= Rodauth

Rodauth is an authentication and account management framework for
rack applications.  It's built using Roda and Sequel, but it can
be used with other web frameworks, database libraries, and databases.
When used with PostgreSQL, MySQL, and Microsoft SQL Server in the
default configuration, it offers additional security for password
hashes by protecting access via database functions.

== Design Goals

* Security: Ship in a maximum security by default configuration
* Simplicity: Allow for easy configuration via a DSL
* Flexibility: Allow for easy overriding of any part of the framework

== Features

* Login
* Logout
* Change Password
* Change Login
* Reset Password
* Create Account
* Close Account
* Verify Account
* Confirm Password
* Remember (Autologin via token)
* Lockout (Bruteforce protection)
* Email Authentication (Login via email link)
* OTP (2 factor authentication via TOTP)
* Recovery Codes (2 factor authentication via backup codes)
* SMS Codes (2 factor authentication via SMS)
* Verify Login Change (Verify new login before changing login)
* Verify Account Grace Period (Don't require verification before login)
* Password Grace Period (Don't require password entry if recently entered)
* Password Complexity (More sophisticated checks)
* Disallow Password Reuse
* Disallow Common Passwords
* Password Expiration
* Account Expiration
* Session Expiration
* Single Session (Only one active session per account)
* JWT (JSON API support for all other features)
* JWT Refresh (Access & Refresh Token)
* Update Password Hash (when hash cost changes)
* HTTP Basic Auth
* Change Password Notify

== Resources

Website :: http://rodauth.jeremyevans.net
Demo Site :: http://rodauth-demo.jeremyevans.net
Source :: http://github.com/jeremyevans/rodauth
Bugs :: http://github.com/jeremyevans/rodauth/issues
Google Group :: https://groups.google.com/forum/#!forum/rodauth
IRC :: irc://chat.freenode.net/#rodauth

== Dependencies

There are some dependencies that Rodauth uses by default, but are
development dependencies instead of runtime dependencies in the
gem as it is possible to run without them:

tilt :: Used by all features unless in JSON API only mode.
rack_csrf :: Used by all features unless in JSON API only mode
             or the :csrf=>false|:route_csrf option is used when
             loading the Rodauth plugin.
bcrypt :: Used by default for password matching, can be skipped
          if password_match? is overridden for custom authentication.
mail :: Used by default for mailing in the reset password, verify
        account, verify_login_change, change_password_notify, and
        lockout features.
rotp, rqrcode :: Used by the otp feature
jwt :: Used by the jwt feature

== Security

=== Password Hash Access Via Database Functions

By default on PostgreSQL, MySQL, and Microsoft SQL Server, Rodauth
uses database functions to access password hashes, with the user
running the application unable to get direct access to password
hashes.  This reduces the risk of an attacker being able to access
password hashes and use them to attack other sites.

The rest of this section describes this feature in more detail, but
note that Rodauth does not require this feature be used and works
correctly without it.  There may be cases where you cannot use
this feature, such as when using a different database or when you
do not have full control over the database you are using.

Passwords are hashed using bcrypt, and the password hashes are
kept in a separate table from the accounts table, with a foreign key
referencing the accounts table.  Two database functions are added,
one to retrieve the salt for a password, and the other to check
if a given password hash matches the password hash for the user.

Two database accounts are used. The first is the account that the
application uses, which is referred to as the +app+ account. The +app+
account does not have access to read the password hashes. The other
account handles password hashes and is referred to as the +ph+
account.  The +ph+ account sets up the database functions that can
retrieve the salt for a given account's password, and check if a
password hash matches for a given account.  The +ph+ account
sets these functions up so that the +app+ account can execute the
functions using the +ph+ account's permissions.  This allows the
+app+ account to check passwords without having access to read
password hashes.

While the +app+ account is not be able to read password hashes, it
is still be able to insert password hashes, update passwords hashes,
and delete password hashes, so the additional security is not that
painful.

By disallowing the +app+ account access to the password hashes,
it is much more difficult for an attacker to access the password
hashes, even if they are able to exploit an SQL injection or remote
code execution vulnerability in the application.

The reason for extra security in regards to password hashes stems from
the fact that people tend to choose poor passwords and reuse passwords,
so a compromise of one database containing password hashes can result
in account access on other sites, making password hash storage of
critical importance even if the other data stored is not that important.

If you are storing other sensitive information in your database, you
should consider using a similar approach in other areas (or all areas)
of your application.

=== Tokens

Account verification, password resets, email auth, verify login change,
remember, and lockout tokens all use a similar approach.  They all
provide a token, in the format "account-id_long-random-string".  By
including the id of the account in the token, an attacker can only
attempt to bruteforce the token for a single account, instead of being
able to bruteforce tokens for all accounts at once (which would be
possible if the token was just a random string).

Additionally, all comparisons of tokens use a timing-safe comparison
function to reduce the risk of timing attacks.

== HMAC

By default, Rodauth does not use HMACs, but you are encouraged to use
the +hmac_secret+ configuration method to set an HMAC secret.  Setting
an HMAC secret will enable HMACs for additional security, as described
below.

=== email_base feature

All features that send email use this feature.  Setting +hmac_secret+
will make the tokens sent via email use an HMAC, while the raw token
stored in the database will not use an HMAC.  This will make it so
if the tokens in the database are leaked (e.g. via an SQL injection
vulnerability), they will not be usable without also having access
to the +hmac_secret+.  Without an HMAC, the raw token is sent in the
email, and if the tokens in the database are leaked, they will be
usable.

