improve exception message on invalid base64 input in memory::Block

include/gradido_blockchain/GradidoBlockchainException.h

@@ -103,11 +103,11 @@ class GRADIDOBLOCKCHAIN_EXPORT GradidoUnhandledEnum : public GradidoUnknownEnumE
 class GRADIDOBLOCKCHAIN_EXPORT GradidoInvalidBase64Exception : public GradidoBlockchainException
 {
 public:
-	explicit GradidoInvalidBase64Exception(const char* what, const std::string& base64, int lastValidCharacter) noexcept;
+	explicit GradidoInvalidBase64Exception(const char* what, const std::string& base64, size_t lastValidCharacterIndex) noexcept;
 	std::string getFullString() const;
 protected:
 	std::string mBase64;
-	int         mLastValidCharacter;
+	size_t mLastValidCharacterIndex;
 
 };
 

src/GradidoBlockchainException.cpp

@@ -156,20 +156,24 @@ std::string GradidoUnknownEnumException::getFullString() const
 }
 
 // **************************** Invalid Base64 ****************************************
-GradidoInvalidBase64Exception::GradidoInvalidBase64Exception(const char* what, const std::string& base64, int lastValidCharacter) noexcept
-	: GradidoBlockchainException(what), mBase64(base64), mLastValidCharacter(lastValidCharacter)
+GradidoInvalidBase64Exception::GradidoInvalidBase64Exception(const char* what, const std::string& base64, size_t lastValidCharacterIndex) noexcept
+	: GradidoBlockchainException(what), mBase64(base64), mLastValidCharacterIndex(lastValidCharacterIndex)
 {
-
 }
 
 std::string GradidoInvalidBase64Exception::getFullString() const
 {
-	std::string resultString;
-	std::string lastValidCharacterString = std::to_string(mLastValidCharacter);
-	size_t resultSize = strlen(what()) + mBase64.size() + 10 + lastValidCharacterString.size() + 19;
+	std::string resultString;	
+	size_t resultSize = strlen(what()) + 8 + mBase64.size() + 14 + mLastValidCharacterIndex + 2;
 	resultString.reserve(resultSize);
 	resultString = what();
-	resultString += ", with: " + mBase64 + ", last valid char: " + lastValidCharacterString;
+	resultString += ", with: " + mBase64 + ", valid part: ";
+	if(mLastValidCharacterIndex < mBase64.size()) {
+		resultString += mBase64.substr(0, mLastValidCharacterIndex);
+	} else {
+		resultString += mBase64;
+	}
+
 	return resultString;
 }
 

src/memory/Block.cpp

@@ -139,7 +139,7 @@ namespace memory {
 		const char* firstInvalidByte = nullptr;
 		auto convertResult = sodium_base642bin(bin, binSize, base64String, size, nullptr, &resultBinSize, &firstInvalidByte, variant);
 		if (0 != convertResult) {
-			throw GradidoInvalidBase64Exception("invalid base64", base64String, (int)*firstInvalidByte);
+			throw GradidoInvalidBase64Exception("invalid base64", base64String, firstInvalidByte - base64String);
 		}
 		if (resultBinSize < binSize) {
 			memory::Block bin_real(resultBinSize, bin);

test/MemoryBlockTest.cpp

@@ -145,6 +145,12 @@ TEST(BlockTest, ConvertToAndFromBase64) {
 
 	// invalid base64
 	EXPECT_THROW(Block::fromBase64("AAECAwQFBgcICQ"), GradidoInvalidBase64Exception);
+	try {
+		Block::fromBase64("AAECAwQFBgc");
+		printf("valid\n");
+	} catch(GradidoInvalidBase64Exception& ex) {
+		printf("invalid base64: %s\n", ex.getFullString().data());
+	}
 }
 
 TEST(BlockTest, Blake2bHash) {
@@ -193,4 +199,4 @@ TEST(BlockTest, CopyAsVector) {
 	for (size_t i = 0; i < block.size(); ++i) {
 		EXPECT_EQ(copyVec[i], static_cast<char>(block.data()[i]));
 	}
-}
+}