feat: add Multikey as supported vm type

packages/core/src/modules/dids/domain/key-type/__tests__/ed25519.test.ts

@@ -56,6 +56,7 @@ describe('ed25519', () => {
       'Ed25519VerificationKey2018',
       'Ed25519VerificationKey2020',
       'JsonWebKey2020',
+      'Multikey',
     ])
   })
 

packages/core/src/modules/dids/domain/key-type/__tests__/x25519.test.ts

@@ -52,7 +52,11 @@ describe('x25519', () => {
   })
 
   it('supports X25519KeyAgreementKey2019 verification method type', () => {
-    expect(keyDidX25519.supportedVerificationMethodTypes).toMatchObject(['X25519KeyAgreementKey2019', 'JsonWebKey2020'])
+    expect(keyDidX25519.supportedVerificationMethodTypes).toMatchObject([
+      'X25519KeyAgreementKey2019',
+      'JsonWebKey2020',
+      'Multikey',
+    ])
   })
 
   it('returns key for X25519KeyAgreementKey2019 verification method', () => {

packages/core/src/modules/dids/domain/key-type/ed25519.ts

@@ -11,9 +11,12 @@ import {
   isEd25519VerificationKey2020,
   isJsonWebKey2020,
   getEd25519VerificationKey2018,
+  getKeyFromMultikey,
+  isMultikey,
   VERIFICATION_METHOD_TYPE_ED25519_VERIFICATION_KEY_2018,
   VERIFICATION_METHOD_TYPE_ED25519_VERIFICATION_KEY_2020,
   VERIFICATION_METHOD_TYPE_JSON_WEB_KEY_2020,
+  VERIFICATION_METHOD_TYPE_MULTIKEY,
 } from '../verificationMethod'
 
 export { convertPublicKeyToX25519 } from '@stablelib/ed25519'
@@ -23,6 +26,7 @@ export const keyDidEd25519: KeyDidMapping = {
     VERIFICATION_METHOD_TYPE_ED25519_VERIFICATION_KEY_2018,
     VERIFICATION_METHOD_TYPE_ED25519_VERIFICATION_KEY_2020,
     VERIFICATION_METHOD_TYPE_JSON_WEB_KEY_2020,
+    VERIFICATION_METHOD_TYPE_MULTIKEY,
   ],
   getVerificationMethods: (did, key) => [
     getEd25519VerificationKey2018({ id: `${did}#${key.fingerprint}`, key, controller: did }),
@@ -40,6 +44,10 @@ export const keyDidEd25519: KeyDidMapping = {
       return getKeyFromJsonWebKey2020(verificationMethod)
     }
 
+    if (isMultikey(verificationMethod)) {
+      return getKeyFromMultikey(verificationMethod)
+    }
+
     throw new AriesFrameworkError(
       `Verification method with type '${verificationMethod.type}' not supported for key type '${KeyType.Ed25519}'`
     )

packages/core/src/modules/dids/domain/key-type/keyDidMapping.ts

@@ -1,9 +1,14 @@
 import type { Key } from '../../../../crypto/Key'
-import type { VerificationMethod } from '../verificationMethod'
 
 import { KeyType } from '../../../../crypto/KeyType'
 import { getJwkFromJson } from '../../../../crypto/jose/jwk'
 import { AriesFrameworkError } from '../../../../error'
+import {
+  VERIFICATION_METHOD_TYPE_MULTIKEY,
+  isMultikey,
+  type VerificationMethod,
+  getKeyFromMultikey,
+} from '../verificationMethod'
 import { isJsonWebKey2020, VERIFICATION_METHOD_TYPE_JSON_WEB_KEY_2020 } from '../verificationMethod/JsonWebKey2020'
 
 import { keyDidBls12381g1 } from './bls12381g1'
@@ -67,7 +72,7 @@ export function getKeyDidMappingByKeyType(keyType: KeyType) {
   return keyDid
 }
 
-export function getKeyFromVerificationMethod(verificationMethod: VerificationMethod) {
+export function getKeyFromVerificationMethod(verificationMethod: VerificationMethod): Key {
   // This is a special verification method, as it supports basically all key types.
   if (isJsonWebKey2020(verificationMethod)) {
     // TODO: move this validation to another place
@@ -80,6 +85,16 @@ export function getKeyFromVerificationMethod(verificationMethod: VerificationMet
     return getJwkFromJson(verificationMethod.publicKeyJwk).key
   }
 
