(Delphi DLL) Send a Signed Email using RSASSA-PSS with SHA256

Demonstrates how to sign and send an email using the RSASSA-PSS signing algorithm with the SHA256 hash algorithm.

Note: This example requires Chilkat v9.5.0.67 or greater.

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Pfx, MailMan, Cert, Email;

...

procedure TForm1.Button1Click(Sender: TObject);
var
pfx: HCkPfx;
success: Boolean;
email: HCkEmail;
cert: HCkCert;
mailman: HCkMailMan;

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

// Get a digital certificate with private key from a .pfx
// (Chilkat has many different ways to provide a cert + private key for siging.
// Using a PFX is just one possible option.)
pfx := CkPfx_Create();
success := CkPfx_LoadPfxFile(pfx,'qa_data/rsassa-pss/privatekey.pfx','PFX_PASSWORD');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkPfx__lastErrorText(pfx));
    Exit;
  end;

email := CkEmail_Create();

// Create a simple email.
CkEmail_putSubject(email,'Sample RSASSA-PSS Signed Email');
CkEmail_putBody(email,'Sample RSASSA-PSS Signed Email');
CkEmail_putFrom(email,'from_name@mydomain.com');
// Add one ore more recipients..
CkEmail_AddTo(email,'Chilkat Support','support@chilkatsoft.com');
CkEmail_AddTo(email,'Chilkat GMail','chilkat.support@gmail.com');

// Indicate that the email is to be signed, and that we want to use RSASSA-PSS.
CkEmail_putSendSigned(email,True);
CkEmail_putSigningAlg(email,'pss');
CkEmail_putSigningHashAlg(email,'sha256');

// Get the certificate to be used for signing.
// (The typical case for a PFX is that it contains a cert with an associated private key,
// as well as other certificates in the chain of authentication.  The cert with the private
// key should be in the first position at index 0.)
cert := CkPfx_GetCert(pfx,0);
if (CkPfx_getLastMethodSuccess(pfx) <> True) then
  begin
    Memo1.Lines.Add(CkPfx__lastErrorText(pfx));
    Exit;
  end;

// Tell the email object to use this cert (and private key) for signing.
CkEmail_SetSigningCert(email,cert);
CkCert_Dispose(cert);

mailman := CkMailMan_Create();

// Set the SMTP settings for your email account on your mail server.
CkMailMan_putSmtpUsername(mailman,'SMTP_LOGIN');
CkMailMan_putSmtpPassword(mailman,'SMTP_PASSWORD');
CkMailMan_putSmtpHost(mailman,'MY_SMTP_DOMAIN_OR_IP');
CkMailMan_putSmtpPort(mailman,587);
CkMailMan_putStartTLS(mailman,True);

// Signed email can be sent in two different ways.  
// In a multipart/signed email, the signature is attached as a separate MIME part.
// In an opaque email (signedData) the content of the email is encapsulated within the signature
// and the email is sent as "application/pkcs7-mime". 
// Either should be fine, but some receiving systems might require one or the other..
CkMailMan_putOpaqueSigning(mailman,False);

// Send the email.  The mailman will sign the email as directed by the 
// property settings of the email object.
success := CkMailMan_SendEmail(mailman,email);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

success := CkMailMan_CloseSmtpConnection(mailman);
if (success <> True) then
  begin
    Memo1.Lines.Add('Connection to SMTP server not closed cleanly.');
  end;

Memo1.Lines.Add('Mail Sent!');

// -----------------------------------------------------------
// This is the MIME of the RSASSA-PSS signed email that was sent

