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

---
 include/Signature.hpp | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

(limited to 'include/Signature.hpp')

diff --git a/include/Signature.hpp b/include/Signature.hpp
index ea776ea..aace383 100644
--- a/include/Signature.hpp
+++ b/include/Signature.hpp
@@ -1,11 +1,13 @@
 #pragma once
 
+#include "DataView.hpp"
 #include <stdexcept>
 
 namespace odhtdb
 {
     const int PUBLIC_KEY_NUM_BYTES = 32;
     const int PRIVATE_KEY_NUM_BYTES = 64;
+    const int SIGNED_HASH_SIZE = 64;
     
     class InvalidSignatureKeySize : public std::runtime_error
     {
@@ -25,6 +27,25 @@ namespace odhtdb
         DataSignException(const std::string &errMsg) : std::runtime_error(errMsg) {}
     };
     
+    class UnsignException : public std::runtime_error
+    {
+    public:
+        UnsignException(const std::string &errMsg) : std::runtime_error(errMsg) {}
+        virtual ~UnsignException(){}
+    };
+    
+    class UnsignInvalidSizeException : public UnsignException
+    {
+    public:
+        UnsignInvalidSizeException(const std::string &errMsg) : UnsignException(errMsg) {}
+    };
+    
+    class UnsignWrongKeyException : public UnsignException
+    {
+    public:
+        UnsignWrongKeyException(const std::string &errMsg) : UnsignException(errMsg) {}
+    };
+    
     namespace Signature
     {
         class PublicKey
@@ -41,6 +62,11 @@ namespace odhtdb
             const char* getData() const { return data; }
             size_t getSize() const { return PUBLIC_KEY_NUM_BYTES; }
             
+            // Throws UnsignWrongKeyException if signed message was not signed using the matching private key of this public key.
+            // Throws UnsignInvalidSizeException if signed message is too small (< SIGNED_HASH_SIZE).
+            // Both exceptions are derived from UnsignException
+            std::string unsign(const DataView &signedMessage) const;
+            
             std::string toString() const;
         private:
             PublicKey(){}
@@ -61,7 +87,7 @@ namespace odhtdb
             size_t getSize() const { return PRIVATE_KEY_NUM_BYTES; }
             
             // Throws DataSignException if signing data failed for whatever reason. This wont happen unless there is an issue with the private key
-            std::string sign(const std::string &dataToSign) const;
+            std::string sign(const DataView &dataToSign) const;
             std::string toString() const;
         private:
             PrivateKey(){}
-- 
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