quak login --server: log in to a self-hosted Ente server (closes #243)

`quak login` takes the server's API address from `--server` or
`QUAK_SERVER`, refusing anything that is not an http or https URL. The
client's snapshot now keeps a non-default `apiOrigin`, so the session
file names the server and every later command uses it. A snapshot's
`apiOrigin` wins over the one in `fromJSON`'s `apiOptions`, since the
token belongs to that server.

Model: opus-5-5

README.md

@@ -229,7 +229,7 @@ below belong to quak itself, and go before or after the command's name.
 ### The commands
 
 ```
-quak login
+quak login [--server <url>]
 quak whoami
 quak logout
 quak collections [--json]
@@ -246,13 +246,26 @@ Every command but `login` and `logout` needs a saved session. Every command but
 `login`, `whoami` and `logout` opens the library. How each one gets current data
 from the server is described under "How a command gets current data".
 
-#### `quak login`
+#### `quak login [--server <url>]`
 
 Logs in to an account and saves the session. It reads the email from
 `QUAK_EMAIL` and the password from `QUAK_PASSWORD`. For each one that is not
 set, it asks on the terminal. The password shows as `*` characters while it is
 typed.
 
+quak logs in to Ente's hosted service unless you name a self-hosted Ente server.
+Name it with `--server`, or with `QUAK_SERVER` when `--server` is not given.
+Give the address of the server's API, for example
+`quak login --server https://ente.example.com`. The address is an http or https
+URL. It may include a path, but no query or fragment. quak refuses any other
+address before it asks for anything. It logs
+`Invalid server address "<url>": it must be an http or https URL with no query or fragment`,
+and the exit status is 1.
+
+The session file keeps the server's address. Every later command, cron runs
+included, uses that server without further setting. To change server, log in
+again.
+
 When the account has a second factor, quak asks for the code. It asks
 `TOTP code: ` for a time-based code from an authenticator app. An account whose
 only second factor is a passkey cannot log in with quak. When the account has
@@ -597,9 +610,11 @@ Linux that is `$XDG_DATA_HOME/quak/session.json`, or
 mode `0600`, in a directory it creates with mode `0700`.
 
 The file holds the account's email, its user ID, the session token and the
-account's three keys, in base64 and unencrypted. Treat it as you would treat the
-password. A missing file means "not logged in". A file that cannot be read back
-is reported as corrupt, with the reason. Run `quak logout`, then `quak login`.
+account's three keys, in base64 and unencrypted. After a login to a self-hosted
+server, it also holds the server's address as `apiOrigin`. Treat it as you would
+treat the password. A missing file means "not logged in". A file that cannot be
+read back is reported as corrupt, with the reason. Run `quak logout`, then
+`quak login`.
 
 A command that needs a session exits 3 when the file is missing or corrupt. It
 also exits 3 when the server no longer accepts the session, and prints
@@ -1477,6 +1492,11 @@ write wherever it likes. `Client.fromJSON(snapshot, apiOptions?)` restores a
 working client from that snapshot without logging in again. It checks every
 field and each key's length first, and throws an error naming the bad field.
 
+A client whose `apiOptions` named an `apiOrigin` puts it in its snapshot. The
+restored client then uses that server, even when the `apiOptions` given to
+`Client.fromJSON` name another. A snapshot without `apiOrigin` uses the
+`apiOrigin` of those `apiOptions`, or the default server.
