Annotation of loncom/LondConnection.pm, revision 1.56

1.2       albertel    1: #   This module defines and implements a class that represents
                      2: #   a connection to a lond daemon.
                      3: #
1.56    ! raeburn     4: # $Id: LondConnection.pm,v 1.55 2017/10/20 20:20:21 raeburn 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: 
1.32      foxr       43: my $DebugLevel=0;
1.12      foxr       44: my %perlvar;
1.54      raeburn    45: my %secureconf;
1.56    ! raeburn    46: my %badcerts;
1.54      raeburn    47: my %hosttypes; 
1.31      foxr       48: my $InsecureOk;
1.1       foxr       49: 
1.14      foxr       50: #
1.16      foxr       51: #  Set debugging level
                     52: #
                     53: sub SetDebug {
                     54:     $DebugLevel = shift;
                     55: }
                     56: 
                     57: #
1.14      foxr       58: #   The config read is done in this way to support the read of
                     59: #   the non-default configuration file in the
                     60: #   event we are being used outside of loncapa.
                     61: #
                     62: 
                     63: my $ConfigRead = 0;
                     64: 
1.1       foxr       65: #   Read the configuration file for apache to get the perl
1.31      foxr       66: #   variables set.
1.1       foxr       67: 
1.12      foxr       68: sub ReadConfig {
1.31      foxr       69:     Debug(8, "ReadConfig called");
                     70: 
1.14      foxr       71:     my $perlvarref = read_conf('loncapa.conf');
1.12      foxr       72:     %perlvar    = %{$perlvarref};
1.17      foxr       73:     $ConfigRead = 1;
1.54      raeburn    74: 
1.31      foxr       75:     $InsecureOk = $perlvar{loncAllowInsecure};
1.54      raeburn    76: 
                     77:     unless (lonssl::Read_Connect_Config(\%secureconf,\%perlvar) eq 'ok') {
                     78:         Debug(1,"Failed to retrieve secureconf hash.\n");
                     79:     }
                     80:     unless (lonssl::Read_Host_Types(\%hosttypes,\%perlvar) eq 'ok') {
                     81:         Debug(1,"Failed to retrieve hosttypes hash.\n");
                     82:     }
1.56    ! raeburn    83:     undef(%badcerts);
1.54      raeburn    84: }
                     85: 
                     86: sub ResetReadConfig {
                     87:     $ConfigRead = 0;
1.15      foxr       88: }
1.1       foxr       89: 
                     90: sub Debug {
1.30      foxr       91: 
                     92:     my ($level, $message) = @_;
                     93: 
1.1       foxr       94:     if ($level < $DebugLevel) {
1.31      foxr       95: 	print STDERR ($message."\n");
1.1       foxr       96:     }
                     97: }
1.3       albertel   98: 
                     99: =pod
                    100: 
                    101: =head2 Dump
                    102: 
1.12      foxr      103: Dump the internal state of the object: For debugging purposes, to stderr.
1.3       albertel  104: 
1.1       foxr      105: =cut
                    106: 
                    107: sub Dump {
                    108:     my $self   = shift;
1.32      foxr      109:     my $level  = shift;
1.35      foxr      110:     my $now    = time;
                    111:     my $local  = localtime($now);
1.32      foxr      112:     
1.37      albertel  113:     if ($level >= $DebugLevel) {
1.32      foxr      114: 	return;
                    115:     }
                    116: 
1.35      foxr      117:     
1.10      foxr      118:     my $key;
                    119:     my $value;
1.35      foxr      120:     print STDERR "[ $local ] Dumping LondConnectionObject:\n";
1.37      albertel  121:     print STDERR join(':',caller(1))."\n";
1.1       foxr      122:     while(($key, $value) = each %$self) {
1.22      foxr      123: 	print STDERR "$key -> $value\n";
1.1       foxr      124:     }
1.23      foxr      125:     print STDERR "-------------------------------\n";
1.1       foxr      126: }
                    127: 
                    128: =pod
1.3       albertel  129: 
                    130: Local function to do a state transition.  If the state transition
                    131: callback is defined it is called with two parameters: the self and the
                    132: old state.
                    133: 
1.1       foxr      134: =cut
1.3       albertel  135: 
1.1       foxr      136: sub Transition {
1.30      foxr      137: 
                    138:     my ($self, $newstate) = @_;
                    139: 
1.1       foxr      140:     my $oldstate = $self->{State};
                    141:     $self->{State} = $newstate;
                    142:     $self->{TimeoutRemaining} = $self->{TimeoutValue};
                    143:     if($self->{TransitionCallback}) {
                    144: 	($self->{TransitionCallback})->($self, $oldstate); 
                    145:     }
                    146: }
                    147: 
1.3       albertel  148: 
1.14      foxr      149: 
1.1       foxr      150: =pod
1.3       albertel  151: 
                    152: =head2 new
                    153: 
                    154: Construct a new lond connection.
