117 lines
3.9 KiB
JavaScript
Executable file
117 lines
3.9 KiB
JavaScript
Executable file
/* jslint node: true */
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'use strict';
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var binding = require('../build/Release/sodium');
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var AuthKey = require('./keys/auth-key');
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var toBuffer = require('./toBuffer');
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var assert = require('assert');
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/**
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* Message Authentication
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*
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* Security model
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*
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* The crypto_auth function, viewed as a function of the message for a uniform
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* random key, is designed to meet the standard notion of unforgeability. This
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* means that an attacker cannot find authenticators for any messages not
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* authenticated by the sender, even if the attacker has adaptively influenced
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* the messages authenticated by the sender. For a formal definition see,
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* e.g., Section 2.4 of Bellare, Kilian, and Rogaway, "The security of the
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* cipher block chaining message authentication code," Journal of Computer and
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* System Sciences 61 (2000), 362–399;
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* http://www-cse.ucsd.edu/~mihir/papers/cbc.html.
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*
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* NaCl does not make any promises regarding "strong" unforgeability; perhaps
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* one valid authenticator can be converted into another valid authenticator
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* for the same message.
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* NaCl also does not make any promises regarding "truncated unforgeability."
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*
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* The secretKey *MUST* remain secret or an attacker could forge valid
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* authenticator tokens
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*
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* If key is not given a new random key is generated
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*
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* @param {String|Buffer|Array} [secretKey] A valid auth secret key
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* @constructor
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*/
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module.exports = function Auth(secretKey, encoding) {
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var self = this;
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/** default encoding to use in all string operations */
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self.defaultEncoding = undefined;
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// Init key
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self.secretKey = new AuthKey(secretKey, encoding);
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/** Size of the authentication token */
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self.bytes = function () {
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return binding.crypto_auth_BYTES;
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};
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/** String name of the default crypto primitive used in auth operations */
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self.primitive = function() {
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return binding.crypto_auth_PRIMITIVE;
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};
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/**
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* Get the auth-key secret key object
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* @returns {AuthKey|*}
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*/
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self.key = function() {
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return self.secretKey;
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};
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/**
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* Set the default encoding to use in all string conversions
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* @param {String} encoding encoding to use
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*/
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self.setEncoding = function(encoding) {
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assert(!!encoding.match(/^(?:utf8|ascii|binary|hex|utf16le|ucs2|base64)$/), 'Encoding ' + encoding + ' is currently unsupported.');
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self.defaultEncoding = encoding;
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};
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/**
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* Get the current default encoding
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* @returns {undefined|String}
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*/
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self.getEncoding = function() {
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return self.defaultEncoding;
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};
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/**
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* Generate authentication token for message, based on the secret key
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*
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* @param {string|Buffer|Array} message message to authenticate
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* @param {String} [encoding ] If v is a string you can specify the encoding
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*/
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self.generate = function(message, encoding) {
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if( !encoding && !self.defaultEncoding ) {
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throw new Error('Auth: please set enconding');
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}
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encoding = encoding || self.defaultEncoding;
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var messageBuf = toBuffer(message, encoding);
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return binding.crypto_auth(messageBuf, self.secretKey.get());
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};
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/**
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* Checks if the token authenticates the message
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*
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* @param {String|Buffer|Array} token message token
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* @param {String|Buffer|Array} message message to authenticate
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* @param {String} [encoding] If v is a string you can specify the encoding
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*/
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self.validate = function(token, message, encoding) {
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if(!self.secretKey) {
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throw new Error('Auth: no secret key found');
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}
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encoding = encoding || self.defaultEncoding;
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var tokenBuf = toBuffer(token, encoding);
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var messageBuf = toBuffer(message, encoding);
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return binding.crypto_auth_verify(tokenBuf, messageBuf, self.secretKey.get()) ? false : true;
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};
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};
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