Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 224 insertions, 0 deletions

diff --git a/services/fxaccounts/FxAccountsOAuth.sys.mjs b/services/fxaccounts/FxAccountsOAuth.sys.mjs
new file mode 100644
index 0000000000..1935decff2
--- /dev/null
+++ b/services/fxaccounts/FxAccountsOAuth.sys.mjs
@@ -0,0 +1,224 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  jwcrypto: "resource://services-crypto/jwcrypto.sys.mjs",
+});
+
+import {
+  FX_OAUTH_CLIENT_ID,
+  SCOPE_PROFILE,
+  SCOPE_PROFILE_WRITE,
+  SCOPE_OLD_SYNC,
+} from "resource://gre/modules/FxAccountsCommon.sys.mjs";
+
+const VALID_SCOPES = [SCOPE_PROFILE, SCOPE_PROFILE_WRITE, SCOPE_OLD_SYNC];
+
+export const ERROR_INVALID_SCOPES = "INVALID_SCOPES";
+export const ERROR_INVALID_STATE = "INVALID_STATE";
+export const ERROR_SYNC_SCOPE_NOT_GRANTED = "ERROR_SYNC_SCOPE_NOT_GRANTED";
+export const ERROR_NO_KEYS_JWE = "ERROR_NO_KEYS_JWE";
+export const ERROR_OAUTH_FLOW_ABANDONED = "ERROR_OAUTH_FLOW_ABANDONED";
+
+/**
+ * Handles all logic and state related to initializing, and completing OAuth flows
+ * with FxA
+ * It's possible to start multiple OAuth flow, but only one can be completed, and once one flow is completed
+ * all the other in-flight flows will be concluded, and attempting to complete those flows will result in errors.
+ */
+export class FxAccountsOAuth {
+  #flow;
+  #fxaClient;
+  /**
+   * Creates a new FxAccountsOAuth
+   *
+   * @param { Object } fxaClient: The fxa client used to send http request to the oauth server
+   */
+  constructor(fxaClient) {
+    this.#flow = {};
+    this.#fxaClient = fxaClient;
+  }
+
+  /**
+   * Stores a flow in-memory
+   * @param { string } state: A base-64 URL-safe string represnting a random value created at the start of the flow
+   * @param { Object } value: The data needed to complete a flow, once the oauth code is available.
+   * in practice, `value` is:
+   *  - `verifier`: A base=64 URL-safe string representing the PKCE code verifier
+   *  - `key`: The private key need to decrypt the JWE we recieve from the auth server
+   *  - `requestedScopes`: The scopes the caller requested, meant to be compared against the scopes the server authorized
+   */
+  addFlow(state, value) {
+    this.#flow[state] = value;
+  }
+
+  /**
+   * Clears all started flows
+   */
+  clearAllFlows() {
+    this.#flow = {};
+  }
+
+  /*
+   * Gets a stored flow
+   * @param { string } state: The base-64 URL-safe state string that was created at the start of the flow
+   * @returns { Object }: The values initially stored when startign th eoauth flow
+   * in practice, the return value is:
+   *  - `verifier`: A base=64 URL-safe string representing the PKCE code verifier
+   *  - `key`: The private key need to decrypt the JWE we recieve from the auth server
+   *  - ``requestedScopes`: The scopes the caller requested, meant to be compared against the scopes the server authorized
+   */
+  getFlow(state) {
+    return this.#flow[state];
+  }
+
+  /* Returns the number of flows, used by tests
+   *
+   */
+  numOfFlows() {
+    return Object.keys(this.#flow).length;
+  }
+
+  /**
+   * Begins an OAuth flow, to be completed with a an OAuth code and state.
+   *
+   * This function stores needed information to complete the flow. You must call `completeOAuthFlow`
+   * on the same instance of `FxAccountsOAuth`, otherwise the completing of the oauth flow will fail.
+   *
+   * @param { string[] } scopes: The OAuth scopes the client should request from FxA
+   *
+   * @returns { Object }: Returns an object representing the query parameters that should be
+   *     added to the FxA authorization URL to initialize an oAuth flow.
