TxValidator: Fix crash on missing vin[0].prevout

The `checkFeeAmountBTC` method looks up the `value` field of the `vin[0].prevout` field without checking whether `vin[0].prevout` exists. When the field is missing `JsonElement jsonVIn0Value = jsonVin0.getAsJsonObject("prevout").get("value");` (line 193) throws a NullPointerException.
bisq-network · Jan 15, 2024 · 516d3c8 · 516d3c8
1 parent ba09db4
commit 516d3c8
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Showing 3 changed files with 43 additions and 1 deletion.
diff --git a/core/src/main/java/bisq/core/provider/mempool/TxValidator.java b/core/src/main/java/bisq/core/provider/mempool/TxValidator.java
@@ -190,7 +190,13 @@ private FeeValidationStatus checkFeeAmountBTC(String jsonTxt, Coin tradeAmount,
         JsonArray jsonVout = getVinAndVout(jsonTxt).second;
         JsonObject jsonVin0 = jsonVin.get(0).getAsJsonObject();
         JsonObject jsonVout0 = jsonVout.get(0).getAsJsonObject();
-        JsonElement jsonVIn0Value = jsonVin0.getAsJsonObject("prevout").get("value");
+
+        JsonObject jsonVin0PreVout = jsonVin0.getAsJsonObject("prevout");
+        if (jsonVin0PreVout == null) {
+            throw new JsonSyntaxException("vin[0].prevout missing");
+        }
+
+        JsonElement jsonVIn0Value = jsonVin0PreVout.get("value");
         JsonElement jsonFeeValue = jsonVout0.get("value");
         if (jsonVIn0Value == null || jsonFeeValue == null) {
             throw new JsonSyntaxException("vin/vout missing data");

diff --git a/core/src/test/java/bisq/core/fee/MakerTxValidatorSanityCheckTests.java b/core/src/test/java/bisq/core/fee/MakerTxValidatorSanityCheckTests.java
@@ -154,6 +154,24 @@ void checkFeeAddressBtcNoTooFewVout(int numberOfVouts) throws IOException {
         assertThat(txValidator1.getStatus(), is(FeeValidationStatus.NACK_JSON_ERROR));
     }
 
+    @Test
+    void checkFeeAmountMissingVinPreVout() throws IOException {
+        JsonObject json = MakerTxValidatorSanityCheckTests.getValidBtcMakerFeeMempoolJsonResponse();
+        JsonObject firstInput = json.get("vin").getAsJsonArray().get(0).getAsJsonObject();
+        firstInput.remove("prevout");
+
+        boolean hasPreVout = json.get("vin").getAsJsonArray()
+                .get(0).getAsJsonObject()
+                .has("prevout");
+        assertThat(hasPreVout, is(false));
+
+        String jsonContent = new Gson().toJson(json);
+        TxValidator txValidator1 = txValidator.parseJsonValidateMakerFeeTx(jsonContent,
+                MakerTxValidatorSanityCheckTests.FEE_RECEIVER_ADDRESSES);
+
+        assertThat(txValidator1.getStatus(), is(FeeValidationStatus.NACK_JSON_ERROR));
+    }
+
     @Test
     void responseHasDifferentTxId() throws IOException {
         String differentTxId = "abcde971ead7d03619e3a9eeaa771ed5adba14c448839e0299f857f7bb4ec07";

diff --git a/core/src/test/java/bisq/core/fee/TakerTxValidatorSanityCheckTests.java b/core/src/test/java/bisq/core/fee/TakerTxValidatorSanityCheckTests.java
@@ -154,6 +154,24 @@ void checkFeeAddressBtcNoTooFewVout(int numberOfVouts) throws IOException {
         assertThat(txValidator1.getStatus(), is(FeeValidationStatus.NACK_JSON_ERROR));
     }
 
+    @Test
+    void checkFeeAmountMissingVinPreVout() throws IOException {
+        JsonObject json = MakerTxValidatorSanityCheckTests.getValidBtcMakerFeeMempoolJsonResponse();
+        JsonObject firstInput = json.get("vin").getAsJsonArray().get(0).getAsJsonObject();
+        firstInput.remove("prevout");
+
+        boolean hasPreVout = json.get("vin").getAsJsonArray()
+                .get(0).getAsJsonObject()
+                .has("prevout");
+        assertThat(hasPreVout, is(false));
+
+        String jsonContent = new Gson().toJson(json);
+        TxValidator txValidator1 = txValidator.parseJsonValidateMakerFeeTx(jsonContent,
+                MakerTxValidatorSanityCheckTests.FEE_RECEIVER_ADDRESSES);
+
+        assertThat(txValidator1.getStatus(), is(FeeValidationStatus.NACK_JSON_ERROR));
+    }
+
     @Test
     void responseHasDifferentTxId() throws IOException {
         String differentTxId = "abcde971ead7d03619e3a9eeaa771ed5adba14c448839e0299f857f7bb4ec07";