Send an Email with a Digital Signature

See more Email Object Examples

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.

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    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 := chilkat.NewEmail()
    email.SetSubject("Signed email")
    email.SetBody("This message will be sent with a digital signature.")
    email.SetFrom("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 := chilkat.NewCert()
    success = cert.LoadPfxFile("qa_data/certs/signer.pfx","pfx_password")
    if success == false {
        fmt.Println(cert.LastErrorText())
        email.DisposeEmail()
        cert.DisposeCert()
        return
    }

    //  Provide the signing certificate.
    success = email.SetSigningCert(cert)
    if success == false {
        fmt.Println(email.LastErrorText())
        email.DisposeEmail()
        cert.DisposeCert()
        return
    }

    //  Request that the email be sent with a digital signature.
    email.SetSendSigned(true)

    fmt.Println("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.

    email.DisposeEmail()
    cert.DisposeCert()