nixos/users-groups: check format of passwd entries

Things will get quite broken if an /etc/passwd entry contains a
colon (which terminates a field), or a newline (which terminates a
record).  I know because I just accidentally made a user whose home
directory path contained a newline!

So let's make sure that can't happen.
This commit is contained in:
Alyssa Ross 2021-04-20 11:53:24 +00:00
parent d0a6d3b834
commit 9e400a8b93

View file

@ -6,6 +6,12 @@ let
ids = config.ids;
cfg = config.users;
isPasswdCompatible = str: !(hasInfix ":" str || hasInfix "\n" str);
passwdEntry = type: lib.types.addCheck type isPasswdCompatible // {
name = "passwdEntry ${type.name}";
description = "${type.description}, not containing newlines or colons";
};
# Check whether a password hash will allow login.
allowsLogin = hash:
hash == "" # login without password
@ -54,7 +60,7 @@ let
options = {
name = mkOption {
type = types.str;
type = passwdEntry types.str;
apply = x: assert (builtins.stringLength x < 32 || abort "Username '${x}' is longer than 31 characters which is not allowed!"); x;
description = ''
The name of the user account. If undefined, the name of the
@ -63,7 +69,7 @@ let
};
description = mkOption {
type = types.str;
type = passwdEntry types.str;
default = "";
example = "Alice Q. User";
description = ''
@ -128,7 +134,7 @@ let
};
home = mkOption {
type = types.path;
type = passwdEntry types.path;
default = "/var/empty";
description = "The user's home directory.";
};
@ -157,7 +163,7 @@ let
};
shell = mkOption {
type = types.nullOr (types.either types.shellPackage types.path);
type = types.nullOr (types.either types.shellPackage (passwdEntry types.path));
default = pkgs.shadow;
defaultText = "pkgs.shadow";
example = literalExample "pkgs.bashInteractive";
@ -217,7 +223,7 @@ let
};
hashedPassword = mkOption {
type = with types; nullOr str;
type = with types; nullOr (passwdEntry str);
default = null;
description = ''
Specifies the hashed password for the user.
@ -251,7 +257,7 @@ let
};
initialHashedPassword = mkOption {
type = with types; nullOr str;
type = with types; nullOr (passwdEntry str);
default = null;
description = ''
Specifies the initial hashed password for the user, i.e. the
@ -323,7 +329,7 @@ let
options = {
name = mkOption {
type = types.str;
type = passwdEntry types.str;
description = ''
The name of the group. If undefined, the name of the attribute set
will be used.
@ -340,7 +346,7 @@ let
};
members = mkOption {
type = with types; listOf str;
type = with types; listOf (passwdEntry str);
default = [];
description = ''
The user names of the group members, added to the