nixpkgs/nixos/modules/security/sudo-rs.nix
Silvan Mosberger 4f0dadbf38 treewide: format all inactive Nix files
After final improvements to the official formatter implementation,
this commit now performs the first treewide reformat of Nix files using it.
This is part of the implementation of RFC 166.

Only "inactive" files are reformatted, meaning only files that
aren't being touched by any PR with activity in the past 2 months.
This is to avoid conflicts for PRs that might soon be merged.
Later we can do a full treewide reformat to get the rest,
which should not cause as many conflicts.

A CI check has already been running for some time to ensure that new and
already-formatted files are formatted, so the files being reformatted here
should also stay formatted.

This commit was automatically created and can be verified using

    nix-build a08b3a4d19.tar.gz \
      --argstr baseRev b32a094368
    result/bin/apply-formatting $NIXPKGS_PATH
2024-12-10 20:26:33 +01:00

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{
config,
lib,
pkgs,
...
}:
let
cfg = config.security.sudo-rs;
toUserString = user: if (lib.isInt user) then "#${toString user}" else "${user}";
toGroupString = group: if (lib.isInt group) then "%#${toString group}" else "%${group}";
toCommandOptionsString =
options: "${lib.concatStringsSep ":" options}${lib.optionalString (lib.length options != 0) ":"} ";
toCommandsString =
commands:
lib.concatStringsSep ", " (
map (
command:
if (lib.isString command) then
command
else
"${toCommandOptionsString command.options}${command.command}"
) commands
);
in
{
###### interface
options.security.sudo-rs = {
defaultOptions = lib.mkOption {
type = with lib.types; listOf str;
default = [ ];
description = ''
Options used for the default rules, granting `root` and the
`wheel` group permission to run any command as any user.
'';
};
enable = lib.mkEnableOption ''
a memory-safe implementation of the {command}`sudo` command,
which allows non-root users to execute commands as root
'';
package = lib.mkPackageOption pkgs "sudo-rs" { };
wheelNeedsPassword = lib.mkOption {
type = lib.types.bool;
default = true;
description = ''
Whether users of the `wheel` group must
provide a password to run commands as super user via {command}`sudo`.
'';
};
execWheelOnly = lib.mkOption {
type = lib.types.bool;
default = false;
description = ''
Only allow members of the `wheel` group to execute sudo by
setting the executable's permissions accordingly.
This prevents users that are not members of `wheel` from
exploiting vulnerabilities in sudo such as CVE-2021-3156.
'';
};
configFile = lib.mkOption {
type = lib.types.lines;
# Note: if syntax errors are detected in this file, the NixOS
# configuration will fail to build.
description = ''
This string contains the contents of the
{file}`sudoers` file.
'';
};
extraRules = lib.mkOption {
description = ''
Define specific rules to be in the {file}`sudoers` file.
More specific rules should come after more general ones in order to
yield the expected behavior. You can use `lib.mkBefore`/`lib.mkAfter` to ensure
this is the case when configuration options are merged.
'';
default = [ ];
example = lib.literalExpression ''
[
# Allow execution of any command by all users in group sudo,
# requiring a password.
{ groups = [ "sudo" ]; commands = [ "ALL" ]; }
# Allow execution of "/home/root/secret.sh" by user `backup`, `database`
# and the group with GID `1006` without a password.
{ users = [ "backup" "database" ]; groups = [ 1006 ];
commands = [ { command = "/home/root/secret.sh"; options = [ "SETENV" "NOPASSWD" ]; } ]; }
# Allow all users of group `bar` to run two executables as user `foo`
# with arguments being pre-set.
{ groups = [ "bar" ]; runAs = "foo";
commands =
[ "/home/baz/cmd1.sh hello-sudo"
{ command = '''/home/baz/cmd2.sh ""'''; options = [ "SETENV" ]; } ]; }
]
'';
type =
with lib.types;
listOf (submodule {
options = {
users = lib.mkOption {
