fix: workaround for undocumented caching in getpw/getgr funcs

This commit is contained in:
Stéphane Lesimple 2022-02-17 13:31:29 +00:00 committed by Stéphane Lesimple
parent d88cf637ee
commit effab4a5c2
7 changed files with 236 additions and 130 deletions

View file

@ -36,7 +36,7 @@ EOF
my $fnret;
$fnret = OVH::Bastion::get_group_list(groupType => "key");
$fnret = OVH::Bastion::get_group_list();
$fnret or osh_exit $fnret;
my $includere = OVH::Bastion::build_re_from_wildcards(wildcards => \@includes, implicit_contains => 1)->value;

View file

@ -118,9 +118,9 @@ osh_info sprintf("\nI am %s, aka %s", colored(Sys::Hostname::hostname(), 'green'
$ret{'hostname'} = Sys::Hostname::hostname();
$ret{'bastion_name'} = $config->{'bastionName'};
$fnret = OVH::Bastion::get_account_list();
$fnret = OVH::Bastion::get_account_list(cache => 1);
my $nbaccounts = $fnret ? keys %{$fnret->value} : '?';
$fnret = OVH::Bastion::get_group_list(groupType => 'key');
$fnret = OVH::Bastion::get_group_list(cache => 1);
my $nbgroups = $fnret ? keys %{$fnret->value} : '?';
osh_info "I have " . colored($nbaccounts, 'green') . " registered accounts and " . colored($nbgroups, 'green') . " groups";
$ret{'registered_accounts'} = $nbaccounts;

View file

@ -68,18 +68,18 @@ $ret{'allowed_commands'} = \@granted;
my $result_hash = {};
if ($listGroups) {
$fnret = OVH::Bastion::get_group_list(groupType => "key");
$fnret = OVH::Bastion::get_group_list(cache => 1);
$fnret or osh_exit $fnret;
osh_info "\nThis account is part of the following groups:";
foreach my $name (sort keys %{$fnret->value}) {
my @flags;
push @flags, 'owner' if OVH::Bastion::is_group_owner(group => $name, account => $account);
push @flags, 'gatekeeper' if OVH::Bastion::is_group_gatekeeper(group => $name, account => $account);
push @flags, 'aclkeeper' if OVH::Bastion::is_group_aclkeeper(group => $name, account => $account);
push @flags, 'member' if OVH::Bastion::is_group_member(group => $name, account => $account);
push @flags, 'guest' if OVH::Bastion::is_group_guest(group => $name, account => $account);
push @flags, 'owner' if OVH::Bastion::is_group_owner(group => $name, account => $account, cache => 1);
push @flags, 'gatekeeper' if OVH::Bastion::is_group_gatekeeper(group => $name, account => $account, cache => 1);
push @flags, 'aclkeeper' if OVH::Bastion::is_group_aclkeeper(group => $name, account => $account, cache => 1);
push @flags, 'member' if OVH::Bastion::is_group_member(group => $name, account => $account, cache => 1);
push @flags, 'guest' if OVH::Bastion::is_group_guest(group => $name, account => $account, cache => 1);
if (@flags) {
my $line = sprintf "%18s", $name;
$line .= sprintf " %14s", colored(grep({ $_ eq 'owner' } @flags) ? 'Owner' : '-', 'red');

View file

@ -141,7 +141,7 @@ my %_autoload_files = (
qw{ enable_mocking is_mocking set_mock_data mock_get_account_entry mock_get_account_accesses mock_get_account_personal_accesses mock_get_account_legacy_accesses mock_get_group_accesses mock_get_account_guest_accesses }
],
os => [
qw{ sysinfo is_linux is_debian is_redhat is_bsd is_freebsd is_openbsd is_netbsd has_acls sys_useradd sys_groupadd sys_userdel sys_groupdel sys_addmembertogroup sys_delmemberfromgroup sys_changepassword sys_neutralizepassword sys_setpasswordpolicy sys_getpasswordinfo sys_getsudoersfolder sys_setfacl is_in_path }
qw{ sysinfo is_linux is_debian is_redhat is_bsd is_freebsd is_openbsd is_netbsd has_acls sys_useradd sys_groupadd sys_userdel sys_groupdel sys_addmembertogroup sys_delmemberfromgroup sys_changepassword sys_neutralizepassword sys_setpasswordpolicy sys_getpasswordinfo sys_getsudoersfolder sys_setfacl is_in_path sys_getent_pw sys_getent_gr }
],
password => [qw{ get_hashes_from_password get_hashes_list is_valid_hash }],
ssh => [

