Update and simplify default implementations.

src/main/kotlin/eu/europa/ec/eudi/openid4vp/Dispatcher.kt

@@ -15,6 +15,9 @@
  */
 package eu.europa.ec.eudi.openid4vp
 
+import eu.europa.ec.eudi.openid4vp.internal.dispatch.DefaultDispatcher
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.Dispatchers
 import java.io.Serializable
 import java.net.URI
 
@@ -72,4 +75,22 @@ fun interface Dispatcher {
      * method returns an appropriate [redirect_uri][DispatchOutcome.RedirectURI]
      */
     suspend fun dispatch(response: AuthorizationResponse): DispatchOutcome
+
+    companion object {
+
+        /**
+         * Factory method to create a [Dispatcher].
+         *
+         * @param ioCoroutineDispatcher the coroutine dispatcher to handle IO
+         * @param httpClientFactory a factory to obtain a Ktor http client
+         * @return a [Dispatcher]
+         *
+         * @see DefaultDispatcher
+         */
+        fun make(
+            ioCoroutineDispatcher: CoroutineDispatcher = Dispatchers.IO,
+            httpClientFactory: KtorHttpClientFactory = DefaultHttpClientFactory,
+        ): Dispatcher =
+            DefaultDispatcher(ioCoroutineDispatcher, httpClientFactory)
+    }
 }

src/main/kotlin/eu/europa/ec/eudi/openid4vp/Ktor.kt

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2023 European Commission
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package eu.europa.ec.eudi.openid4vp
+
+import io.ktor.client.*
+import io.ktor.client.plugins.contentnegotiation.*
+import io.ktor.serialization.kotlinx.json.*
+
+/**
+ * Alias of a method that creates a [HttpClient]
+ */
+typealias KtorHttpClientFactory = () -> HttpClient
+
+/**
+ * Factory which produces a [Ktor Http client][HttpClient]
+ * The actual engine will be peeked up by whatever
+ * it is available in classpath
+ *
+ * @see [Ktor Client]("https://ktor.io/docs/client-dependencies.html#engine-dependency)
+ */
+val DefaultHttpClientFactory: KtorHttpClientFactory = {
+    HttpClient {
+        install(ContentNegotiation) { json() }
+        expectSuccess = true
+    }
+}

src/main/kotlin/eu/europa/ec/eudi/openid4vp/SiopOpenId4Vp.kt

@@ -15,6 +15,7 @@
  */
 package eu.europa.ec.eudi.openid4vp
 
+import eu.europa.ec.eudi.openid4vp.internal.DefaultSiopOpenId4Vp
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.Dispatchers
 
@@ -38,20 +39,41 @@ interface SiopOpenId4Vp : AuthorizationRequestResolver, AuthorizationResponseBui
     companion object {
 
         /**
-         * Factory method to create a [SiopOpenId4Vp] based
-         * on ktor
+         * Factory method to create a [SiopOpenId4Vp].
          *
          * @param ioCoroutineDispatcher the coroutine dispatcher to handle IO
          * @param walletOpenId4VPConfig wallet's configuration
          * @param httpClientFactory a factory to obtain a Ktor http client
          * @return a [SiopOpenId4Vp]
          *
-         * @see SiopOpenId4VpKtor
+         * @see DefaultSiopOpenId4Vp
          */
-        fun ktor(
+        fun make(
             walletOpenId4VPConfig: WalletOpenId4VPConfig,
             ioCoroutineDispatcher: CoroutineDispatcher = Dispatchers.IO,
-            httpClientFactory: KtorHttpClientFactory = SiopOpenId4VpKtor.DefaultFactory,
-        ): SiopOpenId4Vp = SiopOpenId4VpKtor(ioCoroutineDispatcher, walletOpenId4VPConfig, httpClientFactory)
+            httpClientFactory: KtorHttpClientFactory = DefaultHttpClientFactory,
+        ): SiopOpenId4Vp =
+            make(
+                AuthorizationRequestResolver.make(ioCoroutineDispatcher, httpClientFactory, walletOpenId4VPConfig),
+                Dispatcher.make(ioCoroutineDispatcher, httpClientFactory),
+                AuthorizationResponseBuilder.make(walletOpenId4VPConfig),
+            )
+
+        /**
+         * Factory method to create a [SiopOpenId4Vp].
+         *
+         * @param authorizationResolver the [AuthorizationRequestResolver] instance to use
+         * @param dispatcher the [Dispatcher] instance to use
+         * @param authorizationResponseBuilder the [AuthorizationResponseBuilder] instance to use
+         * @return a [SiopOpenId4Vp]
+         *
+         * @see DefaultSiopOpenId4Vp
+         */
+        fun make(
+            authorizationResolver: AuthorizationRequestResolver,
+            dispatcher: Dispatcher,
+            authorizationResponseBuilder: AuthorizationResponseBuilder,
+        ): SiopOpenId4Vp =
+            DefaultSiopOpenId4Vp(authorizationResolver, dispatcher, authorizationResponseBuilder)
     }
 }

