Support for Secure De-allocation of memory

.gitignore

@@ -45,3 +45,8 @@ jsoncpp_lib_static.dir/
 /src/lib_json/Makefile
 /src/test_lib_json/Makefile
 /src/test_lib_json/jsoncpp_test
+
+# eclipse project files
+.project
+.cproject
+/.settings/

include/json/allocator.h

@@ -0,0 +1,94 @@
+// Copyright 2007-2010 Baptiste Lepilleur
+// Distributed under MIT license, or public domain if desired and
+// recognized in your jurisdiction.
+// See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
+
+#ifndef CPPTL_JSON_ALLOCATOR_H_INCLUDED
+#define CPPTL_JSON_ALLOCATOR_H_INCLUDED
+
+#include <cstring>
+#include <memory>
+
+namespace Json {
+template<typename T>
+class SecureAllocator {
+	public:
+		// Type definitions
+		using value_type      = T;
+		using pointer         = T*;
+		using const_pointer   = const T*;
+		using reference       = T&;
+		using const_reference = const T&;
+		using size_type       = std::size_t;
+		using difference_type = std::ptrdiff_t;
+
+		/**
+		 * Allocate memory for N items using the standard allocator.
+		 */
+		pointer allocate(size_type n) {
+			// allocate using "global operator new"
+			return static_cast<pointer>(::operator new(n * sizeof(T)));
+		}
+
+		/**
+		 * Release memory which was allocated for N items at pointer P.
+		 *
+		 * The memory block is filled with zeroes before being released.
+		 * The pointer argument is tagged as "volatile" to prevent the
+		 * compiler optimizing out this critical step.
+		 */
+		void deallocate(volatile pointer p, size_type n) {
+			std::memset(p, 0, n * sizeof(T));
+			// free using "global operator delete"
+			::operator delete(p);
+		}
+
+		/**
+		 * Construct an item in-place at pointer P.
+		 */
+		template<typename... Args>
+		void construct(pointer p, Args&&... args) {
+			// construct using "placement new" and "perfect forwarding"
+			::new (static_cast<void*>(p)) T(std::forward<Args>(args)...);
+		}
+
+		size_type max_size() const {
+			return size_t(-1) / sizeof(T);
+		}
+
+		pointer address( reference x ) const {
+			return std::addressof(x);
+		}
+
+		const_pointer address( const_reference x ) const {
+			return std::addressof(x);
+		}
+
+		/**
+		 * Destroy an item in-place at pointer P.
+		 */
+		void destroy(pointer p) {
+			// destroy using "explicit destructor"
+			p->~T();
+		}
+
+		// Boilerplate
+		SecureAllocator() {}
+		template<typename U> SecureAllocator(const SecureAllocator<U>&) {}
+		template<typename U> struct rebind { using other = SecureAllocator<U>; };
+};
+
+
+template<typename T, typename U>
+bool operator==(const SecureAllocator<T>&, const SecureAllocator<U>&) {
+	return true;
+}
+
+template<typename T, typename U>
+bool operator!=(const SecureAllocator<T>&, const SecureAllocator<U>&) {
+	return false;
+}
+
+} //namespace Json
+
+#endif // CPPTL_JSON_ALLOCATOR_H_INCLUDED

include/json/config.h

@@ -6,6 +6,7 @@
 #ifndef JSON_CONFIG_H_INCLUDED
 #define JSON_CONFIG_H_INCLUDED
 #include <stddef.h>
+#include "allocator.h" //typedef Allocator
 #include <string> //typdef String
 
 /// If defined, indicates that json library is embedded in CppTL library.
@@ -119,6 +120,16 @@
 #  define JSON_USE_INT64_DOUBLE_CONVERSION 1
 #endif
 
+// If non-zero, the library zeroes any memory that it has allocated before
+// it frees its
+#ifndef JSON_USE_SECURE_MEMORY
+#define JSON_USE_SECURE_MEMORY 0
+#endif
+
+#if JSON_USE_SECURE_MEMORY
+#include "allocator.h" //typedef Allocator
+#endif
+
 namespace Json {
 typedef int Int;
 typedef unsigned int UInt;
@@ -139,11 +150,19 @@ typedef Int64 LargestInt;
 typedef UInt64 LargestUInt;
 #define JSON_HAS_INT64
 #endif // if defined(JSON_NO_INT64)
+#if JSON_USE_SECURE_MEMORY
+#define JSONCPP_STRING        std::basic_string<char, std::char_traits<char>, Json::SecureAllocator<char> >
+#define JSONCPP_OSTRINGSTREAM std::basic_ostringstream<char, std::char_traits<char>, Json::SecureAllocator<char> >
+#define JSONCPP_OSTREAM       std::basic_ostream<char, std::char_traits<char>>
+#define JSONCPP_ISTRINGSTREAM std::basic_istringstream<char, std::char_traits<char>, Json::SecureAllocator<char> >
+#define JSONCPP_ISTREAM       std::istream
+#else
 #define JSONCPP_STRING        std::string
 #define JSONCPP_OSTRINGSTREAM std::ostringstream
 #define JSONCPP_OSTREAM       std::ostream
 #define JSONCPP_ISTRINGSTREAM std::istringstream
 #define JSONCPP_ISTREAM       std::istream
+#endif // if JSON_USE_SECURE_MEMORY
 } // end namespace Json
 
