webperl/Webperl/AuthMethod.pm

460 lines
20 KiB
Perl

## @file
# This file contains the implementation of the authentication method base class.
#
# @author Chris Page <chris@starforge.co.uk>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see http://www.gnu.org/licenses/.
## @class
# The base class for all authentication method classes. This class is
# mainly present for documentation purposes - it doesn't actually provide
# any meaningful implementation of an authentication method, and the
# actually interesting stuff should happen in subclasses of it.
package Webperl::AuthMethod;
use strict;
use base qw(Webperl::SystemModule);
# ============================================================================
# Constructor
## @cmethod $ new(%args)
# Construct a new AuthMethod object. This will create a new AuthMethod object
# initialised with the provided arguments.
#
# @param args A hash of arguments to initialise the AuthMethod object with.
# @return A new AuthMethod object.
sub new {
my $invocant = shift;
my $class = ref($invocant) || $invocant;
my $self = $class -> SUPER::new(@_)
or return undef;
$self -> {"capabilities"} = {"activate" => 0,
"activate_message" => $self -> {"noactivate_message"} || $self -> {"settings"} -> {"config"} -> {"AuthMethod::noactivate_message"},
"recover" => 0,
"recover_message" => $self -> {"norecover_message"} || $self -> {"settings"} -> {"config"} -> {"AuthMethod::norecover_message"},
"passchange" => 0,
"passchange_message" => $self -> {"nopasschange_message"} || $self -> {"settings"} -> {"config"} -> {"AuthMethod::nopasschange_message"},
"failcount" => 0,
"failcount_message" => $self -> {"nofailcount_message"} || $self -> {"settings"} -> {"config"} -> {"AuthMethod::nofailcount_message"},
};
# Set the default order of policy rules reported to the user
$self -> {"set_policy_order"} = ['policy_min_length',
'policy_min_lowercase',
'policy_min_uppercase',
'policy_min_digits',
'policy_min_other',
'policy_min_entropy',
'policy_use_cracklib',
'policy_max_passwordage',
'policy_max_loginfail' ];
# Map cracklib responses to localisable strings
$self -> {"cracklib_stirngs"} = { "it is WAY too short" => "LOGIN_CRACKLIB_WAYSHORT",
"it is too short" => "LOGIN_CRACKLIB_TOOSHORT",
"it does not contain enough DIFFERENT characters" => "LOGIN_CRACKLIB_MORECHARS",
"it is all whitespace" => "LOGIN_CRACKLIB_WHITESPACE",
"it is too simplistic/systematic" => "LOGIN_CRACKLIB_SIMPLISTIC",
"it looks like a National Insurance number" => "LOGIN_CRACKLIB_NINUMBER",
"it is based on a dictionary word" => "LOGIN_CRACKLIB_DICTWORD",
"it is based on a (reversed) dictionary word" => "LOGIN_CRACKLIB_DICTBACK",
};
return $self;
}
# ============================================================================
# Interface code
## @method $ create_user($username, $authmethod)
# Create a user account in the database. Note that, unless overridden in a subclass,
# this creates a 'stub' user in the database, with minimal information required to
# simply get a user ID needed for other areas of the system. If more complete data
# should be stored with the user, subclasses need to deal with that. For AuthMethods
# that do their authentication against other systems, this user creation function
# is sufficient to pass post_auth requirements - however, they may need to perform
# additional checks in their AppUser implementation to ensure that required fields
# (like email) are populated by the user before they continue.
#
# @param username The name of the user to create.
# @param authmethod The ID of the authmethod to set as the user's default authmethod.
# @return A reference to the new user's database entry on success, undef on error.
sub create_user {
my $self = shift;
my $username = shift;
my $authmethod = shift;
$self -> clear_error();
my $active = $self -> capabilities("activate") ? 0 : time();
my $newuser = $self -> {"dbh"} -> prepare("INSERT INTO ".$self -> {"settings"} -> {"database"} -> {"users"}."
