B4X
Create PKCS7 Attached/Opaque Signature (S/MIME)

Create an S/MIME message with a PKCS7 attached/opaque signature.
Chilkat B4X Downloads

B4X
Dim success As Boolean = False

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

Dim mime As ChilkatMime
mime.Initialize

'  Load a certificate w/ private key for signing.
'  There are many ways of getting a certificate object:
'  from a pfx file, from .cer and private-key files, from the
'  Windows registry-based certificate stores, etc.
'  Load a PFX file into a certificate object.
Dim cert As ChilkatCert
cert.Initialize("cert")
Dim pfxFilepath As String = "pfxFiles/something.pfx"
Dim pfxPassword As String = "secret"
success = cert.LoadPfxFile(pfxFilepath, pfxPassword)
If success = False Then
    Log(cert.LastErrorText)
    Return
End If


'  Create a very simple MIME message to be signed:
success = mime.AddHeaderField("Subject", "This is a test")
success = mime.AddHeaderField("MyCustomHeader", "abc123")
mime.ContentType = "text/plain"
mime.SetBody("This is a plain-text body.")

'  Examine the MIME prior to signing:
Log("--- MIME prior to signing ---")
Log(mime.GetMime)

'  The MIME prior to signing looks like this:
'  -------------------------------------------------------------------------------

'  Subject: This is a test
'  MyCustomHeader: abc123
'  Content-Type: text/plain
'  
'  This is a plain-text body.

'  -------------------------------------------------------------------------------

'  The default hash algorithm used in the signing process is "SHA1".
'  To change it, set the SigningHashAlg property:
mime.SigningHashAlg = "SHA256"

'  Convert the MIME to PKCS7 signed-data.
success = mime.ConvertToSigned(cert)
If success = False Then
    Log(mime.LastErrorText)
    Return
End If


'  Examine the signed MIME
Log("--- MIME converted to PKCS7 signed-data ---")
Log(mime.GetMime)

'  The MIME after signing looks like this:
'  -------------------------------------------------------------------------------

