Natspechandler: Get function hash from transaction data

alethzero/MainWin.cpp

@@ -2294,6 +2294,11 @@ std::string Main::lookupNatSpecUserNotice(dev::h256 const& _contractHash, std::s
 	return m_natspecDB.getUserNotice(_contractHash, _methodName);
 }
 
+std::string Main::lookupNatSpecUserNotice(dev::h256 const& _contractHash, dev::bytes const& _transactionData)
+{
+	return m_natspecDB.getUserNotice(_contractHash, _transactionData);
+}
+
 void Main::refreshWhispers()
 {
 	ui->whispers->clear();

alethzero/MainWin.h

@@ -84,6 +84,7 @@ public:
 
 	std::string lookupNatSpec(dev::h256 const& _contractHash) const;
 	std::string lookupNatSpecUserNotice(dev::h256 const& _contractHash, std::string const& _methodName);
+	std::string lookupNatSpecUserNotice(dev::h256 const& _contractHash, dev::bytes const& _transactionData);
 
 	QList<dev::KeyPair> owned() const { return m_myIdentities + m_myKeys; }
 

alethzero/NatspecHandler.cpp

@@ -25,7 +25,9 @@
 
 #include <libethereum/Defaults.h>
 #include <libdevcore/Common.h>
+#include <libdevcore/CommonData.h>
 #include <libdevcore/Log.h>
+#include <libdevcrypto/SHA3.h>
 
 
 using namespace dev;
@@ -62,14 +64,43 @@ std::string NatspecHandler::getUserNotice(std::string const& json, std::string c
 	Json::Value natspec, userNotice;
 	std::string retStr;
 	m_reader.parse(json, natspec);
-	retStr = natspec["methods"][_methodName]["notice"].toStyledString();
+	retStr = natspec["methods"][_methodName]["notice"].asString();
 
 	return (retStr == "null\n") ? "" : retStr;
 }
 
+std::string NatspecHandler::getUserNotice(std::string const& json, const dev::bytes& _transactionData)
+{
+	Json::Value natspec, userNotice;
+	std::string retStr;
+	m_reader.parse(json, natspec);
+	bytes transactionFunctionPart(_transactionData.begin(), _transactionData.begin() + 4);
+	FixedHash<4> transactionFunctionHash(transactionFunctionPart);
+
+	// for (auto const& it: natspec["methods"])
+	Json::Value methods = natspec["methods"];
+	for (Json::ValueIterator it= methods.begin(); it != methods.end(); ++it )
+	{
+		std::string functionSig = it.key().asString();
+		FixedHash<4> functionHash(dev::sha3(functionSig));
+
+		if (functionHash == transactionFunctionHash) {
+			return (*it)["notice"].asString();
+		}
+	}
+
+	// not found
+	return "";
+}
+
 std::string NatspecHandler::getUserNotice(dev::h256 const& _contractHash, std::string const& _methodName)
 {
 	return getUserNotice(retrieve(_contractHash), _methodName);
 }
 
+std::string NatspecHandler::getUserNotice(dev::h256 const& _contractHash, dev::bytes const& _transactionData)
+{
+	return getUserNotice(retrieve(_contractHash), _transactionData);
+}
+
 

alethzero/NatspecHandler.h

@@ -43,10 +43,14 @@ class NatspecHandler
 
 	/// Given a json natspec string, retrieve the user notice string
 	std::string getUserNotice(std::string const& json, std::string const& _methodName);
+	std::string getUserNotice(std::string const& json, const dev::bytes& _transactionData);
 	/// Given a contract code hash, retrieve the natspec documentation's user notice for that contract
+	std::string getUserNotice(dev::h256 const& _contractHash, std::string const& _methodName);
+	/// Given a contract code hash and the transaction's data retrieve the natspec documention's
+	/// user notice for that transaction.
 	/// @returns The user notice or an empty string if no natspec for the contract exists
 	///          or if the existing natspec does not document the @c _methodName
-	std::string getUserNotice(dev::h256 const& _contractHash, std::string const& _methodName);
+	std::string getUserNotice(dev::h256 const& _contractHash, dev::bytes const& _transactionDacta);
 	
   private:
 	ldb::ReadOptions m_readOptions;

alethzero/OurWebThreeStubServer.cpp

@@ -22,6 +22,7 @@
 #include "OurWebThreeStubServer.h"
 
 #include <QMessageBox>
+#include <QAbstractButton>
 #include <libwebthree/WebThree.h>
 #include "MainWin.h"
 
@@ -62,7 +63,8 @@ bool OurWebThreeStubServer::authenticate(dev::TransactionSkeleton const& _t) con
 
 
 	//LTODO: Actually find and use the method name  here
-	std::string userNotice = m_main->lookupNatSpecUserNotice(contractCodeHash, "multiply");
+	// std::string userNotice = m_main->lookupNatSpecUserNotice(contractCodeHash, "multiply");
+	std::string userNotice = m_main->lookupNatSpecUserNotice(contractCodeHash, _t.data);
 	if (userNotice.empty())
 	{
 		QMessageBox userInput;
@@ -77,8 +79,10 @@ bool OurWebThreeStubServer::authenticate(dev::TransactionSkeleton const& _t) con
 	// otherwise it's a transaction to a contract for which we have the natspec
 	QMessageBox userInput;
 	userInput.setText("Pending Transaction");
-	userInput.setInformativeText(QString::fromStdString(userNotice));
+	userInput.setInformativeText(QString::fromStdString(userNotice + "\n Do you wish to allow this?"));
 	userInput.setStandardButtons(QMessageBox::Ok | QMessageBox::Cancel);
+	userInput.button(QMessageBox::Ok)->setText("Allow");
+	userInput.button(QMessageBox::Cancel)->setText("Reject");
 	userInput.setDefaultButton(QMessageBox::Cancel);
 	return userInput.exec() == QMessageBox::Ok;
 

libjsqrc/ethereumjs/example/natspec_contract.html

@@ -12,7 +12,7 @@
     // solidity source code
     var source = "" + 
     "contract test {\n" +
-    "   /// @notice This is an awesome function for multiplication. \n" +
+    "   /// @notice Will multiplty `a` by 7. \n" +
     "   function multiply(uint a) returns(uint d) {\n" +
     "       return a * 7;\n" +
     "   }\n" +