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 | 60 ++++++++++++++++++++++++++++++++++++++++--------------------
1 files changed, 40 insertions(+), 20 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 1cdcbbb..447685e 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;
/**
@@ -66,7 +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);
@@ -108,15 +109,16 @@
} 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);
- decodedRedirectUri = getNormalizedRedirectUri(decodedRedirectUri);
+ 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, true);
+ 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();
@@ -133,17 +135,28 @@
}
// 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(redirectUri);
+ 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) {
+ if (valid == null) {
valid = matchesRedirects(resolveValidRedirects, redirectUri, false);
}
- if (valid && redirectUri.startsWith("/")) {
+ 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)) {
@@ -153,18 +166,24 @@
}
}
- private static String getNormalizedRedirectUri(String redirectUri) {
+ private static URI toUri(String redirectUri) {
+ URI uri = null;
if (redirectUri != null) {
- try {
- URI uri = URI.create(redirectUri);
- redirectUri = uri.normalize().toString();
+ try {
+ uri = URI.create(redirectUri);
} 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;
}
+ }
+ return uri;
+ }
+
+ private static String getNormalizedRedirectUri(URI uri) {
+ String redirectUri = null;
+ if (uri != null) {
+ redirectUri = uri.normalize().toString();
redirectUri = lowerCaseHostname(redirectUri);
}
return redirectUri;
@@ -229,7 +248,8 @@
return sb.toString();
}
- private static boolean matchesRedirects(Set<String> validRedirects, String redirect, boolean allowWildcards) {
+ // 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("?") && allowWildcards) {
@@ -238,14 +258,14 @@
// 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) {
--
Gitblit v1.10.0