(VB.NET) Encrypt MIME using RSAES-OAEP with SHA256 and AES-128 content encryption

Demonstrates how to encrypt MIME 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 requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim success As Boolean
Dim mime As New Chilkat.Mime

' Create a MIME message to encrypt.
mime.NewMultipartMixed()
mime.AddHeaderField("someHeader1","Some value 1")
mime.AddHeaderField("someHeader2","Some value 2")

Dim part0 As New Chilkat.Mime
part0.AddHeaderField("hdrA","Some value A")
part0.AddHeaderField("hdrB","Some value B")
part0.ContentType = "text/plain"
part0.SetBody("This is the plain-text body.")

Dim part1 As New Chilkat.Mime
part1.AddHeaderField("hdrX","Some value X")
part1.AddHeaderField("hdrY","Some value Y")
part1.ContentType = "text/xml"
part1.SetBody("<a>This is the XML body</a>")

mime.AppendPart(part0)
mime.AppendPart(part1)

' The MIME to be encrypted:
Dim sbMime As New Chilkat.StringBuilder
mime.GetMimeSb(sbMime)
Debug.WriteLine(sbMime.GetAsString())

' 	Content-Type: multipart/mixed; boundary="------------080303020600020604010008"
' 	someHeader1: Some value 1
' 	someHeader2: Some value 2
' 
' 	--------------080303020600020604010008
' 	hdrA: Some value A
' 	hdrB: Some value B
' 	Content-Type: text/plain
' 
' 	This is the plain-text body.
' 	--------------080303020600020604010008
' 	hdrX: Some value X
' 	hdrY: Some value Y
' 	Content-Type: text/xml
' 
' 	<a>This is the XML body</a>
' 	--------------080303020600020604010008--
' 


' Load an RSA-based certificate.
' (Encrypting MIME only requires the public key.  Decrypting MIME requires the private key.)
Dim cert As New Chilkat.Cert
success = cert.LoadFromFile("qa_data/rsaes-oaep/cert.pem")
If (success <> True) Then
    Debug.WriteLine(cert.LastErrorText)
    Exit Sub
End If


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

' Encrypt the MIME (to create S/MIME, which stands for "Secure MIME")
success = mime.Encrypt(cert)
If (success <> True) Then
    Debug.WriteLine(mime.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("---------------")
Debug.WriteLine("Encrypted MIME:")
Debug.WriteLine("---------------")
Debug.WriteLine(mime.GetMime())

Debug.WriteLine("Success.")


' ---------------------------------------------------
' This is sample output for RSAES-OAEP encrypted MIME:
' ---------------------------------------------------

' Content-Type: application/x-pkcs7-mime; name="smime.p7m"; smime-type="enveloped-data"
' someHeader1: Some value 1
' someHeader2: Some value 2
' Content-Disposition: attachment; filename="smime.p7m"
' Content-Transfer-Encoding: base64
' 
' MIIDvAYJKoZIhvcNAQcDoIIDrTCCA6kCAQAxggGgMIIBnAIBADB1MGgxCzAJBgNVBAYTAlVTMQsw
' CQYDVQQIDAJJTDEQMA4GA1UEBwwHV2hlYXRvbjEhMB8GA1UECgwYSW50ZXJuZXQgV2lkZ2l0cyBQ
' dHkgTHRkMRcwFQYDVQQDDA5DaGlsa2F0V2lkZ2V0cwIJAMRwugDmvniwMBwGCSqGSIb3DQEBBzAP
' oA0wCwYJYIZIAWUDBAIBBIIBAFaUL1ga1bOrdqYKcMm+FHUacBvzfBxk0fnPA0AMBdN8BvTWT3CN
' YuqBhjOGyq0FpYD9pVZybUuFMCVsVyIW2O62HnsOK58YaPEUUcdH2sI+yjqX9UAn0P0nVDSsVdeK
' W8x9kMfZg+3UP+y1q+lu7VRJO3f2C9oLQpTkc4VW4n7UOcUI0waykLCjCTL8lFDb7/J3GeuMKyhH
' 5riNz50kpbzqn7m2Ks9yA+QmcTdXclclGFr2vwEUFzSdT2pxh/vaUrogCxkYWbQ2eV7vZg6O4kV0
' aqHBqySkPTAzHKiHH8K8GVdlTuJ8350CpICa4T8w7/Ht5I7dyOPPKy4C+rVtrvcwggH+BgkqhkiG
' 9w0BBwEwHQYJYIZIAWUDBAECBBDTC2WNBN+z2I47/4Feu9YqgIIB0MZvl3nC/q/Wzil6HtfQTr12
' Q5moHY+ORzAa1P9XvX2ZUFhW530mV395mQw/A4o4ekmX9eRPEZquYzZPLT8hNeZIuNdhpcSQUmad
' rKnKkR0wKJ3jJ3LhOIohVBQSYs8kVDZKq6lJBIznlsurFelZoNEhyRschhteDZx5rb7fCe8c2+/O
' DHxaqaHCAzm/Bd7kcg6FFfuTZy3tu0PgP5IsXN4OFA3kkvwjAs4XsVS8jdIcmDNBkYieE8WmJOIm
' Mz7mh/CHWLgWfGKa0Dkb9RcbFgLwYNT3GzuXFw9XPbKkEZjEAtJajWbN6P0WQl96YYd9qZxUpGxZ
' zjTHEYzViUdUXolfpLufttrRXyxN1RFWhNFMFbv66xYqklMSgpdM/Mbk+EuvX6eXayDPvDBpfYMw
' NoRAzv1Ony2c0ez9rBemJICicxAzpuvHbRxdjYs63Dnv+TYgpBK12AxWWpPIjXvw0WQKgTC3Tg8s
' EnuGhpENqso/clJBEBSn4+2WhYtYbdI5sVme67lvqQl1Xxy3r18SWaQbyDOwgYi1E+54lMDOxMy0
' y0FPHk5pP45DnXWj+XORPp5LhuZr5mf62YOXSSUwR5P0cXy4Rc+pN5lhRQPCf5z2