fix(security): migrate MCP pairing token from storage.local to storage.session#63
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Code Review
This pull request migrates MCP pairing storage from chrome.storage.local to chrome.storage.session and introduces a storage migration function along with corresponding unit tests. The review feedback highlights a critical bug where the migration function reads the wrong legacy keys ("mcp_pairing_token_v1" and "mcp_pairing_port_v1" instead of "mcpToken" and "mcpPort"), which is also masked by the new unit tests. Additionally, the reviewer suggests handling environments where chrome.storage.session is unsupported to prevent silent failures and runtime errors.
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| export async function migrateLegacyStorage() { | ||
| if (typeof chrome === "undefined" || !chrome.storage) return; | ||
| const local = await chrome.storage.local.get([TOKEN_KEY, PORT_KEY]); | ||
| if (local[TOKEN_KEY] || local[PORT_KEY]) { | ||
| await chrome.storage.session.set({ | ||
| [TOKEN_KEY]: local[TOKEN_KEY], | ||
| [PORT_KEY]: local[PORT_KEY], | ||
| }); | ||
| await chrome.storage.local.remove([TOKEN_KEY, PORT_KEY]); | ||
| } | ||
| } |
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The migration function migrateLegacyStorage is attempting to read TOKEN_KEY ("mcp_pairing_token_v1") and PORT_KEY ("mcp_pairing_port_v1") from chrome.storage.local. However, in the legacy implementation, these values were stored under the keys "mcpToken" and "mcpPort".
As a result, the migration will never find the legacy pairing token and port, and existing paired users will lose their pairing state.
Additionally, if chrome.storage.session is undefined (e.g., in environments where it is not supported or not enabled), calling chrome.storage.session.set will throw a TypeError, causing the promise to reject and preventing performPairing() from running.
We should:
- Read the correct legacy keys (
"mcpToken"and"mcpPort") fromchrome.storage.local. - Add a check for
chrome.storage.sessionto avoid runtime errors. - Wrap the migration in a
try/catchblock to ensure that any storage errors do not block the pairing process.
export async function migrateLegacyStorage() {
if (typeof chrome === "undefined" || !chrome.storage || !chrome.storage.local || !chrome.storage.session) return;
try {
const LEGACY_TOKEN_KEY = "mcpToken";
const LEGACY_PORT_KEY = "mcpPort";
const local = await chrome.storage.local.get([LEGACY_TOKEN_KEY, LEGACY_PORT_KEY]);
if (local[LEGACY_TOKEN_KEY] || local[LEGACY_PORT_KEY]) {
await chrome.storage.session.set({
[TOKEN_KEY]: local[LEGACY_TOKEN_KEY],
[PORT_KEY]: local[LEGACY_PORT_KEY],
});
await chrome.storage.local.remove([LEGACY_TOKEN_KEY, LEGACY_PORT_KEY]);
}
} catch (err) {
console.error("Failed to migrate legacy MCP pairing storage:", err);
}
}
| it("token does not appear in chrome.storage.local after migration", async () => { | ||
| mockLocalStorage["mcp_pairing_token_v1"] = VALID_TOKEN; | ||
| mockLocalStorage["mcp_pairing_port_v1"] = "65000"; | ||
|
|
||
| const { migrateLegacyStorage } = await import("../panel/components/MCPPairingPanel"); | ||
| await migrateLegacyStorage(); | ||
|
|
||
| expect(mockLocalStorage["mcp_pairing_token_v1"]).toBeUndefined(); | ||
| expect(mockLocalStorage["mcp_pairing_port_v1"]).toBeUndefined(); | ||
| expect(mockSessionStorage["mcp_pairing_token_v1"]).toBe(VALID_TOKEN); | ||
| }); |
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The test sets up mockLocalStorage using the new keys ("mcp_pairing_token_v1" and "mcp_pairing_port_v1") instead of the actual legacy keys ("mcpToken" and "mcpPort"). This masked the bug in the migration function.
