From 9aa92ee9a213ebd78e12a22cf93b60ce9eb7b3f7 Mon Sep 17 00:00:00 2001
From: Ricardo Martin <rmartinc@redhat.com>
Date: Thu, 18 Apr 2024 14:02:24 +0000
Subject: [PATCH] Perform exact string match if redirect URI contains userinfo, encoded slashes or parent access (#131) (#28872)
---
src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java | 139 ++++++++++++++++++++++++++++-----------------
1 files changed, 86 insertions(+), 53 deletions(-)
diff --git a/src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java b/src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java
index d6e739d..de8fd84 100644
--- a/src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java
+++ b/src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java
@@ -24,13 +24,15 @@
import org.keycloak.models.KeycloakSession;
import org.keycloak.models.KeycloakUriInfo;
import org.keycloak.models.RealmModel;
+import org.keycloak.protocol.oidc.OIDCLoginProtocol;
import org.keycloak.services.Urls;
import org.keycloak.services.util.ResolveRelative;
import java.net.URI;
import java.util.Collection;
-import java.util.HashSet;
import java.util.Set;
+import java.util.TreeSet;
+import java.util.regex.Pattern;
import java.util.stream.Collectors;
/**
@@ -40,6 +42,12 @@
private static final Logger logger = Logger.getLogger(RedirectUtils.class);
+ /**
+ * This method is deprecated for performance and security reasons and it is available just for the
+ * backwards compatibility. It is recommended to use some other methods of this class where the client is given as an argument
+ * to the method, so we know the client, which redirect-uri we are trying to resolve.
+ */
+ @Deprecated
public static String verifyRealmRedirectUri(KeycloakSession session, String redirectUri) {
Set<String> validRedirects = getValidateRedirectUris(session);
return verifyRedirectUri(session, null, redirectUri, validRedirects, true);
@@ -57,44 +65,32 @@
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;
}
+ @Deprecated
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());
+ RealmModel realm = session.getContext().getRealm();
+ return session.clients().getAllRedirectUrisOfEnabledClients(realm).entrySet().stream()
+ .filter(me -> me.getKey().isEnabled() && OIDCLoginProtocol.LOGIN_PROTOCOL.equals(me.getKey().getProtocol()) && !me.getKey().isBearerOnly() && (me.getKey().isStandardFlowEnabled() || me.getKey().isImplicitFlowEnabled()))
+ .map(me -> resolveValidRedirects(session, me.getKey().getRootUrl(), me.getValue()))
+ .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 +104,21 @@
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 +131,27 @@
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 +161,28 @@
}
}
- 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 +199,31 @@
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 +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));
- }
}
--
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