To allow for an graceful transition, you can set +allow_raw_email_token?+
to true temporarily.  This will allow the raw tokens in previous sent
emails to still work.  This should only be set temporarily as it
removes the security that +hmac_secret+ adds.  Most features that
send email have tokens that expire by default in 1 day.  The
exception is the verify_account feature, which has tokens that do
not expire.  For the verify_account feature, if the user requested
an email before +hmac_secret+ was set, after +allow_raw_email_token+
is no longer set, they will need to request the verification email
be resent, in which case they will receive an email with a token
that uses an HMAC.

=== remember feature

Similar to the email_base feature, this uses HMACs for remember
tokens, while storing the raw tokens in the database.  This makes
it so if the raw tokens in the database are leaked, the remember
tokens are not usable without knowledge of the +hmac_secret+.

The +raw_remember_token_deadline+ configuration method can
be set to allow a previously set raw remember token to be used
if the deadline for the remember token is before the given time.
This allows for graceful transition to using HMACs for remember tokens.
By default, the deadline is 14 days after the token is created, so this
should be set to 14 days after the time you enable the HMAC for the
remember feature if you are using the defaults.

=== otp feature

Setting +hmac_secret+ will provide HMACed OTP keys to users, and
would store the raw OTP keys in the database.  This will make so
if the raw OTP keys in the database are leaked, they will not be
usable for two factor authentication without knowledge of the +hmac_secret+.

Unfortunately, there can be no simple graceful transition for existing users.
When introducing +hmac_secret+ to a Rodauth installation that already uses
the otp feature, you will have to either revoke and replace all OTP keys,
set +otp_keys_use_hmac?+ to false and continue to use raw OTP keys, or override
+otp_keys_use_hmac?+ to return false if the user was issued an OTP key before
+hmac_secret+ was added to the configuration, and true otherwise.
+otp_keys_use_hmac?+ defaults to true if +hmac_secret+ is set, and false
otherwise.

If +otp_keys_use_hmac?+ is true, Rodauth will also ensure during OTP setup
that the OTP key was generated by the server.  If +otp_keys_use_hmac?+ is false,
any OTP key in a valid format will be accepted during setup.

If +otp_keys_use_hmac?+ is true, the jwt and otp features are in use and you
are setting up OTP via JSON requests, you need to first send a POST request
to the OTP setup route.  This will return an error with the +otp_secret+ and
+otp_raw_secret+ parameters in the JSON.  These parameters should be submitted
in the POST request to setup OTP, along with a valid OTP auth code for the
+otp_secret+.

=== single_session feature

Setting +hmac_secret+ will ensure the single session secret set in the
session will be an HMACed.  This does not affect security, as the session
itself should at the least by protected by an HMAC (if not encrypted).
This is only done for consistency, so that the raw tokens in the database
are distinct from the tokens provided to the users.  To allow for a
graceful transition, +allow_raw_single_session_key?+ can be set to true.

== PostgreSQL Database Setup

In order to get full advantages of Rodauth's security design on PostgreSQL,
multiple database accounts are involved:

1. database superuser account (usually postgres)
2. +app+ account (same name as application)
3. +ph+ account (application name with +_password+ appended)

The database superuser account is used to load extensions related to the
database.  The application should never be run using the database
superuser account.

=== Create database accounts

If you are currently running your application using the database superuser
account, the first thing you need to do is to create the +app+ database
account.  It's often best to name this account the same as the
database name.

You should also create the +ph+ database account which will handle access
to the password hashes.

Example for PostgreSQL:

  createuser -U postgres ${DATABASE_NAME}
  createuser -U postgres ${DATABASE_NAME}_password

Note that if the database superuser account owns all of the items in the
database, you'll need to change the ownership to the database account you
just created.  See https://gist.github.com/jeremyevans/8483320
for a way to do that.

=== Create database

In general, the +app+ account is the owner of the database, since it will
own most of the tables:

  createdb -U postgres -O ${DATABASE_NAME} ${DATABASE_NAME}

Note that this is not the most secure way to develop applications.  For
maximum security, you would want to use a separate database account as
the owner of the tables, have the +app+ account not be the
owner of any tables, and specifically grant the +app+ account only the
minimum access it needs to work correctly.  Doing that is beyond the
scope of Rodauth, though.

=== Load extensions

If you want to use the login features for Rodauth, you need to load the
citext extension if you want to support case insensitive logins.

Example:

  psql -U postgres -c "CREATE EXTENSION citext" ${DATABASE_NAME}

Note that on Heroku, this extension can be loaded using a standard database
account.  If you want logins to be case sensitive (generally considered a
bad idea), you don't need to use the PostgreSQL citext extension. Just
remember to modify the migration below to use +String+ instead of +citext+
for the email in that case.

=== Using non-default schema

PostgreSQL sets up new tables in the public schema by default.
If you would like to use separate schemas per user, you can do:

  psql -U postgres -c "DROP SCHEMA public;" ${DATABASE_NAME}
  psql -U postgres -c "CREATE SCHEMA ${DATABASE_NAME} AUTHORIZATION ${DATABASE_NAME};" ${DATABASE_NAME}
  psql -U postgres -c "CREATE SCHEMA ${DATABASE_NAME}_password AUTHORIZATION ${DATABASE_NAME}_password;" ${DATABASE_NAME}
  psql -U postgres -c "GRANT USAGE ON SCHEMA ${DATABASE_NAME} TO ${DATABASE_NAME}_password;" ${DATABASE_NAME}
  psql -U postgres -c "GRANT USAGE ON SCHEMA ${DATABASE_NAME}_password TO ${DATABASE_NAME};" ${DATABASE_NAME}

You'll need to modify the code to load the extension to specify the schema:

  psql -U postgres -c "CREATE EXTENSION citext SCHEMA ${DATABASE_NAME}" ${DATABASE_NAME}

