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Comparing AnyEvent-MP/MP/Transport.pm (file contents):
Revision 1.8 by root, Mon Aug 3 14:58:13 2009 UTC vs.
Revision 1.22 by root, Wed Aug 5 19:55:58 2009 UTC

1=head1 NAME 1=head1 NAME
2 2
3AnyEvent::MP::Transport - actual transport protocol 3AnyEvent::MP::Transport - actual transport protocol handler
4 4
5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use AnyEvent::MP::Transport; 7 use AnyEvent::MP::Transport;
8 8
9=head1 DESCRIPTION 9=head1 DESCRIPTION
10 10
11This is the superclass for MP transports, most of which is considered an 11This implements the actual transport protocol for MP (it represents a
12implementation detail. 12single link), most of which is considered an implementation detail.
13 13
14See the "PROTOCOL" section below if you want to write another client for 14See the "PROTOCOL" section below if you want to write another client for
15this protocol. 15this protocol.
16 16
17=head1 FUNCTIONS/METHODS 17=head1 FUNCTIONS/METHODS
27use Scalar::Util; 27use Scalar::Util;
28use MIME::Base64 (); 28use MIME::Base64 ();
29use Storable (); 29use Storable ();
30use JSON::XS (); 30use JSON::XS ();
31 31
32use Digest::MD6 ();
33use Digest::HMAC_MD6 ();
34
32use AE (); 35use AE ();
33use AnyEvent::Socket (); 36use AnyEvent::Socket ();
34use AnyEvent::Handle (); 37use AnyEvent::Handle ();
35 38
36use base Exporter::; 39use base Exporter::;
43Creates a listener on the given host/port using 46Creates a listener on the given host/port using
44C<AnyEvent::Socket::tcp_server>. 47C<AnyEvent::Socket::tcp_server>.
45 48
46See C<new>, below, for constructor arguments. 49See C<new>, below, for constructor arguments.
47 50
48Defaults for peerhost, peerport, fh and tls are provided. 51Defaults for peerhost, peerport and fh are provided.
49 52
50=cut 53=cut
51 54
52sub mp_server($$@) { 55sub mp_server($$@) {
53 my $cb = pop; 56 my $cb = pop;
58 61
59 $cb->(new AnyEvent::MP::Transport 62 $cb->(new AnyEvent::MP::Transport
60 fh => $fh, 63 fh => $fh,
61 peerhost => $host, 64 peerhost => $host,
62 peerport => $port, 65 peerport => $port,
63 tls => "accept",
64 @args, 66 @args,
65 ); 67 );
66 } 68 }
67} 69}
68 70
82 $cb->(new AnyEvent::MP::Transport 84 $cb->(new AnyEvent::MP::Transport
83 fh => $fh, 85 fh => $fh,
84 peername => $host, 86 peername => $host,
85 peerhost => $nhost, 87 peerhost => $nhost,
86 peerport => $nport, 88 peerport => $nport,
87 tls => "accept",
88 @args, 89 @args,
89 ); 90 );
90 } 91 }
91} 92}
92 93
105 on_eof => sub { clean-close-callback }, 106 on_eof => sub { clean-close-callback },
106 on_connect => sub { successful-connect-callback }, 107 on_connect => sub { successful-connect-callback },
107 greeting => { key => value }, 108 greeting => { key => value },
108 109
109 # tls support 110 # tls support
110 tls => "accept|connect",
111 tls_ctx => AnyEvent::TLS, 111 tls_ctx => AnyEvent::TLS,
112 peername => $peername, # for verification 112 peername => $peername, # for verification
113 ; 113 ;
114 114
