From f425f8b66b8c421b83621d3c2fc941333213a855 Mon Sep 17 00:00:00 2001
From: Francois Beutin <francois.beutin@ledger.fr>
Date: Thu, 10 Oct 2024 18:16:29 +0200
Subject: [PATCH] Fix swap implementation

---
 app/src/apdu_handler.c                 | 11 +++++++++++
 app/src/swap/handle_sign_transaction.c |  6 ++++--
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/app/src/apdu_handler.c b/app/src/apdu_handler.c
index a3804a2c..f25a8caf 100644
--- a/app/src/apdu_handler.c
+++ b/app/src/apdu_handler.c
@@ -179,6 +179,17 @@ __Z_INLINE void handleSign(volatile uint32_t *flags, volatile uint32_t *tx, uint
         THROW(APDU_CODE_DATA_INVALID);
     }
 
+#ifdef HAVE_SWAP
+    if (G_swap_state.called_from_swap && G_swap_state.should_exit && error_msg == NULL) {
+        // Call app_sign_ed25519 without going through UI display, the UI validation was done in
+        // Exchange app already
+        app_sign_ed25519();
+        // Go back to Exchange and report our success to display the modal
+        finalize_exchange_sign_transaction(true);
+        // Unreachable
+    }
+#endif
+
     view_review_init(tx_getItem, tx_getNumItems, app_sign_ed25519);
     view_review_show(REVIEW_TXN);
     *flags |= IO_ASYNCH_REPLY;
diff --git a/app/src/swap/handle_sign_transaction.c b/app/src/swap/handle_sign_transaction.c
index 00eeee44..9ce139b6 100644
--- a/app/src/swap/handle_sign_transaction.c
+++ b/app/src/swap/handle_sign_transaction.c
@@ -75,6 +75,7 @@ bool copy_transaction_parameters(create_transaction_parameters_t *sign_transacti
     return true;
 }
 
+// Ensure the received transaction matches what was validated in the Exchange app UI
 parser_error_t check_swap_conditions(parser_tx_t *txObj) {
     parser_error_t err = parser_unexpected_error;
     if (txObj == NULL) {
@@ -103,6 +104,7 @@ parser_error_t check_swap_conditions(parser_tx_t *txObj) {
     CHECK_ERROR(parser_getItem(txObj, &uiFields));
     if (strncmp(valid_network, tmpValue, strlen(valid_network)) != 0) {
         ZEMU_LOGF(200, "Swap not enable on %s network.\n", tmpValue);
+        return parser_swap_tx_wrong_method;
     }
 
     // Check method.
@@ -150,12 +152,12 @@ parser_error_t check_swap_conditions(parser_tx_t *txObj) {
     const size_t strLen = strlen(tmpValue);
     const size_t amountLen = strlen(tmpAmount);
     if (zxerr != zxerr_ok || strLen != amountLen || strncmp(tmpValue, tmpAmount, strLen) != 0) {
-        ZEMU_LOGF(200, "Wrong swap tx amount (%s, should be : %s).\n", tmp_str, tmpAmount);
+        ZEMU_LOGF(200, "Wrong swap tx amount (%s, should be : %s).\n", tmpValue, tmpAmount);
         return parser_swap_tx_wrong_amount;
     }
 
     ZEMU_LOGF(50, "Swap parameters verified by current tx\n");
-    return err;
+    return parser_ok;
 }
 
 void __attribute__((noreturn)) finalize_exchange_sign_transaction(bool is_success) {