title: How can I specify a SHA-256 algorithm for signing the certificate?
body: <p>I built an Apereo CAS demo server with a WAR overlay (with which
  different services should be authenticated).</p>
  <p>I have set up delegated authentication with SAML2 (for integrating
  with italian SPID system), following this guide
  <a href="https://apereo.github.io/2019/02/25/cas61-delegate-authn-saml2-idp/" rel="nofollow noreferrer">https://apereo.github.io/2019/02/25/cas61-delegate-authn-saml2-idp/</a></p>
  <p>I copied the SP metadata to a IDP configuration.
  This IDP is a test IDP instance, meant to check if SP metadata and the SAML request are ok.</p>
  <p>When I run the server and I browse it,
  I can see the second login form, but when I click it, the validation checks shows some errors.
  Among them there is the following:</p>
  <pre><code>&quot;The certificate must be signed with a valid algorithm.&quot;
  &quot;The certificate must not be signed using the SHA1 algorithm (deprecated).&quot;
  </code></pre>
  <p>I am pretty sure that SHA-256 would be fine with the IDP validator.</p>
  <p>In the documentation
  <a href="https://apereo.github.io/cas/development/integration/Delegate-Authentication-SAML.html" rel="nofollow noreferrer">https://apereo.github.io/cas/development/integration/Delegate-Authentication-SAML.html</a>
  I see that the following parameter should be in charge of specifying
  the signing certificate algorithm:</p>
  <pre><code>cas.authn.pac4j.saml[].signature-algorithms:
  </code></pre>
  <p>Its description is</p>
  <pre><code># Required: false
  # Type: java.util.List&lt;String&gt;
  # Owner: org.apereo.cas.configuration.model.support.pac4j.saml.Pac4jSamlClientProperties
  # Module: cas-server-support-pac4j-webflow
  # Collection of signing signature algorithms, if any, to override the global defaults.
  # cas.authn.pac4j.saml[].signature-algorithms: 
  </code></pre>
  <p>I don't know what values are allowed there. I googled a lot but with no luck.</p>
  <p>I have tried to set that list like this
  <code>cas.authn.pac4j.saml[0].signature-algorithms=[&quot;sha256WithRSAEncryption&quot;]</code>,
  <code>cas.authn.pac4j.saml[0].signature-algorithms=[&quot;SHA256withRSA&quot;]</code> but,
  after clicking the SAML login button, I always get the following
  error:</p>
  <pre><code>org.pac4j.saml.exceptions.SAMLException: org.pac4j.saml.exceptions.SAMLException: Could not determine the signature parameters
      at org.pac4j.saml.crypto.DefaultSignatureSigningParametersProvider.build(DefaultSignatureSigningParametersProvider.java:60)
      ...
  </code></pre>
  <p>How can I specify a SHA-256 algorithm for signing the certificate?</p>