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

@@ -150,12 +150,16 @@
    }

    // 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 unsafe pattern in path
        // wildcars are only allowed if no user-info and no unparsed authority and no unsafe pattern in path
        return redirectUri.getRawUserInfo() == null
                && !(redirectUri.getRawAuthority() != null && redirectUri.getRawUserInfo() == null && redirectUri.getHost() == null && redirectUri.getPort() == -1)
                && (redirectUri.getRawPath() == null || !UNSAFE_PATH_PATTERN.matcher(redirectUri.getRawPath()).find());
    }

@@ -180,22 +184,57 @@
            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('#');
            } else {
                String validRedirectWildcard = allowWildcards ? checkValidRedirectWildcard(validRedirect) : null;
                if (validRedirectWildcard != null) {
                    // 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 = validRedirectWildcard.length() - 1;
                    validRedirectWildcard = validRedirectWildcard.substring(0, length);
                    if (r.startsWith(validRedirectWildcard)) {
                        return validRedirectWildcard;
                    }
                    // strip off trailing '/'
                    if (length - 1 > 0 && validRedirectWildcard.charAt(length - 1) == '/') {
                        length--;
                    }
                    validRedirectWildcard = validRedirectWildcard.substring(0, length);
                    if (validRedirectWildcard.equals(r)) {
                        return validRedirectWildcard;
                    }
                } else if (validRedirect.equals(redirect)) {
                    return validRedirect;
                }
                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 validRedirect;
                // strip off trailing '/'
                if (length - 1 > 0 && validRedirect.charAt(length - 1) == '/') length--;
                validRedirect = validRedirect.substring(0, length);
                if (validRedirect.equals(r)) return validRedirect;
            } else if (validRedirect.equals(redirect)) return validRedirect;
            }
        }
        return null;
    }

    private static String checkValidRedirectWildcard(String validRedirect) {
        if (!validRedirect.endsWith("*") || validRedirect.contains("?") || validRedirect.contains("#")) {
            return null; // no wildcard as before
        }
        KeycloakUriBuilder uriBuilder = KeycloakUriBuilder.fromUri(validRedirect, false);
        if (uriBuilder.getPath() != null) {
            return validRedirect; // wildcard valid on path
        }
        if (uriBuilder.getAuthority() != null) {
            if (uriBuilder.getAuthority().equals("*") || uriBuilder.getAuthority().endsWith(":*")) {
                return validRedirect; // on authority just full wildcard or on port
            } else {
                // treat the wildcard after the authority
                validRedirect = validRedirect.substring(0, validRedirect.length() - 1);
                validRedirect = validRedirect + "/*";
                return validRedirect;
            }
        }
        if (uriBuilder.getSsp() != null) {
            return validRedirect; // wildcard valid on SSP
        }
        return null;
    }