--- AnyEvent-MP/MP/Transport.pm 2009/07/30 08:38:50 1.1 +++ AnyEvent-MP/MP/Transport.pm 2009/08/03 22:05:55 1.13 @@ -1,6 +1,6 @@ =head1 NAME -AnyEvent::MP::Transport - actual transport protocol +AnyEvent::MP::Transport - actual transport protocol handler =head1 SYNOPSIS @@ -8,10 +8,11 @@ =head1 DESCRIPTION -This is the superclass for MP transports, most of which is considered an -implementation detail. +This implements the actual transport protocol for MP (it represents a +single link), most of which is considered an implementation detail. -Future versions might document the actual protocol. +See the "PROTOCOL" section below if you want to write another client for +this protocol. =head1 FUNCTIONS/METHODS @@ -26,17 +27,16 @@ use Scalar::Util; use MIME::Base64 (); use Storable (); +use JSON::XS (); use AE (); use AnyEvent::Socket (); use AnyEvent::Handle (); -use AnyEvent::MP (); use base Exporter::; our $VERSION = '0.0'; -our $PROTOCOL_VERSION_MAJOR = 0; -our $PROTOCOL_VERSION_MINOR = 0; +our $PROTOCOL_VERSION = 0; =item $listener = mp_listener $host, $port, , $cb->($transport) @@ -45,7 +45,7 @@ See C, below, for constructor arguments. -Defaults for peerhost, peerport, fh and tls are provided. +Defaults for peerhost, peerport and fh are provided. =cut @@ -60,7 +60,29 @@ fh => $fh, peerhost => $host, peerport => $port, - tls => "accept", + @args, + ); + } +} + +=item $guard = mp_connect $host, $port, , $cb->($transport) + +=cut + +sub mp_connect { + my $cb = pop; + my ($host, $port, @args) = @_; + + AnyEvent::Socket::tcp_connect $host, $port, sub { + my ($fh, $nhost, $nport) = @_; + + return $cb->() unless $fh; + + $cb->(new AnyEvent::MP::Transport + fh => $fh, + peername => $host, + peerhost => $nhost, + peerport => $nport, @args, ); } @@ -70,28 +92,32 @@ # immediately starts negotiation my $transport = new AnyEvent::MP::Transport - # fh OR connect is mandatory - fh => $filehandle, - connect => [$host, $port], - # mandatory + fh => $filehandle, + local_id => $identifier, on_recv => sub { receive-callback }, on_error => sub { error-callback }, # optional - local_id => $identifier, secret => "shared secret", on_eof => sub { clean-close-callback }, on_connect => sub { successful-connect-callback }, + greeting => { key => value }, # tls support - tls => "accept|connect", tls_ctx => AnyEvent::TLS, peername => $peername, # for verification ; =cut +our @FRAMINGS = qw(json storable); # the framing types we accept and send, in order of preference +our @AUTH_SND = qw(hmac_md6_64_256); # auth types we send +our @AUTH_RCV = (@AUTH_SND, qw(cleartext)); # auth types we accept + +#AnyEvent::Handle::register_write_type mp_record => sub { +#}; + sub new { my ($class, %arg) = @_; @@ -102,94 +128,149 @@ { Scalar::Util::weaken (my $self = $self); - if (exists $arg{connect}) { - $arg{tls} ||= "connect"; - $arg{tls_ctx} ||= { sslv2 => 0, sslv3 => 0, tlsv1 => 1, verify => 1, verify_peername => "https" }; - } + $arg{tls_ctx_disabled} ||= { + sslv2 => 0, + sslv3 => 0, + tlsv1 => 1, + verify => 1, + cert_file => "secret.pem", + ca_file => "secret.pem", + verify_require_client_cert => 1, + }; + + $arg{secret} = AnyEvent::MP::Base::default_secret () + unless exists $arg{secret}; $self->{hdl} = new AnyEvent::Handle - (exists $arg{fh} ? (fh => delete $arg{fh}) : (connect => delete $arg{connect})), + fh => delete $arg{fh}, + autocork => 1, + no_delay => 1, on_error => sub { $self->error ($_[2]); }, peername => delete $arg{peername}, ; - my $secret = delete $arg{secret} ? delete $arg{secret} : AnyEvent::MP::default_secret; + my $secret = $arg{secret}; + my $greeting_kv = $self->{greeting} ||= {}; + $greeting_kv->{"tls"} = "1.0" + if $arg{tls_ctx}; + $greeting_kv->{provider} = "AE-$VERSION"; + $greeting_kv->{peeraddr} = AnyEvent::Socket::format_hostport $self->{peerhost}, $self->{peerport}; # send greeting - my $lgreeting = "aemp;$PROTOCOL_VERSION_MAJOR;$PROTOCOL_VERSION_MINOR;AnyEvent::MP;$VERSION;" - . (MIME::Base64::encode_base64 AnyEvent::MP::nonce 33, "") . ";" - . "hmac_md6_64_256;" # hardcoded atm. - . "storable;" # hardcoded atm. - . "$self->{local_id};" - . (exists $arg{tls} && $arg{tls_ctx} ? "tls1.0=$arg{tls};" : ""); + my $lgreeting1 = "aemp;$PROTOCOL_VERSION" + . ";$AnyEvent::MP::Base::UNIQ" + . ";$AnyEvent::MP::Base::NODE" + . ";" . (join ",", @AUTH_RCV) + . ";" . (join ",", @FRAMINGS) + . (join "", map ";$_=$greeting_kv->{$_}", keys %$greeting_kv); + + my $lgreeting2 = MIME::Base64::encode_base64 AnyEvent::MP::Base::nonce (33), ""; - $self->{hdl}->push_write ("$lgreeting\012"); + $self->{hdl}->push_write ("$lgreeting1\012$lgreeting2\012"); # expect greeting + $self->{hdl}->rbuf_max (4 * 1024); $self->{hdl}->push_read (line => sub { - my $rgreeting = $_[1]; + my $rgreeting1 = $_[1]; - my ($aemp, $major, $minor, $provider, $provider_version, $nonce2, $auth, $framing, $rid, @kv) = split /;/, $rgreeting; + my ($aemp, $version, $uniq, $rnode, $auths, $framings, @kv) = split /;/, $rgreeting1; if ($aemp ne "aemp") { return $self->error ("unparsable greeting"); - } elsif ($major != $PROTOCOL_VERSION_MAJOR) { - return $self->error ("major version mismatch ($PROTOCOL_VERSION_MAJOR vs. $major)"); - } elsif ($auth ne "hmac_md6_64_256") { - return $self->error ("unsupported auth method ($auth)"); - } elsif ($framing ne "storable") { - return $self->error ("unsupported auth method ($auth)"); + } elsif ($version != $PROTOCOL_VERSION) { + return $self->error ("version mismatch (we: $PROTOCOL_VERSION, they: $version)"); } - $self->{remote_id} = $rid; + my $s_auth; + for my $auth_ (split /,/, $auths) { + if (grep $auth_ eq $_, @AUTH_SND) { + $s_auth = $auth_; + last; + } + } - $self->{greeting} = { - provider => $provider, - provider_version => $provider_version, - }; + defined $s_auth + or return $self->error ("$auths: no common auth type supported"); - /^([^=]+)(?:=(.*))?/ and $self->{greeting}{$1} = $2 - for @kv; + die unless $s_auth eq "hmac_md6_64_256"; # hardcoded atm. - if (exists $self->{tls} and $self->{tls_ctx} and exists $self->{greeting}{"tls1.0"}) { - if ($self->{tls} ne $self->{greeting}{"tls1.0"}) { - return $self->error ("TLS server/client mismatch"); + my $s_framing; + for my $framing_ (split /,/, $framings) { + if (grep $framing_ eq $_, @FRAMINGS) { + $s_framing = $framing_; + last; } - $self->{hdl}->starttls ($self->{tls}, $self->{tls_ctx}); } - # auth - require Digest::MD6; - require Digest::HMAC_MD6; - - my $key = Digest::MD6::md6_hex ($secret); - my $lauth = Digest::HMAC_MD6::hmac_md6_base64 ($key, "$lgreeting$rgreeting", 64, 256); - my $rauth = Digest::HMAC_MD6::hmac_md6_base64 ($key, "$rgreeting$lgreeting", 64, 256); - $self->{hdl}->push_write ("$lauth\012"); + defined $s_framing + or return $self->error ("$framings: no common framing method supported"); + + $self->{remote_uniq} = $uniq; + $self->{remote_node} = $rnode; + $self->{remote_greeting} = { + map /^([^=]+)(?:=(.*))?/ ? ($1 => $2) : (), + @kv + }; + + # read nonce $self->{hdl}->push_read (line => sub { - my ($hdl, $rauth2) = @_; + my $rgreeting2 = $_[1]; - if ($rauth2 ne $rauth) { - return $self->error ("authentication failure/shared secret mismatch"); + if ($self->{tls_ctx} and 1 == int $self->{remote_greeting}{tls}) { + $self->{tls} = $lgreeting2 lt $rgreeting2 ? "connect" : "accept"; + $self->{hdl}->starttls ($self->{tls}, $self->{tls_ctx}); } + + # auth + require Digest::MD6; + require Digest::HMAC_MD6; + + my $key = Digest::MD6::md6 ($secret); + my $lauth = Digest::HMAC_MD6::hmac_md6_hex ($key, "$lgreeting1\012$lgreeting2\012$rgreeting1\012$rgreeting2\012", 64, 256); - my $queue = delete $self->{queue}; # we are connected + my $rauth = + $s_auth eq "hmac_md6_64_256" ? Digest::HMAC_MD6::hmac_md6_hex ($key, "$rgreeting1\012$rgreeting2\012$lgreeting1\012$lgreeting2\012", 64, 256) + : $s_auth eq "cleartext" ? unpack "H*", $secret + : die; - $self->{on_connect}($self) - if $self->{on_connect}; + $lauth ne $rauth # echo attack? + or return $self->error ("authentication error"); - $hdl->push_write (storable => $_) - for @$queue; + $self->{hdl}->push_write ("$s_auth;$lauth;$s_framing\012"); - my $rmsg; $rmsg = sub { - $_[0]->push_read (storable => $rmsg); + # reasd the authentication response + $self->{hdl}->push_read (line => sub { + my ($hdl, $rline) = @_; - $self->{on_recv}($self, $_[1]); - }; - $hdl->push_read (storable => $rmsg); + my ($auth_method, $rauth2, $r_framing) = split /;/, $rline; + + if ($rauth2 ne $rauth) { + return $self->error ("authentication failure/shared secret mismatch"); + } + + $self->{s_framing} = $s_framing; + + $hdl->rbuf_max (undef); + my $queue = delete $self->{queue}; # we are connected + + $self->connected; + + my $src_node = $self->{node}; + + $hdl->push_write ($self->{s_framing} => $_) + for @$queue; + + my $rmsg; $rmsg = sub { + $_[0]->push_read ($r_framing => $rmsg); + + local $AnyEvent::MP::Base::SRCNODE = $src_node; + AnyEvent::MP::Base::_inject (@{ $_[1] }); + }; + $hdl->push_read ($r_framing => $rmsg); + }); }); }); } @@ -200,22 +281,30 @@ sub error { my ($self, $msg) = @_; - $self->{on_error}($self, $msg); - $self->{hdl}->destroy; + if ($self->{node} && $self->{node}{transport} == $self) { + $self->{node}->clr_transport; + } + $AnyEvent::MP::Base::WARN->("$self->{peerhost}:$self->{peerport}: $msg"); + $self->destroy; } -sub send { - my ($self, $msg) = @_; +sub connected { + my ($self) = @_; + + my $node = AnyEvent::MP::Base::add_node ($self->{remote_node}); + Scalar::Util::weaken ($self->{node} = $node); + $node->set_transport ($self); +} - exists $self->{queue} - ? push @{ $self->{queue} }, $msg - : $self->{hdl}->push_write (storable => $msg); +sub send { + $_[0]{hdl}->push_write ($_[0]{s_framing} => $_[1]); } sub destroy { my ($self) = @_; - $self->{hdl}->destroy; + $self->{hdl}->destroy + if $self->{hdl}; } sub DESTROY { @@ -226,6 +315,182 @@ =back +=head1 PROTOCOL + +The protocol is relatively simple, and consists of three phases which are +symmetrical for both sides: greeting (followed by optionally switching to +TLS mode), authentication and packet exchange. + +the protocol is designed to allow both full-text and binary streams. + +The greeting consists of two text lines that are ended by either an ASCII +CR LF pair, or a single ASCII LF (recommended). + +=head2 GREETING + +The first line contains strings separated (not ended) by C<;> +characters. The first even ixtrings are fixed by the protocol, the +remaining strings are C pairs. None of them may contain C<;> +characters themselves. + +All the lines until after authentication must not exceed 4kb in length, including delimiter. + +The fixed strings are: + +=over 4 + +=item C + +The constant C to identify the protocol. + +=item protocol version + +The protocol version supported by this end, currently C<0>. If the +versions don't match then no communication is possible. Minor extensions +are supposed to be handled by addign additional key-value pairs. + +=item a token uniquely identifying the current node instance + +This is a string that must change between restarts. It usually contains +things like the current time, the (OS) process id or similar values, but +no meaning of the contents are assumed. + +=item the node endpoint descriptors + +for public nodes, this is a comma-separated list of protocol endpoints, +i.e., the noderef. For slave nodes, this is a unique identifier. + +=item the acceptable authentication methods + +A comma-separated list of authentication methods supported by the +node. Note that AnyEvent::MP supports a C authentication +method that accepts a cleartext password (hex-encoded), but will not use +this auth method itself. + +The receiving side should choose the first auth method it supports. + +=item the acceptable framing formats + +A comma-separated list of packet encoding/framign formats understood. The +receiving side should choose the first framing format it supports for +sending packets (which might be different from the format it has to accept). + +=back + +The remaining arguments are C pairs. The following key-value +pairs are known at this time: + +=over 4 + +=item provider= + +The software provider for this implementation. For AnyEvent::MP, this is +C or whatever version it currently is at. + +=item peeraddr=: + +The peer address (socket address of the other side) as seen locally, in the same format +as noderef endpoints. + +=item tls=. + +Indicates that the other side supports TLS (version should be 1.0) and +wishes to do a TLS handshake. + +=back + +After this greeting line there will be a second line containing a +cryptographic nonce, i.e. random data of high quality. To keep the +protocol text-only, these are usually 32 base64-encoded octets, but +it could be anything that doesn't contain any ASCII CR or ASCII LF +characters. + +Example of the two lines of greeting: + + aemp;0;fec.4a7720fc;127.0.0.1:1235,[::1]:1235;hmac_md6_64_256;json,storable;provider=AE-0.0 + p/I122ql7kJR8lumW3lXlXCeBnyDAvz8NQo3x5IFowE4 + +=head2 TLS handshake + +If, after the handshake, both sides indicate interest in TLS, then the +connection I use TLS, or fail. + +Both sides compare their nonces, and the side who sent the lower nonce +value ("string" comparison on the raw octet values) becomes the client, +and the one with the higher nonce the server. + +=head2 AUTHENTICATION PHASE + +After the greeting is received (and the optional TLS handshake), +the authentication phase begins, which consists of sending a single +C<;>-separated line with three fixed strings and any number of +C pairs. + +The three fixed strings are: + +=over 4 + +=item the authentication method chosen + +This must be one of the methods offered by the other side in the greeting. + +The currently supported authentication methods are: + +=over 4 + +=item cleartext + +This is simply the shared secret, lowercase-hex-encoded. This method is of +course very insecure, unless TLS is used, which is why this module will +accept, but not generate, cleartext auth replies. + +=item hmac_md6_64_256 + +This method uses an MD6 HMAC with 64 bit blocksize and 256 bit hash. First, the shared secret +is hashed with MD6: + + key = MD6 (secret) + +This secret is then used to generate the "local auth reply", by taking +the two local greeting lines and the two remote greeting lines (without +line endings), appending \012 to all of them, concatenating them and +calculating the MD6 HMAC with the key. + + lauth = HMAC_MD6 key, "lgreeting1\012lgreeting2\012rgreeting1\012rgreeting2\012" + +This authentication token is then lowercase-hex-encoded and sent to the +other side. + +Then the remote auth reply is generated using the same method, but local +and remote greeting lines swapped: + + rauth = HMAC_MD6 key, "rgreeting1\012rgreeting2\012lgreeting1\012lgreeting2\012" + +This is the token that is expected from the other side. + +=back + +=item the authentication data + +The authentication data itself, usually base64 or hex-encoded data, see +above. + +=item the framing protocol chosen + +This must be one of the framing protocols offered by the other side in the +greeting. Each side must accept the choice of the other side. + +=back + +Example: + + hmac_md6_64_256;363d5175df38bd9eaddd3f6ca18aa1c0c4aa22f0da245ac638d048398c26b8d3;json + +=head2 DATA PHASE + +After this, packets get exchanged using the chosen framing protocol. It is +quite possible that both sides use a different framing protocol. + =head1 SEE ALSO L.