#! /usr/bin/perl -T
# vim: set filetype=perl ts=4 sw=4 sts=4 et:
# NEEDGROUP osh-accountGrantCommand
# NEEDGROUP osh-accountRevokeCommand
# SUDOERS # grant access to a command
# SUDOERS %osh-accountGrantCommand  ALL=(root) NOPASSWD:/usr/bin/env perl -T /opt/bastion/bin/helper/osh-accountModifyCommand --action grant *
# SUDOERS # revoke access to a command
# SUDOERS %osh-accountRevokeCommand ALL=(root) NOPASSWD:/usr/bin/env perl -T /opt/bastion/bin/helper/osh-accountModifyCommand --action revoke *
# FILEMODE 0755
# FILEOWN 0 0

#>HEADER
use common::sense;
use Getopt::Long;

use File::Basename;
use lib dirname(__FILE__) . '/../../lib/perl';
use OVH::Bastion;
local $| = 1;

#
# Globals
#
$ENV{'PATH'} = '/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:/usr/pkg/bin';
my ($self) = $ENV{'SUDO_USER'} =~ m{^([a-zA-Z0-9._-]+)$};
if (not defined $self) {
    if ($< == 0) {
        $self = 'root';
    }
    else {
        HEXIT('ERR_SUDO_NEEDED', msg => 'This command must be run under sudo');
    }
}

# Fetch command options
Getopt::Long::Configure("no_auto_abbrev");
my $fnret;
my ($result, @optwarns);
my ($action, $account, $command);
eval {
    local $SIG{__WARN__} = sub { push @optwarns, shift };
    $result = GetOptions(
        "action=s"  => sub { $action  //= $_[1] },
        "account=s" => sub { $account //= $_[1] },
        "command=s" => sub { $command //= $_[1] },
    );
};
if ($@) { die $@ }

if (!$result) {
    local $" = ", ";
    HEXIT('ERR_BAD_OPTIONS', msg => "Error parsing options: @optwarns");
}

if (not $account or not $command or not $action) {
    HEXIT('ERR_MISSING_PARAMETER', msg => "Missing argument 'account', 'command' or 'action'");
}

#<HEADER

#>PARAMS:ACCOUNT
$fnret = OVH::Bastion::is_bastion_account_valid_and_existing(account => $account, localOnly => 1);
$fnret or HEXIT($fnret);

# get returned untainted value
$account = $fnret->value->{'account'};

#<PARAMS:ACCOUNT

#>PARAMS:ACTION
if ($action ne 'grant' && $action ne 'revoke') {
    HEXIT('ERR_INVALID_PARAMETER', msg => "Parameter 'action' must be 'grant' or 'revoke'");
}

#<PARAMS:ACTION

#>PARAMS:COMMAND
if ($command =~ m{^([a-z0-9]+)$}i) {
    $command = $1;    # untaint
}
else {
    HEXIT('ERR_INVALID_PARAMETER', msg => "Specified command is invalid ($command)");
}

#<PARAMS:COMMAND

#>RIGHTSCHECK
if ($self eq 'root') {
    osh_debug "Real root, skipping checks of permissions";
}
elsif ($action eq 'grant') {
    $fnret = OVH::Bastion::is_user_in_group(user => $self, group => "osh-accountGrantCommand");
    if (!$fnret) {
        HEXIT('ERR_SECURITY_VIOLATION', msg => "You're not allowed to run this, dear $self");
    }
}
elsif ($action eq 'revoke') {
    $fnret = OVH::Bastion::is_user_in_group(user => $self, group => "osh-accountRevokeCommand");
    if (!$fnret) {
        HEXIT('ERR_SECURITY_VIOLATION', msg => "You're not allowed to run this, dear $self");
    }
}

#<RIGHTSCHECK

#>CODE
$fnret = OVH::Bastion::get_plugin_list(restrictedOnly => 1);
$fnret or HEXIT($fnret);
my @plugins = sort keys %{$fnret->value};
push @plugins, 'auditor';

if (!grep { $command eq $_ } @plugins) {
    HEXIT('ERR_INVALID_PARAMETER', msg => "Specified command ($command) is not in the restricted plugins list");
}
if (grep { $command eq $_ } qw{ admin superowner }) {
    HEXIT('ERR_SECURITY_VIOLATION', msg => "Specified command ($command) can't be granted this way for security reasons");
}
if (grep { $command eq $_ } qw{ accountGrantCommand accountRevokeCommand } && !OVH::Bastion::is_admin(sudo => 1)) {
    HEXIT('ERR_SECURITY_VIOLATION', msg => "Specified command ($command) can only be granted by bastion admins for security reasons");
}

my $msg;
$fnret = OVH::Bastion::is_user_in_group(user => $account, group => "osh-$command");
if ($action eq 'grant') {
    HEXIT('OK_NO_CHANGE', msg => "Account $account already has the right to use the $command plugin, no change required") if $fnret;

    $fnret = OVH::Bastion::sys_addmembertogroup(user => $account, group => "osh-$command", noisy_stderr => 1);
    $fnret or HEXIT($fnret);

    $msg = "Successfully granted use of restricted command $command to $account";
}
elsif ($action eq 'revoke') {
    HEXIT('OK_NO_CHANGE', msg => "Account $account did not have the right to use the $command plugin, no change required") if !$fnret;

    $fnret = OVH::Bastion::sys_delmemberfromgroup(user => $account, group => "osh-$command", noisy_stderr => 1);
    $fnret or HEXIT($fnret);

    $msg = "Successfully revoked use of restricted command $command from $account";
}

HEXIT('OK', msg => $msg);