Sample code for 30+ languages & platforms
C#

Determine if a Zip is Encrypted or Password-Protected

See more Zip Examples

Determines whether or not a zip archive is AES encrypted or password-protected.

Chilkat C# Downloads

C#
bool success = false;

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

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

//  An encrypted or password-protected zip can be opened
//  without specifying the password.  However, the contents
//  of the files cannot be unzipped without providing the correct
//  password.

success = zip.OpenZip("something.zip");
if (success != true) {
    Debug.WriteLine(zip.LastErrorText);
    return;
}

//  If the zip is password-protected, meaning that it uses
//  the old (insecure) Zip 2.0 encryption, then the
//  PasswordProtect property will be true
bool bPwdProt = zip.PasswordProtect;
if (bPwdProt) {
    Debug.WriteLine("This zip is password-protected.");
}

//  If the zip is AES encrypted (WinZip compatible) then
//  the Encryption property will be equal to 4.
int encValue = zip.Encryption;
if (encValue == 4) {
    Debug.WriteLine("This zip is AES encrypted.");
}

//  If the Encryption property = 0, then the zip is NOT
//  strong encrypted, and is either password-protected or
//  entirely unencrypted, depending on the value of the
//  PasswordProtect property.

zip.CloseZip();