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.

Supported Key Types

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

Usage

Install from crates.io

did-key = "0.0.3"

To resolve a did formatted URI:

use did_key::*;

let key = DIDKey::resolve("did:key:z6Mkk7yqnGF3YwTrLpqrW6PGsKci7dNqh1CjnvMbzrMerSeL").unwrap();

Generate new key:

let key = DIDKey::new(DIDKeyType::Ed25519);

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

Sign and verify:

let key = DIDKey::new(DIDKeyType::P256);
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 = DIDKey::new(DIDKeyType::Ed25519);
let did_doc = key.to_did_document();

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

The default json format is JSON-LD. To serialize a document using JSON format (using JWK key types), toggle the CONTENT_TYPE static.

unsafe { did_key::CONTENT_TYPE = did_key::ContentType::Json; }

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! 🙌