检查Cookie是否设置了安全标记并仅使用JavaScript更新

Question

My issue is we set some cookies, using JS, with a 1 year expiration and that particular cookie didn't have the secure flag set. We now want to update the cookies to have the secure flag set. The code that creates the cookies now has the "secure" attribute and all new cookies have the "secure" flag. The issue is how do I update existing cookies? I'm assuming I have to destroy the cookie and then recreate it with the secure flag set? I don't know if there is any other way to do this? Also is there a way using JavaScript to detect if the cookie does have the flag set before deleting it?

Thanks!

Answer 1

You can't check cookies flags with pure JavaScript. If you want to add flag, just create a new one cookie and browser will overwrite old.

Example:

Type in console:

const year = 60*60*24*365;
document.cookie = 'mytestcookie=1;max-age='+year;

And look into cookies tab in your browser developer tools. You will see it's insecure. Now, type:

document.cookie = 'mytestcookie=2;max-age='+year+';secure';

Look again.