[#6] Out of band (standard) message encoding

tdiesler · Dec 21, 2022 · 7b8f28a · 7b8f28a
1 parent 1458cfe
commit 7b8f28a
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Showing 3 changed files with 75 additions and 21 deletions.
diff --git a/core/src/main/kotlin/org/nessus/didcomm/model/MessageWriter.kt b/core/src/main/kotlin/org/nessus/didcomm/model/MessageWriter.kt
@@ -3,6 +3,7 @@ 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
 
 /**
@@ -19,13 +20,27 @@ class MessageWriter {
             .setPrettyPrinting()
             .create()
 
+        fun toBase64URL(msg: Message): String {
+            return Base64URL.encode(toJson(msg)).toString()
+        }
+
         fun toJson(msg: Message, pretty: Boolean = false) : String {
-            return toJson(msg as Any, pretty)
+            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)
+            return auxGson(pretty).toJson(obj)
+        }
+
+        private fun auxGson(pretty: Boolean = false): Gson {
+            return if (pretty) prettyGson else gson
         }
     }
 }
diff --git a/core/src/test/kotlin/org/nessus/didcomm/test/model/Fixtures.kt b/core/src/test/kotlin/org/nessus/didcomm/test/model/Fixtures.kt
@@ -1,8 +1,6 @@
 package org.nessus.didcomm.test.model
 
-import org.didcommx.didcomm.message.Attachment
-import org.didcommx.didcomm.message.Message
-import org.nessus.didcomm.model.OutOfBandInvitationV2
+import org.nessus.didcomm.model.MessageParser
 
 class OutOfBand {
 
@@ -11,20 +9,50 @@ class OutOfBand {
         const val ALICE_DID = "did:example:alice"
         const val FABER_DID = "did:example:faber"
 
-        private const val ID = "1234567890"
-        private const val TYPE = OutOfBandInvitationV2.type
+        val FABER_OUT_OF_BAND_INVITATION = MessageParser.fromJson("""
+            {
+              "type": "https://didcomm.org/out-of-band/2.0/invitation",
+              "id": "1234567890",
+              "from": "did:example:faber",
+              "body": {
+                "goal_code": "issue-vc",
+                "goal": "To issue a Faber College Graduate credential",
+                "accept": [
+                  "didcomm/v2",
+                  "didcomm/aip2;env=rfc587"
+                ]
+              },
+              "attachments": [
+                {
+                    "id": "request-0",
+                    "media_type": "application/json",
+                    "data": {
+                        "json": {"protocol message": "content"}
+                    }
+                }
+              ]
+            }                
+        """.trimIndent())
 
-        val OUT_OF_BAND_INVITATION = Message.builder(ID, mapOf(
-            "goal_code" to "issue-vc",
-            "goal" to "To issue a Faber College Graduate credential",
-            "accept" to listOf("didcomm/v2", "didcomm/aip2;env=rfc587")),
-            TYPE)
-            .from(FABER_DID)
-            .createdTime(1516269022)
-            .expiresTime(1516385931)
-            .attachments(listOf(
-                Attachment.builder(
-                    "request-0", Attachment.Data.parse(mapOf("base64" to "qwerty"))).build()))
-            .build()
+        val ALICE_OUT_OF_BAND_INVITATION = MessageParser.fromJson("""
+            {
+              "type": "https://didcomm.org/out-of-band/2.0/invitation",
+              "id": "69212a3a-d068-4f9d-a2dd-4741bca89af3",
+              "from": "did:example:alice",
+              "body": {
+                  "goal_code": "",
+                  "goal": ""
+              },
+              "attachments": [
+                  {
+                      "id": "request-0",
+                      "media_type": "application/json",
+                      "data": {
+                          "base64": "qwerty"
+                      }
+                  }
+              ]
+            }        
+        """.trimIndent())
    }
 }
diff --git a/core/src/test/kotlin/org/nessus/didcomm/test/model/OutOfBandInvitationTest.kt b/core/src/test/kotlin/org/nessus/didcomm/test/model/OutOfBandInvitationTest.kt
@@ -17,7 +17,7 @@ class OutOfBandInvitationTest {
     @Test
     fun testOutOfBandInvitation() {
 
-        val exp: Message = OutOfBand.OUT_OF_BAND_INVITATION
+        val exp: Message = OutOfBand.FABER_OUT_OF_BAND_INVITATION
         val expBody = OutOfBandInvitationV2.fromBody(exp.body)
         val expJson: String = MessageWriter.toJson(exp)
         log.info("exp: {}", expJson)
@@ -31,4 +31,15 @@ class OutOfBandInvitationTest {
         assertEquals(expBody, wasBody)
     }
 
+    @Test
+    fun testOutOfBandEncoding() {
+        val exp: Message = OutOfBand.ALICE_OUT_OF_BAND_INVITATION
+        val expJson: String = MessageWriter.toJson(exp)
+        log.info("exp: {}", expJson)
+
+        val base64URLEncoded = MessageWriter.toBase64URL(exp)
+        log.info("enc: {}", base64URLEncoded)
+        assertEquals("eyJpZCI6IjY5MjEy", base64URLEncoded.substring(0..15))
+
+    }
 }