PowerShell

Send an Email with a Digital Signature

Demonstrates the Chilkat Email.SendSigned property. Set it to true to have the email sent with a digital signature (the default is false). Signing also requires a certificate with access to its private key. This example loads that certificate (and its private key) from a PFX file with Cert.LoadPfxFile, supplies it via SetSigningCert, and enables signed sending.

Background: Signing is the mirror image of encrypting. To encrypt for a recipient you use their public certificate; to sign you use your own private key, and recipients verify with your public certificate. A signature does not hide the message — a signed email is still readable by anyone — but it proves who sent it and guarantees the content was not tampered with. A PFX (also called PKCS#12, .pfx or .p12) is a password-protected file that bundles a certificate together with its private key, making it a convenient single-file source for signing credentials.

Chilkat PowerShell Downloads

Download Chilkat for PowerShell

PowerShell

Add-Type -Path "C:\chilkat\ChilkatDotNet47-x64\ChilkatDotNet47.dll"

$success = $false

#  Demonstrates the Email.SendSigned property with a full signing setup.  Set SendSigned
#  to true to have the email sent with a digital signature.  Signing requires a certificate
#  with access to its private key, which we load here from a PFX (.pfx / .p12) file.

$email = New-Object Chilkat.Email
$email.Subject = "Signed email"
$email.Body = "This message will be sent with a digital signature."
$email.From = "alice@example.com"
$email.AddTo("Bob","bob@example.com")

#  Load the signing certificate (including its private key) from a PFX file.
#  The 2nd argument is the PFX password.
$cert = New-Object Chilkat.Cert
$success = $cert.LoadPfxFile("qa_data/certs/signer.pfx","pfx_password")
if ($success -eq $false) {
    $($cert.LastErrorText)
    exit
}

#  Provide the signing certificate.
$success = $email.SetSigningCert($cert)
if ($success -eq $false) {
    $($email.LastErrorText)
    exit
}

#  Request that the email be sent with a digital signature.
$email.SendSigned = $true

$("SendSigned = " + $email.SendSigned)

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