Xojo Plugin Requires Chilkat v11.0.0+
RSASSA-PSS Sign Binary Data

Signs binary data to create a PKCS7/CMS signature. The signature algorithm is RSASSA-PSS with SHA256.
Chilkat Xojo Plugin Downloads

Xojo Plugin
Dim success As Boolean
success = False

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

Dim crypt As New Chilkat.Crypt2

//  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
success = pfx.LoadPfxFile("qa_data/rsassa-pss/privatekey.pfx","PFX_PASSWORD")
If (success = False) Then
    System.DebugLog(pfx.LastErrorText)
    Return
End If

//  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 New Chilkat.Cert
success = pfx.CertAt(0,cert)
If (success = False) Then
    System.DebugLog(pfx.LastErrorText)
    Return
End If

success = crypt.SetSigningCert(cert)

//  Indicate that RSASSA-PSS with SHA256 should be used.
crypt.SigningAlg = "pss"
crypt.HashAlgorithm = "sha256"

crypt.EncodingMode = "base64_mime"

//  Load a binary file to be signed:
Dim binaryData As New Chilkat.BinData
success = binaryData.LoadFile("qa_data/jpg/starfish20.jpg")
If (success <> True) Then
    System.DebugLog("Failed to load file.")
    Return
End If

//  Sign the binary bytes to get a PKCS7 detached signature in base64 format:
Dim pkcs7sig As String
pkcs7sig = crypt.SignBdENC(binaryData)
System.DebugLog("Detached PCKS7 Signature:")
System.DebugLog(pkcs7sig)

//  This signature looks like this:

//  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
//  MQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTcwNDI5MTYxMDI2WjAvBgkqhkiG9w0BCQQx
//  IgQgrjUQkoMeBYUhmDGjPg147WybF0w2LAY6F+Ih6qHUMB8wXwYJKoZIhvcNAQkPMVIwUDALBglg
//  hkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqGSIb3DQMCAgFAMAcGBSsO
//  AwIHMA0GCCqGSIb3DQMCAgEoMIGxBgkrBgEEAYI3EAQxgaMwgaAwgZIxCzAJBgNVBAYTAkFVMREw
//  DwYDVQQIDAhWaWN0b3JpYTESMBAGA1UEBwwJTWVsYm91cm5lMSEwHwYDVQQKDBhJbnRlcm5ldCBX
//  aWRnaXRzIFB0eSBMdGQxDzANBgNVBAMMBldpZGdldDEoMCYGCSqGSIb3DQEJARYZYWRtaW5AaW50
//  ZXJuZXR3aWRnZXRzLmNvbQIJAMPsJCT11cniMIGzBgsqhkiG9w0BCRACCzGBo6CBoDCBkjELMAkG
//  A1UEBhMCQVUxETAPBgNVBAgMCFZpY3RvcmlhMRIwEAYDVQQHDAlNZWxib3VybmUxITAfBgNVBAoM
//  GEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDEPMA0GA1UEAwwGV2lkZ2V0MSgwJgYJKoZIhvcNAQkB
//  FhlhZG1pbkBpbnRlcm5ldHdpZGdldHMuY29tAgkAw+wkJPXVyeIwPQYJKoZIhvcNAQEKMDCgDTAL
//  BglghkgBZQMEAgGhGjAYBgkqhkiG9w0BAQgwCwYJYIZIAWUDBAIBogMCASAEgYCWV0g82volvnwf
//  YpwIpqpQzMmTPBKNQmFGjbyH2opdcbJwgu2qEFvaXkyjYDtgQ7XsCqc15dm6Ee1Ujkosbp57kLTt
//  /WbwxY1CC/uxs3oV+5ESUyB+2iocTYABYn4ye0FhBPut86n/gzZTL+RLG6Z1fxwwzkoxWUp7GjKK
//  58mveQ==

//  The ASN.1 of the signature can be examined by browsing to https://lapo.it/asn1js/ ,
//  then copy-and-paste the Base64 signature into the form and decode..

//  The signature can be verified against the original data like this:
success = crypt.VerifyBdENC(binaryData,pkcs7sig)
System.DebugLog("Signature verified: " + Str(success))

//  Now we'll create an opaque signature (the opposite of a detached signature). 
//  An opaque signature is a PKCS7/CMS message that contains both the original data and
//  the signature.  The verification process extracts the original data.