(user_auth, activated, username, created, last_login)
VALUES(?, ?, ?, UNIX_TIMESTAMP(), UNIX_TIMESTAMP())");
$newuser -> execute($authmethod, $active, $username)
or $self -> self_error("Unable to create new user record: ".$self -> {"dbh"} -> errstr);
# FIXME: This ties to MySQL, but is more reliable that last_insert_id in general.
# Try to find a decent solution for this mess...
my $userid = $self -> {"dbh"} -> {"mysql_insertid"};
return $self -> self_error("Unable to obtain id for user '$username'") if(!$userid);
my $userh = $self -> {"dbh"} -> prepare("SELECT * FROM ".$self -> {"settings"} -> {"database"} -> {"users"}."
WHERE user_id = ?");
$userh -> execute($userid)
or return $self -> self_error("Unable to fetch user record: ".$self -> {"dbh"} -> errstr);
return $userh -> fetchrow_hashref();
}
## @method @ authenticate($username, $password, $auth)
# Authenticate a user based on the credentials supplied. This will attempt
# to determine whether the user's credentials are valid, and will return
# true if they are, or false if they are not or a problem occured while
# performing the authentication.
#
# @param username The username of the user to authenticate.
# @param password The password of the user to authenticate.
# @param auth A reference to the Auth object calling this function,
# if any errors are encountered while performing the
# authentication, they will be set in $auth -> {"errstr"}.
# @return true if the user's credentials are valid, false otherwise. Some
# AuthMethods may also return an additional value: a reference to a
# hash containing values to set for the user. Keys may be system-specific,
# and may require a custom AppUser implementation to use properly, but
# recommended keys are "email" and "realname", but other fields may be included.
sub authenticate {
my $self = shift;
my $username = shift;
my $password = shift;
my $auth = shift;
# This class does not know how to authenticate users, always return false.
return 0;
}
## @method $ capabilities($capability)
# Interrogate the capabilities of the authentication method. This will either
# return a reference to a hash containing the capability information for the
# auth method or, if a valid capability argument is specified, this returns
# the value for that capability.
#
# @param capability The optional name of the capability to obtain the value for.
# @return If no 'capabilities' argument is provided, a reference to a hash
# containing all of the authmethod's capabilities. If a capability is
# specified, this returns the value for it, or undef if the requested
# capability is unknown.
sub capabilities {
my $self = shift;
my $capability = shift;
return($self -> {"capabilities"} -> {$capability})
if($capability && $self -> {"capabilities"});
return $self -> {"capabilities"};
}
## @method $ generate_actcode($userid)
# Generate a new activation code for the specified user.
#
# @param userid The ID of the user to reset the actcode for
# @return The new activation code for the user
sub generate_actcode {
my $self = shift;
my $userid = shift;
# do nothing as activation is not required
return $self -> self_error($self -> capabilities("activate_message"));
}
## @method $ activated($userid)
# Determine whether the user account specified has been activated.
#
# @param userid The ID of the user account to check the activation status of.
# @return true if the user has been activated (actually, the unix timestamp of
# their activation), 0 if the user has not been activated/does not exist,
# or undef on error.
sub activated {
my $self = shift;
# By default, users are always active, as activation is not required.
return 1;
}
## @method $ activate_user($userid)
# Activate the user account with the specified id. This clears the user's
# activation code, and sets the activation timestamp.
#
# @param userid The ID of the user account to activate.
# @return True on success, undef on error.
sub activate_user {
my $self = shift;
my $userid = shift;
# Activation will always fail if not needed
return $self -> self_error($self -> capabilities("activate_message"));
}
## @method @ reset_password_actcode($userid)
# Forcibly reset the user's password and activation code to new random values.
#
# @param userid The ID of the user to reset the password and act code for
# @return The new password and activation code set for the user, undef on error.
sub reset_password_actcode {
my $self = shift;
my $userid = shift;
# Do nothing, as by default activation and password change are not supported
return $self -> self_error($self -> capabilities("recover_message"));
