From 9a2a5edacc95c630d37d1215b0c7c938f82b998d Mon Sep 17 00:00:00 2001 From: Guilhem Moulin Date: Tue, 15 Sep 2015 02:10:55 +0200 Subject: [PATCH] Add the ability to proxy TCP connections through a SOCKSv5 proxy. --- Changelog | 2 + interimap.1 | 10 +++ interimap.sample | 1 + lib/Net/IMAP/InterIMAP.pm | 143 ++++++++++++++++++++++++++++++++++---- 4 files changed, 142 insertions(+), 14 deletions(-) diff --git a/Changelog b/Changelog index 8e5fad7..978f8e5 100644 --- a/Changelog +++ b/Changelog @@ -25,6 +25,8 @@ interimap (0.2) upstream; * Accept non-fully qualified commands. * Replace IO::Socket::INET dependency by the lower lever Socket to enable IPv6. (Both are core Perl module.) + * Add a configuration option 'proxy' to proxy TCP connections to the + IMAP server. -- Guilhem Moulin Wed, 09 Sep 2015 00:44:35 +0200 diff --git a/interimap.1 b/interimap.1 index ef0752e..4822259 100644 --- a/interimap.1 +++ b/interimap.1 @@ -254,6 +254,16 @@ Server port. (Default: \(lq143\(rq for \fItype\fR=imap, \(lq993\(rq for \fItype\fR=imaps.) +.TP +.I proxy +An optional SOCKS proxy to use for TCP connections to the IMAP server +(\fItype\fR=imap and \fItype\fR=imaps only), formatted as +\(lq\fIprotocol\fR://[\fIuser\fR:\fIpassword\fR@]\fIproxyhost\fR[:\fIproxyport\fR]\(rq. +If \fIproxyport\fR is omitted, it is assumed at port 1080. +Only SOCKSv5 is supported, in two flavors: \(lqsocks5://\(rq to resolve +\fIhostname\fR locally, and \(lqsocks5h://\(rq to let the proxy resolve +\fIhostname\fR. + .TP .I command Command to use for \fItype\fR=tunnel. Must speak the IMAP4rev1 protocol diff --git a/interimap.sample b/interimap.sample index bbf8c42..a6dc450 100644 --- a/interimap.sample +++ b/interimap.sample @@ -13,6 +13,7 @@ null-stderr = YES # type = imaps host = imap.guilhem.org # port = 993 +#proxy = socks5h://localhost:9050 username = guilhem password = xxxxxxxxxxxxxxxx #compress = YES diff --git a/lib/Net/IMAP/InterIMAP.pm b/lib/Net/IMAP/InterIMAP.pm index 0762b3b..6f44879 100644 --- a/lib/Net/IMAP/InterIMAP.pm +++ b/lib/Net/IMAP/InterIMAP.pm @@ -26,7 +26,7 @@ use IO::Select (); use Net::SSLeay (); use List::Util 'first'; use POSIX ':signal_h'; -use Socket qw/SOL_SOCKET SO_KEEPALIVE SOCK_STREAM IPPROTO_TCP/; +use Socket qw/SOL_SOCKET SO_KEEPALIVE SOCK_STREAM IPPROTO_TCP AF_INET AF_INET6 SOCK_RAW :addrinfo/; use Exporter 'import'; BEGIN { @@ -47,6 +47,7 @@ my $RE_TEXT_CHAR = qr/[\x01-\x09\x0B\x0C\x0E-\x7F]/; my %OPTIONS = ( host => qr/\A(\P{Control}+)\z/, port => qr/\A(\P{Control}+)\z/, + proxy => qr/\A(\P{Control}+)\z/, type => qr/\A(imaps?|tunnel)\z/, STARTTLS => qr/\A(YES|NO)\z/i, username => qr/\A([\x01-\x7F]+)\z/, @@ -286,7 +287,8 @@ sub new($%) { foreach (qw/host port/) { $self->fail("Missing option $_") unless defined $self->{$_}; } - my $socket = $self->_tcp_connect(@$self{qw/host port/}); + my $socket = defined $self->{proxy} ? $self->_proxify(@$self{qw/proxy host port/}) + : $self->_tcp_connect(@$self{qw/host port/}); setsockopt($socket, SOL_SOCKET, SO_KEEPALIVE, 1) or $self->fail("Can't setsockopt SO_KEEPALIVE: $!"); $self->_start_ssl($socket) if $self->{type} eq 'imaps'; @@ -494,19 +496,21 @@ sub logger($@) { } -# $self->warn($warning, [...]) +# $self->warn([$type,] $warning) # Log a $warning. -sub warn($$@) { - my $self = shift; - $self->log('WARNING: ', @_); +sub warn($$;$) { + my ($self, $msg, $t) = @_; + $msg = defined $t ? "$msg WARNING: $t" : "WARNING: $msg"; + $self->log($msg); } -# $self->fail($error, [...]) +# $self->fail([$type,] $error) # Log an $error and exit with return value 1. -sub fail($$@) { - my $self = shift; - $self->log('ERROR: ', @_); +sub fail($$;$) { + my ($self, $msg, $t) = @_; + $msg = defined $t ? "$msg ERROR: $t" : "ERROR: $msg"; + $self->log($msg); exit 1; } @@ -926,8 +930,8 @@ sub set_cache($$%) { while (my ($k, $v) = each %status) { if ($k eq 'UIDVALIDITY') { # try to detect UIDVALIDITY changes early (before starting the sync) - $self->fail("UIDVALIDITY changed! ($cache->{UIDVALIDITY} != $v) ", - "Need to invalidate the UID cache.") + $self->fail("UIDVALIDITY changed! ($cache->{UIDVALIDITY} != $v) ". + "Need to invalidate the UID cache.") if defined $cache->{UIDVALIDITY} and $cache->{UIDVALIDITY} != $v; } $cache->{$k} = $v; @@ -1245,7 +1249,7 @@ sub _tcp_connect($$$) { $hints{flags} |= AI_NUMERICHOST; } - my ($err, @res) = Socket::getaddrinfo($host, $port, \%hints); + my ($err, @res) = getaddrinfo($host, $port, \%hints); $self->fail("Can't getaddrinfo: $err") if $err ne ''; foreach my $ai (@res) { @@ -1255,6 +1259,117 @@ sub _tcp_connect($$$) { $self->fail("Can't connect to $host:$port"); } +sub _xwrite($$$) { + my $self = shift; + my ($offset, $length) = (0, length $_[1]); + + while ($length > 0) { + my $n = syswrite($_[0], $_[1], $length, $offset); + $self->fail("Can't write: $!") unless defined $n and $n > 0; + $offset += $n; + $length -= $n; + } +} + + +sub _xread($$$) { + my ($self, $fh, $length) = @_; + my $offset = 0; + my $buf; + while ($length > 0) { + my $n = sysread($fh, $buf, $length, $offset) // $self->fail("Can't read: $!"); + $self->fail("0 bytes read (got EOF)") unless $n > 0; # EOF + $offset += $n; + $length -= $n; + } + return $buf; +} + + +# $self->_proxify($proxy, $host, $port) +# Initiate the given $proxy to proxy TCP connections to $host:$port. +sub _proxify($$$$) { + my ($self, $proxy, $host, $port) = @_; + $port = getservbyname($port, 'tcp') // $self->fail("Can't getservbyname $port") + unless $port =~ /\A[0-9]+\z/; + + $proxy =~ /\A([A-Za-z0-9]+):\/\/(\P{Control}*\@)?($RE_IPv4|\[$RE_IPv6\]|[^:]+)(:[A-Za-z0-9]+)?\z/ + or $self->fail("Invalid proxy URI $proxy"); + my ($proto, $userpass, $proxyhost, $proxyport) = ($1, $2, $3, $4); + $userpass =~ s/\@\z// if defined $userpass; + $proxyport = defined $proxyport ? $proxyport =~ s/\A://r : 1080; + + my $socket = $self->_tcp_connect($proxyhost, $proxyport); + if ($proto eq 'socks5' or $proto eq 'socks5h') { + my $resolv = $proto eq 'socks5h' ? 