When running the migration for the +ph+ user you'll need to modify a couple
things for the schema changes:

  create_table(:account_password_hashes) do
    foreign_key :id, Sequel[:${DATABASE_NAME}][:accounts], :primary_key=>true, :type=>:Bignum
    String :password_hash, :null=>false
  end
  Rodauth.create_database_authentication_functions(self, :table_name=>"${DATABASE_NAME}_password.account_password_hashes")

  # if using the disallow_password_reuse feature:
  create_table(:account_previous_password_hashes) do
    primary_key :id, :type=>:Bignum
    foreign_key :account_id, Sequel[:${DATABASE_NAME}][:accounts], :type=>:Bignum
    String :password_hash, :null=>false
  end
  Rodauth.create_database_previous_password_check_functions(self, :table_name=>"${DATABASE_NAME}_password.account_previous_password_hashes")

You'll also need to use the following Rodauth configuration methods so that the
app account calls functions in a separate schema:

  function_name do |name|
    "${DATABASE_NAME}_password.#{name}"
  end
  password_hash_table Sequel[:${DATABASE_NAME}_password][:account_password_hashes]

  # if using the disallow_password_reuse feature:
  previous_password_hash_table Sequel[:${DATABASE_NAME}_password][:account_previous_password_hashes]

== MySQL Database Setup

MySQL does not have the concept of object owners, and MySQL's GRANT/REVOKE
support is much more limited than PostgreSQL's. When using MySQL, it is
recommended to GRANT the +ph+ account ALL privileges on the database,
including the ability to GRANT permissions to the +app+ account:

  CREATE USER '${DATABASE_NAME}'@'localhost' IDENTIFIED BY '${PASSWORD}';
  CREATE USER '${DATABASE_NAME}_password'@'localhost' IDENTIFIED BY '${OTHER_PASSWORD}';
  GRANT ALL ON ${DATABASE_NAME}.* TO '${DATABASE_NAME}_password'@'localhost' WITH GRANT OPTION;

You should run all migrations as the +ph+ account, and GRANT specific access
to the +app+ account as needed.

Adding the database functions on MySQL may require setting the 
<tt>log_bin_trust_function_creators=1</tt> setting in the MySQL configuration.

== Microsoft SQL Server Database Setup

Microsoft SQL Server has a concept of database owners, but similar to MySQL
usage it's recommended to use the +ph+ account as the superuser for the
database, and have it GRANT permissions to the +app+ account:

  CREATE LOGIN rodauth_test WITH PASSWORD = 'rodauth_test';
  CREATE LOGIN rodauth_test_password WITH PASSWORD = 'rodauth_test';
  CREATE DATABASE rodauth_test;
  USE rodauth_test;
  CREATE USER rodauth_test FOR LOGIN rodauth_test;
  GRANT CONNECT, EXECUTE TO rodauth_test;
  EXECUTE sp_changedbowner 'rodauth_test_password';

You should run all migrations as the +ph+ account, and GRANT specific access
to the +app+ account as needed.

== Creating tables

Because two different database accounts are used, two different migrations
are required, one for each database account.  Here are example migrations.
You can modify them to add support for additional columns, or remove tables
or columns related to features that you don't need.

First migration.  On PostgreSQL, this should be run with the +app+ account,
on MySQL and Microsoft SQL Server this should be run with the +ph+ account.

Note that these migrations require Sequel 4.35.0+.

  Sequel.migration do
    up do
      extension :date_arithmetic

      # Used by the account verification and close account features
      create_table(:account_statuses) do
        Integer :id, :primary_key=>true
        String :name, :null=>false, :unique=>true
      end
      from(:account_statuses).import([:id, :name], [[1, 'Unverified'], [2, 'Verified'], [3, 'Closed']])

      db = self
      create_table(:accounts) do
        primary_key :id, :type=>:Bignum
        foreign_key :status_id, :account_statuses, :null=>false, :default=>1
        if db.database_type == :postgres
          citext :email, :null=>false
          constraint :valid_email, :email=>/^[^,;@ \r\n]+@[^,@; \r\n]+\.[^,@; \r\n]+$/
          index :email, :unique=>true, :where=>{:status_id=>[1, 2]}
        else
          String :email, :null=>false
          index :email, :unique=>true
        end
      end

      deadline_opts = proc do |days|
        if database_type == :mysql
          {:null=>false}
        else
          {:null=>false, :default=>Sequel.date_add(Sequel::CURRENT_TIMESTAMP, :days=>days)}
        end
      end

      # Used by the password reset feature
      create_table(:account_password_reset_keys) do
        foreign_key :id, :accounts, :primary_key=>true, :type=>:Bignum
        String :key, :null=>false
        DateTime :deadline, deadline_opts[1]
        DateTime :email_last_sent, :null=>false, :default=>Sequel::CURRENT_TIMESTAMP
      end

      # Used by the jwt refresh feature
      create_table(:account_jwt_refresh_keys) do
        primary_key :id, :type=>:Bignum
        foreign_key :account_id, :accounts, :type=>:Bignum
        String :key, :null=>false
        DateTime :deadline, deadline_opts[1]
      end

      # Used by the account verification feature
      create_table(:account_verification_keys) do
        foreign_key :id, :accounts, :primary_key=>true, :type=>:Bignum
        String :key, :null=>false
        DateTime :requested_at, :null=>false, :default=>Sequel::CURRENT_TIMESTAMP
        DateTime :email_last_sent, :null=>false, :default=>Sequel::CURRENT_TIMESTAMP
      end

      # Used by the verify login change feature
      create_table(:account_login_change_keys) do
        foreign_key :id, :accounts, :primary_key=>true, :type=>:Bignum
        String :key, :null=>false
        String :login, :null=>false
        DateTime :deadline, deadline_opts[1]
      end

      # Used by the remember me feature
      create_table(:account_remember_keys) do
        foreign_key :id, :accounts, :primary_key=>true, :type=>:Bignum
        String :key, :null=>false
        DateTime :deadline, deadline_opts[14]
      end

