Annotation of loncom/LondConnection.pm, revision 1.46
1.2 albertel 1: # This module defines and implements a class that represents
2: # a connection to a lond daemon.
3: #
1.46 ! albertel 4: # $Id: LondConnection.pm,v 1.45 2007/04/03 01:08:05 albertel Exp $
1.2 albertel 5: #
6: # Copyright Michigan State University Board of Trustees
7: #
8: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
9: #
10: # LON-CAPA is free software; you can redistribute it and/or modify
11: # it under the terms of the GNU General Public License as published by
12: # the Free Software Foundation; either version 2 of the License, or
13: # (at your option) any later version.
14: #
15: # LON-CAPA is distributed in the hope that it will be useful,
16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18: # GNU General Public License for more details.
19: #
20: # You should have received a copy of the GNU General Public License
21: # along with LON-CAPA; if not, write to the Free Software
22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23: #
24: # /home/httpd/html/adm/gpl.txt
25: #
26: # http://www.lon-capa.org/
1.1 foxr 27: #
1.14 foxr 28:
1.1 foxr 29: package LondConnection;
30:
1.10 foxr 31: use strict;
1.1 foxr 32: use IO::Socket;
33: use IO::Socket::INET;
34: use IO::Handle;
35: use IO::File;
36: use Fcntl;
37: use POSIX;
38: use Crypt::IDEA;
1.31 foxr 39: use LONCAPA::lonlocal;
40: use LONCAPA::lonssl;
1.14 foxr 41:
1.1 foxr 42:
1.12 foxr 43:
44:
1.32 foxr 45: my $DebugLevel=0;
1.12 foxr 46: my %perlvar;
1.31 foxr 47: my $InsecureOk;
1.1 foxr 48:
1.14 foxr 49: #
1.16 foxr 50: # Set debugging level
51: #
52: sub SetDebug {
53: $DebugLevel = shift;
54: }
55:
56: #
1.14 foxr 57: # The config read is done in this way to support the read of
58: # the non-default configuration file in the
59: # event we are being used outside of loncapa.
60: #
61:
62: my $ConfigRead = 0;
63:
1.1 foxr 64: # Read the configuration file for apache to get the perl
1.31 foxr 65: # variables set.
1.1 foxr 66:
1.12 foxr 67: sub ReadConfig {
1.31 foxr 68: Debug(8, "ReadConfig called");
69:
1.14 foxr 70: my $perlvarref = read_conf('loncapa.conf');
1.12 foxr 71: %perlvar = %{$perlvarref};
1.17 foxr 72: $ConfigRead = 1;
1.12 foxr 73:
1.31 foxr 74: $InsecureOk = $perlvar{loncAllowInsecure};
1.15 foxr 75: }
1.1 foxr 76:
77: sub Debug {
1.30 foxr 78:
79: my ($level, $message) = @_;
80:
1.1 foxr 81: if ($level < $DebugLevel) {
1.31 foxr 82: print STDERR ($message."\n");
1.1 foxr 83: }
84: }
1.3 albertel 85:
86: =pod
87:
88: =head2 Dump
89:
1.12 foxr 90: Dump the internal state of the object: For debugging purposes, to stderr.
1.3 albertel 91:
1.1 foxr 92: =cut
93:
94: sub Dump {
95: my $self = shift;
1.32 foxr 96: my $level = shift;
1.35 foxr 97: my $now = time;
98: my $local = localtime($now);
1.32 foxr 99:
1.37 albertel 100: if ($level >= $DebugLevel) {
1.32 foxr 101: return;
102: }
103:
1.35 foxr 104:
1.10 foxr 105: my $key;
106: my $value;
1.35 foxr 107: print STDERR "[ $local ] Dumping LondConnectionObject:\n";
1.37 albertel 108: print STDERR join(':',caller(1))."\n";
1.1 foxr 109: while(($key, $value) = each %$self) {
1.22 foxr 110: print STDERR "$key -> $value\n";
1.1 foxr 111: }
1.23 foxr 112: print STDERR "-------------------------------\n";
1.1 foxr 113: }
114:
115: =pod
1.3 albertel 116:
117: Local function to do a state transition. If the state transition
118: callback is defined it is called with two parameters: the self and the
119: old state.
120:
1.1 foxr 121: =cut
1.3 albertel 122:
1.1 foxr 123: sub Transition {
1.30 foxr 124:
125: my ($self, $newstate) = @_;
126:
1.1 foxr 127: my $oldstate = $self->{State};
128: $self->{State} = $newstate;
129: $self->{TimeoutRemaining} = $self->{TimeoutValue};
130: if($self->{TransitionCallback}) {
131: ($self->{TransitionCallback})->($self, $oldstate);
132: }
133: }
134:
1.3 albertel 135:
1.14 foxr 136:
1.1 foxr 137: =pod
1.3 albertel 138:
139: =head2 new
140:
141: Construct a new lond connection.
142:
143: Parameters (besides the class name) include:
144:
145: =item hostname
146:
147: host the remote lond is on. This host is a host in the hosts.tab file
148:
149: =item port
150:
151: port number the remote lond is listening on.
152:
1.1 foxr 153: =cut
1.3 albertel 154:
1.1 foxr 155: sub new {
1.44 albertel 156: my ($class, $DnsName, $Port, $lonid) = @_;
1.14 foxr 157:
158: if (!$ConfigRead) {
159: ReadConfig();
160: $ConfigRead = 1;
161: }
1.45 albertel 162: &Debug(4,$class."::new( ".$DnsName.",".$Port.",".$lonid.")\n");
1.1 foxr 163:
164: # The host must map to an entry in the hosts table:
165: # We connect to the dns host that corresponds to that
166: # system and use the hostname for the encryption key
167: # negotion. In the objec these become the Host and
168: # LoncapaHim fields of the object respectively.
