How to check whether a rar file is pwd protected?

Aspose.ZIP Product Family
1

Hi, Support:

How to know whether a Rar file is pwd protected.

Thanks for your help.

2

Hello, now the only way is trying to extract and catch an exception.

First case - file names are not encrypted.

using(var a = new RarArchive("data.rar"))
{
   try
   {
        using(var src = a.Entries[0].Open()) 
       //Open method raises ArgumentNullException of encrypted entry.
        {
             byte[] buffer = new byte[8192];
             int bytesRead;
             while ((bytesRead = src.Read(buffer, 0, buffer.Length)) > 0)
                   destination.Write(buffer, 0, bytesRead);                        
         }
      }
   catch (System.ArgumentNullException ex) {
        //ex.ParamName is "password"
        //ex.Message starts with "Password for decryption was not supplied."
   }
}

Alternatively, you can check if archive entry is RarArchiveEntryEncrypted.

using(var a = new RarArchive("data.rar"))
{
    if (a.Entries[0] is RarArchiveEntryEncrypted) {
        ...
    }
}
3

Second case - file names are encrypted.

try
{
    using(var a = new RarArchive("data.rar"))
    //Instantiation raises an InvalidOperationException
    {
       ...
    }
}
catch(System.InvalidOperationException ex)
{
    //ex.Message starts with "File names are encrypted"
}
4

Put it all together.

try
{
    using(var a = new RarArchive("data.rar"))
    {
       Stream src;
       if (a.Entries[0] is RarArchiveEntryEncrypted)
          src = a.Entries[0].Open("T0pSecret"));                 
       else src = a.Entries[0].Open());
              
       using(src)
       {
          ...
       }       
    }
}
catch(System.InvalidOperationException ex)
{
    //Check if file names are encrypted.
}
5

Thanks very much.

And as for zip/7z file, the same way to check password protected files? if not, what is the method?

6

You are correct. Encrypted 7z archive entry can be cast to SevenZipArchiveEntryEncrypted type. Encrypted zip entry can be cast to ArchiveEntryEncrypted type.