+   *     In practice, the query parameters are:
+   *       - `client_id`: The OAuth client ID for Firefox Desktop
+   *       - `scope`: The scopes given by the caller, space seperated
+   *       - `action`: This will always be `email`
+   *       - `response_type`: This will always be `code`
+   *       - `access_type`: This will always be `offline`
+   *       - `state`: A URL-safe base-64 string randomly generated
+   *       - `code_challenge`: A URL-safe base-64 string representing the PKCE challenge
+   *       - `code_challenge_method`: This will always be `S256`
+   *          For more informatio about PKCE, read https://datatracker.ietf.org/doc/html/rfc7636
+   *       - `keys_jwk`: A URL-safe base-64 representing a JWK to be used as a public key by the server
+   *          to generate a JWE
+   */
+  async beginOAuthFlow(scopes) {
+    if (
+      !Array.isArray(scopes) ||
+      scopes.some(scope => !VALID_SCOPES.includes(scope))
+    ) {
+      throw new Error(ERROR_INVALID_SCOPES);
+    }
+    const queryParams = {
+      client_id: FX_OAUTH_CLIENT_ID,
+      action: "email",
+      response_type: "code",
+      access_type: "offline",
+      scope: scopes.join(" "),
+    };
+
+    // Generate a random, 16 byte value to represent a state that we verify
+    // once we complete the oauth flow, to ensure that we only conclude
+    // an oauth flow that we started
+    const state = new Uint8Array(16);
+    crypto.getRandomValues(state);
+    const stateB64 = ChromeUtils.base64URLEncode(state, { pad: false });
+    queryParams.state = stateB64;
+
+    // Generate a 43 byte code verifier for PKCE, in accordance with
+    // https://datatracker.ietf.org/doc/html/rfc7636#section-7.1 which recommends a
+    // 43-octet URL safe string
+    const codeVerifier = new Uint8Array(43);
+    crypto.getRandomValues(codeVerifier);
+    const codeVerifierB64 = ChromeUtils.base64URLEncode(codeVerifier, {
+      pad: false,
+    });
+    const challenge = await crypto.subtle.digest(
+      "SHA-256",
+      new TextEncoder().encode(codeVerifierB64)
+    );
+    const challengeB64 = ChromeUtils.base64URLEncode(challenge, { pad: false });
+    queryParams.code_challenge = challengeB64;
+    queryParams.code_challenge_method = "S256";
+
+    // Generate a public, private key pair to be used during the oauth flow
+    // to encrypt scoped-keys as they roundtrip through the auth server
+    const ECDH_KEY = { name: "ECDH", namedCurve: "P-256" };
+    const key = await crypto.subtle.generateKey(ECDH_KEY, true, ["deriveKey"]);
+    const publicKey = await crypto.subtle.exportKey("jwk", key.publicKey);
+    const privateKey = key.privateKey;
+
+    // We encode the public key as URL-safe base64 to be included in the query parameters
+    const encodedPublicKey = ChromeUtils.base64URLEncode(
+      new TextEncoder().encode(JSON.stringify(publicKey)),
+      { pad: false }
+    );
+    queryParams.keys_jwk = encodedPublicKey;
+
+    // We store the state in-memory, to verify once the oauth flow is completed
+    this.addFlow(stateB64, {
+      key: privateKey,
+      verifier: codeVerifierB64,
+      requestedScopes: scopes.join(" "),
+    });
+    return queryParams;
+  }
+
+  /** Completes an OAuth flow and invalidates any other ongoing flows
+   * @param { string } sessionTokenHex: The session token encoded in hexadecimal
+   * @param { string } code: OAuth authorization code provided by running an OAuth flow
+   * @param { string } state: The state first provided by `beginOAuthFlow`, then roundtripped through the server
+   *
+   * @returns { Object }: Returns an object representing the result of completing the oauth flow.
+   *   The object includes the following:
+   *     - 'scopedKeys': The encryption keys provided by the server, already decrypted
+   *     - 'refreshToken': The refresh token provided by the server
+   *     - 'accessToken': The access token provided by the server
+   * */
+  async completeOAuthFlow(sessionTokenHex, code, state) {
+    const flow = this.getFlow(state);
+    if (!flow) {
+      throw new Error(ERROR_INVALID_STATE);
+    }
+    const { key, verifier, requestedScopes } = flow;
+    const { keys_jwe, refresh_token, access_token, scope } =
+      await this.#fxaClient.oauthToken(
+        sessionTokenHex,
+        code,
+        verifier,
+        FX_OAUTH_CLIENT_ID
+      );
+    if (
+      requestedScopes.includes(SCOPE_OLD_SYNC) &&
+      !scope.includes(SCOPE_OLD_SYNC)
+    ) {
+      throw new Error(ERROR_SYNC_SCOPE_NOT_GRANTED);
+    }
+    if (scope.includes(SCOPE_OLD_SYNC) && !keys_jwe) {
+      throw new Error(ERROR_NO_KEYS_JWE);
+    }
+    let scopedKeys;
+    if (keys_jwe) {
+      scopedKeys = JSON.parse(
+        new TextDecoder().decode(await lazy.jwcrypto.decryptJWE(keys_jwe, key))
+      );
+    }
+
+    // We make sure no other flow snuck in, and completed before we did
+    if (!this.getFlow(state)) {
+      throw new Error(ERROR_OAUTH_FLOW_ABANDONED);
+    }
+
+    // Clear all flows, so any in-flight or future flows trigger an error as the browser
+    // would have been signed in
+    this.clearAllFlows();
+    return {
+      scopedKeys,
+      refreshToken: refresh_token,
+      accessToken: access_token,
+    };
+  }
+}