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

@@ -18,8 +18,6 @@
package org.keycloak.protocol.oidc.utils;

import org.jboss.logging.Logger;
import org.keycloak.common.util.Encode;
import org.keycloak.common.util.KeycloakUriBuilder;
import org.keycloak.common.util.UriUtils;
import org.keycloak.models.ClientModel;
import org.keycloak.models.Constants;
@@ -34,6 +32,7 @@
import java.util.Collection;
import java.util.Set;
import java.util.TreeSet;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

/**
@@ -72,10 +71,8 @@
            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;
    }
@@ -107,16 +104,19 @@
            logger.debug("No Redirect URIs supplied");
            redirectUri = null;
        } else {
            // Make the validations against fully decoded and normalized redirect-url. This also allows wildcards (case when client configured "Valid redirect-urls" contain wildcards)
            String decodedRedirectUri = decodeRedirectUri(redirectUri);
            URI decodedRedirect = toUri(decodedRedirectUri);
            decodedRedirectUri = getNormalizedRedirectUri(decodedRedirect);
            if (decodedRedirectUri == null) return null;
            URI originalRedirect = toUri(redirectUri);
            if (originalRedirect == null) {
                // invalid URI passed as redirectUri
                return null;
            }

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

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

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

            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());
@@ -131,23 +131,18 @@

                r = sb.toString();

                valid = matchesRedirects(resolveValidRedirects, r, true);
                valid = matchesRedirects(resolveValidRedirects, r, allowWildcards);
            }

            // Return the original redirectUri, which can be partially encoded - for example http://localhost:8280/foo/bar%20bar%2092%2F72/3 . Just make sure it is normalized
            URI redirect = toUri(redirectUri);
            redirectUri = getNormalizedRedirectUri(redirect);

            // We try to check validity also for original (encoded) redirectUrl, but just in case it exactly matches some "Valid Redirect URL" specified for client (not wildcards allowed)
            if (valid == null) {
                valid = matchesRedirects(resolveValidRedirects, redirectUri, false);
            }

            if (valid != null && 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);
            }

            String scheme = decodedRedirect.getScheme();
            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)) {
@@ -169,69 +164,25 @@
    private static URI toUri(String redirectUri) {
        URI uri = null;
        if (redirectUri != null) {
        try {
            try {
                uri = URI.create(redirectUri);
            } catch (IllegalArgumentException cause) {
                logger.debug("Invalid redirect uri", cause);
                logger.debugf(cause, "Invalid redirect uri %s", redirectUri);
            } catch (Exception cause) {
                logger.debug("Unexpected error when parsing redirect uri", cause);
                logger.debugf(cause, "Unexpected error when parsing redirect uri %s", redirectUri);
            }
        }
        return uri;
    }

    private static String getNormalizedRedirectUri(URI uri) {
        String redirectUri = null;
        if (uri != null) {
            redirectUri = uri.normalize().toString();
            redirectUri = lowerCaseHostname(redirectUri);
        }
        return redirectUri;
    }
    // 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}$");

    // Decode redirectUri. We don't decode query and fragment as those can be encoded in the original URL.
    // URL can be decoded multiple times (in case it was encoded multiple times, or some of it's parts were encoded multiple times)
    private static String decodeRedirectUri(String redirectUri) {
        if (redirectUri == null) return null;
        int MAX_DECODING_COUNT = 5; // Max count of attempts for decoding URL (in case it was encoded multiple times)

        try {
            KeycloakUriBuilder uriBuilder = KeycloakUriBuilder.fromUri(redirectUri).preserveDefaultPort();
            String origQuery = uriBuilder.getQuery();
            String origFragment = uriBuilder.getFragment();
            String encodedRedirectUri = uriBuilder
                    .replaceQuery(null)
                    .fragment(null)
                    .buildAsString();
            String decodedRedirectUri = null;

            for (int i = 0; i < MAX_DECODING_COUNT; i++) {
                decodedRedirectUri = Encode.decode(encodedRedirectUri);
                if (decodedRedirectUri.equals(encodedRedirectUri)) {
                    // URL is decoded. We can return it (after attach original query and fragment)
                    return KeycloakUriBuilder.fromUri(decodedRedirectUri).preserveDefaultPort()
                            .replaceQuery(origQuery)
                            .fragment(origFragment)
                            .buildAsString();
                } else {
                    // Next attempt
                    encodedRedirectUri = decodedRedirectUri;
                }
            }
        } catch (IllegalArgumentException iae) {
            logger.debugf("Illegal redirect URI used: %s, Details: %s", redirectUri, iae.getMessage());
        }
        logger.debugf("Was not able to decode redirect URI: %s", redirectUri);
        return null;
    }

    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 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) {
@@ -252,9 +203,16 @@
    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("?") && allowWildcards) {
                // 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);
@@ -284,13 +242,4 @@
        }
        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));
    }
}