refactor: sign messages eip191

Author: alexbarnsley

src/Utils/Message.php

@@ -16,6 +16,8 @@
 
 class Message
 {
+    const MESSAGE_PREFIX = "\x19Ethereum Signed Message:\n";
+
     /**
      * The message signer public key.
      *
@@ -99,7 +101,7 @@ public static function sign(string $message, string $passphrase): self
     {
         $privateKey = PrivateKey::fromPassphrase($passphrase);
 
-        $hash = Keccak::hash($message, 256);
+        $hash = Keccak::hash(static::MESSAGE_PREFIX.strlen($message).$message, 256);
 
         $signature = $privateKey->sign(Buffer::hex($hash));
 
@@ -125,10 +127,14 @@ public function verify(): bool
 
         $signature = $this->getSignature();
 
-        return $factory->fromHex($this->publicKey)->verify(
-            Buffer::hex(Keccak::hash($this->message, 256)),
-            $signature,
-        );
+        $message = static::MESSAGE_PREFIX.strlen($this->message).$this->message;
+
+        return $factory
+            ->fromHex($this->publicKey)
+            ->verify(
+                Buffer::hex(Keccak::hash($message, 256)),
+                $signature,
+            );
     }
 
     /**

tests/Unit/Utils/MessageTest.php

@@ -10,7 +10,7 @@
     $message = Message::sign($fixture['message'], $this->passphrase);
 
     expect($message->publicKey)->toBe($fixture['publicKey']);
-    expect($message->signature)->toBe($fixture['signature']);
+    expect($message->signature)->toBe(substr($fixture['signature'], 2));
     expect($message->message)->toBe($fixture['message']);
 });
 
@@ -64,7 +64,9 @@
 });
 
 test('it should verify a message', function () {
-    $message = Message::new($this->getFixture('message-sign'));
+    $fixture = $this->getFixture('message-sign');
+    $fixture['signature'] = substr($fixture['signature'], 2);
+    $message = Message::new($fixture);
 
     expect($message->verify())->toBeTrue();
 });

tests/fixtures/message-sign.json

@@ -1,5 +1,5 @@
 {
 	"message": "Hello, world!",
 	"publicKey": "0243333347c8cbf4e3cbc7a96964181d02a2b0c854faa2fef86b4b8d92afcf473d",
-	"signature": "0e2e53409be748834cac44052817ecef569b429a0492aa6bbc0d934eb71a09547e77aeef33d45669bbcba0498149f0e2b637fe8905186e08a5410c6f2b013bb400"
+	"signature": "0x2bdd0c58ff8a25f456065fb731c73308a25d0a09f351f23e3c7dd3882776d33d626b0cafc0b99dd7504b24f6ecd2e036a267c8e5e005f36dcbc03b2e33fa7fc301"
 }