169: #
1.36 albertel 170: # if it is me use loopback for connection
1.44 albertel 171: if ($DnsName eq &main::my_hostname()) { $DnsName="127.0.0.1"; }
172: Debug(9, "Connecting to $DnsName");
1.1 foxr 173: # Now create the object...
174: my $self = { Host => $DnsName,
1.44 albertel 175: LoncapaHim => $lonid,
1.24 foxr 176: Port => $Port,
177: State => "Initialized",
1.31 foxr 178: AuthenticationMode => "",
1.24 foxr 179: TransactionRequest => "",
180: TransactionReply => "",
1.39 albertel 181: NextRequest => "",
1.24 foxr 182: InformReadable => 0,
183: InformWritable => 0,
184: TimeoutCallback => undef,
185: TransitionCallback => undef,
186: Timeoutable => 0,
1.46 ! albertel 187: TimeoutValue => 30,
1.24 foxr 188: TimeoutRemaining => 0,
1.31 foxr 189: LocalKeyFile => "",
1.24 foxr 190: CipherKey => "",
191: LondVersion => "Unknown",
192: Cipher => undef};
1.1 foxr 193: bless($self, $class);
194: unless ($self->{Socket} = IO::Socket::INET->new(PeerHost => $self->{Host},
1.27 foxr 195: PeerPort => $self->{Port},
196: Type => SOCK_STREAM,
197: Proto => "tcp",
198: Timeout => 3)) {
1.36 albertel 199: Debug(8, "Error? \n$@ \n$!");
1.1 foxr 200: return undef; # Inidicates the socket could not be made.
201: }
1.31 foxr 202: my $socket = $self->{Socket}; # For local use only.
1.33 foxr 203: # If we are local, we'll first try local auth mode, otherwise, we'll try
204: # the ssl auth mode:
1.31 foxr 205:
206: my $key;
207: my $keyfile;
1.36 albertel 208: if ($DnsName eq '127.0.0.1') {
1.31 foxr 209: $self->{AuthenticationMode} = "local";
210: ($key, $keyfile) = lonlocal::CreateKeyFile();
211: Debug(8, "Local key: $key, stored in $keyfile");
212:
213: # If I can't make the key file fall back to insecure if
214: # allowed...else give up right away.
215:
216: if(!(defined $key) || !(defined $keyfile)) {
217: if($InsecureOk) {
218: $self->{AuthenticationMode} = "insecure";
219: $self->{TransactionRequest} = "init\n";
220: }
221: else {
222: $socket->close;
223: return undef;
224: }
225: }
226: $self->{TransactionRequest} = "init:local:$keyfile\n";
227: Debug(9, "Init string is init:local:$keyfile");
228: if(!$self->CreateCipher($key)) { # Nothing's going our way...
229: $socket->close;
230: return undef;
231: }
232:
1.42 albertel 233: } else {
1.33 foxr 234: # Remote peer: I'd like to do ssl, but if my host key or certificates
235: # are not all installed, my only choice is insecure, if that's
236: # allowed:
237:
238: my ($ca, $cert) = lonssl::CertificateFile;
239: my $sslkeyfile = lonssl::KeyFile;
240:
241: if((defined $ca) && (defined $cert) && (defined $sslkeyfile)) {
242:
243: $self->{AuthenticationMode} = "ssl";
244: $self->{TransactionRequest} = "init:ssl\n";
245: } else {
246: if($InsecureOk) { # Allowed to do insecure:
247: $self->{AuthenticationMode} = "insecure";
248: $self->{TransactionRequest} = "init\n";
249: }
250: else { # Not allowed to do insecure...
251: $socket->close;
252: return undef;
253: }
254: }
1.31 foxr 255: }
256:
1.1 foxr 257: #
258: # We're connected. Set the state, and the events we'll accept:
259: #
260: $self->Transition("Connected");
261: $self->{InformWritable} = 1; # When socket is writable we send init
1.9 foxr 262: $self->{Timeoutable} = 1; # Timeout allowed during startup negotiation.
1.31 foxr 263:
1.1 foxr 264:
265: #
266: # Set socket to nonblocking I/O.
267: #
1.31 foxr 268: my $flags = fcntl($socket, F_GETFL,0);
269: if(!$flags) {
1.1 foxr 270: $socket->close;
271: return undef;
272: }
1.31 foxr 273: if(!fcntl($socket, F_SETFL, $flags | O_NONBLOCK)) {
1.1 foxr 274: $socket->close;
275: return undef;
276: }
277:
278: # return the object :
279:
1.31 foxr 280: Debug(9, "Initial object state: ");
1.32 foxr 281: $self->Dump(9);
1.31 foxr 282:
1.1 foxr 283: return $self;
284: }
1.3 albertel 285:
1.1 foxr 286: =pod
1.3 albertel 287:
288: =head2 Readable
289:
290: This member should be called when the Socket becomes readable. Until
291: the read completes, action is state independet. Data are accepted into
292: the TransactionReply until a newline character is received. At that
293: time actionis state dependent:
294:
295: =item Connected
296:
297: in this case we received challenge, the state changes to
298: ChallengeReceived, and we initiate a send with the challenge response.
299:
300: =item ReceivingReply
301:
302: In this case a reply has been received for a transaction, the state
303: goes to Idle and we disable write and read notification.
304:
305: =item ChallengeReeived
306:
307: we just got what should be an ok\n and the connection can now handle
308: transactions.
