B4X

PKCS11 Sign PDF using Certificate and Private Key on Smart Card / USB Token

See more PKCS11 Examples

Sample code showing how to use PKCS11 to sign a PDF with a certificate and private key stored on a smart card or USB token.

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

B4X

Dim success As Boolean = 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 ChilkatPkcs11
pkcs11.Initialize

pkcs11.SharedLibPath = "C:/Program Files (x86)/Gemalto/IDGo 800 PKCS#11/IDPrimePKCS1164.dll"
Dim pin As String = "0000"
Dim userType As Int = 1

'  Establish a PKCS11 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
    Log(pkcs11.LastErrorText)
    Return
End If


'  Get the certificate (on the smart card) that has a private key.
'  There are other ways to locate a certificate on the HSM.
'  This example assumes there is a single certificate w/ private key.
Dim cert As ChilkatCert
cert.Initialize("cert")
success = pkcs11.FindCert("privateKey", "", cert)
If success = True Then
    Log("Cert with private key: " & cert.SubjectCN)
Else
    Log("No certificates having a private key were found.")
    success = pkcs11.CloseSession
    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 ChilkatPdf
pdf.Initialize("pdf")

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


Dim json As ChilkatJsonObject
json.Initialize

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

Dim i As Int = 0
json.I = i
json.UpdateString("appearance.text[i]", "Digitaly signed by: Xyz Widgets, Inc.")
i = i + 1
json.I = i
json.UpdateString("appearance.text[i]", "current_dt")
i = i + 1
json.I = i
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
    Log(pdf.LastErrorText)
    success = pkcs11.CloseSession
    Return
End If


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

'  Revert to an unauthenticated session by calling Logout.
success = pkcs11.Logout
If success = False Then
    Log(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
    Log(pkcs11.LastErrorText)
    Return
End If


Log("Success.")