115=cut 115=cut
116 116
117our @FRAMINGS = qw(json storable); # the framing types we accept and send, in order of preference 117our @FRAMINGS = qw(json storable); # the framing types we accept and send, in order of preference
118our @AUTH_SND = qw(hmac_md6_64_256); # auth types we send 118our @AUTH_SND = qw(hmac_md6_64_256); # auth types we send
119our @AUTH_RCV = (@AUTH_SND, qw(hex_secret)); # auth types we accept 119our @AUTH_RCV = (@AUTH_SND, qw(cleartext)); # auth types we accept
120 120
121#AnyEvent::Handle::register_write_type mp_record => sub { 121#AnyEvent::Handle::register_write_type mp_record => sub {
122#}; 122#};
123 123
124sub new { 124sub new {
129 $self->{queue} = []; 129 $self->{queue} = [];
130 130
131 { 131 {
132 Scalar::Util::weaken (my $self = $self); 132 Scalar::Util::weaken (my $self = $self);
133 133
134 if (exists $arg{connect}) {
135 $arg{tls_ctx} ||= { sslv2 => 0, sslv3 => 0, tlsv1 => 1, verify => 1 };
136 }
137
138 $arg{secret} = AnyEvent::MP::Base::default_secret () 134 $arg{secret} = AnyEvent::MP::Base::default_secret ()
139 unless exists $arg{secret}; 135 unless exists $arg{secret};
140 136
137 my $secret = $arg{secret};
138
139 if ($secret =~ /-----BEGIN RSA PRIVATE KEY-----.*-----END RSA PRIVATE KEY-----.*-----BEGIN CERTIFICATE-----.*-----END CERTIFICATE-----/s) {
140 # assume TLS mode
141 $arg{tls_ctx} = {
142 sslv2 => 0,
143 sslv3 => 0,
144 tlsv1 => 1,
145 verify => 1,
146 cert => $secret,
147 ca_cert => $secret,
148 verify_require_client_cert => 1,
149 };
150 }
151
141 $self->{hdl} = new AnyEvent::Handle 152 $self->{hdl} = new AnyEvent::Handle
142 fh => delete $arg{fh}, 153 fh => delete $arg{fh},
143 rbuf_max => 64 * 1024,
144 autocork => 1, 154 autocork => 1,
145 no_delay => 1, 155 no_delay => 1,
146 on_error => sub { 156 on_error => sub {
147 $self->error ($_[2]); 157 $self->error ($_[2]);
148 }, 158 },
149 peername => delete $arg{peername}, 159 peername => delete $arg{peername},
150 ; 160 ;
151 161
152 my $secret = $arg{secret};
153 my $greeting_kv = $self->{greeting} ||= {}; 162 my $greeting_kv = $self->{greeting} ||= {};
154 $greeting_kv->{"tls"} = "1.0" 163 $greeting_kv->{"tls"} = "1.0"
155 if $arg{tls_ctx}; 164 if $arg{tls_ctx};
156 $greeting_kv->{provider} = "AE-$VERSION"; 165 $greeting_kv->{provider} = "AE-$VERSION";
157 $greeting_kv->{peeraddr} = AnyEvent::Socket::format_hostport $self->{peerhost}, $self->{peerport}; 166 $greeting_kv->{peeraddr} = AnyEvent::Socket::format_hostport $self->{peerhost}, $self->{peerport};
158 167
159 # send greeting 168 # send greeting
160 my $lgreeting1 = "aemp;$PROTOCOL_VERSION;$PROTOCOL_VERSION" # version, min 169 my $lgreeting1 = "aemp;$PROTOCOL_VERSION"
161 . ";$AnyEvent::MP::Base::UNIQ" 170 . ";$AnyEvent::MP::Base::UNIQ"
162 . ";$AnyEvent::MP::Base::NODE" 171 . ";$AnyEvent::MP::Base::NODE"
163 . ";" . (join ",", @AUTH_RCV) 172 . ";" . (join ",", @AUTH_RCV)
164 . ";" . (join ",", @FRAMINGS) 173 . ";" . (join ",", @FRAMINGS)
165 . (join "", map ";$_=$greeting_kv->{$_}", keys %$greeting_kv); 174 . (join "", map ";$_=$greeting_kv->{$_}", keys %$greeting_kv);
