[#6] Out of band didcomm message encoding

core/pom.xml

@@ -36,10 +36,6 @@
     <packaging>jar</packaging>
 
     <dependencies>
-        <dependency>
-            <groupId>org.jetbrains.kotlin</groupId>
-            <artifactId>kotlin-stdlib</artifactId>
-        </dependency>
         <dependency>
             <groupId>com.google.crypto.tink</groupId>
             <artifactId>tink</artifactId>

core/src/main/kotlin/org/nessus/didcomm/model/MessageReader.kt

@@ -0,0 +1,32 @@
+package org.nessus.didcomm.model
+
+import com.google.gson.Gson
+import org.didcommx.didcomm.message.Message
+
+/**
+ * Parses a JSON string to a DIDComm Message
+ */
+object MessageReader {
+
+    private val gson = Gson()
+
+    fun fromJson(json: String) : Message {
+        val jsonMap: MutableMap<String, Any> = mutableMapOf()
+        gson.fromJson(json, Map::class.java).forEach { en ->
+            val enval = en.value!!
+            when(val key: String = en.key.toString()) {
+                "created_time" -> jsonMap[key] = (enval as Double).toLong()
+                "expires_time" -> jsonMap[key] = (enval as Double).toLong()
+                "custom_headers" -> if (enval is Map<*, *> && enval.isNotEmpty()) {
+                    jsonMap[key] = enval
+                }
+                else -> jsonMap[key] = enval
+            }
+        }
+        return Message.parse(jsonMap)
+    }
+
+    fun <T> fromJson(json: String, type: Class<T>) : T {
+        return gson.fromJson(json, type)
+    }
+}

core/src/main/kotlin/org/nessus/didcomm/model/MessageType.kt

@@ -0,0 +1,14 @@
+package org.nessus.didcomm.model
+
+abstract class MessageType (
+
+    /**
+     * The header conveying the DIDComm Message Type URI.
+     * REQUIRED
+     */
+    val type: String
+) {
+    companion object {
+        const val OUT_OF_BAND_INVITATION = "https://didcomm.org/out-of-band/2.0/invitation"
+    }
+}

core/src/main/kotlin/org/nessus/didcomm/model/MessageWriter.kt

@@ -3,29 +3,51 @@ package org.nessus.didcomm.model
 import com.google.gson.FieldNamingPolicy
 import com.google.gson.Gson
 import com.google.gson.GsonBuilder
+import com.nimbusds.jose.util.Base64URL
 import org.didcommx.didcomm.message.Message
 
 /**
  * Serializes a DIDComm Message to JSON
  */
-class MessageWriter {
-
-    companion object {
-        private val gson: Gson = GsonBuilder()
-            .setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES)
-            .create()
-        private val prettyGson: Gson = GsonBuilder()
-            .setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES)
-            .setPrettyPrinting()
-            .create()
-
-        fun toJson(msg: Message, pretty: Boolean = false) : String {
-            return toJson(msg as Any, pretty)
+object MessageWriter {
+
+    private val gson: Gson = GsonBuilder()
+        .setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES)
+        .create()
+    private val prettyGson: Gson = GsonBuilder()
+        .setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES)
+        .setPrettyPrinting()
+        .create()
+
+    fun toBase64URL(msg: Message): String {
+        return Base64URL.encode(toJson(msg)).toString()
+    }
+
+    fun toJson(msg: Message, pretty: Boolean = false) : String {
+        val jsonObj = gson.toJsonTree(msg).asJsonObject
+        // Remove empty 'custom_headers'
+        // [TODO] we may have to remove emtpty content for other headers too
+        val customHeaders = jsonObj.getAsJsonObject("custom_headers")
+        if (customHeaders.entrySet().isEmpty()) {
+            jsonObj.remove("custom_headers")
         }
+        return auxGson(pretty).toJson(jsonObj)
+    }
 
-        fun toJson(obj: Any, pretty: Boolean = false) : String {
-            val gson = if (pretty) prettyGson else gson
-            return gson.toJson(obj)
+    fun toJson(obj: Any, pretty: Boolean = false) : String {
+        return auxGson(pretty).toJson(obj)
+    }
+
+    fun toMutableMap(obj: Any) : MutableMap<String, Any> {
+        val result: MutableMap<String, Any> = mutableMapOf()
+        val input: String = if (obj is String) obj else gson.toJson(obj)
+        gson.fromJson(input, MutableMap::class.java).forEach {
+                en -> result[en.key as String] = en.value!!
         }
+        return result
+    }
+
+    private fun auxGson(pretty: Boolean = false): Gson {
+        return if (pretty) prettyGson else gson
     }
 }

core/src/main/kotlin/org/nessus/didcomm/model/OutOfBandInvitationV2.kt → core/src/main/kotlin/org/nessus/didcomm/model/OutOfBandInvitation.kt

