bcrypt – Page 2 – Tarik Billa

Can someone explain how BCrypt verifies a hash?

August 18, 2023 by Tarik

A BCrypt hash string looks like: $2a$10$Ro0CUfOqk6cXEKf3dyaM7OhSCvnwM9s4wIX9JeLapehKK5YdLxKcm \__/\/ \____________________/\_____________________________/ | | Salt Hash | Cost Version Where 2a: Algorithm Identifier (BCrypt, UTF8 encoded password, null terminated) 10: Cost Factor (210 = 1,024 rounds) Ro0CUfOqk6cXEKf3dyaM7O: OpenBSD-Base64 encoded salt (16 bytes ⇒ 22 characters) hSCvnwM9s4wIX9JeLapehKK5YdLxKcm: OpenBSD-Base64 encoded hash (24 bytes ⇒ 31 characters) Edit: i just noticed … Read more

Error installing bcrypt with pip on OS X: can’t find ffi.h (libffi is installed)

August 11, 2023 by Tarik

Without using sudo and CFLAGS and CPPFLAGS (unnecessary for pip): $ brew install pkg-config libffi $ export PKG_CONFIG_PATH=/usr/local/Cellar/libffi/3.0.13/lib/pkgconfig/ $ pip install bcrypt

How to compare plain text password to hashed password using bcrypt?

August 5, 2023 by Tarik

With py-bcrypt, you don’t need to store the salt separately: bcrypt stores the salt in the hash. You can simply use the hash as a salt, and the salt is stored in the beginning of the hash. >>> import bcrypt >>> salt = bcrypt.gensalt() >>> hashed = bcrypt.hashpw(‘secret’, salt) >>> hashed.find(salt) 0 >>> hashed == … Read more

NodeJS: bcrypt vs native crypto

June 29, 2023 by Tarik

Use bcrypt where you want to do slow and computationally expensive hashing — this will generally be for hashes where you really don’t want an attacker to be able to reverse the hash, e.g. user passwords. Use native crypto for everything else.

Hash Password in C#? Bcrypt/PBKDF2

June 13, 2023 by Tarik

PBKDF2 You were really close actually. The link you have given shows you how you can call the Rfc2898DeriveBytes function to get PBKDF2 hash results. However, you were thrown off by the fact that the example was using the derived key for encryption purposes (the original motivation for PBKDF1 and 2 was to create “key” … Read more

Why BCryptPasswordEncoder from Spring generate different outputs for same input?

June 12, 2023 by Tarik

public static void main(String[] args) { // spring 4.0.0 org.springframework.security.crypto.password.PasswordEncoder encoder = new org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder(); // $2a$10$lB6/PKg2/JC4XgdMDXyjs.dLC9jFNAuuNbFkL9udcXe/EBjxSyqxW // true // $2a$10$KbQiHKTa1WIsQFTQWQKCiujoTJJB7MCMSaSgG/imVkKRicMPwgN5i // true // $2a$10$5WfW4uxVb4SIdzcTJI9U7eU4ZwaocrvP.2CKkWJkBDKz1dmCh50J2 // true // $2a$10$0wR/6uaPxU7kGyUIsx/JS.krbAA9429fwsuCyTlEFJG54HgdR10nK // true // $2a$10$gfmnyiTlf8MDmwG7oqKJG.W8rrag8jt6dNW.31ukgr0.quwGujUuO // true for (int i = 0; i < 5; i++) { // “123456” – plain text – user input from user interface … Read more

Comparing BCrypt hash between PHP and NodeJS

June 6, 2023 by Tarik

This fails because the types of bcrypt hashes being generated from php and node are different. Laravel generates the $2y$ while node generates the $2a$. But the good news is the only difference between 2a and 2y are their prefixes. So what you can do is make one of the prefix similar to the other. … Read more

Bcrypt generates different hashes for the same input?

April 25, 2023 by Tarik

Jan is correct – bcrypt by design doesn’t generate the same hash for each input string. But there’s a way to check that a hashed password is valid, and it’s incorporated into the associated password encoder. So add a dependency injection for the passwordEncoder bean in your controller (def passwordEncoder) and change the lookup to … Read more

Rails: “BCrypt::Errors::InvalidHash” when trying to sign in

April 19, 2023 by Tarik

This means that the hash stored in password_digest is not a valid BCrypt hash (including if the field is empty). Based on the comments, it looks like you just created the user at a time the has_secure_password wasn’t there, so the password digest never got stored. Look in the database, you’ll probably see that password_digest … Read more

What’s the advantage of scrypt over bcrypt? [closed]

April 9, 2023 by Tarik

With scrypt in addition to increasing computation you can increase the amount of memory needed to compute the hash. This doesn’t bother software implementations much but is much harder to implement with hardware – which is what a dedicated attacker is likely to develop and use. bcrypt (and PBKDF2) use constant, and small, amounts of … Read more