Return sector 3 payload blocks in card prepare

src/main/kotlin/com/android/trisolarisserver/controller/IssuedCards.kt

@@ -74,9 +74,9 @@ class IssuedCards(
             timeData = payload.timeData,
             issuedAt = issuedAt.toString(),
             expiresAt = expiresAt.toString(),
-            issuerUserId = actor.id,
-            issuerFirebaseUid = actor.firebaseUid,
-            issuerName = actor.name
+            sector3Block0 = encodeBlock(actor.name),
+            sector3Block1 = encodeBlock(actor.id?.toString()),
+            sector3Block2 = encodeBlock(null)
         )
     }
 
@@ -183,6 +183,16 @@ class IssuedCards(
         return OffsetDateTime.now(zone)
     }
 
+    private fun encodeBlock(value: String?): String {
+        val raw = (value ?: "").padEnd(16).take(16)
+        val bytes = raw.toByteArray(Charsets.UTF_8)
+        val sb = StringBuilder(bytes.size * 2)
+        for (b in bytes) {
+            sb.append(String.format("%02X", b))
+        }
+        return sb.toString()
+    }
+
     private fun requireMember(propertyId: UUID, principal: MyPrincipal?) {
         if (principal == null) {
             throw ResponseStatusException(HttpStatus.UNAUTHORIZED, "Missing principal")