From 9a8f705eddd18ccc9a24fe0e7efe6b5a87b2be09 Mon Sep 17 00:00:00 2001
From: Guilhem Moulin <guilhem@fripost.org>
Date: Thu, 25 Feb 2021 01:41:59 +0100
Subject: lacme: pass a temporary JSON file with the client configuration to
 the internal client.

So it doesn't have to parse the INI file again.  Also, while lacme.conf
is world-readable by default, one might restrict permissions and add
private information in there, not realizing that everything, including
comments, will be readable by the client.
---
 Changelog             |  2 ++
 client                |  8 +-------
 lacme                 | 26 ++++++++++++++++----------
 tests/drop-privileges |  4 ++--
 4 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/Changelog b/Changelog
index d63c754..8bf0721 100644
--- a/Changelog
+++ b/Changelog
@@ -11,6 +11,8 @@ lacme (0.8.1) upstream;
    'chmod'.
  + lacme: split certificates using Net::SSLeay::PEM_* instead of calling
    openssl.
+ + lacme: pass a temporary JSON file with the client configuration to
+   the internal client, so it doesn't have to parse the INI file again.
  - lacme: in the [accountd] config, let lacme-accountd(1) do the
    %-expansion for 'config', not lacme(8) when building the command.
  - lacme-accountd: don't log debug messages unless --debug is set.
diff --git a/client b/client
index 33189d3..8439ddb 100755
--- a/client
+++ b/client
@@ -56,8 +56,6 @@ use Date::Parse ();
 use LWP::UserAgent ();
 use JSON ();
 
-use Config::Tiny ();
-
 # Clean up PATH
 $ENV{PATH} = join ':', qw{/usr/bin /bin};
 delete @ENV{qw/IFS CDPATH ENV BASH_ENV/};
@@ -107,11 +105,7 @@ do {
 
 my $CONFIG = do {
     my $conf = do { local $/ = undef; <$CONFFILE> };
-    close $CONFFILE or die "close: $!";
-    my $h = Config::Tiny::->read_string($conf) or die Config::Tiny::->errstr()."\n";
-    $h->{_} //= {};
-    $h->{client}->{$_} //= $h->{_}->{$_} foreach keys %{$h->{_}}; # add defaults
-    $h->{client};
+    JSON::->new->decode($conf);
 };
 my $UA = do {
     my %args = %$CONFIG;
diff --git a/lacme b/lacme
index 13c2ef5..d7dac54 100755
--- a/lacme
+++ b/lacme
@@ -37,13 +37,14 @@ use Socket 1.95 qw/AF_UNIX AF_INET AF_INET6 PF_UNIX PF_INET PF_INET6 PF_UNSPEC
 
 use Config::Tiny ();
 use Date::Parse ();
+use JSON ();
 use Net::SSLeay 1.46 ();
 
 # Clean up PATH
 $ENV{PATH} = join ':', qw{/usr/bin /bin};
 delete @ENV{qw/IFS CDPATH ENV BASH_ENV/};
 
-my ($COMMAND, %OPTS, $CONFFILE, $CONFIG, @CLEANUP);
+my ($COMMAND, %OPTS, $CONFIG, @CLEANUP);
 $SIG{$_} = sub() { exit 1 } foreach qw/INT TERM/; # run the END block upon SIGINT/SIGTERM
 
 
@@ -99,14 +100,12 @@ sub spec_expand($) {
     return $str;
 }
 
-sub set_FD_CLOEXEC($$);
 my $CONFFILENAME = spec_expand($OPTS{config} // "%E/lacme/$NAME.conf");
 do {
     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> };
-    # don't close $CONFFILE so we can pass it to the client
-    set_FD_CLOEXEC($CONFFILE, 1);
+    open my $fh, '<', $CONFFILENAME or die "Can't open $CONFFILENAME: $!\n";
+    my $conf = do { local $/ = undef; <$fh> };
+    close $fh or die "close: $!";
 
     my $h = Config::Tiny::->read_string($conf) or die Config::Tiny::->errstr()."\n";
     my $defaults = delete $h->{_} // {};
@@ -573,19 +572,26 @@ sub acme_client($@) {
             die "connect: $!";
         }
     }
+    set_FD_CLOEXEC($client, 1);
+
+    my $client_config;
+    do {
+        my $tmp = File::Temp::->new(TMPDIR => 1, TEMPLATE => "lacme-client.conf.json-XXXXXXXXXX", UNLINK => 1) // die;
+        print $tmp JSON::->new->encode($conf);
+        open $client_config, "<", $tmp->filename() or die "open: $!";
+    };
 
     # use execve(2) rather than a Perl pseudo-process to ensure that the
     # child doesn't have access to the parent's memory
     my ($cmd, @args2) = split(/\s+/, $conf->{command}) or die "Empty client command\n";
-    my @fileno = map { fileno($_) =~ /^(\d+)$/ ? $1 : die } ($CONFFILE, $client); # untaint fileno
-    set_FD_CLOEXEC($client, 1);
+    my @fileno = map { fileno($_) =~ /^(\d+)$/ ? $1 : die } ($client_config, $client); # untaint fileno
     my $rv = spawn({in => $args->{in}, out => $args->{out}, child => sub() {
         drop_privileges($conf->{user}, $conf->{group}, $args->{chdir} // '/');
         umask(0022) // die;
-        set_FD_CLOEXEC($_, 0) foreach ($CONFFILE, $client);
-        seek($CONFFILE, SEEK_SET, 0) or die "seek: $!";
+        set_FD_CLOEXEC($_, 0) for ($client_config, $client);
         $ENV{DEBUG} = $OPTS{debug} // 0;
     }}, $cmd, @args2, $COMMAND, @fileno, @args);
+    close $client_config or die "close: $!\n";
 
     if (defined $cleanup) {
         @CLEANUP = grep { $_ ne $cleanup } @CLEANUP;
diff --git a/tests/drop-privileges b/tests/drop-privileges
index fd432d9..8deb8f1 100644
--- a/tests/drop-privileges
+++ b/tests/drop-privileges
@@ -123,8 +123,8 @@ check_client() {
     grep -Exq "[0-9]+ 0700 $UID:$GID socket:\[[0-9]+\]" "$prefix/fd" || return 1
     sed -ri '0,\#^[0-9]+ .* socket:\[[0-9]+\]$# {//d}' "$prefix/fd"
 
-    grep -Exq "[0-9]+ 0500 $UID:$GID /etc/lacme/lacme\.conf" "$prefix/fd" || return 1
-    sed -ri '0,\#^[0-9]+ .* /etc/lacme/lacme\.conf$# {//d}' "$prefix/fd"
+    grep -Eq "^[0-9]+ 0500 $UID:$GID /tmp/lacme-client.conf\.json-" "$prefix/fd" || return 1
+    sed -ri '0,\#^[0-9]+ .* /tmp/lacme-client.conf\.json-# {//d}' "$prefix/fd"
     ! test -s "$prefix/fd" || return 1
 }
 check_webserver() {
-- 
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