Store and load the Nonce as well as the CRC checksum in a byte-order-agnostic way.

frontend/src/main.c

@@ -189,26 +189,27 @@ static int encrypt(const char* const passphrase, const CHR* const input_path, co
 	FPUTS(T("Encrypting file contents, please be patient... "), stderr);
 	fflush(stderr);
 
-	uint64_t salt;
+	uint64_t nonce;
-	if (slunkcrypt_generate_salt(&salt) != SLUNKCRYPT_SUCCESS)
+	if (slunkcrypt_generate_nonce(&nonce) != SLUNKCRYPT_SUCCESS)
 	{
 		FPUTS(T("\n\nSlunkCrypt error: Failed to generate salt!\n\n"), stderr);
 		goto  clean_up;
 	}
 
-	if (fwrite(&salt, sizeof(uint64_t), 1U, file_out) < 1U)
+	ctx = slunkcrypt_alloc(nonce, (const uint8_t*)passphrase, strlen(passphrase));
-	{
-		FPUTS(T("\n\nI/O error: Failed to write salt value!\n\n"), stderr);
-		goto clean_up;
-	}
-
-	ctx = slunkcrypt_alloc(salt, (const uint8_t*)passphrase, strlen(passphrase));
 	if (!ctx)
 	{
 		FPUTS(g_slunkcrypt_abort_flag ? T("\n\nProcess interrupted!\n\n") : T("\n\nSlunkCrypt error: Failed to initialize encryption!\n\n"), stderr);
 		goto clean_up;
 	}
 
+	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);
+		goto clean_up;
+	}
+
 	clock_t clk_now, clk_update = clock();
 	uint64_t crc_actual = CRC_INITIALIZER, bytes_read = 0U;
 	uint8_t buffer[BUFFER_SIZE];
@@ -261,7 +262,7 @@ static int encrypt(const char* const passphrase, const CHR* const input_path, co
 		goto clean_up;
 	}
 
-	crc_actual = crc64_finish(crc_actual);
+	crc_actual = swap_bytes_u64(crc64_finish(crc_actual));
 
 	const int status = slunkcrypt_encrypt_inplace(ctx, (uint8_t*)&crc_actual, sizeof(uint64_t));
 	if (status != SLUNKCRYPT_SUCCESS)
@@ -334,14 +335,14 @@ static int decrypt(const char* const passphrase, const CHR* const input_path, co
 	FPUTS(T("Decrypting file contents, please be patient... "), stderr);
 	fflush(stderr);
 
-	uint64_t salt;
+	uint64_t nonce;
-	if (fread(&salt, sizeof(uint64_t), 1U, file_in) < 1U)
+	if (fread(&nonce, sizeof(uint64_t), 1U, file_in) < 1U)
 	{
 		FPUTS(T("\n\nI/O error: Failed to read salt value!\n\n"), stderr);
 		goto clean_up;
 	}
 
-	ctx = slunkcrypt_alloc(salt, (const uint8_t*)passphrase, strlen(passphrase));
+	ctx = slunkcrypt_alloc(swap_bytes_u64(nonce), (const uint8_t*)passphrase, strlen(passphrase));
 	if (!ctx)
 	{
 		FPUTS(g_slunkcrypt_abort_flag ? T("\n\nProcess interrupted!\n\n") : T("\n\nSlunkCrypt error: Failed to initialize decryption!\n\n"), stderr);
@@ -417,6 +418,8 @@ static int decrypt(const char* const passphrase, const CHR* const input_path, co
 		goto  clean_up;
 	}
 
+	crc_expected = swap_bytes_u64(crc_expected);
+
 	FPRINTF(stderr, T("\b\b\b\b\b\b\b%5.1f%%\n\n"), 100.0);
 	fflush(stderr);
 
@@ -464,8 +467,8 @@ static int run_test_case(const char *const message, const uint64_t checksum)
 	const size_t length = strlen(message) + 1U;
 	slunkcrypt_t ctx = SLUNKCRYPT_NULL;
 
-	uint64_t salt;
+	uint64_t nonce;
-	if (slunkcrypt_generate_salt(&salt) != SLUNKCRYPT_SUCCESS)
+	if (slunkcrypt_generate_nonce(&nonce) != SLUNKCRYPT_SUCCESS)
 	{
 		FPUTS(T("\n\nWhoops: Failed to generate salt!\n\n"), stderr);
 		return EXIT_FAILURE;
@@ -485,7 +488,7 @@ static int run_test_case(const char *const message, const uint64_t checksum)
 		goto clean_up;
 	}
 
