Lua

Encrypt File using X.509 Certificate using AES in CBC Mode

See more Encryption Examples

Demonstrates how to encrypt a file using an X.509 Certificate's public key, where the underlying bulk encryption algorithm is 128-bit AES in CBC mode. (The underlying bulk encryption algorithm can be specified to be other algorithms/strengths.) Lua

local chilkat = require("chilkat")

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

local crypt = chilkat.Crypt2.new()

-- Use public-key cryptography for encryption.
crypt.crypt_algorithm = "pki"

-- Get an X.509 certificate to use for encrypting.
-- Note: Chilkat provides many different ways of loading a certificate, from many different formats,
-- or if on Windows, from the installed certificates on the system.
-- This example simply loads a certificate from a file.
-- Also, for encryption, only the public key is needed.  Digital certificates embed the public key
-- within the X.509 format itself.  Therefore, if you have a certificate, you also have the public key.
local cert = chilkat.Cert.new()
local success = cert:load_from_file("qa_data/certs/testCert.cer")
if not success then
    print(cert.last_error_text)
    return
end

success = crypt:set_encrypt_cert(cert)
if not success then
    print(crypt.last_error_text)
    return
end

-- Indicate the underlying bulk encryption algorithm to be used:
crypt.pkcs7_crypt_alg = "aes"
crypt.key_length = 128

-- Note: When doing public-key encryption the underlying bulk symmetric cipher mode will always be CBC. (at least with Chilkat...)

-- There's one last option that could be set.  If is the RSA encryption encryption/padding scheme.
-- By default, RSAES_PKCS1-V1_5 is used.  If desired, the OaepPadding property could be set to true to
-- use RSAES_OAEP.  (We'll leave it set at the default value of false)
crypt.oaep_padding = false

-- Everything is specified.  Now just encrypt...
-- The output is PKCS7 in binary DER format.
success = crypt:ck_encrypt_file("qa_data/hamlet.xml", "qa_output/hamlet.p7")
if not success then
    print(crypt.last_error_text)
    return
end

print("Finished.")