175
166 my $lgreeting2 = MIME::Base64::encode_base64 AnyEvent::MP::Base::nonce (33), ""; 176 my $lgreeting2 = MIME::Base64::encode_base64 AnyEvent::MP::Base::nonce (33), "";
167 177
168 $self->{hdl}->push_write ("$lgreeting1\012$lgreeting2\012"); 178 $self->{hdl}->push_write ("$lgreeting1\012$lgreeting2\012");
169 179
170 # expect greeting 180 # expect greeting
181 $self->{hdl}->rbuf_max (4 * 1024);
171 $self->{hdl}->push_read (line => sub { 182 $self->{hdl}->push_read (line => sub {
172 my $rgreeting1 = $_[1]; 183 my $rgreeting1 = $_[1];
173 184
174 my ($aemp, $version, $version_min, $uniq, $rnode, $auths, $framings, @kv) = split /;/, $rgreeting1; 185 my ($aemp, $version, $uniq, $rnode, $auths, $framings, @kv) = split /;/, $rgreeting1;
175 186
176 if ($aemp ne "aemp") { 187 if ($aemp ne "aemp") {
177 return $self->error ("unparsable greeting"); 188 return $self->error ("unparsable greeting");
178 } elsif ($version_min > $PROTOCOL_VERSION) { 189 } elsif ($version != $PROTOCOL_VERSION) {
179 return $self->error ("version mismatch (we: $PROTOCOL_VERSION, they: $version_min .. $version)"); 190 return $self->error ("version mismatch (we: $PROTOCOL_VERSION, they: $version)");
180 } 191 }
181 192
182 my $s_auth; 193 my $s_auth;
183 for my $auth_ (split /,/, $auths) { 194 for my $auth_ (split /,/, $auths) {
184 if (grep $auth_ eq $_, @AUTH_SND) { 195 if (grep $auth_ eq $_, @AUTH_SND) {
213 224
214 # read nonce 225 # read nonce
215 $self->{hdl}->push_read (line => sub { 226 $self->{hdl}->push_read (line => sub {
216 my $rgreeting2 = $_[1]; 227 my $rgreeting2 = $_[1];
217 228
229 "$lgreeting1\012$lgreeting2" ne "$rgreeting1\012$rgreeting2" # echo attack?
230 or return $self->error ("authentication error, echo attack?");
231
232 my $key = Digest::MD6::md6 $secret;
233 my $lauth;
234
218 if ($self->{tls_ctx} and 1 == int $self->{remote_greeting}{"tls"}) { 235 if ($self->{tls_ctx} and 1 == int $self->{remote_greeting}{tls}) {
219 $self->{tls} = $lgreeting2 lt $rgreeting2 ? "connect" : "accept"; 236 $self->{tls} = $lgreeting2 lt $rgreeting2 ? "connect" : "accept";
220 $self->{hdl}->starttls ($self->{tls}, $self->{tls_ctx}); 237 $self->{hdl}->starttls ($self->{tls}, $self->{tls_ctx});
238 $s_auth = "tls";
239 $lauth = "";
240 } else {
241 # we currently only support hmac_md6_64_256
242 $lauth = Digest::HMAC_MD6::hmac_md6_hex $key, "$lgreeting1\012$lgreeting2\012$rgreeting1\012$rgreeting2\012", 64, 256;
221 } 243 }
222
223 # auth
224 require Digest::MD6;
225 require Digest::HMAC_MD6;
226
227 my $key = Digest::MD6::md6_hex ($secret);
228 my $lauth = Digest::HMAC_MD6::hmac_md6_base64 ($key, "$lgreeting1\012$lgreeting2\012$rgreeting1\012$rgreeting2\012", 64, 256);
229
230 my $rauth =
231 $s_auth eq "hmac_md6_64_256" ? Digest::HMAC_MD6::hmac_md6_base64 ($key, "$rgreeting1\012$rgreeting2\012$lgreeting1\012$lgreeting2\012", 64, 256)
232 : $s_auth eq "hex_secret" ? unpack "H*", $secret
233 : die;
234
235 $lauth ne $rauth # echo attack?