// 	MIME-Version: 1.0
// 	Date: Thu, 20 Apr 2017 10:14:58 -0500
// 	Message-ID: <3682A87344CB3A4FB5EB5BC9908C0C4DA01DA461@CHILKAT13>
// 	Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha256;
// 	 boundary="------------050103020705000601010800"
// 	X-Priority: 3 (Normal)
// 	Subject: Sample RSASSA-PSS Signed Email
// 	From: support@chilkatsoft.com
// 	To: "Chilkat Support" <support@chilkatsoft.com>,
// 	 "Chilkat GMail" <chilkat.support@gmail.com>
// 
// 	--------------050103020705000601010800
// 	Content-Type: text/plain; format=flowed
// 	Content-Transfer-Encoding: 7bit
// 
// 	Sample RSASSA-PSS Signed Email
// 	--------------050103020705000601010800
// 	Content-Transfer-Encoding: base64
// 	Content-Type: application/pkcs7-signature; name="smime.p7s"
// 	Content-Disposition: attachment; filename="smime.p7s"
// 
// 	MIIG5wYJKoZIhvcNAQcCoIIG2DCCBtQCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg
// 	ggL4MIIC9DCCAl2gAwIBAgIJAMPsJCT11cniMA0GCSqGSIb3DQEBCwUAMIGSMQswCQYDVQQGEwJB
// 	VTERMA8GA1UECAwIVmljdG9yaWExEjAQBgNVBAcMCU1lbGJvdXJuZTEhMB8GA1UECgwYSW50ZXJu
// 	ZXQgV2lkZ2l0cyBQdHkgTHRkMQ8wDQYDVQQDDAZXaWRnZXQxKDAmBgkqhkiG9w0BCQEWGWFkbWlu
// 	QGludGVybmV0d2lkZ2V0cy5jb20wHhcNMTYxMTAxMTY1MjMyWhcNMjExMDMxMTY1MjMyWjCBkjEL
// 	MAkGA1UEBhMCQVUxETAPBgNVBAgMCFZpY3RvcmlhMRIwEAYDVQQHDAlNZWxib3VybmUxITAfBgNV
// 	BAoMGEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDEPMA0GA1UEAwwGV2lkZ2V0MSgwJgYJKoZIhvcN
// 	AQkBFhlhZG1pbkBpbnRlcm5ldHdpZGdldHMuY29tMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKB
// 	gQDGIdoCjyavs+F/Rm0VIB4m6O7VL1j+1IqieoR9NEX2GQvu2VCdceyxf9qaw1bxipEvjLwUkw7M
// 	e+BTlLpWQbBMH87s6KpsC8MVyXhMLpP0oM8NFix/vLz2wdLhUh7CZvJA0plqkJk9bj57QIu+EO1k
// 	tUHM2DFb6sckvCL2yybD1wIDAQABo1AwTjAdBgNVHQ4EFgQUONKKu2zsXIrinWxIGT654vrcQwsw
// 	HwYDVR0jBBgwFoAUONKKu2zsXIrinWxIGT654vrcQwswDAYDVR0TBAUwAwEB/zANBgkqhkiG9w0B
// 	AQsFAAOBgQArFvdi5u9i2QF1Qw+cdC1l7w2Y3+q6RIkln2W8rWJFje00644o8hXy7v46giJCedmF
// 	ULlhm1n7XIsZGy2W3lJ77v5agn9gFwXu1h3cqkGXkoteE6SQJQXWgsW3GWPveObvTL8LF4y57fgM
// 	9ZWS+V9MJajeu44Rf/tU17TLYKjvEjGCA7MwggOvAgEBMIGgMIGSMQswCQYDVQQGEwJBVTERMA8G
// 	A1UECAwIVmljdG9yaWExEjAQBgNVBAcMCU1lbGJvdXJuZTEhMB8GA1UECgwYSW50ZXJuZXQgV2lk
// 	Z2l0cyBQdHkgTHRkMQ8wDQYDVQQDDAZXaWRnZXQxKDAmBgkqhkiG9w0BCQEWGWFkbWluQGludGVy
// 	bmV0d2lkZ2V0cy5jb20CCQDD7CQk9dXJ4jANBglghkgBZQMEAgEFAKCCAjQwGAYJKoZIhvcNAQkD
// 	MQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTcwNDIwMTUxNDU4WjAvBgkqhkiG9w0BCQQx
// 	IgQgoHOtpFiAgti0cwDw46C8wyYSZbhx2yJqJZ/qRE8WPSQwXwYJKoZIhvcNAQkPMVIwUDALBglg
// 	hkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqGSIb3DQMCAgFAMAcGBSsO
// 	AwIHMA0GCCqGSIb3DQMCAgEoMIGxBgkrBgEEAYI3EAQxgaMwgaAwgZIxCzAJBgNVBAYTAkFVMREw
// 	DwYDVQQIDAhWaWN0b3JpYTESMBAGA1UEBwwJTWVsYm91cm5lMSEwHwYDVQQKDBhJbnRlcm5ldCBX
// 	aWRnaXRzIFB0eSBMdGQxDzANBgNVBAMMBldpZGdldDEoMCYGCSqGSIb3DQEJARYZYWRtaW5AaW50
// 	ZXJuZXR3aWRnZXRzLmNvbQIJAMPsJCT11cniMIGzBgsqhkiG9w0BCRACCzGBo6CBoDCBkjELMAkG
// 	A1UEBhMCQVUxETAPBgNVBAgMCFZpY3RvcmlhMRIwEAYDVQQHDAlNZWxib3VybmUxITAfBgNVBAoM
// 	GEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDEPMA0GA1UEAwwGV2lkZ2V0MSgwJgYJKoZIhvcNAQkB
// 	FhlhZG1pbkBpbnRlcm5ldHdpZGdldHMuY29tAgkAw+wkJPXVyeIwPQYJKoZIhvcNAQEKMDCgDTAL
// 	BglghkgBZQMEAgGhGjAYBgkqhkiG9w0BAQgwCwYJYIZIAWUDBAIBogMCASAEgYCDQpT6vJZ9zERJ
// 	JVX69PGUfCN5Eq9pKzoOTQSrIBe1YgNDSPd5pyOPP2MN1RpI0T/GTQZw4iWy5LZq0T5sjmk3fFVB
// 	+VZjKtkTuhGaCdzMQXomVLBbI2fN4UaA4v1/Ayrqr8SY9Rsa20TpKv/bufK7oYs083UOtlcA1EHY
// 	41wQ5A==
// 
// 	--------------050103020705000601010800--

CkPfx_Dispose(pfx);
CkEmail_Dispose(email);
CkMailMan_Dispose(mailman);

end;