Files
Alta-Proxy-Tool/src/alta-client.js
T

252 lines
8.8 KiB
JavaScript

'use strict';
const { canonicalizeAltaOrigin, assertSameAltaOrigin } = require('./url-policy');
const { formatAltaError } = require('./error-redaction');
const DEFAULT_TIMEOUT_MS = 10_000;
const DEFAULT_MAX_RESPONSE_BYTES = 2 * 1024 * 1024;
const DEFAULT_MAX_REDIRECTS = 3;
const ENDPOINTS = Object.freeze({
getDevices: Object.freeze({ path: '/api/v1/devices', shape: 'array' }),
getDeviceSites: Object.freeze({ path: '/api/v1/deviceSites', shape: 'array' }),
getAuthInfo: Object.freeze({ path: '/api/v1/auth', shape: 'object' }),
});
const REDIRECT_STATUSES = new Set([301, 302, 303, 307, 308]);
function altaError(code, message, extra = {}) {
const error = new Error(message);
error.code = code;
Object.assign(error, extra);
return error;
}
async function axiosTransport(options) {
// Lazy loading keeps pure/injected transport tests independent of installed
// runtime dependencies while production still uses the pinned Axios package.
const axios = require('axios');
return axios.request({
method: options.method,
url: options.url,
headers: options.headers,
timeout: options.timeout,
signal: options.signal,
proxy: false,
maxRedirects: 0,
maxContentLength: options.maxResponseBytes,
maxBodyLength: 0,
responseType: 'arraybuffer',
validateStatus: () => true,
transitional: { clarifyTimeoutError: true },
});
}
function normalizeHeaders(headers) {
if (!headers || typeof headers !== 'object') return Object.freeze({});
const normalized = {};
for (const [key, value] of Object.entries(headers)) {
normalized[String(key).toLowerCase()] = Array.isArray(value) ? value[0] : value;
}
return Object.freeze(normalized);
}
function measuredData(data) {
if (Buffer.isBuffer(data) || data instanceof Uint8Array) {
return { bytes: data.byteLength, raw: Buffer.from(data).toString('utf8') };
}
if (typeof data === 'string') {
return { bytes: Buffer.byteLength(data), raw: data };
}
if (data === undefined) {
throw altaError('INVALID_ALTA_RESPONSE', 'Alta transport returned no response data');
}
try {
const raw = JSON.stringify(data);
if (raw === undefined) throw new Error('not serializable');
return { bytes: Buffer.byteLength(raw), value: data };
} catch {
throw altaError('INVALID_ALTA_RESPONSE_DATA', 'Alta response data is malformed');
}
}
function parseData(data, maxBytes) {
const measured = measuredData(data);
if (measured.bytes > maxBytes) {
throw altaError('ALTA_RESPONSE_TOO_LARGE', 'Alta response exceeded the size limit');
}
if (Object.prototype.hasOwnProperty.call(measured, 'value')) return measured.value;
try {
return JSON.parse(measured.raw);
} catch {
throw altaError('INVALID_ALTA_RESPONSE_DATA', 'Alta response was not valid JSON');
}
}
function enforceResponseSize(data, headers, maxBytes) {
const contentLength = headers['content-length'];
if (contentLength !== undefined) {
const parsedLength = Number(contentLength);
if (!Number.isSafeInteger(parsedLength) || parsedLength < 0) {
throw altaError('INVALID_ALTA_RESPONSE', 'Alta response had an invalid content length');
}
if (parsedLength > maxBytes) {
throw altaError('ALTA_RESPONSE_TOO_LARGE', 'Alta response exceeded the size limit');
}
}
if (data !== undefined && measuredData(data).bytes > maxBytes) {
throw altaError('ALTA_RESPONSE_TOO_LARGE', 'Alta response exceeded the size limit');
}
}
function safeTransportError(operation, error, cookie) {
const formatted = formatAltaError(operation, error, { secrets: [cookie, `va=${cookie}`] });
return altaError(formatted.code, formatted.message, {
status: formatted.status,
timeout: formatted.timeout,
});
}
class AltaClient {
constructor({
sessionStore,
transport = axiosTransport,
timeoutMs = DEFAULT_TIMEOUT_MS,
maxResponseBytes = DEFAULT_MAX_RESPONSE_BYTES,
maxRedirects = DEFAULT_MAX_REDIRECTS,
} = {}) {
if (!sessionStore || typeof sessionStore.requireSession !== 'function') {
throw new TypeError('AltaClient requires a session store');
}
if (typeof transport !== 'function') throw new TypeError('AltaClient transport must be a function');
if (!Number.isInteger(timeoutMs) || timeoutMs < 1 || timeoutMs > DEFAULT_TIMEOUT_MS) {
