Lua

Set the Decryption Certificate for an Email

Demonstrates the Chilkat Email.SetDecryptCert method, which explicitly provides a certificate (with access to its private key) for decrypting a received encrypted email. Set the certificate before loading the encrypted message so Chilkat can decrypt it automatically. This example loads the certificate from a PFX, sets it, and then loads an encrypted email.

Background: Decrypting S/MIME email requires the recipient's private key. On Windows and macOS, Chilkat can find an installed certificate automatically, but when the key lives in a standalone PFX file you provide it explicitly with SetDecryptCert. A PFX (PKCS#12) bundles the certificate and its private key in one password-protected file. If the certificate and key are in separate files, use SetDecryptCert2 instead.

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Lua

local chilkat = require("chilkat")

-- Demonstrates the SetDecryptCert method, which explicitly provides a certificate (with
-- access to its private key) for decrypting a received encrypted email.  Set the cert
-- before loading the encrypted email so it can be decrypted automatically.

local email = chilkat.Email.new()

-- Load a certificate together with its private key from a PFX file.
local cert = chilkat.Cert.new()
local success = cert:load_pfx_file("qa_data/certs/decryption.pfx", "pfx_password")
if not success then
    print(cert.last_error_text)
    return
end

-- Provide the certificate to use for decryption.
success = email:set_decrypt_cert(cert)
if not success then
    print(email.last_error_text)
    return
end

-- Load the encrypted email; Chilkat decrypts it using the certificate.
success = email:load_eml("qa_data/eml/encrypted.eml")
if not success then
    print(email.last_error_text)
    return
end

print("ReceivedEncrypted = " .. tostring(email.received_encrypted))
print("Decrypted = " .. tostring(email.decrypted))

-- Note: Paths such as "qa_data/..." are relative local filesystem paths,
-- relative to the current working directory of the running application.