From 5e24f8fe130223d3a270b7353a93499d334839dc Mon Sep 17 00:00:00 2001
From: CryptoManiac <balthazar@yandex.ru>
Date: Mon, 17 Aug 2015 22:54:47 +0300
Subject: [PATCH] Add CKeyPair.Sign() implementation

---
 Novacoin/CKeyPair.cs    |   17 +++++++++++++++++
 NovacoinTest/Program.cs |    7 +++++++
 2 files changed, 24 insertions(+), 0 deletions(-)

diff --git a/Novacoin/CKeyPair.cs b/Novacoin/CKeyPair.cs
index 158ad70..9c5903c 100644
--- a/Novacoin/CKeyPair.cs
+++ b/Novacoin/CKeyPair.cs
@@ -51,6 +51,23 @@ namespace Novacoin
         }
 
         /// <summary>
+        /// Create signature for supplied data
+        /// </summary>
+        /// <param name="data">Data bytes sequence</param>
+        /// <returns>Signature bytes sequence</returns>
+        public IEnumerable<byte> Sign(IEnumerable<byte> data)
+        {
+            byte[] dataBytes = data.ToArray();
+
+            ISigner signer = SignerUtilities.GetSigner("SHA-256withECDSA");
+            ECPrivateKeyParameters keyParameters = new ECPrivateKeyParameters(D, domain);
+            signer.Init(true, keyParameters);
+            signer.BlockUpdate(dataBytes, 0, dataBytes.Length);
+
+            return signer.GenerateSignature();
+        }
+
+        /// <summary>
         /// Secret part of key pair
         /// </summary>
         public IEnumerable<byte> Secret
diff --git a/NovacoinTest/Program.cs b/NovacoinTest/Program.cs
index 01f9b9d..d7242ad 100644
--- a/NovacoinTest/Program.cs
+++ b/NovacoinTest/Program.cs
@@ -49,6 +49,13 @@ namespace NovacoinTest
             Console.WriteLine(keyPair1.ToString());
             Console.WriteLine("OK: {0}\n", keyPair1.ToString() == keyPair2.ToString());
 
+            /// ECDSA keypair signing test
+
+            string data = "Превед!";
+            byte[] signature = keyPair1.Sign(Encoding.UTF8.GetBytes(data)).ToArray();
+
+            Console.WriteLine("Signature: {0}", Interop.ToHex(signature));
+
             Console.ReadLine();
         }
     }
-- 
1.7.1