C#

Encrypt Already Existing Zip

See more Zip Examples

To encrypt an already existing non-encrypted .zip, the application must open the .zip, set the encryption related properties, and then re-write. C#

bool success = false;

//  This requires the Chilkat Zip API to have been previously unlocked.
//  See Unlock Chilkat Zip for sample code.

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

//  Open an unencrypted .zip
success = zip.OpenZip("qa_data/zips/test.zip");
if (success != true) {
    Debug.WriteLine(zip.LastErrorText);
    return;
}

//  Unzip to a temp directory.
int numFilesUnzipped = zip.Unzip("qa_output/tmp");
if (numFilesUnzipped < 0) {
    Debug.WriteLine(zip.LastErrorText);
    return;
}

//  Clear the zip object.
zip.NewZip("qa_output/aesTest.zip");

//  Indicate that 128-bit AES encryption is to be used when writing the .zip
zip.Encryption = 4;
zip.EncryptKeyLength = 128;

//  Set the password.
zip.EncryptPassword = "secret";

//  Append the files.
zip.AppendFromDir = "qa_output/tmp";
success = zip.AppendFiles("*.*",true);
if (success != true) {
    Debug.WriteLine(zip.LastErrorText);
    return;
}

//  Write the .zip and close it.
success = zip.WriteZipAndClose();
if (success != true) {
    Debug.WriteLine(zip.LastErrorText);
    return;
}

Debug.WriteLine("Success.");