feat(castor) Add did verification capabilities

apollo/src/commonMain/kotlin/ApolloMock.kt

@@ -24,7 +24,7 @@ class ApolloMock : Apollo {
     )
     var publicKeyReturn: PublicKey = PublicKey(KeyCurve(Curve.ED25519), ByteArray(0))
     var signMessageReturn: Signature = Signature(ByteArray(0))
-    var verifySignatureReturn: Boolean = false
+    var verifySignatureReturn: Boolean = true
     var compressedPublicKeyDataReturn: CompressedPublicKey = CompressedPublicKey(
         PublicKey(KeyCurve(Curve.ED25519), ByteArray(0)),
         ByteArray(0)

castor/build.gradle.kts

@@ -77,6 +77,7 @@ kotlin {
                 implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.4.1")
                 implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.4")
                 implementation("io.iohk.atala.prism:didpeer:1.0.0-alpha")
+                implementation(project(":apollo"))
                 implementation(project(":domain"))
             }
         }

castor/src/commonMain/kotlin/CastorImpl.kt

@@ -1,14 +1,19 @@
 package io.iohk.atala.prism.castor
 
+import io.iohk.atala.prism.apollo.ApolloImpl
 import io.iohk.atala.prism.castor.io.iohk.atala.prism.castor.resolvers.PeerDIDResolver
+import io.iohk.atala.prism.domain.buildingBlocks.Apollo
 import io.iohk.atala.prism.domain.buildingBlocks.Castor
 import io.iohk.atala.prism.domain.models.CastorError
 import io.iohk.atala.prism.domain.models.Curve
 import io.iohk.atala.prism.domain.models.DID
 import io.iohk.atala.prism.domain.models.DIDDocument
+import io.iohk.atala.prism.domain.models.DIDDocument.VerificationMethod.Companion.getCurveByType
 import io.iohk.atala.prism.domain.models.DIDResolver
+import io.iohk.atala.prism.domain.models.KeyCurve
 import io.iohk.atala.prism.domain.models.KeyPair
 import io.iohk.atala.prism.domain.models.PublicKey
+import io.iohk.atala.prism.domain.models.Signature
 import io.iohk.atala.prism.mercury.didpeer.DIDCommServicePeerDID
 import io.iohk.atala.prism.mercury.didpeer.VerificationMaterialAgreement
 import io.iohk.atala.prism.mercury.didpeer.VerificationMaterialAuthentication
@@ -21,10 +26,17 @@ import kotlinx.serialization.encodeToString
 import kotlinx.serialization.json.Json
 
 open class CastorImpl : Castor {
+    private val apollo: Apollo
     private var resolvers: Array<DIDResolver> = arrayOf(
         PeerDIDResolver()
     )
 
+    constructor(
+        apollo: Apollo? = null,
+    ) {
+        this.apollo = apollo ?: ApolloImpl()
+    }
+
     override fun parseDID(did: String): DID {
         return DIDParser.parse(did)
     }
@@ -104,6 +116,34 @@ open class CastorImpl : Castor {
     }
 
     override suspend fun verifySignature(did: DID, challenge: ByteArray, signature: ByteArray): Boolean {
-        TODO("Not yet implemented")
+        val document = resolveDID(did.toString())
+        val keyPairs: MutableList<PublicKey> = mutableListOf()
+
+        document.coreProperties
+            .filterIsInstance<DIDDocument.Authentication>()
+            .flatMap { it.verificationMethods.toList() }
+            .mapNotNull {
+                it.publicKeyMultibase?.let { publicKey ->
+                    keyPairs.add(
+                        PublicKey(
+                            curve = KeyCurve(getCurveByType(it.type)),
+                            value = publicKey.encodeToByteArray()
+                        )
+                    )
+                }
+            }
+
+        if (keyPairs.isEmpty()) {
+            throw CastorError.InvalidKeyError()
+        }
+
+        for (keyPair in keyPairs) {
+            val verified = apollo.verifySignature(keyPair, challenge, Signature(signature))
+            if (verified) {
+                return true
+            }
+        }
+
+        return false
     }
 }

castor/src/commonMain/kotlin/io/iohk/atala/prism/castor/resolvers/PeerDIDResolver.kt

