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author | Maciej Krüger <mkg20001@gmail.com> | 2023-09-21 14:56:40 +0200 |
---|---|---|
committer | Maciej Krüger <mkg20001@gmail.com> | 2023-09-22 15:13:56 +0200 |
commit | 57d41f97514d95fa6e4dcb73885e6af3a50209be (patch) | |
tree | a13363d2f82daa64f95a9e8309325a1149a4647f /nixos | |
parent | 4d94b454d96c7e07bf500768037176aca2c13a21 (diff) | |
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nixos/sudo: revert sudo-rs 922926cfbc08f3e4065b51a41ebf613e59888015 (partial #253876)
This reverts the module changes that were added by the addition of sudo-rs (merge 922926cfbc08f3e4065b51a41ebf613e59888015) from the sudo module. Individual commits reverted: * 409d29ca7373 2023-08-31 | [nicoo] nixos/sudo: Split up `configFile` into individual sections * 454151375d62 2023-09-04 | [nicoo] nixos/sudo: Don't include empty sections * 8742134c8053 2023-09-04 | [nicoo] nixos/sudo: Only keep SSH_AUTH_SOCK if used for authentication * f5aadb56bed0 2023-09-07 | [nicoo] nixos/sudo: Refactor option definitions * 8b9e867ac83f 2023-09-07 | [nicoo] nixos/sudo: Refactor checks for Todd C. Miller's implemetation * 3a95964fd5ba 2023-09-07 | [nicoo] nixos/sudo: Drop useless `lib.` qualifiers * b1eab8ca53dc 2023-09-07 | [nicoo] nixos/sudo: Handle `root`'s default rule through `extraRules` * 717e51a140d6 2023-09-07 | [nicoo] nixos/sudo: Make the default rules' options configurable * c11da3911787 2023-09-07 | [nicoo] nixos/sudo: Drop the sudoers comment for `extraRules` * f0107b4f63a7 2023-09-07 | [nicoo] nixos/sudo: Check syntax using the configured package * 914bf5836974 2023-09-07 | [nicoo] nixos/{sudo, terminfo}: Adjust defaults for compatibility with `sudo-rs` * f66eb0df3b23 2023-09-07 | [nicoo] nixos/sudo: Only wrap `sudoedit` when using Miller's sudo * d63eb55e81ad 2023-09-13 | [nicoo] nixos/sudo: Generate `sudo-i` PAM config for interactive use of `sudo-rs` * d8d0b8019ff3 2023-09-13 | [nicoo] nixos/sudo: Add myself as maintainer (nbraud/nixos/sudo-rs)
Diffstat (limited to 'nixos')
-rw-r--r-- | nixos/modules/security/sudo-rs.nix | 296 | ||||
-rw-r--r-- | nixos/modules/security/sudo.nix | 169 |
2 files changed, 367 insertions, 98 deletions
diff --git a/nixos/modules/security/sudo-rs.nix b/nixos/modules/security/sudo-rs.nix new file mode 100644 index 000000000000..4bdbe9671e6d --- /dev/null +++ b/nixos/modules/security/sudo-rs.nix @@ -0,0 +1,296 @@ +{ config, lib, pkgs, ... }: + +with lib; + +let + + inherit (pkgs) sudo sudo-rs; + + cfg = config.security.sudo; + + enableSSHAgentAuth = + with config.security; + pam.enableSSHAgentAuth && pam.sudo.sshAgentAuth; + + usingMillersSudo = cfg.package.pname == sudo.pname; + usingSudoRs = cfg.package.pname == sudo-rs.pname; + + toUserString = user: if (isInt user) then "#${toString user}" else "${user}"; + toGroupString = group: if (isInt group) then "%#${toString group}" else "%${group}"; + + toCommandOptionsString = options: + "${concatStringsSep ":" options}${optionalString (length options != 0) ":"} "; + + toCommandsString = commands: + concatStringsSep ", " ( + map (command: + if (isString command) then + command + else + "${toCommandOptionsString command.options}${command.command}" + ) commands + ); + +in + +{ + + ###### interface + + options.security.sudo = { + + defaultOptions = mkOption { + type = with types; listOf str; + default = optional usingMillersSudo "SETENV"; + defaultText = literalMD '' + `[ "SETENV" ]` if using the default `sudo` implementation + ''; + description = mdDoc '' + Options used for the default rules, granting `root` and the + `wheel` group permission to run any command as any user. + ''; + }; + + enable = mkOption { + type = types.bool; + default = true; + description = mdDoc '' + Whether to enable the {command}`sudo` command, which + allows non-root users to execute commands as root. + ''; + }; + + package = mkOption { + type = types.package; + default = pkgs.sudo; + defaultText = literalExpression "pkgs.sudo"; + description = mdDoc '' + Which package to use for `sudo`. + ''; + }; + + wheelNeedsPassword = mkOption { + type = types.bool; + default = true; + description = mdDoc '' + Whether users of the `wheel` group must + provide a password to run commands as super user via {command}`sudo`. + ''; + }; + + execWheelOnly = mkOption { + type = types.bool; + default = false; + description = mdDoc '' + 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 = mkOption { + type = types.lines; + # Note: if syntax errors are detected in this file, the NixOS + # configuration will fail to build. + description = mdDoc '' + This string contains the contents of the + {file}`sudoers` file. + ''; + }; + + extraRules = mkOption { + description = mdDoc '' + 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 mkBefore/mkAfter to ensure + this is the case when configuration options are merged. + ''; + default = []; + example = 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 types; listOf (submodule { + options = { + users = mkOption { + type = with types; listOf (either str int); + description = mdDoc '' + The usernames / UIDs this rule should apply for. + ''; + default = []; + }; + + groups = mkOption { + type = with types; listOf (either str int); + description = mdDoc '' + The groups / GIDs this rule should apply for. + ''; + default = []; + }; + + host = mkOption { + type = types.str; + default = "ALL"; + description = mdDoc '' + For what host this rule should apply. + ''; + }; + + runAs = mkOption { + type = with types; str; + default = "ALL:ALL"; + description = mdDoc '' + 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 = mkOption { + description = mdDoc '' + The commands for which the rule should apply. + ''; + type = with types; listOf (either str (submodule { + + options = { + command = mkOption { + type = with types; str; + description = mdDoc '' + 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 = mkOption { + type = with types; listOf (enum [ "NOPASSWD" "PASSWD" "NOEXEC" "EXEC" "SETENV" "NOSETENV" "LOG_INPUT" "NOLOG_INPUT" "LOG_OUTPUT" "NOLOG_OUTPUT" ]); + description = mdDoc '' + Options for running the command. Refer to the [sudo manual](https://www.sudo.ws/man/1.7.10/sudoers.man.html). + ''; + default = []; + }; + }; + + })); + }; + }; + }); + }; + + extraConfig = mkOption { + type = types.lines; + default = ""; + description = mdDoc '' + Extra configuration text appended to {file}`sudoers`. + ''; + }; + }; + + + ###### implementation + + config = mkIf cfg.enable { + security.sudo.extraRules = + let + defaultRule = { users ? [], groups ? [], opts ? [] }: [ { + inherit users groups; + commands = [ { + command = "ALL"; + options = opts ++ cfg.defaultOptions; + } ]; + } ]; + in mkMerge [ + # This is ordered before users' `mkBefore` rules, + # so as not to introduce unexpected changes. + (mkOrder 400 (defaultRule { users = [ "root" ]; })) + + # This is ordered to show before (most) other rules, but + # late-enough for a user to `mkBefore` it. + (mkOrder 600 (defaultRule { + groups = [ "wheel" ]; + opts = (optional (!cfg.wheelNeedsPassword) "NOPASSWD"); + })) + ]; + + security.sudo.configFile = concatStringsSep "\n" (filter (s: s != "") [ + '' + # Don't edit this file. Set the NixOS options ‘security.sudo.configFile’ + # or ‘security.sudo.extraRules’ instead. + '' + (optionalString enableSSHAgentAuth '' + # Keep SSH_AUTH_SOCK so that pam_ssh_agent_auth.so can do its magic. + Defaults env_keep+=SSH_AUTH_SOCK + '') + (concatStringsSep "\n" ( + lists.flatten ( + map ( + rule: optionals (length rule.commands != 0) [ + (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) + ] + ) cfg.extraRules + ) + ) + "\n") + (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; + }; + # sudo-rs does not yet ship a sudoedit (as of v0.2.0) + sudoedit = mkIf usingMillersSudo { + source = "${cfg.package.out}/bin/sudoedit"; + inherit owner group setuid permissions; + }; + }; + + environment.systemPackages = [ sudo ]; + + security.pam.services.sudo = { sshAgentAuth = true; usshAuth = true; }; + security.pam.services.sudo-i = mkIf usingSudoRs + { sshAgentAuth = true; usshAuth = true; }; + + environment.etc.sudoers = + { source = + pkgs.runCommand "sudoers" + { + src = pkgs.writeText "sudoers-in" cfg.configFile; + preferLocalBuild = true; + } + "${cfg.package}/bin/visudo -f $src -c && cp $src $out"; + mode = "0440"; + }; + + }; + + meta.maintainers = [ lib.maintainers.nicoo ]; + +} diff --git a/nixos/modules/security/sudo.nix b/nixos/modules/security/sudo.nix index 4bdbe9671e6d..d225442773c6 100644 --- a/nixos/modules/security/sudo.nix +++ b/nixos/modules/security/sudo.nix @@ -4,16 +4,9 @@ with lib; let - inherit (pkgs) sudo sudo-rs; - cfg = config.security.sudo; - enableSSHAgentAuth = - with config.security; - pam.enableSSHAgentAuth && pam.sudo.sshAgentAuth; - - usingMillersSudo = cfg.package.pname == sudo.pname; - usingSudoRs = cfg.package.pname == sudo-rs.pname; + inherit (pkgs) sudo; toUserString = user: if (isInt user) then "#${toString user}" else "${user}"; toGroupString = group: if (isInt group) then "%#${toString group}" else "%${group}"; @@ -37,51 +30,41 @@ in ###### interface - options.security.sudo = { - - defaultOptions = mkOption { - type = with types; listOf str; - default = optional usingMillersSudo "SETENV"; - defaultText = literalMD '' - `[ "SETENV" ]` if using the default `sudo` implementation - ''; - description = mdDoc '' - Options used for the default rules, granting `root` and the - `wheel` group permission to run any command as any user. - ''; - }; + options = { - enable = mkOption { + security.sudo.enable = mkOption { type = types.bool; default = true; - description = mdDoc '' - Whether to enable the {command}`sudo` command, which - allows non-root users to execute commands as root. - ''; + description = + lib.mdDoc '' + Whether to enable the {command}`sudo` command, which + allows non-root users to execute commands as root. + ''; }; - package = mkOption { + security.sudo.package = mkOption { type = types.package; default = pkgs.sudo; defaultText = literalExpression "pkgs.sudo"; - description = mdDoc '' + description = lib.mdDoc '' Which package to use for `sudo`. ''; }; - wheelNeedsPassword = mkOption { + security.sudo.wheelNeedsPassword = mkOption { type = types.bool; default = true; - description = mdDoc '' - Whether users of the `wheel` group must - provide a password to run commands as super user via {command}`sudo`. - ''; + description = + lib.mdDoc '' + Whether users of the `wheel` group must + provide a password to run commands as super user via {command}`sudo`. + ''; }; - execWheelOnly = mkOption { + security.sudo.execWheelOnly = mkOption { type = types.bool; default = false; - description = mdDoc '' + description = lib.mdDoc '' 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 @@ -89,18 +72,19 @@ in ''; }; - configFile = mkOption { + security.sudo.configFile = mkOption { type = types.lines; # Note: if syntax errors are detected in this file, the NixOS # configuration will fail to build. - description = mdDoc '' - This string contains the contents of the - {file}`sudoers` file. - ''; + description = + lib.mdDoc '' + This string contains the contents of the + {file}`sudoers` file. + ''; }; - extraRules = mkOption { - description = mdDoc '' + security.sudo.extraRules = mkOption { + description = lib.mdDoc '' 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 mkBefore/mkAfter to ensure @@ -130,7 +114,7 @@ in options = { users = mkOption { type = with types; listOf (either str int); - description = mdDoc '' + description = lib.mdDoc '' The usernames / UIDs this rule should apply for. ''; default = []; @@ -138,7 +122,7 @@ in groups = mkOption { type = with types; listOf (either str int); - description = mdDoc '' + description = lib.mdDoc '' The groups / GIDs this rule should apply for. ''; default = []; @@ -147,7 +131,7 @@ in host = mkOption { type = types.str; default = "ALL"; - description = mdDoc '' + description = lib.mdDoc '' For what host this rule should apply. ''; }; @@ -155,7 +139,7 @@ in runAs = mkOption { type = with types; str; default = "ALL:ALL"; - description = mdDoc '' + description = lib.mdDoc '' Under which user/group the specified command is allowed to run. A user can be specified using just the username: `"foo"`. @@ -165,7 +149,7 @@ in }; commands = mkOption { - description = mdDoc '' + description = lib.mdDoc '' The commands for which the rule should apply. ''; type = with types; listOf (either str (submodule { @@ -173,7 +157,7 @@ in options = { command = mkOption { type = with types; str; - description = mdDoc '' + description = lib.mdDoc '' 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. @@ -182,7 +166,7 @@ in options = mkOption { type = with types; listOf (enum [ "NOPASSWD" "PASSWD" "NOEXEC" "EXEC" "SETENV" "NOSETENV" "LOG_INPUT" "NOLOG_INPUT" "LOG_OUTPUT" "NOLOG_OUTPUT" ]); - description = mdDoc '' + description = lib.mdDoc '' Options for running the command. Refer to the [sudo manual](https://www.sudo.ws/man/1.7.10/sudoers.man.html). ''; default = []; @@ -195,10 +179,10 @@ in }); }; - extraConfig = mkOption { + security.sudo.extraConfig = mkOption { type = types.lines; default = ""; - description = mdDoc '' + description = lib.mdDoc '' Extra configuration text appended to {file}`sudoers`. ''; }; @@ -208,52 +192,44 @@ in ###### implementation config = mkIf cfg.enable { - security.sudo.extraRules = - let - defaultRule = { users ? [], groups ? [], opts ? [] }: [ { - inherit users groups; - commands = [ { - command = "ALL"; - options = opts ++ cfg.defaultOptions; - } ]; - } ]; - in mkMerge [ - # This is ordered before users' `mkBefore` rules, - # so as not to introduce unexpected changes. - (mkOrder 400 (defaultRule { users = [ "root" ]; })) - - # This is ordered to show before (most) other rules, but - # late-enough for a user to `mkBefore` it. - (mkOrder 600 (defaultRule { - groups = [ "wheel" ]; - opts = (optional (!cfg.wheelNeedsPassword) "NOPASSWD"); - })) - ]; - - security.sudo.configFile = concatStringsSep "\n" (filter (s: s != "") [ + assertions = [ + { assertion = cfg.package.pname != "sudo-rs"; + message = "The NixOS `sudo` module does not work with `sudo-rs` yet."; } + ]; + + # We `mkOrder 600` so that the default rule shows up first, but there is + # still enough room for a user to `mkBefore` it. + security.sudo.extraRules = mkOrder 600 [ + { groups = [ "wheel" ]; + commands = [ { command = "ALL"; options = (if cfg.wheelNeedsPassword then [ "SETENV" ] else [ "NOPASSWD" "SETENV" ]); } ]; + } + ]; + + security.sudo.configFile = '' # Don't edit this file. Set the NixOS options ‘security.sudo.configFile’ # or ‘security.sudo.extraRules’ instead. - '' - (optionalString enableSSHAgentAuth '' + # Keep SSH_AUTH_SOCK so that pam_ssh_agent_auth.so can do its magic. Defaults env_keep+=SSH_AUTH_SOCK - '') - (concatStringsSep "\n" ( - lists.flatten ( - map ( - rule: optionals (length rule.commands != 0) [ - (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) - ] - ) cfg.extraRules - ) - ) + "\n") - (optionalString (cfg.extraConfig != "") '' - # extraConfig + + # "root" is allowed to do anything. + root ALL=(ALL:ALL) SETENV: ALL + + # extraRules + ${concatStringsSep "\n" ( + lists.flatten ( + map ( + rule: optionals (length rule.commands != 0) [ + (map (user: "${toUserString user} ${rule.host}=(${rule.runAs}) ${toCommandsString rule.commands}") rule.users) + (map (group: "${toGroupString group} ${rule.host}=(${rule.runAs}) ${toCommandsString rule.commands}") rule.groups) + ] + ) cfg.extraRules + ) + )} + ${cfg.extraConfig} - '') - ]); + ''; security.wrappers = let owner = "root"; @@ -265,8 +241,7 @@ in source = "${cfg.package.out}/bin/sudo"; inherit owner group setuid permissions; }; - # sudo-rs does not yet ship a sudoedit (as of v0.2.0) - sudoedit = mkIf usingMillersSudo { + sudoedit = { source = "${cfg.package.out}/bin/sudoedit"; inherit owner group setuid permissions; }; @@ -275,8 +250,6 @@ in environment.systemPackages = [ sudo ]; security.pam.services.sudo = { sshAgentAuth = true; usshAuth = true; }; - security.pam.services.sudo-i = mkIf usingSudoRs - { sshAgentAuth = true; usshAuth = true; }; environment.etc.sudoers = { source = @@ -285,12 +258,12 @@ in src = pkgs.writeText "sudoers-in" cfg.configFile; preferLocalBuild = true; } - "${cfg.package}/bin/visudo -f $src -c && cp $src $out"; + # Make sure that the sudoers file is syntactically valid. + # (currently disabled - NIXOS-66) + "${pkgs.buildPackages.sudo}/sbin/visudo -f $src -c && cp $src $out"; mode = "0440"; }; }; - meta.maintainers = [ lib.maintainers.nicoo ]; - } |