key-did-resolver

did:key Method Resolver

This package contains did:key method resolver implementation

Installation

$ npm install key-did-resolver

Usage

This code includes support for the curves Ed25519, Secp256k1, Secp256r1 (P-256), Secp384r1 (P-384), and Secp521r1 (P-521) which follow the test vectors at: https://github.com/w3c-ccg/did-method-key/tree/main/test-vectors

This code has been tested with the following did:key¹ providers:

Curve	Repository
Ed25519	https://github.com/ceramicnetwork/js-did/tree/main/packages/key-did-provider-ed25519 (EIP-2844 RPC)
Secp256k1	https://github.com/ceramicnetwork/js-did/tree/main/packages/key-did-provider-secp256k1 (JWE not supported)
P-256, P-384, P-521	https://github.com/bshambaugh/did-key-creator (public key to did:key only)
P-256	https://github.com/bshambaugh/key-did-provider-p256 (EIP-2844 RPC, JWE not yet implemented)

Compressed² forms of P-256, P-384, and P-521 are preferred. ³

Code

Using with secp256k1 did-key:

import * as KeyDidResolver from 'key-did-resolver'
import {Resolver} from 'did-resolver'

const keyDidResolver = KeyDIDResolver.getResolver()
console.log(keyDidResolver)
const didResolver = new Resolver(keyDidResolver)
const doc = await didResolver.resolve('did:key:z6MktvqCyLxTsXUH1tUZncNdVeEZ7hNh7npPRbUU27GTrYb8')

console.log(doc)
console.log(doc.didDocument.verificationMethod)

Output

Using with secp256k1 did-key:

{
  didResolutionMetadata: { contentType: 'application/did+json' },
  didDocument: {
    id: 'did:key:zQ3shokFTS3brHcDQrn82RUDfCZESWL1ZdCEJwekUDPQiYBme',
    verificationMethod: [ [Object] ],
    authentication: [
      'did:key:zQ3shokFTS3brHcDQrn82RUDfCZESWL1ZdCEJwekUDPQiYBme#zQ3shokFTS3brHcDQrn82RUDfCZESWL1ZdCEJwekUDPQiYBme'
    ],
    assertionMethod: [
      'did:key:zQ3shokFTS3brHcDQrn82RUDfCZESWL1ZdCEJwekUDPQiYBme#zQ3shokFTS3brHcDQrn82RUDfCZESWL1ZdCEJwekUDPQiYBme'
    ],
    capabilityDelegation: [
      'did:key:zQ3shokFTS3brHcDQrn82RUDfCZESWL1ZdCEJwekUDPQiYBme#zQ3shokFTS3brHcDQrn82RUDfCZESWL1ZdCEJwekUDPQiYBme'
    ],
    capabilityInvocation: [
      'did:key:zQ3shokFTS3brHcDQrn82RUDfCZESWL1ZdCEJwekUDPQiYBme#zQ3shokFTS3brHcDQrn82RUDfCZESWL1ZdCEJwekUDPQiYBme'
    ]
  },
  didDocumentMetadata: {}
}
[
  {
    id: 'did:key:zQ3shokFTS3brHcDQrn82RUDfCZESWL1ZdCEJwekUDPQiYBme#zQ3shokFTS3brHcDQrn82RUDfCZESWL1ZdCEJwekUDPQiYBme',
    type: 'Secp256k1VerificationKey2018',
    controller: 'did:key:zQ3shokFTS3brHcDQrn82RUDfCZESWL1ZdCEJwekUDPQiYBme',
    publicKeyBase58: '23o6Sau8NxxzXcgSc3PLcNxrzrZpbLeBn1izfv3jbKhuv'
  }
]

The code for other curves is similar. Changing the did:key string is sufficient.

code snippet for ed25519

const doc = await didResolver.resolve('did:key:z6MktvqCyLxTsXUH1tUZncNdVeEZ7hNh7npPRbUU27GTrYb8')

code snippet for P-256

const doc = await didResolver.resolve('did:key:zDnaeUKTWUXc1HDpGfKbEK31nKLN19yX5aunFd7VK1CUMeyJu')

code snippet for P-384

const doc = await didResolver.resolve('did:key:z82LkvCwHNreneWpsgPEbV3gu1C6NFJEBg4srfJ5gdxEsMGRJUz2sG9FE42shbn2xkZJh54')

code snippet for P-521

const doc = await didResolver.resolve('did:key:z2J9gcGhudjgwsDLv4qJVM6DysnsjWRS6ggtCsSYpV9TGxd9WGoE1EkPxdvPcqEs7eLsQA985AGXPuqttPP7WJ5Qdiz27U3t')

Note: All P-*** curves are compressed

The verification method results are slightly different. Here is a sampling:

did document verificationMethod for ed25519:

[
  {
    id: 'did:key:z6MktvqCyLxTsXUH1tUZncNdVeEZ7hNh7npPRbUU27GTrYb8#z6MktvqCyLxTsXUH1tUZncNdVeEZ7hNh7npPRbUU27GTrYb8',
    type: 'Ed25519VerificationKey2018',
    controller: 'did:key:z6MktvqCyLxTsXUH1tUZncNdVeEZ7hNh7npPRbUU27GTrYb8',
    publicKeyBase58: 'FUaAP6i2XyyouPds73QneYgZJ86qhua2jaZYBqJSwKok'
  }
]

did document verificationMethod for P-256:

