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Merged
edewit merged 1 commit into from
Sep 27, 2023
Merged

Always check storage access before placing test cookie #23558

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9 changes: 7 additions & 2 deletions js/libs/keycloak-js/src/keycloak.js
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Original file line number Diff line number Diff line change
Expand Up @@ -1298,12 +1298,17 @@ function Keycloak (config) {
if (event.data !== "supported" && event.data !== "unsupported") {
return;
} else if (event.data === "unsupported") {
logWarn(
"[KEYCLOAK] Your browser is blocking access to 3rd-party cookies, this means:\n\n" +
" - It is not possible to retrieve tokens without redirecting to the Keycloak server (a.k.a. no support for silent authentication).\n" +
" - It is not possible to automatically detect changes to the session status (such as the user logging out in another tab).\n\n" +
"For more information see: https://www.keycloak.org/docs/latest/securing_apps/#_modern_browsers"
);

loginIframe.enable = false;
if (kc.silentCheckSsoFallback) {
kc.silentCheckSsoRedirectUri = false;
}
logWarn("[KEYCLOAK] 3rd party cookies aren't supported by this browser. checkLoginIframe and " +
"silent check-sso are not available.")
}

document.body.removeChild(iframe);
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54 changes: 15 additions & 39 deletions services/src/main/resources/org/keycloak/protocol/oidc/endpoints/3p-cookies-step1.html
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Original file line number Diff line number Diff line change
@@ -1,66 +1,42 @@
<!doctype html>
<html>
<head>
<meta charset="utf-8" />
<meta charset="utf-8">
</head>
<body>
<script type="module">
// Check if the browser has granted us access to 3rd-party storage (such as cookies).
if (await hasStorageAccess()) {
// If so, signal support to the page embedding this iframe.
window.parent.postMessage("supported", "*");
} else {
// Otherwise, attempt to place a test cookie to verify support.
const hasAccess = await hasStorageAccess();

if (hasAccess) {
// If so, attempt to place a cookie to test this assumption.
attemptWithTestCookie();
} else {
// Otherwise, signal that 3rd-party access is not supported.
signalSupport(false);
}

// See: https://developer.mozilla.org/en-US/docs/Web/API/Storage_Access_API/Using
async function hasStorageAccess() {
// If the Storage Access API is not implemented, assume we don't have access.
if (!("hasStorageAccess" in document)) {
return false;
}

const hasAccess = await document.hasStorageAccess();

// If we have access to unpartitioned cookies, signal support.
if (hasAccess) {
return true;
}

// Otherwise, check whether unpartitioned cookie access has been granted to another same-site embed.
let permission;

try {
permission = await navigator.permissions.query({
name: "storage-access",
});
} catch (error) {
return false;
}

// If not, signal that there is no support.
if (permission.state !== "granted") {
return false;
}

// Otherwise, call requestStorageAccess() without a user interaction, and it should resolve automatically.
// But just to be sure, handle a possible exception in case this behavior changes in the future.
try {
await document.requestStorageAccess();
return true;
} catch (error) {
return false;
}
return document.hasStorageAccess();
}

function attemptWithTestCookie() {
// Place a cookie to test whether we can access cookies from 3rd-party storage.
document.cookie = "KEYCLOAK_3P_COOKIE_SAMESITE=supported; Max-Age=60; SameSite=None; Secure";
document.cookie = "KEYCLOAK_3P_COOKIE=supported; Max-Age=60";

// Then redirect to the page where we will read these cookies to confirm this.
window.location = "step2.html";
}

function signalSupport(isSupported) {
// Signal 3rd-party access support to the page embedding this iframe.
window.parent.postMessage(isSupported ? "supported" : "unsupported", "*");
}
</script>
</body>
</html>
2 changes: 1 addition & 1 deletion services/src/main/resources/org/keycloak/protocol/oidc/endpoints/3p-cookies-step2.html
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Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
<!doctype html>
<html>
<head>
<meta charset="utf-8" />
<meta charset="utf-8">
</head>
<body>
<script type="module">
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21 changes: 19 additions & 2 deletions services/src/main/resources/org/keycloak/protocol/oidc/endpoints/login-status-iframe.html
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Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
<!doctype html>
<html>
<head>
<meta charset="utf-8" />
<meta charset="utf-8">
</head>
<body>
<script type="module">
Expand Down Expand Up @@ -30,7 +30,14 @@
let init;

async function checkState(clientId, origin, sessionState) {
const cookie = getSessionCookie();
// Check if the browser has granted us access to 3rd-party storage (such as cookies).
const hasAccess = await hasStorageAccess();

// If we don't have access, signal an error.
// As we cannot read cookies, we cannot verify the session state.
if (!hasAccess) {
return "error";
}

// If not initialized, verify this client is allowed access with a call to the server.
if (!init) {
Expand All @@ -48,6 +55,8 @@
init = { clientId, origin };
}

const cookie = getSessionCookie();

// Signal a change in state if there is no cookie, and the session state is not empty.
if (!cookie) {
return sessionState !== "" ? "changed" : "unchanged";
Expand All @@ -63,6 +72,14 @@
return "error";
}

async function hasStorageAccess() {
if (!("hasStorageAccess" in document)) {
return true;
}

return document.hasStorageAccess();
}

function getSessionCookie() {
const cookie = getCookieByName("KEYCLOAK_SESSION");

Expand Down