fix: Added JWK object into payload body

modules/local-kms/src/commonMain/kotlin/com/sphereon/oid/fed/kms/local/LocalKms.kt

@@ -2,12 +2,11 @@ package com.sphereon.oid.fed.kms.local
 
 import com.sphereon.oid.fed.kms.local.database.LocalKmsDatabase
 import com.sphereon.oid.fed.kms.local.jwk.generateKeyPair
-import com.sphereon.oid.fed.openapi.models.JWTHeader
 import com.sphereon.oid.fed.kms.local.jwt.sign
 import com.sphereon.oid.fed.kms.local.jwt.verify
+import com.sphereon.oid.fed.openapi.models.JWTHeader
 import com.sphereon.oid.fed.openapi.models.Jwk
-import kotlinx.serialization.json.Json
-import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.*
 
 class LocalKms {
 
@@ -20,8 +19,30 @@ class LocalKms {
 
     fun sign(header: JWTHeader, payload: JsonObject, keyId: String): String {
         val jwk = database.getKey(keyId)
+        val jwkString: String = Json.decodeFromString(jwk.private_key)
+        val jwkObject: Jwk = Json.decodeFromString(jwkString)
+
+        // Adding necessary parameter is header
+        val mHeader = header.copy(alg = jwkObject.alg, kid = jwkObject.kid)
+
+        // Adding JWKs object in payload
+        val mutablePayload = payload.toMutableMap()
+        mutablePayload["kid"] = JsonPrimitive(jwkObject.kid)
+        val keyArrayOfJwks = buildJsonObject {
+            putJsonArray("keys") {
+                addJsonObject {
+                    put("kty", jwkObject.kty)
+                    put("n", jwkObject.n)
+                    put("e", jwkObject.e)
+                    put("kid", jwkObject.kid)
+                    put("use", jwkObject.use)
+                }
+            }
+        }
+        mutablePayload["jwks"] = keyArrayOfJwks
+        val mPayload = JsonObject(mutablePayload)
 
-        return sign(header = header, payload = payload, key = Json.decodeFromString(jwk.private_key))
+        return sign(header = mHeader, payload = mPayload, key = jwkObject)
     }
 
     fun verify(token: String, jwk: Jwk): Boolean {