From 80762543e701fc6b35d304444ec4e027051f77db Mon Sep 17 00:00:00 2001
From: Daniel Cousens <github@dcousens.com>
Date: Wed, 14 Dec 2016 15:52:38 +1100
Subject: [PATCH] templates: add encode/decode* stack functions

---
 src/templates/index.js                   |  4 +--
 src/templates/multisig/input.js          | 23 +++++++++++-----
 src/templates/pubkey/input.js            | 22 ++++++++++-----
 src/templates/pubkeyhash/input.js        | 26 ++++++++++++------
 src/templates/scripthash/input.js        | 35 ++++++++++++++++--------
 src/templates/witnesspubkeyhash/index.js |  1 +
 src/templates/witnesspubkeyhash/input.js |  9 ++++++
 src/templates/witnessscripthash/index.js |  1 +
 src/templates/witnessscripthash/input.js |  9 ++++++
 9 files changed, 94 insertions(+), 36 deletions(-)
 create mode 100644 src/templates/witnesspubkeyhash/input.js
 create mode 100644 src/templates/witnessscripthash/input.js

diff --git a/src/templates/index.js b/src/templates/index.js
index fa7c4ea..72143f1 100644
--- a/src/templates/index.js
+++ b/src/templates/index.js
@@ -52,8 +52,8 @@ function classifyWitness (script, allowIncomplete) {
   // XXX: optimization, below functions .decompile before use
   var chunks = decompile(script)
 
-  if (pubKeyHash.input.check(chunks)) return types.P2WPKH
-  if (scriptHash.input.check(chunks)) return types.P2WSH
+  if (witnessPubKeyHash.input.check(chunks)) return types.P2WPKH
+  if (witnessScriptHash.input.check(chunks)) return types.P2WSH
 
   return types.NONSTANDARD
 }
diff --git a/src/templates/multisig/input.js b/src/templates/multisig/input.js
index aed80af..d3e230c 100644
--- a/src/templates/multisig/input.js
+++ b/src/templates/multisig/input.js
@@ -21,7 +21,7 @@ function check (script, allowIncomplete) {
 }
 check.toJSON = function () { return 'multisig input' }
 
-function encode (signatures, scriptPubKey) {
+function encodeStack (signatures, scriptPubKey) {
   typeforce([partialSignature], signatures)
 
   if (scriptPubKey) {
@@ -36,18 +36,27 @@ function encode (signatures, scriptPubKey) {
     }
   }
 
-  return bscript.compile([].concat(OPS.OP_0, signatures))
+  return [].concat(OPS.OP_0, signatures)
 }
 
-function decode (buffer, allowIncomplete) {
-  var chunks = bscript.decompile(buffer)
-  typeforce(check, chunks, allowIncomplete)
+function encode (signatures, scriptPubKey) {
+  return bscript.compile(encodeStack(signatures, scriptPubKey))
+}
 
-  return chunks.slice(1)
+function decodeStack (stack, allowIncomplete) {
+  typeforce(check, stack, allowIncomplete)
+  return stack.slice(1)
+}
+
+function decode (buffer, allowIncomplete) {
+  var stack = bscript.decompile(buffer)
+  return decodeStack(stack, allowIncomplete)
 }
 
 module.exports = {
   check: check,
   decode: decode,
-  encode: encode
+  decodeStack: decodeStack,
+  encode: encode,
+  encodeStack: encodeStack
 }
diff --git a/src/templates/pubkey/input.js b/src/templates/pubkey/input.js
index 7357adc..0e8ed8d 100644
--- a/src/templates/pubkey/input.js
+++ b/src/templates/pubkey/input.js
@@ -12,21 +12,29 @@ function check (script) {
 }
 check.toJSON = function () { return 'pubKey input' }
 
-function encode (signature) {
+function encodeStack (signature) {
   typeforce(types.Buffer, signature)
+  return [signature]
+}
+
+function encode (signature) {
+  return bscript.compile(encodeStack(signature))
+}
 
-  return bscript.compile([signature])
+function decodeStack (stack) {
+  typeforce(check, stack)
+  return stack[0]
 }
 
 function decode (buffer) {
-  var chunks = bscript.decompile(buffer)
-  typeforce(check, chunks)
-
-  return chunks[0]
+  var stack = bscript.decompile(buffer)
+  return decodeStack(stack)
 }
 
 module.exports = {
   check: check,
   decode: decode,
-  encode: encode
+  decodeStack: decodeStack,
+  encode: encode,
+  encodeStack: encodeStack
 }
diff --git a/src/templates/pubkeyhash/input.js b/src/templates/pubkeyhash/input.js
index d085da7..82b89f9 100644
--- a/src/templates/pubkeyhash/input.js
+++ b/src/templates/pubkeyhash/input.js
@@ -13,28 +13,38 @@ function check (script) {
 }
 check.toJSON = function () { return 'pubKeyHash input' }
 