-	ctx = slunkcrypt_alloc(salt, (const uint8_t*)passphrase, strlen(passphrase));
+	ctx = slunkcrypt_alloc(nonce, (const uint8_t*)passphrase, strlen(passphrase));
 	if (!ctx)
 	{
 		FPUTS(g_slunkcrypt_abort_flag ? T("\n\nProcess interrupted!\n\n") : T("\n\nWhoops: Failed to initialize encoder!\n\n"), stderr);
@@ -505,7 +508,7 @@ static int run_test_case(const char *const message, const uint64_t checksum)
 		goto clean_up;
 	}
 
-	status = slunkcrypt_reset(ctx, salt, (const uint8_t*)passphrase, strlen(passphrase));
+	status = slunkcrypt_reset(ctx, nonce, (const uint8_t*)passphrase, strlen(passphrase));
 	if (status != SLUNKCRYPT_SUCCESS)
 	{
 		FPUTS((status == SLUNKCRYPT_ABORTED) ? T("\n\nProcess interrupted!\n\n") : T("\n\nWhoops: Failed to initialize decoder!\n\n"), stderr);

frontend/src/utils.c

@@ -16,6 +16,7 @@
 #include <sys/types.h>
 #include <signal.h>
 
+/* Platform support */
 #ifdef _WIN32
 #	include <Windows.h>
 #	include <io.h>
@@ -29,10 +30,6 @@
 #	ifndef _O_U8TEXT
 #		define _O_U8TEXT 0x40000
 #	endif
-#ifndef _DLL
-extern char    *const _acmdln;
-extern wchar_t *const _wcmdln;
-#endif
 #else
 #	if defined(__USE_LARGEFILE64) && (__USE_LARGEFILE64)
 #		define STAT_T struct stat64
@@ -44,6 +41,16 @@ extern wchar_t *const _wcmdln;
 #	define FILENO(X) fileno((X))
 #endif
 
+// ==========================================================================
+// Terminal initialization
+// ==========================================================================
+
+/* CRT imports */
+#if defined(_WIN32) && !defined(_DLL)
+extern char    *const _acmdln;
+extern wchar_t *const _wcmdln;
+#endif
+
 void init_terminal(void)
 {
 #ifdef _WIN32
@@ -57,6 +64,10 @@ void init_terminal(void)
 #endif
 }
 
+// ==========================================================================
+// Signal handling
+// ==========================================================================
+
 void setup_signal_handler(const int signo, signal_handler_t* const handler)
 {
 #ifdef _WIN32
@@ -70,6 +81,10 @@ void setup_signal_handler(const int signo, signal_handler_t* const handler)
 #endif
 }
 
+// ==========================================================================
+// Character set conversion
+// ==========================================================================
+
 char* CHR_to_utf8(const CHR*const input)
 {
 #ifdef _WIN32
@@ -101,6 +116,35 @@ char* CHR_to_utf8(const CHR*const input)
 #endif
 }
 
+// ==========================================================================
+// Byte-order support
+// ==========================================================================
+
+#if defined(__BYTE_ORDER) && defined(__BIG_ENDIAN) && (__BYTE_ORDER == __BIG_ENDIAN)
+#	define BIG_ENDIAN_BYTE_ORDER 1
+#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
+#	define BIG_ENDIAN_BYTE_ORDER 1
+#else
+#	define BIG_ENDIAN_BYTE_ORDER 0
+#endif
+
+uint64_t swap_bytes_u64(const uint64_t value)
+{
+#if BIG_ENDIAN_BYTE_ORDER
+	return
+		(((value) >> 56) & 0x00000000000000FF) | (((value) >> 40) & 0x000000000000FF00) |
+		(((value) >> 24) & 0x0000000000FF0000) | (((value) >>  8) & 0x00000000FF000000) |
+		(((value) <<  8) & 0x000000FF00000000) | (((value) << 24) & 0x0000FF0000000000) |
+		(((value) << 40) & 0x00FF000000000000) | (((value) << 56) & 0xFF00000000000000);
+#else
+	return value; /*nothing to do*/
+#endif
+}
+
+// ==========================================================================
+// File functions
+// ==========================================================================
+
 uint64_t get_file_size(FILE* const file)
 {
 	STAT_T stat;

frontend/src/utils.h

@@ -13,6 +13,7 @@ typedef void (signal_handler_t)(int);
 
 void init_terminal(void);
 void setup_signal_handler(const int signo, signal_handler_t* const handler);
+uint64_t swap_bytes_u64(const uint64_t value);
 char* CHR_to_utf8(const CHR *const input);
 uint64_t get_file_size(FILE* const file);
 const CHR *get_file_name(const CHR *path);