Unicode C++

Verify an XML Signature with Multiple References

See more XML Digital Signatures Examples

Demonstrates how to verify an XML digital signature that contains multiple references. Unicode C++

#include <CkHttpW.h>
#include <CkStringBuilderW.h>
#include <CkXmlDSigW.h>

void ChilkatSample(void)
    {
    bool success = false;

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

    //  An example of an enveloping XML signature with mulitple references is available at
    //  https://www.chilkatsoft.com/exampleData/envelopedMultipleRefs.xml

    //  This example will show how to verify the signature and all references, and also how
    //  to verify each reference individually.  This is useful to distinguish which part
    //  of the XML signature validation failed.  It could be that one or more of the references
    //  failed because of a hash computation mismatch.  Or it could be that the signature over
    //  the SignedInfo failed.  

    //  First, let's grab the sample XML signature.
    CkHttpW http;
    CkStringBuilderW sbXml;
    success = http.QuickGetSb(L"https://www.chilkatsoft.com/exampleData/envelopedMultipleRefs.xml",sbXml);
    if (success != true) {
        wprintf(L"%s\n",http.lastErrorText());
        return;
    }

    //  Load the XML containing the signature to be verified.
    CkXmlDSigW verifier;
    success = verifier.LoadSignatureSb(sbXml);
    if (success != true) {
        wprintf(L"%s\n",verifier.lastErrorText());
        return;
    }

    bool verifyReferenceDigests = true;

    //  The quick way to validate all references and the signature over the SignedInfo
    //  is to call VerifySignature with verifyReferenceDigests equal to true.
    bool verified = verifier.VerifySignature(verifyReferenceDigests);
    wprintf(L"Signature and all reference digests verified = %d\n",verified);

    //  Let's pretend the call to VerifySignature returned false.  Something did not validate.
    //  Was it one or more of the References that did not hash to the correct value?
    //  Or was it the signature over the SignedInfo that failed?
    //  We can check just the signature over the SignedInfo by passing false to VerifySignature.
    //  This allows us to skip the hashing and checking each Reference.  
    verifyReferenceDigests = false;
    bool signedInfoVerified = verifier.VerifySignature(verifyReferenceDigests);
    wprintf(L"Neglecting the reference hashes, the SignedInfo validation result = %d\n",signedInfoVerified);

    //  We can also verify each reference digest separately
    int numRefs = verifier.get_NumReferences();
    int i = 0;
    while (i < numRefs) {
        bool refDigestVerified = verifier.VerifyReferenceDigest(i);
        wprintf(L"Reference %d digest verified = %d\n",i,refDigestVerified);
        i = i + 1;
    }

    //  For this sample XML signature with 3 References, we get the following output:

    //  Signature and all reference digests verified = True
    //  Neglecting the reference hashes, the SignedInfo validation result = True
    //  Reference 0 digest verified = True
    //  Reference 1 digest verified = True
    //  Reference 2 digest verified = True
    }