+
 `Client.fromJSON` works only once libsodium, the cryptography library quak uses,
 is loaded. `Client.login` loads it, and `Client.fromJSON` does not. A program
 that restores a session in a new process first runs `await sodium.ready`, with

bin/quak.ts

@@ -74,7 +74,11 @@ const context = (): CliContext => ({
     sessionDir: paths.data,
     cacheDir: program.opts<ProgramOptions>().cacheDir,
     loadSession: (path) => loadSession(path, logRequests(log())),
-    login: (opts) => Client.login({ ...opts, apiOptions: logRequests(log()) }),
+    login: (opts) =>
+        Client.login({
+            ...opts,
+            apiOptions: { ...opts.apiOptions, ...logRequests(log()) },
+        }),
     prompt: (message) => input({ message }),
     promptSecret: (message) => password({ message, mask: true }),
 });
@@ -85,7 +89,12 @@ const run = (command: Promise<number>): Promise<void> =>
 program
     .command("login")
     .description("Log in to an Ente account and save the session")
-    .action(() => run(loginCommand(context())));
+    .option(
+        "--server <url>",
+        "Address of a self-hosted Ente server's API, saved with the session " +
+            "(default: QUAK_SERVER, then Ente's hosted service)",
+    )
+    .action((opts: { server?: string }) => run(loginCommand(context(), opts)));
 
 program
     .command("whoami")

src/cli-commands.ts

@@ -155,8 +155,31 @@ const openReadLibrary = (ctx: CliContext, client: Client): Promise<Library> =>
         onProgress: logRefresh(ctx.log),
     });
 
-export const loginCommand = async (ctx: CliContext): Promise<number> => {
+// Logs in to the server `--server` or `QUAK_SERVER` names, the flag first, or
+// to Ente's hosted service when neither is set. The saved session keeps the
+// server, so every later command uses it.
+// Whether `text` can be an Ente server's address: an http or https URL, which
+// may have a path, and no query or fragment, which request URLs could not
+// carry.
+const isServerAddress = (text: string): boolean =>
+    URL.canParse(text) &&
+    ["http:", "https:"].includes(new URL(text).protocol) &&
+    !/[?#]/.test(text);
+
+export const loginCommand = async (
+    ctx: CliContext,
+    opts: { server?: string },
+): Promise<number> => {
     await init();
+    const server = opts.server ?? process.env.QUAK_SERVER;
+    if (server !== undefined && !isServerAddress(server)) {
+        ctx.log(
+            "fatal",
+            `Invalid server address "${server}": it must be an http or ` +
+                `https URL with no query or fragment`,
+        );
+        return 1;
+    }
     const email = process.env.QUAK_EMAIL ?? (await ctx.prompt("Email"));
     const password =
         process.env.QUAK_PASSWORD ?? (await ctx.promptSecret("Password"));
@@ -168,6 +191,8 @@ export const loginCommand = async (ctx: CliContext): Promise<number> => {
             password,
             totp: async () => ctx.prompt("TOTP code: "),
             emailOTP: async () => ctx.prompt("Email verification code: "),
+            apiOptions:
+                server === undefined ? undefined : { apiOrigin: server },
         });
 
         saveSession(ctx.sessionDir, client.toJSON());

src/client.ts

@@ -40,6 +40,9 @@ export interface ClientSnapshot {
     masterKey: string;
     secretKey: string;
     publicKey: string;
+    // The `apiOrigin` the client was given, so a restored client talks to
+    // the server that issued its token. Absent means the default server.
+    apiOrigin?: string;
 }
 
 // The result of a resumable enumeration. Live decrypted records and deleted
@@ -73,6 +76,7 @@ export class Client {
     private readonly masterKey: Uint8Array;
     private readonly secretKey: Uint8Array;
     private readonly publicKey: Uint8Array;
+    private readonly apiOrigin: string | undefined;
     private loggedOut = false;
 
     private constructor(
@@ -82,6 +86,7 @@ export class Client {
         masterKey: Uint8Array,
         secretKey: Uint8Array,
         publicKey: Uint8Array,
+        apiOrigin: string | undefined,
     ) {
         this.api = api;
         this.email = email;
@@ -89,6 +94,7 @@ export class Client {
         this.masterKey = masterKey;
         this.secretKey = secretKey;
         this.publicKey = publicKey;
+        this.apiOrigin = apiOrigin;
     }
 
     static async login(opts: LoginOptions): Promise<Client> {
@@ -130,12 +136,15 @@ export class Client {
             unwrapped.masterKey,
             unwrapped.secretKey,
             unwrapped.publicKey,
+            opts.apiOptions?.apiOrigin,
         );
     }
 
     // Restore a client from a `toJSON()` snapshot. The snapshot usually comes
     // straight from `JSON.parse` of a file on disk, so every field is checked
-    // before use; a bad one throws an error naming it. Needs `init()` first.