View file

@ -340,9 +340,8 @@ sub ip2host {
return R('OK', value => $host);
}
# Return an array containing the groups for which user is a member of
my %_cache_get_user_groups;
# returns a list of the bastion groups (more precisely, the system group names
# mapped to these groups) a user is member of.
sub get_user_groups {
my %params = @_;
my $user = $params{'user'} || $params{'account'};
@ -353,19 +352,16 @@ sub get_user_groups {
return R('ERR_MISSING_PARAMETER', msg => "Missing parameter 'account'");
}
if (not %_cache_get_user_groups) {
# build cache, it'll be faster than even one exec `id -nG` anyway
setgrent();
while (my ($name, $passwd, $gid, $members) = getgrent()) {
foreach my $member (split / /, $members) {
push @{$_cache_get_user_groups{$member}}, $name;
# try to use sys_getent_gr()'s cache if available and allowed by caller.
# we loop through all the system groups to find the ones having user
# as a meember
my @groups;
foreach my $gr (@{OVH::Bastion::sys_getent_gr(cache => $cache)->value}) {
if (grep { $user eq $_ } @{$gr->{'members'} || []}) {
push @groups, $gr->{'name'};
}
}
setgrent();
}
my @groups = @{$_cache_get_user_groups{$user} || []};
my @availableGroups;
foreach my $group (@groups) {
if ($group =~ /^key.+-(gatekeeper|aclkeeper|owner)$/) {

