(Excel) Send Encrypted Email using RSAES-OAEP with AES-128 CBC and SHA256

Demonstrates how to send encrypted email using RSAES-OAEP with SHA256 and AES-128 content encryption.

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.

' Load an RSA-based certificate.
' (Encrypting an email only requires the public key.  Decrypting an email requires the private key.)
Dim cert As Chilkat.Cert
Set cert = Chilkat.NewCert

success = cert.LoadFromFile("qa_data/rsaes-oaep/cert.pem")
If (success <> True) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

Dim email As Chilkat.Email
Set email = Chilkat.NewEmail

' Create a simple email.
email.Subject = "Sample RSAES-OAEP Encrypted Email"
email.Body = "Sample RSAES-OAEP Encrypted Email"
email.From = "support@chilkatsoft.com"

' Add a recipient.
' (The email is encrypted using the recipient's certificate.
' If sending to multiple recipients, then the AddEncryptCert method would
' need to be called once for each recipient's certificate.)
Dim success As Boolean
success = email.AddTo("Chilkat GMail","chilkat.support@gmail.com")

' Set the email object properties to indicate the desired encryption.
email.Pkcs7CryptAlg = "aes"
' If AES-256 is desired, set the following property to 256.
email.Pkcs7KeyLength = 128
email.OaepPadding = True
' Other choices for the OAEP hash algorithm are "sha1", "sha384", and "sha512"
email.OaepHash = "sha256"

' Provide the certificate to be used for encryption
success = email.AddEncryptCert(cert)

' Don't forget to indicate that the email should be encrypted when sent..
email.SendEncrypted = True

' The mailman object will do the RSAES-OAEP encryption when sending.
Dim mailman As Chilkat.MailMan
Set mailman = Chilkat.NewMailMan

' 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

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

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

Debug.Print "Mail Sent!"

' -----------------------------------------------------------
' This is an example of an RSAES-OAEP encrypted email
' -----------------------------------------------------------

' MIME-Version: 1.0
' Date: Thu, 27 Apr 2017 08:43:32 -0500
' Message-ID: <772DC039F0259C474BAC60240EA2BA2272402308@CHILKAT13>
' Content-Type: application/pkcs7-mime; name="smime.p7m"; smime-type="enveloped-data"
' Content-Transfer-Encoding: base64
' X-Priority: 3 (Normal)
' Subject: Sample RSAES-OAEP Encrypted Email
' From: support@chilkatsoft.com
' To: "Chilkat GMail" <chilkat.support@gmail.com>
' Content-Disposition: attachment; filename="smime.p7m"
' 
' MIICWQYJKoZIhvcNAQcDoIICSjCCAkYCAQAxggGgMIIBnAIBADB1MGgxCzAJBgNVBAYTAlVTMQsw
' CQYDVQQIDAJJTDEQMA4GA1UEBwwHV2hlYXRvbjEhMB8GA1UECgwYSW50ZXJuZXQgV2lkZ2l0cyBQ
' dHkgTHRkMRcwFQYDVQQDDA5DaGlsa2F0V2lkZ2V0cwIJAMRwugDmvniwMBwGCSqGSIb3DQEBBzAP
' oA0wCwYJYIZIAWUDBAIBBIIBABr0E1dKJjK0FAYRz/NCtJmBeB0nUxgcuBnhGPI/UeyGub3cCo+K
' G5F4/iVTBJqVvYIF5+fvBnyTginwv7OiUiFWLyihiFC3NIyZJO22+XMHpNatCffTPZk10WswkTgk
' G3ApnRvGQAaldnFD0Hs8drPU4vBvY9QsjT7YDGa6u2NMX+sr1ewEZArqU0mNfJ6RsEYd5FQbFEVF
' qLmnz8Dt+yhoJlUtfUd8TXIeqHRJ7RxKOTSzlBZaAdTv2QX4oL9IcAgZeTg5iw+yRPkSAwWyg+I/
' 7fybLsUpRGDHTGUU+AvHvP0kYKa1mkvccBVEC/+4hEyhpS1tWIR5ByY6vM76Z+8wgZwGCSqGSIb3
' DQEHATAdBglghkgBZQMEAQIEEKqD0YDHX1NsVDaV32UczpeAcLteQyRPTV4hATjwcPiVelPfeWNs
' xZKRGaEBqLM8+Y+V4ciCFoOlgJuOcP4m1PTHyilfzd+SCsKz5l1C7+sfPf36n2aacX6IWga59Bz5
' QbWrOHDUT7O5PnGwKVgQFw3Cj4GrdPGWKcoqxB0HuKnj3WA=