diff options
Diffstat (limited to 'app/models/session.rb')
| -rw-r--r-- | app/models/session.rb | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/app/models/session.rb b/app/models/session.rb index a5fd26e..f5e642b 100644 --- a/app/models/session.rb +++ b/app/models/session.rb @@ -1,3 +1,42 @@ class Session < ActiveRecord::Base belongs_to :user + + ## + # Create a random remember token for the user. This will be + # changed every time the user creates a new session. + # + # If you want this value, hang on to it; the raw value is + # discarded afterward. + # + # By changing the cookie every new session, any hijacked sessions + # (where the attacker steals a cookie to sign in as a certain + # user) will expire the next time the user signs back in. + # + # The random string is of length 16 composed of A-Z, a-z, 0-9 + # This is the browser's cookie value. + def create_token() + t = SecureRandom.urlsafe_base64 + self.token = Session.hash_token(t) + t + end + + ## + # Encrypt the remember token. + # This is the encrypted version of the cookie stored on + # the database. + # + # The reasoning for storing a hashed token is so that even if + # the database is compromised, the attacker won't be able to use + # the remember tokens to sign in. + def Session.hash_token(token) + # SHA-1 (Secure Hash Algorithm) is a US engineered hash + # function that produces a 20 byte hash value which typically + # forms a hexadecimal number 40 digits long. + # The reason I am not using the Bcrypt algorithm is because + # SHA-1 is much faster and I will be calling this on + # every page a user accesses. + # + # https://en.wikipedia.org/wiki/SHA-1 + Digest::SHA1.hexdigest(token.to_s) + end end |