From 65d983a5e7519113f2f7ec288593b660a16734ad Mon Sep 17 00:00:00 2001
From: dankito <git@dankito.net>
Date: Thu, 26 Sep 2024 14:20:12 +0200
Subject: [PATCH] Added a check to determine HHD version

---
 .../net/codinux/banking/fints/FinTsJobExecutor.kt      | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fints4k/src/commonMain/kotlin/net/codinux/banking/fints/FinTsJobExecutor.kt b/fints4k/src/commonMain/kotlin/net/codinux/banking/fints/FinTsJobExecutor.kt
index 7c134570..0cfb0f11 100644
--- a/fints4k/src/commonMain/kotlin/net/codinux/banking/fints/FinTsJobExecutor.kt
+++ b/fints4k/src/commonMain/kotlin/net/codinux/banking/fints/FinTsJobExecutor.kt
@@ -444,7 +444,7 @@ Log.info { "Terminating waiting for TAN input" } // TODO: remove again
         return when (tanMethod.type) {
             TanMethodType.ChipTanFlickercode ->
                 FlickerCodeTanChallenge(
-                    FlickerCodeDecoder().decodeChallenge(challenge, tanMethod.hhdVersion ?: HHDVersion.HHD_1_4), // HHD 1.4 is currently the most used version
+                    FlickerCodeDecoder().decodeChallenge(challenge, tanMethod.hhdVersion ?: getFallbackHhdVersion(challenge)),
                     forAction, messageToShowToUser, challenge, tanMethod, tanResponse.tanMediaIdentifier, bank, account, tanResponse.tanExpirationTime)
 
             TanMethodType.ChipTanQrCode, TanMethodType.ChipTanPhotoTanMatrixCode,
@@ -455,6 +455,14 @@ Log.info { "Terminating waiting for TAN input" } // TODO: remove again
         }
     }
 
+    protected open fun getFallbackHhdVersion(challenge: String): HHDVersion {
+        if (challenge.length <= 35) { // is this true in all circumstances?
+            return HHDVersion.HHD_1_3
+        }
+
+        return HHDVersion.HHD_1_4 // HHD 1.4 is currently the most used version
+    }
+
     protected open suspend fun mayRetrieveAutomaticallyIfUserEnteredDecoupledTan(context: JobContext, tanChallenge: TanChallenge, tanResponse: TanResponse) {
         context.bank.selectedTanMethod.decoupledParameters?.let { decoupledTanMethodParameters ->
             if (decoupledTanMethodParameters.periodicStateRequestsAllowed) {