Verify Java SAML Signature from C #

Question

How can I verify in .Net C # the SAML signature created in Java? Here is the SAML signature I get from Java:

<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:CanonicalizationMethod> <ds:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"> </ds:SignatureMethod> <ds:Reference URI="#_e8bcba9d1c76d128938bddd5ae8c68e1"> <ds:Transforms> <ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"> </ds:Transform> <ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"> <ec:InclusiveNamespaces xmlns:ec="http://www.w3.org/2001/10/xml-exc-c14n#" PrefixList="code ds kind rw saml samlp typens #default xsd xsi"> </ec:InclusiveNamespaces> </ds:Transform> </ds:Transforms> <ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"> </ds:DigestMethod> <ds:DigestValue>zEL7mB0Wkl+LtjMViO1imbucXiE=</ds:DigestValue> </ds:Reference> </ds:SignedInfo> <ds:SignatureValue> jpIX3WbX9SCFnqrpDyLj4TeJN5DGIvlEH+o/mb9M01VGdgFRLtfHqIm16BloApUPg2dDafmc9DwL Pyvs3TJ/hi0Q8f0ucaKdIuw+gBGxWFMcj/U68ZuLiv7U+Qe7i4ZA33rWPorkE82yfMacGf6ropPt v73mC0bpBP1ubo5qbM4= </ds:SignatureValue> <ds:KeyInfo> <ds:X509Data> <ds:X509Certificate> MIIDBDCCAeygAwIBAgIIC/ktBs1lgYcwDQYJKoZIhvcNAQEFBQAwNzERMA8GA1UEAwwIQWRtaW5D QTExFTATBgNVBAoMDEVKQkNBIFNhbXBsZTELMAkGA1UEBhMCU0UwHhcNMDkwMjIzMTAwMzEzWhcN MTgxMDE1MDkyNTQyWjBaMRQwEgYDVQQDDAsxMC41NS40MC42MTEbMBkGA1UECwwST24gRGVtYW5k IFBsYXRmb3JtMRIwEAYDVQQLDAlPbiBEZW1hbmQxETAPBgNVBAsMCFNvZnR3YXJlMIGfMA0GCSqG SIb3DQEBAQUAA4GNADCBiQKBgQCk5EqiedxA6WEE9N2vegSCqleFpXMfGplkrcPOdXTRLLOuRgQJ LEsOaqspDFoqk7yJgr7kaQROjB9OicSH7Hhsu7HbdD6N3ntwQYoeNZ8nvLSSx4jz21zvswxAqw1p DoGl3J6hks5owL4eYs2yRHvqgqXyZoxCccYwc4fYzMi42wIDAQABo3UwczAdBgNVHQ4EFgQUkrpk yryZToKXOXuiU2hNsKXLbyIwDAYDVR0TAQH/BAIwADAfBgNVHSMEGDAWgBSiviFUK7DUsjvByMfK g+pm4b2s7DAOBgNVHQ8BAf8EBAMCBaAwEwYDVR0lBAwwCgYIKwYBBQUHAwEwDQYJKoZIhvcNAQEF BQADggEBAKb94tnK2obEyvw8ZJ87u7gvkMxIezpBi/SqXTEBK1by0NHs8VJmdDN9+aOvC5np4fOL fFcRH++n6fvemEGgIkK3pOmNL5WiPpbWxrx55Yqwnr6eLsbdATALE4cgyZWHl/E0uVO2Ixlqeygw XTfg450cCWj4yfPTVZ73raKaDTWZK/Tnt7+ulm8xN+YWUIIbtW3KBQbGomqOzpftALyIKLVtBq7L J0hgsKGHNUnssWj5dt3bYrHgzaWLlpW3ikdRd67Nf0c1zOEgKHNEozrtRKiLLy+3bIiFk0CHImac 1zeqLlhjrG3OmIsIjxc1Vbc0+E+z6Unco474oSGf+D1DO+Y= </ds:X509Certificate> </ds:X509Data> </ds:KeyInfo> </ds:Signature> 

I know that I need to parse SAML, I need to verify the signature. I tried this:

 public bool VerifySignature() { X509Certificate2 certificate = null; XmlDocument doc = new XmlDocument(); XmlElement xmlAssertionElement = this.GetXml(doc); doc.AppendChild(xmlAssertionElement); // Create a new SignedXml object and pass it // the XML document class. SamlSignedXml signedXml = new SamlSignedXml(xmlAssertionElement); // Get signature XmlElement xmlSignature = this.Signature; if (xmlSignature == null) { return false; } // Load the signature node. signedXml.LoadXml(xmlSignature); // Get the certificate used to sign the assertion if information about this // certificate is available in the signature of the assertion. foreach (KeyInfoClause clause in signedXml.KeyInfo) { if (clause is KeyInfoX509Data) { if (((KeyInfoX509Data)clause).Certificates.Count > 0) { certificate = (X509Certificate2)((KeyInfoX509Data)clause).Certificates[0]; } } } if (certificate == null) { return false; } return signedXml.CheckSignature(certificate, true); } 

It verifies the signature of a SAML signed in .Net, but not that Java.

Answer 1

Solved the problem with the answers in this thread: http://social.msdn.microsoft.com/Forums/en-US/wcf/thread/faf0b66c-294b-4d84-a19b-504dd8e81922 My code was very similar to the examples from MSDN shown there, only the missing was: doc.PreserveWhitespace = true when checking.

Answer 2

You can use the classes in the System.Security.Cryptography.Xml to validate digitally signed XML data, provided that you have the public key in your certificate store. I did a bit of work with AD federation services, which also use SAML, and as far as I remember, after finding the namespace I needed, the rest was pretty simple - but it's been a while that the details go away from me.