witnessScriptHash: fixed implementation

Author: dcousens

src/templates/witnessscripthash/input.js

@@ -1,9 +1,63 @@
-// {signature} {pubKey}
+// <scriptSig> {serialized scriptPubKey script}
 
-var p2sh = require('../scripthash/input')
+var bscript = require('../../script')
+var types = require('../../types')
+var typeforce = require('typeforce')
+
+var p2ms = require('../multisig/')
+var p2pk = require('../pubkey/')
+var p2pkh = require('../pubkeyhash/')
+
+function check (chunks, allowIncomplete) {
+  typeforce(types.Array, chunks)
+  if (chunks.length < 1) return false
+
+  var witnessScript = chunks[chunks.length - 1]
+  if (!Buffer.isBuffer(witnessScript)) return false
+
+  var witnessScriptChunks = bscript.decompile(witnessScript)
+
+  // is witnessScript a valid script?
+  if (witnessScriptChunks.length === 0) return false
+
+  var witnessRawScriptSig = bscript.compile(chunks.slice(0, -1))
+
+  // match types
+  if (p2pkh.input.check(witnessRawScriptSig) &&
+    p2pkh.output.check(witnessScriptChunks)) return true
+
+  if (p2ms.input.check(witnessRawScriptSig, allowIncomplete) &&
+    p2ms.output.check(witnessScriptChunks)) return true
+
+  if (p2pk.input.check(witnessRawScriptSig) &&
+    p2pk.output.check(witnessScriptChunks)) return true
+
+  return false
+}
+check.toJSON = function () { return 'witnessScriptHash input' }
+
+function encodeStack (witnessData, witnessScript) {
+  typeforce({
+    witnessData: [types.Buffer],
+    witnessScript: types.Buffer
+  }, {
+    witnessData: witnessData,
+    witnessScript: witnessScript
+  })
+
+  return [].concat(witnessData, witnessScript)
+}
+
+function decodeStack (chunks) {
+  typeforce(check, chunks)
+  return {
+    witnessData: chunks.slice(0, -1),
+    witnessScript: chunks[chunks.length - 1]
+  }
+}
 
 module.exports = {
-  check: p2sh.check,
-  decodeStack: p2sh.decodeStack,
-  encodeStack: p2sh.encodeStack
+  check: check,
+  decodeStack: decodeStack,
+  encodeStack: encodeStack
 }