Lua

Export a Private Key as DER into a BinData

Demonstrates the Chilkat PrivateKey.GetPkcsBd method, which exports the key as DER into a BinData. The first argument selects PKCS #1 (true) versus PKCS #8 (false), the second is the password (empty for unencrypted), and the third is the BinData that receives the bytes.

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 in-memory binary export — the raw DER bytes land in a BinData ready to hash, encrypt, or hand to another API without a temporary file. One method covers several cases: the boolean picks the traditional (PKCS #1) versus modern (PKCS #8) structure, and a nonempty password produces an encrypted PKCS #8 export (with the cipher from Pkcs8EncryptAlg). Source any password securely.

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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 the key as DER into a BinData.  The 1st argument selects PKCS #1 (true) versus PKCS #8
-- (false); the 2nd is the password (empty string for an unencrypted export); the 3rd is the
-- BinData that receives the DER bytes.
local usePkcs1 = false
local bd = chilkat.BinData.new()
success = privKey:get_pkcs_bd(usePkcs1, password, bd)
if not success then
    print(privKey.last_error_text)
    return
end

print("Exported " .. bd.num_bytes .. " DER bytes.")