View file

@ -6,61 +6,64 @@ use common::sense;
use Time::Piece; # $t->strftime
# used to speedup extensive calls to is_user_in_group() and is_group_existing(),
# if our caller allows us:
my %_cache_getgrnam;
# Check if user belongs to a specific group
# Check if a system user belongs to a specific system group
sub is_user_in_group {
my %params = @_;
my $group = $params{'group'};
my $user = $params{'user'} || OVH::Bastion::get_user_from_env()->value;
my $cache = $params{'cache'}; # if true, allow cache use from potential previous calls
my $cache = $params{'cache'}; # if true, allow cache use of sys_getent_gr()
# mandatory keys
if (!$user || !$group) {
return R('ERR_MISSING_PARAMETER', msg => "Missing parameter 'user' or 'group'");
}
# if we're not allowed to use cache, call getgrnam() in all cases.
# if we're allowed to use it; only call getgrnam() if we have no cache for this group
if (!$cache || (!$_cache_getgrnam{$group} || ref $_cache_getgrnam{$group} ne 'ARRAY')) {
$_cache_getgrnam{$group} = [(getgrnam($group))];
}
my ($groupname, $passwd, $gid, $members) = @{$_cache_getgrnam{$group}};
my @membersList = split / /, $members;
if (grep { $user eq $_ } @membersList) {
# try to use sys_getent_gr()'s cache if available and allowed by caller.
# we loop through all the system groups to find the proper one, then
# check whether $user appears in the member list
foreach my $gr (@{OVH::Bastion::sys_getent_gr(cache => $cache)->value}) {
next if $gr->{'name'} ne $group;
if (grep { $user eq $_ } @{$gr->{'members'} || []}) {
return R('OK', value => {account => $user});
}
else {
return R('KO_NOT_IN_GROUP', msg => "Account $user doesn't belong to the group $group");
}
}
return R('KO_GROUP_NOT_FOUND', msg => "The group $group doesn't exist");
}
# does this group exist ?
# uses %_cache_getgrnam defined above
# does this system group exist ? if it happens to be mapped to a bastion group,
# also return the corresponding "shortGroup" (with the "key" prefix removed)
sub is_group_existing {
my %params = @_;
my $group = $params{'group'};
my $cache = $params{'cache'}; # if true, allow cache use from potential previous calls
my $user_friendly_error = $params{'user_friendly_error'};
if (!$group) {
return R('ERR_MISSING_PARAMETER', msg => "Missing parameter 'group'");
}
# if we're not allowed to use cache, call getgrnam() in all cases.
# if we're allowed to use it; only call getgrnam() if we have no cache for this group
if (!$cache || (!$_cache_getgrnam{$group} || ref $_cache_getgrnam{$group} ne 'ARRAY')) {
$_cache_getgrnam{$group} = [(getgrnam($group))];
}
my ($groupname, $passwd, $gid, $members) = @{$_cache_getgrnam{$group}};
if ($groupname) {
# try to use sys_getent_gr()'s cache if available and allowed by caller.
# we loop through all the system groups to find the proper one
foreach my $gr (@{OVH::Bastion::sys_getent_gr(cache => $cache)->value}) {
next if $gr->{'name'} ne $group;
my (undef, $shortGroup) = $group =~ m{^(key)?(.+)};
return R('OK', value => {group => $group, shortGroup => $shortGroup, gid => $gid, keyhome => "/home/keykeeper/$group", members => [split(/ /, $members)]});
return R(
'OK',
value => {
group => $group,
shortGroup => $shortGroup,
gid => $gr->{'gid'},
keyhome => "/home/keykeeper/$group",
members => $gr->{'members'},
}
);
}
if ($params{'user_friendly_error'}) {
# build a user-compatible error message, as it can make its way through osh_exit()
# build a user-compatible error message if asked to, as it can make its way through osh_exit()
if ($user_friendly_error) {
$group =~ s/^key//;
return R('KO_GROUP_NOT_FOUND', msg => "The bastion group '$group' doesn't exist.\nYou may use groupList --all to see all existing groups.");
}
@ -244,42 +247,52 @@ sub is_account_valid {
return R('ERR_IMPOSSIBLE_CASE');
}
# check that this account is present on the bastion
# it also returns untainted data, including splitting by realm where applicable
my %_cache_getpwnam;
sub is_account_existing {
my %params = @_;
my $account = $params{'account'};
my $checkBastionShell = $params{'checkBastionShell'}; # check if this account is a bastion user
my $cache = $params{'cache'}; # allow cache use to speedup commands that don't modify accounts but may call us extensively, i.e. groupList
my $cache = $params{'cache'}; # allow cache use
if (!$account) {
return R('ERR_MISSING_PARAMETER', msg => "Missing parameter 'account'");
}
# if we're not allowed to use cache, call getpwnam() in all cases.
# if we're allowed to use it; only call getpwnam() if we have no cache for this account
if (!$cache || (!$_cache_getpwnam{$account} || ref $_cache_getpwnam{$account} ne 'ARRAY')) {
$_cache_getpwnam{$account} = [(getpwnam($account))];
}
my ($name, $passwd, $uid, $gid, $quota, $comment, $gcos, $dir, $shell, $expire) = @{$_cache_getpwnam{$account}};
my %entry;
if (OVH::Bastion::is_mocking()) {
($name, $passwd, $uid, $gid, $gcos, $dir, $shell) = OVH::Bastion::mock_get_account_entry(account => $account);
my @fields = OVH::Bastion::mock_get_account_entry(account => $account);
%entry = (
name => $fields[0],
passwd => $fields[1],
uid => $fields[2],
gid => $fields[3],
gcos => $fields[4],
dir => $fields[5],
shell => $fields[6],
);
}
else {
# try to use sys_getent_pw()'s cache if available and allowed by caller.
# we loop through all the system accounts to find the proper one
foreach my $pw (@{OVH::Bastion::sys_getent_pw(cache => $cache)->value}) {
next if $pw->{'name'} ne $account;
%entry = %$pw;
last;
}
}
if ($name) {
my ($newname) = $name =~ m{([a-zA-Z0-9._-]+)};
return R('ERR_SECURITY_VIOLATION', msg => "Forbidden characters in account name") if ($newname ne $name);
$name = $newname; # untaint
if ($checkBastionShell && $shell ne $OVH::Bastion::BASEPATH . "/bin/shell/osh.pl") {
if (%entry) {
my ($newname) = $entry{'name'} =~ m{([a-zA-Z0-9._-]+)};
return R('ERR_SECURITY_VIOLATION', msg => "Forbidden characters in account name") if ($newname ne $entry{'name'});
$entry{'name'} = $newname; # untaint
if ($checkBastionShell && $entry{'shell'} ne $OVH::Bastion::BASEPATH . "/bin/shell/osh.pl") {
return R('KO_NOT_FOUND', msg => "Account '$account' doesn't exist"); # msg is the same as below, voluntarily
}
my ($newdir) = $dir =~ m{([/a-zA-Z0-9._-]+)}; # untaint
return R('ERR_SECURITY_VIOLATION', msg => "Forbidden characters in account home directory") if ($newdir ne $dir);
