Bug 329715: investigate why some AV's flag us, and prevent it

patch: use rot13 on keys to avoid being flagged by avira antivirus
r=darin

toolkit/components/url-classifier/src/nsUrlClassifierDBService.cpp

@@ -66,7 +66,8 @@ static const PRLogModuleInfo *gUrlClassifierDbServiceLog = nsnull;
 #define LOG(args)
 #endif
 
-#define DATABASE_FILENAME "urlclassifier.sqlite"
+// Change filename each time we change the db schema.
+#define DATABASE_FILENAME "urlclassifier2.sqlite"
 
 // Singleton instance.
 static nsUrlClassifierDBService* sUrlClassifierDBService;
@@ -76,6 +77,40 @@ static nsIThread* gDbBackgroundThread = nsnull;
 
 static const char* kNEW_TABLE_SUFFIX = "_new";
 
+// This maps A-M to N-Z and N-Z to A-M.  All other characters are left alone.
+// Copied from mailnews/mime/src/mimetext.cpp
+static const unsigned char kRot13Table[256] = {
+  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
+  21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39,
+  40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58,
+  59, 60, 61, 62, 63, 64, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90,
+  65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 91, 92, 93, 94, 95, 96,
+  110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 97, 98,
+  99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 123, 124, 125, 126,
+  127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141,
+  142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156,
+  157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171,
+  172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186,
+  187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201,
+  202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216,
+  217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231,
+  232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246,
+  247, 248, 249, 250, 251, 252, 253, 254, 255 };
+
+// Does an in place rotation of the line
+static void
+Rot13Line(nsCString &line)
+{
+  nsCString::iterator start, end;
+  line.BeginWriting(start);
+  line.EndWriting(end);
+  while (start != end) {
+    *start = kRot13Table[*start];
+    ++start;
+  }
+}
+
+
 // -------------------------------------------------------------------------
 // Actual worker implemenatation
 class nsUrlClassifierDBServiceWorker : public nsIUrlClassifierDBServiceWorker
@@ -172,8 +207,6 @@ nsUrlClassifierDBServiceWorker::Exists(const nsACString& tableName,
                                        const nsACString& key,
                                        nsIUrlClassifierCallback *c)
 {
-  LOG(("Exists\n"));
-
   nsresult rv = OpenDb();
   if (NS_FAILED(rv)) {
     NS_ERROR("Unable to open database");
@@ -196,7 +229,9 @@ nsUrlClassifierDBServiceWorker::Exists(const nsACString& tableName,
   // If CreateStatment failed, this probably means the table doesn't exist.
   // That's ok, we just return an emptry string.
   if (NS_SUCCEEDED(rv)) {
-    rv = selectStatement->BindUTF8StringParameter(0, key);
+    nsCString keyROT13(key);
+    Rot13Line(keyROT13);
+    rv = selectStatement->BindUTF8StringParameter(0, keyROT13);
     NS_ENSURE_SUCCESS(rv, rv);
 
     PRBool hasMore = PR_FALSE;
@@ -248,7 +283,7 @@ nsUrlClassifierDBServiceWorker::CheckTables(const nsACString & tableNames,
       changedTables.Append(tableName);
     }
   }
-  
+
   c->HandleEvent(changedTables);
   return NS_OK;
 }
@@ -535,22 +570,31 @@ nsUrlClassifierDBServiceWorker::ProcessUpdateTable(
     // Insert operation of the form "+KEY\tVALUE"
     const nsCSubstring &key = Substring(aLine, 1, spacePos - 1);
     const nsCSubstring &value = Substring(aLine, spacePos + 1);
-    aUpdateStatement->BindUTF8StringParameter(0, key);
+
+    // We use ROT13 versions of keys to avoid antivirus utilities from
+    // flagging us as a virus.
+    nsCString keyROT13(key);
+    Rot13Line(keyROT13);
+    
+    aUpdateStatement->BindUTF8StringParameter(0, keyROT13);
     aUpdateStatement->BindUTF8StringParameter(1, value);
 
     rv = aUpdateStatement->Execute();
     NS_WARN_IF_FALSE(NS_SUCCEEDED(rv), "Failed to update");
   } else if ('-' == op) {
     // Remove operation of the form "-KEY"
+    nsCString keyROT13;
     if (spacePos == kNotFound) {
       // No trailing tab
       const nsCSubstring &key = Substring(aLine, 1);
-      aDeleteStatement->BindUTF8StringParameter(0, key);
+      keyROT13.Assign(key);
     } else {
       // With trailing tab
       const nsCSubstring &key = Substring(aLine, 1, spacePos - 1);
-      aDeleteStatement->BindUTF8StringParameter(0, key);
+      keyROT13.Assign(key);
     }
+    Rot13Line(keyROT13);
+    aDeleteStatement->BindUTF8StringParameter(0, keyROT13);
 
     rv = aDeleteStatement->Execute();
     NS_WARN_IF_FALSE(NS_SUCCEEDED(rv), "Failed to delete");