csrf
v3.1.0
Published
primary logic behind csrf tokens
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CSRF
Logic behind CSRF token creation and verification.
Read Understanding-CSRF for more information on CSRF. Use this module to create custom CSRF middleware.
Looking for a CSRF framework for your favorite framework that uses this module?
- Express/connect: csurf or alt-xsrf
- Koa: koa-csrf or koa-atomic-session
Install
$ npm install csrf
TypeScript
This module includes a TypeScript declaration file to enable auto complete in compatible editors and type information for TypeScript projects.
API
var Tokens = require('csrf')
new Tokens([options])
Create a new token generation/verification instance. The options
argument is
optional and will just use all defaults if missing.
Options
Tokens accepts these properties in the options object.
saltLength
The length of the internal salt to use, in characters. Internally, the salt
is a base 62 string. Defaults to 8
characters.
secretLength
The length of the secret to generate, in bytes. Note that the secret is
passed around base-64 encoded and that this length refers to the underlying
bytes, not the length of the base-64 string. Defaults to 18
bytes.
tokens.create(secret)
Create a new CSRF token attached to the given secret
. The secret
is a
string, typically generated from the tokens.secret()
or tokens.secretSync()
methods. This token is what you should add into HTML <form>
blocks and
expect the user's browser to provide back.
var secret = tokens.secretSync()
var token = tokens.create(secret)
tokens.secret(callback)
Asynchronously create a new secret
, which is a string. The secret is to
be kept on the server, typically stored in a server-side session for the
user. The secret should be at least per user.
tokens.secret(function (err, secret) {
if (err) throw err
// do something with the secret
})
tokens.secret()
Asynchronously create a new secret
and return a Promise
. Please see
tokens.secret(callback)
documentation for full details.
Note: To use promises in Node.js prior to 0.12, promises must be
"polyfilled" using global.Promise = require('bluebird')
.
tokens.secret().then(function (secret) {
// do something with the secret
})
tokens.secretSync()
A synchronous version of tokens.secret(callback)
. Please see
tokens.secret(callback)
documentation for full details.
var secret = tokens.secretSync()
tokens.verify(secret, token)
Check whether a CSRF token is valid for the given secret
, returning
a Boolean.
if (!tokens.verify(secret, token)) {
throw new Error('invalid token!')
}