@@ -2,23 +2,34 @@ package io.iohk.atala.prism.castor.io.iohk.atala.prism.castor.resolvers
 
 import io.iohk.atala.prism.castor.DIDParser
 import io.iohk.atala.prism.castor.DIDUrlParser
+import io.iohk.atala.prism.domain.models.CastorError
+import io.iohk.atala.prism.domain.models.Curve
 import io.iohk.atala.prism.domain.models.DIDDocument
 import io.iohk.atala.prism.domain.models.DIDDocumentCoreProperty
 import io.iohk.atala.prism.domain.models.DIDResolver
 import io.iohk.atala.prism.mercury.didpeer.DIDCommServicePeerDID
 import io.iohk.atala.prism.mercury.didpeer.DIDDocPeerDID
+import io.iohk.atala.prism.mercury.didpeer.MalformedPeerDIDException
 import io.iohk.atala.prism.mercury.didpeer.VerificationMaterialFormatPeerDID
 import io.iohk.atala.prism.mercury.didpeer.VerificationMethodPeerDID
+import io.iohk.atala.prism.mercury.didpeer.VerificationMethodTypeAgreement
+import io.iohk.atala.prism.mercury.didpeer.VerificationMethodTypeAuthentication
 import io.iohk.atala.prism.mercury.didpeer.resolvePeerDID
 import kotlinx.serialization.decodeFromString
 import kotlinx.serialization.json.Json
 
 class PeerDIDResolver() : DIDResolver {
     override val method: String = "peer"
     override suspend fun resolve(didString: String): DIDDocument {
-        val did = DIDParser.parse(didString)
+        val peerDIDDocument = try {
+            DIDDocPeerDID.fromJson(resolvePeerDID(didString))
+        } catch (e: MalformedPeerDIDException) {
+            throw CastorError.InvalidPeerDIDError()
+        } catch (e: Throwable) {
+            throw CastorError.NotPossibleToResolveDID()
+        }
+
         val coreProperties: MutableList<DIDDocumentCoreProperty> = mutableListOf()
-        val peerDIDDocument = DIDDocPeerDID.fromJson(resolvePeerDID(didString))
 
         coreProperties.add(
             DIDDocument.Authentication(
@@ -55,7 +66,6 @@ class PeerDIDResolver() : DIDResolver {
                         )
                     )
                 }
-                // TODO() To add the OtherService and know which attributes we can extract from it.
             }
         }
 
@@ -65,6 +75,8 @@ class PeerDIDResolver() : DIDResolver {
             )
         )
 
+        val did = DIDParser.parse(didString)
+
         return DIDDocument(
             id = did,
             coreProperties = coreProperties.toTypedArray()
@@ -77,7 +89,24 @@ class PeerDIDResolver() : DIDResolver {
     ): DIDDocument.VerificationMethod {
         val didUrl = DIDUrlParser.parse(did)
         val controller = DIDParser.parse(verificationMethod.controller)
-        val type = verificationMethod.verMaterial.type.value
+        val type = when (verificationMethod.verMaterial.type.value) {
+            VerificationMethodTypeAuthentication.ED25519_VERIFICATION_KEY_2020.value -> {
+                Curve.ED25519.value
+            }
+            VerificationMethodTypeAuthentication.ED25519_VERIFICATION_KEY_2018.value -> {
+                Curve.ED25519.value
+            }
+            VerificationMethodTypeAgreement.X25519_KEY_AGREEMENT_KEY_2020.value -> {
+                Curve.X25519.value
+            }
+            VerificationMethodTypeAgreement.X25519_KEY_AGREEMENT_KEY_2019.value -> {
+                Curve.X25519.value
+            }
+            else -> {
+                throw CastorError.InvalidKeyError()
+            }
+        }
+
         return when (verificationMethod.verMaterial.format) {
             VerificationMaterialFormatPeerDID.JWK -> {
                 DIDDocument.VerificationMethod(

castor/src/commonTest/kotlin/io/iohk/atala/prism/castor/DIDResolverTest.kt

@@ -1,8 +1,7 @@
 package io.iohk.atala.prism.castor
 
+import io.iohk.atala.prism.domain.models.Curve
 import io.iohk.atala.prism.domain.models.DIDDocument
-import io.iohk.atala.prism.mercury.didpeer.VerificationMethodTypeAgreement
-import io.iohk.atala.prism.mercury.didpeer.VerificationMethodTypeAuthentication
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.test.runTest
 import kotlin.test.Test
@@ -31,7 +30,7 @@ class DIDResolverTest {
                             assertEquals(verificationMethod.id.did.toString(), didExample)
                             assertEquals(
                                 verificationMethod.type,
-                                VerificationMethodTypeAuthentication.ED25519_VERIFICATION_KEY_2020.value
+                                Curve.ED25519.value
                             )
                         }
                     }
@@ -44,7 +43,7 @@ class DIDResolverTest {
                             assertEquals(verificationMethod.id.did.toString(), didExample)
                             assertEquals(
                                 verificationMethod.type,
-                                VerificationMethodTypeAgreement.X25519_KEY_AGREEMENT_KEY_2020.value
+                                Curve.X25519.value
                             )
                         }
                     }

castor/src/commonTest/kotlin/io/iohk/atala/prism/castor/DIDSignatureVerificationTest.kt

