@@ -82,6 +82,7 @@ When the application has started, open the _ngrok_ HTTPS URL in your preferred w
     - [Using DigiDoc4j in production mode with the `prod` profile](#using-digidoc4j-in-production-mode-with-the-prod-profile)
   + [Stateful and stateless authentication](#stateful-and-stateless-authentication)
   + [Assuring that the signing and authentication certificate subjects match](#assuring-that-the-signing-and-authentication-certificate-subjects-match)
+  + [Requesting the signing certificate in a separate step](#requesting-the-signing-certificate-in-a-separate-step)
 * [HTTPS support](#https-support)
   + [How to verify that HTTPS is configured properly](#how-to-verify-that-https-is-configured-properly)
 * [Deployment](#deployment)
@@ -119,7 +120,9 @@ The `src/main/java/eu/webeid/example` directory contains the Spring Boot applica
     -   `WebEidChallengeNonceFilter` for issuing the challenge nonce required by the authentication flow,
     -   `WebEidMobileAuthInitFilter` for issuing the challenge nonce and generating the deep link with the authentication request, used to initiate the mobile authentication flow,
     -   `WebEidAjaxLoginProcessingFilter` and `WebEidLoginPageGeneratingFilter` for handling login requests.
--   `service`: Web eID signing service implementation that uses DigiDoc4j, and DigiDoc4j runtime configuration,
+-   `service`: Web eID signing service implementation that uses DigiDoc4j, and DigiDoc4j runtime configuration.
+    -   `SigningService`: prepares ASiC-E containers and finalizes signatures.
+    -   `MobileSigningService`: orchestrates the mobile signing flow (builds mobile signing requests/responses) and supports requesting the signing certificate in a separate step when enabled by configuration.
 -   `web`: Spring Web MVC controller for the welcome page and Spring Web REST controller that provides a digital signing endpoint.
 
 The `src/resources` directory contains the resources used by the application:
@@ -177,6 +180,16 @@ A common alternative to stateful authentication is stateless authentication with
 
 It is usually required to verify that the signing certificate subject matches the authentication certificate subject by assuring that both ID codes match. This check is implemented at the beginning of the `SigningService.prepareContainer()` method.
 
+### Requesting the signing certificate in a separate step
+
+In some deployments, the signing certificate is not reused from the authentication flow. Instead, it is retrieved directly from the user’s ID-card during the signing process itself.
+
+This approach is useful when the signing process is performed without a prior authentication step. For example, in a mobile flow, the user may start signing directly without authenticating beforehand. In such cases, the signing certificate must be requested separately from the user’s ID-card before the signature can be created.
+
+When this mode is enabled in the configuration, the backend issues a separate request for the signing certificate using the `MobileSigningService`. The service communicates with the client to obtain the certificate before the signing container is prepared, ensuring that the correct certificate chain is available for the signature.
+
+This behavior is controlled by the `request-signing-cert` flag in the `application.yaml` configuration files (`application-dev.yaml`, `application-prod.yaml`). When the flag is set to **false**, the application explicitly requests the signing certificate during the signing process, demonstrating the separate signing certificate retrieval flow. When set to **true**, the signing uses the signing certificate that was already obtained during authentication, and no additional request is made.
+
 ## HTTPS support
 
 There are two ways of adding HTTPS support to a Spring Boot application:
 
@@ -10,7 +10,7 @@
 	</parent>
 	<groupId>eu.webeid.example</groupId>
 	<artifactId>web-eid-springboot-example</artifactId>
-	<version>3.2.1-SNAPSHOT</version>
+	<version>4.0.0-SNAPSHOT</version>
 	<name>web-eid-springboot-example</name>
 	<description>Example Spring Boot application that demonstrates how to use Web eID for authentication and digital
 		signing
@@ -19,8 +19,8 @@
 	<properties>
 		<java.version>17</java.version>
 		<maven-surefire-plugin.version>3.5.3</maven-surefire-plugin.version>
-		<webeid.version>3.2.1-SNAPSHOT</webeid.version>
-		<digidoc4j.version>6.1.0</digidoc4j.version>
+		<webeid.version>4.0.0-SNAPSHOT</webeid.version>
+		<digidoc4j.version>6.0.1</digidoc4j.version>
 		<jmockit.version>1.44</jmockit.version> <!-- Keep version 1.44, otherwise mocking will fail. -->
 		<jib.version>3.5.1</jib.version>
 	</properties>
@@ -38,6 +38,10 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-thymeleaf</artifactId>
 		</dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-validation</artifactId>
+        </dependency>
 
