Fix constexpr issues under GCC 4.1.2 found on CentOS 5

misc.h

@@ -109,7 +109,9 @@
 #  define SIZE_MAX __SIZE_MAX__
 # elif defined(SIZE_T_MAX) && (SIZE_T_MAX > 0)
 #  define SIZE_MAX SIZE_T_MAX
-# else
+# elif defined(__SIZE_TYPE__)
+#  define SIZE_MAX (~(__SIZE_TYPE__)0)
+#else
 #  define SIZE_MAX ((std::numeric_limits<size_t>::max)())
 # endif
 #endif

secblock.h

@@ -515,7 +515,7 @@ public:
 #if defined(CRYPTOPP_CXX11) && !defined(CRYPTOPP_DOXYGEN_PROCESSING)
 	enum : size_type { ELEMS_MAX = A::ELEMS_MAX };
 #else
-	static const size_type ELEMS_MAX = A::ELEMS_MAX;
+	static const size_type ELEMS_MAX = SIZE_MAX/sizeof(T);
 #endif
 
 	//! \brief Construct a SecBlock with space for size elements.