private boolean isCertificateFromTrustedIssuer(final X509Certificate cert) {
        return doesNameMatchPattern(cert.getIssuerDN(), this.regExTrustedIssuerDnPattern);
    }
Checks if is certificate from trusted issuer based on the regex pattern.

@param cert the cert
@return true, if  certificate from trusted issuer
support/cas-server-support-x509-core/src/main/java/org/apereo/cas/adaptors/x509/authentication/handler/support/X509CredentialsAuthenticationHandler.java