+    // before use; a bad one throws an error naming it. The snapshot's
+    // `apiOrigin`, when it has one, is used instead of `apiOptions.apiOrigin`.
+    // Needs `init()` first.
     static fromJSON(snapshot: unknown, apiOptions?: ApiClientOptions): Client {
         const invalid = (field: string, problem: string): Error =>
             new Error(`Invalid session data: ${field} ${problem}`);
@@ -152,6 +161,14 @@ export class Client {
         if (!Number.isInteger(s.userID)) {
             throw invalid("userID", "must be an integer");
         }
+        if (
+            s.apiOrigin !== undefined &&
+            (typeof s.apiOrigin !== "string" || s.apiOrigin === "")
+        ) {
+            throw invalid("apiOrigin", "must be a non-empty string");
+        }
+        const apiOrigin =
+            (s.apiOrigin as string | undefined) ?? apiOptions?.apiOrigin;
         const key = (field: string): Uint8Array => {
             const value = s[field];
             if (typeof value !== "string") {
@@ -175,6 +192,7 @@ export class Client {
 
         const api = new ApiClient({
             ...apiOptions,
+            apiOrigin,
             authToken: s.token as string,
         });
         return new Client(
@@ -184,6 +202,7 @@ export class Client {
             key("masterKey"),
             key("secretKey"),
             key("publicKey"),
+            apiOrigin,
         );
     }
 
@@ -222,6 +241,9 @@ export class Client {
             masterKey: toBase64(this.masterKey),
             secretKey: toBase64(this.secretKey),
             publicKey: toBase64(this.publicKey),
+            ...(this.apiOrigin === undefined
+                ? {}
+                : { apiOrigin: this.apiOrigin }),
         };
     }
 

test/cli/bin.test.ts

@@ -2,8 +2,9 @@
  * Tests for the retry options `bin/quak.ts` loads the saved session with
  * (`quak backup` gets the unattended ones, every other command the default),
  * each with the callbacks that log its requests and retries, for `quak files`
- * taking its collection ID as an optional argument, and for `quak get` and
- * `quak get-thumb` refusing `--collection`.
+ * taking its collection ID as an optional argument, for `quak get` and
+ * `quak get-thumb` refusing `--collection`, and for `quak login` taking
+ * `--server`.
  *
  * Each test runs `bin/quak.ts`, as the smoke test does, with its session loader
  * replaced by one that records the options it is given and reports no session,
@@ -117,3 +118,13 @@ describe("bin/quak.ts get and get-thumb", () => {
         },
     );
 });
+
+// The command refuses an address that is not a URL before it asks for anything
+// or sends any request.
+describe("bin/quak.ts login", () => {
+    it("hands --server to the command", async () => {
+        expect(await quak("login", "--server", "ente.example.com")).toMatch(
+            /^Invalid server address "ente\.example\.com"/,
+        );
+    });
+});

test/cli/commands.test.ts

@@ -328,6 +328,7 @@ describe("login", () => {
         prompts = [];
         vi.stubEnv("QUAK_EMAIL", "cli@example.com");
         vi.stubEnv("QUAK_PASSWORD", "hunter2");
+        vi.stubEnv("QUAK_SERVER", undefined);
     });
 
     afterEach(() => {
@@ -340,12 +341,14 @@ describe("login", () => {
             calls.push(opts);
             return loggedIn;
         });
-        expect(await loginCommand(ctx)).toBe(0);
+        expect(await loginCommand(ctx, {})).toBe(0);
 
         expect(prompts).toEqual([]);
         expect(calls).toHaveLength(1);
         expect(calls[0]!.email).toBe("cli@example.com");
         expect(calls[0]!.password).toBe("hunter2");
+        // No server named: the client uses Ente's hosted service.
