B4X

PKCS11 XML Signature using Certificate and Private Key on Smart Card / USB Token

See more PKCS11 Examples

Sample code showing how to use PKCS11 to create an XML digital signature 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

'  This example is tested on Windows using a Giesecke and Devrient Sm@rtCafe Expert 3.2 smart card.
'  You will use the DLL (or shared lib) provided by your smart card vendor, or a DLL compatible with your smart card.
'  On Windows, if the DLL is located in C:\Windows\System32, specify only the filename.
'  Otherwise provide the full path.
pkcs11.SharedLibPath = "aetpkss1.dll"

'  Make it an authenticated session by calling Login.
Dim userType As Int = 1
'  Make sure to use the correct PIN for your smart card..
Dim pin As String = "0000"

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.
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 XML signing code is the same as for a cert obtained from any other source..

'  First generate the following XML to be signed:
'  Use this online tool to generate code from sample XML: 
'  Generate Code to Create XML

'  <?xml version="1.0" encoding="UTF-8" standalone="no" ?>
'  <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
'      <SOAP-ENV:Header>
'          <wsse:Security xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" SOAP-ENV:mustUnderstand="1"></wsse:Security>
'      </SOAP-ENV:Header>
'      <SOAP-ENV:Body xmlns:SOAP-SEC="http://schemas.xmlsoap.org/soap/security/2000-12" SOAP-SEC:id="Body">
'          <z:FooBar xmlns:z="http://example.com" />
'      </SOAP-ENV:Body>
'  </SOAP-ENV:Envelope>

Dim xml As ChilkatXml
xml.Initialize
xml.Tag = "SOAP-ENV:Envelope"
xml.AddAttribute("xmlns:SOAP-ENV", "http://schemas.xmlsoap.org/soap/envelope/")
xml.UpdateAttrAt("SOAP-ENV:Header|wsse:Security", True, "xmlns:wsse", "http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd")
xml.UpdateAttrAt("SOAP-ENV:Header|wsse:Security", True, "SOAP-ENV:mustUnderstand", "1")
xml.UpdateAttrAt("SOAP-ENV:Body", True, "xmlns:SOAP-SEC", "http://schemas.xmlsoap.org/soap/security/2000-12")
xml.UpdateAttrAt("SOAP-ENV:Body", True, "SOAP-SEC:id", "Body")
xml.UpdateAttrAt("SOAP-ENV:Body|z:FooBar", True, "xmlns:z", "http://example.com")

Dim gen As ChilkatXmlDSigGen
gen.Initialize("gen")

'  Indicate where the Signature will be inserted.
gen.SigLocation = "SOAP-ENV:Envelope|SOAP-ENV:Header|wsse:Security"

'  Add a reference to the fragment of the XML to be signed.

'  Note: "Body" refers to the XML element having an "id" equal to "Body", where "id" is case insensitive
'  and where any namespace might qualify the attribute.  In this case, the SOAP-ENV:Body fragment is signed
'  NOT because the tag = "Body", but because it has SOAP-SEC:id="Body"
gen.AddSameDocRef("Body", "sha1", "EXCL_C14N", "", "")

'  (You can read about the SignedInfoPrefixList in the online reference documentation.  It's optional..)
gen.SignedInfoPrefixList = "wsse SOAP-ENV"

'  Provide the private key for signing via the certificate, and indicate that
'  we want the base64 of the certificate embedded in the KeyInfo.
gen.KeyInfoType = "X509Data"
gen.X509Type = "Certificate"

Dim bUsePrivateKey As Boolean = True
success = gen.SetX509Cert(cert, bUsePrivateKey)
If success <> True Then
    Log(gen.LastErrorText)
    success = pkcs11.CloseSession
    Return
End If


'  Everything's specified.  Now create and insert the Signature
Dim sbXml As ChilkatStringBuilder
sbXml.Initialize
xml.EmitCompact = True
xml.GetXmlSb(sbXml)

success = gen.CreateXmlDSigSb(sbXml)
If success <> True Then
    Log(gen.LastErrorText)
    success = pkcs11.CloseSession
    Return
End If


'  Examine the XML with the digital signature inserted
Log(sbXml.GetAsString)

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

'  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.")