Lua

Export an Encrypted PKCS #8 Private Key as PEM

Demonstrates the Chilkat PrivateKey.GetPkcs8EncryptedPem method, which exports the key as password-protected PKCS #8 PEM (-----BEGIN ENCRYPTED PRIVATE KEY-----). The only argument is the password; the cipher is selected by the Pkcs8EncryptAlg property.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: This is the safe way to export a key for storage or transfer — the private material is encrypted under a passphrase, so a leaked file is not immediately usable. It is the format to reach for whenever a key leaves your process. Control the encryption cipher with Pkcs8EncryptAlg, and source the password securely rather than hard-coding it.

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Lua

local chilkat = require("chilkat")

-- Load a private key to export.
local privKey = chilkat.PrivateKey.new()
local success = privKey:load_pem_file("qa_data/private.pem")
if not success then
    print(privKey.last_error_text)
    return
end

-- The key password is not hard-coded in a real application; obtain it from an interactive
-- prompt, environment variable, or a secrets vault.
local password = "myKeyPassword"

-- Export as password-protected PKCS #8 PEM ("-----BEGIN ENCRYPTED PRIVATE KEY-----").  The
-- encryption cipher is selected by the Pkcs8EncryptAlg property.
local pem = privKey:get_pkcs8_encrypted_pem(password)
if not privKey.last_method_success then
    print(privKey.last_error_text)
    return
end

print(pem)