segwit support

Author: andkom

composer.json

@@ -16,7 +16,8 @@
   "require": {
     "php": "^7.1",
     "andkom/bcdatastream": "^1.0",
-    "stephenhill/base58": "^1.1"
+    "stephenhill/base58": "^1.1",
+    "bitwasp/bech32": "^0.0.1"
   },
   "require-dev": {
     "phpunit/phpunit": ">=5.0"

src/Input.php

@@ -33,6 +33,11 @@ class Input
      */
     public $sequenceNo;
 
+    /**
+     * @var array
+     */
+    public $witnesses = [];
+
     /**
      * @param Reader $stream
      * @return Input

src/Network/Bitcoin.php

@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace AndKom\PhpBitcoinBlockchain\Network;
+
+/**
+ * Class Bitcoin
+ * @package AndKom\PhpBitcoinBlockchain\Network
+ */
+class Bitcoin
+{
+    const P2PKH_PREFIX = 0x00;
+    const P2SH_PREFIX = 0x05;
+    const BECH32_HRP = 'bc';
+}

src/ScriptPubKey.php

@@ -4,6 +4,9 @@
 
 namespace AndKom\PhpBitcoinBlockchain;
 
+use AndKom\PhpBitcoinBlockchain\Network\Bitcoin;
+use function BitWasp\Bech32\encodeSegwit;
+
 /**
  * Class ScriptPubKey
  * @package AndKom\PhpBitcoinBlockchain
@@ -75,26 +78,61 @@ public function isMultisig(): bool
     }
 
     /**
+     * @return bool
+     */
+    public function isP2WPKH(): bool
+    {
+        $operations = $this->parse();
+
+        return (count($operations) == 2) &&
+            ord($operations[0]->data) == 0 &&
+            $operations[1]->size == 20;
+    }
+
+    /**
+     * @return bool
+     */
+    public function isP2WSH(): bool
+    {
+        $operations = $this->parse();
+
+        return (count($operations) == 2) &&
+            ord($operations[0]->data) == 0 &&
+            $operations[1]->size == 32;
+    }
+
+    /**
+     * @param Bitcoin|null $network
      * @return string
      * @throws Exception
+     * @throws \BitWasp\Bech32\Exception\Bech32Exception
      */
-    public function getOutputAddress(): string
+    public function getOutputAddress(Bitcoin $network = null): string
     {
+        if (!$network) {
+            $network = new Bitcoin();
+        }
+
         $operations = $this->parse();
 
         if ($this->isP2PK()) {
-            $pubKey = $operations[0]->data;
-            return Utils::pubKeyToAddress($pubKey, 0x00);
+            return Utils::pubKeyToAddress($operations[0]->data, $network::P2PKH_PREFIX);
         }
 
         if ($this->isP2PKH()) {
-            $pubKeyHash = $operations[2]->data;
-            return Utils::hash160ToAddress($pubKeyHash, 0x00);
+            return Utils::hash160ToAddress($operations[2]->data, $network::P2PKH_PREFIX);
         }
 
         if ($this->isP2SH()) {
-            $hash = $operations[1]->data;
-            return Utils::hash160ToAddress($hash, 0x05);
+            return Utils::hash160ToAddress($operations[1]->data, $network::P2SH_PREFIX);
+        }
+
+        if ($this->isP2WPKH()) {
+            return encodeSegwit($network::BECH32_HRP, $operations[0]->data, $operations[1]->data);
+        }
+
+        if ($this->isP2WSH()) {
+            return encodeSegwit($network::BECH32_HRP, $operations[0]->data, $operations[1]->data);
         }
 
         throw new Exception('Unable to decode output address.');

src/Transaction.php

@@ -21,7 +21,7 @@ class Transaction
     /**
      * @var int
      */
-    public $flag;
+    public $isSegwit = false;
 
     /**
      * @var int
@@ -43,11 +43,6 @@ class Transaction
      */
     public $outputs = [];
 
-    /**
-     * @var array
-     */
-    public $witnesses = [];
-
     /**
      * @var int
      */
@@ -61,6 +56,13 @@ static public function parse(Reader $stream): self
     {
         $tx = new self;
         $tx->version = $stream->readUInt32();
+
+        $tx->isSegwit = $stream->read(2) == "\x00\x01";
+
+        if (!$tx->isSegwit) {
+            $stream->setPosition($stream->getPosition() - 2);
+        }
+
         $tx->inCount = $stream->readVarInt();
 
         for ($i = 0; $i < $tx->inCount; $i++) {
@@ -73,18 +75,33 @@ static public function parse(Reader $stream): self
             $tx->outputs[] = Output::parse($stream);
         }
 
