Automatically perform initialization when slunkcrypt_random_bytes() is called for the first time.

Makefile

@@ -39,6 +39,10 @@ else
   SUFFIX :=
 endif
 
+ifeq ($(filter %-mingw32 %-windows-gnu,$(MACHINE)),)
+  LDFLGS += -lpthread
+endif
+
 ifeq ($(STATIC),1)
   LDFLGS += -static
 endif

frontend/src/main.c

@@ -192,7 +192,7 @@ static int encrypt(const char* const passphrase, const CHR* const input_path, co
 	uint64_t nonce;
 	if (slunkcrypt_generate_nonce(&nonce) != SLUNKCRYPT_SUCCESS)
 	{
-		FPUTS(T("\n\nSlunkCrypt error: Failed to generate salt!\n\n"), stderr);
+		FPUTS(T("\n\nSlunkCrypt error: Failed to generate nonce!\n\n"), stderr);
 		goto  clean_up;
 	}
 
@@ -206,7 +206,7 @@ static int encrypt(const char* const passphrase, const CHR* const input_path, co
 	nonce = swap_bytes_u64(nonce);
 	if (fwrite(&nonce, sizeof(uint64_t), 1U, file_out) < 1U)
 	{
-		FPUTS(T("\n\nI/O error: Failed to write salt value!\n\n"), stderr);
+		FPUTS(T("\n\nI/O error: Failed to write nonce value!\n\n"), stderr);
 		goto clean_up;
 	}
 
@@ -338,7 +338,7 @@ static int decrypt(const char* const passphrase, const CHR* const input_path, co
 	uint64_t nonce;
 	if (fread(&nonce, sizeof(uint64_t), 1U, file_in) < 1U)
 	{
-		FPUTS(T("\n\nI/O error: Failed to read salt value!\n\n"), stderr);
+		FPUTS(T("\n\nI/O error: Failed to read nonce value!\n\n"), stderr);
 		goto clean_up;
 	}
 
@@ -470,7 +470,7 @@ static int run_test_case(const char *const message, const uint64_t checksum)
 	uint64_t nonce;
 	if (slunkcrypt_generate_nonce(&nonce) != SLUNKCRYPT_SUCCESS)
 	{
-		FPUTS(T("\n\nWhoops: Failed to generate salt!\n\n"), stderr);
+		FPUTS(T("\n\nWhoops: Failed to generate nonce!\n\n"), stderr);
 		return EXIT_FAILURE;
 	}
 
@@ -596,8 +596,6 @@ int MAIN(const int argc, CHR *const argv[])
 	FPRINTF(stderr, T("SlunkCrypt Utility (%") T(PRIstr) T("-%") T(PRIstr) T("), by LoRd_MuldeR <MuldeR2@GMX.de>\n"), OS_TYPE, CPU_ARCH);
 	FPRINTF(stderr, T("Using libSlunkCrypt v%u.%u.%u [%") T(PRIstr) T("]\n\n"), SLUNKCRYPT_VERSION_MAJOR, SLUNKCRYPT_VERSION_MINOR, SLUNKCRYPT_VERSION_PATCH, SLUNKCRYPT_BUILD);
 
-	slunkcrypt_startup();
-
 	/* ----------------------------------------------------- */
 	/* Parse arguments                                       */
 	/* ----------------------------------------------------- */
@@ -714,7 +712,6 @@ clean_up:
 		free(passphrase_buffer);
 	}
 
-	slunkcrypt_cleanup();
 	return result;
 }
 

libslunkcrypt/include/slunkcrypt.h

@@ -78,13 +78,7 @@ SLUNKCRYPT_API extern const char *const SLUNKCRYPT_BUILD;
 SLUNKCRYPT_API extern volatile int g_slunkcrypt_abort_flag;
 
 /*
- * Global (de)initialization routines
+ * Nonce generator
- */
-SLUNKCRYPT_API void slunkcrypt_startup(void);
-SLUNKCRYPT_API void slunkcrypt_cleanup(void);
-
-/*
- * Seed generator
  */
 SLUNKCRYPT_API int slunkcrypt_generate_nonce(uint64_t* const nonce);
 
@@ -110,10 +104,11 @@ SLUNKCRYPT_API int slunkcrypt_decrypt_inplace(const slunkcrypt_t context, uint8_
 /*
  * Auxiliary functions
  */
-SLUNKCRYPT_API int slunkcrypt_random_bytes(uint8_t* const buffer, const size_t length);
+SLUNKCRYPT_API size_t slunkcrypt_random_bytes(uint8_t* const buffer, const size_t length);
 SLUNKCRYPT_API void slunkcrypt_bzero(void* const ptr, const size_t length);
 
