Xbase++
Create XML Digital Signature using Certificate on Smart Card

Demonstrates how to load a certificate located on a smart card or USB token and then use it for creating an XML digital signature such that the cryptographic signing happens on the smart card.
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LOCAL nSuccess
LOCAL oScmd
LOCAL cReaderName
LOCAL nRetval
LOCAL cCertPart
LOCAL cPartValue
LOCAL oCert
LOCAL oXml
LOCAL oGen
LOCAL nBUsePrivateKey
LOCAL oSbXml

nSuccess := 0

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

oScmd := CreateObject("Chilkat.ScMinidriver")

//  Reader names (smart card readers or USB tokens) can be discovered
//  via List Readers or Find Smart Cards
cReaderName := "SCM Microsystems Inc. SCR33x USB Smart Card Reader 0"
nSuccess := oScmd:AcquireContext(cReaderName)
IF (nSuccess == 0)
    ? oScmd:LastErrorText
    oScmd:destroy()
    RETURN
ENDIF

//  If successful, the name of the currently inserted smart card is available:
? "Card name: " + oScmd:CardName

//  If desired, perform regular PIN authentication with the smartcard.
//  For more details about smart card PIN authentication, see the Smart Card PIN Authentication Example
nRetval := oScmd:PinAuthenticate("user", "000000")
IF (nRetval != 0)
    ? "PIN Authentication failed."
ENDIF

//  You can find a cerficate using any of the following certificate parts:
//  "subjectDN" -- The full distinguished name of the cert.
//  "subjectDN_withTags" -- Same as above, but in a format that includes the subject part tags, such as the "CN=" in "CN=something"
//  "subjectCN" -- The common name part (CN) of the certificate's subject.
//  "serial" -- The certificate serial number.
//  "serial:issuerCN" -- The certificate serial number + the issuer's common name, delimited with a colon char.
//  These are the same certificate parts that can be retrieved by listing certificates on the smart card (or USB token).
//  See List Certificates on Smart Card Example
cCertPart := "subjectCN"
cPartValue := "PIVKey E42D60A759D39147A26E0AF2FB1183C5"

//  If the certificate is found, it is loaded into the cert object.
oCert := CreateObject("Chilkat.Cert")
nSuccess := oScmd:FindCert(cCertPart, cPartValue, oCert)
IF (nSuccess == 0)
    ? "Failed to find the certificate."
    oScmd:DeleteContext()
    oScmd:destroy()
    oCert:destroy()
    RETURN
ENDIF

? "Successfully loaded the cert object from the smart card / USB token."

//  Note: When successful, the cert object is internally linked to the ScMinidriver object's authenticated session.
//  The cert object can now be used to sign or do other cryptographic operations that occur on the smart card / USB token.
//  If your application calls PinDeauthenticate or DeleteContext, the cert will no longer be able to sign on the smart card
//  because the smart card ScMinidriver session will no longer be authenticated or deleted.

//  ------------------------------------------------------------------------------------------------------------
//  We have the certificate.  Now let's do the XML digital signature..

//  Create the following XML to be signed:

//  <?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>

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

//  Prepare for signing...
oGen := CreateObject("Chilkat.XmlDSigGen")

//  Indicate where the Signature will be inserted.
oGen: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"
oGen:AddSameDocRef("Body", "sha1", "EXCL_C14N", "", "")

//  (You can read about the SignedInfoPrefixList in the online reference documentation.  It's optional..)
oGen: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.
oGen:KeyInfoType := "X509Data"
oGen:X509Type := "Certificate"

//  Note: Our certificate was loaded from the smartcard and is internally linked to the authenticated ScMinidriver session.
//  The signing will occur on the smart card using the chosen certificate.
nBUsePrivateKey := 1
nSuccess := oGen:SetX509Cert(oCert, nBUsePrivateKey)
IF (nSuccess != 1)
    ? oGen:LastErrorText
    oScmd:destroy()
    oCert:destroy()
    oXml:destroy()
    oGen:destroy()
    RETURN
ENDIF

//  Everything's specified.  Now create and insert the Signature
oSbXml := CreateObject("Chilkat.StringBuilder")
oXml:GetXmlSb(oSbXml)
nSuccess := oGen:CreateXmlDSigSb(oSbXml)
IF (nSuccess != 1)
    ? oGen:LastErrorText
    oScmd:destroy()
    oCert:destroy()
    oXml:destroy()
    oGen:destroy()
    oSbXml:destroy()
    RETURN
ENDIF

//  Examine the XML with the digital signature inserted
? oSbXml:GetAsString()

//  ------------------------------------------------------------------------------------------------------------
//  Cleanup our ScMinidriver session...

//  When finished with operations that required authentication, you may if you wish, deauthenticate the session.
nSuccess := oScmd:PinDeauthenticate("user")
IF (nSuccess == 0)
    ? oScmd:LastErrorText
ENDIF

//  Delete the context when finished with the card.
nSuccess := oScmd:DeleteContext()
IF (nSuccess == 0)
    ? oScmd:LastErrorText
ENDIF

oScmd:destroy()
oCert:destroy()
oXml:destroy()
oGen:destroy()
oSbXml:destroy()