1 files changed, 94 insertions, 0 deletions
diff --git a/Common/Cache.c b/Common/Cache.c
new file mode 100644
index 0000000..5b4b754
--- /dev/null
+++ b/Common/Cache.c
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+/*
+ Legal Notice: Some portions of the source code contained in this file were
+ derived from the source code of Encryption for the Masses 2.02a, which is
+ Copyright (c) 1998-2000 Paul Le Roux and which is governed by the 'License
+ Agreement for Encryption for the Masses'. Modifications and additions to
+ the original source code (contained in this file) and all other portions
+ of this file are Copyright (c) 2003-2008 TrueCrypt Developers Association
+ and are 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 "Crypto.h"
+#include "Fat.h"
+#include "Volumes.h"
+#include "Apidrvr.h"
+#include "Common.h"
+#include "Cache.h"
+
+Password CachedPasswords[CACHE_SIZE];
+int cacheEmpty = 1;
+static int nPasswordIdx = 0;
+
+int ReadVolumeHeaderWCache (BOOL bBoot, BOOL bCache, char *header, Password *password, PCRYPTO_INFO *retInfo)
+{
+	int nReturnCode = ERR_PASSWORD_WRONG;
+	int i;
+
+	/* Attempt to recognize volume using mount password */
+	if (password->Length > 0)
+	{
+		nReturnCode = ReadVolumeHeader (bBoot, header, password, retInfo, NULL);
+
+		/* Save mount passwords back into cache if asked to do so */
+		if (bCache && (nReturnCode == 0 || nReturnCode == ERR_CIPHER_INIT_WEAK_KEY))
+		{
+			for (i = 0; i < CACHE_SIZE; i++)
+			{
+				if (memcmp (&CachedPasswords[i], password, sizeof (Password)) == 0)
+					break;
+			}
+
+			if (i == CACHE_SIZE)
+			{
+				/* Store the password */
+				CachedPasswords[nPasswordIdx] = *password;
+
+				/* Try another slot */
+				nPasswordIdx = (nPasswordIdx + 1) % CACHE_SIZE;
+
+				cacheEmpty = 0;
+			}
+		}
+	}
+	else if (!cacheEmpty)
+	{
+		/* Attempt to recognize volume using cached passwords */
+		for (i = 0; i < CACHE_SIZE; i++)
+		{
+			if (CachedPasswords[i].Length > 0)
+			{
+				nReturnCode = ReadVolumeHeader (bBoot, header, &CachedPasswords[i], retInfo, NULL);
+
+				if (nReturnCode != ERR_PASSWORD_WRONG)
+					break;
+			}
+		}
+	}
+
+	return nReturnCode;
+}
+
+
+void AddPasswordToCache (Password *password)
+{
+	int i;
+	for (i = 0; i < CACHE_SIZE; i++)
+	{
+		if (memcmp (&CachedPasswords[i], password, sizeof (Password)) == 0)
+			return;
+	}
+
+	CachedPasswords[nPasswordIdx] = *password;
+	nPasswordIdx = (nPasswordIdx + 1) % CACHE_SIZE;
+	cacheEmpty = 0;
+}
+
+
+void WipeCache ()
+{
+	burn (CachedPasswords, sizeof (CachedPasswords));
+	nPasswordIdx = 0;
+	cacheEmpty = 1;
+}