[PDFBOX-2781] Opening pdf document after encrypting it with PDFBox throws IllegalBlockSizeException

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.8.9, 1.8.10, 2.0.0
• Fix Version/s: 1.8.10, 2.0.0
• Component/s: Crypto, PDModel, Writing
• Environment: jdk 1.7.0_55, bouncy castle provider 1.52
• Assignee: Tilman Hausherr
• Reporter: Samuli Saarinen
• Created: 29/Apr/15 07:55
• Updated: 23/Jul/15 06:35
• Resolved: 29/Apr/15 19:30

Description

I'm trying to encrypt pdf document as per [1] like this:

PDDocument doc = PDDocument.loadNonSeq(getClass().getResourceAsStream("/testform_protected.pdf"), null);

int keyLength = 128; // 40 or 128; 256 will be available in version 2.0
AccessPermission ap = doc.getCurrentAccessPermission();

StandardProtectionPolicy spp = new StandardProtectionPolicy("12345", "", ap);
spp.setEncryptionKeyLength(keyLength);
spp.setPermissions(ap);
doc.protect(spp);

File outFile = new File("./target/testform_saved.pdf");

doc.save(outFile);
doc.close();

PDDocument loaded = PDDocument.loadNonSeq(outFile, null);

It works fine but opening the encrypted document with PDFBox (last line of above code) throws:

org.apache.pdfbox.exceptions.WrappedIOException
	at org.apache.pdfbox.pdmodel.encryption.SecurityHandler.encryptData(SecurityHandler.java:371)
	at org.apache.pdfbox.pdmodel.encryption.SecurityHandler.decryptString(SecurityHandler.java:577)
	at org.apache.pdfbox.pdfparser.NonSequentialPDFParser.decryptString(NonSequentialPDFParser.java:1571)
	at org.apache.pdfbox.pdfparser.NonSequentialPDFParser.decryptDictionary(NonSequentialPDFParser.java:1535)
	at org.apache.pdfbox.pdfparser.NonSequentialPDFParser.decrypt(NonSequentialPDFParser.java:1596)
	at org.apache.pdfbox.pdfparser.NonSequentialPDFParser.parseObjectDynamically(NonSequentialPDFParser.java:1460)
	at org.apache.pdfbox.pdfparser.NonSequentialPDFParser.parseObjectDynamically(NonSequentialPDFParser.java:1343)
	at org.apache.pdfbox.pdfparser.NonSequentialPDFParser.initialParse(NonSequentialPDFParser.java:383)
	at org.apache.pdfbox.pdfparser.NonSequentialPDFParser.parse(NonSequentialPDFParser.java:886)
	at org.apache.pdfbox.pdmodel.PDDocument.loadNonSeq(PDDocument.java:1273)
	at org.apache.pdfbox.pdmodel.PDDocument.loadNonSeq(PDDocument.java:1256)
	at com.remion.bronto.proex.pdf.PDFBoxEncryptionTest.testEncryptDecrypt(PDFBoxEncryptionTest.java:30)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:84)
	at org.testng.internal.Invoker.invokeMethod(Invoker.java:714)
	at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:901)
	at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1231)
	at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:127)
	at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:111)
	at org.testng.TestRunner.privateRun(TestRunner.java:767)
	at org.testng.TestRunner.run(TestRunner.java:617)
	at org.testng.SuiteRunner.runTest(SuiteRunner.java:334)
	at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:329)
	at org.testng.SuiteRunner.privateRun(SuiteRunner.java:291)
	at org.testng.SuiteRunner.run(SuiteRunner.java:240)
	at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
	at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
	at org.testng.TestNG.runSuitesSequentially(TestNG.java:1224)
	at org.testng.TestNG.runSuitesLocally(TestNG.java:1149)
	at org.testng.TestNG.run(TestNG.java:1057)
	at org.testng.remote.RemoteTestNG.run(RemoteTestNG.java:111)
	at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:204)
	at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:175)
Caused by: javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher
	at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:750)
	at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:676)
	at com.sun.crypto.provider.AESCipher.engineDoFinal(AESCipher.java:313)
	at javax.crypto.Cipher.doFinal(Cipher.java:1970)
	at org.apache.pdfbox.pdmodel.encryption.SecurityHandler.encryptData(SecurityHandler.java:351)
	... 35 more

Opening the saved document with Acrobat works fine.

[1] http://pdfbox.apache.org/1.8/cookbook/encryption.html