src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java

@@ -15,25 +15,26 @@
 * limitations under the License.
 */

package org.keycloak.protocol.oidc.utils;
package org.keycloak.protocol.cas.utils;

import java.net.URI;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Set;
import java.util.TreeSet;
import java.util.regex.Pattern;

import org.keycloak.common.util.KeycloakUriBuilder;
import org.keycloak.common.util.MultivaluedHashMap;
import org.keycloak.common.util.UriUtils;
import org.keycloak.models.ClientModel;
import org.keycloak.models.Constants;
import org.keycloak.models.KeycloakSession;
import org.keycloak.models.KeycloakUriInfo;
import org.keycloak.models.RealmModel;
import org.keycloak.protocol.cas.CASLoginProtocol;
import org.keycloak.services.Urls;
import org.keycloak.services.util.ResolveRelative;

@@ -46,6 +47,11 @@

    public static final Set<String> LOOPBACK_INTERFACES = new HashSet<>(Arrays.asList("localhost", "127.0.0.1", "[::1]"));

    private static final Set<String> FORBIDDEN_OIDC_PARAMS = Set.of(
            CASLoginProtocol.SAMLART_RESPONSE_PARAM.toLowerCase(Locale.ROOT),
            CASLoginProtocol.TICKET_RESPONSE_PARAM.toLowerCase(Locale.ROOT)
    );

    private static final Logger logger = Logger.getLogger(RedirectUtils.class);

    public static String verifyRedirectUri(KeycloakSession session, String redirectUri, ClientModel client) {
@@ -95,6 +101,11 @@
                return null;
            }

            // Check for HTTP Parameter Pollution - forbidden OIDC response parameters in redirect URI
            if (containsForbiddenOidcParameters(originalRedirect)){
                return null;
            }

            // check if the passed URI allows wildcards
            boolean allowWildcards = areWildcardsAllowed(originalRedirect);

@@ -135,6 +146,24 @@
        }
    }

    private static boolean containsForbiddenOidcParameters(URI originalRedirect) {
        String query = originalRedirect.getRawQuery();
        if (query != null && !query.isEmpty()) {
            MultivaluedHashMap<String, String> params =UriUtils.decodeQueryString(query);
            for (String paramName : params.keySet()) {
                if (FORBIDDEN_OIDC_PARAMS.contains(paramName.toLowerCase(Locale.ROOT))) {
                    logger.warnf("Redirect URI rejected: contains forbidden OIDC parameter '%s' in query string: scheme=%s, host=%s, path=%s",
                            paramName,
                            originalRedirect.getScheme(),
                            originalRedirect.getHost(),
                            originalRedirect.getPath());
                    return true;
                }
            }
        }
        return false;
    }

    private static URI toUri(String redirectUri) {
        URI uri = null;
        if (redirectUri != null) {
@@ -150,8 +179,11 @@
    }

    // any access to parent folder /../ is unsafe with or without encoding
    //   <sep>             = / | %2F | %5C | \
    //   <dots>            = "..", including %2E and %252E (double-encoded) variants
    //   <terminator>      = / | %2F | %5C | \ | ; | %3B | %09 | %0A | %0D | %00 | end-of-input
    private final static Pattern UNSAFE_PATH_PATTERN = Pattern.compile(
            "(/|%2[fF]|%5[cC]|\\\\)(%2[eE]|\\.){2}(/|%2[fF]|%5[cC]|\\\\|;)|(/|%2[fF]|%5[cC]|\\\\)(%2[eE]|\\.){2}$");
            "(/|%2[fF]|%5[cC]|\\\\)(%2[eE]|%252[eE]|\\.){2}(/|%2[fF]|%5[cC]|\\\\|;|%3[bB]|%09|%0[aAdD]|%00|$)");

    private static boolean areWildcardsAllowed(URI redirectUri) {
        // wildcars are only allowed if no user-info and no unparsed authority and no unsafe pattern in path
@@ -252,29 +284,4 @@
        }
        return redirectUri;
    }

    public static Set<String> resolveUrlsWithRedirects(KeycloakSession session, List<String> origUrls,
                                                       String rootUrl, List<String> redirectUris, boolean returnAsOrigins) {

        Set<String> refactoredUrls = (origUrls != null) ? new HashSet<>(origUrls) : new HashSet<>();
        if (refactoredUrls.contains(Constants.INCLUDE_REDIRECTS)) {
            refactoredUrls.remove(Constants.INCLUDE_REDIRECTS);

            Set<String> redirectsToProcess = (redirectUris != null) ? new HashSet<>(redirectUris) : Collections.emptySet();
            for (String redirectUri : resolveValidRedirects(session, rootUrl, redirectsToProcess)) {
                if (isValidScheme(redirectUri)) {
                    if (returnAsOrigins) {
                        refactoredUrls.add(UriUtils.getOrigin(redirectUri));
                    } else {
                        refactoredUrls.add(redirectUri);
                    }
                }
            }
        }
        return refactoredUrls;
    }

    private static boolean isValidScheme(String url) {
        return url != null && (url.startsWith("http://") || url.startsWith("https://"));
    }
}