 		<dependency>
 			<groupId>org.digidoc4j</groupId>
 
@@ -28,6 +28,7 @@
 import eu.webeid.example.security.WebEidMobileAuthInitFilter;
 import eu.webeid.example.security.ui.WebEidLoginPageGeneratingFilter;
 import eu.webeid.security.challenge.ChallengeNonceGenerator;
+import org.springframework.boot.context.properties.ConfigurationPropertiesScan;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.security.config.annotation.authentication.configuration.AuthenticationConfiguration;
@@ -39,9 +40,9 @@
 import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;
 import org.springframework.security.web.authentication.logout.HttpStatusReturningLogoutSuccessHandler;
 import org.thymeleaf.ITemplateEngine;
-import org.thymeleaf.web.servlet.JakartaServletWebApplication;
 
 @Configuration
+@ConfigurationPropertiesScan
 @EnableWebSecurity
 @EnableMethodSecurity(securedEnabled = true)
 public class ApplicationConfiguration {
@@ -53,7 +54,7 @@ public SecurityFilterChain filterChain(
         AuthenticationConfiguration authConfig,
         ChallengeNonceGenerator challengeNonceGenerator,
         ITemplateEngine templateEngine,
-        JakartaServletWebApplication webApp
+        WebEidMobileProperties webEidMobileProperties
     ) throws Exception {
         return http
             .authorizeHttpRequests(auth -> auth
@@ -62,9 +63,9 @@ public SecurityFilterChain filterChain(
                 .anyRequest().authenticated()
             )
             .authenticationProvider(webEidAuthenticationProvider)
-            .addFilterBefore(new WebEidMobileAuthInitFilter("/auth/mobile/init", "/auth/mobile/login", challengeNonceGenerator), UsernamePasswordAuthenticationFilter.class)
+            .addFilterBefore(new WebEidMobileAuthInitFilter("/auth/mobile/init", "/auth/mobile/login", challengeNonceGenerator, webEidMobileProperties), UsernamePasswordAuthenticationFilter.class)
             .addFilterBefore(new WebEidChallengeNonceFilter("/auth/challenge", challengeNonceGenerator), UsernamePasswordAuthenticationFilter.class)
-            .addFilterBefore(new WebEidLoginPageGeneratingFilter("/auth/mobile/login", "/auth/login", templateEngine, webApp), UsernamePasswordAuthenticationFilter.class)
+            .addFilterBefore(new WebEidLoginPageGeneratingFilter("/auth/mobile/login", "/auth/login", templateEngine), UsernamePasswordAuthenticationFilter.class)
             .addFilterBefore(new WebEidAjaxLoginProcessingFilter("/auth/login", authConfig.getAuthenticationManager()), UsernamePasswordAuthenticationFilter.class)
             .logout(l -> l.logoutSuccessHandler(new HttpStatusReturningLogoutSuccessHandler()))
             .headers(h -> h.frameOptions(HeadersConfigurer.FrameOptionsConfig::sameOrigin))
 
@@ -79,24 +79,19 @@ public ChallengeNonceGenerator generator(ChallengeNonceStore challengeNonceStore
     }
 
     @Bean
-    public AuthTokenValidator validator(YAMLConfig yamlConfig) {
+    public AuthTokenValidator validator(WebEidAuthTokenProperties authTokenProperties) {
         try {
             return new AuthTokenValidatorBuilder()
-                .withSiteOrigin(URI.create(yamlConfig.getLocalOrigin()))
+                .withSiteOrigin(URI.create(authTokenProperties.validation().localOrigin()))
                 .withTrustedCertificateAuthorities(loadTrustedCACertificatesFromCerFiles())
-                .withTrustedCertificateAuthorities(loadTrustedCACertificatesFromTrustStore(yamlConfig))
-                .withOcspRequestTimeout(yamlConfig.getOcspRequestTimeout())
+                .withTrustedCertificateAuthorities(loadTrustedCACertificatesFromTrustStore(authTokenProperties))
+                .withOcspRequestTimeout(authTokenProperties.validation().ocspRequestTimeout())
                 .build();
         } catch (JceException e) {
             throw new RuntimeException("Error building the Web eID auth token validator.", e);
         }
     }
 