'  Subject: This is a test
'  MyCustomHeader: abc123
'  Content-Disposition: attachment; filename="smime.p7m";
'  Content-Transfer-Encoding: base64
'  Content-Type: application/x-pkcs7-mime;
'   name="smime.p7m"; smime-type="signed-data";
'  
'  MIIObAYJKoZIhvcNAQcCoIIOXTCCDlkCAQExDzANBglghkgBZQMEAgEFADB2BgkqhkiG9w0BBwGg
'  aQRnU3ViamVjdDogVGhpcyBpcyBhIHRlc3QNCk15Q3VzdG9tSGVhZGVyOiBhYmMxMjMNCkNvbnRl
'  bnQtVHlwZTogdGV4dC9wbGFpbg0KDQpUaGlzIGlzIGEgcGxhaW4tdGV4dCBib2R5LqCCCaAwggRm
'  MIIDTqADAgECAhBEvgyLUAAktBHTNi3gs18bMA0GCSqGSIb3DQEBBQUAMIGVMQswCQYDVQQGEwJV
'  UzELMAkGA1UECBMCVVQxFzAVBgNVBAcTDlNhbHQgTGFrZSBDaXR5MR4wHAYDVQQKExVUaGUgVVNF
'  UlRSVVNUIE5ldHdvcmsxITAfBgNVBAsTGGh0dHA6Ly93d3cudXNlcnRydXN0LmNvbTEdMBsGA1UE
'  AxMUVVROLVVTRVJGaXJzdC1PYmplY3QwHhcNOTkwNzA5MTgzMTIwWhcNMTkwNzA5MTg0MDM2WjCB
'  lTELMAkGA1UEBhMCVVMxCzAJBgNVBAgTAlVUMRcwFQYDVQQHEw5TYWx0IExha2UgQ2l0eTEeMBwG
'  A1UEChMVVGhlIFVTRVJUUlVTVCBOZXR3b3JrMSEwHwYDVQQLExhodHRwOi8vd3d3LnVzZXJ0cnVz
'  dC5jb20xHTAbBgNVBAMTFFVUTi1VU0VSRmlyc3QtT2JqZWN0MIIBIjANBgkqhkiG9w0BAQEFAAOC
'  AQ8AMIIBCgKCAQEAzqqBP6OjYXiqMQBVlRGeJw8fHN86m4JoMMBKYR3xLw76vnn3pSPvVVGWhM3b
'  47luPjHYCiBnx/TZv5TrRwQ+As4qol2HBAn2MJ0Yipeyqhz8QdKhNsv7PZG659lwNfrk55DDm6Ob
'  0zz1Epl3sbcJ4GjmHLjzlGOIamr+C3bJvvQi5Ge5qxped8GFB90NbL/uBsd3akGepw/X++6UF7f8
'  hb6kq8QcMd3XttHk8O/fFo+yUpPXodSJoQcuv+EBEkIeGuHYlTTbZHko/7ouEcLl6FuSSPtHC8Js
'  2q0yg0HzpeVBcP1lkG36+lHE+b2WKxkELNNtp9zwf2+DZeJqq4eGdQIDAQABo4GvMIGsMAsGA1Ud
'  DwQEAwIBxjAPBgNVHRMBAf8EBTADAQH/MB0GA1UdDgQWBBTa7WR0FJwUPKvdmam9WyhNizzJ2DBC
'  BgNVHR8EOzA5MDegNaAzhjFodHRwOi8vY3JsLnVzZXJ0cnVzdC5jb20vVVROLVVTRVJGaXJzdC1P
'  YmplY3QuY3JsMCkGA1UdJQQiMCAGCCsGAQUFBwMDBggrBgEFBQcDCAYKKwYBBAGCNwoDBDANBgkq
'  hkiG9w0BAQUFAAOCAQEACB9SsTdEeNv9zrnalZaYqlVkgLVaQN0hpcXB818sTMhHWmnq6PA1NfTQ
'  JfPIpqSHSr0bsXMIvdTDyrY1u1mGdzHNp4AUrhPv/LFI+WslJS1RtixtRcGYyIpWXT7uQ04+ayeO
'  0DpLhQtf0+1qp3XL0VqHLzl1E1pysAKBn77wD4RUIGJsadThTcYNmUMBDRKWjHidv1CisUSqas8X
'  es9vD9T4JFVf8DQWSWY+UEbJY3E4MWK4YrnzU61stSuiEqoZTwnaXueTxo4UCP7wMIAYoIaFTch9
'  14sD/m7V950WrJIsoCPlnJFSH5TfF5Rzw7PBwXEFIAB4vRNSHag+zQAfyDCCBTIwggQaoAMCAQIC
'  EQDm/GiUo2tiCnVnsAEgJ0r7MA0GCSqGSIb3DQEBBQUAMIGVMQswCQYDVQQGEwJVUzELMAkGA1UE
'  CBMCVVQxFzAVBgNVBAcTDlNhbHQgTGFrZSBDaXR5MR4wHAYDVQQKExVUaGUgVVNFUlRSVVNUIE5l
'  dHdvcmsxITAfBgNVBAsTGGh0dHA6Ly93d3cudXNlcnRydXN0LmNvbTEdMBsGA1UEAxMUVVROLVVT
'  RVJGaXJzdC1PYmplY3QwHhcNMDkxMDEyMDAwMDAwWhcNMTAxMDEyMjM1OTU5WjCBoDELMAkGA1UE
'  BhMCVVMxDjAMBgNVBBEMBTYwMTg3MREwDwYDVQQIDAhJbGxpbm9pczEQMA4GA1UEBwwHV2hlYXRv
'  bjEaMBgGA1UECQwRMTcxOSBFIEZvcmVzdCBBdmUxHzAdBgNVBAoMFkNoaWxrYXQgU29mdHdhcmUs
'  IEluYy4xHzAdBgNVBAMMFkNoaWxrYXQgU29mdHdhcmUsIEluYy4wggEiMA0GCSqGSIb3DQEBAQUA
'  A4IBDwAwggEKAoIBAQC5ueUJPjI74J5Yavc3JUCWHEMMd2C9T+4VDuUcN7vzYuIOjsyV1yhzAl8+