src/main/kotlin/eu/europa/ec/eudi/openid4vp/internal/DefaultSiopOpenId4Vp.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2023 European Commission
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package eu.europa.ec.eudi.openid4vp.internal
+
+import eu.europa.ec.eudi.openid4vp.AuthorizationRequestResolver
+import eu.europa.ec.eudi.openid4vp.AuthorizationResponseBuilder
+import eu.europa.ec.eudi.openid4vp.Dispatcher
+import eu.europa.ec.eudi.openid4vp.SiopOpenId4Vp
+
+/**
+ * An implementation of [SiopOpenId4Vp].
+ *
+ */
+internal class DefaultSiopOpenId4Vp(
+    private val authorizationResolver: AuthorizationRequestResolver,
+    private val dispatcher: Dispatcher,
+    private val authorizationResponseBuilder: AuthorizationResponseBuilder,
+) : SiopOpenId4Vp,
+    AuthorizationRequestResolver by authorizationResolver,
+    Dispatcher by dispatcher,
+    AuthorizationResponseBuilder by authorizationResponseBuilder

src/main/kotlin/eu/europa/ec/eudi/openid4vp/internal/dispatch/DefaultDispatcher.kt

@@ -39,7 +39,7 @@ import java.net.URL
  */
 internal class DefaultDispatcher(
     private val ioCoroutineDispatcher: CoroutineDispatcher = Dispatchers.IO,
-    private val httpClientFactory: KtorHttpClientFactory,
+    private val httpClientFactory: KtorHttpClientFactory = DefaultHttpClientFactory,
 ) : Dispatcher {
     override suspend fun dispatch(response: AuthorizationResponse): DispatchOutcome =
         when (response) {

src/main/kotlin/eu/europa/ec/eudi/openid4vp/internal/request/ClientMetaDataResolver.kt

@@ -26,7 +26,7 @@ import java.net.URL
 
 internal class ClientMetaDataResolver(
     private val ioCoroutineDispatcher: CoroutineDispatcher = Dispatchers.IO,
-    private val httpClientFactory: KtorHttpClientFactory,
+    private val httpClientFactory: KtorHttpClientFactory = DefaultHttpClientFactory,
     walletOpenId4VPConfig: WalletOpenId4VPConfig,
 ) {
     private val clientMetadataValidator = ClientMetadataValidator(ioCoroutineDispatcher, walletOpenId4VPConfig)

src/main/kotlin/eu/europa/ec/eudi/openid4vp/internal/request/ClientMetadataValidator.kt

@@ -22,13 +22,14 @@ import com.nimbusds.jose.jwk.JWKSet
 import eu.europa.ec.eudi.openid4vp.*
 import eu.europa.ec.eudi.openid4vp.internal.success
 import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import java.io.IOException
 import java.net.URL
 import java.text.ParseException
 
 internal class ClientMetadataValidator(
-    private val ioCoroutineDispatcher: CoroutineDispatcher,
+    private val ioCoroutineDispatcher: CoroutineDispatcher = Dispatchers.IO,
     private val walletOpenId4VPConfig: WalletOpenId4VPConfig,
 ) {
 

src/main/kotlin/eu/europa/ec/eudi/openid4vp/internal/request/DefaultAuthorizationRequestResolver.kt