}
## @method $ reset_password($userid)
# Forcibly reset the user's password to a new random value.
#
# @param userid The ID of the user to reset the password for
# @return The (unencrypted) new password set for the user, undef on error.
sub reset_password {
my $self = shift;
my $userid = shift;
# Do nothing as password changes are not supported
return $self -> self_error($self -> capabilities("passchange_message"));
}
## @method $ set_password($userid, $password)
# Set the user's password to the specified value.
#
# @param userid The ID of the user to set the password for
# @param password The password to set for the user.
# @return True on success, undef on error.
sub set_password {
my $self = shift;
my $userid = shift;
# Do nothing as password changes are not supported
return $self -> self_error($self -> capabilities("passchange_message"));
}
## @method $ force_passchange($userid)
# Determine whether the user needs to reset their password (either because they are
# using a temporary system-allocated password, or the password policy requires it).
#
# If a password expiration policy is in use, `policy_max_passwordage` should be set
# in the auth_method_params for the applicable authmethods. The parameter should contain
# the maximum age of any given password in days. If not set, expiration is not
# enforced.
#
# @param userid The ID of the user to check for password change requirement.
# @return A string indicating why the user must change their password if they need
# to, the empty string if they do not, undef on error.
sub force_passchange {
my $self = shift;
my $userid = shift;
# By default, AuthMethods do not support password changing, so they can't force it.
return ''
}
## @method $ mark_login($userid)
# Update a user's internal record to reflect the fact that they have successfully
# logged in.
#
# @param userid The ID of the user who has successfully logged in.
# @return true on success, undef on error.
sub mark_login {
my $self = shift;
my $userid = shift;
my $pokeh = $self -> {"dbh"} -> prepare("UPDATE ".$self -> {"settings"} -> {"database"} -> {"users"}."
SET last_login = UNIX_TIMESTAMP()
WHERE user_id = ?");
$pokeh -> execute($userid)
or return $self -> self_error("Unable to update user record: ".$self -> {"dbh"} -> errstr);
return 1;
}
## @method @ mark_loginfail($userid)
# Increment the login failure count for the specified user. The following configuration
# parameter (which should be set for each applicable authmethod in the auth_method_params
# table) is used to control the login failure marking process:
#
# - `policy_max_loginfail`, the number of login failures a user may have before their
# account is deactivated.
#
# @warning Login failure limiting should not be performed unless account activation
# and password changes are supported. Otherwise the system has no means of
# preventing attempts to log in past the limit.
#
# @param userid The ID of the user to increment the login failure counter for.
# @return An array containing two values: The first is the number of login failures
# recorded for the user, the second is the number of allowed failures. If
# the second value is zero, no failure limiting is being performed. If an error
# occurs or the user does not exist, both values are undef.
sub mark_loginfail {
my $self = shift;
my $userid = shift;
# login failure counting is not supported by default, so users never get deactivated.
return (0, 0);
