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Verify the correct zip code password in vb.net

I want to check if the zip code has a specific password in vb.net. How to create a type function check_if_zip_pass(file, pass) As Boolean?

I can not find anything in the .net infrastructure that does this already, unless I miss something incredibly obvious.

This method should NOT retrieve files, return Trueonly if the skipped pass is valid and Falseif not.

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3 answers

Use a third-party library like DotNetZip . Keep in mind that passwords in zip files apply to records, and not to the entire zip file. Therefore, your test is not entirely clear.

, WinZip zipfile, , . , , - . , . , .

, zip , , . ( zip). . . , Stream.Null.

public bool CheckZipPassword(string filename, string password)
{
    bool success = false;
    try
    {
        using (ZipFile zip1 = ZipFile.Read(filename))
        {
            var bitBucket = System.IO.Stream.Null;
            foreach (var e in zip1)
            {
                if (!e.IsDirectory && e.UsesEncryption)
                {
                    e.ExtractWithPassword(bitBucket, password);
                }
            }
        }
        success = true;    
    }
    catch(Ionic.Zip.BadPasswordException) { }
    return success;
}

! #. VB.NET :

    Public Function CheckZipPassword(filename As String, password As String) As System.Boolean
        Dim success As System.Boolean = False
        Try
            Using zip1 As ZipFile = ZipFile.Read(filename)
                Dim bitBucket As System.IO.Stream = System.IO.Stream.Null
                Dim e As ZipEntry
                For Each e in zip1
                    If (Not e.IsDirectory) And e.UsesEncryption Then
                        e.ExtractWithPassword(bitBucket, password)
                    End If
                Next
             End Using
             success = True
        Catch ex As Ionic.Zip.BadPasswordException
        End Try
        Return success
    End Function
+2

SharpZipLib .NET , ZIP . VB.NET.

Imports ICSharpCode.SharpZipLib.Core
Imports ICSharpCode.SharpZipLib.Zip

Public Sub ExtractZipFile(archiveFilenameIn As String, password As String, outFolder As String)
    Dim zf As ZipFile = Nothing
    Try
        Dim fs As FileStream = File.OpenRead(archiveFilenameIn)
        zf = New ZipFile(fs)
        If Not [String].IsNullOrEmpty(password) Then    ' AES encrypted entries are handled automatically
            zf.Password = password
        End If
        For Each zipEntry As ZipEntry In zf
            If Not zipEntry.IsFile Then     ' Ignore directories
                Continue For
            End If
            Dim entryFileName As [String] = zipEntry.Name
            ' to remove the folder from the entry:- entryFileName = Path.GetFileName(entryFileName);
            ' Optionally match entrynames against a selection list here to skip as desired.
            ' The unpacked length is available in the zipEntry.Size property.

            Dim buffer As Byte() = New Byte(4095) {}    ' 4K is optimum
            Dim zipStream As Stream = zf.GetInputStream(zipEntry)

            ' Manipulate the output filename here as desired.
            Dim fullZipToPath As [String] = Path.Combine(outFolder, entryFileName)
            Dim directoryName As String = Path.GetDirectoryName(fullZipToPath)
            If directoryName.Length > 0 Then
                Directory.CreateDirectory(directoryName)
            End If

            ' Unzip file in buffered chunks. This is just as fast as unpacking to a buffer the full size
            ' of the file, but does not waste memory.
            ' The "Using" will close the stream even if an exception occurs.
            Using streamWriter As FileStream = File.Create(fullZipToPath)
                StreamUtils.Copy(zipStream, streamWriter, buffer)
            End Using
        Next
    Finally
        If zf IsNot Nothing Then
            zf.IsStreamOwner = True     ' Makes close also shut the underlying stream
            ' Ensure we release resources
            zf.Close()
        End If
    End Try
End Sub

, , , , (, ..). , , , "TEST" . , , .

+2

Not much is built into the scope for this. Here you can try using the SharpZipLib library:

public static bool CheckIfCorrectZipPassword(string fileName, string tempDirectory, string password)
{
    byte[] buffer= new byte[2048];
    int n;
    bool isValid = true;

    using (var raw = File.Open(fileName, FileMode.Open, FileAccess.Read))
    {
        using (var input = new ZipInputStream(raw))
        {
            ZipEntry e;
            while ((e = input.GetNextEntry()) != null)
            {
                input.Password = password;
                if (e.IsDirectory) continue;
                string outputPath = Path.Combine(tempDirectory, e.FileName);

                try
                {
                    using (var output = File.Open(outputPath, FileMode.Create, FileAccess.ReadWrite))
                    {
                        while ((n = input.Read(buffer, 0, buffer.Length)) > 0)
                        {
                            output.Write(buffer, 0, n);
                        }
                    }
                }
                catch (ZipException ze)
                {
                    if (ze.Message == "Invalid Password")
                    {
                        isValid = false;
                    }
                }
                finally
                {
                    if (File.Exists(outputPath))
                    {
                        // careful, this can throw exceptions
                        File.Delete(outputPath);
                    }
                }
                if (!isValid)
                {
                    break;
                }
            }
        }
    }
    return isValid;
}

Apologies for C #; should be simple enough to convert to VB.NET.

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