(C) Add EncapsulatedTimestamp to Already-Signed XML

See more XML Digital Signatures Examples

Demonstrates how to add an EncapsulatedTimestamp to an existing XML signature.

Note: This example requires Chilkat v9.5.0.90 or greater.

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#include <C_CkStringBuilder.h>
#include <C_CkXmlDSig.h>
#include <C_CkJsonObject.h>

void ChilkatSample(void)
    {
    HCkStringBuilder sbXml;
    BOOL success;
    HCkXmlDSig dsig;
    HCkJsonObject json;
    HCkStringBuilder sbOut;
    HCkXmlDSig verifier;
    int numSigs;
    int verifyIdx;
    BOOL verified;

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

    // Note: We cannot load the already-signed XML into a Chilkat XML object because it would re-format the XML when re-emitted.
    // (i.e. indentation and whitespace could change, and it would invalidate the existing signature.)
    // We must use a StringBuilder.
    sbXml = CkStringBuilder_Create();
    success = CkStringBuilder_LoadFile(sbXml,"qa_data/xml_dsig_valid_samples/encapsulatedTimestamp_not_yet_added.xml","utf-8");
    if (success == FALSE) {
        printf("Failed to load the XML file.\n");
        CkStringBuilder_Dispose(sbXml);
        return;
    }

    dsig = CkXmlDSig_Create();
    success = CkXmlDSig_LoadSignatureSb(dsig,sbXml);
    if (success == FALSE) {
        printf("%s\n",CkXmlDSig_lastErrorText(dsig));
        CkStringBuilder_Dispose(sbXml);
        CkXmlDSig_Dispose(dsig);
        return;
    }

    if (CkXmlDSig_HasEncapsulatedTimeStamp(dsig) == TRUE) {
        printf("This signed XML already has an EncapsulatedTimeStamp\n");
        CkStringBuilder_Dispose(sbXml);
        CkXmlDSig_Dispose(dsig);
        return;
    }

    // Specify the timestamping authority URL
    json = CkJsonObject_Create();
    CkJsonObject_UpdateString(json,"timestampToken.tsaUrl","http://timestamp.digicert.com");
    CkJsonObject_UpdateBool(json,"timestampToken.requestTsaCert",TRUE);

    // Call AddEncapsulatedTimeStamp to add the EncapsulatedTimeStamp to the signature.
    // Note: If the signed XML contains multiple signatures, the signature modified is the one 
    // indicated by the dsig.Selector property.
    sbOut = CkStringBuilder_Create();
    success = CkXmlDSig_AddEncapsulatedTimeStamp(dsig,json,sbOut);
    if (success == FALSE) {
        printf("%s\n",CkXmlDSig_lastErrorText(dsig));
        CkStringBuilder_Dispose(sbXml);
        CkXmlDSig_Dispose(dsig);
        CkJsonObject_Dispose(json);
        CkStringBuilder_Dispose(sbOut);
        return;
    }

    CkStringBuilder_WriteFile(sbOut,"qa_output/addedEncapsulatedTimeStamp.xml","utf-8",FALSE);

    // The EncapsulatedTimeStamp can be validated when validating the signature by adding the VerifyEncapsulatedTimeStamp
    // keyword to UncommonOptions.  See here:

    // ----------------------------------------
    // Verify the signatures we just produced...
    verifier = CkXmlDSig_Create();
    success = CkXmlDSig_LoadSignatureSb(verifier,sbOut);
    if (success != TRUE) {
        printf("%s\n",CkXmlDSig_lastErrorText(verifier));
        CkStringBuilder_Dispose(sbXml);
        CkXmlDSig_Dispose(dsig);
        CkJsonObject_Dispose(json);
        CkStringBuilder_Dispose(sbOut);
        CkXmlDSig_Dispose(verifier);
        return;
    }

    // Add "VerifyEncapsulatedTimeStamp" to the UncommonOptions to also verify any EncapsulatedTimeStamps
    CkXmlDSig_putUncommonOptions(verifier,"VerifyEncapsulatedTimeStamp");

    numSigs = CkXmlDSig_getNumSignatures(verifier);
    verifyIdx = 0;
    while (verifyIdx < numSigs) {
        CkXmlDSig_putSelector(verifier,verifyIdx);
        verified = CkXmlDSig_VerifySignature(verifier,TRUE);
        if (verified != TRUE) {
            printf("%s\n",CkXmlDSig_lastErrorText(verifier));
            CkStringBuilder_Dispose(sbXml);
            CkXmlDSig_Dispose(dsig);
            CkJsonObject_Dispose(json);
            CkStringBuilder_Dispose(sbOut);
            CkXmlDSig_Dispose(verifier);
            return;
        }

        verifyIdx = verifyIdx + 1;
    }

    printf("All signatures were successfully verified.\n");


    CkStringBuilder_Dispose(sbXml);
    CkXmlDSig_Dispose(dsig);
    CkJsonObject_Dispose(json);
    CkStringBuilder_Dispose(sbOut);
    CkXmlDSig_Dispose(verifier);

    }