"
      }
    }
  ]
}

Benchmarks

Crate includes some basic benchmarks for key generation and exchange comparison, using criterion. To run the benchmarks:

cargo bench

License

Apache License 2.0

Contributions

...are most welcome! 🙌