 #endif // JSON_CONFIG_H_INCLUDED

include/json/reader.h

@@ -44,7 +44,7 @@ class JSON_API Reader {
   struct StructuredError {
     ptrdiff_t offset_start;
     ptrdiff_t offset_limit;
-    std::string message;
+    JSONCPP_STRING message;
   };
 
   /** \brief Constructs a Reader allowing all features
@@ -111,7 +111,7 @@ class JSON_API Reader {
    * \deprecated Use getFormattedErrorMessages() instead (typo fix).
    */
   JSONCPP_DEPRECATED("Use getFormattedErrorMessages() instead.")
-  std::string getFormatedErrorMessages() const;
+  JSONCPP_STRING getFormatedErrorMessages() const;
 
   /** \brief Returns a user friendly string that list errors in the parsed
    * document.
@@ -121,7 +121,7 @@ class JSON_API Reader {
    * occurred
    *         during parsing.
    */
-  std::string getFormattedErrorMessages() const;
+  JSONCPP_STRING getFormattedErrorMessages() const;
 
   /** \brief Returns a vector of structured erros encounted while parsing.
    * \return A (possibly empty) vector of StructuredError objects. Currently
@@ -138,7 +138,7 @@ class JSON_API Reader {
    * \return \c true if the error was successfully added, \c false if the
    * Value offset exceeds the document size.
    */
-  bool pushError(const Value& value, const std::string& message);
+  bool pushError(const Value& value, const JSONCPP_STRING& message);
 
   /** \brief Add a semantic error message with extra context.
    * \param value JSON Value location associated with the error
@@ -147,7 +147,7 @@ class JSON_API Reader {
    * \return \c true if the error was successfully added, \c false if either
    * Value offset exceeds the document size.
    */
-  bool pushError(const Value& value, const std::string& message, const Value& extra);
+  bool pushError(const Value& value, const JSONCPP_STRING& message, const Value& extra);
 
   /** \brief Return whether there are any errors.
    * \return \c true if there are no errors to report \c false if
@@ -183,7 +183,7 @@ class JSON_API Reader {
   class ErrorInfo {
   public:
     Token token_;
-    std::string message_;
+    JSONCPP_STRING message_;
     Location extra_;
   };
 
@@ -203,7 +203,7 @@ class JSON_API Reader {
   bool decodeNumber(Token& token);
   bool decodeNumber(Token& token, Value& decoded);
   bool decodeString(Token& token);
-  bool decodeString(Token& token, std::string& decoded);
+  bool decodeString(Token& token, JSONCPP_STRING& decoded);
   bool decodeDouble(Token& token);
   bool decodeDouble(Token& token, Value& decoded);
   bool decodeUnicodeCodePoint(Token& token,
@@ -214,30 +214,30 @@ class JSON_API Reader {
                                    Location& current,
                                    Location end,
                                    unsigned int& unicode);
-  bool addError(const std::string& message, Token& token, Location extra = 0);
+  bool addError(const JSONCPP_STRING& message, Token& token, Location extra = 0);
   bool recoverFromError(TokenType skipUntilToken);
-  bool addErrorAndRecover(const std::string& message,
+  bool addErrorAndRecover(const JSONCPP_STRING& message,
                           Token& token,
                           TokenType skipUntilToken);
   void skipUntilSpace();
   Value& currentValue();
   Char getNextChar();
   void
   getLocationLineAndColumn(Location location, int& line, int& column) const;
-  std::string getLocationLineAndColumn(Location location) const;
+  JSONCPP_STRING getLocationLineAndColumn(Location location) const;
   void addComment(Location begin, Location end, CommentPlacement placement);
   void skipCommentTokens(Token& token);
 
   typedef std::stack<Value*> Nodes;
   Nodes nodes_;
   Errors errors_;
-  std::string document_;
+  JSONCPP_STRING document_;
   Location begin_;
   Location end_;
   Location current_;
   Location lastValueEnd_;
   Value* lastValue_;
-  std::string commentsBefore_;
+  JSONCPP_STRING commentsBefore_;
   Features features_;
   bool collectComments_;
 };  // Reader
@@ -266,7 +266,7 @@ class JSON_API CharReader {
    */
   virtual bool parse(
       char const* beginDoc, char const* endDoc,
-      Value* root, std::string* errs) = 0;
+      Value* root, JSONCPP_STRING* errs) = 0;
 
   class JSON_API Factory {
   public:
@@ -286,7 +286,7 @@ class JSON_API CharReader {
   CharReaderBuilder builder;
   builder["collectComments"] = false;
   Value value;
-  std::string errs;
+  JSONCPP_STRING errs;
   bool ok = parseFromStream(builder, std::cin, &value, &errs);
 \endcode
 */
@@ -344,7 +344,7 @@ class JSON_API CharReaderBuilder : public CharReader::Factory {
 
   /** A simple way to update a specific setting.
    */
-  Value& operator[](std::string key);
+  Value& operator[](JSONCPP_STRING key);
 
   /** Called by ctor, but you can use this to reset settings_.
    * \pre 'settings' != NULL (but Json::null is fine)

include/json/value.h

@@ -323,6 +323,9 @@ Json::Value obj_value(Json::objectValue); // {}
   int compare(const Value& other) const;
 
   const char* asCString() const; ///< Embedded zeroes could cause you trouble!
+#if JSON_USE_SECURE_MEMORY
+  unsigned getCStringLength() const; //Allows you to understand the length of the CString
+#endif
   JSONCPP_STRING asString() const; ///< Embedded zeroes are possible.
   /** Get raw char* of string-value.
    *  \return false if !string. (Seg-fault if str or end are NULL.)