From 7345e79eecce78ff172612aa0543923af23a435c Mon Sep 17 00:00:00 2001
From: Thorsten Sommer <service@sommer-engineering.com>
Date: Fri, 3 Jan 2020 21:30:01 +0100
Subject: [PATCH] Fixed expected private key length

---
 Ed25519/Signer.cs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Ed25519/Signer.cs b/Ed25519/Signer.cs
index aa85ea0..82adeff 100644
--- a/Ed25519/Signer.cs
+++ b/Ed25519/Signer.cs
@@ -10,8 +10,8 @@ namespace Ed25519
     {
         public static ReadOnlySpan<byte> Sign(ReadOnlySpan<byte> message, ReadOnlySpan<byte> privateKey, ReadOnlySpan<byte> publicKey)
         {
-            if(privateKey.Length == 0)
-                throw new ArgumentException("Private key length is wrong. Key must not be empty.");
+            if(privateKey.Length != Constants.BIT_LENGTH / 8)
+                throw new ArgumentException($"Private key length is wrong. Got {publicKey.Length} instead of {Constants.BIT_LENGTH / 8}.");
 
             if (publicKey.Length != Constants.BIT_LENGTH / 8)
                 throw new ArgumentException($"Public key length is wrong. Got {publicKey.Length} instead of {Constants.BIT_LENGTH / 8}.");