1.1 foxr 309:
310: =cut
1.3 albertel 311:
1.1 foxr 312: sub Readable {
313: my $self = shift;
314: my $socket = $self->{Socket};
315: my $data = '';
1.27 foxr 316: my $rv;
1.31 foxr 317: my $ConnectionMode = $self->{AuthenticationMode};
318:
1.27 foxr 319: if ($socket) {
320: eval {
321: $rv = $socket->recv($data, POSIX::BUFSIZ, 0);
322: }
323: } else {
324: $self->Transition("Disconnected");
325: return -1;
326: }
1.1 foxr 327: my $errno = $! + 0; # Force numeric context.
328:
1.8 foxr 329: unless (defined($rv) && length $data) {# Read failed,
1.1 foxr 330: if(($errno == POSIX::EWOULDBLOCK) ||
331: ($errno == POSIX::EAGAIN) ||
1.8 foxr 332: ($errno == POSIX::EINTR)) {
1.1 foxr 333: return 0;
334: }
335:
336: # Connection likely lost.
337: &Debug(4, "Connection lost");
338: $self->{TransactionRequest} = '';
339: $socket->close();
340: $self->Transition("Disconnected");
341: return -1;
342: }
343: # Append the data to the buffer. And figure out if the read is done:
344:
345: &Debug(9,"Received from host: ".$data);
346: $self->{TransactionReply} .= $data;
1.29 albertel 347: if($self->{TransactionReply} =~ m/\n$/) {
1.1 foxr 348: &Debug(8,"Readable End of line detected");
1.31 foxr 349:
350:
1.1 foxr 351: if ($self->{State} eq "Initialized") { # We received the challenge:
1.31 foxr 352: # Our init was replied to. What happens next depends both on
353: # the actual init we sent (AuthenticationMode member data)
354: # and the response:
355: # AuthenticationMode == local:
356: # Response ok: The key has been exchanged and
357: # the key file destroyed. We can jump
358: # into setting the host and requesting the
359: # Later we'll also bypass key exchange.
360: # Response digits:
361: # Old style lond. Delete the keyfile.
362: # If allowed fall back to insecure mode.
363: # else close connection and fail.
364: # Response other:
365: # Failed local auth
366: # Close connection and fail.
367: #
368: # AuthenticationMode == ssl:
369: # Response ok:ssl
370: # Response digits:
371: # Response other:
372: # Authentication mode == insecure
373: # Response digits
374: # Response other:
375:
376: my $Response = $self->{TransactionReply};
377: if($ConnectionMode eq "local") {
378: if($Response =~ /^ok:local/) { # Good local auth.
379: $self->ToVersionRequest();
380: return 0;
381: }
382: elsif ($Response =~/^[0-9]+/) { # Old style lond.
383: return $self->CompleteInsecure();
384:
385: }
386: else { # Complete flop
387: &Debug(3, "init:local : unrecognized reply");
388: $self->Transition("Disconnected");
389: $socket->close;
390: return -1;
391: }
392: }
393: elsif ($ConnectionMode eq "ssl") {
394: if($Response =~ /^ok:ssl/) { # Good ssl...
395: if($self->ExchangeKeysViaSSL()) { # Success skip to vsn stuff
396: # Need to reset to non blocking:
397:
398: my $flags = fcntl($socket, F_GETFL, 0);
399: fcntl($socket, F_SETFL, $flags | O_NONBLOCK);
400: $self->ToVersionRequest();
401: return 0;
402: }
403: else { # Failed in ssl exchange.
404: &Debug(3,"init:ssl failed key negotiation!");
405: $self->Transition("Disconnected");
406: $socket->close;
407: return -1;
408: }
409: }
410: elsif ($Response =~ /^[0-9]+/) { # Old style lond.
411: return $self->CompleteInsecure();
412: }
413: else { # Complete flop
414: }
415: }
416: elsif ($ConnectionMode eq "insecure") {
417: if($self->{TransactionReply} eq "refused\n") { # Remote doesn't have
418:
419: $self->Transition("Disconnected"); # in host tables.
420: $socket->close();
421: return -1;
422:
423: }
424: return $self->CompleteInsecure();
425: }
426: else {
427: &Debug(1,"Authentication mode incorrect");
428: die "BUG!!! LondConnection::Readable invalid authmode";
1.1 foxr 429: }
1.27 foxr 430:
1.31 foxr 431:
1.28 albertel 432: } elsif ($self->{State} eq "ChallengeReplied") {
433: if($self->{TransactionReply} ne "ok\n") {
434: $self->Transition("Disconnected");
435: $socket->close();
436: return -1;
437: }
1.31 foxr 438: $self->ToVersionRequest();
1.28 albertel 439: return 0;
1.31 foxr 440:
1.28 albertel 441: } elsif ($self->{State} eq "ReadingVersionString") {
1.38 albertel 442: chomp($self->{TransactionReply});
443: $self->{LondVersion} = $self->{TransactionReply};
1.28 albertel 444: $self->Transition("SetHost");
445: $self->{InformReadable} = 0;
446: $self->{InformWritable} = 1;
447: my $peer = $self->{LoncapaHim};
448: $self->{TransactionRequest}= "sethost:$peer\n";
449: return 0;
1.24 foxr 450: } elsif ($self->{State} eq "HostSet") { # should be ok.
1.28 albertel 451: if($self->{TransactionReply} ne "ok\n") {
452: $self->Transition("Disconnected");
453: $socket->close();
454: return -1;
455: }
1.31 foxr 456: # If the auth mode is insecure we must still
457: # exchange session keys. Otherwise,
458: # we can just transition to idle.