 #ifdef __cplusplus
 }
 #endif
 #endif
+

libslunkcrypt/src/junk.c

@@ -15,109 +15,81 @@
 #ifdef _WIN32
 #	define WIN32_LEAN_AND_MEAN 1
 #	include <Windows.h>
-#	define SCHED_YIELD() Sleep(1U)
-#	define COMPARE_AND_SWAP(PTR,OLD,NEW) InterlockedCompareExchange((PTR),(NEW),(OLD))
-#	define ATOMIC_STORE(PTR,VAL) InterlockedExchange((PTR),(VAL))
-#	if defined(SecureZeroMemory)
-#		define HAVE_SECURE_ZERO_MEMORY 1
-#	else
-#		define HAVE_SECURE_ZERO_MEMORY 0
-#	endif
-#	define HAVE_GETRANDOM 0
-#	define HAVE_EXPLICIT_BZERO 0
 #else
 #	include <unistd.h>
-#	include <sched.h>
+#	include <pthread.h>
-#	define SCHED_YIELD() sched_yield()
-#	if defined(__GNUC__) || defined(__clang__) || defined(__INTEL_COMPILER)
-#		define COMPARE_AND_SWAP(PTR,OLD,NEW) __sync_val_compare_and_swap((PTR),(OLD),(NEW))
-#		define ATOMIC_STORE(PTR,VAL) __atomic_store_n((PTR),(VAL),__ATOMIC_RELEASE)
-#	else
-#		define COMPARE_AND_SWAP(PTR,OLD,NEW) ((OLD))
-#		define ATOMIC_STORE(PTR,VAL) do { *(PTR) = (VAL); } while(0)
 #endif
+
+// ==========================================================================
+// One-time init
+// ==========================================================================
+
+#ifdef _WIN32
+#	define ONCE_TYPE volatile LONG
+#	define ONCE_INIT 0L
+#	define ONCE_FUNC win32_run_once
+#else
+#	define ONCE_TYPE pthread_once_t
+#	define ONCE_INIT PTHREAD_ONCE_INIT
+#	define ONCE_FUNC pthread_once
+#endif
+
+#ifdef _WIN32
+static void win32_run_once(ONCE_TYPE *const control, void (*init_routine)(void))
+{
+	LONG status;
+	while ((status = InterlockedCompareExchange(control, -1L, 0L)) != 0L)
+	{
+		if(status > 0L)
+		{
+			return; /*already initialized*/
+		}
+		SwitchToThread();
+	}
+	init_routine();
+	InterlockedExchange(control, 1L);
+}
+#endif
+
+// ==========================================================================
+// Random bytes
+// ==========================================================================
+
+#ifdef _WIN32
+#	define HAVE_GETRANDOM 0
+#else
 #	if defined(__GLIBC__) && (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 25)
 #		define HAVE_GETRANDOM 1
-#		define HAVE_EXPLICIT_BZERO 1
 #	elif defined(__FreeBSD__) && (__FreeBSD__ >= 12)
 #		define HAVE_GETRANDOM 1
-#		define HAVE_EXPLICIT_BZERO 1
-#	elif defined(__FreeBSD__) && (__FreeBSD__ >= 11)
-#		define HAVE_GETRANDOM 0
-#		define HAVE_EXPLICIT_BZERO 1
 #	else
 #		define HAVE_GETRANDOM 0
-#		define HAVE_EXPLICIT_BZERO 0
+#	endif
 #endif
 #if HAVE_GETRANDOM
 #	include <sys/random.h>
 #endif
-#endif
-
-// ==========================================================================
-// Critical sections
-// ==========================================================================
-
-static int enter_critsec(volatile long *const lock, const int flag)
-{
-	const long expected = flag ? 0L : 1L;
-	long status;
-	while ((status = COMPARE_AND_SWAP(lock, expected, -1L)) < 0L)
-	{
-		SCHED_YIELD();
-	}
-	return (status == expected);
-}
-
-static void leave_critsec(volatile long *const lock, const int flag)
-{
-	ATOMIC_STORE(lock, flag ? 1L : 0L);
-}
-
-// ==========================================================================
-// (De)Initialization
-// ==========================================================================
-
-static volatile long s_initialized = 0L;
 
+/* Global state */
+static ONCE_TYPE s_random_is_initialized = ONCE_INIT;
 #if defined(_WIN32)
-typedef BOOLEAN(WINAPI *genrandom_t)(void*, ULONG);
+typedef BOOLEAN(WINAPI *rtl_genrandom_t)(void *buffer, ULONG buff_size);
-static HMODULE s_advapi32 = NULL;
+static HMODULE s_dll_advapi32 = NULL;
-static genrandom_t s_genrandom = NULL;
+static rtl_genrandom_t s_rtl_genrandom = NULL;
 #elif !HAVE_GETRANDOM
 static const char *const DEV_RANDOM[] = { "/dev/urandom", "/dev/arandom", "/dev/random", NULL };
 static int s_random_fd = -1;
 #endif
 
