69 lines
1.3 KiB
JavaScript
69 lines
1.3 KiB
JavaScript
// Load modules
|
|
|
|
var Crypto = require('crypto');
|
|
var Boom = require('boom');
|
|
|
|
|
|
// Declare internals
|
|
|
|
var internals = {};
|
|
|
|
|
|
// Generate a cryptographically strong pseudo-random data
|
|
|
|
exports.randomString = function (size) {
|
|
|
|
var buffer = exports.randomBits((size + 1) * 6);
|
|
if (buffer instanceof Error) {
|
|
return buffer;
|
|
}
|
|
|
|
var string = buffer.toString('base64').replace(/\+/g, '-').replace(/\//g, '_').replace(/\=/g, '');
|
|
return string.slice(0, size);
|
|
};
|
|
|
|
|
|
exports.randomBits = function (bits) {
|
|
|
|
if (!bits ||
|
|
bits < 0) {
|
|
|
|
return Boom.internal('Invalid random bits count');
|
|
}
|
|
|
|
var bytes = Math.ceil(bits / 8);
|
|
try {
|
|
return Crypto.randomBytes(bytes);
|
|
}
|
|
catch (err) {
|
|
return Boom.internal('Failed generating random bits: ' + err.message);
|
|
}
|
|
};
|
|
|
|
|
|
// Compare two strings using fixed time algorithm (to prevent time-based analysis of MAC digest match)
|
|
|
|
exports.fixedTimeComparison = function (a, b) {
|
|
|
|
if (typeof a !== 'string' ||
|
|
typeof b !== 'string') {
|
|
|
|
return false;
|
|
}
|
|
|
|
var mismatch = (a.length === b.length ? 0 : 1);
|
|
if (mismatch) {
|
|
b = a;
|
|
}
|
|
|
|
for (var i = 0, il = a.length; i < il; ++i) {
|
|
var ac = a.charCodeAt(i);
|
|
var bc = b.charCodeAt(i);
|
|
mismatch |= (ac ^ bc);
|
|
}
|
|
|
|
return (mismatch === 0);
|
|
};
|
|
|
|
|