Does it matter what the salt is?

Question

I want to use a blowfish crypt() in php but I am scared that i will use a wrong salt. Is there something like a wrong salt? And is a salt that is for instance 2020352352 worse than salt that is lkfjaslj5l3k? I know you should put something random in it and I am planning on doing that.

Answer 1

Why reinvent the wheel?

Password_hash() uses a strong hash, generates a strong salt, and applies proper rounds automatically. password_hash() is a simple crypt() wrapper and compatible with existing password hashes. Use of password_hash() is encouraged. Source: Crypt - PHP Manual

If you want to use blowfish:

PASSWORD_BCRYPT - Use the CRYPT_BLOWFISH algorithm to create the hash.

The salt that you can pass through the (array) $options argument is optional, if omitted password_hash() will automatically create a salt. You can count on password_hash() coming up with a good enough salt, i.e. secure.