236 or return $self->error ("authentication error");
237 244
238 $self->{hdl}->push_write ("$s_auth;$lauth;$s_framing\012"); 245 $self->{hdl}->push_write ("$s_auth;$lauth;$s_framing\012");
239 246
240 $self->{hdl}->rbuf_max (64); # enough for 44 reply bytes or so 247 # read the authentication response
241 $self->{hdl}->push_read (line => sub { 248 $self->{hdl}->push_read (line => sub {
242 my ($hdl, $rline) = @_; 249 my ($hdl, $rline) = @_;
243 250
244 my ($auth_method, $rauth2, $r_framing) = split /;/, $rline; 251 my ($auth_method, $rauth2, $r_framing) = split /;/, $rline;
252
253 my $rauth =
254 $auth_method eq "hmac_md6_64_256" ? Digest::HMAC_MD6::hmac_md6_hex $key, "$rgreeting1\012$rgreeting2\012$lgreeting1\012$lgreeting2\012", 64, 256
255 : $auth_method eq "cleartext" ? unpack "H*", $secret
256 : $auth_method eq "tls" ? ($self->{tls} ? "" : "\012\012") # \012\012 never matches
257 : return $self->error ("$auth_method: fatal, selected unsupported auth method");
245 258
246 if ($rauth2 ne $rauth) { 259 if ($rauth2 ne $rauth) {
247 return $self->error ("authentication failure/shared secret mismatch"); 260 return $self->error ("authentication failure/shared secret mismatch");
248 } 261 }
249 262
252 $hdl->rbuf_max (undef); 265 $hdl->rbuf_max (undef);
253 my $queue = delete $self->{queue}; # we are connected 266 my $queue = delete $self->{queue}; # we are connected
254 267
255 $self->connected; 268 $self->connected;
256 269
270 my $src_node = $self->{node};
271
257 $hdl->push_write ($self->{s_framing} => $_) 272 $hdl->push_write ($self->{s_framing} => $_)
258 for @$queue; 273 for @$queue;
259 274
260 my $rmsg; $rmsg = sub { 275 my $rmsg; $rmsg = sub {
261 $_[0]->push_read ($r_framing => $rmsg); 276 $_[0]->push_read ($r_framing => $rmsg);
262 277
278 local $AnyEvent::MP::Base::SRCNODE = $src_node;
263 AnyEvent::MP::Base::_inject ($_[1]); 279 AnyEvent::MP::Base::_inject (@{ $_[1] });
264 }; 280 };
265 $hdl->push_read ($r_framing => $rmsg); 281 $hdl->push_read ($r_framing => $rmsg);
266 }); 282 });
267 }); 283 });
268 }); 284 });
273 289
274sub error { 290sub error {
275 my ($self, $msg) = @_; 291 my ($self, $msg) = @_;
276 292
277 if ($self->{node} && $self->{node}{transport} == $self) { 293 if ($self->{node} && $self->{node}{transport} == $self) {
294 #TODO: store error, but do not instantly fail
295 $self->{node}->fail (transport_error => $self->{node}{noderef}, $msg);
278 $self->{node}->clr_transport; 296 $self->{node}->clr_transport;
279 } 297 }
280 $AnyEvent::MP::Base::WARN->("$self->{peerhost}:$self->{peerport}: $msg"); 298 $AnyEvent::MP::Base::WARN->("$self->{peerhost}:$self->{peerport}: $msg");
281 $self->destroy; 299 $self->destroy;
282} 300}
319The greeting consists of two text lines that are ended by either an ASCII 337The greeting consists of two text lines that are ended by either an ASCII
320CR LF pair, or a single ASCII LF (recommended). 338CR LF pair, or a single ASCII LF (recommended).
321 339
322=head2 GREETING 340=head2 GREETING
323 341
342All the lines until after authentication must not exceed 4kb in length,
343including delimiter. Afterwards there is no limit on the packet size that
344can be received.
