Add original TrueCrypt 7.1a sources

src/Common/Wipe.c

@@ -0,0 +1,187 @@
+/*
+ Copyright (c) 2008-2009 TrueCrypt Developers Association. All rights reserved.
+
+ Governed by the TrueCrypt License 3.0 the full text of which is contained in
+ the file License.txt included in TrueCrypt binary and source code distribution
+ packages.
+*/
+
+#include "Tcdefs.h"
+#include "Wipe.h"
+
+
+static BOOL Wipe1PseudoRandom (int pass, byte *buffer, size_t size)
+{
+	return FALSE;
+}
+
+
+// Fill buffer with wipe patterns defined in "National Industrial Security Program Operating Manual", US DoD 5220.22-M.
+// Return: FALSE = buffer must be filled with random data
+
+static BOOL Wipe3Dod5220 (int pass, byte *buffer, size_t size)
+{
+	byte wipeChar;
+
+	switch (pass)
+	{
+	case 1:
+		wipeChar = 0;
+		break;
+
+	case 2:
+		wipeChar = 0xff;
+		break;
+
+	default:
+		return FALSE;
+	}
+
+	memset (buffer, wipeChar, size);
+	return TRUE;
+}
+
+
+static BOOL Wipe7Dod5220 (int pass, byte randChars[TC_WIPE_RAND_CHAR_COUNT], byte *buffer, size_t size)
+{
+	byte wipeChar;
+
+	switch (pass)
+	{
+	case 1:
+		wipeChar = randChars[0];
+		break;
+
+	case 2:
+		wipeChar = ~randChars[0];
+		break;
+
+	case 4:
+		wipeChar = randChars[1];
+		break;
+
+	case 5:
+		wipeChar = randChars[2];
+		break;
+
+	case 6:
+		wipeChar = ~randChars[2];
+		break;
+
+	default:
+		return FALSE;
+	}
+
+	memset (buffer, wipeChar, size);
+	return TRUE;
+}
+
+
+// Fill the buffer with wipe patterns defined in the paper "Secure Deletion of Data from Magnetic and Solid-State Memory" by Peter Gutmann.
+// Return: FALSE = buffer must be filled with random data
+
+static BOOL Wipe35Gutmann (int pass, byte *buffer, size_t size)
+{
+	byte wipePat3[] = { 0x92, 0x49, 0x24 };
+	int wipePat3Pos;
+	size_t i;
+
+	switch (pass)
+	{
+	case 5:
+		memset (buffer, 0x55, size);
+		break;
+
+	case 6:
+		memset (buffer, 0xaa, size);
+		break;
+
+	case 7:
+	case 26:
+	case 29:
+		wipePat3Pos = 0;
+		goto wipe3;
+
+	case 8:
+	case 27:
+	case 30:
+		wipePat3Pos = 1;
+		goto wipe3;
+
+	case 9:
+	case 28:
+	case 31:
+		wipePat3Pos = 2;
+		goto wipe3;
+
+wipe3:
+		if (pass >= 29)
+		{
+			wipePat3[0] = ~wipePat3[0];
+			wipePat3[1] = ~wipePat3[1];
+			wipePat3[2] = ~wipePat3[2];
+		}
+
+		for (i = 0; i < size; ++i)
+		{
+			buffer[i] = wipePat3[wipePat3Pos++ % 3];
+		}
+		break;
+
+	default:
+		if (pass >= 10 && pass <= 25)
+			memset (buffer, (pass - 10) * 0x11, size);
+		else
+			return FALSE;
+	}
+
+	return TRUE;
+}
+
+
+int GetWipePassCount (WipeAlgorithmId algorithm)
+{
+	switch (algorithm)
+	{
+	case TC_WIPE_1_RAND:
+		return 1;
+
+	case TC_WIPE_3_DOD_5220:
+		return 3;
+
+	case TC_WIPE_7_DOD_5220:
+		return 7;
+
+	case TC_WIPE_35_GUTMANN:
+		return 35;
+
+	default:
+		TC_THROW_FATAL_EXCEPTION;
+	}
+
+	return 0;	// Prevent compiler warnings
+}
+
+
+BOOL WipeBuffer (WipeAlgorithmId algorithm, byte randChars[TC_WIPE_RAND_CHAR_COUNT], int pass, byte *buffer, size_t size)
+{
+	switch (algorithm)
+	{
+	case TC_WIPE_1_RAND:
+		return Wipe1PseudoRandom (pass, buffer, size);
+
+	case TC_WIPE_3_DOD_5220:
+		return Wipe3Dod5220 (pass, buffer, size);
+
+	case TC_WIPE_7_DOD_5220:
+		return Wipe7Dod5220 (pass, randChars, buffer, size);
+
+	case TC_WIPE_35_GUTMANN:
+		return Wipe35Gutmann (pass, buffer, size);
+
+	default:
+		TC_THROW_FATAL_EXCEPTION;
+	}
+
+	return FALSE;	// Prevent compiler warnings
+}