459:
460: if($ConnectionMode eq "insecure") {
461: $self->Transition("RequestingKey");
462: $self->{InformReadable} = 0;
463: $self->{InformWritable} = 1;
464: $self->{TransactionRequest} = "ekey\n";
465: return 0;
466: }
467: else {
468: $self->ToIdle();
469: return 0;
470: }
1.1 foxr 471: } elsif ($self->{State} eq "ReceivingKey") {
472: my $buildkey = $self->{TransactionReply};
473: my $key = $self->{LoncapaHim}.$perlvar{'lonHostID'};
474: $key=~tr/a-z/A-Z/;
475: $key=~tr/G-P/0-9/;
476: $key=~tr/Q-Z/0-9/;
1.31 foxr 477: $key =$key.$buildkey.$key.$buildkey.$key.$buildkey;
478: $key = substr($key,0,32);
479: if(!$self->CreateCipher($key)) {
1.1 foxr 480: $self->Transition("Disconnected");
481: $socket->close();
482: return -1;
483: } else {
1.31 foxr 484: $self->ToIdle();
1.1 foxr 485: return 0;
486: }
487: } elsif ($self->{State} eq "ReceivingReply") {
488:
489: # If the data are encrypted, decrypt first.
490:
491: my $answer = $self->{TransactionReply};
492: if($answer =~ /^enc\:/) {
493: $answer = $self->Decrypt($answer);
1.34 foxr 494: $self->{TransactionReply} = "$answer\n";
1.1 foxr 495: }
1.39 albertel 496: # if we have a NextRequest do it immeadiately
497: if ($self->{NextRequest}) {
498: $self->{TransactionRequest} = $self->{NextRequest};
499: undef( $self->{NextRequest} );
500: $self->{TransactionReply} = "";
501: $self->{InformWritable} = 1;
502: $self->{InformReadable} = 0;
503: $self->{Timeoutable} = 1;
504: $self->{TimeoutRemaining} = $self->{TimeoutValue};
505: $self->Transition("SendingRequest");
506: return 0;
507: } else {
1.1 foxr 508: # finish the transaction
509:
1.39 albertel 510: $self->ToIdle();
511: return 0;
512: }
1.1 foxr 513: } elsif ($self->{State} eq "Disconnected") { # No connection.
514: return -1;
515: } else { # Internal error: Invalid state.
516: $self->Transition("Disconnected");
517: $socket->close();
518: return -1;
519: }
520: }
521:
522: return 0;
1.27 foxr 523:
1.1 foxr 524: }
525:
526:
527: =pod
1.3 albertel 528:
529: This member should be called when the Socket becomes writable.
530:
531: The action is state independent. An attempt is made to drain the
532: contents of the TransactionRequest member. Once this is drained, we
533: mark the object as waiting for readability.
1.1 foxr 534:
535: Returns 0 if successful, or -1 if not.
1.3 albertel 536:
1.1 foxr 537: =cut
538: sub Writable {
539: my $self = shift; # Get reference to the object.
540: my $socket = $self->{Socket};
1.26 albertel 541: my $nwritten;
542: if ($socket) {
543: eval {
544: $nwritten = $socket->send($self->{TransactionRequest}, 0);
545: }
1.27 foxr 546: } else {
547: # For whatever reason, there's no longer a socket left.
548:
549:
550: $self->Transition("Disconnected");
551: return -1;
1.26 albertel 552: }
1.1 foxr 553: my $errno = $! + 0;
554: unless (defined $nwritten) {
555: if($errno != POSIX::EINTR) {
556: $self->Transition("Disconnected");
557: return -1;
558: }
559:
560: }
1.10 foxr 561: if (($nwritten >= 0) ||
1.1 foxr 562: ($errno == POSIX::EWOULDBLOCK) ||
563: ($errno == POSIX::EAGAIN) ||
564: ($errno == POSIX::EINTR) ||
565: ($errno == 0)) {
566: substr($self->{TransactionRequest}, 0, $nwritten) = ""; # rmv written part
1.27 foxr 567: if(length $self->{TransactionRequest} == 0) {
568: $self->{InformWritable} = 0;
569: $self->{InformReadable} = 1;
570: $self->{TransactionReply} = '';
571: #
572: # Figure out the next state:
573: #
574: if($self->{State} eq "Connected") {
575: $self->Transition("Initialized");
576: } elsif($self->{State} eq "ChallengeReceived") {
577: $self->Transition("ChallengeReplied");
578: } elsif($self->{State} eq "RequestingVersion") {
579: $self->Transition("ReadingVersionString");
580: } elsif ($self->{State} eq "SetHost") {
581: $self->Transition("HostSet");
582: } elsif($self->{State} eq "RequestingKey") {
583: $self->Transition("ReceivingKey");
1.24 foxr 584: # $self->{InformWritable} = 0;
585: # $self->{InformReadable} = 1;
586: # $self->{TransactionReply} = '';
1.27 foxr 587: } elsif ($self->{State} eq "SendingRequest") {
588: $self->Transition("ReceivingReply");
589: $self->{TimeoutRemaining} = $self->{TimeoutValue};
590: } elsif ($self->{State} eq "Disconnected") {
591: return -1;
592: }
593: return 0;
594: }
595: } else { # The write failed (e.g. partner disconnected).
596: $self->Transition("Disconnected");
597: $socket->close();
598: return -1;
599: }
600:
1.1 foxr 601: }
602: =pod
1.3 albertel 603:
604: =head2 Tick
605:
1.1 foxr 606: Tick is called every time unit by the event framework. It
1.3 albertel 607:
608: =item 1 decrements the remaining timeout.
609:
610: =item 2 If the timeout is zero, calls TimedOut indicating that the current operation timed out.
