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

@@ -29,9 +29,9 @@

import java.net.URI;
import java.util.Collection;
import java.util.HashSet;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.TreeSet;
import java.util.regex.Pattern;

/**
 * @author <a href="mailto:sthorger@redhat.com">Stian Thorgersen</a>
@@ -40,11 +40,6 @@

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

    public static String verifyRealmRedirectUri(KeycloakSession session, String redirectUri) {
        Set<String> validRedirects = getValidateRedirectUris(session);
        return verifyRedirectUri(session, null, redirectUri, validRedirects, true);
    }

    public static String verifyRedirectUri(KeycloakSession session, String redirectUri, ClientModel client) {
        return verifyRedirectUri(session, redirectUri, client, true);
    }
@@ -57,44 +52,22 @@

    public static Set<String> resolveValidRedirects(KeycloakSession session, String rootUrl, Set<String> validRedirects) {
        // If the valid redirect URI is relative (no scheme, host, port) then use the request's scheme, host, and port
        Set<String> resolveValidRedirects = new HashSet<>();
        // the set is ordered by length to get the longest match first
        Set<String> resolveValidRedirects = new TreeSet<>((String s1, String s2) -> s1.length() == s2.length()? s1.compareTo(s2) : s1.length() < s2.length()? 1 : -1);
        for (String validRedirect : validRedirects) {
            if (validRedirect.startsWith("/")) {
                validRedirect = relativeToAbsoluteURI(session, rootUrl, validRedirect);
                logger.debugv("replacing relative valid redirect with: {0}", validRedirect);
                resolveValidRedirects.add(validRedirect);
            } else {
                resolveValidRedirects.add(validRedirect);
            }
            resolveValidRedirects.add(validRedirect);
        }
        return resolveValidRedirects;
    }

    private static Set<String> getValidateRedirectUris(KeycloakSession session) {
        return session.getContext().getRealm().getClientsStream()
                .filter(ClientModel::isEnabled)
                .map(c -> resolveValidRedirects(session, c.getRootUrl(), c.getRedirectUris()))
                .flatMap(Collection::stream)
                .collect(Collectors.toSet());
    }

    private static String verifyRedirectUri(KeycloakSession session, String rootUrl, String redirectUri, Set<String> validRedirects, boolean requireRedirectUri) {
    public static String verifyRedirectUri(KeycloakSession session, String rootUrl, String redirectUri, Set<String> validRedirects, boolean requireRedirectUri) {
        KeycloakUriInfo uriInfo = session.getContext().getUri();
        RealmModel realm = session.getContext().getRealm();

        if (redirectUri != null) {
            try {
                URI uri = URI.create(redirectUri);
                redirectUri = uri.normalize().toString();
            } catch (IllegalArgumentException cause) {
                logger.debug("Invalid redirect uri", cause);
                return null;
            } catch (Exception cause) {
                logger.debug("Unexpected error when parsing redirect uri", cause);
                return null;
            }
        }

        if (redirectUri == null) {
            if (!requireRedirectUri) {
                redirectUri = getSingleValidRedirectUri(validRedirects);
@@ -108,14 +81,21 @@
            logger.debug("No Redirect URIs supplied");
            redirectUri = null;
        } else {
            redirectUri = lowerCaseHostname(redirectUri);
            URI originalRedirect = toUri(redirectUri);
            if (originalRedirect == null) {
                // invalid URI passed as redirectUri
                return null;
            }

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

            String r = redirectUri;
            Set<String> resolveValidRedirects = resolveValidRedirects(session, rootUrl, validRedirects);

            boolean valid = matchesRedirects(resolveValidRedirects, r);
            String valid = matchesRedirects(resolveValidRedirects, r, allowWildcards);

            if (!valid && r.startsWith(Constants.INSTALLED_APP_URL) && r.indexOf(':', Constants.INSTALLED_APP_URL.length()) >= 0) {
            if (valid == null && (r.startsWith(Constants.INSTALLED_APP_URL) || r.startsWith(Constants.INSTALLED_APP_LOOPBACK)) && r.indexOf(':', Constants.INSTALLED_APP_URL.length()) >= 0) {
                int i = r.indexOf(':', Constants.INSTALLED_APP_URL.length());

                StringBuilder sb = new StringBuilder();
@@ -128,12 +108,27 @@

                r = sb.toString();

                valid = matchesRedirects(resolveValidRedirects, r);
                valid = matchesRedirects(resolveValidRedirects, r, allowWildcards);
            }
            if (valid && redirectUri.startsWith("/")) {

            if (valid != null && !originalRedirect.isAbsolute()) {
                // return absolute if the original URI is relative
                if (!redirectUri.startsWith("/")) {
                    redirectUri = "/" + redirectUri;
                }
                redirectUri = relativeToAbsoluteURI(session, rootUrl, redirectUri);
            }
            redirectUri = valid ? redirectUri : null;

