bug: pdfs might have padded us. didnt consider that wonderful option (#306)

Author: galkahana

PDFWriter/DecryptionHelper.cpp

@@ -150,13 +150,21 @@ EStatusCode DecryptionHelper::Setup(PDFParser* inParser, const string& inPasswor
 			mRevision = (unsigned int)revisionHelper.GetAsInteger();
 		}
 
+		size_t ouLength = mRevision <= 4 ? 32 : 48; // R <= 4 is 32 bytes, R >= 5 is 48 bytes
+		size_t oEuELength = 32;
+
 		RefCountPtr<PDFObject> o(inParser->QueryDictionaryObject(encryptionDictionary.GetPtr(), "O"));
 		if (!o) {
 			break;
 		}
 		else {
 			ParsedPrimitiveHelper oHelper(o.GetPtr());
 			mO = stringToByteList(oHelper.ToString());
+			if(mO.size() > ouLength) {
+				// some wiseasses might use longer value then expected and this causes trouble with auth. trim.
+				mO = substr(mO, 0, ouLength);
+			}
+
 		}
 
 		RefCountPtr<PDFObject> u(inParser->QueryDictionaryObject(encryptionDictionary.GetPtr(), "U"));
@@ -166,6 +174,10 @@ EStatusCode DecryptionHelper::Setup(PDFParser* inParser, const string& inPasswor
 		else {
 			ParsedPrimitiveHelper uHelper(u.GetPtr());
 			mU = stringToByteList(uHelper.ToString());
+			if(mU.size() > ouLength) {
+				mU = substr(mU, 0, ouLength);
+			}
+
 		}
 
 		RefCountPtr<PDFObject> oE(inParser->QueryDictionaryObject(encryptionDictionary.GetPtr(), "OE"));
@@ -178,6 +190,9 @@ EStatusCode DecryptionHelper::Setup(PDFParser* inParser, const string& inPasswor
 		else {
 			ParsedPrimitiveHelper oEHelper(oE.GetPtr());
 			mOE = stringToByteList(oEHelper.ToString());
+			if(mOE.size() > oEuELength) {
+				mOE = substr(mOE, 0, oEuELength);
+			}
 		}	
 
 		RefCountPtr<PDFObject> uE(inParser->QueryDictionaryObject(encryptionDictionary.GetPtr(), "UE"));
@@ -189,6 +204,9 @@ EStatusCode DecryptionHelper::Setup(PDFParser* inParser, const string& inPasswor
 		} else {
 			ParsedPrimitiveHelper uEHelper(uE.GetPtr());
 			mUE = stringToByteList(uEHelper.ToString());
+			if(mUE.size() > oEuELength) {
+				mUE = substr(mUE, 0, oEuELength);
+			}
 		}
 
 		RefCountPtr<PDFObject> perms(inParser->QueryDictionaryObject(encryptionDictionary.GetPtr(), "Perms"));

PDFWriterTesting/CMakeLists.txt

@@ -45,6 +45,7 @@ create_test_sourcelist (Tests
   OutputFileStreamTest.cpp
   PageModifierTest.cpp
   PageOrderModification.cpp
+  ParsePDFWithOwner.cpp
   ParsingBadXref.cpp
   ParsingFaulty.cpp
   PDFCopyingContextTest.cpp

PDFWriterTesting/Materials/password.pdf

@@ -0,0 +1,55 @@
+#include "PDFParser.h"
+#include "EStatusCode.h"
+#include "InputFile.h"
+#include "RefCountPtr.h"
+#include "PDFDictionary.h"
+
+#include <iostream>
+
+#include "testing/TestIO.h"
+
+using namespace PDFHummus;
+
+int ParsePDFWithOwner(int argc, char* argv[])
+{
+    int pIndex = 0;
+	EStatusCode status; 
+    PDFParser parser;
+
+	do
+	{
+        InputFile pdfFile;
+		status = pdfFile.OpenFile(BuildRelativeInputPath(argv, "password.pdf"));
+		if(status != eSuccess)
+		{
+			cout<<"unable to open file for reading. should be in TestMaterials/password.pdf\n";
+			break;
+		}
+
+		status = parser.StartPDFParsing(pdfFile.GetInputStream(), PDFParsingOptions("000000"));
+		if(status != PDFHummus::eSuccess)
+		{
+			cout<<"unable to parse input file";
+			break;
+		}        
+
+        if(!parser.IsEncryptionSupported()) {
+            cout<<"PDFParser does not support encryption, cannot continue\n";
+            status = PDFHummus::eFailure;
+            break;
+        }
+
+        RefCountPtr<PDFDictionary> pageDict(parser.ParsePage(pIndex));
+        if(pageDict.GetPtr() == NULL)
+        {
+            cout<<"unable to parse page "<<pIndex<<"\n";
+            status = PDFHummus::eFailure;
+            break;
+        }
+    }while(false);
+
+
+    return status == eSuccess ? 0:1;
+
+
+}

PDFWriterTesting/ParsePDFWithOwner.cpp

@@ -70,7 +70,21 @@ int RecryptPDF(int argc, char* argv[])
 		{
 			cout << "failed to decrypt PDF2.0\n";
 			break;
-		}			
+		}		
+		
+		// again with the owner password
+		status = PDFWriter::RecryptPDF(
+			BuildRelativeInputPath(argv,"PDFWithPassword20.pdf"),
+			"owner",
+			BuildRelativeOutputPath(argv,"RecryptPDFWithPasswordToNothingOwnerPDF20.pdf"),
+			LogConfiguration::DefaultLogConfiguration(),
+			PDFCreationSettings(true, true),
+			ePDFVersion20);
+		if (status != PDFHummus::eSuccess)
+		{
+			cout << "failed to decrypt PDF2.0 with owner password\n";
+			break;
+		}				
 #endif
 
 		// recrypt an encrypted document with new password