1.1 foxr 611:
612: =cut
613:
614: sub Tick {
615: my $self = shift;
616: $self->{TimeoutRemaining}--;
617: if ($self->{TimeoutRemaining} < 0) {
618: $self->TimedOut();
619: }
620: }
1.3 albertel 621:
1.1 foxr 622: =pod
623:
1.3 albertel 624: =head2 TimedOut
625:
626: called on a timeout. If the timeout callback is defined, it is called
627: with $self as its parameters.
628:
629: =cut
630:
1.1 foxr 631: sub TimedOut {
632:
633: my $self = shift;
634: if($self->{TimeoutCallback}) {
635: my $callback = $self->{TimeoutCallback};
636: my @args = ( $self);
637: &$callback(@args);
638: }
639: }
1.3 albertel 640:
1.1 foxr 641: =pod
1.3 albertel 642:
643: =head2 InitiateTransaction
644:
645: Called to initiate a transaction. A transaction can only be initiated
646: when the object is idle... otherwise an error is returned. A
647: transaction consists of a request to the server that will have a
648: reply. This member sets the request data in the TransactionRequest
649: member, makes the state SendingRequest and sets the data to allow a
650: timout, and to request writability notification.
651:
1.1 foxr 652: =cut
1.3 albertel 653:
1.1 foxr 654: sub InitiateTransaction {
1.30 foxr 655:
656: my ($self, $data) = @_;
1.1 foxr 657:
1.4 foxr 658: Debug(1, "initiating transaction: ".$data);
1.1 foxr 659: if($self->{State} ne "Idle") {
1.4 foxr 660: Debug(0," .. but not idle here\n");
1.1 foxr 661: return -1; # Error indicator.
662: }
663: # if the transaction is to be encrypted encrypt the data:
1.39 albertel 664: (my $sethost, my $server,$data)=split(/:/,$data,3);
1.1 foxr 665:
666: if($data =~ /^encrypt\:/) {
667: $data = $self->Encrypt($data);
668: }
669:
670: # Setup the trasaction
1.39 albertel 671: # currently no version of lond supports inlining the sethost
1.40 albertel 672: if ($self->PeerVersion() <= 321) {
1.39 albertel 673: if ($server ne $self->{LoncapaHim}) {
674: $self->{NextRequest} = $data;
675: $self->{TransactionRequest} = "$sethost:$server\n";
676: $self->{LoncapaHim} = $server;
677: } else {
678: $self->{TransactionRequest} = $data;
679: }
680: } else {
1.40 albertel 681: $self->{LoncapaHim} = $server;
1.39 albertel 682: $self->{TransactionRequest} = "$sethost:$server:$data";
683: }
1.1 foxr 684: $self->{TransactionReply} = "";
685: $self->{InformWritable} = 1;
686: $self->{InformReadable} = 0;
687: $self->{Timeoutable} = 1;
688: $self->{TimeoutRemaining} = $self->{TimeoutValue};
689: $self->Transition("SendingRequest");
690: }
691:
692:
693: =pod
1.3 albertel 694:
695: =head2 SetStateTransitionCallback
696:
697: Sets a callback for state transitions. Returns a reference to any
698: prior established callback, or undef if there was none:
699:
1.1 foxr 700: =cut
1.3 albertel 701:
1.1 foxr 702: sub SetStateTransitionCallback {
703: my $self = shift;
704: my $oldCallback = $self->{TransitionCallback};
705: $self->{TransitionCallback} = shift;
706: return $oldCallback;
707: }
1.3 albertel 708:
1.1 foxr 709: =pod
1.3 albertel 710:
711: =head2 SetTimeoutCallback
712:
713: Sets the timeout callback. Returns a reference to any prior
714: established callback or undef if there was none.
715:
1.1 foxr 716: =cut
1.3 albertel 717:
1.1 foxr 718: sub SetTimeoutCallback {
1.30 foxr 719:
720: my ($self, $callback) = @_;
721:
1.1 foxr 722: my $oldCallback = $self->{TimeoutCallback};
723: $self->{TimeoutCallback} = $callback;
724: return $oldCallback;
725: }
726:
727: =pod
1.3 albertel 728:
1.5 foxr 729: =head2 Shutdown:
730:
731: Shuts down the socket.
732:
733: =cut
734:
735: sub Shutdown {
736: my $self = shift;
737: my $socket = $self->GetSocket();
1.20 albertel 738: Debug(5,"socket is -$socket-");
739: if ($socket) {
740: # Ask lond to exit too. Non blocking so
741: # there is no cost for failure.
742: eval {
743: $socket->send("exit\n", 0);
744: $socket->shutdown(2);
745: }
746: }
1.5 foxr 747: }
748:
749: =pod
750:
1.3 albertel 751: =head2 GetState
752:
753: selector for the object state.
754:
1.1 foxr 755: =cut
1.3 albertel 756:
1.1 foxr 757: sub GetState {
758: my $self = shift;
759: return $self->{State};
760: }
1.3 albertel 761:
1.1 foxr 762: =pod
1.3 albertel 763:
764: =head2 GetSocket
765:
766: selector for the object socket.
767:
1.1 foxr 768: =cut
1.3 albertel 769:
1.1 foxr 770: sub GetSocket {
771: my $self = shift;
772: return $self->{Socket};
773: }
1.3 albertel 774:
1.5 foxr 775:
1.1 foxr 776: =pod
1.3 albertel 777:
778: =head2 WantReadable
779:
780: Return the state of the flag that indicates the object wants to be
781: called when readable.
782:
1.1 foxr 783: =cut
1.3 albertel 784:
1.1 foxr 785: sub WantReadable {
786: my $self = shift;
787:
788: return $self->{InformReadable};
789: }
1.3 albertel 790:
1.1 foxr 791: =pod
1.3 albertel 792:
793: =head2 WantWritable
794:
795: Return the state of the flag that indicates the object wants write
796: notification.
