(C) Create XML Digital Signature using Certificate on Smart Card

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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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#include <C_CkScMinidriver.h>
#include <C_CkCert.h>
#include <C_CkXml.h>
#include <C_CkXmlDSigGen.h>
#include <C_CkStringBuilder.h>

void ChilkatSample(void)
    {
    HCkScMinidriver scmd;
    const char *readerName;
    BOOL success;
    int retval;
    const char *certPart;
    const char *partValue;
    HCkCert cert;
    HCkXml xml;
    HCkXmlDSigGen gen;
    BOOL bUsePrivateKey;
    HCkStringBuilder sbXml;

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

    scmd = CkScMinidriver_Create();

    // Reader names (smart card readers or USB tokens) can be discovered
    // via List Readers or Find Smart Cards
    readerName = "SCM Microsystems Inc. SCR33x USB Smart Card Reader 0";
    success = CkScMinidriver_AcquireContext(scmd,readerName);
    if (success == FALSE) {
        printf("%s\n",CkScMinidriver_lastErrorText(scmd));
        CkScMinidriver_Dispose(scmd);
        return;
    }

    // If successful, the name of the currently inserted smart card is available:
    printf("Card name: %s\n",CkScMinidriver_cardName(scmd));

    // If desired, perform regular PIN authentication with the smartcard.
    // For more details about smart card PIN authentication, see the Smart Card PIN Authentication Example
    retval = CkScMinidriver_PinAuthenticate(scmd,"user","000000");
    if (retval != 0) {
        printf("PIN Authentication failed.\n");
    }

    // 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
    certPart = "subjectCN";
    partValue = "PIVKey E42D60A759D39147A26E0AF2FB1183C5";

    // If the certificate is found, it is loaded into the cert object.
    cert = CkCert_Create();
    success = CkScMinidriver_FindCert(scmd,certPart,partValue,cert);
    if (success == FALSE) {
        printf("Failed to find the certificate.\n");
        CkScMinidriver_DeleteContext(scmd);
        CkScMinidriver_Dispose(scmd);
        CkCert_Dispose(cert);
        return;
    }

    printf("Successfully loaded the cert object from the smart card / USB token.\n");

    // 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>

    xml = CkXml_Create();
    CkXml_putTag(xml,"SOAP-ENV:Envelope");
    CkXml_AddAttribute(xml,"xmlns:SOAP-ENV","http://schemas.xmlsoap.org/soap/envelope/");
    CkXml_UpdateAttrAt(xml,"SOAP-ENV:Header|wsse:Security",TRUE,"xmlns:wsse","http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd");
    CkXml_UpdateAttrAt(xml,"SOAP-ENV:Header|wsse:Security",TRUE,"SOAP-ENV:mustUnderstand","1");
    CkXml_UpdateAttrAt(xml,"SOAP-ENV:Body",TRUE,"xmlns:SOAP-SEC","http://schemas.xmlsoap.org/soap/security/2000-12");
    CkXml_UpdateAttrAt(xml,"SOAP-ENV:Body",TRUE,"SOAP-SEC:id","Body");
    CkXml_UpdateAttrAt(xml,"SOAP-ENV:Body|z:FooBar",TRUE,"xmlns:z","http://example.com");

    // Prepare for signing...
    gen = CkXmlDSigGen_Create();

    // Indicate where the Signature will be inserted.
    CkXmlDSigGen_putSigLocation(gen,"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"
    CkXmlDSigGen_AddSameDocRef(gen,"Body","sha1","EXCL_C14N","","");

    // (You can read about the SignedInfoPrefixList in the online reference documentation.  It's optional..)
    CkXmlDSigGen_putSignedInfoPrefixList(gen,"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.
    CkXmlDSigGen_putKeyInfoType(gen,"X509Data");
    CkXmlDSigGen_putX509Type(gen,"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.
    bUsePrivateKey = TRUE;
    success = CkXmlDSigGen_SetX509Cert(gen,cert,bUsePrivateKey);
    if (success != TRUE) {
        printf("%s\n",CkXmlDSigGen_lastErrorText(gen));
        CkScMinidriver_Dispose(scmd);
        CkCert_Dispose(cert);
        CkXml_Dispose(xml);
        CkXmlDSigGen_Dispose(gen);
        return;
    }

    // Everything's specified.  Now create and insert the Signature
    sbXml = CkStringBuilder_Create();
    CkXml_GetXmlSb(xml,sbXml);
    success = CkXmlDSigGen_CreateXmlDSigSb(gen,sbXml);
    if (success != TRUE) {
        printf("%s\n",CkXmlDSigGen_lastErrorText(gen));
        CkScMinidriver_Dispose(scmd);
        CkCert_Dispose(cert);
        CkXml_Dispose(xml);
        CkXmlDSigGen_Dispose(gen);
        CkStringBuilder_Dispose(sbXml);
        return;
    }

    // Examine the XML with the digital signature inserted
    printf("%s\n",CkStringBuilder_getAsString(sbXml));

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

    // When finished with operations that required authentication, you may if you wish, deauthenticate the session.
    success = CkScMinidriver_PinDeauthenticate(scmd,"user");
    if (success == FALSE) {
        printf("%s\n",CkScMinidriver_lastErrorText(scmd));
    }

    // Delete the context when finished with the card.
    success = CkScMinidriver_DeleteContext(scmd);
    if (success == FALSE) {
        printf("%s\n",CkScMinidriver_lastErrorText(scmd));
    }



    CkScMinidriver_Dispose(scmd);
    CkCert_Dispose(cert);
    CkXml_Dispose(xml);
    CkXmlDSigGen_Dispose(gen);
    CkStringBuilder_Dispose(sbXml);

    }