From b3661a4c34bdc22ac7c25ebb0ae6584577ced091 Mon Sep 17 00:00:00 2001
From: Ricardo Martin <rmartinc@redhat.com>
Date: Wed, 28 Jun 2023 20:52:48 +0000
Subject: [PATCH] Check the redirect URI is http(s) when used for a form Post (#22)
---
src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java | 155 +++++++++++++++++++++++++++++++++++++++------------
1 files changed, 119 insertions(+), 36 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 dd8cebb..447685e 100644
--- a/src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java
+++ b/src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java
@@ -18,19 +18,23 @@
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;
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.stream.Collectors;
/**
* @author <a href="mailto:sthorger@redhat.com">Stian Thorgersen</a>
@@ -39,6 +43,12 @@
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);
@@ -56,7 +66,8 @@
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);
@@ -69,33 +80,20 @@
return resolveValidRedirects;
}
+ @Deprecated
private static Set<String> getValidateRedirectUris(KeycloakSession session) {
- Set<String> redirects = new HashSet<>();
- for (ClientModel client : session.getContext().getRealm().getClients()) {
- if (client.isEnabled()) {
- redirects.addAll(resolveValidRedirects(session, client.getRootUrl(), client.getRedirectUris()));
- }
- }
- return redirects;
+ 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);
@@ -109,14 +107,18 @@
logger.debug("No Redirect URIs supplied");
redirectUri = null;
} else {
- redirectUri = lowerCaseHostname(redirectUri);
+ // 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;
- String r = redirectUri;
+ String r = decodedRedirectUri;
Set<String> resolveValidRedirects = resolveValidRedirects(session, rootUrl, validRedirects);
- boolean valid = matchesRedirects(resolveValidRedirects, r);
+ String valid = matchesRedirects(resolveValidRedirects, r, true);
- 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();
@@ -129,12 +131,32 @@
r = sb.toString();
- valid = matchesRedirects(resolveValidRedirects, r);
+ valid = matchesRedirects(resolveValidRedirects, r, true);
}
- if (valid && redirectUri.startsWith("/")) {
+
+ // 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("/")) {
redirectUri = relativeToAbsoluteURI(session, rootUrl, redirectUri);
}
- redirectUri = valid ? redirectUri : null;
+
+ String scheme = decodedRedirect.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)) {
@@ -144,6 +166,65 @@
}
}
+ private static URI toUri(String redirectUri) {
+ URI uri = null;
+ if (redirectUri != null) {
+ try {
+ uri = URI.create(redirectUri);
+ } catch (IllegalArgumentException cause) {
+ logger.debug("Invalid redirect uri", cause);
+ } catch (Exception cause) {
+ logger.debug("Unexpected error when parsing redirect uri", cause);
+ }
+ }
+ return uri;
+ }
+
+ private static String getNormalizedRedirectUri(URI uri) {
+ String redirectUri = null;
+ if (uri != null) {
+ redirectUri = uri.normalize().toString();
+ redirectUri = lowerCaseHostname(redirectUri);
+ }
+ return redirectUri;
+ }
+
+ // 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) {
@@ -167,22 +248,24 @@
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("?")) {
+ 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;
// 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) {
--
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