Lua Requires Chilkat v11.0.0+

Convert RSA Private Key to Public Key

See more RSA Examples

Demonstrates how to get a public RSA key from a private RSA key. Lua

local chilkat = require("chilkat")

local privKey = chilkat.PrivateKey.new()

-- Step 1: Load the private key from a source.
-- (Chilkat can load private keys from all types of formats, and from in-memory bytes or encoded strings.
-- see the online reference documentation for more options.)
local success = privKey:load_pem_file("qa_data/pem/VP_Private.pem")
if not success then
    print(privKey.last_error_text)
    return
end

-- Step 2: Get the public key object from the private key object.
local pubKey = chilkat.PublicKey.new()
privKey:to_public_key(pubKey)

-- Step 3: Save the public key in a desired format.
-- (Chilkat can load or save public and private keys in many different formats.  See
-- the online reference documentation for more options.)

-- Saves to a PKCS8 PEM file.
local bPreferPkcs1 = false
success = pubKey:save_pem_file(bPreferPkcs1, "qa_data/pem/VP_Public.pem")
if not pubKey.last_method_success then
    print(pubKey.last_error_text)
    return
end

print("Extracted and saved public key from private key.")