[
  {
    id: 'did:key:zDnaeUKTWUXc1HDpGfKbEK31nKLN19yX5aunFd7VK1CUMeyJu#zDnaeUKTWUXc1HDpGfKbEK31nKLN19yX5aunFd7VK1CUMeyJu',
    type: 'JsonWebKey2020',
    controller: 'did:key:zDnaeUKTWUXc1HDpGfKbEK31nKLN19yX5aunFd7VK1CUMeyJu',
    publicKeyJwk: {
      kty: 'EC',
      crv: 'P-256',
      x: 'OcPddBMXKURtwbPaZ9SfwEb8vwcvzFufpRwFuXQwf5Y',
      y: 'nEA7FjXwRJ8CvUInUeMxIaRDTxUvKysqP2dSGcXZJfY'
    }
  }
]

did document verificationMethod for P-384:

[
  {
    id: 'did:key:z82LkvCwHNreneWpsgPEbV3gu1C6NFJEBg4srfJ5gdxEsMGRJUz2sG9FE42shbn2xkZJh54#z82LkvCwHNreneWpsgPEbV3gu1C6NFJEBg4srfJ5gdxEsMGRJUz2sG9FE42shbn2xkZJh54',
    type: 'JsonWebKey2020',
    controller: 'did:key:z82LkvCwHNreneWpsgPEbV3gu1C6NFJEBg4srfJ5gdxEsMGRJUz2sG9FE42shbn2xkZJh54',
    publicKeyJwk: {
      kty: 'EC',
      crv: 'P-384',
      x: 'CA-iNoHDg1lL8pvX3d1uvExzVfCz7Rn6tW781Ub8K5MrDf2IMPyL0RTDiaLHC1JT',
      y: 'Kpnrn8DkXUD3ge4mFxi-DKr0DYO2KuJdwNBrhzLRtfMa3WFMZBiPKUPfJj8dYNl_'
    }
  }
]

did document verificationMethod for P-521:

[
  {
    id: 'did:key:z2J9gcGhudjgwsDLv4qJVM6DysnsjWRS6ggtCsSYpV9TGxd9WGoE1EkPxdvPcqEs7eLsQA985AGXPuqttPP7WJ5Qdiz27U3t#z2J9gcGhudjgwsDLv4qJVM6DysnsjWRS6ggtCsSYpV9TGxd9WGoE1EkPxdvPcqEs7eLsQA985AGXPuqttPP7WJ5Qdiz27U3t',
    type: 'JsonWebKey2020',
    controller: 'did:key:z2J9gcGhudjgwsDLv4qJVM6DysnsjWRS6ggtCsSYpV9TGxd9WGoE1EkPxdvPcqEs7eLsQA985AGXPuqttPP7WJ5Qdiz27U3t',
    publicKeyJwk: {
      kty: 'EC',
      crv: 'P-521',
      x: 'ATkofCC8_KAAJ3XSRayyPk8WqF9qahhoQVjbHtzbe5MSaaFiMKBZr-CurF9IcpJD-YYEukPmarSKFpXLtwAdiONT',
      y: 'AWuYkJ7iaFhfz_dzFemaBnuq1WFnoZeIha7KpE9benPTX9FQhAoyHY-2qO4IyqGe1XGGtx8eJXvp57xMtUXm2rAH'
    }
 }
]

Testing

Due to problems with parsing JSON with BigInt, tests need to be run with Jest in Serial mode. Use npm run test -- --runInBand .

References

[Standards for Efficient Cryptography SEC 2: Recommended Elliptic Curve Domain Parameters Certicom Research Contact: Daniel R. L. Brown ([e-mail]) January 27, 2010 Version 2.0 ], http://www.secg.org/sec2-v2.pdf

[FIPS PUB 186-4 ,FEDERAL INFORMATION PROCESSING STANDARDS PUBLICATION, Digital Signature Standard (DSS)], https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf

[Compact representation of an elliptic curve point, Network Working Group, A.J. Jivsov, March 15, 2014], https://datatracker.ietf.org/doc/html/draft-jivsov-ecc-compact-05

Additional Usage Notes

See the dids developer site for more details about how to use this package.

Contributing

We are happy to accept small and large contributions.

License

Apache-2.0 OR MIT

Footnotes

• The syntax of a did:key is did:key:id. The did:key id is the base58btc string representation of the Uint8Array (byte array) consisting of the the multicodec name followed by the public key {raw,uncompressed,compressed}. ↩

• Compressed keys are the X coordinate of the public key with a prefix that depends on the sign of the Y curve coordinate. The prefix is '02' if even and '03' if odd. ↩

• During development there was not yet consensus on using all compressed keys. Support for uncompressed keys with the '04' prefix and raw keys (just the x,y bytes with no prefix) was kept for the P-256 and P-384 curves. ↩