Add ossig.h. Move SignalHandler to ossig.h

This avoids a circular dependency between misc.h and trap.h. It also allows us to logically segregate and group code to replace C++ handlers, like set_terminate

misc.h

@@ -114,13 +114,13 @@ NAMESPACE_BEGIN(CryptoPP)
 // Forward declaration for IntToString specialization
 class Integer;
 
-// ************** compile-time CRYPTOPP_ASSERTion ***************
+// ************** compile-time assertion ***************
 
 #if CRYPTOPP_DOXYGEN_PROCESSING
 //! \brief Compile time CRYPTOPP_ASSERTion
 //! \param expr the expression to evaluate
 //! \details Asserts the expression expr though a dummy struct.
-#define CRYPTOPP_COMPILE_ASSERT(expr) ...
+#define CRYPTOPP_COMPILE_ASSERT(expr) { ... }
 #else // CRYPTOPP_DOXYGEN_PROCESSING
 template <bool b>
 struct CompileAssert
@@ -331,88 +331,6 @@ const T & Singleton<T, F, instance>::Ref(CRYPTOPP_NOINLINE_DOTDOTDOT) const
 }
 #endif
 
-#if defined(CRYPTOPP_BSD_AVAILABLE) || defined(CRYPTOPP_UNIX_AVAILABLE) || defined(CRYPTOPP_DOXYGEN_PROCESSING)
-//! \brief Signal handler function pointer
-//! \sa SignalHandler
-extern "C" {
-	typedef void (*SignalHandlerFn) (int);
-};
-
-//! Signal handler for Linux and Unix compatibles
-//! \tparam S Signal number
-//! \tparam O Flag indicating exsting handler should be overwriiten
-//! \details SignalHandler() can be used to install a signal handler with the signature
-//!   <tt>void handler_fn(int)</tt>. If <tt>SignalHandlerFn</tt> is not <tt>NULL</tt>, then
-//!   the sigaction is set to the function and the sigaction flags is set to the flags.
-//!   If <tt>SignalHandlerFn</tt> is <tt>NULL</tt>, then a default handler is installed
-//!   using sigaction flags set to 0. The default handler only returns from the call.
-//! \details Upon destruction the previous signal handler is restored.
-//! \warning Do not use SignalHandler in a code block that uses <tt>setjmp</tt> or <tt>longjmp</tt>
-//!   because the destructor may not run.
-//! \since Crypto++ 5.6.5
-//! \sa SignalHandlerFn, \ref CRYPTOPP_ASSERT "CRYPTOPP_ASSERT", DebugTrapHandler
-template <int S, bool O=false>
-struct SignalHandler : private NotCopyable
-{
-	//! \brief Construct a signal handler
-	//! \param pfn Pointer to a signal handler function
-	//! \param flags Flags to use with the signal handler
-	//! \details SignalHandler() installs a signal handler with the signature
-	//!   <tt>void handler_fn(int)</tt>. If <tt>SignalHandlerFn</tt> is not <tt>NULL</tt>, then
-	//!   the sigaction is set to the function and the sigaction flags is set to the flags.
-	//!   If <tt>SignalHandlerFn</tt> is <tt>NULL</tt>, then a default handler is installed
-	//!   using sigaction flags set to 0. The default handler only returns from the call.
-	//! \details Upon destruction the previous signal handler is restored.
-	//! \warning Do not use SignalHandler in a code block that uses <tt>setjmp</tt> or <tt>longjmp</tt>
-	//!   because the destructor may not run.
-	//! \since Crypto++ 5.6.5
-    SignalHandler(SignalHandlerFn pfn = 0, int flags = 0) : m_installed(false)
-	{
-		// http://pubs.opengroup.org/onlinepubs/007908799/xsh/sigaction.html
-		struct sigaction new_handler;
-		// memset(&new_handler, 0x00, sizeof(new_handler));
-
-		do
-		{
-			int ret = 0;
-
-			ret = sigaction (S, 0, &m_old);
-			if (ret != 0) break; // Failed
-
-			// Don't step on another's handler if Overwrite=false
-			if (m_old.sa_handler != 0 && !O) break;
-
-			// Set up the structure to specify the action.
-			new_handler.sa_handler = (pfn ? pfn : &SignalHandler::NullHandler);
-			new_handler.sa_flags = (pfn ? flags : 0);
-
-            ret = sigemptyset (&new_handler.sa_mask);
-            if (ret != 0) break; // Failed
-
-            // Install it
-            ret = sigaction (S, &new_handler, 0);
-            if (ret != 0) break; // Failed
-
-			m_installed = true;
-
-        } while(0);
-    }
-
-	~SignalHandler()
-	{
-		if (m_installed)
-			sigaction (S, &m_old, 0);
-	}
-
-private:
-
-	struct sigaction m_old;
-	bool m_installed;
-
-	static void NullHandler(int /*unused*/) { }
-};
-#endif
-
 // ************** misc functions ***************
 