We should update the test to use the actual legacy keys to ensure the migration is tested correctly.
| it("token does not appear in chrome.storage.local after migration", async () => { | |
| mockLocalStorage["mcp_pairing_token_v1"] = VALID_TOKEN; | |
| mockLocalStorage["mcp_pairing_port_v1"] = "65000"; | |
| const { migrateLegacyStorage } = await import("../panel/components/MCPPairingPanel"); | |
| await migrateLegacyStorage(); | |
| expect(mockLocalStorage["mcp_pairing_token_v1"]).toBeUndefined(); | |
| expect(mockLocalStorage["mcp_pairing_port_v1"]).toBeUndefined(); | |
| expect(mockSessionStorage["mcp_pairing_token_v1"]).toBe(VALID_TOKEN); | |
| }); | |
| it("token does not appear in chrome.storage.local after migration", async () => { | |
| mockLocalStorage["mcpToken"] = VALID_TOKEN; | |
| mockLocalStorage["mcpPort"] = "65000"; | |
| const { migrateLegacyStorage } = await import("../panel/components/MCPPairingPanel"); | |
| await migrateLegacyStorage(); | |
| expect(mockLocalStorage["mcpToken"]).toBeUndefined(); | |
| expect(mockLocalStorage["mcpPort"]).toBeUndefined(); | |
| expect(mockSessionStorage["mcp_pairing_token_v1"]).toBe(VALID_TOKEN); | |
| }); |
| try { | ||
| if (typeof chrome !== "undefined" && chrome.storage?.session) { | ||
| await savePairing(token!, port!); | ||
| } | ||
| window.history.replaceState(null, "", window.location.pathname); | ||
| setPaired(true); | ||
| setErrors([]); | ||
| } catch (err) { | ||
| setErrors([{ | ||
| code: "storage-failed", | ||
| message: "Could not save pairing.", | ||
| fix: (err as Error).message, | ||
| }]); | ||
| } |
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If chrome is defined (meaning we are in an extension context) but chrome.storage.session is undefined (e.g., in older browser versions or unsupported environments), the code will silently skip saving the pairing token but still set paired to true and clear the hash. This leads to a silent failure where the user thinks pairing succeeded but the token was never saved.
We should throw an error if chrome.storage.session is missing in an extension context so that the failure is captured and displayed to the user.
| try { | |
| if (typeof chrome !== "undefined" && chrome.storage?.session) { | |
| await savePairing(token!, port!); | |
| } | |
| window.history.replaceState(null, "", window.location.pathname); | |
| setPaired(true); | |
| setErrors([]); | |
| } catch (err) { | |
| setErrors([{ | |
| code: "storage-failed", | |
| message: "Could not save pairing.", | |
| fix: (err as Error).message, | |
| }]); | |
| } | |
| try { | |
| if (typeof chrome !== "undefined") { | |
| if (!chrome.storage?.session) { | |
| throw new Error("chrome.storage.session is not supported in this browser version."); | |
| } | |
| await savePairing(token!, port!); | |
| } | |
| window.history.replaceState(null, "", window.location.pathname); | |
| setPaired(true); | |
| setErrors([]); | |
| } catch (err) { | |
| setErrors([{ | |
| code: "storage-failed", | |
| message: "Could not save pairing.", | |
| fix: (err as Error).message, | |
| }]); | |
| } |
hoainho
added
the
pre-star-rule
|
Hey @iMindCap — welcome back after 7 days! 🎉 The CI is showing a false-negative on the Star Check (read-replica lag — your star is definitely there, verified in the stargazer list, but the API can't see it for ~30s+). I've applied the Security review — the change is solid ✅I read the full diff carefully (security work always gets a closer look). What I verified:
One forward-looking note (no change required)
Why this matters
Going to merge once CI re-runs (should be ~30s). Issue #42 will auto-close. Welcome to the contributors list! 🎉 — Hoài |
2 participants
Closes #42
Type of change
What changed
Migrates MCP pairing token from
chrome.storage.localtochrome.storage.session.Tokens now clear on browser restart and are no longer readable by other extensions. Includes a one-time migration helper that moves any legacy token from local to session on panel load.Testing notes
$ npx vitest run src/tests/MCPPairingPanel.test.tsx
Test Files 1 passed (1)
Tests 9 passed (9)
Checklist
npm run test:runpasses locally (or pre-existing failures are unrelated to this change)npm run buildsucceeds locally## [Unreleased](skip for docs-only or test-only PRs)fix(panel): ...)Additional notes
Token is also cleared from the URL hash after successful pairing via window.history.replaceState (OWASP ASVS 3.1.1).