797:
1.1 foxr 798: =cut
1.3 albertel 799:
1.1 foxr 800: sub WantWritable {
801: my $self = shift;
802: return $self->{InformWritable};
803: }
1.3 albertel 804:
1.1 foxr 805: =pod
1.3 albertel 806:
807: =head2 WantTimeout
808:
809: return the state of the flag that indicates the object wants to be
810: informed of timeouts.
811:
1.1 foxr 812: =cut
1.3 albertel 813:
1.1 foxr 814: sub WantTimeout {
815: my $self = shift;
816: return $self->{Timeoutable};
817: }
818:
819: =pod
1.3 albertel 820:
821: =head2 GetReply
822:
823: Returns the reply from the last transaction.
824:
1.1 foxr 825: =cut
1.3 albertel 826:
1.1 foxr 827: sub GetReply {
828: my $self = shift;
829: return $self->{TransactionReply};
830: }
831:
832: =pod
1.3 albertel 833:
834: =head2 Encrypt
835:
836: Returns the encrypted version of the command string.
837:
838: The command input string is of the form:
839:
1.1 foxr 840: encrypt:command
1.3 albertel 841:
842: The output string can be directly sent to lond as it is of the form:
843:
1.1 foxr 844: enc:length:<encodedrequest>
1.3 albertel 845:
1.1 foxr 846: =cut
1.3 albertel 847:
1.1 foxr 848: sub Encrypt {
1.30 foxr 849:
850: my ($self, $request) = @_;
1.1 foxr 851:
852:
853: # Split the encrypt: off the request and figure out it's length.
854: # the cipher works in blocks of 8 bytes.
855:
856: my $cmd = $request;
857: $cmd =~ s/^encrypt\://; # strip off encrypt:
858: chomp($cmd); # strip off trailing \n
859: my $length=length($cmd); # Get the string length.
860: $cmd .= " "; # Pad with blanks so we can fill out a block.
861:
862: # encrypt the request in 8 byte chunks to create the encrypted
863: # output request.
864:
865: my $Encoded = '';
866: for(my $index = 0; $index <= $length; $index += 8) {
867: $Encoded .=
868: unpack("H16",
869: $self->{Cipher}->encrypt(substr($cmd,
870: $index, 8)));
871: }
872:
873: # Build up the answer as enc:length:$encrequest.
874:
875: $request = "enc:$length:$Encoded\n";
876: return $request;
877:
878:
879: }
1.3 albertel 880:
881: =pod
882:
883: =head2 Decrypt
884:
885: Decrypt a response from the server. The response is in the form:
886:
887: enc:<length>:<encrypted data>
888:
1.1 foxr 889: =cut
1.3 albertel 890:
1.1 foxr 891: sub Decrypt {
1.30 foxr 892:
893: my ($self, $encrypted) = @_;
1.1 foxr 894:
895: # Bust up the response into length, and encryptedstring:
896:
897: my ($enc, $length, $EncryptedString) = split(/:/,$encrypted);
898: chomp($EncryptedString);
899:
900: # Decode the data in 8 byte blocks. The string is encoded
901: # as hex digits so there are two characters per byte:
902:
1.10 foxr 903: my $decrypted = "";
1.1 foxr 904: for(my $index = 0; $index < length($EncryptedString);
905: $index += 16) {
906: $decrypted .= $self->{Cipher}->decrypt(
907: pack("H16",
908: substr($EncryptedString,
909: $index,
910: 16)));
911: }
912: # the answer may have trailing pads to fill out a block.
913: # $length tells us the actual length of the decrypted string:
914:
915: $decrypted = substr($decrypted, 0, $length);
1.34 foxr 916: Debug(9, "Decrypted $EncryptedString to $decrypted");
1.1 foxr 917:
918: return $decrypted;
919:
920: }
1.31 foxr 921: # ToIdle
922: # Called to transition to idle... done enough it's worth subbing
923: # off to ensure it's always done right!!
924: #
925: sub ToIdle {
926: my $self = shift;
927:
928: $self->Transition("Idle");
929: $self->{InformWritiable} = 0;
930: $self->{InformReadable} = 0;
931: $self->{Timeoutable} = 0;
932: }
933:
934: # ToVersionRequest
935: # Called to transition to "RequestVersion" also done a few times
936: # so worth subbing out.
937: #
938: sub ToVersionRequest {
939: my $self = shift;
940:
941: $self->Transition("RequestingVersion");
942: $self->{InformReadable} = 0;
943: $self->{InformWritable} = 1;
944: $self->{TransactionRequest} = "version\n";
945:
946: }
947: #
948: # CreateCipher
949: # Given a cipher key stores the key in the object context,
950: # creates the cipher object, (stores that in object context),
951: # This is done a couple of places, so it's worth factoring it out.
952: #
953: # Parameters:
954: # (self)
955: # key - The Cipher key.
956: #
957: # Returns:
958: # 0 - Failure to create IDEA cipher.
959: # 1 - Success.
960: #
961: sub CreateCipher {
962: my ($self, $key) = @_; # According to coding std.
963:
964: $self->{CipherKey} = $key; # Save the text key...
965: my $packedkey = pack ("H32", $key);
966: my $cipher = new IDEA $packedkey;
967: if($cipher) {
968: $self->{Cipher} = $cipher;
969: Debug("Cipher created dumping socket: ");
1.32 foxr 970: $self->Dump(9);
1.31 foxr 971: return 1;
972: }
973: else {
974: return 0;
975: }
976: }
977: # ExchangeKeysViaSSL
978: # Called to do cipher key exchange via SSL.