'  uxzE+dhfcRK8qw9JbRV56Dzfyz5DqJH9x0rlbzkM24NeNZyM1kXIs2NHCJTYlYUqlVLZ2SXpiqru
'  nnYEFScZho3knWoBYC4841sdUay70pqluo2Y1CBbx5t+zYPXit370hEGzKLNK6XRTevcVQQMvL/f
'  d/gz241M8KBT8yvqTAjv6NJz9tHNUqhYO5mTT65nsIwKQ5/T8L+hsOHi4VM2QdVW6ZD9jrfPIfES
'  yOyfXCx2l9oEHfB3gwgdYQ4Mq9hRG77mIc9H+pw1V0yMmQmEVs0LP6hvAgMBAAGjggFuMIIBajAf
'  BgNVHSMEGDAWgBTa7WR0FJwUPKvdmam9WyhNizzJ2DAdBgNVHQ4EFgQUBMe/RfjpWAOjAMHml1qw
'  DvPa4OowDgYDVR0PAQH/BAQDAgeAMAwGA1UdEwEB/wQCMAAwEwYDVR0lBAwwCgYIKwYBBQUHAwMw
'  EQYJYIZIAYb4QgEBBAQDAgQQMEYGA1UdIAQ/MD0wOwYMKwYBBAGyMQECAQMCMCswKQYIKwYBBQUH
'  AgEWHWh0dHBzOi8vc2VjdXJlLmNvbW9kby5uZXQvQ1BTMEIGA1UdHwQ7MDkwN6A1oDOGMWh0dHA6
'  Ly9jcmwudXNlcnRydXN0LmNvbS9VVE4tVVNFUkZpcnN0LU9iamVjdC5jcmwwNAYIKwYBBQUHAQEE
'  KDAmMCQGCCsGAQUFBzABhhhodHRwOi8vb2NzcC5jb21vZG9jYS5jb20wIAYDVR0RBBkwF4EVYWRt
'  aW5AY2hpbGthdHNvZnQuY29tMA0GCSqGSIb3DQEBBQUAA4IBAQAP/2IpG75SHSFFqjHqvCXy0n0O
'  MTQk2IexnIUBlF7wm0oZquXBG2GlOPd9IXNr7k3wf4G+nZ6rgit6slVT1VxZS8RzqhGT3ZRTa2ud
'  dSqJyKxxrqdBJMY/WWaWVtCSU74AKAAm/ONwD1Zz39IZ2Mr8ApXn2LnZy4ZgI3hZnVR8I92/sppl
'  +NKWr0iMBpcz2KEwXZ5lrS5/4qRFlY+LQgRBFnjoM9WDW1lGEqeHFQQ/dqyrNiRAp+l7OzPBS4aM
'  nfxS+Yj/blpnuW41dVi9TJTXozRwiHzQ41FfrkJMD4JZULc539SK1EU1cYMl13x3JODHlng2IrjZ
'  pCKrFCsSCP2BMYIEJTCCBCECAQEwgaswgZUxCzAJBgNVBAYTAlVTMQswCQYDVQQIEwJVVDEXMBUG
'  A1UEBxMOU2FsdCBMYWtlIENpdHkxHjAcBgNVBAoTFVRoZSBVU0VSVFJVU1QgTmV0d29yazEhMB8G
'  A1UECxMYaHR0cDovL3d3dy51c2VydHJ1c3QuY29tMR0wGwYDVQQDExRVVE4tVVNFUkZpcnN0LU9i
'  amVjdAIRAOb8aJSja2IKdWewASAnSvswDQYJYIZIAWUDBAIBBQCgggJKMBgGCSqGSIb3DQEJAzEL
'  BgkqhkiG9w0BBwEwHAYJKoZIhvcNAQkFMQ8XDTEwMDYzMDE0NTg0MFowLwYJKoZIhvcNAQkEMSIE
'  ILEFXqrFbp/l0XOJyyjW1IJhjJxJaOhLUlZTc8VcabVMMF8GCSqGSIb3DQEJDzFSMFAwCwYJYIZI
'  AWUDBAECMAoGCCqGSIb3DQMHMA4GCCqGSIb3DQMCAgIAgDANBggqhkiG9w0DAgIBQDAHBgUrDgMC
'  BzANBggqhkiG9w0DAgIBKDCBvAYJKwYBBAGCNxAEMYGuMIGrMIGVMQswCQYDVQQGEwJVUzELMAkG
'  A1UECBMCVVQxFzAVBgNVBAcTDlNhbHQgTGFrZSBDaXR5MR4wHAYDVQQKExVUaGUgVVNFUlRSVVNU
'  IE5ldHdvcmsxITAfBgNVBAsTGGh0dHA6Ly93d3cudXNlcnRydXN0LmNvbTEdMBsGA1UEAxMUVVRO
'  LVVTRVJGaXJzdC1PYmplY3QCEQDm/GiUo2tiCnVnsAEgJ0r7MIG+BgsqhkiG9w0BCRACCzGBrqCB
'  qzCBlTELMAkGA1UEBhMCVVMxCzAJBgNVBAgTAlVUMRcwFQYDVQQHEw5TYWx0IExha2UgQ2l0eTEe
'  MBwGA1UEChMVVGhlIFVTRVJUUlVTVCBOZXR3b3JrMSEwHwYDVQQLExhodHRwOi8vd3d3LnVzZXJ0
'  cnVzdC5jb20xHTAbBgNVBAMTFFVUTi1VU0VSRmlyc3QtT2JqZWN0AhEA5vxolKNrYgp1Z7ABICdK
'  +zANBgkqhkiG9w0BAQEFAASCAQBfYh75saVFNXRPOzXOemaoVIFz+OHSsQB1fqXbV+hjGkxuvWAT
'  ldq32luVFFCz2gErWDT8eZ0yFVVwi16XyP7ptZeGU4cIGtrOozq78dziWwbNB021c3Dcw0vmH83m
'  FrU8ZNXYhL2+Lu4PlgvSCxHtC9EKrsP0s3WvBk3nMgXhu4Nmvkl1pCAofhAXWs545TfFB3jLEgeR
'  spbT6PhRR2lErXKF/Ga5NUyUqpw/Ba2YB3fFsbwiMyncmYicnUT2eYxxYBPtX9X6DQSKh3+iLNz0
'  sx89fluXIoqWONjR/XyN8zYd6WtEqMMwY6HQPAblFEuMPHZIhC0h/hfGAVisKLmh
'  

'  -------------------------------------------------------------------------------