Hashing password module

var crypto = require('crypto');

module.exports = {
    algorithm: 'sha256',
    repetitions: 65536,
    generateHash: function(value){
        var v = crypto.createHash(this.algorithm);
        v.update(value);
        return v.digest();
    },
    checkPassword: function(password, input){
        return password === this.hashPassword(input, password.substr(0, password.length/2));
    },
    hashPassword: function(password, salt){
        var repetitions = this.repetitions;
        salt = salt || this.generateHash(crypto.randomBytes(16));
        hash = this.generateHash (salt + password);
        while (repetitions--)
            hash = this.generateHash(hash + repetitions + salt + password);
        return salt + hash;
    }
};