diff options
Diffstat (limited to 'node_modules/follow-redirects/index.js')
-rw-r--r-- | node_modules/follow-redirects/index.js | 574 |
1 files changed, 574 insertions, 0 deletions
diff --git a/node_modules/follow-redirects/index.js b/node_modules/follow-redirects/index.js new file mode 100644 index 0000000..3f819d1 --- /dev/null +++ b/node_modules/follow-redirects/index.js @@ -0,0 +1,574 @@ +var url = require("url"); +var URL = url.URL; +var http = require("http"); +var https = require("https"); +var Writable = require("stream").Writable; +var assert = require("assert"); +var debug = require("./debug"); + +// Create handlers that pass events from native requests +var events = ["abort", "aborted", "connect", "error", "socket", "timeout"]; +var eventHandlers = Object.create(null); +events.forEach(function (event) { + eventHandlers[event] = function (arg1, arg2, arg3) { + this._redirectable.emit(event, arg1, arg2, arg3); + }; +}); + +// Error types with codes +var RedirectionError = createErrorType( + "ERR_FR_REDIRECTION_FAILURE", + "Redirected request failed" +); +var TooManyRedirectsError = createErrorType( + "ERR_FR_TOO_MANY_REDIRECTS", + "Maximum number of redirects exceeded" +); +var MaxBodyLengthExceededError = createErrorType( + "ERR_FR_MAX_BODY_LENGTH_EXCEEDED", + "Request body larger than maxBodyLength limit" +); +var WriteAfterEndError = createErrorType( + "ERR_STREAM_WRITE_AFTER_END", + "write after end" +); + +// An HTTP(S) request that can be redirected +function RedirectableRequest(options, responseCallback) { + // Initialize the request + Writable.call(this); + this._sanitizeOptions(options); + this._options = options; + this._ended = false; + this._ending = false; + this._redirectCount = 0; + this._redirects = []; + this._requestBodyLength = 0; + this._requestBodyBuffers = []; + + // Attach a callback if passed + if (responseCallback) { + this.on("response", responseCallback); + } + + // React to responses of native requests + var self = this; + this._onNativeResponse = function (response) { + self._processResponse(response); + }; + + // Perform the first request + this._performRequest(); +} +RedirectableRequest.prototype = Object.create(Writable.prototype); + +RedirectableRequest.prototype.abort = function () { + abortRequest(this._currentRequest); + this.emit("abort"); +}; + +// Writes buffered data to the current native request +RedirectableRequest.prototype.write = function (data, encoding, callback) { + // Writing is not allowed if end has been called + if (this._ending) { + throw new WriteAfterEndError(); + } + + // Validate input and shift parameters if necessary + if (!(typeof data === "string" || typeof data === "object" && ("length" in data))) { + throw new TypeError("data should be a string, Buffer or Uint8Array"); + } + if (typeof encoding === "function") { + callback = encoding; + encoding = null; + } + + // Ignore empty buffers, since writing them doesn't invoke the callback + // https://github.com/nodejs/node/issues/22066 + if (data.length === 0) { + if (callback) { + callback(); + } + return; + } + // Only write when we don't exceed the maximum body length + if (this._requestBodyLength + data.length <= this._options.maxBodyLength) { + this._requestBodyLength += data.length; + this._requestBodyBuffers.push({ data: data, encoding: encoding }); + this._currentRequest.write(data, encoding, callback); + } + // Error when we exceed the maximum body length + else { + this.emit("error", new MaxBodyLengthExceededError()); + this.abort(); + } +}; + +// Ends the current native request +RedirectableRequest.prototype.end = function (data, encoding, callback) { + // Shift parameters if necessary + if (typeof data === "function") { + callback = data; + data = encoding = null; + } + else if (typeof encoding === "function") { + callback = encoding; + encoding = null; + } + + // Write data if needed and end + if (!data) { + this._ended = this._ending = true; + this._currentRequest.end(null, null, callback); + } + else { + var self = this; + var currentRequest = this._currentRequest; + this.write(data, encoding, function () { + self._ended = true; + currentRequest.end(null, null, callback); + }); + this._ending = true; + } +}; + +// Sets a header value on the current native request +RedirectableRequest.prototype.setHeader = function (name, value) { + this._options.headers[name] = value; + this._currentRequest.setHeader(name, value); +}; + +// Clears a header value on the current native request +RedirectableRequest.prototype.removeHeader = function (name) { + delete this._options.headers[name]; + this._currentRequest.removeHeader(name); +}; + +// Global timeout for all underlying requests +RedirectableRequest.prototype.setTimeout = function (msecs, callback) { + var self = this; + + // Destroys the socket on timeout + function destroyOnTimeout(socket) { + socket.setTimeout(msecs); + socket.removeListener("timeout", socket.destroy); + socket.addListener("timeout", socket.destroy); + } + + // Sets up a timer to trigger a timeout event + function startTimer(socket) { + if (self._timeout) { + clearTimeout(self._timeout); + } + self._timeout = setTimeout(function () { + self.emit("timeout"); + clearTimer(); + }, msecs); + destroyOnTimeout(socket); + } + + // Stops a timeout from triggering + function clearTimer() { + // Clear the timeout + if (self._timeout) { + clearTimeout(self._timeout); + self._timeout = null; + } + + // Clean up all attached listeners + self.removeListener("abort", clearTimer); + self.removeListener("error", clearTimer); + self.removeListener("response", clearTimer); + if (callback) { + self.removeListener("timeout", callback); + } + if (!self.socket) { + self._currentRequest.removeListener("socket", startTimer); + } + } + + // Attach callback if passed + if (callback) { + this.on("timeout", callback); + } + + // Start the timer if or when the socket is opened + if (this.socket) { + startTimer(this.socket); + } + else { + this._currentRequest.once("socket", startTimer); + } + + // Clean up on events + this.on("socket", destroyOnTimeout); + this.on("abort", clearTimer); + this.on("error", clearTimer); + this.on("response", clearTimer); + + return this; +}; + +// Proxy all other public ClientRequest methods +[ + "flushHeaders", "getHeader", + "setNoDelay", "setSocketKeepAlive", +].forEach(function (method) { + RedirectableRequest.prototype[method] = function (a, b) { + return this._currentRequest[method](a, b); + }; +}); + +// Proxy all public ClientRequest properties +["aborted", "connection", "socket"].forEach(function (property) { + Object.defineProperty(RedirectableRequest.prototype, property, { + get: function () { return this._currentRequest[property]; }, + }); +}); + +RedirectableRequest.prototype._sanitizeOptions = function (options) { + // Ensure headers are always present + if (!options.headers) { + options.headers = {}; + } + + // Since http.request treats host as an alias of hostname, + // but the url module interprets host as hostname plus port, + // eliminate the host property to avoid confusion. + if (options.host) { + // Use hostname if set, because it has precedence + if (!options.hostname) { + options.hostname = options.host; + } + delete options.host; + } + + // Complete the URL object when necessary + if (!options.pathname && options.path) { + var searchPos = options.path.indexOf("?"); + if (searchPos < 0) { + options.pathname = options.path; + } + else { + options.pathname = options.path.substring(0, searchPos); + options.search = options.path.substring(searchPos); + } + } +}; + + +// Executes the next native request (initial or redirect) +RedirectableRequest.prototype._performRequest = function () { + // Load the native protocol + var protocol = this._options.protocol; + var nativeProtocol = this._options.nativeProtocols[protocol]; + if (!nativeProtocol) { + this.emit("error", new TypeError("Unsupported protocol " + protocol)); + return; + } + + // If specified, use the agent corresponding to the protocol + // (HTTP and HTTPS use different types of agents) + if (this._options.agents) { + var scheme = protocol.substr(0, protocol.length - 1); + this._options.agent = this._options.agents[scheme]; + } + + // Create the native request + var request = this._currentRequest = + nativeProtocol.request(this._options, this._onNativeResponse); + this._currentUrl = url.format(this._options); + + // Set up event handlers + request._redirectable = this; + for (var e = 0; e < events.length; e++) { + request.on(events[e], eventHandlers[events[e]]); + } + + // End a redirected request + // (The first request must be ended explicitly with RedirectableRequest#end) + if (this._isRedirect) { + // Write the request entity and