 #if (!__STDC_WANT_SECURE_LIB__ && !defined(_MEMORY_S_DEFINED)) || defined(CRYPTOPP_WANT_SECURE_LIB)

ossig.h

@@ -0,0 +1,112 @@
+// ossig.h - written and placed in the public domain by Jeffrey Walton
+//           Copyright assigned to Crypto++ project.
+
+//! \file ossig.h
+//! \brief Utility class for trapping OS signals.
+//! \since Crypto++ 5.6.5
+
+#ifndef CRYPTOPP_OS_SIGNAL_H
+#define CRYPTOPP_OS_SIGNAL_H
+
+#include "config.h"
+
+#if defined(CRYPTOPP_BSD_AVAILABLE) || defined(CRYPTOPP_UNIX_AVAILABLE)
+# include <signal.h>
+#endif
+
+NAMESPACE_BEGIN(CryptoPP)
+
+// ************** Unix and Linux compatibles ***************
+
+#if defined(CRYPTOPP_BSD_AVAILABLE) || defined(CRYPTOPP_UNIX_AVAILABLE) || defined(CRYPTOPP_DOXYGEN_PROCESSING)
+//! \brief Signal handler function pointer
+//! \sa SignalHandler
+extern "C" {
+    typedef void (*SignalHandlerFn) (int);
+};
+
+//! Signal handler for Linux and Unix compatibles
+//! \tparam S Signal number
+//! \tparam O Flag indicating exsting handler should be overwriiten
+//! \details SignalHandler() can be used to install a signal handler with the signature
+//!   <tt>void handler_fn(int)</tt>. If <tt>SignalHandlerFn</tt> is not <tt>NULL</tt>, then
+//!   the sigaction is set to the function and the sigaction flags is set to the flags.
+//!   If <tt>SignalHandlerFn</tt> is <tt>NULL</tt>, then a default handler is installed
+//!   using sigaction flags set to 0. The default handler only returns from the call.
+//! \details Upon destruction the previous signal handler is restored if the former signal handler
+//!   was replaced.
+//! \warning Do not use SignalHandler in a code block that uses <tt>setjmp</tt> or <tt>longjmp</tt>
+//!   because the destructor may not run.
+//! \since Crypto++ 5.6.5
+//! \sa SignalHandlerFn, \ref CRYPTOPP_ASSERT "CRYPTOPP_ASSERT", DebugTrapHandler
+template <int S, bool O=false>
+struct SignalHandler
+{
+    //! \brief Construct a signal handler
+    //! \param pfn Pointer to a signal handler function
+    //! \param flags Flags to use with the signal handler
+    //! \details SignalHandler() installs a signal handler with the signature
+    //!   <tt>void handler_fn(int)</tt>. If <tt>SignalHandlerFn</tt> is not <tt>NULL</tt>, then
+    //!   the sigaction is set to the function and the sigaction flags is set to the flags.
+    //!   If <tt>SignalHandlerFn</tt> is <tt>NULL</tt>, then a default handler is installed
+    //!   using sigaction flags set to 0. The default handler only returns from the call.
+    //! \details Upon destruction the previous signal handler is restored if the former signal handler
+    //!   was overwritten.
+    //! \warning Do not use SignalHandler in a code block that uses <tt>setjmp</tt> or <tt>longjmp</tt>
+    //!   because the destructor may not run. <tt>setjmp</tt> is why cpu.cpp does not use SignalHandler
+    //!   during CPU feature testing.
+    //! \since Crypto++ 5.6.5
+    SignalHandler(SignalHandlerFn pfn = 0, int flags = 0) : m_installed(false)
+    {
+        // http://pubs.opengroup.org/onlinepubs/007908799/xsh/sigaction.html
+        struct sigaction new_handler;
+        // memset(&new_handler, 0x00, sizeof(new_handler));
+
+        do
+        {
+            int ret = 0;
+
+            ret = sigaction (S, 0, &m_old);
+            if (ret != 0) break; // Failed
+
+            // Don't step on another's handler if Overwrite=false
+            if (m_old.sa_handler != 0 && !O) break;
+
+            // Set up the structure to specify the action.
+            new_handler.sa_handler = (pfn ? pfn : &SignalHandler::NullHandler);
+            new_handler.sa_flags = (pfn ? flags : 0);
+
+            ret = sigemptyset (&new_handler.sa_mask);
+            if (ret != 0) break; // Failed
+
+            // Install it
+            ret = sigaction (S, &new_handler, 0);
+            if (ret != 0) break; // Failed
+
+            m_installed = true;
+
+        } while(0);
+    }
+
+    ~SignalHandler()
+    {
+        if (m_installed)
+            sigaction (S, &m_old, 0);
+    }
+
+private:
+    struct sigaction m_old;
+    bool m_installed;
+
+    static void NullHandler(int /*unused*/) { /* continue*/ }
+
+private:
+    // Not copyable
+    SignalHandler(const SignalHandler &);
+    void operator=(const SignalHandler &);
+};
+#endif
+
+NAMESPACE_END
+
+#endif // CRYPTOPP_OS_SIGNAL_H

