/*!
* Connect - utils
* Copyright(c) 2010 Sencha Inc.
* Copyright(c) 2011 TJ Holowaychuk
* MIT Licensed
*/
/**
* Module dependencies.
*/
var http = require('http')
, crypto = require('crypto')
, parse = require('url').parse
, signature = require('cookie-signature');
/**
* Extract the mime type from the given request's
* _Content-Type_ header.
*
* @param {IncomingMessage} req
* @return {String}
* @api private
*/
exports.mime = function(req) {
var str = req.headers['content-type'] || '';
return str.split(';')[0];
};
/**
* Generate an `Error` from the given status `code`
* and optional `msg`.
*
* @param {Number} code
* @param {String} msg
* @return {Error}
* @api private
*/
exports.error = function(code, msg){
var err = new Error(msg || http.STATUS_CODES[code]);
err.status = code;
return err;
};
/**
* Return md5 hash of the given string and optional encoding,
* defaulting to hex.
*
* utils.md5('wahoo');
* // => "e493298061761236c96b02ea6aa8a2ad"
*
* @param {String} str
* @param {String} encoding
* @return {String}
* @api private
*/
exports.md5 = function(str, encoding){
return crypto
.createHash('md5')
.update(str)
.digest(encoding || 'hex');
};
/**
* Merge object b with object a.
*
* var a = { foo: 'bar' }
* , b = { bar: 'baz' };
*
* utils.merge(a, b);
* // => { foo: 'bar', bar: 'baz' }
*
* @param {Object} a
* @param {Object} b
* @return {Object}
* @api private
*/
exports.merge = function(a, b){
if (a && b) {
for (var key in b) {
a[key] = b[key];
}
}
return a;
};
/**
* Escape the given string of `html`.
*
* @param {String} html
* @return {String}
* @api private
*/
exports.escape = function(html){
return String(html)
.replace(/&(?!\w+;)/g, '&')
.replace(/</g, '<')
.replace(/>/g, '>')
.replace(/"/g, '"');
};
/**
* Return a unique identifier with the given `len`.
*
* utils.uid(10);
* // => "FDaS435D2z"
*
* @param {Number} len
* @return {String}
* @api private
*/
exports.uid = function(len) {
return crypto.randomBytes(Math.ceil(len * 3 / 4))
.toString('base64')
.slice(0, len);
};
/**
* Sign the given `val` with `secret`.
*
* @param {String} val
* @param {String} secret
* @return {String}
* @api private
*/
exports.sign = function(val, secret){
console.warn('do not use utils.sign(), use https://github.com/visionmedia/node-cookie-signature')
return val + '.' + crypto
.createHmac('sha256', secret)
.update(val)
.digest('base64')
.replace(/=+$/, '');
};
/**
* Unsign and decode the given `val` with `secret`,
* returning `false` if the signature is invalid.
*
* @param {String} val
* @param {String} secret
* @return {String|Boolean}
* @api private
*/
exports.unsign = function(val, secret){
console.warn('do not use utils.unsign(), use https://github.com/visionmedia/node-cookie-signature')
var str = val.slice(0, val.lastIndexOf('.'));
return exports.sign(str, secret) == val
? str
: false;
};
/**
* Parse signed cookies, returning an object
* containing the decoded key/value pairs,
* while removing the signed key from `obj`.
*
* @param {Object} obj
* @return {Object}
* @api private
*/
exports.parseSignedCookies = function(obj, secret){
var ret = {};
Object.keys(obj).forEach(function(key){
var val = obj[key];
if (0 == val.indexOf('s:')) {
val = signature.unsign(val.slice(2), secret);
if (val) {
ret[key] = val;
delete obj[key];
}
}
});
return ret;
};
/**
* Parse a signed cookie string, return the decoded value
*
* @param {String} str signed cookie string
* @param {String} secret
* @return {String} decoded value
* @api private
*/
exports.parseSignedCookie = function(str, secret){
return 0 == str.indexOf('s:')
? signature.unsign(str.slice(2), secret)
: str;
};
/**
* Parse JSON cookies.
*
* @param {Object} obj
* @return {Object}
* @api private
*/
exports.parseJSONCookies = function(obj){
Object.keys(obj).forEach(function(key){
var val = obj[key];
var res = exports.parseJSONCookie(val);
if (res) obj[key] = res;
});
return obj;
};
/**
* Parse JSON cookie string
*
* @param {String} str
* @return {Object} Parsed object or null if not json cookie
* @api private
*/
exports.parseJSONCookie = function(str) {
if (0 == str.indexOf('j:')) {
try {
return JSON.parse(str.slice(2));
} catch (err) {
// no op
}
}
};
/**
* Pause `data` and `end` events on the given `obj`.
* Middleware performing async tasks _should_ utilize
* this utility (or similar), to re-emit data once
* the async operation has completed, otherwise these
* events may be lost.
*
* var pause = utils.pause(req);
* fs.readFile(path, function(){
* next();
* pause.resume();
* });
*
* @param {Object} obj
* @return {Object}
* @api private
*/
exports.pause = require('pause');
/**
* Strip `Content-*` headers from `res`.
*
* @param {ServerResponse} res
* @api private
*/
exports.removeContentHeaders = function(res){
Object.keys(res._headers).forEach(function(field){
if (0 == field.indexOf('content')) {
res.removeHeader(field);
}
});
};
/**
* Check if `req` is a conditional GET request.
*
* @param {IncomingMessage} req
* @return {Boolean}
* @api private
*/
exports.conditionalGET = function(req) {
return req.headers['if-modified-since']
|| req.headers['if-none-match'];
};
/**
* Respond with 401 "Unauthorized".
*
* @param {ServerResponse} res
* @param {String} realm
* @api private
*/
exports.unauthorized = function(res, realm) {
res.statusCode = 401;
res.setHeader('WWW-Authenticate', 'Basic realm="' + realm + '"');
res.end('Unauthorized');
};
/**
* Respond with 304 "Not Modified".
*
* @param {ServerResponse} res
* @param {Object} headers
* @api private
*/
exports.notModified = function(res) {
exports.removeContentHeaders(res);
res.statusCode = 304;
res.end();
};
/**
* Return an ETag in the form of `"<size>-<mtime>"`
* from the given `stat`.
*
* @param {Object} stat
* @return {String}
* @api private
*/
exports.etag = function(stat) {
return '"' + stat.size + '-' + Number(stat.mtime) + '"';
};
/**
* Parse the given Cache-Control `str`.
*
* @param {String} str
* @return {Object}
* @api private
*/
exports.parseCacheControl = function(str){
var directives = str.split(',')
, obj = {};
for(var i = 0, len = directives.length; i < len; i++) {
var parts = directives[i].split('=')
, key = parts.shift().trim()
, val = parseInt(parts.shift(), 10);
obj[key] = isNaN(val) ? true : val;
}
return obj;
};
/**
* Parse the `req` url with memoization.
*
* @param {ServerRequest} req
* @return {Object}
* @api private
*/
exports.parseUrl = function(req){
var parsed = req._parsedUrl;
if (parsed && parsed.href == req.url) {
return parsed;
} else {
return req._parsedUrl = parse(req.url);
}
};
/**
* Parse byte `size` string.
*
* @param {String} size
* @return {Number}
* @api private
*/
exports.parseBytes = require('bytes');
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