$dir = $newdir; # untaint
return R('OK', value => {uid => $uid, gid => $gid, dir => $dir, account => $name});
my ($newdir) = $entry{'dir'} =~ m{([/a-zA-Z0-9._-]+)}; # untaint
return R('ERR_SECURITY_VIOLATION', msg => "Forbidden characters in account home directory") if ($newdir ne $entry{'dir'});
$entry{'dir'} = $newdir; # untaint
return R('OK', value => {uid => $entry{'uid'}, gid => $entry{'gid'}, dir => $entry{'dir'}, account => $entry{'name'}});
}
return R('KO_NOT_FOUND', msg => "Account '$account' doesn't exist");
}
@ -722,97 +735,114 @@ sub add_user_to_group {
return R('OK');
}
my %_cache_get_group_list;
# return the list of the bastion groups (i.e. not the system group list)
sub get_group_list {
my %params = @_;
my $groupType = $params{'groupType'};
my $cache = $params{'cache'}; # if true, allow cache use
state $cached_response;
if ($cache and $_cache_get_group_list{$groupType}) {
return $_cache_get_group_list{$groupType};
# if we've been called before and can use the cache, just return it
if ($cache and $cached_response) {
return $cached_response;
}
my %groups;
setgrent();
while (my @nextgroup = getgrent()) {
my ($name, $passwd, $gid, $members) = @nextgroup;
# also be nice and fill this cache for our sibling funcs
$_cache_getgrnam{$name} = \@nextgroup;
if ( $groupType eq 'key'
and $name =~ /^key/
and $name !~ /-(?:owner|gatekeeper|aclkeeper)$/
and not grep { $name eq $_ } qw{ keykeeper keyreader })
# sys_getent_gr() might have been called before, and has its own cache,
# so also try to use its cache if allowed and available.
# we loop through all the system groups and only retain those starting
# with "key", and not finishing in -owner, -gatekeeper or -aclkeeper.
# we also exclude special builtin groups (keykeeper and keyreader)
foreach my $gr (@{OVH::Bastion::sys_getent_gr(cache => $cache)->value}) {
if ( $gr->{'name'} =~ /^key/
&& $gr->{'name'} !~ /-(?:owner|gatekeeper|aclkeeper)$/
&& !grep { $gr->{'name'} eq $_ } qw{ keykeeper keyreader })
{
$name =~ s/^key//;
$groups{$name} = {gid => $gid, members => [split(/ /, $members)]} if ($name ne '');
$gr->{'name'} =~ s/^key//;
$groups{$gr->{'name'}} = {gid => $gr->{'gid'}, members => $gr->{'members'}} if ($gr->{'name'} ne '');
}
}
$_cache_get_group_list{$groupType} = R('OK', value => \%groups);
return $_cache_get_group_list{$groupType};
$cached_response = R('OK', value => \%groups);
return $cached_response;
}
# return the list of bastion accounts (i.e. not the system user list)
sub get_account_list {
my %params = @_;
my $accounts = $params{'accounts'} || [];
my $cache = $params{'cache'}; # if true, allow cache use
state $cached_response;
if ($cache and $cached_response) {
# if we've been called before and can use the cache, just return it
# don't do it if we're asked to only return a subset of all the accounts
if ($cache && $cached_response && !@$accounts) {
return $cached_response;
}
my %users;
if (@$accounts) {
foreach (@$accounts) {
my ($name, $passwd, $uid, $gid, $quota, $comment, $gcos, $dir, $shell, $expire) = getpwnam($_);
next unless OVH::Bastion::is_bastion_account_valid_and_existing(account => $name);
$users{$name} = {name => $name, uid => $uid, gid => $gid, home => $dir, shell => $shell};
# sys_getent_pw() might have been called before, and has its own cache,
# so also try to use its cache if allowed and available.
# we loop through all the accounts known to the OS
foreach my $pw (@{OVH::Bastion::sys_getent_pw(cache => $cache)->value}) {
# if $accounts has been specified, only consider those
next if (@$accounts && !grep { $pw->{'name'} eq $_ } @$accounts);
# skip invalid accounts
next if not OVH::Bastion::is_bastion_account_valid_and_existing(account => $pw->{'name'});
# add proper accounts, only include a subset of the fields we got
$users{$pw->{'name'}} = {name => $pw->{'name'}, gid => $pw->{'gid'}, home => $pw->{'dir'}, shell => $pw->{'shell'}, uid => $pw->{'uid'}};
}
if (@$accounts) {
return R('OK', value => \%users);
}
else {
setpwent();
while (my @nextaccount = getpwent()) {
my ($name, $passwd, $uid, $gid, $quota, $comment, $gcos, $dir, $shell, $expire) = @nextaccount;
# also be nice and fill this cache for our sibling funcs
$_cache_getpwnam{$name} = \@nextaccount;
next unless OVH::Bastion::is_bastion_account_valid_and_existing(account => $name);
$users{$name} = {name => $name, uid => $uid, gid => $gid, home => $dir, shell => $shell};
}
}
$cached_response = R('OK', value => \%users);
return $cached_response;
}
}
sub get_realm_list {
my %params = @_;
my $realms = $params{'realms'} || [];
my $cache = $params{'cache'}; # if true, allow cache use
state $cached_response;
# if we've been called before and can use the cache, just return it
# don't do it if we're asked to only return a subset of all the accounts
if ($cache && $cached_response && !@$realms) {
return $cached_response;
}
my %users;
setpwent();
# sys_getent_pw() might have been called before, and has its own cache,
# so also try to use its cache if allowed and available.
# we loop through all the accounts known to the OS
foreach my $pw (@{OVH::Bastion::sys_getent_pw(cache => $cache)->value}) {
# if $realms has been specified, only consider those
next if (@$realms && !grep { $pw->{'name'} eq "realm_$_" } @$realms);
# skip invalid realms
next if not OVH::Bastion::is_bastion_account_valid_and_existing(account => $pw->{'name'}, accountType => "realm");
# add proper realms
my $name = $pw->{'name'};
$name =~ s{^realm_}{};
$users{$name} = {name => $name};
}
if (@$realms) {
foreach (@$realms) {
my ($name, $passwd, $uid, $gid, $quota, $comment, $gcos, $dir, $shell, $expire) = getpwnam("realm_" . $_);
next unless OVH::Bastion::is_bastion_account_valid_and_existing(account => $name, accountType => "realm");
$name =~ s{^realm_}{};
$users{$name} = {name => $name};
}
return R('OK', value => \%users);
}
else {
setpwent();
while (my ($name, $passwd, $uid, $gid, $quota, $comment, $gcos, $dir, $shell, $expire) = getpwent()) {
next unless OVH::Bastion::is_bastion_account_valid_and_existing(account => $name, accountType => "realm");
$name =~ s{^realm_}{};
$users{$name} = {name => $name};
$cached_response = R('OK', value => \%users);
return $cached_response;
}
}
return R('OK', value => \%users);
}
# check if account is a bastion admin (gives access to adminXyz commands)