throw new RangeError('AltaClient timeout must be between 1 and 10000ms');
}
if (!Number.isInteger(maxResponseBytes) || maxResponseBytes < 1 || maxResponseBytes > DEFAULT_MAX_RESPONSE_BYTES) {
throw new RangeError('Invalid Alta response size limit');
}
if (!Number.isInteger(maxRedirects) || maxRedirects < 0 || maxRedirects > 5) {
throw new RangeError('Invalid Alta redirect limit');
}
this.sessionStore = sessionStore;
this.transport = transport;
this.timeoutMs = timeoutMs;
this.maxResponseBytes = maxResponseBytes;
this.maxRedirects = maxRedirects;
}
getDevices(...args) {
return this.#invoke('getDevices', args);
}
getDeviceSites(...args) {
return this.#invoke('getDeviceSites', args);
}
getAuthInfo(...args) {
return this.#invoke('getAuthInfo', args);
}
async #invoke(operation, args) {
if (args.length !== 0) {
throw altaError('INVALID_ALTA_ARGUMENTS', 'Alta API methods do not accept renderer parameters');
}
const endpoint = ENDPOINTS[operation];
const session = this.sessionStore.requireSession();
const origin = canonicalizeAltaOrigin(session.origin);
const cookie = session.cookie;
const deadline = Date.now() + this.timeoutMs;
const controller = new AbortController();
try {
const data = await this.#request(operation, `${origin}${endpoint.path}`, origin, cookie, deadline, controller, 0);
if (endpoint.shape === 'array' && !Array.isArray(data)) {
throw altaError('INVALID_ALTA_RESPONSE_DATA', 'Alta response did not contain an array');
}
if (endpoint.shape === 'object' && (!data || typeof data !== 'object' || Array.isArray(data))) {
throw altaError('INVALID_ALTA_RESPONSE_DATA', 'Alta response did not contain an object');
}
return data;
} catch (error) {
throw safeTransportError(operation, error, cookie);
} finally {
controller.abort();
}
}
async #request(operation, url, origin, cookie, deadline, controller, redirectCount) {
assertSameAltaOrigin(url, origin);
const remaining = deadline - Date.now();
if (remaining <= 0) throw altaError('ALTA_TIMEOUT', 'Alta request timed out', { timeout: true });
let timer;
const timeoutPromise = new Promise((_, reject) => {
timer = setTimeout(() => {
controller.abort();
reject(altaError('ALTA_TIMEOUT', 'Alta request timed out', { timeout: true }));
}, remaining);
});
let response;
try {
response = await Promise.race([
Promise.resolve(this.transport(Object.freeze({
method: 'GET',
url,
headers: Object.freeze({ Cookie: `va=${cookie}`, Accept: 'application/json' }),
timeout: remaining,
signal: controller.signal,
proxy: false,
maxRedirects: 0,
maxResponseBytes: this.maxResponseBytes,
}))),
timeoutPromise,
]);
} finally {
clearTimeout(timer);
}
if (!response || typeof response !== 'object' || !Number.isInteger(response.status)) {
throw altaError('INVALID_ALTA_RESPONSE', 'Alta transport returned an invalid response');
}
const headers = normalizeHeaders(response.headers);
// Bound every response, including redirects and errors, before acting on it.
enforceResponseSize(response.data, headers, this.maxResponseBytes);
if (REDIRECT_STATUSES.has(response.status)) {
if (typeof headers.location !== 'string' || headers.location.length === 0) {
throw altaError('UNSAFE_ALTA_REDIRECT', 'Alta redirect did not contain a safe location');
}
if (redirectCount >= this.maxRedirects) {
throw altaError('TOO_MANY_ALTA_REDIRECTS', 'Alta response exceeded the redirect limit');
}
let target;
try {
target = new URL(headers.location, url);
assertSameAltaOrigin(target.href, origin);
} catch {
throw altaError('UNSAFE_ALTA_REDIRECT', 'Alta redirect changed the validated origin');
}
return this.#request(operation, target.href, origin, cookie, deadline, controller, redirectCount + 1);
}
if (response.status < 200 || response.status > 299) {
throw altaError('ALTA_HTTP_ERROR', 'Alta request returned an error status', { status: response.status });
}
return parseData(response.data, this.maxResponseBytes);
}
}
function createAltaClient(options) {
return new AltaClient(options);
}
module.exports = {
AltaClient,
DEFAULT_MAX_REDIRECTS,
DEFAULT_MAX_RESPONSE_BYTES,
DEFAULT_TIMEOUT_MS,
ENDPOINTS,
axiosTransport,
createAltaClient,
};