//  Then OpaqueSignBd method in-place signs the binaryData.
//  The contents of binaryData are replaced with the CMS/PKCS7 message.
success = crypt.OpaqueSignBd(binaryData)

//  Show the contents of the opaque signature in base64 format:
System.DebugLog("Opaque Signature:")
System.DebugLog(binaryData.GetEncoded("base64_mime"))

//  MIIKCgYJKoZIhvcNAQcCoIIJ+zCCCfcCAQExDzANBglghkgBZQMEAgEFADCCAywGCSqGSIb3DQEH
//  AaCCAx0EggMZ/9j/4AAQSkZJRgABAQEASABIAAD//gAmRmlsZSB3cml0dGVuIGJ5IEFkb2JlIFBo
//  b3Rvc2hvcD8gNC4w/9sAQwAQCwwODAoQDg0OEhEQExgoGhgWFhgxIyUdKDozPTw5Mzg3QEhcTkBE
//  V0U3OFBtUVdfYmdoZz5NcXlwZHhcZWdj/9sAQwEREhIYFRgvGhovY0I4QmNjY2NjY2NjY2NjY2Nj
//  Y2NjY2NjY2NjY2NjY2NjY2NjY2NjY2NjY2NjY2NjY2NjY2Nj/8IAEQgAFAAUAwERAAIRAQMRAf/E
//  ABcAAAMBAAAAAAAAAAAAAAAAAAIDBAX/xAAYAQADAQEAAAAAAAAAAAAAAAABAgMEAP/aAAwDAQAC
//  EAMQAAAB2kZYNNEijWKddfTmLgALWH//xAAbEAACAgMBAAAAAAAAAAAAAAABAgMRAAQSE//aAAgB
//  AQABBQL0XqN+pM2aqJGMiqFFCyg7z//EABwRAAICAgMAAAAAAAAAAAAAAAERAAIQIQMSUf/aAAgB
//  AwEBPwHqU5aqAxx+y1tMQl4elj//xAAcEQEAAQUBAQAAAAAAAAAAAAABEQACEBIhA1H/2gAIAQIB
//  AT8B3Bhqy7ZcenyiwmGgDhiOzj//xAAdEAABAwUBAAAAAAAAAAAAAAABAAIREBIhIkFR/9oACAEB
//  AAY/ArZyn+CgxtxWuJaoCnqDuin/xAAcEAABBAMBAAAAAAAAAAAAAAABABEhYRAxQVH/2gAIAQEA
//  AT8hkEwPUUR9DYfE4nxtRpIkBTsayuALIiuY/9oADAMBAAIAAwAAABDWPTsf/8QAGhEAAwADAQAA
//  AAAAAAAAAAAAAAEREDFBIf/aAAgBAwEBPxC0DVPcWm+Ce4OesrkE6bjH/8QAGBEBAQEBAQAAAAAA
//  AAAAAAAAAREAQRD/2gAIAQIBAT8QahMiOc8YgSrnTY3ELclHXn//xAAcEAEBAAIDAQEAAAAAAAAA
//  AAABEQAhMUFxEFH/2gAIAQEAAT8Qn3igmSZSj+c4N4zapMy9IjFV98wncN2iuLFsCEbDGxQkI6RO
//  /n//2aCCAvgwggL0MIICXaADAgECAgkAw+wkJPXVyeIwDQYJKoZIhvcNAQELBQAwgZIxCzAJBgNV
//  BAYTAkFVMREwDwYDVQQIDAhWaWN0b3JpYTESMBAGA1UEBwwJTWVsYm91cm5lMSEwHwYDVQQKDBhJ
//  bnRlcm5ldCBXaWRnaXRzIFB0eSBMdGQxDzANBgNVBAMMBldpZGdldDEoMCYGCSqGSIb3DQEJARYZ
//  YWRtaW5AaW50ZXJuZXR3aWRnZXRzLmNvbTAeFw0xNjExMDExNjUyMzJaFw0yMTEwMzExNjUyMzJa
//  MIGSMQswCQYDVQQGEwJBVTERMA8GA1UECAwIVmljdG9yaWExEjAQBgNVBAcMCU1lbGJvdXJuZTEh
//  MB8GA1UECgwYSW50ZXJuZXQgV2lkZ2l0cyBQdHkgTHRkMQ8wDQYDVQQDDAZXaWRnZXQxKDAmBgkq
//  hkiG9w0BCQEWGWFkbWluQGludGVybmV0d2lkZ2V0cy5jb20wgZ8wDQYJKoZIhvcNAQEBBQADgY0A
//  MIGJAoGBAMYh2gKPJq+z4X9GbRUgHibo7tUvWP7UiqJ6hH00RfYZC+7ZUJ1x7LF/2prDVvGKkS+M
//  vBSTDsx74FOUulZBsEwfzuzoqmwLwxXJeEwuk/Sgzw0WLH+8vPbB0uFSHsJm8kDSmWqQmT1uPntA
