From 28c37dbcf87665a4ccec58bef9ef8ff0697022dd Mon Sep 17 00:00:00 2001
From: Martin Kretzschmar <mkretzschmar@src.gnome.org>
Date: Mon, 31 Mar 2003 16:45:09 +0000
Subject: Import of Xpdf 2.00 for merge

---
(limited to 'pdf/xpdf/Decrypt.cc')

diff --git a/pdf/xpdf/Decrypt.cc b/pdf/xpdf/Decrypt.cc
index 8de4091..bb3e3f1 100644
--- a/pdf/xpdf/Decrypt.cc
+++ b/pdf/xpdf/Decrypt.cc
@@ -6,11 +6,12 @@
 //
 //========================================================================
 
-#ifdef __GNUC__
+#include <aconf.h>
+
+#ifdef USE_GCC_PRAGMAS
 #pragma implementation
 #endif
 
-#include <aconf.h>
 #include "gmem.h"
 #include "Decrypt.h"
 
@@ -65,11 +66,12 @@ GBool Decrypt::makeFileKey(int encVersion, int encRevision, int keyLength,
 			   int permissions, GString *fileID,
 			   GString *ownerPassword, GString *userPassword,
 			   Guchar *fileKey, GBool *ownerPasswordOk) {
-  Guchar test[32];
+  Guchar test[32], test2[32];
   GString *userPassword2;
   Guchar fState[256];
+  Guchar tmpKey[16];
   Guchar fx, fy;
-  int len, i;
+  int len, i, j;
 
   // try using the supplied owner password to generate the user password
   if (ownerPassword) {
@@ -89,12 +91,26 @@ GBool Decrypt::makeFileKey(int encVersion, int encRevision, int keyLength,
       md5(test, 16, test);
     }
   }
-  rc4InitKey(test, keyLength, fState);
-  fx = fy = 0;
-  for (i = 0; i < 32; ++i) {
-    test[i] = rc4DecryptByte(fState, &fx, &fy, ownerKey->getChar(i));
+  if (encRevision == 2) {
+    rc4InitKey(test, keyLength, fState);
+    fx = fy = 0;
+    for (i = 0; i < 32; ++i) {
+      test2[i] = rc4DecryptByte(fState, &fx, &fy, ownerKey->getChar(i));
+    }
+  } else {
+    memcpy(test2, ownerKey->getCString(), 32);
+    for (i = 19; i >= 0; --i) {
+      for (j = 0; j < keyLength; ++j) {
+	tmpKey[j] = test[j] ^ i;
+      }
+      rc4InitKey(tmpKey, keyLength, fState);
+      fx = fy = 0;
+      for (j = 0; j < 32; ++j) {
+	test2[j] = rc4DecryptByte(fState, &fx, &fy, test2[j]);
+      }
+    }
   }
-  userPassword2 = new GString((char *)test, 32);
+  userPassword2 = new GString((char *)test2, 32);
   if (makeFileKey2(encVersion, encRevision, keyLength, ownerKey, userKey,
 		   permissions, fileID, userPassword2, fileKey)) {
     *ownerPasswordOk = gTrue;
@@ -143,7 +159,7 @@ GBool Decrypt::makeFileKey2(int encVersion, int encRevision, int keyLength,
   md5(buf, 68 + fileID->getLength(), fileKey);
   if (encRevision == 3) {
     for (i = 0; i < 50; ++i) {
-      md5(fileKey, 16, fileKey);
+      md5(fileKey, keyLength, fileKey);
     }
   }
 
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