Lua

Open a Zip Archive

See more Zip Examples

Demonstrates how to open a zip, or an encrypted .zip, or a legacy password-protected .zip. Lua

local chilkat = require("chilkat")

local zip = chilkat.Zip.new()

-- Open a non-encrypted .zip
local success = zip:open_zip("qa_data/zips/sample.zip")
if not success then
    print(zip.last_error_text)
    return
end

print("Num entries = " .. zip.num_entries)

-- ...
-- ...

zip:close_zip()

-- ----------------------------------------------------------------------------
-- Open an encrypted zip...

-- The two main types of encryption used in ZIP archives are Password-Protected and AES.
--

-- ---------------------------------------
-- 1. Legacy Password-Protected Zip
--
-- This is the older and less secure method of encrypting ZIP archives.
-- It provides a basic level of security, but is considered weak by modern standards.
-- It is vulnerable to various attacks, including known-plaintext attacks and brute force attacks.
-- Although Chilkat allows it, you shouldn't create new zip archives using legacy password-protection.

-- ---------------------------------------
-- 2. AES Encrypted Zip
--
-- AES encryption is a more modern and secure method for encrypting ZIP archives.
-- It provides strong encryption based on the AES algorithm, which is widely regarded as secure.
-- AES supports different key lengths, typically 128-bit, 192-bit, and 256-bit.

-- When opening an encrypted zip, your application only needs to provide the correct password.
-- The information about the type of encryption and the key length (if AES) is already embedded within the encrypted .zip.

-- Provide the decrypt password because we are opening an existing .zip (decrypting)
zip.decrypt_password = "thePassword"

success = zip:open_zip("qa_data/zips/encryptedSamples/ziptest_256.zip")
if not success then
    print(zip.last_error_text)
    return
end

print("Num entries = " .. zip.num_entries)

-- ...
-- ...

zip:close_zip()