(VB.NET) 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.

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' 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.)
Dim pfx As New Chilkat.Pfx
Dim success As Boolean = pfx.LoadPfxFile("qa_data/rsassa-pss/privatekey.pfx","PFX_PASSWORD")
If (success <> True) Then
    Debug.WriteLine(pfx.LastErrorText)
    Exit Sub
End If


Dim email As New Chilkat.Email

' Create a simple email.
email.Subject = "Sample RSASSA-PSS Signed Email"
email.Body = "Sample RSASSA-PSS Signed Email"
email.From = "from_name@mydomain.com"
' Add one ore more recipients..
email.AddTo("Chilkat Support","support@chilkatsoft.com")
email.AddTo("Chilkat GMail","chilkat.support@gmail.com")

' Indicate that the email is to be signed, and that we want to use RSASSA-PSS.
email.SendSigned = True
email.SigningAlg = "pss"
email.SigningHashAlg = "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.)
Dim cert As Chilkat.Cert = pfx.GetCert(0)
If (pfx.LastMethodSuccess <> True) Then
    Debug.WriteLine(pfx.LastErrorText)
    Exit Sub
End If


' Tell the email object to use this cert (and private key) for signing.
email.SetSigningCert(cert)


Dim mailman As New Chilkat.MailMan

' Set the SMTP settings for your email account on your mail server.
mailman.SmtpUsername = "SMTP_LOGIN"
mailman.SmtpPassword = "SMTP_PASSWORD"
mailman.SmtpHost = "MY_SMTP_DOMAIN_OR_IP"
mailman.SmtpPort = 587
mailman.StartTLS = 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..
mailman.OpaqueSigning = False

' Send the email.  The mailman will sign the email as directed by the 
' property settings of the email object.
success = mailman.SendEmail(email)
If (success <> True) Then
    Debug.WriteLine(mailman.LastErrorText)
    Exit Sub
End If


success = mailman.CloseSmtpConnection()
If (success <> True) Then
    Debug.WriteLine("Connection to SMTP server not closed cleanly.")
End If


Debug.WriteLine("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--