979: # The socket is promoted to an SSL socket. If that's successful,
980: # we read out cipher key through the socket and create an IDEA
981: # cipher object.
982: # Parameters:
983: # (self)
984: # Returns:
985: # true - Success.
986: # false - Failure.
987: #
988: # Assumptions:
989: # 1. The ssl session setup has timeout logic built in so we don't
990: # have to worry about DOS attacks at that stage.
991: # 2. If the ssl session gets set up we are talking to a legitimate
992: # lond so again we don't have to worry about DOS attacks.
993: # All this allows us just to call
994: sub ExchangeKeysViaSSL {
995: my $self = shift;
996: my $socket = $self->{Socket};
997:
998: # Get our signed certificate, the certificate authority's
999: # certificate and our private key file. All of these
1000: # are needed to create the ssl connection.
1001:
1002: my ($SSLCACertificate,
1003: $SSLCertificate) = lonssl::CertificateFile();
1004: my $SSLKey = lonssl::KeyFile();
1005:
1006: # Promote our connection to ssl and read the key from lond.
1007:
1008: my $SSLSocket = lonssl::PromoteClientSocket($socket,
1009: $SSLCACertificate,
1010: $SSLCertificate,
1011: $SSLKey);
1012: if(defined $SSLSocket) {
1013: my $key = <$SSLSocket>;
1014: lonssl::Close($SSLSocket);
1015: if($key) {
1016: chomp($key); # \n is not part of the key.
1017: return $self->CreateCipher($key);
1018: }
1019: else {
1020: Debug(3, "Failed to read ssl key");
1021: return 0;
1022: }
1023: }
1024: else {
1025: # Failed!!
1026: Debug(3, "Failed to negotiate SSL connection!");
1027: return 0;
1028: }
1029: # should not get here
1030: return 0;
1031:
1032: }
1033:
1034:
1035:
1036: #
1037: # CompleteInsecure:
1038: # This function is called to initiate the completion of
1039: # insecure challenge response negotiation.
1040: # To do this, we copy the challenge string to the transaction
1041: # request, flip to writability and state transition to
1042: # ChallengeReceived..
1043: # All this is only possible if InsecureOk is true.
1044: # Parameters:
1045: # (self) - This object's context hash.
1046: # Return:
1047: # 0 - Ok to transition.
1048: # -1 - Not ok to transition (InsecureOk not ok).
1049: #
1050: sub CompleteInsecure {
1051: my $self = shift;
1052: if($InsecureOk) {
1053: $self->{AuthenticationMode} = "insecure";
1054: &Debug(8," Transition out of Initialized:insecure");
1055: $self->{TransactionRequest} = $self->{TransactionReply};
1056: $self->{InformWritable} = 1;
1057: $self->{InformReadable} = 0;
1058: $self->Transition("ChallengeReceived");
1059: $self->{TimeoutRemaining} = $self->{TimeoutValue};
1060: return 0;
1061:
1062:
1063: }
1064: else {
1065: &Debug(3, "Insecure key negotiation disabled!");
1066: my $socket = $self->{Socket};
1067: $socket->close;
1068: return -1;
1069: }
1070: }
1.1 foxr 1071:
1.14 foxr 1072: ###########################################################
1073: #
1074: # The following is an unashamed kludge that is here to
1075: # allow LondConnection to be used outside of the
1076: # loncapa environment (e.g. by lonManage).
1077: #
1078: # This is a textual inclusion of pieces of the
1079: # Configuration.pm module.
1080: #
1081:
1082:
1.43 raeburn 1083: my @confdirs=('/etc/httpd/conf/','/etc/apache2/');
1.14 foxr 1084:
1085: # ------------------- Subroutine read_conf: read LON-CAPA server configuration.
1086: # This subroutine reads PerlSetVar values out of specified web server
1087: # configuration files.
1088: sub read_conf
1089: {
1090: my (@conf_files)=@_;
1.43 raeburn 1091: my (%perlvar,%configdirs);
1092: foreach my $filename (@conf_files,'loncapa_apache.conf') {
1093: my $configdir = '';
1094: $configdirs{$filename} = [@confdirs];
1095: while ($configdir eq '' && @{$configdirs{$filename}} > 0) {
1096: my $testdir = shift(@{$configdirs{$filename}});
1097: if (-e $testdir.$filename) {
1098: $configdir = $testdir;
1099: }
1100: }
1101: if ($configdir eq '') {
1102: die("Couldn't find a directory containing $filename");
1103: }
1104: if($DebugLevel > 3) {
1105: print STDERR ("Going to read $configdir.$filename\n");
1106: }
1107: open(CONFIG,'<'.$configdir.$filename) or
1108: die("Can't read $configdir$filename");
1109: while (my $configline=<CONFIG>) {
1110: if ($configline =~ /^[^\#]*PerlSetVar/) {
1111: my ($unused,$varname,$varvalue)=split(/\s+/,$configline);
1.14 foxr 1112: chomp($varvalue);
1113: $perlvar{$varname}=$varvalue;
1.43 raeburn 1114: }
1115: }
1.14 foxr 1116: close(CONFIG);
1.43 raeburn 1117: }
1.21 foxr 1118: if($DebugLevel > 3) {
1.31 foxr 1119: print STDERR "Dumping perlvar:\n";
1.21 foxr 1120: foreach my $var (keys %perlvar) {
1.31 foxr 1121: print STDERR "$var = $perlvar{$var}\n";
1.21 foxr 1122: }
1123: }
1.14 foxr 1124: my $perlvarref=\%perlvar;
1.21 foxr 1125: return $perlvarref;
1126: }
1.14 foxr 1127:
1.24 foxr 1128: #
1129: # Get the version of our peer. Note that this is only well
1130: # defined if the state machine has hit the idle state at least
1131: # once (well actually if it has transitioned out of
1132: # ReadingVersionString The member data LondVersion is returned.