      # Used by the lockout feature
      create_table(:account_login_failures) do
        foreign_key :id, :accounts, :primary_key=>true, :type=>:Bignum
        Integer :number, :null=>false, :default=>1
      end
      create_table(:account_lockouts) do
        foreign_key :id, :accounts, :primary_key=>true, :type=>:Bignum
        String :key, :null=>false
        DateTime :deadline, deadline_opts[1]
        DateTime :email_last_sent
      end

      # Used by the email auth feature
      create_table(:account_email_auth_keys) do
        foreign_key :id, :accounts, :primary_key=>true, :type=>:Bignum
        String :key, :null=>false
        DateTime :deadline, deadline_opts[1]
        DateTime :email_last_sent, :null=>false, :default=>Sequel::CURRENT_TIMESTAMP
      end

      # Used by the password expiration feature
      create_table(:account_password_change_times) do
        foreign_key :id, :accounts, :primary_key=>true, :type=>:Bignum
        DateTime :changed_at, :null=>false, :default=>Sequel::CURRENT_TIMESTAMP
      end

      # Used by the account expiration feature
      create_table(:account_activity_times) do
        foreign_key :id, :accounts, :primary_key=>true, :type=>:Bignum
        DateTime :last_activity_at, :null=>false
        DateTime :last_login_at, :null=>false
        DateTime :expired_at
      end

      # Used by the single session feature
      create_table(:account_session_keys) do
        foreign_key :id, :accounts, :primary_key=>true, :type=>:Bignum
        String :key, :null=>false
      end

      # Used by the otp feature
      create_table(:account_otp_keys) do
        foreign_key :id, :accounts, :primary_key=>true, :type=>:Bignum
        String :key, :null=>false
        Integer :num_failures, :null=>false, :default=>0
        Time :last_use, :null=>false, :default=>Sequel::CURRENT_TIMESTAMP
      end

      # Used by the recovery codes feature
      create_table(:account_recovery_codes) do
        foreign_key :id, :accounts, :type=>:Bignum
        String :code
        primary_key [:id, :code]
      end

      # Used by the sms codes feature
      create_table(:account_sms_codes) do
        foreign_key :id, :accounts, :primary_key=>true, :type=>:Bignum
        String :phone_number, :null=>false
        Integer :num_failures
        String :code
        DateTime :code_issued_at, :null=>false, :default=>Sequel::CURRENT_TIMESTAMP
      end

      case database_type
      when :postgres
        user = get(Sequel.lit('current_user')) + '_password'
        run "GRANT REFERENCES ON accounts TO #{user}"
      when :mysql, :mssql
        user = if database_type == :mysql
          get(Sequel.lit('current_user')).sub(/_password@/, '@')
        else
          get(Sequel.function(:DB_NAME))
        end
        run "GRANT ALL ON account_statuses TO #{user}"
        run "GRANT ALL ON accounts TO #{user}"
        run "GRANT ALL ON account_password_reset_keys TO #{user}"
        run "GRANT ALL ON account_jwt_refresh_keys TO #{user}"
        run "GRANT ALL ON account_verification_keys TO #{user}"
        run "GRANT ALL ON account_login_change_keys TO #{user}"
        run "GRANT ALL ON account_remember_keys TO #{user}"
        run "GRANT ALL ON account_login_failures TO #{user}"
        run "GRANT ALL ON account_lockouts TO #{user}"
        run "GRANT ALL ON account_email_auth_keys TO #{user}"
        run "GRANT ALL ON account_password_change_times TO #{user}"
        run "GRANT ALL ON account_activity_times TO #{user}"
        run "GRANT ALL ON account_session_keys TO #{user}"
        run "GRANT ALL ON account_otp_keys TO #{user}"
        run "GRANT ALL ON account_recovery_codes TO #{user}"
        run "GRANT ALL ON account_sms_codes TO #{user}"
      end
    end

    down do
      drop_table(:account_sms_codes,
                 :account_recovery_codes,
                 :account_otp_keys,
                 :account_session_keys,
                 :account_activity_times,
                 :account_password_change_times,
                 :account_email_auth_keys,
                 :account_lockouts,
                 :account_login_failures,
                 :account_remember_keys,
                 :account_login_change_keys,
                 :account_verification_keys,
                 :account_jwt_refresh_keys,
                 :account_password_reset_keys,
                 :accounts,
                 :account_statuses)
    end
  end

Second migration, run using the +ph+ account:

  require 'rodauth/migrations'

  Sequel.migration do
    up do
      create_table(:account_password_hashes) do
        foreign_key :id, :accounts, :primary_key=>true, :type=>:Bignum
        String :password_hash, :null=>false
      end
      Rodauth.create_database_authentication_functions(self)
      case database_type
      when :postgres
        user = get(Sequel.lit('current_user')).sub(/_password\z/, '')
        run "REVOKE ALL ON account_password_hashes FROM public"
        run "REVOKE ALL ON FUNCTION rodauth_get_salt(int8) FROM public"
        run "REVOKE ALL ON FUNCTION rodauth_valid_password_hash(int8, text) FROM public"
        run "GRANT INSERT, UPDATE, DELETE ON account_password_hashes TO #{user}"
        run "GRANT SELECT(id) ON account_password_hashes TO #{user}"
        run "GRANT EXECUTE ON FUNCTION rodauth_get_salt(int8) TO #{user}"
        run "GRANT EXECUTE ON FUNCTION rodauth_valid_password_hash(int8, text) TO #{user}"
      when :mysql
        user = get(Sequel.lit('current_user')).sub(/_password@/, '@')
        db_name = get(Sequel.function(:database))
        run "GRANT EXECUTE ON #{db_name}.* TO #{user}"
        run "GRANT INSERT, UPDATE, DELETE ON account_password_hashes TO #{user}"
        run "GRANT SELECT (id) ON account_password_hashes TO #{user}"
      when :mssql
        user = get(Sequel.function(:DB_NAME))
        run "GRANT EXECUTE ON rodauth_get_salt TO #{user}"
        run "GRANT EXECUTE ON rodauth_valid_password_hash TO #{user}"
        run "GRANT INSERT, UPDATE, DELETE ON account_password_hashes TO #{user}"
        run "GRANT SELECT ON account_password_hashes(id) TO #{user}"
      end