+        expect(calls[0]!.apiOptions).toBeUndefined();
         const path = join(ctx.sessionDir, "session.json");
         expect(stderr.text).toBe(
             "Authenticating...\n" +
@@ -356,7 +359,7 @@ describe("login", () => {
 
     it("saves the session with mode 0600 in a directory with mode 0700", async () => {
         const ctx = loginContext(async () => loggedIn);
-        expect(await loginCommand(ctx)).toBe(0);
+        expect(await loginCommand(ctx, {})).toBe(0);
 
         expect(statSync(ctx.sessionDir).mode & 0o777).toBe(0o700);
         const path = join(ctx.sessionDir, "session.json");
@@ -370,7 +373,7 @@ describe("login", () => {
             code = await opts.totp!();
             return loggedIn;
         });
-        expect(await loginCommand(ctx)).toBe(0);
+        expect(await loginCommand(ctx, {})).toBe(0);
 
         expect(prompts).toEqual(["TOTP code: "]);
         expect(code).toBe("123456");
@@ -380,13 +383,68 @@ describe("login", () => {
         const ctx = loginContext(async () => {
             throw new Error("HTTP 401 from server");
         });
-        expect(await loginCommand(ctx)).toBe(1);
+        expect(await loginCommand(ctx, {})).toBe(1);
 
         expect(stderr.text).toBe(
             "Authenticating...\nLogin failed: HTTP 401 from server\n",
         );
         expect(existsSync(join(ctx.sessionDir, "session.json"))).toBe(false);
     });
+
+    it("logs in to the server --server names, ahead of QUAK_SERVER", async () => {
+        vi.stubEnv("QUAK_SERVER", "https://other.example.com");
+        const calls: LoginOptions[] = [];
+        const ctx = loginContext(async (opts) => {
+            calls.push(opts);
+            return loggedIn;
+        });
+        expect(
+            await loginCommand(ctx, { server: "https://ente.example.com" }),
+        ).toBe(0);
+
+        expect(calls[0]!.apiOptions).toEqual({
+            apiOrigin: "https://ente.example.com",
+        });
+    });
+
+    it("logs in to the server QUAK_SERVER names without --server", async () => {
+        vi.stubEnv("QUAK_SERVER", "http://192.0.2.1:8080/ente");
+        const calls: LoginOptions[] = [];
+        const ctx = loginContext(async (opts) => {
+            calls.push(opts);
+            return loggedIn;
+        });
+        expect(await loginCommand(ctx, {})).toBe(0);
+
+        expect(calls[0]!.apiOptions).toEqual({
+            apiOrigin: "http://192.0.2.1:8080/ente",
+        });
+    });
+
+    it.each([
+        "",
+        "ente.example.com",
+        "ftp://ente.example.com",
+        "https://ente.example.com/?region=eu",
+        "https://ente.example.com/#top",
+    ])(
+        "refuses the server address %j before asking for anything",
+        async (server) => {
+            const ctx = loginContext(async () => {
+                throw new Error("login must not be called");
+            });
+            expect(await loginCommand(ctx, { server })).toBe(1);
+
+            expect(prompts).toEqual([]);
+            expect(stderr.text).toBe(
+                `Invalid server address "${server}": it must be an http or ` +
+                    `https URL with no query or fragment\n`,
+            );
+            expect(existsSync(join(ctx.sessionDir, "session.json"))).toBe(
+                false,
+            );
+        },
+    );
 });
 
 // These use a real client read from the session file, over a fake API that
@@ -1851,6 +1909,47 @@ describe("an account with many albums", () => {
         expect(existsSync(join(root, "cache", "metadata.json"))).toBe(false);
     });
 
+    // A self-hosted server serves downloads under its own address, at
+    // `/files/download/<id>`, so no request goes to Ente's hosted service.
