C#

SAML Signature Validation

See more XML Digital Signatures Examples

A SAML Signature is an XML Digital Signature (XMLDSig) just like any other XML digital signature. It can be verified by using Chilkat' XmlDSig class, as shown in this example. C#

bool success = false;

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

Chilkat.XmlDSig dsig = new Chilkat.XmlDSig();
success = dsig.LoadSignature("XML xml signature goes here...");

//  A sample SAML signature is shown below..

int numSignatures = dsig.NumSignatures;
int i = 0;
while (i < numSignatures) {
    dsig.Selector = i;

    bool bVerifyRefDigests = false;
    bool bSignatureVerified = dsig.VerifySignature(bVerifyRefDigests);
    if (bSignatureVerified == true) {
        Debug.WriteLine("Signature " + Convert.ToString(i + 1) + " verified");
    }
    else {
        Debug.WriteLine("Signature " + Convert.ToString(i + 1) + " invalid");
    }

    //  Check each of the reference digests separately..
    int numRefDigests = dsig.NumReferences;
    int j = 0;
    while (j < numRefDigests) {
        bool bDigestVerified = dsig.VerifyReferenceDigest(j);
        Debug.WriteLine("reference digest " + Convert.ToString(j + 1) + " verified = " + Convert.ToString(bDigestVerified));
        if (bDigestVerified == false) {
            Debug.WriteLine("    reference digest fail reason: " + Convert.ToString(dsig.RefFailReason));
        }

        j = j + 1;
    }

    i = i + 1;
}

//  --------------------------------------
//  Here is a sample SAML XML Signature
//  
//  
//  <?xml version="1.0" encoding="UTF-8"?>
//  <saml2p:Response xmlns:saml2p="urn:oasis:names:tc:SAML:2.0:protocol" ID="abc123" Version="2.0" IssueInstant="2022-04-01T12:34:56Z" Destination="https://sp.example.com/sso">
//    <saml2:Issuer xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion">https://idp.example.com</saml2:Issuer>
//    <saml2p:Status>
//      <saml2p:StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:Success"/>
//    </saml2p:Status>
//    <saml2:Assertion xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion" ID="def456" IssueInstant="2022-04-01T12:34:56Z" Version="2.0">
//      <saml2:Issuer>https://idp.example.com</saml2:Issuer>
//      <saml2:Subject>
//        <saml2:NameID Format="urn:oasis:names:tc:SAML:1.1:nameid-format:emailAddress">user@example.com</saml2:NameID>
//      </saml2:Subject>
//      <saml2:Conditions NotBefore="2022-04-01T12:34:56Z" NotOnOrAfter="2022-04-01T13:34:56Z"/>
//      <saml2:AuthnStatement AuthnInstant="2022-04-01T12:34:56Z">
//        <saml2:AuthnContext>
//          <saml2:AuthnContextClassRef>urn:oasis:names:tc:SAML:2.0:ac:classes:Password</saml2:AuthnContextClassRef>
//        </saml2:AuthnContext>
//      </saml2:AuthnStatement>
//      <!-- Additional assertion content -->
//    </saml2:Assertion>
//    <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
//      <ds:SignedInfo>
//        <ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/>
//        <ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#rsa-sha256"/>
//        <ds:Reference URI="#abc123">
//          <ds:Transforms>
//            <ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/>
//            <ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/>
//          </ds:Transforms>
//          <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
//          <ds:DigestValue>q7Zj1w+...+pCsjw=</ds:DigestValue>
//        </ds:Reference>
//        <!-- Additional references if present -->
//      </ds:SignedInfo>
//      <ds:SignatureValue>
//        NjIzOWE5ZjA2M2M1...NzUwNzUwNzUwNzUwNzU=
//      </ds:SignatureValue>
//      <ds:KeyInfo>
//        <ds:X509Data>
//          <ds:X509Certificate>
//            MIIDgzCCAmugAwIBAg...AgADAA==
//          </ds:X509Certificate>
//        </ds:X509Data>
//      </ds:KeyInfo>
//    </ds:Signature>
//  </saml2p:Response>