Guard for exceptions in FileStore::MaxRetrievable (GH #968)

1 files changed, 35 insertions, 1 deletions

diff --git a/files.cpp b/files.cpp
index 22af7097..79ea6418 100644
--- a/files.cpp
+++ b/files.cpp
@@ -6,8 +6,39 @@
 

 #include "files.h"

 

+#include <iostream>

+#include <fstream>

 #include <limits>

 

+ANONYMOUS_NAMESPACE_BEGIN

+

+/// \brief Disable badbit, failbit and eof exceptions

+/// \sa https://github.com/weidai11/cryptopp/pull/968 and

+///  https://www.cplusplus.com/reference/ios/ios/exceptions

+class IosExceptionMask

+{

+public:

+	IosExceptionMask(std::istream& stream) : m_stream(stream) {

+		m_mask = m_stream.exceptions();

+		m_stream.exceptions(static_cast<std::ios::iostate>(0));

+	}

+

+	IosExceptionMask(std::istream& stream, std::ios::iostate newMask) : m_stream(stream) {

+		m_mask = m_stream.exceptions();

+		m_stream.exceptions(newMask);

+	}

+

+	~IosExceptionMask() {

+		m_stream.exceptions(m_mask);

+	}

+

+private:

+	std::istream& m_stream;

+	std::ios::iostate m_mask;

+};

+

+ANONYMOUS_NAMESPACE_END

+

 NAMESPACE_BEGIN(CryptoPP)

 

 #if defined(CRYPTOPP_DEBUG) && !defined(CRYPTOPP_DOXYGEN_PROCESSING)

@@ -65,6 +96,9 @@ lword FileStore::MaxRetrievable() const
 	if (!m_stream)

 		return 0;

 

+	// Disable badbit, failbit and eof exceptions

+	IosExceptionMask guard(*m_stream);

+

 	// Clear error bits due to seekg(). Also see

 	// https://github.com/weidai11/cryptopp/pull/968

 	std::streampos current = m_stream->tellg();

@@ -74,7 +108,7 @@ lword FileStore::MaxRetrievable() const
 	m_stream->clear();

 

 	// Return max for a non-seekable stream

-	// https://www.cplusplus.com/reference/istream/istream/tellg/

+	// https://www.cplusplus.com/reference/istream/istream/tellg

 	if (end == static_cast<std::streampos>(-1))

 		return LWORD_MAX;