Lua Requires Chilkat v9.5.0.83+

Ed25519 Key Exchange (Shared Secret)

See more Ed25519 Examples

Demonstrates how to create an Ed25519 shared secret for use in key exchange. Lua

local chilkat = require("chilkat")

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

-- Alice's private key, a:
--     77076d0a7318a57d3c16c17251b26645df4c2f87ebc0992ab177fba51db92c2a
-- Alice's public key, X25519(a, 9):
--     8520f0098930a754748b7ddcb43ef75a0dbf3a0d26381af4eba4a98eaa9b4e6a
-- Bob's private key, b:
--     5dab087e624a8a4b79e17f8b83800ee66f3bb1292618b6fd1c2f8b27ff88e0eb
-- Bob's public key, X25519(b, 9):
--     de9edb7d7b7dc1b4d35b61c2ece435373f8343c85b78674dadfc7e146f882b4f
-- Their shared secret, K:
--     4a5d9d5ba4ce2de1728e3bf480350f25e07e21c947d19e3376f09b3c1e161742

local alicePrivKey = "77076d0a7318a57d3c16c17251b26645df4c2f87ebc0992ab177fba51db92c2a"
local bobPubKey = "de9edb7d7b7dc1b4d35b61c2ece435373f8343c85b78674dadfc7e146f882b4f"

local privKey = chilkat.PrivateKey.new()
-- This example shows only one way of loading an Ed25519 private key.
-- Chilkat can load other formats (JWK, PEM, ASN.1 DER, etc.)
-- You may do so by calling LoadAnyFormat or LoadAnyFormatFile.
local success = privKey:load_ed25519(alicePrivKey, "")
if not success then
    print(privKey.last_error_text)
    return
end

local pubKey = chilkat.PublicKey.new()
success = pubKey:load_ed25519(bobPubKey)
if not success then
    print(pubKey.last_error_text)
    return
end

-- Create the shared secret:
local eddsa = chilkat.EdDSA.new()
local sharedSecret = eddsa:shared_secret_enc(privKey, pubKey, "hexlower")
if not eddsa.last_method_success then
    print(eddsa.last_error_text)
    return
end

print("Computed: " .. sharedSecret)
print("Expected: 4a5d9d5ba4ce2de1728e3bf480350f25e07e21c947d19e3376f09b3c1e161742")