test.cpp

@@ -21,6 +21,7 @@
 #include "whrlpool.h"
 #include "tiger.h"
 #include "smartptr.h"
+#include "ossig.h"
 #include "trap.h"
 
 #include "validate.h"
@@ -132,6 +133,7 @@ RandomNumberGenerator & GlobalRNG()
 // See misc.h and trap.h for comments and usage
 #if CRYPTOPP_DEBUG && (defined(CRYPTOPP_BSD_AVAILABLE) || defined(CRYPTOPP_UNIX_AVAILABLE))
 static const SignalHandler<SIGTRAP, false> s_dummyHandler;
+// static const DebugTrapHandle s_dummyHandler;
 #endif
 
 int CRYPTOPP_API main(int argc, char *argv[])

trap.h

@@ -17,6 +17,7 @@
 #define CRYPTOPP_TRAP_H
 
 #include "config.h"
+#include "ossig.h"
 
 #if CRYPTOPP_DEBUG
 #  include <iostream>
@@ -24,8 +25,6 @@
 #  if defined(CRYPTOPP_WIN32_AVAILABLE)
 #    define WIN32_LEAN_AND_MEAN
 #    include <Windows.h>
-#  elif defined(CRYPTOPP_BSD_AVAILABLE) || defined(CRYPTOPP_UNIX_AVAILABLE)
-#    include <signal.h>
 #  endif
 #endif // CRYPTOPP_DEBUG
 
@@ -131,46 +130,14 @@ NAMESPACE_BEGIN(CryptoPP)
 //! \since Crypto++ 5.6.5
 //! \sa \ref CRYPTOPP_ASSERT "CRYPTOPP_ASSERT", SignalHandler, <A HREF="http://github.com/weidai11/cryptopp/issues/277">Issue 277</A>,
 //!   <A HREF="http://seclists.org/oss-sec/2016/q3/520">CVE-2016-7420</A>
-struct DebugTrapHandler
-{
-    DebugTrapHandler()
-    {
-        // http://pubs.opengroup.org/onlinepubs/007908799/xsh/sigaction.html
-        struct sigaction old_handler, new_handler;
-        memset(&old_handler, 0x00, sizeof(old_handler));
-		memset(&new_handler, 0x00, sizeof(new_handler));
 
-        do
+#if defined(CRYPTOPP_DOXYGEN_PROCESSING)
-        {
+class DebugTrapHandler : public SignalHandler<SIGILL, false> { };
-            int ret = 0;
+#else
+typedef SignalHandler<SIGILL, false> DebugTrapHandler;
+#endif
 
-            ret = sigaction (SIGTRAP, 0, &old_handler);
+#endif  // Linux, Unix and Documentation
-            if (ret != 0) break; // Failed
-
-            // Don't step on another's handler
-            if (old_handler.sa_handler != 0) break;
-
-            // Set up the structure to specify the NULL action.
-            new_handler.sa_handler = &DebugTrapHandler::NullHandler;
-            new_handler.sa_flags = 0;
-
-            ret = sigemptyset (&new_handler.sa_mask);
-            if (ret != 0) break; // Failed
-
-            // Install it
-            ret = sigaction (SIGTRAP, &new_handler, 0);
-            if (ret != 0) break; // Failed
-
-        } while(0);
-    }
-
-    static void NullHandler(int /*unused*/) { }
-
-private:
-    DebugTrapHandler(const DebugTrapHandler &);
-    void operator=(const DebugTrapHandler &);
-};
-#endif  // DebugTrapHandler
 
 NAMESPACE_END