Lua

RSA Sign using a Private Key on a USB Token or Smartcard

See more Apple Keychain Examples

Create an RSA signature using a private key stored on a USB token or smartcard. Lua

local chilkat = require("chilkat")

-- Assuming the smartcard/USB token is installed with the correct drivers from the manufacturer,
-- this code can work on multiple platforms including Windows, MacOS, Linux, and iOS.

-- Chilkat automatically detects and determines the way in which the HSM is used,
-- which can be by PKCS11, Apple Keychain, Microsoft CNG / Crypto API, or ScMinidriver.

local cert = chilkat.Cert.new()

-- Set the token/smartcard PIN prior to loading.
cert.smart_card_pin = "123456"

-- Specify the certificate by its common name.
local success = cert:load_from_smartcard("cn=chilkat-rsa-2048")
if not success then
    print(cert.last_error_text)
    return
end

print("Signing with cert: " .. cert.subject_cn)

-- Create data to be hashed and signed.
local bd = chilkat.BinData.new()
for i = 0, 100 do
    bd:append_encoded("000102030405060708090A0B0C0D0E0F", "hex")
end

local rsa = chilkat.Rsa.new()

-- Use the certificate's private key for signing.
success = rsa:set_x509_cert(cert, true)
if not success then
    print(rsa.last_error_text)
    return
end

-- Sign the SHA-256 hash of the contents of bd.
local bdSig = chilkat.BinData.new()
success = rsa:sign_bd(bd, "sha256", bdSig)
if not success then
    print(rsa.last_error_text)
    return
end

-- The RSA signature is equal in length to the size of the RSA key.
print("Output signature size in bits = " .. (bdSig.num_bytes * 8))

-- We can save the signature for later verification..
bdSig:write_file("rsaSignatures/test1.sig")

-- See the example to verify the RSA signature:
-- Verfies an RSA Signature