lei: IMAP .onion support via --proxy=s switch

Mail::IMAPClient provides the ability to pass a pre-connected
Socket to it.  We can rely on this functionality to use
IO::Socket::Socks in place whatever socket class
Mail::IMAPClient chooses to use.

The --proxy=s is shared with curl(1), though we only support
socks5h:// at the moment.  Is there any need for SOCKS4 or SOCKS5
without name resolution?  Tor .onions require socks5h:// for
name resolution and to prevent data leakage.

1 files changed, 28 insertions, 3 deletions

diff --git a/lib/PublicInbox/NetReader.pm b/lib/PublicInbox/NetReader.pm
index b9365c05..ac23e701 100644
--- a/lib/PublicInbox/NetReader.pm
+++ b/lib/PublicInbox/NetReader.pm
@@ -7,6 +7,7 @@ use strict;
 use v5.10.1;
 use parent qw(Exporter PublicInbox::IPC);
 use PublicInbox::Eml;
+use PublicInbox::Config;
 our %IMAPflags2kw = map {; "\\\u$_" => $_ } qw(seen answered flagged draft);
 $IMAPflags2kw{'$Forwarded'} = 'forwarded';  # RFC 5550
 
@@ -51,7 +52,16 @@ sub mic_for ($$$$) { # mic = Mail::IMAPClient
                 %$common, # may set Starttls, Compress, Debug ....
         };
         require PublicInbox::IMAPClient;
-        my $mic = PublicInbox::IMAPClient->new(%$mic_arg) or
+        my %socks;
+        if ($lei && $lei->{socks5h}) {
+                my %opt = %{$lei->{socks5h}};
+                $opt{ConnectAddr} = delete $mic_arg->{Server};
+                $opt{ConnectPort} = delete $mic_arg->{Port};
+                $socks{Socket} = IO::Socket::Socks->new(%opt) or die
+                        "E: <$url> ".eval('$IO::Socket::Socks::SOCKS_ERROR');
+                $self->{mic_socks5h} = \%opt;
+        }
+        my $mic = PublicInbox::IMAPClient->new(%$mic_arg, %socks) or
                 die "E: <$url> new: $@\n";
 
         # default to using STARTTLS if it's available, but allow
@@ -331,7 +341,7 @@ sub add_url {
 }
 
 sub errors {
-        my ($self) = @_;
+        my ($self, $lei) = @_;
         if (my $u = $self->{unsupported_url}) {
                 return "Unsupported URL(s): @$u";
         }
@@ -343,6 +353,16 @@ sub errors {
                 eval { require Net::NNTP } or
                         die "Net::NNTP is required for NNTP:\n$@\n";
         }
+        if ($lei && (($lei->{opt}->{proxy}//'') =~ m!\Asocks5h://
+                                (?: \[ ([^\]]+) \] | ([^:/]+) )
+                                (?::([0-9]+))?/?(?:,|\z)!ix)) {
+                my ($h, $p) = ($1 // $2, $3 + 0);
+                $h = '127.0.0.1' if $h eq '0';
+                eval { require IO::Socket::Socks } or die <<EOM;
+IO::Socket::Socks missing for socks5h://$h:$p
+EOM
+                $lei->{socks5h} = { ProxyAddr => $h, ProxyPort => $p };
+        }
         undef;
 }
 
@@ -507,7 +527,12 @@ sub mic_get {
                         $mic_arg->{Authcallback} = $self->can($cb_name);
                 }
         }
-        my $mic = PublicInbox::IMAPClient->new(%$mic_arg);
+        my %socks;
+        if (my $s5h = $self->{mic_socks5h}) {
+                $socks{Socket} = IO::Socket::Socks->new(%$s5h) or die
+                        "E: <$$uri> ".eval('$IO::Socket::Socks::SOCKS_ERROR');
+        }
+        my $mic = PublicInbox::IMAPClient->new(%$mic_arg, %socks);
         $cached //= {}; # invalid placeholder if no cache enabled
         $mic && $mic->IsConnected ? ($cached->{$sec} = $mic) : undef;
 }