end. + var i = 0; + var self = this; + var buffers = this._requestBodyBuffers; + (function writeNext(error) { + // Only write if this request has not been redirected yet + /* istanbul ignore else */ + if (request === self._currentRequest) { + // Report any write errors + /* istanbul ignore if */ + if (error) { + self.emit("error", error); + } + // Write the next buffer if there are still left + else if (i < buffers.length) { + var buffer = buffers[i++]; + /* istanbul ignore else */ + if (!request.finished) { + request.write(buffer.data, buffer.encoding, writeNext); + } + } + // End the request if `end` has been called on us + else if (self._ended) { + request.end(); + } + } + }()); + } +}; + +// Processes a response from the current native request +RedirectableRequest.prototype._processResponse = function (response) { + // Store the redirected response + var statusCode = response.statusCode; + if (this._options.trackRedirects) { + this._redirects.push({ + url: this._currentUrl, + headers: response.headers, + statusCode: statusCode, + }); + } + + // RFC7231§6.4: The 3xx (Redirection) class of status code indicates + // that further action needs to be taken by the user agent in order to + // fulfill the request. If a Location header field is provided, + // the user agent MAY automatically redirect its request to the URI + // referenced by the Location field value, + // even if the specific status code is not understood. + + // If the response is not a redirect; return it as-is + var location = response.headers.location; + if (!location || this._options.followRedirects === false || + statusCode < 300 || statusCode >= 400) { + response.responseUrl = this._currentUrl; + response.redirects = this._redirects; + this.emit("response", response); + + // Clean up + this._requestBodyBuffers = []; + return; + } + + // The response is a redirect, so abort the current request + abortRequest(this._currentRequest); + // Discard the remainder of the response to avoid waiting for data + response.destroy(); + + // RFC7231§6.4: A client SHOULD detect and intervene + // in cyclical redirections (i.e., "infinite" redirection loops). + if (++this._redirectCount > this._options.maxRedirects) { + this.emit("error", new TooManyRedirectsError()); + return; + } + + // RFC7231§6.4: Automatic redirection needs to done with + // care for methods not known to be safe, […] + // RFC7231§6.4.2–3: For historical reasons, a user agent MAY change + // the request method from POST to GET for the subsequent request. + if ((statusCode === 301 || statusCode === 302) && this._options.method === "POST" || + // RFC7231§6.4.4: The 303 (See Other) status code indicates that + // the server is redirecting the user agent to a different resource […] + // A user agent can perform a retrieval request targeting that URI + // (a GET or HEAD request if using HTTP) […] + (statusCode === 303) && !/^(?:GET|HEAD)$/.test(this._options.method)) { + this._options.method = "GET"; + // Drop a possible entity and headers related to it + this._requestBodyBuffers = []; + removeMatchingHeaders(/^content-/i, this._options.headers); + } + + // Drop the Host header, as the redirect might lead to a different host + var currentHostHeader = removeMatchingHeaders(/^host$/i, this._options.headers); + + // If the redirect is relative, carry over the host of the last request + var currentUrlParts = url.parse(this._currentUrl); + var currentHost = currentHostHeader || currentUrlParts.host; + var currentUrl = /^\w+:/.test(location) ? this._currentUrl : + url.format(Object.assign(currentUrlParts, { host: currentHost })); + + // Determine the URL of the redirection + var redirectUrl; + try { + redirectUrl = url.resolve(currentUrl, location); + } + catch (cause) { + this.emit("error", new RedirectionError(cause)); + return; + } + + // Create the redirected request + debug("redirecting to", redirectUrl); + this._isRedirect = true; + var redirectUrlParts = url.parse(redirectUrl); + Object.assign(this._options, redirectUrlParts); + + // Drop confidential headers when redirecting to a less secure protocol + // or to a different domain that is not a superdomain + if (redirectUrlParts.protocol !== currentUrlParts.protocol && + redirectUrlParts.protocol !== "https:" || + redirectUrlParts.host !