      # Used by the disallow_password_reuse feature
      create_table(:account_previous_password_hashes) do
        primary_key :id, :type=>:Bignum
        foreign_key :account_id, :accounts, :type=>:Bignum
        String :password_hash, :null=>false
      end
      Rodauth.create_database_previous_password_check_functions(self)

      case database_type
      when :postgres
        user = get(Sequel.lit('current_user')).sub(/_password\z/, '')
        run "REVOKE ALL ON account_previous_password_hashes FROM public"
        run "REVOKE ALL ON FUNCTION rodauth_get_previous_salt(int8) FROM public"
        run "REVOKE ALL ON FUNCTION rodauth_previous_password_hash_match(int8, text) FROM public"
        run "GRANT INSERT, UPDATE, DELETE ON account_previous_password_hashes TO #{user}"
        run "GRANT SELECT(id, account_id) ON account_previous_password_hashes TO #{user}"
        run "GRANT USAGE ON account_previous_password_hashes_id_seq TO #{user}"
        run "GRANT EXECUTE ON FUNCTION rodauth_get_previous_salt(int8) TO #{user}"
        run "GRANT EXECUTE ON FUNCTION rodauth_previous_password_hash_match(int8, text) TO #{user}"
      when :mysql
        user = get(Sequel.lit('current_user')).sub(/_password@/, '@')
        db_name = get(Sequel.function(:database))
        run "GRANT EXECUTE ON #{db_name}.* TO #{user}"
        run "GRANT INSERT, UPDATE, DELETE ON account_previous_password_hashes TO #{user}"
        run "GRANT SELECT (id, account_id) ON account_previous_password_hashes TO #{user}"
      when :mssql
        user = get(Sequel.function(:DB_NAME))
        run "GRANT EXECUTE ON rodauth_get_previous_salt TO #{user}"
        run "GRANT EXECUTE ON rodauth_previous_password_hash_match TO #{user}"
        run "GRANT INSERT, UPDATE, DELETE ON account_previous_password_hashes TO #{user}"
        run "GRANT SELECT ON account_previous_password_hashes(id, account_id) TO #{user}"
      end
    end

    down do
      Rodauth.drop_database_previous_password_check_functions(self)
      Rodauth.drop_database_authentication_functions(self)
      drop_table(:account_previous_password_hashes, :account_password_hashes)
    end
  end

To support multiple separate migration users, you can run the migration
for the password user using Sequel's migration API: 

  Sequel.extension :migration
  Sequel.postgres('DATABASE_NAME', :user=>'PASSWORD_USER_NAME') do |db|
    Sequel::Migrator.run(db, 'path/to/password_user/migrations', :table=>'schema_info_password')
  end

If the database is not PostgreSQL, MySQL, or Microsoft SQL Server, or you
cannot use multiple user accounts, just combine the two migrations into a
single migration.

One thing to notice in the above migrations is that Rodauth uses additional
tables for additional features, instead of additional columns in a single
table.

=== Locking Down (PostgreSQL only)

After running the migrations, you can increase security slightly by making
it not possible for the +ph+ account to login to the database directly.
This can be accomplished by modifying the +pg_hba.conf+ file.  You can also
consider restricting access using GRANT/REVOKE.

You can restrict access to the database itself to just the +app+ account.  You
can run this using the +app+ account, since that account owns the database:

  GRANT ALL ON DATABASE ${DATABASE_NAME} TO ${DATABASE_NAME};
  REVOKE ALL ON DATABASE ${DATABASE_NAME} FROM public;

You can also restrict access to the public schema (this is not needed if you
are using a custom schema).  Note that by default, the database superuser
owns the public schema, so you have to run this as the database superuser
account (generally +postgres+):

  GRANT ALL ON SCHEMA public TO ${DATABASE_NAME};
  GRANT USAGE ON SCHEMA public TO ${DATABASE_NAME}_password;
  REVOKE ALL ON SCHEMA public FROM public;

If you are using MySQL or Microsoft SQL Server, please consult their
documentation for how to restrict access so that the +ph+ account cannot
login directly.

== Usage

=== Basic Usage

Rodauth is a Roda plugin and loaded the same way other Roda plugins
are loaded:

  plugin :rodauth do
  end

The block passed to the plugin call uses the Rodauth configuration DSL.
The one configuration method that should always be used is +enable+,
which chooses which features you would like to load:

  plugin :rodauth do
    enable :login, :logout
  end

Once features are loaded, you can use any of the configuration methods
supported by the features.  There are two types of configuration
methods.  The first type are called auth methods, and they take a
block which overrides the default method that Rodauth uses.  Inside the
block, you can call super if you want to get the default behavior, though
you must provide explicit arguments to super.  There is no need to
call super in before or after hooks, though. For example, if you want to
add additional logging when a user logs in:

  plugin :rodauth do
    enable :login, :logout
    after_login do
      LOGGER.info "#{account[:email]} logged in!"
    end
  end

Inside the block, you are in the context of the Rodauth::Auth
instance related to the request.  This object has access to everything
related to the request via methods:

request :: RodaRequest instance
response :: RodaResponse instance
scope :: Roda instance
session :: session hash
flash :: flash message hash
account :: account hash (if set by an earlier Rodauth method)

