diff options
Diffstat (limited to 'src/java/org/apache/poi/poifs/crypt/CryptoFunctions.java')
| -rw-r--r-- | src/java/org/apache/poi/poifs/crypt/CryptoFunctions.java | 87 |
1 files changed, 79 insertions, 8 deletions
diff --git a/src/java/org/apache/poi/poifs/crypt/CryptoFunctions.java b/src/java/org/apache/poi/poifs/crypt/CryptoFunctions.java index f5f52b93f4..f9f970ade9 100644 --- a/src/java/org/apache/poi/poifs/crypt/CryptoFunctions.java +++ b/src/java/org/apache/poi/poifs/crypt/CryptoFunctions.java @@ -289,6 +289,12 @@ public class CryptoFunctions { 0x313E, 0x1872, 0xE139, 0xD40F, 0x84F9, 0x280C, 0xA96A,
0x4EC3
};
+
+ private static final byte PadArray[] = {
+ (byte)0xBB, (byte)0xFF, (byte)0xFF, (byte)0xBA, (byte)0xFF,
+ (byte)0xFF, (byte)0xB9, (byte)0x80, (byte)0x00, (byte)0xBE,
+ (byte)0x0F, (byte)0x00, (byte)0xBF, (byte)0x0F, (byte)0x00
+ };
private static final int EncryptionMatrix[][] = {
/* char 1 */ {0xAEFC, 0x4DD9, 0x9BB2, 0x2745, 0x4E8A, 0x9D14, 0x2A09},
@@ -309,20 +315,18 @@ public class CryptoFunctions { };
/**
- * This method generates the xored-hashed password for word documents < 2007.
+ * This method generates the xor verifier for word documents < 2007 (method 2).
* Its output will be used as password input for the newer word generations which
* utilize a real hashing algorithm like sha1.
*
- * Although the code was taken from the "see"-link below, this looks similar
- * to the method in [MS-OFFCRYPTO] 2.3.7.2 Binary Document XOR Array Initialization Method 1.
- *
- * @param password
+ * @param password the password
* @return the hashed password
*
+ * @see <a href="http://msdn.microsoft.com/en-us/library/dd905229.aspx">2.3.7.4 Binary Document Password Verifier Derivation Method 2</a>
* @see <a href="http://blogs.msdn.com/b/vsod/archive/2010/04/05/how-to-set-the-editing-restrictions-in-word-using-open-xml-sdk-2-0.aspx">How to set the editing restrictions in Word using Open XML SDK 2.0</a>
* @see <a href="http://www.aspose.com/blogs/aspose-blogs/vladimir-averkin/archive/2007/08/20/funny-how-the-new-powerful-cryptography-implemented-in-word-2007-turns-it-into-a-perfect-tool-for-document-password-removal.html">Funny: How the new powerful cryptography implemented in Word 2007 turns it into a perfect tool for document password removal.</a>
*/
- public static int xorHashPasswordAsInt(String password) {
+ public static int createXorVerifier2(String password) {
//Array to hold Key Values
byte[] generatedKey = new byte[4];
@@ -391,7 +395,7 @@ public class CryptoFunctions { * This method generates the xored-hashed password for word documents < 2007.
*/
public static String xorHashPassword(String password) {
- int hashedPassword = xorHashPasswordAsInt(password);
+ int hashedPassword = createXorVerifier2(password);
return String.format("%1$08X", hashedPassword);
}
@@ -400,7 +404,7 @@ public class CryptoFunctions { * processing in word documents 2007 and newer, which utilize a real hashing algorithm like sha1.
*/
public static String xorHashPasswordReversed(String password) {
- int hashedPassword = xorHashPasswordAsInt(password);
+ int hashedPassword = createXorVerifier2(password);
return String.format("%1$02X%2$02X%3$02X%4$02X"
, ( hashedPassword >>> 0 ) & 0xFF
@@ -409,4 +413,71 @@ public class CryptoFunctions { , ( hashedPassword >>> 24 ) & 0xFF
);
}
+
+ /**
+ * Create the verifier for xor obfuscation (method 1)
+ *
+ * @see <a href="http://msdn.microsoft.com/en-us/library/dd926947.aspx">2.3.7.1 Binary Document Password Verifier Derivation Method 1</a>
+ * @see <a href="http://msdn.microsoft.com/en-us/library/dd905229.aspx">2.3.7.4 Binary Document Password Verifier Derivation Method 2</a>
+ *
+ * @param password the password
+ * @return the verifier
+ */
+ public static int createXorVerifier1(String password) {
+ // the verifier for method 1 is part of the verifier for method 2
+ // so we simply chop it from there
+ return createXorVerifier2(password) & 0xFFFF;
+ }
+
+ /**
+ * Create the xor key for xor obfuscation, which is used to create the xor array (method 1)
+ *
+ * @see <a href="http://msdn.microsoft.com/en-us/library/dd924704.aspx">2.3.7.2 Binary Document XOR Array Initialization Method 1</a>
+ * @see <a href="http://msdn.microsoft.com/en-us/library/dd905229.aspx">2.3.7.4 Binary Document Password Verifier Derivation Method 2</a>
+ *
+ * @param password the password
+ * @return the xor key
+ */
+ public static int createXorKey1(String password) {
+ // the xor key for method 1 is part of the verifier for method 2
+ // so we simply chop it from there
+ return createXorVerifier2(password) >>> 16;
+ }
+
+ /**
+ * Creates an byte array for xor obfuscation (method 1)
+ *
+ * @see <a href="http://msdn.microsoft.com/en-us/library/dd924704.aspx">2.3.7.2 Binary Document XOR Array Initialization Method 1</a>
+ * @see <a href="http://docs.libreoffice.org/oox/html/binarycodec_8cxx_source.html">Libre Office implementation</a>
+ *
+ * @param password the password
+ * @return the byte array for xor obfuscation
+ */
+ public static byte[] createXorArray1(String password) {
+ if (password.length() > 15) password = password.substring(0, 15);
+ byte passBytes[] = password.getBytes(Charset.forName("ASCII"));
+
+ // this code is based on the libre office implementation.
+ // The MS-OFFCRYPTO misses some infos about the various rotation sizes
+ byte obfuscationArray[] = new byte[16];
+ System.arraycopy(passBytes, 0, obfuscationArray, 0, passBytes.length);
+ System.arraycopy(PadArray, 0, obfuscationArray, passBytes.length, PadArray.length-passBytes.length+1);
+
+ int xorKey = createXorKey1(password);
+
+ // rotation of key values is application dependent
+ int nRotateSize = 2; /* Excel = 2; Word = 7 */
+
+ byte baseKeyLE[] = { (byte)(xorKey & 0xFF), (byte)((xorKey >>> 8) & 0xFF) };
+ for (int i=0; i<obfuscationArray.length; i++) {
+ obfuscationArray[i] ^= baseKeyLE[i&1];
+ obfuscationArray[i] = rotateLeft(obfuscationArray[i], nRotateSize);
+ }
+
+ return obfuscationArray;
+ }
+
+ private static byte rotateLeft(byte bits, int shift) {
+ return (byte)(((bits & 0xff) << shift) | ((bits & 0xff) >>> (8 - shift)));
+ }
}
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