From dbba3227c114856ac581abee00b5c64986e73c16 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20=C5=9Al=C4=85ski?= <pawel.slaski@iohk.io>
Date: Mon, 30 Nov 2020 10:20:15 +0100
Subject: [PATCH] Added signature validator tool

---
 src/main/scala/io/iohk/ethereum/App.scala     |  6 ++-
 .../ethereum/crypto/SignatureValidator.scala  | 48 +++++++++++++++++++
 src/universal/bin/signatureValidator          |  5 ++
 3 files changed, 57 insertions(+), 2 deletions(-)
 create mode 100644 src/main/scala/io/iohk/ethereum/crypto/SignatureValidator.scala
 create mode 100755 src/universal/bin/signatureValidator

diff --git a/src/main/scala/io/iohk/ethereum/App.scala b/src/main/scala/io/iohk/ethereum/App.scala
index 6cd85a0288..3afe8b4419 100644
--- a/src/main/scala/io/iohk/ethereum/App.scala
+++ b/src/main/scala/io/iohk/ethereum/App.scala
@@ -1,7 +1,7 @@
 package io.iohk.ethereum
 
 import io.iohk.ethereum.cli.CliLauncher
-import io.iohk.ethereum.crypto.EcKeyGen
+import io.iohk.ethereum.crypto.{EcKeyGen, SignatureValidator}
 import io.iohk.ethereum.extvm.VmServerApp
 import io.iohk.ethereum.faucet.Faucet
 import io.iohk.ethereum.mallet.main.Mallet
@@ -19,6 +19,7 @@ object App extends Logger {
     val faucet = "faucet"
     val ecKeyGen = "eckeygen"
     val cli = "cli"
+    val sigValidator = "signature-validator"
 
     args.headOption match {
       case None => Mantis.main(args)
@@ -33,12 +34,13 @@ object App extends Logger {
       case Some(`mallet`) => Mallet.main(args.tail)
       case Some(`faucet`) => Faucet.main(args.tail)
       case Some(`ecKeyGen`) => EcKeyGen.main(args.tail)
+      case Some(`sigValidator`) => SignatureValidator.main(args.tail)
       case Some(`cli`) => CliLauncher.main(args.tail)
       case Some(unknown) =>
         log.error(
           s"Unrecognised launcher option, " +
             s"first parameter must be $launchKeytool, $downloadBootstrap, $launchMantis, " +
-            s"$mallet, $faucet, $vmServer, $ecKeyGen or $cli"
+            s"$mallet, $faucet, $vmServer, $ecKeyGen, $sigValidator or $cli"
         )
     }
 
diff --git a/src/main/scala/io/iohk/ethereum/crypto/SignatureValidator.scala b/src/main/scala/io/iohk/ethereum/crypto/SignatureValidator.scala
new file mode 100644
index 0000000000..073aa69f49
--- /dev/null
+++ b/src/main/scala/io/iohk/ethereum/crypto/SignatureValidator.scala
@@ -0,0 +1,48 @@
+package io.iohk.ethereum.crypto
+
+import akka.util.ByteString
+import io.iohk.ethereum.crypto
+import io.iohk.ethereum.jsonrpc.JsonMethodsImplicits
+import io.iohk.ethereum.nodebuilder.SecureRandomBuilder
+import io.iohk.ethereum.utils.ByteStringUtils
+
+import scala.util.{Failure, Success, Try}
+
+object SignatureValidator extends App with SecureRandomBuilder with JsonMethodsImplicits {
+
+  args match {
+    case Array(pk, sig, msgHash) =>
+      Try {
+        val signature = ECDSASignature.fromBytes(ByteString(decode(sig)))
+        val msg = ByteStringUtils.string2hash(msgHash)
+
+        signature.flatMap(_.publicKey(msg))
+      } match {
+        case Failure(exception) =>
+          println(s"Can't recover public key from signature [$sig] and msg [$msgHash]: ERROR: ${exception.getMessage}")
+          sys.exit(1)
+        case Success(recoveredPk) =>
+          val publicKey = ByteStringUtils.string2hash(pk)
+          recoveredPk match {
+            case Some(pk) =>
+              if(pk == publicKey) {
+                println(s"Recovered public key [${ByteStringUtils.hash2string(pk)}] is the same as given one")
+              } else {
+                println(s"Recovered public key [${ByteStringUtils.hash2string(pk)}] is different than given [${ByteStringUtils.hash2string(publicKey)}]")
+                sys.exit(1)
+              }
+            case None =>
+              println(s"Can't recover public key from signature [$sig] and msg [$msgHash]")
+              sys.exit(1)
+          }
+      }
+    case _ =>
+      val keyPair = crypto.generateKeyPair(secureRandom)
+      val pkStr = ByteStringUtils.hash2string(ByteString(crypto.pubKeyFromKeyPair(keyPair)))
+      val hash = kec256(Array(1.toByte))
+      val hashStr = ByteStringUtils.hash2string(ByteString(hash))
+      val signature = ECDSASignature.sign(hash, keyPair)
+      val sigStr = ByteStringUtils.hash2string(signature.toBytes)
+      println(s"Bad Input. Example usage: [signature-validator publicKey signature message_hash]. Example: [signature-validator $pkStr $sigStr $hashStr]")
+  }
+}
diff --git a/src/universal/bin/signatureValidator b/src/universal/bin/signatureValidator
new file mode 100755
index 0000000000..f09bc762e2
--- /dev/null
+++ b/src/universal/bin/signatureValidator
@@ -0,0 +1,5 @@
+#!/bin/bash
+
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+cd $DIR/..
+./bin/mantis -- signature-validator "$@"