resolveDidKey function

DidDocument resolveDidKey(String did)

Implementation

DidDocument resolveDidKey(String did) {
  if (!did.startsWith('did:key')) {
    throw Exception(
        'Expected did to start with `did:key`. However `$did` did not');
  }
  var splited = did.split(':');
  if (splited.length != 3) throw Exception('malformed did: `$did`');

  String keyPart = splited[2];
  var multibaseIndicator = keyPart[0];
  keyPart = keyPart.substring(1);

  var context = [
    "https://www.w3.org/ns/did/v1",
    "https://w3id.org/security/suites/ed25519-2020/v1",
    "https://w3id.org/security/suites/x25519-2020/v1"
  ];

  var context2 = [
    "https://www.w3.org/ns/did/v1",
    'https://ns.did.ai/suites/multikey-2021/v1/'
  ];

  var id = did;

  if (multibaseIndicator != 'z') {
    throw UnimplementedError('Only Base58 is supported yet');
  }

  if (keyPart.startsWith('6Mk')) {
    return _buildEDDoc(context, id, keyPart);
  } else if (keyPart.startsWith('6LS')) {
    return _buildXDoc(context, id, keyPart);
  } else if (keyPart.startsWith('Dn')) {
    return _buildOtherDoc(context2, id, keyPart, 'P256Key2021');
  } else if (keyPart.startsWith('Q3s')) {
    return _buildOtherDoc(context2, id, keyPart, 'Secp256k1Key2021');
  } else if (keyPart.startsWith('82')) {
    return _buildOtherDoc(context2, id, keyPart, 'P384Key2021');
  } else if (keyPart.startsWith('2J9')) {
    return _buildOtherDoc(context2, id, keyPart, 'P521Key2021');
  } else {
    throw UnimplementedError('Only Ed25519 and X25519 keys are supported now');
  }
}