@@ -0,0 +1,40 @@
+package io.iohk.atala.prism.castor
+
+import io.iohk.atala.prism.apollo.ApolloMock
+import io.iohk.atala.prism.domain.models.CastorError
+import kotlinx.coroutines.test.runTest
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
+
+class DIDSignatureVerificationTest {
+
+    @Test
+    fun testCastorVerifySignature_Should_return_true_when_correctKeysAreUsed() = runTest {
+        val verKeyStr = "z6LSci5EK4Ezue5QA72ZX71QUbXY2xr5ygRw7wM1WJigTNnd"
+        val authKeyStr = "z6MkqgCXHEGr2wJZANPZGC8WFmeVuS3abAD9uvh7mTXygCFv"
+        val serviceStr = "eyJpZCI6IkRJRENvbW1WMiIsInQiOiJkbSIsInMiOiJsb2NhbGhvc3Q6ODA4MiIsInIiOltdLCJhIjpbImRtIl19"
+        val didString = "did:peer:2.E$verKeyStr.V$authKeyStr.S$serviceStr"
+
+        val castor = CastorImpl(ApolloMock())
+
+        val did = DIDParser.parse(didString)
+        val result = castor.verifySignature(did, "".encodeToByteArray(), "".encodeToByteArray())
+        assertEquals(true, result)
+    }
+
+    @Test
+    fun testCastorVerifySignature_Should_return_error_when_incorrectKeysAreUsed() = runTest {
+        val verKeyStr = "z6LSci5EK4Ezue5QA72ZX71QUbXY2xr5ygRw7wM1WJigTNnd"
+        val serviceStr = "eyJpZCI6IkRJRENvbW1WMiIsInQiOiJkbSIsInMiOiJsb2NhbGhvc3Q6ODA4MiIsInIiOltdLCJhIjpbImRtIl19"
+        val didString = "did:peer:2.E$verKeyStr.V$verKeyStr.S$serviceStr"
+
+        val castor = CastorImpl(ApolloMock())
+
+        val did = DIDParser.parse(didString)
+
+        assertFailsWith<CastorError.InvalidPeerDIDError> {
+            castor.verifySignature(did, "".encodeToByteArray(), "".encodeToByteArray())
+        }
+    }
+}

castor/src/jsMain/kotlin/CastorImplJs.kt

@@ -1,4 +1,5 @@
 import io.iohk.atala.prism.castor.CastorImpl
+import io.iohk.atala.prism.domain.models.DID
 import io.iohk.atala.prism.domain.models.DIDDocument
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.promise
@@ -12,4 +13,11 @@ class CastorImplJs : CastorImpl() {
     fun resolveDIDJS(did: String): Promise<DIDDocument> {
         return GlobalScope.promise { resolveDID(did) }
     }
+
+    @JsName("verifySignature")
+    fun verifySignatureJS(did: DID, challenge: ByteArray, signature: ByteArray): Promise<Boolean> {
+        return GlobalScope.promise {
+            verifySignature(did, challenge, signature)
+        }
+    }
 }

domain/src/commonMain/kotlin/io.iohk.atala.prism.domain/models/DIDDocument.kt

@@ -34,7 +34,26 @@ data class DIDDocument(
         val type: String,
         val publicKeyJwk: Map<String, String>? = null,
         val publicKeyMultibase: String? = null
-    )
+    ) {
+        companion object {
+            fun getCurveByType(type: String): Curve {
+                return when (type) {
+                    Curve.X25519.value -> {
+                        Curve.X25519
+                    }
+                    Curve.ED25519.value -> {
+                        Curve.ED25519
+                    }
+                    Curve.SECP256K1.value -> {
+                        Curve.SECP256K1
+                    }
+                    else -> {
+                        throw CastorError.InvalidKeyError()
+                    }
+                }
+            }
+        }
+    }
 
     @Serializable
     data class Service(