345
346=head3 First Greeting Line
347
348Example:
349
350 aemp;0;fec.4a7720fc;127.0.0.1:1235,[::1]:1235;hmac_md6_64_256;json,storable;provider=AE-0.0
351
324The first line contains strings separated (not ended) by C<;> 352The first line contains strings separated (not ended) by C<;>
325characters. The first seven strings are fixed by the protocol, the 353characters. The first even ixtrings are fixed by the protocol, the
326remaining strings are C<KEY=VALUE> pairs. None of them may contain C<;> 354remaining strings are C<KEY=VALUE> pairs. None of them may contain C<;>
327characters themselves. 355characters themselves.
328 356
329The seven fixed strings are: 357The fixed strings are:
330 358
331=over 4 359=over 4
332 360
333=item C<aemp> 361=item protocol identification
334 362
335The constant C<aemp> to identify the protocol. 363The constant C<aemp> to identify the protocol.
336 364
337=item protocol version 365=item protocol version
338 366
339The (maximum) protocol version supported by this end, currently C<0>.
340
341=item minimum protocol version
342
343The minimum protocol version supported by this end, currently C<0>. 367The protocol version supported by this end, currently C<0>. If the
368versions don't match then no communication is possible. Minor extensions
369are supposed to be handled through additional key-value pairs.
344 370
345=item a token uniquely identifying the current node instance 371=item a token uniquely identifying the current node instance
346 372
347This is a string that must change between restarts. It usually contains 373This is a string that must change between restarts. It usually contains
348things like the current time, the (OS) process id or similar values, but 374things like the current time, the (OS) process id or similar values, but
366 392
367A comma-separated list of packet encoding/framign formats understood. The 393A comma-separated list of packet encoding/framign formats understood. The
368receiving side should choose the first framing format it supports for 394receiving side should choose the first framing format it supports for
369sending packets (which might be different from the format it has to accept). 395sending packets (which might be different from the format it has to accept).
370 396
371=cut 397=back
372 398
373The remaining arguments are C<KEY=VALUE> pairs. The following key-value 399The remaining arguments are C<KEY=VALUE> pairs. The following key-value
374pairs are known at this time: 400pairs are known at this time:
375 401
376=over 4 402=over 4
389 415
390Indicates that the other side supports TLS (version should be 1.0) and 416Indicates that the other side supports TLS (version should be 1.0) and
391wishes to do a TLS handshake. 417wishes to do a TLS handshake.
392 418
393=back 419=back
420
421=head3 Second Greeting Line
394 422
395After this greeting line there will be a second line containing a 423After this greeting line there will be a second line containing a
396cryptographic nonce, i.e. random data of high quality. To keep the 424cryptographic nonce, i.e. random data of high quality. To keep the
397protocol text-only, these are usually 32 base64-encoded octets, but 425protocol text-only, these are usually 32 base64-encoded octets, but
398it could be anything that doesn't contain any ASCII CR or ASCII LF 426it could be anything that doesn't contain any ASCII CR or ASCII LF
399characters. 427characters.
400 428
401Example of the two lines of greeting: 429I<< The two nonces B<must> be different, and an aemp implementation
430B<must> check and fail when they are identical >>.
402 431
403 aemp;0;0;e7d.4a76f48f;10.0.0.1:4040;hmac_md6_64_256,hex_secret;json,storable;provider=AE-0.0;peeraddr=127.0.0.1:1235 432Example of a nonce line:
404 XntegV2Guvss0qNn7phCPnoU87xqxV+4Mqm/5y4iQm6a 433
434 p/I122ql7kJR8lumW3lXlXCeBnyDAvz8NQo3x5IFowE4
405 435
406=head2 TLS handshake 436=head2 TLS handshake
407 437
408If, after the handshake, both sides indicate interest in TLS, then the 438I<< If, after the handshake, both sides indicate interest in TLS, then the
409connection I<must> use TLS, or fail. 439connection B<must> use TLS, or fail. >>
410 440
411Both sides compare their nonces, and the side who sent the lower nonce 441Both sides compare their nonces, and the side who sent the lower nonce
412value ("string" comparison on the raw octet values) becomes the client, 442value ("string" comparison on the raw octet values) becomes the client,
413and the one with the higher nonce the server. 443and the one with the higher nonce the server.
