add generatePublicKey from private key

fluency03 · Apr 27, 2018 · afbaabc · afbaabc
1 parent 6e5508f
commit afbaabc
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diff --git a/src/main/scala/com/fluency03/blockchain/Crypto.scala b/src/main/scala/com/fluency03/blockchain/Crypto.scala
@@ -47,6 +47,10 @@ object Crypto {
     gen.generateKeyPair()
   }
 
+  def generatePublicKey(privateKey: PrivateKey): PublicKey =
+    KeyFactory.getInstance(KEY_ALGORITHM)
+      .generatePublic(new ECPublicKeySpec(ecSpec.getG.multiply(privateKey.asInstanceOf[ECPrivateKey].getD), ecSpec))
+
   def recoverPublicKey(hex: String): PublicKey =
     KeyFactory.getInstance(KEY_ALGORITHM)
       .generatePublic(new ECPublicKeySpec(ecSpec.getCurve.decodePoint(hex.hex2Bytes), ecSpec))

diff --git a/src/test/scala/com/fluency03/blockchain/CryptoTest.scala b/src/test/scala/com/fluency03/blockchain/CryptoTest.scala
@@ -15,6 +15,7 @@ class CryptoTest extends FlatSpec with Matchers {
     val signature = sign(data, pair.getPrivate.getEncoded)
     verify(data, pair.getPublic.getEncoded, signature) shouldEqual true
 
+    generatePublicKey(pair.getPrivate) shouldEqual pair.getPublic
     recoverPublicKey(publicKeyToHex(pair.getPublic)) shouldEqual pair.getPublic
     recoverPrivateKey(privateKeyToHex(pair.getPrivate)) shouldEqual pair.getPrivate
   }