Do not fail if an empty password is provided

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1907446 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 23 insertions, 1 deletions

diff --git a/poi/src/main/java/org/apache/poi/poifs/crypt/CryptoFunctions.java b/poi/src/main/java/org/apache/poi/poifs/crypt/CryptoFunctions.java
index 4a8883597b..28babc0c0f 100644
--- a/poi/src/main/java/org/apache/poi/poifs/crypt/CryptoFunctions.java
+++ b/poi/src/main/java/org/apache/poi/poifs/crypt/CryptoFunctions.java
@@ -538,7 +538,11 @@ public final class CryptoFunctions {
         // 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(PAD_ARRAY, 0, obfuscationArray, passBytes.length, PAD_ARRAY.length-passBytes.length+1);
+        if (passBytes.length == 0) {
+            System.arraycopy(PAD_ARRAY, 0, obfuscationArray, passBytes.length, PAD_ARRAY.length);
+        } else {
+            System.arraycopy(PAD_ARRAY, 0, obfuscationArray, passBytes.length, PAD_ARRAY.length - passBytes.length + 1);
+        }
 
         int xorKey = createXorKey1(password);
 
diff --git a/poi/src/test/java/org/apache/poi/poifs/crypt/TestXorEncryption.java b/poi/src/test/java/org/apache/poi/poifs/crypt/TestXorEncryption.java
index 3250bc0307..47e32ae4be 100644
--- a/poi/src/test/java/org/apache/poi/poifs/crypt/TestXorEncryption.java
+++ b/poi/src/test/java/org/apache/poi/poifs/crypt/TestXorEncryption.java
@@ -32,6 +32,7 @@ import org.apache.poi.hssf.record.crypto.Biff8EncryptionKey;
 import org.apache.poi.hssf.usermodel.HSSFSheet;
 import org.apache.poi.hssf.usermodel.HSSFWorkbook;
 import org.apache.poi.poifs.filesystem.POIFSFileSystem;
+import org.apache.poi.util.HexDump;
 import org.apache.poi.util.HexRead;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
@@ -54,6 +55,23 @@ class TestXorEncryption {
     }
 
     @Test
+    void testXorEncryptionEmptyPassword() {
+        // Xor-Password: ""
+        // 2.5.343 XORObfuscation
+        // key = 0
+        // verifier = 0
+        int verifier = CryptoFunctions.createXorVerifier1("");
+        int key = CryptoFunctions.createXorKey1("");
+        assertEquals(0, key);
+        assertEquals(0, verifier);
+
+        byte[] xorArrAct = CryptoFunctions.createXorArray1("");
+        byte[] xorArrExp = HexRead.readFromString("EE-FF-FF-EA-FF-FF-E6-02-00-FA-3C-00-FE-3C-00-00");
+        assertThat("Having: " + HexDump.dump(xorArrAct, 0, 0),
+                xorArrExp, equalTo(xorArrAct));
+    }
+
+    @Test
     void testUserFile() throws IOException {
         File f = getSampleFile("xor-encryption-abc.xls");
         Biff8EncryptionKey.setCurrentUserPassword("abc");