-function encode (signature, pubKey) {
+function encodeStack (signature, pubKey) {
   typeforce({
     signature: types.Buffer, pubKey: types.Buffer
   }, {
     signature: signature, pubKey: pubKey
   })
 
-  return bscript.compile([signature, pubKey])
+  return [signature, pubKey]
 }
 
-function decode (buffer) {
-  var chunks = bscript.decompile(buffer)
-  typeforce(check, chunks)
+function encode (signature, pubKey) {
+  return bscript.compile(encodeStack(signature, pubKey))
+}
+
+function decodeStack (stack) {
+  typeforce(check, stack)
 
   return {
-    signature: chunks[0],
-    pubKey: chunks[1]
+    signature: stack[0],
+    pubKey: stack[1]
   }
 }
 
+function decode (buffer) {
+  var stack = bscript.decompile(buffer)
+  return decodeStack(stack)
+}
+
 module.exports = {
   check: check,
   decode: decode,
-  encode: encode
+  decodeStack: decodeStack,
+  encode: encode,
+  encodeStack: encodeStack
 }
diff --git a/src/templates/scripthash/input.js b/src/templates/scripthash/input.js
index adf1cec..ce2bef7 100644
--- a/src/templates/scripthash/input.js
+++ b/src/templates/scripthash/input.js
@@ -25,28 +25,39 @@ function check (script, allowIncomplete) {
 }
 check.toJSON = function () { return 'scriptHash input' }
 
-function encode (redeemScriptSig, redeemScript) {
-  var scriptSigChunks = bscript.decompile(redeemScriptSig)
+function encodeStack (redeemScriptStack, redeemScript) {
   var serializedScriptPubKey = bscript.compile(redeemScript)
 
-  return bscript.compile([].concat(
-    scriptSigChunks,
-    serializedScriptPubKey
-  ))
+  return [].concat(redeemScriptStack, serializedScriptPubKey)
 }
 
-function decode (buffer) {
-  var chunks = bscript.decompile(buffer)
-  typeforce(check, chunks)
+function encode (redeemScriptSig, redeemScript) {
+  var redeemScriptStack = bscript.decompile(redeemScriptSig)
+
+  return bscript.compile(encodeStack(redeemScriptStack, redeemScript))
+}
+
+function decodeStack (stack) {
+  typeforce(check, stack)
 
   return {
-    redeemScriptSig: bscript.compile(chunks.slice(0, -1)),
-    redeemScript: chunks[chunks.length - 1]
+    redeemScriptStack: stack.slice(0, -1),
+    redeemScript: stack[stack.length - 1]
   }
 }
 
+function decode (buffer) {
+  var stack = bscript.decompile(buffer)
+  var result = decodeStack(stack)
+  result.redeemScriptSig = bscript.compile(result.redeemScriptStack)
+  delete result.redeemScriptStack
+  return result
+}
+
 module.exports = {
   check: check,
   decode: decode,
-  encode: encode
+  decodeStack: decodeStack,
+  encode: encode,
+  encodeStack: encodeStack
 }
diff --git a/src/templates/witnesspubkeyhash/index.js b/src/templates/witnesspubkeyhash/index.js
index d459038..46863d6 100644
--- a/src/templates/witnesspubkeyhash/index.js
+++ b/src/templates/witnesspubkeyhash/index.js
@@ -1,3 +1,4 @@
 module.exports = {
+  input: require('./input'),
   output: require('./output')
 }
diff --git a/src/templates/witnesspubkeyhash/input.js b/src/templates/witnesspubkeyhash/input.js
new file mode 100644
index 0000000..d9d678b
--- /dev/null
+++ b/src/templates/witnesspubkeyhash/input.js
@@ -0,0 +1,9 @@
+// {signature} {pubKey}
+
+var pkh = require('../pubkeyhash/input')
+
+module.exports = {
+  check: pkh.check,
+  decodeStack: pkh.decodeStack,
+  encodeStack: pkh.encodeStack
+}
diff --git a/src/templates/witnessscripthash/index.js b/src/templates/witnessscripthash/index.js
index d459038..46863d6 100644
--- a/src/templates/witnessscripthash/index.js
+++ b/src/templates/witnessscripthash/index.js
@@ -1,3 +1,4 @@
 module.exports = {
+  input: require('./input'),
   output: require('./output')
 }
diff --git a/src/templates/witnessscripthash/input.js b/src/templates/witnessscripthash/input.js
new file mode 100644
index 0000000..02b6545
--- /dev/null
+++ b/src/templates/witnessscripthash/input.js
@@ -0,0 +1,9 @@
+// {signature} {pubKey}
+
+var p2sh = require('../scripthash/input')
+
+module.exports = {
+  check: p2sh.check,
+  decodeStack: p2sh.decodeStack,
+  encodeStack: p2sh.encodeStack
+}