const crypto = require('crypto');
 
 
function generateSalt(length) {
    return crypto.randomBytes(Math.ceil(length / 2)).toString('hex').slice(0, length);
}
 
function hash(password, salt) {
    const hash = crypto.createHmac('sha256', salt);
    hash.update(password);
    const hashedPassword = hash.digest('hex');
    return salt + hashedPassword; 
}
 
function compare(password, hashed) {
    const salt = hashed.substr(0, 16); 
    const hashedPassword = hash(password, salt); 
    return hashed === hashedPassword;
}
 

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