fix(utils): convert JWK with curv Ed25519 to X25519 (#1078)

decentralized-identity · Dec 5, 2022 · deb546b · deb546b
1 parent 32a0f97
commit deb546b
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Showing 2 changed files with 96 additions and 3 deletions.
diff --git a/packages/did-comm/src/__tests__/packing.test.ts b/packages/did-comm/src/__tests__/packing.test.ts
@@ -134,6 +134,63 @@ const hexDoc = {
   ]
 }
 
+// https://github.com/aviarytech/didcomm/blob/master/tests/fixtures/didDocs/alice.json
+const jwkDocX = {
+	"@context": ["https://www.w3.org/ns/did/v1", "https://w3id.org/security/suites/jws-2020/v1"],
+	"id": "did:example:alice",
+	"verificationMethod": [
+		{
+			"id": "did:example:alice#key-0",
+			"controller": "did:example:alice",
+			"type": "JsonWebKey2020",
+			"publicKeyJwk": {
+				"kty": "OKP",
+				"crv": "X25519",
+				"x": "tsc9iYfy4hv2Mz5Q-ztGjKXeXzWUDWl5DLpfepJg4Wc"
+			}
+		}
+	],
+	"authentication": ["did:example:alice#key-0"],
+	"assertionMethod": ["did:example:alice#key-0"],
+	"keyAgreement": ["did:example:alice#key-0"],
+	"service": [
+		{
+			"id": "did:example:alice#didcomm",
+			"type": "DIDCommMessaging",
+			"serviceEndpoint": "http://example.com/didcomm",
+			"routingKeys": []
+		}
+	]
+}
+
+const jwkDocEd = {
+	"@context": ["https://www.w3.org/ns/did/v1", "https://w3id.org/security/suites/jws-2020/v1"],
+	"id": "did:example:alice",
+	"verificationMethod": [
+		{
+			"id": "did:example:alice#key-0",
+			"controller": "did:example:alice",
+			"type": "JsonWebKey2020",
+			"publicKeyJwk": {
+				"kty": "OKP",
+				"crv": "Ed25519",
+				"x": "CV-aGlld3nVdgnhoZK0D36Wk-9aIMlZjZOK2XhPMnkQ"
+			}
+		}
+	],
+	"authentication": ["did:example:alice#key-0"],
+	"assertionMethod": ["did:example:alice#key-0"],
+	"keyAgreement": ["did:example:alice#key-0"],
+	"service": [
+		{
+			"id": "did:example:alice#didcomm",
+			"type": "DIDCommMessaging",
+			"serviceEndpoint": "http://example.com/didcomm",
+			"routingKeys": []
+		}
+	]
+}
+
 describe('didComm', () => {
   let didKeyIdentifier: IIdentifier
   let agent: TAgent<IResolver & IKeyManager & IDIDManager>
@@ -165,6 +222,10 @@ describe('didComm', () => {
                 doc = multiBaseDoc
               } else if (did === "did:fake:hex") {
                 doc = hexDoc
+              } else if (did === "did:fake:jwkx") {
+                doc = jwkDocX
+              } else if (did === "did:fake:jwked") {
+                doc = jwkDocEd
               } else {
                 throw new Error("Bad didUrl for fake resolver: " + did)
               }
@@ -202,6 +263,8 @@ describe('didComm', () => {
     expect(packedMessage).toBeDefined()
   })
 
+  it.todo('should unpack message packed for base58')
+
   it('should pack message for public key as multibase', async () => {
     const packedMessage = await agent.packDIDCommMessage({
       message: testMessage("did:fake:multibase"),
@@ -210,11 +273,35 @@ describe('didComm', () => {
     expect(packedMessage).toBeDefined()
   })
 
+  it.todo('should unpack message packed for multibase')
+
   it('should pack message for public key as hex', async () => {
     const packedMessage = await agent.packDIDCommMessage({
       message: testMessage("did:fake:hex"),
       packing: 'authcrypt'
     })
     expect(packedMessage).toBeDefined()
   })
+
+  it.todo('should unpack message packed for hex')
+
+  it('should pack message for public key as jwk with X25519 crv', async () => {
+    const packedMessage = await agent.packDIDCommMessage({
+      message: testMessage("did:fake:jwkx"),
+      packing: 'authcrypt'
+    })
+    expect(packedMessage).toBeDefined()
+  })
+
+  it.todo('should unpack message packed for jwk with X25519 crv')
+
+  it('should pack message for public key as jwk with Ed25519 crv', async () => {
+    const packedMessage = await agent.packDIDCommMessage({
+      message: testMessage("did:fake:jwked"),
+      packing: 'authcrypt'
+    })
+    expect(packedMessage).toBeDefined()
+  })
+
+  it.todo('should unpack message packed for jwk with Ed25519 crv')
 })
diff --git a/packages/utils/src/did-utils.ts b/packages/utils/src/did-utils.ts
@@ -159,7 +159,7 @@ function extractPublicKeyBytes(pk: VerificationMethod): Uint8Array {
     )
   } else if (
     pk.publicKeyJwk &&
-    pk.publicKeyJwk.crv === 'Ed25519' &&
+    (pk.publicKeyJwk.crv === 'Ed25519' || pk.publicKeyJwk.crv === 'X25519') &&
     pk.publicKeyJwk.x
   ) {
     return base64ToBytes(pk.publicKeyJwk.x)
@@ -311,9 +311,15 @@ export async function dereferenceDidKeys(
       const hexKey = extractPublicKeyHex(key, convert)
       const { publicKeyHex, publicKeyBase58, publicKeyMultibase, publicKeyBase64, publicKeyJwk, ...keyProps } = key
       const newKey = { ...keyProps, publicKeyHex: hexKey }
+
+      // With a JWK `key`, `newKey` does not have information about crv (Ed25519 vs X25519)
+      // Should type of `newKey` change?
       if (convert && 'Ed25519VerificationKey2018' === newKey.type) {
         newKey.type = 'X25519KeyAgreementKey2019'
+      } else if (convert && 'Ed25519VerificationKey2020' === newKey.type) {
+        newKey.type = 'X25519KeyAgreementKey2020'
       }
+
       return newKey
     })
 }
@@ -330,9 +336,9 @@ export async function dereferenceDidKeys(
 export function extractPublicKeyHex(pk: _ExtendedVerificationMethod, convert: boolean = false): string {
   let keyBytes = extractPublicKeyBytes(pk)
   if (convert) {
-    if (['Ed25519', 'Ed25519VerificationKey2018', 'Ed25519VerificationKey2020'].includes(pk.type)) {
+    if (['Ed25519', 'Ed25519VerificationKey2018', 'Ed25519VerificationKey2020'].includes(pk.type) || (pk.type === 'JsonWebKey2020' && pk.publicKeyJwk?.crv === 'Ed25519')) {
       keyBytes = convertPublicKeyToX25519(keyBytes)
-    } else if (!['X25519', 'X25519KeyAgreementKey2019', 'X25519KeyAgreementKey2020'].includes(pk.type)) {
+    } else if (!['X25519', 'X25519KeyAgreementKey2019', 'X25519KeyAgreementKey2020'].includes(pk.type) && !(pk.type === 'JsonWebKey2020' && pk.publicKeyJwk?.crv === 'X25519')) {
       return ''
     }
   }