+    it("login --server saves the server, and a later get sends every request to it", async () => {
+        vi.stubEnv("QUAK_EMAIL", "many@example.com");
+        vi.stubEnv("QUAK_PASSWORD", PASSWORD);
+        vi.stubEnv("QUAK_SERVER", undefined);
+        const hosts = new Set<string>();
+        const fetch = (async (input: RequestInfo | URL, init?: RequestInit) => {
+            hosts.add(
+                new URL(input instanceof Request ? input.url : input).host,
+            );
+            return server(input, init);
+        }) as typeof globalThis.fetch;
+        const ctx: CliContext = {
+            ...context(),
+            login: (opts) =>
+                Client.login({
+                    ...opts,
+                    apiOptions: { ...opts.apiOptions, fetch },
+                }),
+            loadSession: (path) => loadSession(path, { fetch }),
+        };
+        const out = join(root, "photo.jpg");
+        try {
+            const opts = { server: "https://ente.example.com" };
+            expect(await loginCommand(ctx, opts)).toBe(0);
+            requests.length = 0;
+            expect(await getCommand(ctx, "200", { out })).toBe(0);
+        } finally {
+            vi.unstubAllEnvs();
+        }
+
+        const path = join(ctx.sessionDir, "session.json");
+        expect(JSON.parse(readFileSync(path, "utf-8")).apiOrigin).toBe(
+            "https://ente.example.com",
+        );
+        expect(readFileSync(out, "utf-8")).toBe("photo-2.jpg");
+        expect(requests.at(-1)).toBe("/files/download/200");
+        expect([...hosts]).toEqual(["ente.example.com"]);
+    });
+
     // `files` first fills the cache, so `get` waits for a refresh. No album has
     // changed since, so the refresh asks for no album's files.
     it("get on a cache that holds the account asks for no unchanged album's files, also for a photo in no album", async () => {

test/client/session.test.ts

@@ -47,6 +47,20 @@ describe("Client.toJSON", () => {
         expect(Client.fromJSON(snapshot).toJSON()).toEqual(snapshot);
     });
 
+    it("round-trips a snapshot that names a server", () => {
+        const snapshot = {
+            ...validSnapshot(),
+            apiOrigin: "https://ente.example.com",
+        };
+        expect(Client.fromJSON(snapshot).toJSON()).toEqual(snapshot);
+    });
+
+    it("names the server apiOptions gave fromJSON", () => {
+        const apiOrigin = "https://ente.example.com";
+        const client = Client.fromJSON(validSnapshot(), { apiOrigin });
+        expect(client.toJSON().apiOrigin).toBe(apiOrigin);
+    });
+
     it("throws instead of emitting a snapshot without a token", () => {
         const client = Client.fromJSON(validSnapshot());
         client.getApiClient().clearAuthToken();
@@ -77,6 +91,8 @@ describe("Client.fromJSON", () => {
         ["publicKey", undefined],
         ["publicKey", "not base64!"],
         ["publicKey", shortKey],
+        ["apiOrigin", 7],
+        ["apiOrigin", ""],
     ])("rejects %s = %j, naming the field", (field, value) => {
         const snapshot: Record<string, unknown> = { ...validSnapshot() };
         snapshot[field] = value;
@@ -85,6 +101,30 @@ describe("Client.fromJSON", () => {
         );
     });
 
+    // The token belongs to the snapshot's server, so that server wins over
+    // the one in `apiOptions`.
+    it("sends requests to the snapshot's server", async () => {
+        const urls: string[] = [];
+        const client = Client.fromJSON(
+            { ...validSnapshot(), apiOrigin: "https://ente.example.com/" },
+            {
+                apiOrigin: "https://other.example.com",
+                fetch: async (input) => {
+                    urls.push(String(input));
+                    return new Response(JSON.stringify({ collections: [] }), {
+                        status: 200,
+                        headers: { "content-type": "application/json" },
+                    });
+                },
+            },
+        );
+
+        await client.listCollections();
+        expect(urls).toEqual([
+            "https://ente.example.com/collections/v2?sinceTime=0",
+        ]);
+    });
+
     it.each([null, "a string", 42])("rejects a non-object %j", (value) => {
         expect(() => Client.fromJSON(value)).toThrow(
             /^Invalid session data: not a JSON object/,