type = with lib.types; listOf (either str int);
description = ''
The usernames / UIDs this rule should apply for.
'';
default = [ ];
};
groups = lib.mkOption {
type = with lib.types; listOf (either str int);
description = ''
The groups / GIDs this rule should apply for.
'';
default = [ ];
};
host = lib.mkOption {
type = lib.types.str;
default = "ALL";
description = ''
For what host this rule should apply.
'';
};
runAs = lib.mkOption {
type = with lib.types; str;
default = "ALL:ALL";
description = ''
Under which user/group the specified command is allowed to run.
A user can be specified using just the username: `"foo"`.
It is also possible to specify a user/group combination using `"foo:bar"`
or to only allow running as a specific group with `":bar"`.
'';
};
commands = lib.mkOption {
description = ''
The commands for which the rule should apply.
'';
type =
with lib.types;
listOf (
either str (submodule {
options = {
command = lib.mkOption {
type = with lib.types; str;
description = ''
A command being either just a path to a binary to allow any arguments,
the full command with arguments pre-set or with `""` used as the argument,
not allowing arguments to the command at all.
'';
};
options = lib.mkOption {
type =
with lib.types;
listOf (enum [
"NOPASSWD"
"PASSWD"
"NOEXEC"
"EXEC"
"SETENV"
"NOSETENV"
"LOG_INPUT"
"NOLOG_INPUT"
"LOG_OUTPUT"
"NOLOG_OUTPUT"
]);
description = ''
Options for running the command. Refer to the [sudo manual](https://www.sudo.ws/man/1.7.10/sudoers.man.html).
'';
default = [ ];
};
};
})
);
};
};
});
};
extraConfig = lib.mkOption {
type = lib.types.lines;
default = "";
description = ''
Extra configuration text appended to {file}`sudoers`.
'';
};
};
###### implementation
config = lib.mkIf cfg.enable {
assertions = [
{
assertion = !config.security.sudo.enable;
message = "`security.sudo` and `security.sudo-rs` cannot both be enabled";
}
];
security.sudo.enable = lib.mkDefault false;
security.sudo-rs.extraRules =
let
defaultRule =
{
users ? [ ],
groups ? [ ],
opts ? [ ],
}:
[
{
inherit users groups;
commands = [
{
command = "ALL";
options = opts ++ cfg.defaultOptions;
}
];
}
];
in
lib.mkMerge [
# This is ordered before users' `lib.mkBefore` rules,
# so as not to introduce unexpected changes.
(lib.mkOrder 400 (defaultRule {
users = [ "root" ];
}))
# This is ordered to show before (most) other rules, but
# late-enough for a user to `lib.mkBefore` it.
(lib.mkOrder 600 (defaultRule {
groups = [ "wheel" ];
opts = (lib.optional (!cfg.wheelNeedsPassword) "NOPASSWD");
}))
];
security.sudo-rs.configFile = lib.concatStringsSep "\n" (
lib.filter (s: s != "") [
''
# Don't edit this file. Set the NixOS options security.sudo-rs.configFile
# or security.sudo-rs.extraRules instead.
''
(lib.pipe cfg.extraRules [
(lib.filter (rule: lib.length rule.commands != 0))
(map (rule: [
(map (
user: "${toUserString user} ${rule.host}=(${rule.runAs}) ${toCommandsString rule.commands}"
) rule.users)
(map (
group: "${toGroupString group} ${rule.host}=(${rule.runAs}) ${toCommandsString rule.commands}"
) rule.groups)
]))
lib.flatten
(lib.concatStringsSep "\n")
])
"\n"
(lib.optionalString (cfg.extraConfig != "") ''
# extraConfig
${cfg.extraConfig}
'')
]
);
security.wrappers =
let
owner = "root";
group = if cfg.execWheelOnly then "wheel" else "root";
setuid = true;
permissions = if cfg.execWheelOnly then "u+rx,g+x" else "u+rx,g+x,o+x";
in
{
sudo = {
source = "${cfg.package.out}/bin/sudo";
inherit
owner
group
setuid
permissions
;
};
};
environment.systemPackages = [ cfg.package ];
security.pam.services.sudo = {
sshAgentAuth = true;
usshAuth = true;
};
security.pam.services.sudo-i = {
sshAgentAuth = true;
usshAuth = true;
};
environment.etc.sudoers = {
source = pkgs.runCommand "sudoers" {
src = pkgs.writeText "sudoers-in" cfg.configFile;
preferLocalBuild = true;
} "${pkgs.buildPackages.sudo-rs}/bin/visudo -f $src -c && cp $src $out";
mode = "0440";
};
};
meta.maintainers = [ lib.maintainers.nicoo ];
}