0
votes
0answers
37 views

Steps for creating a test environment where GUIDs are exploitable?

I have been using GUIDs as un-guessable tokens in various situations for some time. I came across this question/answer which seems to suggest that while this is ok in some situations, it should not ...
5
votes
3answers
895 views

CSRF Countermeasures

I'm working through a book on web application security and it says that an effective CSRF countermeasure is to assign a temporary pseudo-random token to sensitive actions performed by authenticated ...
10
votes
4answers
3k views

Generate cryptographically strong pseudorandom numbers in Javascript?

Is there any good way to generate cryptographically strong pseudorandom (or true random) numbers in Javascript? The crucial requirement: if a.com's Javascript generates some random numbers, no one ...
3
votes
2answers
1k views

Is this algorithm for a random string cryptographically secure?

I've pieced together this algorithm (if it can be called that) from various bits of code I've seen online, and I'm wondering how cryptographically secure it is. It's used to generate passwords: ...
70
votes
3answers
9k views

Is a rand from /dev/urandom secure for a login key?

Lets say I want to create a cookie for a user. Would simply generating a 1024 bit string by using /dev/urandom, and checking if it already exists (looping until I get a unique one) suffice? Or should ...
33
votes
5answers
5k views

Are GUIDs safe for one-time tokens?

I see a lot of sites use GUIDs for password resets, unsubscribe requests and other forms of unique identification. Presumably they are appealing because they are easy to generate, unique, ...