From 760bd7b814836fca58922151abe67207cc0db1a2 Mon Sep 17 00:00:00 2001
From: Ricardo Martin <rmartinc@redhat.com>
Date: Tue, 09 Jan 2024 07:20:14 +0000
Subject: [PATCH] Escape action in the form_post.jwt and only decode path in RedirectUtils (#93) (#25995)
---
src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java | 159 +++++++++++++++++++++++++++++++++--------------------
1 files changed, 99 insertions(+), 60 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 9cb314b..1cae012 100644
--- a/src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java
+++ b/src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java
@@ -32,8 +32,8 @@
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;
/**
@@ -66,15 +66,14 @@
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;
}
@@ -93,20 +92,6 @@
KeycloakUriInfo uriInfo = session.getContext().getUri();
RealmModel realm = session.getContext().getRealm();
- redirectUri = decodeRedirectUri(redirectUri);
- 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);
@@ -120,14 +105,24 @@
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;
+ }
- String r = 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 = 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.startsWith(Constants.INSTALLED_APP_LOOPBACK)) && 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();
@@ -140,12 +135,35 @@
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
+ redirectUri = getNormalizedRedirectUri(originalRedirect);
+
+ // 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 && !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 = 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)) {
@@ -155,33 +173,50 @@
}
}
- // Decode redirectUri. We don't decode query and fragment as those can be encoded in the original URL.
+ 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();
+ }
+ return redirectUri;
+ }
+
+ // Decode redirectUri. Only path is decoded as other elements can be encoded in the original URL or cannot be encoded at all.
// 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);
- String origQuery = uriBuilder.getQuery();
- String origFragment = uriBuilder.getFragment();
- String encodedRedirectUri = uriBuilder
- .replaceQuery(null)
- .fragment(null)
- .buildAsString();
- String decodedRedirectUri = null;
+ KeycloakUriBuilder uriBuilder = KeycloakUriBuilder.fromUri(redirectUri, false).preserveDefaultPort();
+ if (uriBuilder.getPath() == null) {
+ return redirectUri;
+ }
+ String encodedPath = uriBuilder.getPath();
+ String decodedPath;
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)
- .replaceQuery(origQuery)
- .fragment(origFragment)
- .buildAsString();
+ decodedPath = Encode.decode(encodedPath);
+ if (decodedPath.equals(encodedPath)) {
+ // URL path is decoded. We can return it in the original redirect URI
+ return uriBuilder.replacePath(decodedPath, false).buildAsString();
} else {
// Next attempt
- encodedRedirectUri = decodedRedirectUri;
+ encodedPath = decodedPath;
}
}
} catch (IllegalArgumentException iae) {
@@ -191,15 +226,6 @@
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 String relativeToAbsoluteURI(KeycloakSession session, String rootUrl, String relative) {
if (rootUrl != null) {
rootUrl = ResolveRelative.resolveRootUrl(session, rootUrl);
@@ -214,22 +240,35 @@
return sb.toString();
}
- private static boolean matchesRedirects(Set<String> validRedirects, String redirect) {
+ // removes the queryString, fragment and userInfo from the redirect
+ // to avoid comparing this when wildcards are used
+ private static String stripOffRedirectForWildcard(String redirect) {
+ return KeycloakUriBuilder.fromUri(redirect, false)
+ .preserveDefaultPort()
+ .userInfo(null)
+ .replaceQuery(null)
+ .fragment(null)
+ .buildAsString();
+ }
+
+ // 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 (validRedirect.endsWith("*") && !validRedirect.contains("?") && allowWildcards) {
+ // strip off the userInfo, query or fragment components - we don't check them when wildcards are effective
+ String r = stripOffRedirectForWildcard(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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