oidc-lib/src/claimer_sts/did_management.js

A library for creating OIDC Service Providers

var pk;

module.exports = {
	registerEndpoints: registerEndpoints,
	create: create,
	didFromJwk: didFromJwk
}

function registerEndpoints(pkInput){
	pk = pkInput;
}

async function didFromJwk(didSchemePlusMethod, jwk){
	var potential_error = 'config error ';

	try{
		if (!didSchemePlusMethod.startsWith('did:')){
			throw ('didSchemePlusMethod in didFromJwk is not a did');
		}
		var method = didSchemePlusMethod.substr(4);
		var method_len = method.indexOf(':');
		if (method_len > 0){
			method = method.substr(0, method_len);
		}

		if (method !== "peer"){
			throw ("'" + method + "' did_method not implemented ");
		}

		var fauxKeyObject = new pk.key_management.claimerKeyObject('wallet', pk.key_management.PERSONAKEY, jwk.kty, jwk.alg, jwk.crv);
		fauxKeyObject.jwk_public = jwk;
		var did = create(null, method, fauxKeyObject);

		return did;
	}
	catch(err){
		throw ("did_management.didFromJwk: " + potential_error + " - " + err);
	}
}

async function create(dbInfo, did_method, keyObject){
	var potential_error = 'config error ';
	try{
		if (did_method !== "peer"){
			throw ("'" + did_method + "' did_method not implemented ");
		}

		// todo:  figure out ambiguity re: oct/OKP and EC/EdDSA
		switch (keyObject.kty){
			case 'EC':
			case 'oct':
				var did_x_bytes = pk.base64url.toBuffer(keyObject.jwk_public.x);
				var did_y_bytes = pk.base64url.toBuffer(keyObject.jwk_public.y);
				// msi stands for method specific identifier in the DID
				var did_msi_buf = new Uint8Array(did_x_bytes.length + 
					did_y_bytes.length + keyObject.multicodec_bytes.length);
				var j = 0;
				for (var i = 0; i < keyObject.multicodec_bytes.length; i++){
					did_msi_buf[j++] = keyObject.multicodec_bytes[i];
				}
				for (var i = 0; i < did_x_bytes.length; i++){
					did_msi_buf[j++] = did_x_bytes[i];
				}
				for (var i = 0; i < did_y_bytes.length; i++){
					did_msi_buf[j++] = did_y_bytes[i];
				}
				break;

			case 'EdDSA':
			case 'OKP':
				var did_x_bytes = pk.base64url.toBuffer(keyObject.jwk_public.x);
				var did_msi_buf = new Uint8Array(did_x_bytes.length + 
					keyObject.multicodec_bytes.length);
				var j = 0;
				for (var i = 0; i < keyObject.multicodec_bytes.length; i++){
					did_msi_buf[j++] = keyObject.multicodec_bytes[i];
				}
				for (var i = 0; i < did_x_bytes.length; i++){
					did_msi_buf[j++] = did_x_bytes[i];
				}
				break;


			dafault:
				throw ("'" + keyObject.kty + "' kty keys are not implented in the peer did method");		
		}

		keyObject.did = 'did:peer:z0'+  pk.base58.encode(did_msi_buf);

		if (dbInfo){
			await dbInfo.provider.createOrUpdateDocument(
					dbInfo, 'keys', keyObject, null);
		}


		return keyObject.did;
	}
	catch(err){
		throw ("did_management.create: " + potential_error + " - " + err);
	}
}

function decodeSuffix(did){
	if (!did){
		return;
	}
	var encoding = did.substr(10);
	return base58.decode(encoding);
}


var didDocumentTemplate = {
  "@context": "https://w3id.org/did/v1",
  "id": "{did_peer}", "publicKey": [{
    "id": "{did_peer}#{keyid}",
    "type": "Ed25519VerificationKey2018",
    "controller": "{did_peer}",
    "publicKeyBase58": "B12NYF8RrR3h41TDCTJojY59usg3mbtbjnFs7Eud1Y6u"
  }],
  "authentication": [ "{did_peer}#{keyid}" ],
  "assertionMethod": [ "{did_peer}#{keyid}" ],
  "capabilityDelegation": [ "{did_peer}#{keyid}" ],
  "capabilityInvocation": [ "{did_peer}#{keyid}" ],
  "keyAgreement": [{
    "id": "{did_peer}#zBzoR5sqFgi6q3iFia8JPNfENCpi7RNSTKF7XNXX96SBY4",
    "type": "X25519KeyAgreementKey2019",
    "controller": "{did_peer}",
    "publicKeyBase58": "JhNWeSVLMYccCk7iopQW4guaSJTojqpMEELgSLhKwRr"
  }]
};