From 67957afb6ba01bcd85f1abd1a50ad2c1aa813c7c Mon Sep 17 00:00:00 2001
From: Aleksi Lindeman <0xdec05eba@gmail.com>
Date: Wed, 14 Feb 2018 22:18:48 +0100
Subject: Sign messages/verify message signatures

---
 src/Signature.cpp | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

(limited to 'src/Signature.cpp')

diff --git a/src/Signature.cpp b/src/Signature.cpp
index 946d754..8d3654d 100644
--- a/src/Signature.cpp
+++ b/src/Signature.cpp
@@ -35,6 +35,19 @@ namespace odhtdb
             return *this;
         }
         
+        string PublicKey::unsign(const DataView &signedMessage) const
+        {
+            if(signedMessage.size < SIGNED_HASH_SIZE)
+                throw UnsignInvalidSizeException("Signed message is too small (corrupt or malicious signed message)");
+            
+            string result;
+            result.resize(signedMessage.size - SIGNED_HASH_SIZE);
+            if(crypto_sign_ed25519_open((unsigned char*)&result[0], nullptr, (const unsigned char*)signedMessage.data, signedMessage.size, (unsigned char*)data) != 0)
+                throw UnsignWrongKeyException("Message was not signed with matching private key");
+            
+            return result;
+        }
+        
         string PublicKey::toString() const
         {
             string result;
@@ -67,13 +80,13 @@ namespace odhtdb
             return *this;
         }
         
-        string PrivateKey::sign(const string &dataToSign) const
+        string PrivateKey::sign(const DataView &dataToSign) const
         {
             string result;
-            result.resize(crypto_sign_ed25519_BYTES + dataToSign.size());
+            result.resize(crypto_sign_ed25519_BYTES + dataToSign.size);
             unsigned long long resultSize;
             
-            if(crypto_sign_ed25519((unsigned char*)&result[0], &resultSize, (unsigned char*)dataToSign.data(), dataToSign.size(), (unsigned char*)data) != 0)
+            if(crypto_sign_ed25519((unsigned char*)&result[0], &resultSize, (unsigned char*)dataToSign.data, dataToSign.size, (unsigned char*)data) != 0)
                 throw DataSignException("Failed to sign data. Is private key invalid?");
             
             if(resultSize != result.size())
-- 
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