//  i74Q7WS1QczYMVvqxyS8IvbLJsPXAgMBAAGjUDBOMB0GA1UdDgQWBBQ40oq7bOxciuKdbEgZPrni
//  +txDCzAfBgNVHSMEGDAWgBQ40oq7bOxciuKdbEgZPrni+txDCzAMBgNVHRMEBTADAQH/MA0GCSqG
//  SIb3DQEBCwUAA4GBACsW92Lm72LZAXVDD5x0LWXvDZjf6rpEiSWfZbytYkWN7TTrjijyFfLu/jqC
//  IkJ52YVQuWGbWftcixkbLZbeUnvu/lqCf2AXBe7WHdyqQZeSi14TpJAlBdaCxbcZY+945u9MvwsX
//  jLnt+Az1lZL5X0wlqN67jhF/+1TXtMtgqO8SMYIDszCCA68CAQEwgaAwgZIxCzAJBgNVBAYTAkFV
//  MREwDwYDVQQIDAhWaWN0b3JpYTESMBAGA1UEBwwJTWVsYm91cm5lMSEwHwYDVQQKDBhJbnRlcm5l
//  dCBXaWRnaXRzIFB0eSBMdGQxDzANBgNVBAMMBldpZGdldDEoMCYGCSqGSIb3DQEJARYZYWRtaW5A
//  aW50ZXJuZXR3aWRnZXRzLmNvbQIJAMPsJCT11cniMA0GCWCGSAFlAwQCAQUAoIICNDAYBgkqhkiG
//  9w0BCQMxCwYJKoZIhvcNAQcBMBwGCSqGSIb3DQEJBTEPFw0xNzA0MjkxNjEwMjZaMC8GCSqGSIb3
//  DQEJBDEiBCCuNRCSgx4FhSGYMaM+DXjtbJsXTDYsBjoX4iHqodQwHzBfBgkqhkiG9w0BCQ8xUjBQ
//  MAsGCWCGSAFlAwQBAjAKBggqhkiG9w0DBzAOBggqhkiG9w0DAgICAIAwDQYIKoZIhvcNAwICAUAw
//  BwYFKw4DAgcwDQYIKoZIhvcNAwICASgwgbEGCSsGAQQBgjcQBDGBozCBoDCBkjELMAkGA1UEBhMC
//  QVUxETAPBgNVBAgMCFZpY3RvcmlhMRIwEAYDVQQHDAlNZWxib3VybmUxITAfBgNVBAoMGEludGVy
//  bmV0IFdpZGdpdHMgUHR5IEx0ZDEPMA0GA1UEAwwGV2lkZ2V0MSgwJgYJKoZIhvcNAQkBFhlhZG1p
//  bkBpbnRlcm5ldHdpZGdldHMuY29tAgkAw+wkJPXVyeIwgbMGCyqGSIb3DQEJEAILMYGjoIGgMIGS
//  MQswCQYDVQQGEwJBVTERMA8GA1UECAwIVmljdG9yaWExEjAQBgNVBAcMCU1lbGJvdXJuZTEhMB8G
//  A1UECgwYSW50ZXJuZXQgV2lkZ2l0cyBQdHkgTHRkMQ8wDQYDVQQDDAZXaWRnZXQxKDAmBgkqhkiG
//  9w0BCQEWGWFkbWluQGludGVybmV0d2lkZ2V0cy5jb20CCQDD7CQk9dXJ4jA9BgkqhkiG9w0BAQow
//  MKANMAsGCWCGSAFlAwQCAaEaMBgGCSqGSIb3DQEBCDALBglghkgBZQMEAgGiAwIBIASBgAGVtpI5
//  slxfw+1EyJK4jqxokLvUrqksBLotv1vaP4QaSeF2A1lNrsPfJoEjZJpD1F6vXrFPsR4sPD+6n7P/
//  lz3sGoFykTjE2rPwKEFIbzfxD3gSZKJPWFgDa19DojarmwJMkSPXt9TQEzdjDPrbsCGLYOy29Puq
//  ZDI1rUcyxg7Y

//  The ASN.1 of the signature can be examined by browsing to https://lapo.it/asn1js/ ,
//  then copy-and-paste the Base64 signature into the form and decode..

//  The signature is verified, and the original data restored like this:
success = crypt.OpaqueVerifyBd(binaryData)
If (success <> True) Then
    System.DebugLog("Signature verification failed.")
    System.DebugLog(crypt.LastErrorText)
    Return
End If

//  Save the extracted data to a file:
success = binaryData.WriteFile("qa_output/extractedStarfish20.jpg")

System.DebugLog("Signature verified.")