So if you want to log the IP address for the user during login:

  plugin :rodauth do
    enable :login, :logout
    after_login do
      LOGGER.info "#{account[:email]} logged in from #{request.ip}"
    end
  end

The second type of configuration methods are called auth value
methods.  They are similar to auth methods, but instead of just
accepting a block, they can optionally accept a single argument
without a block, which will be treated as a block that just returns
that value.  For example, the accounts_table method sets the database
table storing accounts, so to override it, you can call the method
with a symbol for the table:

  plugin :rodauth do
    enable :login, :logout
    accounts_table :users
  end

Note that all auth value methods can still take a block, allowing
overriding for all behavior, using any information from the request:

  plugin :rodauth do
    enable :login, :logout
    accounts_table do
      request.ip.start_with?("192.168.1") ? :admins : :users
    end
  end

By allowing every configuration method to take a block, Rodauth
should be flexible enough to integrate into most legacy systems.

=== Plugin Options

When loading the rodauth plugin, you can also pass an options hash,
which configures which dependent plugins should be loaded. Options:

:csrf :: Set to +false+ to not load a csrf plugin.  Set to +:route_csrf+
         to use the route_csrf plugin instead of the csrf plugin. It is
         recommended to set the +:route_csrf+ option as that allows
         for more secure request-specific CSRF tokens.
:flash :: Set to +false+ to not load the flash plugin
:json :: Set to +true+ to load the json and json_parser plugins. Set
         to +:only+ to only load those plugins and not any other plugins.
         Note that if you are enabling features that send email, you
         still need to load the render plugin manually.
:name :: Provide a name for the given Rodauth configuration, used to
         support multiple Rodauth configurations in a given Roda application.

=== Feature Documentation

The options/methods for the supported features are listed on a
separate page per feature.  If these links are not active, please
view the appropriate file in the doc directory.

* {Base}[rdoc-ref:doc/base.rdoc] (this feature is autoloaded)
* {Login Password Requirements Base}[rdoc-ref:doc/login_password_requirements_base.rdoc] (this feature is autoloaded by features that set logins/passwords)
* {Email Base}[rdoc-ref:doc/email_base.rdoc] (this feature is autoloaded by features that send email)
* {Two Factor Base}[rdoc-ref:doc/two_factor_base.rdoc] (this feature is autoloaded by 2 factor authentication features)
* {Login}[rdoc-ref:doc/login.rdoc]
* {Logout}[rdoc-ref:doc/logout.rdoc]
* {Change Password}[rdoc-ref:doc/change_password.rdoc]
* {Change Password Notify}[rdoc-ref:doc/change_password_notify.rdoc]
* {Change Login}[rdoc-ref:doc/change_login.rdoc]
* {Reset Password}[rdoc-ref:doc/reset_password.rdoc]
* {Create Account}[rdoc-ref:doc/create_account.rdoc]
* {Close Account}[rdoc-ref:doc/close_account.rdoc]
* {Verify Account}[rdoc-ref:doc/verify_account.rdoc]
* {Confirm Password}[rdoc-ref:doc/confirm_password.rdoc]
* {Remember}[rdoc-ref:doc/remember.rdoc]
* {Lockout}[rdoc-ref:doc/lockout.rdoc]
* {Email Authentication}[rdoc-ref:doc/email_auth.rdoc]
* {OTP}[rdoc-ref:doc/otp.rdoc]
* {Recovery Codes}[rdoc-ref:doc/recovery_codes.rdoc]
* {SMS Codes}[rdoc-ref:doc/sms_codes.rdoc]
* {Verify Login Change}[rdoc-ref:doc/verify_login_change.rdoc]
* {Verify Change Login}[rdoc-ref:doc/verify_change_login.rdoc]
* {Verify Account Grace Period}[rdoc-ref:doc/verify_account_grace_period.rdoc]
* {Password Grace Period}[rdoc-ref:doc/password_grace_period.rdoc]
* {Password Complexity}[rdoc-ref:doc/password_complexity.rdoc]
* {Disallow Password Reuse}[rdoc-ref:doc/disallow_password_reuse.rdoc]
* {Disallow Common Passwords}[rdoc-ref:doc/disallow_common_passwords.rdoc]
* {Update Password Hash}[rdoc-ref:doc/update_password_hash.rdoc]
* {Password Expiration}[rdoc-ref:doc/password_expiration.rdoc]
* {Account Expiration}[rdoc-ref:doc/account_expiration.rdoc]
* {Session Expiration}[rdoc-ref:doc/session_expiration.rdoc]
* {Single Session}[rdoc-ref:doc/single_session.rdoc]
* {JWT}[rdoc-ref:doc/jwt.rdoc]
* {JWT}[rdoc-ref:doc/jwt_refresh.rdoc]
* {HTTP Basic Auth}[rdoc-ref:doc/http_basic_auth.rdoc]

=== Calling Rodauth in the Routing Tree

In general, you will usually want to call rodauth early in your
route block:

  route do |r|
    r.rodauth

    # ...
  end

Note that will allow Rodauth to run, but it won't force people
to login or add any security to your site.  If you want to force
all users to login, you need to redirect to them login page if
they are not already logged in:

  route do |r|
    r.rodauth
    rodauth.require_authentication

    # ...
  end

If only certain parts of your site require logins, then you can
only redirect if they are not logged in certain branches of the
routing tree:

  route do |r|
    r.rodauth

    r.on "admin" do
      rodauth.require_authentication

      # ...
    end

    # ...
  end

In some cases you may want to have rodauth run inside a branch of
the routing tree, instead of in the root.  You can do this by
setting a +:prefix+ when configuring Rodauth, and calling +r.rodauth+
inside a matching routing tree branch:

  plugin :rodauth do
    enable :login, :logout
    prefix "/auth"
  end

  route do |r|
    r.on "auth" do
      r.rodauth
    end

    rodauth.require_authentication

    # ...
  end

=== +rodauth+ Methods

Most of Rodauth's functionality is exposed via +r.rodauth+, which allows
Rodauth to handle routes for the features you have enabled (such as +/login+
for login).  However, as you have seen above, you may want to call methods on
the +rodauth+ object, such as for checking if the current request has been
authenticated.

