Como extrair chave pública da Signature xml

Bom dia, estou precisando extrair chave pública assinada do xml, será que alguém poderia me dar o caminho ou alguns material?


<Signature xmlns="http://www.w3.org/2000/09/xmldsig#">
<SignedInfo>
<CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
<SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
<Reference URI="#NFSE_123">
<Transforms><Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/>
<Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
</Transforms>
<DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
<DigestValue>
</DigestValue>
</Reference>
</SignedInfo>
<SignatureValue>


</X509Certificate>
</X509Data>
</KeyInfo>
</Signature>