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

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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.

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#include <C_CkPkcs11.h>
#include <C_CkCert.h>
#include <C_CkXml.h>
#include <C_CkXmlDSigGen.h>
#include <C_CkStringBuilder.h>

void ChilkatSample(void)
    {
    HCkPkcs11 pkcs11;
    int userType;
    const char *pin;
    BOOL success;
    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.

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

    pkcs11 = CkPkcs11_Create();

    // 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.
    CkPkcs11_putSharedLibPath(pkcs11,"aetpkss1.dll");

    // Make it an authenticated session by calling Login.
    userType = 1;
    // Make sure to use the correct PIN for your smart card..
    pin = "0000";

    success = CkPkcs11_QuickSession(pkcs11,userType,pin);
    if (success == FALSE) {
        printf("%s\n",CkPkcs11_lastErrorText(pkcs11));
        CkPkcs11_Dispose(pkcs11);
        return;
    }

    // Get the certificate (on the smart card) that has a private key.
    cert = CkCert_Create();
    success = CkPkcs11_FindCert(pkcs11,"privateKey","",cert);
    if (success == TRUE) {
        printf("Cert with private key: %s\n",CkCert_subjectCN(cert));
    }
    else {
        printf("No certificates having a private key were found.\n");
        success = CkPkcs11_CloseSession(pkcs11);
        CkPkcs11_Dispose(pkcs11);
        CkCert_Dispose(cert);
        return;
    }

    // --------------------------------------------------------------------------
    // 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>

    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");

    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");

    bUsePrivateKey = TRUE;
    success = CkXmlDSigGen_SetX509Cert(gen,cert,bUsePrivateKey);
    if (success != TRUE) {
        printf("%s\n",CkXmlDSigGen_lastErrorText(gen));
        success = CkPkcs11_CloseSession(pkcs11);
        CkPkcs11_Dispose(pkcs11);
        CkCert_Dispose(cert);
        CkXml_Dispose(xml);
        CkXmlDSigGen_Dispose(gen);
        return;
    }

    // Everything's specified.  Now create and insert the Signature
    sbXml = CkStringBuilder_Create();
    CkXml_putEmitCompact(xml,TRUE);
    CkXml_GetXmlSb(xml,sbXml);

    success = CkXmlDSigGen_CreateXmlDSigSb(gen,sbXml);
    if (success != TRUE) {
        printf("%s\n",CkXmlDSigGen_lastErrorText(gen));
        success = CkPkcs11_CloseSession(pkcs11);
        CkPkcs11_Dispose(pkcs11);
        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));

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

    // Revert to an unauthenticated session by calling Logout.
    success = CkPkcs11_Logout(pkcs11);
    if (success == FALSE) {
        printf("%s\n",CkPkcs11_lastErrorText(pkcs11));
        success = CkPkcs11_CloseSession(pkcs11);
        CkPkcs11_Dispose(pkcs11);
        CkCert_Dispose(cert);
        CkXml_Dispose(xml);
        CkXmlDSigGen_Dispose(gen);
        CkStringBuilder_Dispose(sbXml);
        return;
    }

    // When finished, close the session.
    // It is important to close the session (memory leaks will occur if the session is not properly closed).
    success = CkPkcs11_CloseSession(pkcs11);
    if (success == FALSE) {
        printf("%s\n",CkPkcs11_lastErrorText(pkcs11));
        CkPkcs11_Dispose(pkcs11);
        CkCert_Dispose(cert);
        CkXml_Dispose(xml);
        CkXmlDSigGen_Dispose(gen);
        CkStringBuilder_Dispose(sbXml);
        return;
    }

    printf("Success.\n");


    CkPkcs11_Dispose(pkcs11);
    CkCert_Dispose(cert);
    CkXml_Dispose(xml);
    CkXmlDSigGen_Dispose(gen);
    CkStringBuilder_Dispose(sbXml);

    }