From a535d7d4149ef4bd584ad8d312e79ef646ce4a1f Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Wed, 22 Feb 2017 12:40:05 -0800
Subject: [PATCH] tx: fix witness item check.

---
 lib/primitives/tx.js | 107 ++++++++++++++++++++++---------------------
 1 file changed, 56 insertions(+), 51 deletions(-)

diff --git a/lib/primitives/tx.js b/lib/primitives/tx.js
index a8063097..082cccd9 100644
--- a/lib/primitives/tx.js
+++ b/lib/primitives/tx.js
@@ -1559,7 +1559,7 @@ TX.prototype.hasStandardInputs = function hasStandardInputs(view) {
  */
 
 TX.prototype.hasStandardWitness = function hasStandardWitness(view) {
-  var i, j, input, witness, coin, prev, redeem, m, n;
+  var i, j, input, witness, coin, prev, redeem, m;
 
   if (this.isCoinbase())
     return true;
@@ -1599,65 +1599,70 @@ TX.prototype.hasStandardWitness = function hasStandardWitness(view) {
       continue;
     }
 
-    if (!prev.isWitnessScripthash()) {
-      // Unknown program type,
-      // let it through for now.
+    if (prev.isWitnessScripthash()) {
+      if (witness.items.length - 1 > policy.MAX_P2WSH_STACK)
+        return false;
+
+      for (j = 0; j < witness.items.length - 1; j++) {
+        if (witness.items[j].length > policy.MAX_P2WSH_PUSH)
+          return false;
+      }
+
+      redeem = witness.items[witness.items.length - 1];
+
+      if (redeem.length > policy.MAX_P2WSH_SIZE)
+        return false;
+
+      prev = new Script(redeem);
+
+      if (prev.isPubkey()) {
+        if (witness.items.length - 1 !== 1)
+          return false;
+
+        if (witness.items[0].length > 73)
+          return false;
+
+        continue;
+      }
+
+      if (prev.isPubkeyhash()) {
+        if (input.witness.length - 1 !== 2)
+          return false;
+
+        if (witness.items[0].length > 73)
+          return false;
+
+        if (witness.items[1].length > 65)
+          return false;
+
+        continue;
+      }
+
+      if (prev.isMultisig()) {
+        m = prev.getSmall(0);
+
+        if (witness.items.length - 1 !== m + 1)
+          return false;
+
+        if (witness.items[0].length !== 0)
+          return false;
+
+        for (j = 1; j < witness.items.length - 1; j++) {
+          if (witness.items[j].length > 73)
+            return false;
+        }
+      }
+
       continue;
     }
 
-    redeem = witness.items[witness.items.length - 1];
-
-    if (redeem.length > policy.MAX_P2WSH_SIZE)
-      return false;
-
-    if (witness.items.length - 1 > policy.MAX_P2WSH_STACK)
+    if (witness.items.length > policy.MAX_P2WSH_STACK)
       return false;
 
     for (j = 0; j < witness.items.length; j++) {
       if (witness.items[j].length > policy.MAX_P2WSH_PUSH)
         return false;
     }
-
-    prev = new Script(redeem);
-
-    if (prev.isPubkey()) {
-      if (witness.items.length - 1 !== 1)
-        return false;
-
-      if (witness.items[0].length > 73)
-        return false;
-
-      continue;
-    }
-
-    if (prev.isPubkeyhash()) {
-      if (input.witness.length - 1 !== 2)
-        return false;
-
-      if (witness.items[0].length > 73)
-        return false;
-
-      if (witness.items[1].length > 65)
-        return false;
-
-      continue;
-    }
-
-    if (prev.isMultisig()) {
-      m = prev.getSmall(0);
-      n = prev.getSmall(prev.length - 2);
-
-      if (witness.items.length - 1 !== m + 1)
-        return false;
-
-      if (witness.items[0].length !== 0)
-        return false;
-
-      for (j = 1; j < witness.items.length - 1; j++) {
-        if (witness.items[j].length > 73)
-          return false;
-      }
-    }
   }
 
   return true;