-void slunkcrypt_startup(void)
+/* Close down CSRNG */
-{
+static void exit_random_source(void)
-	if (enter_critsec(&s_initialized, 1))
 {
 #if defined(_WIN32)
-		if ((s_advapi32 = LoadLibraryW(L"advapi32.dll")))
+	s_rtl_genrandom = NULL;
+	if (s_dll_advapi32)
 	{
-			s_genrandom = (genrandom_t)GetProcAddress(s_advapi32, "SystemFunction036");
+		FreeLibrary(s_dll_advapi32);
-		}
+		s_dll_advapi32 = NULL;
-#elif !HAVE_GETRANDOM
-		for (size_t i = 0U; (s_random_fd < 0) && DEV_RANDOM[i]; ++i)
-		{
-			s_random_fd = open(DEV_RANDOM[i], O_RDONLY);
-		}
-#endif
-		leave_critsec(&s_initialized, 1);
-	}
-}
-
-void slunkcrypt_cleanup(void)
-{
-	if (enter_critsec(&s_initialized, 0))
-	{
-#if defined(_WIN32)
-		s_genrandom = NULL;
-		if (s_advapi32)
-		{
-			FreeLibrary(s_advapi32);
-			s_advapi32 = NULL;
 	}
 #elif !HAVE_GETRANDOM
 	if (s_random_fd >= 0)
@@ -126,48 +98,72 @@ void slunkcrypt_cleanup(void)
 		s_random_fd = -1;
 	}
 #endif
-		leave_critsec(&s_initialized, 0);
-	}
 }
 
-// ==========================================================================
+/* Initialize CSRNG */
-// Auxiliary functions
+static void init_random_source(void)
-// ==========================================================================
-
-int slunkcrypt_random_bytes(uint8_t* const buffer, const size_t length)
 {
 #if defined(_WIN32)
-	if ((length <= ((size_t)ULONG_MAX)))
+	if ((s_dll_advapi32 = LoadLibraryW(L"advapi32.dll")))
 	{
-		if (s_genrandom)
+		s_rtl_genrandom = (rtl_genrandom_t)GetProcAddress(s_dll_advapi32, "SystemFunction036");
+	}
+#elif !HAVE_GETRANDOM
+	for (size_t i = 0U; DEV_RANDOM[i]; ++i)
 	{
-			return s_genrandom(buffer, (ULONG)length) ? 0 : (-1);
+		if ((s_random_fd = open(DEV_RANDOM[i], O_RDONLY)) >= 0)
+		{
+			break; /*success*/
 		}
 	}
-	return -1;
+#endif
+	atexit(exit_random_source);
+}
+
+/* Generate random bytes */
+size_t slunkcrypt_random_bytes(uint8_t* const buffer, const size_t length)
+{
+	ONCE_FUNC(&s_random_is_initialized, init_random_source);
+#if defined(_WIN32)
+	if (s_rtl_genrandom)
+	{
+		const ULONG buff_size = (ULONG)length;
+		return s_rtl_genrandom(buffer, buff_size) ? buff_size : 0U;
+	}
 #elif HAVE_GETRANDOM
-	if (getrandom(buffer, length, 0U) >= length)
+	const ssize_t result = getrandom(buffer, length, 0U);
-	{
+	return (result < 0) ? 0U : ((size_t)result);
-		return 0;
-	}
-	return -1;
 #else
 	if (s_random_fd >= 0)
 	{
-		if (read(s_random_fd, buffer, length) >= length)
+		const ssize_t result = read(s_random_fd, buffer, length);
-		{
+		return (result < 0) ? 0U : ((size_t)result);
-			return 0;
 	}
-	}
-	return -1;
 #endif
+	return 0U;
 }
 
+// ==========================================================================
+// Zero memory
+// ==========================================================================
+
+#ifdef _WIN32
+#	define HAVE_EXPLICIT_BZERO 0
+#else
+#	if defined(__GLIBC__) && (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 25)
+#		define HAVE_EXPLICIT_BZERO 1
+#	elif defined(__FreeBSD__) && (__FreeBSD__ >= 11)
+#		define HAVE_EXPLICIT_BZERO 1
+#	else
+#		define HAVE_EXPLICIT_BZERO 0
+#	endif
+#endif
+
 void slunkcrypt_bzero(void* const ptr, const size_t length)
 {
 	if ((ptr) && (length > 0U))
 	{
-#if HAVE_SECURE_ZERO_MEMORY
+#if defined(_WIN32) && defined(SecureZeroMemory)
 		SecureZeroMemory(ptr, length);
 #elif HAVE_EXPLICIT_BZERO
 		explicit_bzero(ptr, length);

libslunkcrypt/src/slunkcrypt.c

@@ -303,7 +303,7 @@ int slunkcrypt_generate_nonce(uint64_t* const nonce)
 	}
 	do
 	{
-		if (slunkcrypt_random_bytes((uint8_t*)nonce, sizeof(uint64_t)) != 0)
+		if (slunkcrypt_random_bytes((uint8_t*)nonce, sizeof(uint64_t)) != sizeof(uint64_t))
 		{
 			return SLUNKCRYPT_FAILURE;
 		}