Xojo Plugin

Sign PDF in the Cloud using AWS CloudHSM

See more Signing in the Cloud Examples

Demonstrates how to sign a PDF using AWS CloudHSM. The signing of the hash happens on a hardware token in AWS CloudHSM. Everything else involving the updating the PDF to add the signature happens locally within Chilkat.

Note: This example requires Chilkat v9.5.0.96 or greater.

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.

// Note: Chilkat's PKCS11 implementation runs on Windows, Linux, Mac OS X, and other supported operating systems.

Dim pkcs11 As New Chilkat.Pkcs11

// Provide the path to the AWS CloudHSM PKCS11 driver.
// This example runs on Windows, so we'll provide the CloudHSM DLL.
// If your code runs on Linux, the CloudHSM driver might be at /opt/cloudhsm/lib/libcloudhsm_pkcs11.so
pkcs11.SharedLibPath = "C:\Program Files\Amazon\CloudHSM\lib\cloudhsm_pkcs11.dll"

// Your PIN should be a string containing your crypto user's login and password, with a colon char delimiting.
// See https://docs.aws.amazon.com/cloudhsm/latest/userguide/pkcs11-pin.html
Dim pin As String
pin = "user:password"
Dim userType As Int32
userType = 1

// Establish a PKCS logged-on session using the driver (.so, .dylib, or .dll) as specified in the SharedLibPath above.
success = pkcs11.QuickSession(userType,pin)
If (success = False) Then
    System.DebugLog(pkcs11.LastErrorText)
    Return
End If

Dim cert As New Chilkat.Cert
success = cert.LoadFromFile("qa_data/certs/myCert.cer")
If (success = False) Then
    System.DebugLog(cert.LastErrorText)
    Return
End If

// Tell the certificate to link with the PKCS11 session.
// The cert's private key should be installed on the CloudHSM.
// If there are multiple private keys on the CloudHSM, then Chilkat will automatically
// locate and use the private key corresponding to the certificate.
success = cert.LinkPkcs11(pkcs11)
If (success = False) Then
    System.DebugLog(cert.LastErrorText)
    Return
End If

// --------------------------------------------------------------------------
// At this point, we have the cert to be used for signing.
// Our PDF signing code is the same as for a cert obtained from any other source..

Dim pdf As New Chilkat.Pdf

// Load a PDF to be signed.
success = pdf.LoadFile("qa_data/pdf/hello.pdf")
If (success = False) Then
    System.DebugLog(pdf.LastErrorText)
    success = pkcs11.CloseSession()
    Return
End If

Dim json As New Chilkat.JsonObject

success = json.UpdateInt("page",1)
success = json.UpdateString("appearance.y","top")
success = json.UpdateString("appearance.x","left")
success = json.UpdateString("appearance.fontScale","10.0")
success = json.UpdateString("signingAlgorithm","pss")
success = json.UpdateString("hashAlgorithm","sha256")

Dim i As Int32
i = 0
json.I = i
success = json.UpdateString("appearance.text[i]","Digitaly signed by: Xyz Widgets, Inc.")
i = i + 1
json.I = i
success = json.UpdateString("appearance.text[i]","current_dt")
i = i + 1
json.I = i
success = json.UpdateString("appearance.text[i]","blah blah blah")

// The certificate is internally linked to the Pkcs11 object, which is currently in an authenticated session.
success = pdf.SetSigningCert(cert)

success = pdf.SignPdf(json,"qa_output/out.pdf")
If (success = False) Then
    System.DebugLog(pdf.LastErrorText)
    success = pkcs11.CloseSession()
    Return
End If

// --------------------------------------------------------------------------

// Revert to an unauthenticated session by calling Logout.
success = pkcs11.Logout()
If (success = False) Then
    System.DebugLog(pkcs11.LastErrorText)
    success = pkcs11.CloseSession()
    Return
End If

// When finished, close the session.
// It is important to close the session (memory leaks will occur if the session is not properly closed).
success = pkcs11.CloseSession()
If (success = False) Then
    System.DebugLog(pkcs11.LastErrorText)
    Return
End If

System.DebugLog("Success.")