}
## @method $ apply_policy($password)
# Apply the configured password policy to the specified password string.
# The following configuration parameters (which should be set for each applicable
# authmethod in the auth_method_params table) are used to control the policy. If
# no value is set for a given parameter, the policy is assumed to not care about
# the parameter:
#
# - `policy_min_length`, passwords must be at least this number of characters long.
# - `policy_min_lowercase`, at least this number of lowercase characters must be present.
# - `policy_min_uppercase`, at least this many uppercase characters must be included.
# - `policy_min_digits`, the minimum number of digits that must be used.
# - `policy_min_other`, the number of non-alphanumeric characters that must be present.
# - `policy_min_entropy`, the minimum password entropy (as calculated by Data::Password::Entropy)
# to allow for passwords. See
# - `policy_use_cracklib`, if true, passwords are checked using cracklib.
#
# @param password The password string to check against the password policy.
# @return undef if the password passes the password policy, otherwise a reference to
# a hash, the keys forming the names of the policy rules failed, and the values
# being array references containing the settings for the policy rule and the value
# detected.
sub apply_policy {
my $self = shift;
my $password = shift;
my $failures = {};
$failures -> {"policy_min_length"} = [ $self -> {"policy_min_length"}, length($password) ]
if($self -> {"policy_min_length"} && length($password) < $self -> {"policy_min_length"});
my $lowercount = $password =~ tr/a-z//;
$failures -> {"policy_min_lowercase"} = [ $self -> {"policy_min_lowercase"}, $lowercount ]
if($self -> {"policy_min_lowercase"} && $lowercount < $self -> {"policy_min_lowercase"});
my $uppercount = $password =~ tr/A-Z//;
$failures -> {"policy_min_uppercase"} = [ $self -> {"policy_min_uppercase"}, $uppercount ]
if($self -> {"policy_min_uppercase"} && $uppercount < $self -> {"policy_min_uppercase"});
my $digitcount = $password =~ tr/0-9//;
$failures -> {"policy_min_digits"} = [ $self -> {"policy_min_digits"}, $digitcount ]
if($self -> {"policy_min_digits"} && $digitcount < $self -> {"policy_min_digits"});
my $othercount = length($password) - ($lowercount + $uppercount + $digitcount);
$othercount = 0 if($othercount < 0); # Impossibru! But check it anyway.
$failures -> {"policy_min_others"} = [ $self -> {"policy_min_others"}, $othercount ]
if($self -> {"policy_min_others"} && $othercount < $self -> {"policy_min_others"});
# Check against Data::Password::Entropy if possible
if($self -> {"policy_min_entropy"}) {
# Load the entropy module at runtime, so that systems that don't test entropy don't need it...
eval {
require Data::Password::Entropy;
Data::Password::Entropy -> import();
};
# Handle attempted load that fails. This is transparent to users, which may be a bad thing....
if($@) {
$self -> {"logger"} -> log("error", 0, undef, "policy_min_entropy is set, but unable to load Data::Password::Entropy!");
} else {
my $entropy = password_entropy($password);
$failures -> {"policy_min_entropy"} = [ $self -> {"policy_min_entropy"}, $entropy ]
if($entropy < $self -> {"policy_min_entropy"});
}
}
# Potentially invoke cracklib
if($self -> {"policy_use_cracklib"}) {
# Load the cracklib module at runtime, so that systems that don't test against it don't need it...
eval {
require Crypt::Cracklib;
Crypt::Cracklib -> import();
};
# Handle attempted load that fails. This is transparent to users, which may be a bad thing....
if($@) {
$self -> {"logger"} -> log("error", 0, undef, "policy_use_cracklib is set, but unable to load Crypt::Cracklib!");
} else {
my $crackres = fascist_check($password);
if(lc($crackres) ne "ok") {
# Cracklib is unlocalised and returns pretty lousy fedback strings, try to map them to something useful
my $mapres = $self -> {"cracklib_stirngs"} -> {$crackres} || $crackres;
# If mapres is the same as crackres (ie: mapping to a localisable string ID failed),
# try to at least make it more readable
if($mapres eq $crackres) {
$mapres =~ s/^it/The password/;
# Otherwise, wrap in langvar marker stuff
} else {
$mapres = "{L_".$mapres."}";
}
$failures -> {"policy_use_cracklib"} = [1, $mapres]
}
}
}
if(scalar(%{$failures})) {
$failures -> {"policy_order"} = $self -> {"set_policy_order"};
return $failures;
}
return undef;
}
## @method $ get_policy()
# Obtain a hash containing the password policy settings. This generates a hash containing
# the details of the password policy (effectively, all 'policy_*' values set for the
# current AuthMethod) and returns a reference to it.
#
# @return A reference to a hash containing the AuthMethod's policy settings, if no
# policy is currently in place, this returns undef.
sub get_policy {
my $self = shift;
my %policy;
# Get the list of keys that start 'policy_'
my @policy_keys = grep {/^policy_/} keys %{$self};
# And a hash slice from those keys.
@policy{@policy_keys} = @$self{@policy_keys};
if(scalar(%policy)) {
$policy{"policy_order"} = $self -> {"set_policy_order"};
return \%policy;
}
return undef;
}
1;