100 lines
4.3 KiB
Nix
100 lines
4.3 KiB
Nix
import ./make-test-python.nix ({ pkgs, ... }:
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let
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userUid = 1000;
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usersGid = 100;
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busybox = pkgs : pkgs.busybox.override {
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# Without this, the busybox binary drops euid to ruid for most applets, including id.
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# See https://bugs.busybox.net/show_bug.cgi?id=15101
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extraConfig = "CONFIG_FEATURE_SUID n";
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};
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in
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{
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name = "wrappers";
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nodes.machine = { config, pkgs, ... }: {
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ids.gids.users = usersGid;
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users.users = {
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regular = {
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uid = userUid;
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isNormalUser = true;
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};
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};
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security.wrappers = {
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suidRoot = {
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owner = "root";
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group = "root";
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setuid = true;
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source = "${busybox pkgs}/bin/busybox";
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program = "suid_root_busybox";
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};
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sgidRoot = {
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owner = "root";
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group = "root";
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setgid = true;
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source = "${busybox pkgs}/bin/busybox";
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program = "sgid_root_busybox";
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};
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withChown = {
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owner = "root";
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group = "root";
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source = "${pkgs.libcap}/bin/capsh";
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program = "capsh_with_chown";
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capabilities = "cap_chown+ep";
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};
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};
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};
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testScript =
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''
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def cmd_as_regular(cmd):
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return "su -l regular -c '{0}'".format(cmd)
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def test_as_regular(cmd, expected):
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out = machine.succeed(cmd_as_regular(cmd)).strip()
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assert out == expected, "Expected {0} to output {1}, but got {2}".format(cmd, expected, out)
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def test_as_regular_in_userns_mapped_as_root(cmd, expected):
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out = machine.succeed(f"su -l regular -c '${pkgs.util-linux}/bin/unshare -rm {cmd}'").strip()
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assert out == expected, "Expected {0} to output {1}, but got {2}".format(cmd, expected, out)
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test_as_regular('${busybox pkgs}/bin/busybox id -u', '${toString userUid}')
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test_as_regular('${busybox pkgs}/bin/busybox id -ru', '${toString userUid}')
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test_as_regular('${busybox pkgs}/bin/busybox id -g', '${toString usersGid}')
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test_as_regular('${busybox pkgs}/bin/busybox id -rg', '${toString usersGid}')
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test_as_regular('/run/wrappers/bin/suid_root_busybox id -u', '0')
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test_as_regular('/run/wrappers/bin/suid_root_busybox id -ru', '${toString userUid}')
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test_as_regular('/run/wrappers/bin/suid_root_busybox id -g', '${toString usersGid}')
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test_as_regular('/run/wrappers/bin/suid_root_busybox id -rg', '${toString usersGid}')
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test_as_regular('/run/wrappers/bin/sgid_root_busybox id -u', '${toString userUid}')
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test_as_regular('/run/wrappers/bin/sgid_root_busybox id -ru', '${toString userUid}')
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test_as_regular('/run/wrappers/bin/sgid_root_busybox id -g', '0')
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test_as_regular('/run/wrappers/bin/sgid_root_busybox id -rg', '${toString usersGid}')
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test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/suid_root_busybox id -u', '0')
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test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/suid_root_busybox id -ru', '0')
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test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/suid_root_busybox id -g', '0')
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test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/suid_root_busybox id -rg', '0')
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test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/sgid_root_busybox id -u', '0')
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test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/sgid_root_busybox id -ru', '0')
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test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/sgid_root_busybox id -g', '0')
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test_as_regular_in_userns_mapped_as_root('/run/wrappers/bin/sgid_root_busybox id -rg', '0')
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# We are only testing the permitted set, because it's easiest to look at with capsh.
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machine.fail(cmd_as_regular('${pkgs.libcap}/bin/capsh --has-p=CAP_CHOWN'))
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machine.fail(cmd_as_regular('${pkgs.libcap}/bin/capsh --has-p=CAP_SYS_ADMIN'))
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machine.succeed(cmd_as_regular('/run/wrappers/bin/capsh_with_chown --has-p=CAP_CHOWN'))
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machine.fail(cmd_as_regular('/run/wrappers/bin/capsh_with_chown --has-p=CAP_SYS_ADMIN'))
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# test a few "attacks" against which the wrapper protects itself
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machine.succeed("cp /run/wrappers/bin/suid_root_busybox{,.real} /tmp/")
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machine.fail(cmd_as_regular("/tmp/suid_root_busybox id -u"))
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machine.succeed("chmod u+s,a+w /run/wrappers/bin/suid_root_busybox")
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machine.fail(cmd_as_regular("/run/wrappers/bin/suid_root_busybox id -u"))
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'';
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})
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