Here are methods designed to be callable on the +rodauth+ object outside
+r.rodauth+:

require_login :: Require the session be logged in, redirecting the request to the
                 login page if the request has not been logged in.
require_authentication :: Similar to +require_login+, but also requires
                          two factor authentication if the account has setup
                          two factor authentication.  Redirects the request to
                          the two factor authentication page if logged in but not
                          authenticated via two factors.
logged_in? :: Whether the session has been logged in.
authenticated? :: Similar to +logged_in?+, but if the account has setup two
                  factor authentication, whether the session has authenticated
                  via two factors.
require_two_factor_setup :: (two_factor_base feature) Require the session to have
                            setup two factor authentication, redirecting the
                            request to the two factor authentication setup page
                            if not.
uses_two_factor_authentication? :: (two_factor_base feature) Whether the account
                                   for the current session has setup two factor
                                   authentication.
update_last_activity :: (account_expiration feature) Update the last activity
                        time for the current account.  Only makes sense to use
                        this if you are expiring accounts based on last activity.
require_current_password :: (password_expiration feature) Require a current
                            password, redirecting the request to the change
                            password page if the password for the account has
                            expired.
load_memory :: (remember feature) If the session has not been authenticated, look
               for the remember cookie.  If present and valid, automatically
               log the session in, but mark that it was logged in via a remember
               key.
logged_in_via_remember_key? :: (remember feature) Whether the current session has
                               been logged in via a remember key.  For security
                               sensitive actions where you want to require the user
                               to reenter the password, you can use the
                               confirm_password feature.
check_session_expiration :: (session_expiration feature) Check whether the current
                            session has expired, automatically logging the session
                            out if so.
check_single_session :: (single_session feature) Check whether the current
                        session is still the only valid session, automatically logging
                        the session out if not.
verified_account? :: (verify_grace_period feature) Whether the account is currently
                     verified.  If false, it is because the account is allowed to
                     login as they are in the grace period.
locked_out? :: (lockout feature) Whether the account for the current session has been
               locked out.

=== With Multiple Configurations

Rodauth supports using multiple rodauth configurations in the same
application.  You just need to load the plugin a second time,
providing a name for any alternate configuration:

  plugin :rodauth do
  end
  plugin :rodauth, :name=>:secondary do
  end

Then in your routing code, any time you call rodauth, you can provide
the name as an argument to use that configuration:

  route do |r|
    r.on 'secondary' do
      r.rodauth(:secondary)
    end

    r.rodauth
  end

=== With Password Hashes Inside the Accounts Table

You can use Rodauth if you are storing password hashes in the same
table as the accounts.  You just need to specify which column
stores the password hash:

  plugin :rodauth do
    account_password_hash_column :password_hash
  end

When this option is set, Rodauth will do the password hash check
in ruby.
  
=== When Using PostgreSQL/MySQL/Microsoft SQL Server without Database Functions

If you want to use Rodauth on PostgreSQL, MySQL, or Microsoft SQL Server
without using database functions for authentication, but still storing password
hashes in a separate table, you can do so:

  plugin :rodauth do
    use_database_authentication_functions? false
  end

Conversely, if you implement the rodauth_get_salt and
rodauth_valid_password_hash functions on a database that isn't
PostgreSQL, MySQL, or Microsoft SQL Server, you can set this value to true.

=== With Custom Authentication

You can use Rodauth with other authentication types, by using some
of Rodauth's configuration methods.

Note that when using custom authentication, using some of Rodauth's
features such as change login and change password either would not
make sense or would require some additional custom configuration.
The login and logout features should work correctly with the examples
below, though.

==== Using LDAP Authentication

If you have accounts stored in the database, but authentication happens
via LDAP, you can use the +simple_ldap_authenticator+ library:

  require 'simple_ldap_authenticator'
  plugin :rodauth do
    enable :login, :logout
    require_bcrypt? false
    password_match? do |password|
      SimpleLdapAuthenticator.valid?(account[:email], password)
    end
  end

If you aren't storing accounts in the database, but want to allow
any valid LDAP user to login, you can do something like this:

  require 'simple_ldap_authenticator'
  plugin :rodauth do
    enable :login, :logout

    # Don't require the bcrypt library, since using LDAP for auth
    require_bcrypt? false

    # Store session value in :login key, since the :account_id
    # default wouldn't make sense
    session_key :login

    # Use the login provided as the session value
    account_session_value{account}

    # Treat the login itself as the account
    account_from_login{|l| l.to_s}

    password_match? do |password|
      SimpleLdapAuthenticator.valid?(account, password)
    end
  end

==== Using Facebook Authentication

Here's an example of authentication using Facebook with a JSON API.
This setup assumes you have client-side code to submit JSON POST requests
to +/login+ with an +access_token+ parameter that is set to the user's
Facebook OAuth access token.


  require 'koala'
  plugin :rodauth do
    enable :login, :logout, :jwt
     
    require_bcrypt? false
    session_key :facebook_email
    account_session_value{account}

    login_param 'access_token'

    account_from_login do |access_token|
      fb = Koala::Facebook::API.new(access_token)
      if me = fb.get_object('me', :fields=>[:email])
        me['email']
      end
    end

    # there is no password!
    password_match? do |pass|
      true
    end
  end

=== With Other Web Frameworks

You can use Rodauth even if your application does not use the Roda web
framework.  This is possible by adding a Roda middleware that uses
Rodauth:

  require 'roda'

  class RodauthApp < Roda
    plugin :middleware
    plugin :rodauth do
      enable :login
    end

    route do |r|
      r.rodauth
      rodauth.require_authentication
      env['rodauth'] = rodauth
    end
  end

  use RodauthApp

Note that Rodauth expects the Roda app it is used in to provide a
layout.  So if you are using Rodauth as middleware for another app,
if you don't have a +views/layout.erb+ file that Rodauth can use,
you should probably also add load Roda's +render+ plugin
with the appropriate settings that allow Rodauth to use the same
layout as the application.

