Lua Requires Chilkat v9.5.0.83+

Get an EC Key in Raw Hex Format

See more ECC Examples

Demonstrates how to get the private and public key parts of an EC (ECDSA) key in lowercase hex formmat. Lua

local chilkat = require("chilkat")

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

-- Load an EC key from some format..
local privKey = chilkat.PrivateKey.new()

-- This loads an ECDSA key from an unencrypted PEM file (no password required).
local success = privKey:load_any_format_file("qa_data/ecc/openssl_ecc_privKey.pem", "")
if not success then
    print(privKey.last_error_text)
    return
end

-- The key type should be "ecc" to indicate an EC key.
print("key type = " .. privKey.key_type)

-- What is the size of the private key in bits?
print("size in bits = " .. privKey.bit_length)

-- Get the private and public EC key parts in raw hex format:
local sbPubKeyHex = chilkat.StringBuilder.new()
local privKeyHex = privKey:get_raw_hex(sbPubKeyHex)

-- If the private key size in bits is 256, then we should have a 32-byte key (a 64 character hex string).
print("private key = " .. privKeyHex)

-- The public key is composed of the "x" and "y" parts, and is composed like this:  04||HEX(x)||HEX(y)
print("public key = " .. sbPubKeyHex:get_as_string())

-- Sample output:
-- key type = ecc
-- size in bits = 256
-- private key = ced36f2ba3332be439f79143d69937fc52494cd38e45243c3ea05db183919f1b
-- public key = 045b4edcd501831740895f5907feabb71587076a6314d9d5141f9f8c33a478b8ce08b8dfd2a091eb6355803d7e729876c790bc0b176f2015f3bb103813753f676a