Merge pull request bitcoinjs#1039 from bitcoinjs/maybedec

decompile should return Maybe chunks

Author: dcousens

src/script.js

@@ -98,11 +98,11 @@ function decompile (buffer) {
       var d = pushdata.decode(buffer, i)
 
       // did reading a pushDataInt fail? empty script
-      if (d === null) return []
+      if (d === null) return null
       i += d.size
 
       // attempt to read too much data? empty script
-      if (i + d.number > buffer.length) return []
+      if (i + d.number > buffer.length) return null
 
       var data = buffer.slice(i, i + d.number)
       i += d.number

src/templates/index.js

@@ -28,6 +28,8 @@ function classifyOutput (script) {
 
   // XXX: optimization, below functions .decompile before use
   var chunks = decompile(script)
+  if (!chunks) throw new TypeError('Invalid script')
+
   if (multisig.output.check(chunks)) return types.MULTISIG
   if (pubKey.output.check(chunks)) return types.P2PK
   if (witnessCommitment.output.check(chunks)) return types.WITNESS_COMMITMENT
@@ -39,6 +41,7 @@ function classifyOutput (script) {
 function classifyInput (script, allowIncomplete) {
   // XXX: optimization, below functions .decompile before use
   var chunks = decompile(script)
+  if (!chunks) throw new TypeError('Invalid script')
 
   if (pubKeyHash.input.check(chunks)) return types.P2PKH
   if (scriptHash.input.check(chunks, allowIncomplete)) return types.P2SH
@@ -51,6 +54,7 @@ function classifyInput (script, allowIncomplete) {
 function classifyWitness (script, allowIncomplete) {
   // XXX: optimization, below functions .decompile before use
   var chunks = decompile(script)
+  if (!chunks) throw new TypeError('Invalid script')
 
   if (witnessPubKeyHash.input.check(chunks)) return types.P2WPKH
   if (witnessScriptHash.input.check(chunks, allowIncomplete)) return types.P2WSH

src/templates/scripthash/input.js

@@ -21,7 +21,7 @@ function check (script, allowIncomplete) {
   var redeemScriptChunks = bscript.decompile(lastChunk)
 
   // is redeemScript a valid script?
-  if (redeemScriptChunks.length === 0) return false
+  if (!redeemScriptChunks) return false
 
   // is redeemScriptSig push only?
   if (!bscript.isPushOnly(scriptSigChunks)) return false

src/transaction_builder.js

@@ -71,7 +71,7 @@ function expandInput (scriptSig, witnessStack) {
   var witnessProgram
   var chunks
 
-  var scriptSigChunks = bscript.decompile(scriptSig)
+  var scriptSigChunks = bscript.decompile(scriptSig) || []
   var sigType = btemplates.classifyInput(scriptSigChunks, true)
   if (sigType === scriptTypes.P2SH) {
     p2sh = true
@@ -209,7 +209,7 @@ function fixMultisigOrder (input, transaction, vin) {
 function expandOutput (script, scriptType, ourPubKey) {
   typeforce(types.Buffer, script)
 
-  var scriptChunks = bscript.decompile(script)
+  var scriptChunks = bscript.decompile(script) || []
   if (!scriptType) {
     scriptType = btemplates.classifyOutput(script)
   }
@@ -257,17 +257,19 @@ function checkP2SHInput (input, redeemScriptHash) {
   if (input.prevOutType) {
     if (input.prevOutType !== scriptTypes.P2SH) throw new Error('PrevOutScript must be P2SH')
 
-    var prevOutScriptScriptHash = bscript.decompile(input.prevOutScript)[1]
-    if (!prevOutScriptScriptHash.equals(redeemScriptHash)) throw new Error('Inconsistent hash160(redeemScript)')
+    var chunks = bscript.decompile(input.prevOutScript)
+    if (!chunks) throw new Error('Invalid prevOutScript')
+    if (!chunks[1].equals(redeemScriptHash)) throw new Error('Inconsistent hash160(redeemScript)')
   }
 }
 
 function checkP2WSHInput (input, witnessScriptHash) {
   if (input.prevOutType) {
     if (input.prevOutType !== scriptTypes.P2WSH) throw new Error('PrevOutScript must be P2WSH')
 
-    var scriptHash = bscript.decompile(input.prevOutScript)[1]
-    if (!scriptHash.equals(witnessScriptHash)) throw new Error('Inconsistent sha256(witnessScript)')
+    var chunks = bscript.decompile(input.prevOutScript)
+    if (!chunks) throw new Error('Invalid witnessScript')
+    if (!chunks[1].equals(witnessScriptHash)) throw new Error('Inconsistent sha256(witnessScript)')
   }
 }
 

test/fixtures/transaction_builder.json

@@ -1917,10 +1917,16 @@
           }
         ]
       },
+      {
+        "description": "Transaction w/ invalid scripts",
+        "exception": "Invalid script",
+        "incomplete": true,
+        "txHex": "010000000100000000171a0000e028f2000000000050178500000000000d0000000e000000000000002009f691b2263260e71f363d1db51ff3100d285956a40cc0e4f8c8c2c4a80559b1ffffffff0110270000000000001976a914aa4d7985c57e011a8b3dd8e0e5a73aaef41629c588ac00000000"
+      },
       {
         "description": "Complete transaction w/ non-standard inputs",
         "exception": "nonstandard not supported",
-        "txHex": "010000000100000000171a0000e028f2000000000050178500000000000d0000000e000000000000002009f691b2263260e71f363d1db51ff3100d285956a40cc0e4f8c8c2c4a80559b1ffffffff0110270000000000001976a914aa4d7985c57e011a8b3dd8e0e5a73aaef41629c588ac00000000"
+        "txHex": "010000000100000000171a0000e028f2000000000050178500000000000d0000000e00000000000000201ff691b2263260e71f363d1db51ff3100d285956a40cc0e4f8c8c2c4a80559b1ffffffff0110270000000000001976a914aa4d7985c57e011a8b3dd8e0e5a73aaef41629c588ac00000000"
       }
     ],
     "sign": [

test/script.js

@@ -124,10 +124,10 @@ describe('script', function () {
     })
 
     fixtures.invalid.decompile.forEach(function (f) {
-      it('decompiles ' + f.script + ' to [] because of "' + f.description + '"', function () {
+      it('fails to decompile ' + f.script + ',  because "' + f.description + '"', function () {
         var chunks = bscript.decompile(Buffer.from(f.script, 'hex'))
 
-        assert.strictEqual(chunks.length, 0)
+        assert.strictEqual(chunks, null)
       })
     })
   })