XMLSec Library

XML Digital Signature

XML Signatures provides integrity , message authentication , and/or signer authentication services for data of any type, whether located within the XML that includes the signature or elsewhere.   XMLSec Library supports all MUST/SHOULD/MAY features and algorithms described in the W3C standard and provides API to sign prepared document templates, add signature(s) to a document "on-the-fly" or verify the signature(s) in the document.

If you have an XML document signed with XML Signature you can verify it using the online tool .