414 444
425 455
426=item the authentication method chosen 456=item the authentication method chosen
427 457
428This must be one of the methods offered by the other side in the greeting. 458This must be one of the methods offered by the other side in the greeting.
429 459
460The currently supported authentication methods are:
461
462=over 4
463
464=item cleartext
465
466This is simply the shared secret, lowercase-hex-encoded. This method is of
467course very insecure, unless TLS is used, which is why this module will
468accept, but not generate, cleartext auth replies.
469
470=item hmac_md6_64_256
471
472This method uses an MD6 HMAC with 64 bit blocksize and 256 bit hash. First, the shared secret
473is hashed with MD6:
474
475 key = MD6 (secret)
476
477This secret is then used to generate the "local auth reply", by taking
478the two local greeting lines and the two remote greeting lines (without
479line endings), appending \012 to all of them, concatenating them and
480calculating the MD6 HMAC with the key.
481
482 lauth = HMAC_MD6 key, "lgreeting1\012lgreeting2\012rgreeting1\012rgreeting2\012"
483
484This authentication token is then lowercase-hex-encoded and sent to the
485other side.
486
487Then the remote auth reply is generated using the same method, but local
488and remote greeting lines swapped:
489
490 rauth = HMAC_MD6 key, "rgreeting1\012rgreeting2\012lgreeting1\012lgreeting2\012"
491
492This is the token that is expected from the other side.
493
494=item tls
495
496This type is only valid iff TLS was enabled and the TLS handshake
497was successful. It has no authentication data, as the server/client
498certificate was successfully verified.
499
500Implementations supporting TLS I<must> accept this authentication type.
501
502=back
503
430=item the authentication data 504=item the authentication data
431 505
432The authentication data itself, usually base64 or hex-encoded data. 506The authentication data itself, usually base64 or hex-encoded data, see
507above.
433 508
434=item the framing protocol chosen 509=item the framing protocol chosen
435 510
436This must be one of the framing protocols offered by the other side in the 511This must be one of the framing protocols offered by the other side in the
437greeting. Each side must accept the choice of the other side. 512greeting. Each side must accept the choice of the other side.
438 513
439=back 514=back
440 515
516Example of an authentication reply:
517
518 hmac_md6_64_256;363d5175df38bd9eaddd3f6ca18aa1c0c4aa22f0da245ac638d048398c26b8d3;json
519
441=head2 DATA PHASE 520=head2 DATA PHASE
442 521
443After this, packets get exchanged using the chosen framing protocol. It is 522After this, packets get exchanged using the chosen framing protocol. It is
444quite possible that both sides use a different framing protocol. 523quite possible that both sides use a different framing protocol.
445 524
525=head2 FULL EXAMPLE
526
527This is an actual protocol dump of a handshake, followed by a single data
528packet. The greater than/less than lines indicate the direction of the
529transfer only.
530
531 > aemp;0;nndKd+gn;10.0.0.1:4040;hmac_md6_64_256,cleartext;json,storable;provider=AE-0.0;peeraddr=127.0.0.1:1235
532 > sRG8bbc4TDbkpvH8FTP4HBs87OhepH6VuApoZqXXskuG
533 < aemp;0;nmpKd+gh;127.0.0.1:1235,[::1]:1235;hmac_md6_64_256,cleartext;json,storable;provider=AE-0.0;peeraddr=127.0.0.1:58760
534 < dCEUcL/LJVSTJcx8byEsOzrwhzJYOq+L3YcopA5T6EAo
535 > hmac_md6_64_256;9513d4b258975accfcb2ab7532b83690e9c119a502c612203332a591c7237788;json
536 < hmac_md6_64_256;0298d6ba2240faabb2b2e881cf86b97d70a113ca74a87dc006f9f1e9d3010f90;json
537 > ["","lookup","pinger","10.0.0.1:4040#nndKd+gn.a","resolved"]
538
446=head1 SEE ALSO 539=head1 SEE ALSO
447 540
448L<AnyEvent>. 541L<AnyEvent>.
449 542
450=head1 AUTHOR 543=head1 AUTHOR

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