Remove Zip Encryption

Opens an encrypted zip archive and rewrites it with no encrypton.

Download: Chilkat .NET Assemblies

Chilkat.Zip zip = new Chilkat.Zip();

bool success;

//  Any string unlocks the component for the 1st 30-days.
success = zip.UnlockComponent("Anything for 30-day trial");
if (success != true) {
    MessageBox.Show(zip.LastErrorText);
    return;
}

//  An encrypted .zip may be "opened" without providing a
//  password.  However, the contents cannot be unzipped
//  without setting the DecryptPassword property.
success = zip.OpenZip("myEncrypted.zip");
if (success != true) {
    MessageBox.Show(zip.LastErrorText);
    return;
}

//  Set the DecryptPassword property:
zip.DecryptPassword = "myPassword";

//  Indicate that when the zip is to be written again,
//  it should be neither AES encrypted, or password-protected
//  (i.e. older Zip 2.0 encryption)
zip.Encryption = 0;
zip.PasswordProtect = false;

//  Set the filename of the new unencrypted .zip to be written:
zip.FileName = "unencrypted.zip";

//  Write the unencrypted .zip
//  What happens during WriteZipAndClose?  --
//  The encrypted entries from myEncrypted.zip are streamed in,
//  decrypted, and then written out directly into unencrypted.zip
//  In other words, internally the component is smart enough
//  to stream the data from the existing .zip to the new .zip
//  automatically, decrypting in the process..
success = zip.WriteZipAndClose();
if (success != true) {
    MessageBox.Show(zip.LastErrorText);
    return;
}

MessageBox.Show("OK!");