1133: #
1134: sub PeerVersion {
1135: my $self = shift;
1.40 albertel 1136: my ($version) = ($self->{LondVersion} =~ /Revision: 1\.(\d+)/);
1137: return $version;
1.24 foxr 1138: }
1.1 foxr 1139:
1140: 1;
1141:
1142: =pod
1.3 albertel 1143:
1.1 foxr 1144: =head1 Theory
1145:
1.3 albertel 1146: The lond object is a state machine. It lives through the following states:
1147:
1148: =item Connected:
1149:
1150: a TCP connection has been formed, but the passkey has not yet been
1151: negotiated.
1152:
1153: =item Initialized:
1154:
1155: "init" sent.
1156:
1157: =item ChallengeReceived:
1158:
1159: lond sent its challenge to us.
1160:
1161: =item ChallengeReplied:
1162:
1163: We replied to lond's challenge waiting for lond's ok.
1164:
1165: =item RequestingKey:
1166:
1167: We are requesting an encryption key.
1168:
1169: =item ReceivingKey:
1170:
1171: We are receiving an encryption key.
1172:
1173: =item Idle:
1174:
1175: Connection was negotiated but no requests are active.
1176:
1177: =item SendingRequest:
1178:
1179: A request is being sent to the peer.
1180:
1181: =item ReceivingReply:
1182:
1183: Waiting for an entire reply from the peer.
1184:
1185: =item Disconnected:
1186:
1187: For whatever reason, the connection was dropped.
1188:
1189: When we need to be writing data, we have a writable event. When we
1190: need to be reading data, a readable event established. Events
1191: dispatch through the class functions Readable and Writable, and the
1192: watcher contains a reference to the associated object to allow object
1193: context to be reached.
1.1 foxr 1194:
1195: =head2 Member data.
1196:
1.3 albertel 1197: =item Host
1198:
1199: Host socket is connected to.
1200:
1201: =item Port
1202:
1203: The port the remote lond is listening on.
1204:
1205: =item Socket
1206:
1207: Socket open on the connection.
1208:
1209: =item State
1210:
1211: The current state.
1212:
1.31 foxr 1213: =item AuthenticationMode
1214:
1215: How authentication is being done. This can be any of:
1216:
1217: o local - Authenticate via a key exchanged in a file.
1218: o ssl - Authenticate via a key exchaned through a temporary ssl tunnel.
1219: o insecure - Exchange keys in an insecure manner.
1220:
1221: insecure is only allowed if the configuration parameter loncAllowInsecure
1222: is nonzero.
1223:
1.3 albertel 1224: =item TransactionRequest
1225:
1226: The request being transmitted.
1227:
1228: =item TransactionReply
1229:
1230: The reply being received from the transaction.
1231:
1232: =item InformReadable
1233:
1234: True if we want to be called when socket is readable.
1235:
1236: =item InformWritable
1237:
1238: True if we want to be informed if the socket is writable.
1239:
1240: =item Timeoutable
1241:
1242: True if the current operation is allowed to timeout.
1243:
1244: =item TimeoutValue
1245:
1246: Number of seconds in the timeout.
1247:
1248: =item TimeoutRemaining
1249:
1250: Number of seconds left in the timeout.
1251:
1252: =item CipherKey
1253:
1254: The key that was negotiated with the peer.
1255:
1256: =item Cipher
1257:
1258: The cipher obtained via the key.
1.1 foxr 1259:
1260:
1261: =head2 The following are callback like members:
1.3 albertel 1262:
1263: =item Tick:
1264:
1265: Called in response to a timer tick. Used to managed timeouts etc.
1266:
1267: =item Readable:
1268:
1269: Called when the socket becomes readable.
1270:
1271: =item Writable:
1272:
1273: Called when the socket becomes writable.
1274:
1275: =item TimedOut:
1276:
1277: Called when a timed operation timed out.
1278:
1.1 foxr 1279:
1280: =head2 The following are operational member functions.
1.3 albertel 1281:
1282: =item InitiateTransaction:
1283:
1284: Called to initiate a new transaction
1285:
1286: =item SetStateTransitionCallback:
1287:
1288: Called to establish a function that is called whenever the object goes
1289: through a state transition. This is used by The client to manage the
1290: work flow for the object.
1291:
1292: =item SetTimeoutCallback:
1293:
1294: Set a function to be called when a transaction times out. The
1295: function will be called with the object as its sole parameter.
1296:
1297: =item Encrypt:
1298:
1299: Encrypts a block of text according to the cipher negotiated with the
1300: peer (assumes the text is a command).
1301:
1302: =item Decrypt:
1303:
1304: Decrypts a block of text according to the cipher negotiated with the
1305: peer (assumes the block was a reply.
1.5 foxr 1306:
1307: =item Shutdown:
1308:
1309: Shuts off the socket.
1.1 foxr 1310:
1311: =head2 The following are selector member functions:
1312:
1.3 albertel 1313: =item GetState:
1314:
1315: Returns the current state
1316:
1317: =item GetSocket:
1318:
1319: Gets the socekt open on the connection to lond.
1320:
1321: =item WantReadable:
1322:
1323: true if the current state requires a readable event.
1324:
1325: =item WantWritable:
1326:
1327: true if the current state requires a writable event.
1328:
1329: =item WantTimeout:
1330:
1331: true if the current state requires timeout support.
1332:
1.1 foxr 1333: =cut
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