How to use the saml.server.signature function in saml

$scope.save = function() {
        if ($scope.newRedirectUri && $scope.newRedirectUri.length > 0) {
            $scope.addRedirectUri();
        }

        if ($scope.newWebOrigin && $scope.newWebOrigin.length > 0) {
            $scope.addWebOrigin();
        }

        if ($scope.samlServerSignature == true) {
            $scope.clientEdit.attributes["saml.server.signature"] = "true";
        } else {
            $scope.clientEdit.attributes["saml.server.signature"] = "false";
        }
        if ($scope.samlServerSignatureEnableKeyInfoExtension == true) {
            $scope.clientEdit.attributes["saml.server.signature.keyinfo.ext"] = "true";
        } else {
            $scope.clientEdit.attributes["saml.server.signature.keyinfo.ext"] = "false";
        }
        if ($scope.samlAssertionSignature == true) {
            $scope.clientEdit.attributes["saml.assertion.signature"] = "true";
        } else {
            $scope.clientEdit.attributes["saml.assertion.signature"] = "false";
        }
        if ($scope.samlClientSignature == true) {
            $scope.clientEdit.attributes["saml.client.signature"] = "true";
        } else {
            $scope.clientEdit.attributes["saml.client.signature"] = "false";

} else if ($scope.client.attributes['saml.signature.algorithm'] == 'RSA_SHA512') {
            $scope.signatureAlgorithm = $scope.signatureAlgorithms[2];
        } else if ($scope.client.attributes['saml.signature.algorithm'] == 'DSA_SHA1') {
            $scope.signatureAlgorithm = $scope.signatureAlgorithms[3];
        }
        if ($scope.client.attributes['saml_name_id_format'] == 'username') {
            $scope.nameIdFormat = $scope.nameIdFormats[0];
        } else if ($scope.client.attributes['saml_name_id_format'] == 'email') {
            $scope.nameIdFormat = $scope.nameIdFormats[1];
        } else if ($scope.client.attributes['saml_name_id_format'] == 'transient') {
            $scope.nameIdFormat = $scope.nameIdFormats[2];
        } else if ($scope.client.attributes['saml_name_id_format'] == 'persistent') {
            $scope.nameIdFormat = $scope.nameIdFormats[3];
        }
        if ($scope.client.attributes["saml.server.signature"]) {
            if ($scope.client.attributes["saml.server.signature"] == "true") {
                $scope.samlServerSignature = true;
            } else {
                $scope.samlServerSignature = false;

            }
        }
        if ($scope.client.attributes["saml.server.signature.keyinfo.ext"]) {
            if ($scope.client.attributes["saml.server.signature.keyinfo.ext"] == "true") {
                $scope.samlServerSignatureEnableKeyInfoExtension = true;
            } else {
                $scope.samlServerSignatureEnableKeyInfoExtension = false;
            }
        }
        if ($scope.client.attributes['saml.server.signature.keyinfo.xmlSigKeyInfoKeyNameTransformer'] === 'NONE') {
            $scope.samlXmlKeyNameTranformer = $scope.xmlKeyNameTranformers[0];
        } else if ($scope.client.attributes['saml.server.signature.keyinfo.xmlSigKeyInfoKeyNameTransformer'] === 'KEY_ID') {