View file

@ -595,4 +595,84 @@ sub is_in_path {
return R('KO', msg => "$binary was not found in PATH");
}
# as setpwent/endpwent can have side effects to any getpwent used between
# them, possibly in other parts of the program, encapsulate everything here
# to avoid side effects
sub sys_getent_pw {
my %params = @_;
my $cache = $params{'cache'};
state $cached_response;
if ($cache && $cached_response) {
return $cached_response;
}
my @all;
# end/set: for some reason, if we don't end() before set(), there seem
# to be a cache somewhere, and we get entries that have been
# deleted (milli)seconds before. This behaviour is undocumented, as set()
# is supposed to reset the pointer, and a no mention of a cache is done
# anywhere. Luckily, Prepending the set() with an end() seems to
# reliably fix the issue on all tested OSes.
endpwent();
setpwent();
while (my @line = getpwent()) {
push @all,
{
name => $line[0],
passwd => $line[1],
uid => $line[2],
gid => $line[3],
quota => $line[4],
comment => $line[5],
gcos => $line[6],
dir => $line[7],
shell => $line[8],
expire => $line[9],
};
}
endpwent();
$cached_response = R('OK', value => \@all);
return $cached_response;
}
# as setgrent/endgrent can have side effects to any getgrent used between
# them, possibly in other parts of the program, encapsulate everything here
# to avoid side effects
sub sys_getent_gr {
my %params = @_;
my $cache = $params{'cache'};
state $cached_response;
if ($cache && $cached_response) {
return $cached_response;
}
my @all;
# end/set: for some reason, if we don't end() before set(), there seem
# to be a cache somewhere, and we get entries that have been
# deleted (milli)seconds before. This behaviour is undocumented, as set()
# is supposed to reset the pointer, and a no mention of a cache is done
# anywhere. Luckily, pPrepending the set() with an end() seems to
# reliably fix the issue on all tested OSes.
endgrent();
setgrent();
while (my @line = getgrent()) {
push @all,
{
name => $line[0],
passwd => $line[1],
gid => $line[2],
members => [split(/ /, $line[3])],
};
}
endgrent();
$cached_response = R('OK', value => \@all);
return $cached_response;
}
1;