UFAL/Shibboleth - show error in the UI when shibboleth authentication is failed (#810)

* The user is not signed in without using link with the verification token from the email/

* Send a redirect to UI with specific parameter that the Shibboleth authorization wasn't successful

Author: milanmajchrak

dspace-api/src/main/java/org/dspace/core/Utils.java

@@ -506,4 +506,21 @@ public static String interpolateConfigsInString(String string) {
         ConfigurationService config = DSpaceServicesFactory.getInstance().getConfigurationService();
         return StringSubstitutor.replace(string, config.getProperties());
     }
+
+    /**
+     * Replace the last occurrence of a substring within a string.
+     *
+     * @param input The input string
+     * @param toReplace The substring to replace
+     * @param replacement The replacement substring
+     * @return Replaced input string or the original input string if the substring to replace is not found
+     */
+    public static String replaceLast(String input, String toReplace, String replacement) {
+        int lastIndex = input.lastIndexOf(toReplace);
+        if (lastIndex == -1) {
+            return input; // No replacement if not found
+        }
+
+        return input.substring(0, lastIndex) + replacement + input.substring(lastIndex + toReplace.length());
+    }
 }

dspace-api/src/test/java/org/dspace/core/UtilsTest.java

@@ -132,4 +132,24 @@ public void testInterpolateConfigsInString() {
         // remove the config we added
         configurationService.setProperty(configName, null);
     }
+
+    // Replace the last occurrence of a substring
+    @Test
+    public void testReplaceLast_SingleOccurrence() {
+        String input = "/login/";
+        String result = Utils.replaceLast(input, "/", "replacement");
+
+        // Expected output: "/loginreplacement"
+        assertEquals("/loginreplacement", result);
+    }
+
+    // No replacement when the substring is not found
+    @Test
+    public void testReplaceLast_NoMatch() {
+        String input = "/login";
+        String result = Utils.replaceLast(input, "/", "replacement");
+
+        // Expected output: "/login"
+        assertEquals("replacementlogin", result);
+    }
 }

dspace-server-webapp/src/main/java/org/dspace/app/rest/security/clarin/ClarinShibbolethLoginFilter.java

@@ -261,6 +261,7 @@ protected void unsuccessfulAuthentication(HttpServletRequest request,
         String missingHeadersUrl = "missing-headers";
         String userWithoutEmailUrl = "auth-failed";
         String duplicateUser = "duplicate-user";
+        String cannotAuthenticate = "shibboleth-authentication-failed";
 
         // Compose the redirect URL
         if (this.isMissingHeadersFromIdp) {
@@ -270,6 +271,11 @@ protected void unsuccessfulAuthentication(HttpServletRequest request,
         } else if (StringUtils.isNotEmpty(this.netId)) {
             // netId is set if the user doesn't have the email
             redirectUrl += userWithoutEmailUrl + "?netid=" + this.netId;
+        } else {
+            // Remove the last slash from the URL `login/`
+            String redirectUrlWithoutSlash = redirectUrl.endsWith("/") ?
+                    Utils.replaceLast(redirectUrl, "/", "") : redirectUrl;
+            redirectUrl = redirectUrlWithoutSlash + "?error=" + cannotAuthenticate;
         }
 
         response.sendRedirect(redirectUrl);

dspace-server-webapp/src/test/java/org/dspace/app/rest/security/ClarinShibbolethLoginFilterIT.java

@@ -658,6 +658,18 @@ public void shouldNotAuthenticateOnSecondAttemptWithoutVerificationTokenInReques
                         Util.formatNetId(netId, idp)));
     }
 
+    @Test
+    public void shouldSendShibbolethAuthError() throws Exception {
+        String idp = "Test Idp";
+
+        // Try to authenticate but the Shibboleth doesn't send the email or netid in the header,
+        // so the user won't be registered but the user will be redirected to the login page with the error message.
+        getClient().perform(get("/api/authn/shibboleth")
+                        .header("Shib-Identity-Provider", idp))
+                .andExpect(status().isFound())
+                .andExpect(redirectedUrl("http://localhost:4000/login?error=shibboleth-authentication-failed"));
+    }
+
     private EPerson checkUserWasCreated(String netIdValue, String idpValue, String email, String name)
             throws SQLException {
         // Check if was created a user with such email and netid.