+  if (isMultikey(verificationMethod)) {
+    if (!verificationMethod.publicKeyMultibase) {
+      throw new AriesFrameworkError(
+        `Missing publicKeyMultibase on verification method with type ${VERIFICATION_METHOD_TYPE_MULTIKEY}`
+      )
+    }
+
+    return getKeyFromMultikey(verificationMethod)
+  }
+
   const keyDid = verificationMethodKeyDidMapping[verificationMethod.type]
   if (!keyDid) {
     throw new AriesFrameworkError(`Unsupported key did from verification method type '${verificationMethod.type}'`)

packages/core/src/modules/dids/domain/key-type/x25519.ts

@@ -11,12 +11,16 @@ import {
   getKeyFromJsonWebKey2020,
   isJsonWebKey2020,
   VERIFICATION_METHOD_TYPE_JSON_WEB_KEY_2020,
+  VERIFICATION_METHOD_TYPE_MULTIKEY,
+  isMultikey,
+  getKeyFromMultikey,
 } from '../verificationMethod'
 
 export const keyDidX25519: KeyDidMapping = {
   supportedVerificationMethodTypes: [
     VERIFICATION_METHOD_TYPE_X25519_KEY_AGREEMENT_KEY_2019,
     VERIFICATION_METHOD_TYPE_JSON_WEB_KEY_2020,
+    VERIFICATION_METHOD_TYPE_MULTIKEY,
   ],
   getVerificationMethods: (did, key) => [
     getX25519KeyAgreementKey2019({ id: `${did}#${key.fingerprint}`, key, controller: did }),
@@ -30,6 +34,10 @@ export const keyDidX25519: KeyDidMapping = {
       return getKeyFromX25519KeyAgreementKey2019(verificationMethod)
     }
 
+    if (isMultikey(verificationMethod)) {
+      return getKeyFromMultikey(verificationMethod)
+    }
+
     throw new AriesFrameworkError(
       `Verification method with type '${verificationMethod.type}' not supported for key type '${KeyType.X25519}'`
     )

packages/core/src/modules/dids/domain/verificationMethod/Multikey.ts

@@ -0,0 +1,50 @@
+import type { VerificationMethod } from './VerificationMethod'
+
+import { Key } from '../../../../crypto/Key'
+import { AriesFrameworkError } from '../../../../error'
+
+export const VERIFICATION_METHOD_TYPE_MULTIKEY = 'Multikey'
+
+type GetMultikeyOptions = {
+  did: string
+  key: Key
+  verificationMethodId?: string
+}
+
+/**
+ * Get a Multikey verification method.
+ */
+export function getMultikey({ did, key, verificationMethodId }: GetMultikeyOptions) {
+  if (!verificationMethodId) {
+    verificationMethodId = `${did}#${key.fingerprint}`
+  }
+
+  return {
+    id: verificationMethodId,
+    type: VERIFICATION_METHOD_TYPE_MULTIKEY,
+    controller: did,
+    publicKeyMultibase: key.fingerprint,
+  }
+}
+
+/**
+ * Check whether a verification method is a Multikey verification method.
+ */
+export function isMultikey(
+  verificationMethod: VerificationMethod
+): verificationMethod is VerificationMethod & { type: 'Multikey' } {
+  return verificationMethod.type === VERIFICATION_METHOD_TYPE_MULTIKEY
+}
+
+/**
+ * Get a key from a Multikey verification method.
+ */
+export function getKeyFromMultikey(verificationMethod: VerificationMethod & { type: 'Multikey' }) {
+  if (!verificationMethod.publicKeyMultibase) {
+    throw new AriesFrameworkError(
+      `Missing publicKeyMultibase on verification method with type ${VERIFICATION_METHOD_TYPE_MULTIKEY}`
+    )
+  }
+
+  return Key.fromFingerprint(verificationMethod.publicKeyMultibase)
+}

packages/core/src/modules/dids/domain/verificationMethod/index.ts

@@ -7,3 +7,4 @@ export * from './Ed25519VerificationKey2018'
 export * from './Ed25519VerificationKey2020'
 export * from './JsonWebKey2020'
 export * from './X25519KeyAgreementKey2019'
+export * from './Multikey'