From 49654b7c82d104f7898eff95f0ac3cec96fbc0ec Mon Sep 17 00:00:00 2001
From: Craig Raw <craigraw@gmail.com>
Date: Thu, 1 Apr 2021 09:51:43 +0200
Subject: [PATCH] ensure safe psbt testing

---
 .../java/com/sparrowwallet/drongo/psbt/PSBT.java   | 14 ++++++++++----
 .../com/sparrowwallet/drongo/psbt/PSBTTest.java    |  8 ++++++++
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/src/main/java/com/sparrowwallet/drongo/psbt/PSBT.java b/src/main/java/com/sparrowwallet/drongo/psbt/PSBT.java
index 32d6c47..125e8a2 100644
--- a/src/main/java/com/sparrowwallet/drongo/psbt/PSBT.java
+++ b/src/main/java/com/sparrowwallet/drongo/psbt/PSBT.java
@@ -600,11 +600,17 @@ public class PSBT {
     }
 
     public static boolean isPSBT(String s) {
-        if (Utils.isHex(s) && s.startsWith(PSBT_MAGIC_HEX)) {
-            return true;
-        } else {
-            return Utils.isBase64(s) && Utils.bytesToHex(Base64.decode(s)).startsWith(PSBT_MAGIC_HEX);
+        try {
+            if(Utils.isHex(s) && s.startsWith(PSBT_MAGIC_HEX)) {
+                return true;
+            } else {
+                return Utils.isBase64(s) && Utils.bytesToHex(Base64.decode(s)).startsWith(PSBT_MAGIC_HEX);
+            }
+        } catch(Exception e) {
+            //ignore
         }
+
+        return false;
     }
 
     public static PSBT fromString(String strPSBT) throws PSBTParseException {
diff --git a/src/test/java/com/sparrowwallet/drongo/psbt/PSBTTest.java b/src/test/java/com/sparrowwallet/drongo/psbt/PSBTTest.java
index bb77ecc..1d41e8b 100644
--- a/src/test/java/com/sparrowwallet/drongo/psbt/PSBTTest.java
+++ b/src/test/java/com/sparrowwallet/drongo/psbt/PSBTTest.java
@@ -376,6 +376,14 @@ public class PSBTTest {
         Assert.assertEquals("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", Utils.bytesToHex(transaction.bitcoinSerialize()));
     }
 
+    @Test
+    public void isPSBT() {
+        String s = null;
+        Assert.assertFalse(PSBT.isPSBT(s));
+        Assert.assertFalse(PSBT.isPSBT(""));
+        Assert.assertFalse(PSBT.isPSBT("x"));
+    }
+
     @After
     public void tearDown() throws Exception {
         Network.set(null);