@@ -28,9 +28,9 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 
 internal class DefaultAuthorizationRequestResolver(
-    private val ioCoroutineDispatcher: CoroutineDispatcher,
+    private val ioCoroutineDispatcher: CoroutineDispatcher = Dispatchers.IO,
     private val walletOpenId4VPConfig: WalletOpenId4VPConfig,
-    private val httpClientFactory: KtorHttpClientFactory,
+    private val httpClientFactory: KtorHttpClientFactory = DefaultHttpClientFactory,
     private val validatedRequestObjectResolver: ValidatedRequestObjectResolver,
 ) : AuthorizationRequestResolver {
 

src/main/kotlin/eu/europa/ec/eudi/openid4vp/internal/request/JarJwtSignatureValidator.kt

@@ -35,6 +35,7 @@ import eu.europa.ec.eudi.openid4vp.SupportedClientIdScheme.IsoX509
 import eu.europa.ec.eudi.openid4vp.SupportedClientIdScheme.Preregistered
 import eu.europa.ec.eudi.openid4vp.internal.success
 import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import kotlinx.serialization.json.Json
 import kotlinx.serialization.json.JsonObject
@@ -50,7 +51,7 @@ import java.text.ParseException
  * @param walletOpenId4VPConfig wallet's configuration
  */
 internal class JarJwtSignatureValidator(
-    private val ioCoroutineDispatcher: CoroutineDispatcher,
+    private val ioCoroutineDispatcher: CoroutineDispatcher = Dispatchers.IO,
     private val walletOpenId4VPConfig: WalletOpenId4VPConfig,
 ) {
 

src/main/kotlin/eu/europa/ec/eudi/openid4vp/internal/request/PresentationDefinitionResolver.kt

@@ -32,7 +32,7 @@ import java.net.URL
  */
 internal class PresentationDefinitionResolver(
     private val ioCoroutineDispatcher: CoroutineDispatcher = Dispatchers.IO,
-    private val httpClientFactory: KtorHttpClientFactory,
+    private val httpClientFactory: KtorHttpClientFactory = DefaultHttpClientFactory,
 ) {
 
     /**

src/test/kotlin/eu/europa/ec/eudi/openid4vp/AuthorizationRequestResolverTest.kt

@@ -69,7 +69,7 @@ class AuthorizationRequestResolverTest {
         authorizationEncryptionEncValuesSupported = emptyList(),
     )
 
-    private val resolver = SiopOpenId4Vp.ktor(walletConfig)
+    private val resolver = SiopOpenId4Vp.make(walletConfig)
 
     private val clientMetadataJwksInline =
         """ {

src/test/kotlin/eu/europa/ec/eudi/openid4vp/AuthorizationResponseDispatcherTest.kt

@@ -19,6 +19,7 @@ import com.nimbusds.jose.jwk.JWKSet
 import com.nimbusds.jose.jwk.KeyUse
 import com.nimbusds.jose.jwk.gen.RSAKeyGenerator
 import com.nimbusds.oauth2.sdk.id.State
+import eu.europa.ec.eudi.openid4vp.internal.dispatch.DefaultDispatcher
 import eu.europa.ec.eudi.openid4vp.internal.request.ClientMetadataValidator
 import io.ktor.client.plugins.contentnegotiation.*
 import io.ktor.serialization.kotlinx.json.*
@@ -138,8 +139,11 @@ class AuthorizationResponseDispatcherTest {
                 }
             }
 
-            val dispatcher = SiopOpenId4VpKtor.dispatcher { managedHttpClient }
-            when (val response = AuthorizationResponseBuilder.make(walletConfig).build(siopAuthRequestObject, idTokenConsensus)) {
+            val dispatcher = DefaultDispatcher(httpClientFactory = { managedHttpClient })
+            when (
+                val response =
+                    AuthorizationResponseBuilder.make(walletConfig).build(siopAuthRequestObject, idTokenConsensus)
+            ) {
                 is AuthorizationResponse.DirectPost -> {
                     dispatcher.dispatch(response)
                 }

src/test/kotlin/eu/europa/ec/eudi/openid4vp/Example.kt

@@ -236,7 +236,7 @@ private class Wallet(
         get() = walletKeyPair.toPublicJWK()
 
     private val siopOpenId4Vp: SiopOpenId4Vp by lazy {
-        SiopOpenId4Vp.ktor(walletConfig) { createHttpClient() }
+        SiopOpenId4Vp.make(walletConfig) { createHttpClient() }
     }
 
     suspend fun handle(uri: URI): DispatchOutcome {