From 0ef94d85e58497dcb2c4c954cadcac918032467a Mon Sep 17 00:00:00 2001
From: Guilhem Moulin <guilhem@fripost.org>
Date: Thu, 18 Feb 2021 21:07:01 +0100
Subject: Add %-specifiers support.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

lacme(8): for --config=, --socket=, --config-certs= (and ‘socket’/
‘config-certs’/‘challenge-directory’ configuration options *before*
privilege drop; and for the [accountd] section ‘command’/‘config’
configuration options *after* privilege drop).

lacme-accountd(1): for --config=, --socket= and --privkey= (and
‘socket’/‘privkey’ configuration options).

This also changes the default configuration file location.  lacme(8) and
lacme-accountd(1) now respectively use /etc/lacme/lacme.conf resp.
/etc/lacme/lacme-accountd.conf when running as root, and
$XDG_CONFIG_HOME/lacme/lacme.conf resp. $XDG_CONFIG_HOME/lacme/lacme-accountd.conf
when running as a normal user.  There is no fallback to /etc anymore.
---
 lacme | 39 +++++++++++++++++++++++++++++++--------
 1 file changed, 31 insertions(+), 8 deletions(-)

(limited to 'lacme')

diff --git a/lacme b/lacme
index 9a62cbb..ad7e1d8 100755
--- a/lacme
+++ b/lacme
@@ -75,13 +75,33 @@ $COMMAND = $COMMAND =~ /\A(account|newOrder|new-cert|revokeCert|revoke-cert)\z/
          : usage(1, "Invalid command: $COMMAND"); # validate and untaint $COMMAND
 @ARGV = map { /\A(\p{Print}*)\z/ ? $1 : die } @ARGV; # untaint @ARGV
 
+sub env_fallback($$) {
+    my $v = $ENV{ shift() };
+    return (defined $v and $v ne "") ? $v : shift;
+}
+sub spec_expand($) {
+    my $str = shift;
+    $str =~ s#%(.)# my $x =
+          $1 eq "C" ? ($< == 0 ? "@@localstatedir@@/cache" : env_fallback(XDG_CACHE_HOME => "$ENV{HOME}/.cache"))
+        : $1 eq "E" ? ($< == 0 ? "@@sysconfdir@@" : env_fallback(XDG_CONFIG_HOME => "$ENV{HOME}/.config"))
+        : $1 eq "g" ? (getgrgid((split /\s/,$()[0]))[0]
+        : $1 eq "G" ? $( =~ s/\s.*//r
+        : $1 eq "h" ? (getpwuid($<))[7]
+        : $1 eq "u" ? (getpwuid($<))[0]
+        : $1 eq "U" ? $<
+        : $1 eq "t" ? ($< == 0 ? "@@runstatedir@@" : $ENV{XDG_RUNTIME_DIR})
+        : $1 eq "T" ? env_fallback(TMPDIR => "/tmp")
+        : $1 eq "%" ? "%"
+        : die "Error: \"$str\" has unknown specifier %$1\n";
+        die "Error: undefined expansion %$1 in \"$str\"\n" unless defined $x;
+        $x;
+    #ge;
+    return $str;
+}
+
 sub set_FD_CLOEXEC($$);
-my $CONFFILENAME = $OPTS{config} // first { -f $_ }
-   ( ($ENV{XDG_CONFIG_HOME} // "$ENV{HOME}/.config") . "/lacme/$NAME.conf"
-   , "@@sysconfdir@@/lacme/$NAME.conf"
-   );
+my $CONFFILENAME = spec_expand($OPTS{config} // "%E/lacme/$NAME.conf");
 do {
-    die "Error: Can't find configuration file\n" unless defined $CONFFILENAME;
     print STDERR "Using configuration file: $CONFFILENAME\n" if $OPTS{debug};
     open $CONFFILE, '<', $CONFFILENAME or die "Can't open $CONFFILENAME: $!\n";
     my $conf = do { local $/ = undef; <$CONFFILE> };
@@ -93,7 +113,7 @@ do {
     my $accountd = defined $OPTS{socket} ? 0 : exists $h->{accountd} ? 1 : 0;
     my %valid = (
         client => {
-            socket  => (defined $ENV{XDG_RUNTIME_DIR} ? "$ENV{XDG_RUNTIME_DIR}/S.lacme" : undef),
+            socket  => '%t/S.lacme',
             user    => '@@lacme_client_user@@',
             group   => '@@lacme_client_group@@',
             command => '@@libexecdir@@/lacme/client',
@@ -285,6 +305,7 @@ sub spawn_webserver() {
     # Use existing HTTPd to serve challenge files using 'challenge-directory'
     # as document root
     if (defined (my $dir = $conf->{'challenge-directory'})) {
+        $dir = spec_expand($dir);
         print STDERR "[$$] Using existing webserver on $dir\n" if $OPTS{debug};
         # lacme(8) doesn't have the list of challenge files to delete on
         # cleanup -- instead, we unlink all files and fails at
@@ -513,8 +534,9 @@ sub acme_client($@) {
             set_FD_CLOEXEC($s, 1);
             $ENV{GPG_TTY} = $GPG_TTY if defined $GPG_TTY;
             my ($cmd, @args) = split(/\s+/, $accountd->{command}) or die "Empty accountd command\n";
+            $_ = spec_expand($_) foreach ($cmd, @args); # expand %-specifiers after privilege drop and whitespace split
             push @args, '--stdio';
-            push @args, '--config='.$accountd->{config}   if $accountd->{config} ne '';
+            push @args, '--config='.spec_expand($accountd->{config}) if $accountd->{config} ne '';
             push @args, '--privkey='.$accountd->{privkey} if $accountd->{privkey} ne ''; # XXX deprecated in 0.8.0
             push @args, '--quiet' unless lc $accountd->{quiet} eq 'no';
             push @args, '--debug' if $OPTS{debug};
@@ -531,7 +553,7 @@ sub acme_client($@) {
     }
     else {
         my @stat;
-        my $sockname = $OPTS{socket} // $conf->{socket} // die "Missing socket option\n";
+        my $sockname = spec_expand($OPTS{socket} // $conf->{socket});
         $sockname = $sockname =~ /\A(\p{Print}+)\z/ ? $1 : die "Invalid socket name\n"; # untaint $sockname
 
         # ensure we're the only user with write access to the parent dir
@@ -697,6 +719,7 @@ elsif ($COMMAND eq 'newOrder' or $COMMAND eq 'new-cert') {
     my $conffiles = defined $OPTS{'config-certs'} ? $OPTS{'config-certs'}
                   : defined $CONFIG->{_}->{'config-certs'} ? [ split(/\s+/, $CONFIG->{_}->{'config-certs'}) ]
                   : [ "$NAME-certs.conf", "$NAME-certs.conf.d/" ];
+    $_ = spec_expand($_) foreach @$conffiles;
     my ($conf, %defaults);
     foreach my $conffile (@$conffiles) {
         $conffile = dirname($CONFFILENAME) .'/'. $conffile unless $conffile =~ /\A\//;
-- 
cgit v1.2.3