Go

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. Go

    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.
    http := chilkat.NewHttp()
    sbXml := chilkat.NewStringBuilder()
    success = http.QuickGetSb("https://www.chilkatsoft.com/exampleData/envelopedMultipleRefs.xml",sbXml)
    if success != true {
        fmt.Println(http.LastErrorText())
        http.DisposeHttp()
        sbXml.DisposeStringBuilder()
        return
    }

    // Load the XML containing the signature to be verified.
    verifier := chilkat.NewXmlDSig()
    success = verifier.LoadSignatureSb(sbXml)
    if success != true {
        fmt.Println(verifier.LastErrorText())
        http.DisposeHttp()
        sbXml.DisposeStringBuilder()
        verifier.DisposeXmlDSig()
        return
    }

    verifyReferenceDigests := true

    // The quick way to validate all references and the signature over the SignedInfo
    // is to call VerifySignature with verifyReferenceDigests equal to true.
    verified := verifier.VerifySignature(verifyReferenceDigests)
    fmt.Println("Signature and all reference digests verified = ", 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
    signedInfoVerified := verifier.VerifySignature(verifyReferenceDigests)
    fmt.Println("Neglecting the reference hashes, the SignedInfo validation result = ", signedInfoVerified)

    // We can also verify each reference digest separately
    numRefs := verifier.NumReferences()
    i := 0
    for i < numRefs {
        refDigestVerified := verifier.VerifyReferenceDigest(i)
        fmt.Println("Reference ", i, " digest verified = ", 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 = Tru

    http.DisposeHttp()
    sbXml.DisposeStringBuilder()
    verifier.DisposeXmlDSig()