correct required base64 buffer size

Base.cpp

@@ -190,6 +190,13 @@ namespace data
 		return outCount;
 	}
 
+	size_t Base64EncodingBufferSize (const size_t input_size) 
+	{
+		auto d = div (input_size, 3);
+		if (d.rem) d.quot++;
+		return 4*d.quot;
+	}
+	
 	/*
 	*
 	* iT64
@@ -328,13 +335,6 @@ namespace data
 			return 0;
 		}	
 	}
-
-	// from https://stackoverflow.com/questions/1533113/calculate-the-size-to-a-base-64-encoded-message
-	size_t Base64EncodingBufferSize(const size_t input_size) {
-		const size_t code_size		= ((input_size * 4) / 3);
-		const size_t padding_size = (input_size % 3) ? (3 - (input_size % 3)) : 0;
-		return code_size + padding_size;
-	}
 }
 }