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|
{ pkgs, ... }:
let
userUid = 1000;
usersGid = 100;
busybox =
pkgs:
pkgs.busybox.override {
# Without this, the busybox binary drops euid to ruid for most applets, including id.
# See https://bugs.busybox.net/show_bug.cgi?id=15101
extraConfig = "CONFIG_FEATURE_SUID n";
};
in
{
name = "wrappers";
nodes.machine =
{ config, pkgs, ... }:
{
ids.gids.users = usersGid;
users.users = {
regular = {
uid = userUid;
isNormalUser = true;
};
};
security.apparmor.enable = true;
security.wrappers = {
disabled = {
enable = false;
owner = "root";
group = "root";
setuid = true;
source = "${busybox pkgs}/bin/busybox";
program = "disabled_busybox";
};
suidRoot = {
owner = "root";
group = "root";
setuid = true;
source = "${busybox pkgs}/bin/busybox";
program = "suid_root_busybox";
};
sgidRoot = {
owner = "root";
group = "root";
setgid = true;
source = "${busybox pkgs}/bin/busybox";
program = "sgid_root_busybox";
};
withChown = {
owner = "root";
group = "root";
source = "${pkgs.libcap}/bin/capsh";
program = "capsh_with_chown";
capabilities = "cap_chown+ep";
};
};
};
testScript = ''
def cmd_as_regular(cmd):
return "su -l regular -c '{0}'".format(cmd)
def test_as_regular(cmd, expected):
out = machine.succeed(cmd_as_regular(cmd)).strip()
assert out == expected, "Expected {0} to output {1}, but got {2}".format(cmd, expected, out)
def test_as_regular_in_userns_mapped_as_root(cmd, expected):
out = machine.succeed(f"su -l regular -c '${pkgs.util-linux}/bin/unshare -rm {cmd}'").strip()
assert out == expected, "Expected {0} to output {1}, but got {2}".format(cmd, expected, out)
test_as_regular('${busybox pkgs}/bin/busybox id -u', '${toString userUid}')
test_as_regular('${busybox pkgs}/bin/busybox id -ru', '${toString userUid}')
test_as_regular('${busybox pkgs}/bin/busybox id -g', '${toString usersGid}')
test_as_regular('${busybox pkgs}/bin/busybox id -rg', '${toString usersGid}')
test_as_regular('/run/wrappers/bin/suid_root_busybox id -u', '0')
test_as_regular('/run/wrappers/bin/suid_root_busybox id -ru', '${toString userUid}')
test_as_regular('/run/wrappers/bin/suid_root_busybox id -g', '${toString usersGid}')
test_as_regular('/run/wrappers/bin/suid_root_busybox id -rg', '${toString usersGid}')
test_as_regular('/run/wrappers/bin/sgid_root_busybox id -u', '${toString userUid}')
test_as_regular('/run/wrappers/bin/sgid_root_busybox id -ru', '${toString userUid}')
test_as_regular('/run/wrappers/bin/sgid_root_busybox id -g', '0')
test_as_regular('/run/wrappers/bin/sgid_root_busybox id -rg', '${toString usersGid}')
test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/suid_root_busybox id -u', '0')
test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/suid_root_busybox id -ru', '0')
test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/suid_root_busybox id -g', '0')
test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/suid_root_busybox id -rg', '0')
test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/sgid_root_busybox id -u', '0')
test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/sgid_root_busybox id -ru', '0')
test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/sgid_root_busybox id -g', '0')
test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/sgid_root_busybox id -rg', '0')
# Test that in nonewprivs environment the wrappers simply exec their target.
test_as_regular('${pkgs.util-linux}/bin/setpriv --no-new-privs /run/wrappers/bin/suid_root_busybox id -u', '${toString userUid}')
test_as_regular('${pkgs.util-linux}/bin/setpriv --no-new-privs /run/wrappers/bin/suid_root_busybox id -ru', '${toString userUid}')
test_as_regular('${pkgs.util-linux}/bin/setpriv --no-new-privs /run/wrappers/bin/suid_root_busybox id -g', '${toString usersGid}')
test_as_regular('${pkgs.util-linux}/bin/setpriv --no-new-privs /run/wrappers/bin/suid_root_busybox id -rg', '${toString usersGid}')
test_as_regular('${pkgs.util-linux}/bin/setpriv --no-new-privs /run/wrappers/bin/sgid_root_busybox id -u', '${toString userUid}')
test_as_regular('${pkgs.util-linux}/bin/setpriv --no-new-privs /run/wrappers/bin/sgid_root_busybox id -ru', '${toString userUid}')
test_as_regular('${pkgs.util-linux}/bin/setpriv --no-new-privs /run/wrappers/bin/sgid_root_busybox id -g', '${toString usersGid}')
test_as_regular('${pkgs.util-linux}/bin/setpriv --no-new-privs /run/wrappers/bin/sgid_root_busybox id -rg', '${toString usersGid}')
# We are only testing the permitted set, because it's easiest to look at with capsh.
machine.fail(cmd_as_regular('${pkgs.libcap}/bin/capsh --has-p=CAP_CHOWN'))
machine.fail(cmd_as_regular('${pkgs.libcap}/bin/capsh --has-p=CAP_SYS_ADMIN'))
machine.succeed(cmd_as_regular('/run/wrappers/bin/capsh_with_chown --has-p=CAP_CHOWN'))
machine.fail(cmd_as_regular('/run/wrappers/bin/capsh_with_chown --has-p=CAP_SYS_ADMIN'))
# Test that the only user of apparmor policy includes generated by
# wrappers works. Ideally this'd be located in a test for the module that
# actually makes the apparmor policy for ping, but there's no convenient
# test for that one.
machine.succeed("ping -c 1 127.0.0.1")
# Test that the disabled wrapper is not present.
machine.fail("test -e /run/wrappers/bin/disabled_busybox")
'';
}
|
