NotImplemented exception thrown on AES unzip.

[BertusVanZyl]

Steps to reproduce

using (FileStream fs = File.OpenRead(fileName))
{
    var zf = new ZipFile(fs);
    zf.Password = "aaa";
    foreach (ZipEntry zipEntry in zf)
    {
        if (!zipEntry.IsFile)
        {
            continue; // Ignore directories
        }
        
        byte[] buffer = new byte[zipEntry.Size];
        try
        {
            using (Stream zipStream = zf.GetInputStream(zipEntry))
            {
                zipStream.Read(buffer, 0, buffer.Length);
            }
        }
        catch (Exception ex)
        {
            //NotImplemented thrown on dispose from using block.
        }
    }
}

Expected behavior

The bytes are read from the stream successfully, so the functionality IS implemented. The exception should not be thrown.

Actual behavior

NotImplemented exception is thrown.

Version of SharpZipLib

0.86.0 nuget package.

Obtained from (place an x between the brackets for all that apply)

• Package installed using:
• NuGet

[BertusVanZyl]

Here is an example zip. the password is "aaa'.

aaa.zip

[wsloth]

I have this same problem with the following code:

var zipFile = new ZipFile(zipStream)
{
    Password = "Some Encryption Password"
};

foreach (ZipEntry entry in zipFile)
{
    if (!entry.IsFile) continue;

    string content;
    var zipInputStream = zipFile.GetInputStream(entry);

    // Read file contents
    using (var s = new StreamReader(zipInputStream, Encoding.UTF8))
    {
        content = s.ReadToEnd(); // The file content is properly read without problems
    } // exception is thrown here
}

It seems to me the exception occurs here:

SharpZipLib/src/ICSharpCode.SharpZipLib/Encryption/ZipAESTransform.cs

Line 157 in be53259

throw new NotImplementedException("ZipAESTransform.TransformFinalBlock");

[stealthrabbi]

So what should someone do, given this bug? I can get the input stream and read from it. But we can't close it. Should we call it and catch the exception, or just leave it open? If we're unzipping a large file, I'm concerned about leaving all those stream open. Or, is it sufficient to close the contraining stream (e.g. MemoryStream) that is passed to ZipFile ?

[piksel]

I don't know. This is planned to be fixed for v1.1, and is currently listed as not working as per #35.

I have not been able to work on it for a while though.

[BertusVanZyl]

I cannot reproduce this problem in 1.2.0. I don't know in which version it was fixed.

[piksel]

It was fixed in v1.1, thanks for updating (closing) the issue!