== currentHost && + !isSubdomain(redirectUrlParts.host, currentHost)) { + removeMatchingHeaders(/^(?:authorization|cookie)$/i, this._options.headers); + } + + // Evaluate the beforeRedirect callback + if (typeof this._options.beforeRedirect === "function") { + var responseDetails = { headers: response.headers }; + try { + this._options.beforeRedirect.call(null, this._options, responseDetails); + } + catch (err) { + this.emit("error", err); + return; + } + this._sanitizeOptions(this._options); + } + + // Perform the redirected request + try { + this._performRequest(); + } + catch (cause) { + this.emit("error", new RedirectionError(cause)); + } +}; + +// Wraps the key/value object of protocols with redirect functionality +function wrap(protocols) { + // Default settings + var exports = { + maxRedirects: 21, + maxBodyLength: 10 * 1024 * 1024, + }; + + // Wrap each protocol + var nativeProtocols = {}; + Object.keys(protocols).forEach(function (scheme) { + var protocol = scheme + ":"; + var nativeProtocol = nativeProtocols[protocol] = protocols[scheme]; + var wrappedProtocol = exports[scheme] = Object.create(nativeProtocol); + + // Executes a request, following redirects + function request(input, options, callback) { + // Parse parameters + if (typeof input === "string") { + var urlStr = input; + try { + input = urlToOptions(new URL(urlStr)); + } + catch (err) { + /* istanbul ignore next */ + input = url.parse(urlStr); + } + } + else if (URL && (input instanceof URL)) { + input = urlToOptions(input); + } + else { + callback = options; + options = input; + input = { protocol: protocol }; + } + if (typeof options === "function") { + callback = options; + options = null; + } + + // Set defaults + options = Object.assign({ + maxRedirects: exports.maxRedirects, + maxBodyLength: exports.maxBodyLength, + }, input, options); + options.nativeProtocols = nativeProtocols; + + assert.equal(options.protocol, protocol, "protocol mismatch"); + debug("options", options); + return new RedirectableRequest(options, callback); + } + + // Executes a GET request, following redirects + function get(input, options, callback) { + var wrappedRequest = wrappedProtocol.request(input, options, callback); + wrappedRequest.end(); + return wrappedRequest; + } + + // Expose the properties on the wrapped protocol + Object.defineProperties(wrappedProtocol, { + request: { value: request, configurable: true, enumerable: true, writable: true }, + get: { value: get, configurable: true, enumerable: true, writable: true }, + }); + }); + return exports; +} + +/* istanbul ignore next */ +function noop() { /* empty */ } + +// from https://github.com/nodejs/node/blob/master/lib/internal/url.js +function urlToOptions(urlObject) { + var options = { + protocol: urlObject.protocol, + hostname: urlObject.hostname.startsWith("[") ? + /* istanbul ignore next */ + urlObject.hostname.slice(1, -1) : + urlObject.hostname, + hash: urlObject.hash, + search: urlObject.search, + pathname: urlObject.pathname, + path: urlObject.pathname + urlObject.search, + href: urlObject.href, + }; + if (urlObject.port !== "") { + options.port = Number(urlObject.port); + } + return options; +} + +function removeMatchingHeaders(regex, headers) { + var lastValue; + for (var header in headers) { + if (regex.test(header)) { + lastValue = headers[header]; + delete headers[header]; + } + } + return (lastValue === null || typeof lastValue === "undefined") ? + undefined : String(lastValue).trim(); +} + +function createErrorType(code, defaultMessage) { + function CustomError(cause) { + Error.captureStackTrace(this, this.constructor); + if (!cause) { + this.message = defaultMessage; + } + else { + this.message = defaultMessage + ": " + cause.message; + this.cause = cause; + } + } + CustomError.prototype = new Error(); + CustomError.prototype.constructor = CustomError; + CustomError.prototype.name = "Error [" + code + "]"; + CustomError.prototype.code = code; + return CustomError; +} + +function abortRequest(request) { + for (var e = 0; e < events.length; e++) { + request.removeListener(events[e], eventHandlers[events[e]]); + } + request.on("error", noop); + request.abort(); +} + +function isSubdomain(subdomain, domain) { + const dot = subdomain.length - domain.length - 1; + return dot > 0 && subdomain[dot] === "." && subdomain.endsWith(domain); +} + +// Exports +module.exports = wrap({ http: http, https: https }); +module.exports.wrap = wrap; |