            String scheme = originalRedirect.getScheme();
            if (valid != null && scheme != null) {
                // check the scheme is valid, it should be http(s) or explicitly allowed by the validation
                if (!valid.startsWith(scheme + ":") && !"http".equalsIgnoreCase(scheme) && !"https".equalsIgnoreCase(scheme)) {
                    logger.debugf("Invalid URI because scheme is not allowed: %s", redirectUri);
                    valid = null;
                }
            }

            redirectUri = valid != null ? redirectUri : null;
        }

        if (Constants.INSTALLED_APP_URN.equals(redirectUri)) {
@@ -143,13 +138,28 @@
        }
    }

    private static String lowerCaseHostname(String redirectUri) {
        int n = redirectUri.indexOf('/', 7);
        if (n == -1) {
            return redirectUri.toLowerCase();
        } else {
            return redirectUri.substring(0, n).toLowerCase() + redirectUri.substring(n);
    private static URI toUri(String redirectUri) {
        URI uri = null;
        if (redirectUri != null) {
            try {
                uri = URI.create(redirectUri);
            } catch (IllegalArgumentException cause) {
                logger.debugf(cause, "Invalid redirect uri %s", redirectUri);
            } catch (Exception cause) {
                logger.debugf(cause, "Unexpected error when parsing redirect uri %s", redirectUri);
            }
        }
        return uri;
    }

    // any access to parent folder /../ is unsafe with or without encoding
    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}$");

    private static boolean areWildcardsAllowed(URI redirectUri) {
        // wildcars are only allowed if no user-info and no unsafe pattern in path
        return redirectUri.getRawUserInfo() == null
                && (redirectUri.getRawPath() == null || !UNSAFE_PATH_PATTERN.matcher(redirectUri.getRawPath()).find());
    }

    private static String relativeToAbsoluteURI(KeycloakSession session, String rootUrl, String relative) {
@@ -166,22 +176,31 @@
        return sb.toString();
    }

    private static boolean matchesRedirects(Set<String> validRedirects, String redirect) {
    // return the String that matched the redirect or null if not matched
    private static String matchesRedirects(Set<String> validRedirects, String redirect, boolean allowWildcards) {
        logger.tracef("matchesRedirects: redirect URL to check: %s, allow wildcards: %b, Configured valid redirect URLs: %s", redirect, allowWildcards, validRedirects);
        for (String validRedirect : validRedirects) {
            if (validRedirect.endsWith("*") && !validRedirect.contains("?")) {
                // strip off the query component - we don't check them when wildcards are effective
                String r = redirect.contains("?") ? redirect.substring(0, redirect.indexOf("?")) : redirect;
            if ("*".equals(validRedirect)) {
                // the valid redirect * is a full wildcard for http(s) even if the redirect URI does not allow wildcards
                return validRedirect;
            } else if (validRedirect.endsWith("*") && !validRedirect.contains("?") && allowWildcards) {
                // strip off the query or fragment components - we don't check them when wildcards are effective
                int idx = redirect.indexOf('?');
                if (idx == -1) {
                    idx = redirect.indexOf('#');
                }
                String r = idx == -1 ? redirect : redirect.substring(0, idx);
                // strip off *
                int length = validRedirect.length() - 1;
                validRedirect = validRedirect.substring(0, length);
                if (r.startsWith(validRedirect)) return true;
                if (r.startsWith(validRedirect)) return validRedirect;
                // strip off trailing '/'
                if (length - 1 > 0 && validRedirect.charAt(length - 1) == '/') length--;
                validRedirect = validRedirect.substring(0, length);
                if (validRedirect.equals(r)) return true;
            } else if (validRedirect.equals(redirect)) return true;
                if (validRedirect.equals(r)) return validRedirect;
            } else if (validRedirect.equals(redirect)) return validRedirect;
        }
        return false;
        return null;
    }

    private static String getSingleValidRedirectUri(Collection<String> validRedirects) {
@@ -200,13 +219,4 @@
        }
        return redirectUri;
    }

    private static String getFirstValidRedirectUri(Collection<String> validRedirects) {
        final String redirectUri = validRedirects.stream().findFirst().orElse(null);
        return (redirectUri != null) ? validateRedirectUriWildcard(redirectUri) : null;
    }

    public static String getFirstValidRedirectUri(KeycloakSession session, String rootUrl, Set<String> validRedirects) {
        return getFirstValidRedirectUri(resolveValidRedirects(session, rootUrl, validRedirects));
    }
}