From 9f760edd2575b45a6efbf0da7b1f66a5b1d2fb09 Mon Sep 17 00:00:00 2001
From: Alva Swanson <alvasw@protonmail.com>
Date: Tue, 9 Jan 2024 15:04:14 +0100
Subject: [PATCH] TxValidator: Fix fee check crash on invalid JSON response

The initialSanityChecks method only checks whether the JSON response is
null (HTTP request failed) or the response is empty (HTTP 200) before
parsing the JSON response. A invalid JSON response would throw a
JsonSyntaxException exception which the callers are not catching.
---
 .../bisq/core/provider/mempool/TxValidator.java    | 14 ++++++++++----
 .../bisq/core/fee/TxValidatorSanityCheckTests.java |  9 +++++++++
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/core/src/main/java/bisq/core/provider/mempool/TxValidator.java b/core/src/main/java/bisq/core/provider/mempool/TxValidator.java
index b5f34f35b23..479724f7db2 100644
--- a/core/src/main/java/bisq/core/provider/mempool/TxValidator.java
+++ b/core/src/main/java/bisq/core/provider/mempool/TxValidator.java
@@ -94,8 +94,9 @@ public TxValidator(DaoStateService daoStateService, String txId, FilterManager f
 
     public TxValidator parseJsonValidateMakerFeeTx(String jsonTxt, List<String> btcFeeReceivers) {
         this.jsonTxt = jsonTxt;
-        FeeValidationStatus status = initialSanityChecks(txId, jsonTxt);
+        FeeValidationStatus status;
         try {
+            status = initialSanityChecks(txId, jsonTxt);
             if (status.pass()) {
                 status = checkFeeAddressBTC(jsonTxt, btcFeeReceivers);
                 if (status.pass()) {
@@ -131,8 +132,9 @@ public TxValidator validateBsqFeeTx(boolean isMaker) {
 
     public TxValidator parseJsonValidateTakerFeeTx(String jsonTxt, List<String> btcFeeReceivers) {
         this.jsonTxt = jsonTxt;
-        FeeValidationStatus status = initialSanityChecks(txId, jsonTxt);
+        FeeValidationStatus status;
         try {
+            status = initialSanityChecks(txId, jsonTxt);
             if (status.pass()) {
                 status = checkFeeAddressBTC(jsonTxt, btcFeeReceivers);
                 if (status.pass()) {
@@ -148,10 +150,14 @@ public TxValidator parseJsonValidateTakerFeeTx(String jsonTxt, List<String> btcF
     }
 
     public long parseJsonValidateTx() {
-        if (!initialSanityChecks(txId, jsonTxt).pass()) {
+        try {
+            if (!initialSanityChecks(txId, jsonTxt).pass()) {
+                return -1;
+            }
+            return getTxConfirms(jsonTxt, chainHeight);
+        } catch (JsonSyntaxException e) {
             return -1;
         }
-        return getTxConfirms(jsonTxt, chainHeight);
     }
 
     ///////////////////////////////////////////////////////////////////////////////////////////
diff --git a/core/src/test/java/bisq/core/fee/TxValidatorSanityCheckTests.java b/core/src/test/java/bisq/core/fee/TxValidatorSanityCheckTests.java
index 4103061f211..a6ebd611de4 100644
--- a/core/src/test/java/bisq/core/fee/TxValidatorSanityCheckTests.java
+++ b/core/src/test/java/bisq/core/fee/TxValidatorSanityCheckTests.java
@@ -70,6 +70,15 @@ void nullAndEmptyMempoolResponse(String jsonText) {
         assertThat(status, is(equalTo(FeeValidationStatus.NACK_JSON_ERROR)));
     }
 
+    @Test
+    void invalidJsonResponse() {
+        String invalidJson = "in\"valid'json',";
+        TxValidator txValidator1 = txValidator.parseJsonValidateMakerFeeTx(invalidJson, FEE_RECEIVER_ADDRESSES);
+
+        FeeValidationStatus status = txValidator1.getStatus();
+        assertThat(status, is(equalTo(FeeValidationStatus.NACK_JSON_ERROR)));
+    }
+
     @ParameterizedTest
     @ValueSource(strings = {"status", "txid"})
     void mempoolResponseWithMissingField(String missingField) throws IOException {