gpg: support declarative trust and public keys

PR #810
This commit is contained in:
Miles Breslin 2019-08-20 01:30:13 -07:00 committed by Robert Helgesson
parent 579f2e8beb
commit ea1794a798
No known key found for this signature in database
GPG key ID: 36BDAA14C2797E89
5 changed files with 278 additions and 1 deletions

View file

@ -21,6 +21,110 @@ let
} cfg.scdaemonSettings;
primitiveType = types.oneOf [ types.str types.bool ];
publicKeyOpts = { config, ...}: {
options = {
text = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
Text of an OpenPGP public key.
'';
};
source = mkOption {
type = types.path;
description = ''
Path of an OpenPGP public key file.
'';
};
trust = mkOption {
type = types.nullOr (types.enum [ 1 2 3 4 5 ]);
default = null;
description = ''
The amount of trust you have in the key ownership and the care the
owner puts into signing other keys. The available levels are
<variablelist>
<varlistentry>
<term><literal>1</literal></term>
<listitem><para>I don't know or won't say.</para></listitem>
</varlistentry>
<varlistentry>
<term><literal>2</literal></term>
<listitem><para>I do NOT trust.</para></listitem>
</varlistentry>
<varlistentry>
<term><literal>3</literal></term>
<listitem><para>I trust marginally.</para></listitem>
</varlistentry>
<varlistentry>
<term><literal>4</literal></term>
<listitem><para>I trust fully.</para></listitem>
</varlistentry>
<varlistentry>
<term><literal>5</literal></term>
<listitem><para>I trust ultimately.</para></listitem>
</varlistentry>
</variablelist>
</para><para>
See <link xlink:href="https://www.gnupg.org/gph/en/manual/x334.html"/>
for more.
'';
};
};
config = {
source = mkIf (config.text != null)
(pkgs.writeText "gpg-pubkey" config.text);
};
};
importTrustBashFunctions =
let gpg = "${cfg.package}/bin/gpg";
in ''
function gpgKeyId() {
${gpg} --show-key --with-colons "$1" \
| grep ^pub: \
| cut -d: -f5
}
function importTrust() {
local keyId trust
keyId="$(gpgKeyId "$1")"
trust="$2"
if [[ -n $keyId ]] ; then
echo -e "trust\n$trust\ny\nquit" \
| ${gpg} --no-tty --command-fd 0 --edit-key "$keyId"
fi
}
'';
keyringFiles =
let
gpg = "${cfg.package}/bin/gpg";
importKey = { source, trust, ... }: ''
${gpg} --import ${source}
${optionalString (trust != null) ''
importTrust "${source}" ${toString trust}''}
'';
importKeys = concatMapStringsSep "\n" importKey cfg.publicKeys;
in pkgs.runCommand "gpg-pubring" { buildInputs = [ cfg.package ]; } ''
export GNUPGHOME
GNUPGHOME=$(mktemp -d)
${importTrustBashFunctions}
${importKeys}
mkdir $out
cp $GNUPGHOME/pubring.kbx $out/pubring.kbx
if [[ -e $GNUPGHOME/trustdb.gpg ]] ; then
cp $GNUPGHOME/trustdb.gpg $out/trustdb.gpg
fi
'';
in
{
options.programs.gpg = {
@ -73,6 +177,48 @@ in
defaultText = literalExpression "\"\${config.home.homeDirectory}/.gnupg\"";
description = "Directory to store keychains and configuration.";
};
mutableKeys = mkOption {
type = types.bool;
default = true;
description = ''
If set to <literal>true</literal>, you may manage your keyring as a user
using the <literal>gpg</literal> command. Upon activation, the keyring
will have managed keys added without overwriting unmanaged keys.
</para><para>
If set to <literal>false</literal>, the path
<filename>$GNUPGHOME/pubring.kbx</filename> will become an immutable
link to the Nix store, denying modifications.
'';
};
mutableTrust = mkOption {
type = types.bool;
default = true;
description = ''
If set to <literal>true</literal>, you may manage trust as a user using
the <command>gpg</command> command. Upon activation, trusted keys have
their trust set without overwriting unmanaged keys.
</para><para>
If set to <literal>false</literal>, the path
<filename>$GNUPGHOME/trustdb.gpg</filename> will be
<emphasis>overwritten</emphasis> on each activation, removing trust for
any unmanaged keys. Be careful to make a backup of your old
<filename>trustdb.gpg</filename> before switching to immutable trust!
'';
};
publicKeys = mkOption {
type = types.listOf (types.submodule publicKeyOpts);
example = literalExpression ''
[ { source = ./pubkeys.txt; } ]
'';
default = [ ];
description = ''
A list of public keys to be imported into GnuPG. Note, these key files
will be copied into the world-readable Nix store.
'';
};
};
config = mkIf cfg.enable {
@ -109,5 +255,48 @@ in
home.file."${cfg.homedir}/gpg.conf".text = cfgText;
home.file."${cfg.homedir}/scdaemon.conf".text = scdaemonCfgText;
# Link keyring if keys are not mutable
home.file."${cfg.homedir}/pubring.kbx" =
mkIf (!cfg.mutableKeys && cfg.publicKeys != []) {
source = "${keyringFiles}/pubring.kbx";
};
home.activation = mkIf (cfg.publicKeys != []) {
importGpgKeys =
let
gpg = "${cfg.package}/bin/gpg";
importKey = { source, trust, ... }:
# Import mutable keys
optional cfg.mutableKeys ''
$DRY_RUN_CMD ${gpg} $QUIET_ARG --import ${source}''
# Import mutable trust
++ optional (trust != null && cfg.mutableTrust) ''
$DRY_RUN_CMD importTrust "${source}" ${toString trust}'';
anyTrust = any (k: k.trust != null) cfg.publicKeys;
importKeys = concatStringsSep "\n" (concatMap importKey cfg.publicKeys);
# If any key/trust should be imported then create the block. Otherwise
# leave it empty.
block = concatStringsSep "\n" (
optional (importKeys != "") ''
export GNUPGHOME=${escapeShellArg cfg.homedir}
if [[ ! -v VERBOSE ]]; then
QUIET_ARG="--quiet"
else
QUIET_ARG=""
fi
${importTrustBashFunctions}
${importKeys}
unset GNUPGHOME QUIET_ARG keyId importTrust
'' ++ optional (!cfg.mutableTrust && anyTrust) ''
install -m 0700 ${keyringFiles}/trustdb.gpg "${cfg.homedir}/trustdb.gpg"''
);
in lib.hm.dag.entryAfter ["linkGeneration"] block;
};
};
}