-    @Bean
-    public YAMLConfig yamlConfig() {
-        return new YAMLConfig();
-    }
-
     private X509Certificate[] loadTrustedCACertificatesFromCerFiles() {
         List<X509Certificate> caCertificates = new ArrayList<>();
 
@@ -117,17 +112,22 @@ private X509Certificate[] loadTrustedCACertificatesFromCerFiles() {
 
         return caCertificates.toArray(new X509Certificate[0]);
     }
-
-    private X509Certificate[] loadTrustedCACertificatesFromTrustStore(YAMLConfig yamlConfig) {
+    private X509Certificate[] loadTrustedCACertificatesFromTrustStore(WebEidAuthTokenProperties authTokenProperties) {
         List<X509Certificate> caCertificates = new ArrayList<>();
 
         try (InputStream is = ValidationConfiguration.class.getResourceAsStream(CERTS_RESOURCE_PATH + activeProfile + "/" + TRUSTED_CERTIFICATES_JKS)) {
             if (is == null) {
                 LOG.info("Truststore file {} not found for {} profile", TRUSTED_CERTIFICATES_JKS, activeProfile);
                 return new X509Certificate[0];
             }
+
+            String trustStorePassword = authTokenProperties.validation().trustStorePassword();
+            if (trustStorePassword == null || trustStorePassword.isBlank()) {
+                throw new IllegalStateException("Truststore password must be configured because truststore exists for profile '" + activeProfile + "'.");
+            }
+
             KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType());
-            keystore.load(is, yamlConfig.getTrustStorePassword().toCharArray());
+            keystore.load(is, trustStorePassword.toCharArray());
             Enumeration<String> aliases = keystore.aliases();
             while (aliases.hasMoreElements()) {
                 String alias = aliases.nextElement();
@@ -140,7 +140,4 @@ private X509Certificate[] loadTrustedCACertificatesFromTrustStore(YAMLConfig yam
 
         return caCertificates.toArray(new X509Certificate[0]);
     }
-
-
-
 }
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2020-2025 Estonian Information System Authority
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package eu.webeid.example.config;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Pattern;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.boot.context.properties.bind.DefaultValue;
+import org.springframework.validation.annotation.Validated;
+
+import java.time.Duration;
+
+@Validated
+@ConfigurationProperties(prefix = "web-eid-auth-token")
+public record WebEidAuthTokenProperties(WebEidAuthTokenValidation validation) {
+
+    public record WebEidAuthTokenValidation(
+        @NotBlank
+        @Pattern(
+            regexp = "^https://[A-Za-z0-9.-]+(:\\d{1,5})?$",
+            message = "Origin URL must be in the form of 'https://' <hostname> [ ':' <port> ] and not end with a trailing slash"
+        )
+        String localOrigin,
+        String siteCertHash,
+        String trustStorePassword,
+        @DefaultValue("5s") Duration ocspRequestTimeout,
+        @NotNull Boolean useDigiDoc4jProdConfiguration) {
+    }
+}
@@ -22,16 +22,14 @@
 
 package eu.webeid.example.config;
 
-import jakarta.servlet.ServletContext;
-import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.Configuration;
-import org.thymeleaf.web.servlet.JakartaServletWebApplication;
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.Pattern;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.validation.annotation.Validated;
 
-@Configuration
-public class ThymeleafWebAppConfiguration {
-
-    @Bean
-    public JakartaServletWebApplication jakartaServletWebApplication(ServletContext servletContext) {
-        return JakartaServletWebApplication.buildApplication(servletContext);
-    }
+@Validated
+@ConfigurationProperties(prefix = "web-eid-mobile")
+public record WebEidMobileProperties(
+    @NotBlank @Pattern(regexp = "^.*(?:[^/]|://)$", message = "Base URI must not have a trailing slash") String baseRequestUri,
+    boolean requestSigningCert) {
 }