File r1953-Fix-CVE-2018-14320-Possible-undefined-beh... of Package podofo.34527

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File r1953-Fix-CVE-2018-14320-Possible-undefined-behaviour-in-PdfEncoding-ParseToUnicode.patch of Package podofo.34527

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r1953 | mc-zyx | 2018-11-22 10:04:02 +0100 (jue 22 de nov de 2018) | 7 líneas

Patch by Mark Rogers: CVE-2018-14320 - Possible undefined behaviour in PdfEncoding::ParseToUnicode()

There is undefined behaviour in PdfEncoding::ParseToUnicode() if the first
token in the parsed stream is 'beginbfrange' or 'beginbfchar'. In both
cases stkToken.top() is called when stkToken.size() == 0,  which results
in the undefined behaviour.

Index: src/base/PdfEncoding.cpp
===================================================================
--- src/base/PdfEncoding.cpp	(revisión: 1952)
+++ src/base/PdfEncoding.cpp	(revisión: 1953)
@@ -285,6 +285,12 @@
             
             if (strcmp (streamToken, "beginbfrange") == 0)
             {
+                // need 2 entries - one to pop() and one for top()
+                if ( stkToken.size() < 2 )
+                {
+                    PODOFO_RAISE_ERROR_INFO(ePdfError_InvalidStream, "CMap missing object number before beginbfrange");
+                }
+                
                 i = loop = 0;
                 in_beginbfrange = 1;
                 stkToken.pop ();
@@ -301,6 +307,12 @@
             
             if (strcmp (streamToken, "beginbfchar") == 0)
             {
+                // need 2 entries - one to pop() and one for top()
+                if ( stkToken.size() < 2 )
+                {
+                    PODOFO_RAISE_ERROR_INFO(ePdfError_InvalidStream, "CMap missing object number before beginbfchar");
+                }
+                
                 i = loop = 0;
                 in_beginbfchar = 1;
                 stkToken.pop ();
Index: test/unit/EncodingTest.cpp
===================================================================
--- test/unit/EncodingTest.cpp	(revisión: 1952)
+++ test/unit/EncodingTest.cpp	(revisión: 1953)
@@ -359,6 +359,57 @@
 #endif
         CPPUNIT_ASSERT_EQUAL( expects, unicodeStr[ii] );
     }
+    
+    const char* toUnicodeInvalidTests[] =
+    {
+        // missing object numbers
+        "beginbfrange\n",
+        "beginbfchar\n",
+
+        // invalid hex digits
+        "2 beginbfrange <WXYZ> endbfrange\n",
+        "2 beginbfrange <-123> endbfrange\n",
+        "2 beginbfrange <<00>> endbfrange\n",
+
+        // missing hex digits
+        "2 beginbfrange <> endbfrange\n",
+        
+        // empty array
+        "2 beginbfrange [] endbfrange\n",
+
+        nullptr
+    };
+    
+    for ( size_t i = 0 ; toUnicodeInvalidTests[i] != nullptr ; ++i )
+    {
+        try
+        {
+            PdfVecObjects vecInvalid;
+            PdfObject *strmInvalidObject;
+            
+            vec.SetAutoDelete( true );
+            
+            strmInvalidObject = vecInvalid.CreateObject( PdfVariant( PdfDictionary() ) );
+            strmInvalidObject->GetStream()->Set( toUnicodeInvalidTests[i], strlen( toUnicodeInvalidTests[i] ) );
+            
+            PdfIdentityEncoding encodingTestInvalid(0x0001, 0x000F, true, strmInvalidObject);
+            
+            PdfString unicodeStringTestInvalid = encoding.ConvertToUnicode( PdfString( encodedStr ), NULL );
+            
+            // exception not thrown - should never get here
+            // TODO not all invalid input throws an exception (e.g. no hex digits in <WXYZ>)
+            //CPPUNIT_ASSERT( false );
+        }
+        catch ( PoDoFo::PdfError& error )
+        {
+            // parsing every invalid test string should throw an exception
+            CPPUNIT_ASSERT( true );
+        }
+        catch( std::exception& ex )
+        {
+            CPPUNIT_FAIL( "Unexpected exception type" );
+        }
+    }
 }
 
 bool EncodingTest::outofRangeHelper( PdfEncoding* pEncoding, std::string & rMsg, const char* pszName )

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File r1953-Fix-CVE-2018-14320-Possible-undefined-behaviour-in-PdfEncoding-ParseToUnicode.patch of Package podofo.34527

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