By setting <tt>env['rodauth'] = rodauth</tt> in the route block
inside the middleware, you can easily provide a way for your
application to call Rodauth methods.

Here are some examples of integrating Rodauth into applications that
don't use Roda:

* {Ginatra, a Sinatra-based git repository viewer}[https://github.com/jeremyevans/ginatra/commit/28108ebec96e8d42596ee55b01c3f7b50c155dd1] 
* {Rodauth's demo site as a Rails application}[https://github.com/jeremyevans/rodauth-demo-rails] (
  This uses the {roda-rails gem}[https://github.com/jeremyevans/roda-rails]
  so that Rodauth uses Rails' CSRF and flash support)
* {Grape application}[https://github.com/davydovanton/grape-rodauth]
* {Hanami application}[https://github.com/davydovanton/rodauth_hanami]

=== Using 2 Factor Authentication

Rodauth ships with 2 factor authentication support via TOTP (Time-Based
One-Time Passwords, RFC 6238).  There are a wide variety of ways in
which to integrate 2 factor authentication into your site with Rodauth,
based on the needs of the application.

The 2 factor authentication support is part of the OTP feature, which
needs to be enabled in addition to the login feature.  In addition,
when implementing 2 factor authentication, you should generally
provide a backup 2nd factor if the primary second factor is not
available.  Rodauth supports SMS codes and recovery codes as other
2nd factors.

If you want to support but not require 2 factor authentication:

  plugin :rodauth do
    enable :login, :logout, :otp, :recovery_codes, :sms_codes
  end
  route do |r|
    r.rodauth
    rodauth.require_authentication

    # ...
  end

If you want to force all users to use OTP authentication, requiring users
that don't currently have two authentication to set it up:

  route do |r|
    r.rodauth
    rodauth.require_authentication
    rodauth.require_two_factor_setup

    # ...
  end

Similarly to requiring authentication in general, it's possible to require
login authentication for most of the site, but require 2 factor
authentication only for particular branches:

  route do |r|
    r.rodauth
    rodauth.require_login

    r.on "admin" do
      rodauth.require_two_factor_authenticated
    end

    # ...
  end

=== JSON API Support

To add support for handling JSON responses, you can pass the +:json+
option to the plugin, and enable the JWT feature in addition to
other features you plan to use:

  plugin :rodauth, :json=>true do
    enable :login, :logout, :jwt
  end

If you do not want to load the HTML plugins that Rodauth usually loads
(render, csrf, flash, h), because you are building a JSON-only API,
pass <tt>:json => :only</tt>

  plugin :rodauth, :json=>:only do
    enable :login, :logout, :jwt
  end

Note that by default, the features that send email depend on the
render plugin, so if using the <tt>:json=>:only</tt> option, you
either need to load the render plugin manually or you need to
use the necessary *_email_body configuration options to specify
the body of the emails.

The JWT feature enables JSON API support for all of the other features
that Rodauth ships with.

=== Adding Custom Methods to the +rodauth+ Object

Inside the configuration block, you can use +auth_class_eval+ to add
custom methods that will be callable on the +rodauth+ object.

  plugin :rodauth do
    enable :login

    auth_class_eval do
      def require_admin
        request.redirect("/") unless account[:admin]
      end
    end
  end

  route do |r|
    r.rodauth

    r.on "admin" do
      rodauth.require_admin
    end
  end

=== Using External Features

The enable configuration method is able to load features external to
Rodauth.  You need to place the external feature file where it can be
required via rodauth/features/feature_name. That file should
use the following basic structure

  module Rodauth
    # :feature_name will be the argument given to enable to
    # load the feature, :FeatureName is optional and will be used to
    # set a constant name for prettier inspect output.
    Feature.define(:feature_name, :FeatureName) do
      # Shortcut for defining auth value methods with static values
      auth_value_method :method_name, 1 # method_value

      auth_value_methods # one argument per auth value method

      auth_methods # one argument per auth method
 
      route do |r|
        # This block is taken for requests to the feature's route.
        # This block is evaluated in the scope of the Rodauth::Auth instance.
        # r is the Roda::RodaRequest instance for the request
        
        r.get do
        end

        r.post do
        end
      end

      configuration_eval do
        # define additional configuration specific methods here, if any
      end

      # define the default behavior for the auth_methods
      # and auth_value_methods
      # ...
    end
  end

See the source code for the features that ship with Rodauth for an
example of how to construct features.

=== Overriding Route-Level Behavior

All of Rodauth's configuration methods change the behavior of the
Rodauth::Auth instance.  However, in some cases you may want to
overriding handling at the routing layer.  You can do this easily
by adding an appropriate route before calling +r.rodauth+:

  route do |r|
    r.post 'login' do
      # Custom POST /login handling here
    end

    r.rodauth
  end

=== Precompiling Rodauth Templates

Rodauth serves templates from it's gem folder.  If you are using
a forking webserver and want to preload the compiled templates
to save memory, or if you are chrooting your application, you can
benefit from precompiling your rodauth templates:

  plugin :rodauth do
    # ...
  end
  precompile_rodauth_templates

== Similar Projects

All of these are Rails-specific:

* Devise
* Authlogic
* Sorcery

== Author

Jeremy Evans <code@jeremyevans.net>