@@ -28,7 +28,7 @@ import com.google.gson.Gson
  *   ]
  * }
  */
-data class OutOfBandInvitationV2(
+data class OutOfBandInvitation(
 
     /**
      * Message ID. The id attribute value MUST be unique to the sender, across all messages they send.
@@ -69,19 +69,12 @@ data class OutOfBandInvitationV2(
      * OPTIONAL
      */
     val attachments: List<Any>?,
-) {
+) : MessageType(OUT_OF_BAND_INVITATION) {
 
     companion object {
-
-        /**
-         * The header conveying the DIDComm MTURI.
-         * REQUIRED
-         */
-        const val type: String = "https://didcomm.org/out-of-band/2.0/invitation"
-
-        fun fromBody(body: Map<String, Any?>): OutOfBandInvitationV2 {
+        fun fromBody(body: Map<String, Any?>): OutOfBandInvitation {
             val gson = Gson()
-            return gson.fromJson(gson.toJson(body), OutOfBandInvitationV2::class.java)
+            return gson.fromJson(gson.toJson(body), OutOfBandInvitation::class.java)
         }
     }
 }

core/src/main/kotlin/org/nessus/didcomm/service/AgentService.kt

@@ -0,0 +1,19 @@
+package org.nessus.didcomm.service
+
+import org.didcommx.didcomm.message.Message
+import org.nessus.didcomm.wallet.NessusWallet
+
+/**
+ * An Agent can create, send, receive DIDComMessages
+ */
+interface AgentService : Service {
+
+    companion object {
+        val type: Class<AgentService> = AgentService::class.java
+    }
+
+    override val type: Class<AgentService>
+        get() = Companion.type
+
+    fun createMessage(wallet: NessusWallet, type: String, body: Map<String, Any> = mapOf()) : Message
+}

core/src/main/kotlin/org/nessus/didcomm/service/ServiceRegistry.kt

@@ -0,0 +1,20 @@
+package org.nessus.didcomm.service
+
+// [TODO] document all services
+interface Service {
+    val type: Class<out Service>
+}
+
+// [TODO] document ServiceRegistry
+object ServiceRegistry {
+
+    private val registry : MutableMap<String, Service> = mutableMapOf()
+
+    fun <T : Service> getService(type : Class<T>) : T {
+        return registry[type.name] as T
+    }
+
+    fun <T : Service> addService(service: T) {
+        registry[service.type.name] = service
+    }
+}

core/src/main/kotlin/org/nessus/didcomm/service/WalletService.kt

@@ -0,0 +1,34 @@
+package org.nessus.didcomm.service
+
+import org.nessus.didcomm.wallet.NessusWallet
+import org.nessus.didcomm.wallet.WalletException
+import org.nessus.didcomm.wallet.WalletRegistry
+
+interface WalletService : Service {
+
+    companion object {
+        val type: Class<WalletService> = WalletService::class.java
+        val registry = WalletRegistry()
+    }
+
+    override val type: Class<WalletService>
+        get() = Companion.type
+
+    fun assertConfigValue(config: Map<String, Any?>, key: String) : Any {
+        return config[key] ?: throw WalletException("No config value for: $key")
+    }
+
+    fun getConfigValue(config: Map<String, Any?>, key: String) : Any? {
+        return config[key]
+    }
+
+    fun hasConfigValue(config: Map<String, Any?>, key: String) : Boolean {
+        return config[key] != null
+    }
+
+    fun createWallet(config: Map<String, Any?>): NessusWallet
+
+    fun publicDid(wallet: NessusWallet): String?
+
+    fun closeAndRemove(wallet: NessusWallet?)
+}

core/src/main/kotlin/org/nessus/didcomm/wallet/Did.kt

@@ -4,7 +4,7 @@ import id.walt.crypto.KeyAlgorithm
 
 val DEFAULT_KEY_ALGORITHM = KeyAlgorithm.EdDSA_Ed25519
 
-enum class DidMethod(mname : String) {
+enum class DidMethod(val mname : String) {
     KEY("key"),
     SOV("sov");
 
@@ -13,11 +13,11 @@ enum class DidMethod(mname : String) {
     }
 }
 
-open class Did(method: DidMethod) {
-}
-
-class DidKey() : Did(DidMethod.KEY) {
-}
-
-class DidSov() : Did(DidMethod.SOV) {
-}
+//open class Did(method: DidMethod) {
+//}
+//
+//class DidKey() : Did(DidMethod.KEY) {
+//}
+//
+//class DidSov() : Did(DidMethod.SOV) {
+//}