1 : 0; + my $v = 0x05; # RFC 1928 VER protocol version + + my %mech = ( ANON => 0x00 ); + $mech{USERPASS} = 0x02 if defined $userpass; + + $self->_xwrite($socket, pack('CCC*', 0x05, scalar (keys %mech), values %mech)); + my ($v2, $m) = unpack('CC', $self->_xread($socket, 2)); + $self->fail('SOCKSv5', 'Invalid protocol') unless $v == $v2; + + %mech = reverse %mech; + my $mech = $mech{$m} // ''; + if ($mech eq 'USERPASS') { # RFC 1929 Username/Password Authentication for SOCKS V5 + my $v = 0x01; # current version of the subnegotiation + my ($u, $pw) = split /:/, $userpass, 2; + + $self->_xwrite($socket, pack('C2', $v,length($u)).$u.pack('C',length($pw)).$pw); + my ($v2, $r) = unpack('C2', $self->_xread($socket, 2)); + $self->fail('SOCKSv5', 'Invalid protocol') unless $v == $v2; + $self->fail('SOCKSv5', 'Authentication failed') unless $r == 0x00; + } + elsif ($mech ne 'ANON') { # $m == 0xFF + $self->fail('SOCKSv5', 'No acceptable authentication methods'); + } + + if ($host !~ /\A(?:$RE_IPv4|\[$RE_IPv6\])\z/ and !$resolv) { + # resove the hostname $host locally + my ($err, @res) = getaddrinfo($host, undef, {socktype => SOCK_RAW}); + $self->fail("Can't getaddrinfo: $err") if $err ne ''; + ($host) = first { defined $_ } map { + my ($err, $ipaddr) = getnameinfo($_->{addr}, NI_NUMERICHOST, NIx_NOSERV); + $err eq '' ? $ipaddr : undef + } @res; + $self->fail("Can't getnameinfo") unless defined $host; + } + + # send a CONNECT command (CMD 0x01) + my ($typ, $addr) = + $host =~ /\A$RE_IPv4\z/ ? (0x01, Socket::inet_pton(AF_INET, $host)) + : ($host =~ /\A\[($RE_IPv6)\]\z/ or $host =~ /\A($RE_IPv6)\z/) ? (0x04, Socket::inet_pton(AF_INET6, $1)) + : (0x03, pack('C',length($host)).$host); + $self->_xwrite($socket, pack('C4', $v, 0x01, 0x00, $typ).$addr.pack('n', $port)); + + ($v2, my $r, my $rsv, $typ) = unpack('C4', $self->_xread($socket, 4)); + $self->fail('SOCKSv5', 'Invalid protocol') unless $v == $v2 and $rsv == 0x00; + my $err = $r == 0x00 ? undef + : $r == 0x01 ? 'general SOCKS server failure' + : $r == 0x02 ? 'connection not allowed by ruleset' + : $r == 0x03 ? 'network unreachable' + : $r == 0x04 ? 'host unreachable' + : $r == 0x05 ? 'connection refused' + : $r == 0x06 ? 'TTL expired' + : $r == 0x07 ? 'command not supported' + : $r == 0x08 ? 'address type not supported' + : $self->panic(); + $self->fail('SOCKSv5', $err) if defined $err; + + my $len = $typ == 0x01 ? 4 + : $typ == 0x03 ? unpack('C', $self->_xread($socket, 1)) + : $typ == 0x04 ? 16 + : $self->panic(); + $self->_xread($socket, $len + 2); # consume (and ignore) the rest of the response + return $socket; + } + else { + $self->error("Unsupported proxy protocol $proto"); + } +} + # $self->_start_ssl($socket) # Upgrade the $socket to SSL/TLS. @@ -1409,7 +1524,7 @@ sub _update_cache_for($$%) { while (my ($k, $v) = each %status) { if ($k eq 'UIDVALIDITY') { # try to detect UIDVALIDITY changes early (before starting the sync) - $self->fail("UIDVALIDITY changed! ($cache->{UIDVALIDITY} != $v) ", + $self->fail("UIDVALIDITY changed! ($cache->{UIDVALIDITY} != $v) ". "Need to invalidate the UID cache.") if defined $cache->{UIDVALIDITY} and $cache->{UIDVALIDITY} != $v; $self->{_PCACHE}->{$mailbox}->{UIDVALIDITY} //= $v; -- 2.39.2