+        if ($tx->isSegwit) {
+            foreach ($tx->inputs as $input) {
+                $count = $stream->readVarInt();
+                for ($i = 0; $i < $count; $i++) {
+                    $input->witnesses[] = $stream->readString();
+                }
+            }
+        }
+
         $tx->lockTime = $stream->readInt32();
 
         return $tx;
     }
 
     /**
      * @param Writer $stream
+     * @param bool $segWit
      * @return Transaction
      */
-    public function serialize(Writer $stream): self
+    public function serialize(Writer $stream, bool $segWit = true): self
     {
         $stream->writeUInt32($this->version);
+
+        if ($this->isSegwit && $segWit) {
+            $stream->write("\x00\x01");
+        }
+
         $stream->writeVarInt($this->inCount);
 
         foreach ($this->inputs as $in) {
@@ -97,18 +114,29 @@ public function serialize(Writer $stream): self
             $out->serialize($stream);
         }
 
+        if ($this->isSegwit && $segWit) {
+            foreach ($this->inputs as $input) {
+                $stream->writeVarInt(count($input->witnesses));
+
+                foreach ($input->witnesses as $witness) {
+                    $stream->writeString($witness);
+                }
+            }
+        }
+
         $stream->writeInt32($this->lockTime);
 
         return $this;
     }
 
     /**
+     * @param bool $segWit
      * @return string
      */
-    public function getHash(): string
+    public function getHash(bool $segWit = false): string
     {
         $stream = new Writer();
-        $this->serialize($stream);
+        $this->serialize($stream, $segWit);
         $hash = Utils::hash($stream->getBuffer(), true);
         $hash = strrev($hash);
         $hash = bin2hex($hash);

tests/ScriptPubKeyTest.php

@@ -92,4 +92,30 @@ public function testParseMultisig()
 
         $this->assertTrue($script->isMultisig());
     }
+
+    // [segwit ver] [pubkey hash]
+    public function testParseP2WPKH()
+    {
+        $hex = '00'; // segwit version
+        $hex .= '14'; // OP_PUSHDATA
+        $hex .= '536523b38a207338740797cd03c3312e81408d53'; // pubkey hash
+
+        $script = new ScriptPubKey(hex2bin($hex));
+
+        $this->assertTrue($script->isP2WPKH());
+        $this->assertEquals($script->getOutputAddress(), 'bc1q2djj8vu2ypensaq8jlxs8se396q5pr2n3sa2wn');
+    }
+
+    // [segwit ver] [pubkey hash]
+    public function testParseP2WSH()
+    {
+        $hex = '00'; // segwit version
+        $hex .= '20'; // OP_PUSHDATA
+        $hex .= '701a8d401c84fb13e6baf169d59684e17abd9fa216c8cc5b9fc63d622ff8c58d'; // hash
+
+        $script = new ScriptPubKey(hex2bin($hex));
+
+        $this->assertTrue($script->isP2WSH());
+        $this->assertEquals($script->getOutputAddress(), 'bc1qwqdg6squsna38e46795at95yu9atm8azzmyvckulcc7kytlcckxswvvzej');
+    }
 }

tests/TransactionTest.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace AndKom\PhpBitcoinBlockchain;
+
+use AndKom\BCDataStream\Reader;
+use AndKom\BCDataStream\Writer;
+use PHPUnit\Framework\TestCase;
+
+class TransactionTest extends TestCase
+{
+    public function testSegwit()
+    {
+        $hex = '01000000000101a4be5f1271ba9742925a13ad6dbde1edba930691235ce0c1ea5f19d17c50795c0100000000ffffffff024c69c60700000000160014536523b38a207338740797cd03c3312e81408d5319d916000000000017a9140bd991e785337804568db45edb4ef00aa89377a9870247304402204dfb80ded7cdd60ae9b702d428c8f27c4c4dafda65452c7efd48d0d5b1f1766d022026423d627f851b94e04b53dc2df93666d924067f87ca4c785ec0c3ef9491fd72012103eee8e1747dcdb2dceba826a1dc9ea701f438ff9aa1ee466df6372a05cb246d3000000000';
+
+        $reader = new Reader(hex2bin($hex));
+        $transaction = Transaction::parse($reader);
+
+        $this->assertEquals($transaction->isSegwit, true);
+        $this->assertEquals($transaction->getHash(), '2db64f394b10eee0a1d642ea8e390af7595c9bfdb6d25b0ddc21e9112212e95c');
+
+        $writer = new Writer();
+        $transaction->serialize($writer);
+
+        $this->assertEquals($writer->getBuffer(), hex2bin($hex));
+    }
+}