Lua

Get the Certificate Used to Decrypt an Email

Demonstrates the Chilkat Email.LastDecryptCert method, which copies the certificate used to decrypt this email into a Cert object. It should be called after a successful decryption. This example loads an encrypted email and, if it was decrypted, reads the decrypting certificate's common name.

Background: When a message could be decrypted with one of several available private keys, it is often useful to know which certificate actually did the job — for auditing, for confirming the message was encrypted for the expected identity, or for logging. LastDecryptCert hands you that certificate as an object so you can inspect its subject, issuer, validity dates, and more.

Chilkat Lua Downloads

Download Chilkat for Lua

Lua

local chilkat = require("chilkat")

-- Demonstrates the LastDecryptCert method, which copies the certificate used to decrypt
-- this email into a Cert object.  Call it after a successful decryption.

local email = chilkat.Email.new()

local success = email:load_eml("qa_data/eml/encrypted.eml")
if not success then
    print(email.last_error_text)
    return
end

if email.received_encrypted then
    if email.decrypted then
        -- Get the certificate that was used to decrypt the email.
        local cert = chilkat.Cert.new()
        success = email:last_decrypt_cert(cert)
        if success then
            print("Decrypted with certificate (CN): " .. cert.subject_cn)
        end
    end
end

-- Note: The path "qa_data/..." is a relative local filesystem path,
-- relative to the current working directory of the running application.