Update mock dates in example app tests

The test user certificate expired on 2026-07-09, which made auth token
validation fail with CertificateExpiredException. Mock the validation
clock to a date within the certificate validity period, like commit
8ab06e0 did for the library tests.

Author: aarmam

example/src/test/java/eu/webeid/example/WebApplicationTest.java

@@ -103,6 +103,7 @@ public void validateOcspResponse(XadesSignature xadesSignature) {
         session.setAttribute("challenge-nonce", new ChallengeNonce(ObjectMother.VALID_CHALLENGE_NONCE, DateAndTime.utcNow().plusMinutes(1)));
 
         Dates.setMockedSignatureDate(Dates.getSigningDateTime());
+        Dates.setMockedAuthTokenValidationDate(Dates.getAuthTokenValidationDateTime());
 
         // Act and assert
         mvcBuilder.build().perform(get("/auth/challenge"));

example/src/test/java/eu/webeid/example/testutil/Dates.java

@@ -23,6 +23,7 @@
 package eu.webeid.example.testutil;
 
 import eu.europa.esig.dss.model.BLevelParameters;
+import eu.webeid.security.util.DateAndTime;
 import mockit.Mock;
 import mockit.MockUp;
 
@@ -37,6 +38,12 @@ public static ZonedDateTime getSigningDateTime() {
                 ZoneId.of("Europe/Tallinn"));
     }
 
+    public static ZonedDateTime getAuthTokenValidationDateTime() {
+        // Ensure that the certificates do not expire.
+        return ZonedDateTime.of(2021, 7, 23, 0, 0, 0, 0,
+                ZoneId.of("UTC"));
+    }
+
     public static void setMockedSignatureDate(ZonedDateTime mockedDateTime) {
         new MockUp<BLevelParameters>() {
             @Mock
@@ -45,4 +52,13 @@ public Date getSigningDate() {
             }
         };
     }
+
+    public static void setMockedAuthTokenValidationDate(ZonedDateTime mockedDateTime) {
+        new MockUp<DateAndTime.DefaultClock>() {
+            @Mock
+            public Date now() {
+                return Date.from(mockedDateTime.toInstant());
+            }
+        };
+    }
 }