                    155: 
                    156: Parameters (besides the class name) include:
                    157: 
                    158: =item hostname
                    159: 
                    160: host the remote lond is on. This host is a host in the hosts.tab file
                    161: 
                    162: =item port
                    163: 
                    164:  port number the remote lond is listening on.
                    165: 
1.1       foxr      166: =cut
1.3       albertel  167: 
1.1       foxr      168: sub new {
1.44      albertel  169:     my ($class, $DnsName, $Port, $lonid) = @_;
1.14      foxr      170: 
                    171:     if (!$ConfigRead) {
                    172: 	ReadConfig();
                    173: 	$ConfigRead = 1;
                    174:     }
1.45      albertel  175:     &Debug(4,$class."::new( ".$DnsName.",".$Port.",".$lonid.")\n");
1.1       foxr      176: 
1.56    ! raeburn   177:     my ($conntype,$gotconninfo,$allowinsecure);
        !           178:     if ((ref($secureconf{'connto'}) eq 'HASH') &&
        !           179:         (exists($hosttypes{$lonid}))) {
        !           180:         $conntype = $secureconf{'connto'}{$hosttypes{$lonid}};
        !           181:         if ($conntype ne '') {
        !           182:             if ($conntype ne 'req') {
        !           183:                 $allowinsecure = 1;
        !           184:             }
        !           185:             $gotconninfo = 1;
        !           186:         }
        !           187:     }
        !           188:     unless ($gotconninfo) {
        !           189:         $allowinsecure = $InsecureOk;
        !           190:     }
        !           191: 
1.1       foxr      192:     # The host must map to an entry in the hosts table:
                    193:     #  We connect to the dns host that corresponds to that
                    194:     #  system and use the hostname for the encryption key 
                    195:     #  negotion.  In the objec these become the Host and
                    196:     #  LoncapaHim fields of the object respectively.
                    197:     #
1.36      albertel  198:     # if it is me use loopback for connection
1.44      albertel  199:     if ($DnsName eq &main::my_hostname()) { $DnsName="127.0.0.1"; }
                    200:     Debug(9, "Connecting to $DnsName");
1.1       foxr      201:     # Now create the object...
                    202:     my $self     = { Host               => $DnsName,
1.44      albertel  203:                      LoncapaHim         => $lonid,
1.24      foxr      204:                      Port               => $Port,
                    205:                      State              => "Initialized",
1.31      foxr      206: 		     AuthenticationMode => "",
1.56    ! raeburn   207: 		     InsecureOK         => $allowinsecure,                     
1.24      foxr      208:                      TransactionRequest => "",
                    209:                      TransactionReply   => "",
1.39      albertel  210:                      NextRequest        => "",
1.24      foxr      211:                      InformReadable     => 0,
                    212:                      InformWritable     => 0,
                    213:                      TimeoutCallback    => undef,
                    214:                      TransitionCallback => undef,
                    215:                      Timeoutable        => 0,
1.49      raeburn   216:                      TimeoutValue       => 30,
1.24      foxr      217:                      TimeoutRemaining   => 0,
1.31      foxr      218: 		     LocalKeyFile       => "",
1.24      foxr      219:                      CipherKey          => "",
                    220:                      LondVersion        => "Unknown",
1.52      foxr      221:                      Cipher             => undef,
                    222: 		     ClientData         => undef};
1.1       foxr      223:     bless($self, $class);
                    224:     unless ($self->{Socket} = IO::Socket::INET->new(PeerHost => $self->{Host},
1.27      foxr      225: 					       PeerPort => $self->{Port},
                    226: 					       Type     => SOCK_STREAM,
                    227: 					       Proto    => "tcp",
                    228: 					       Timeout  => 3)) {
1.36      albertel  229: 	Debug(8, "Error? \n$@ \n$!");
1.1       foxr      230: 	return undef;		# Inidicates the socket could not be made.
                    231:     }
1.31      foxr      232:     my $socket = $self->{Socket}; # For local use only.
1.51      foxr      233:     $socket->sockopt(SO_KEEPALIVE, 1); # Turn on keepalive probes when idle.
1.33      foxr      234:     #  If we are local, we'll first try local auth mode, otherwise, we'll try
                    235:     #  the ssl auth mode:
1.31      foxr      236: 
                    237:     my $key;
                    238:     my $keyfile;
1.36      albertel  239:     if ($DnsName eq '127.0.0.1') {
1.31      foxr      240: 	$self->{AuthenticationMode} = "local";
                    241: 	($key, $keyfile)         = lonlocal::CreateKeyFile();
                    242: 	Debug(8, "Local key: $key, stored in $keyfile");
                    243: 	   
                    244: 	#  If I can't make the key file fall back to insecure if 
                    245: 	#  allowed...else give up right away.
                    246: 
                    247: 	if(!(defined $key) || !(defined $keyfile)) {
1.54      raeburn   248:             my $canconnect = 0;
                    249:             if (ref($secureconf{'connto'}) eq 'HASH') {
                    250:                 unless ($secureconf{'connto'}->{'dom'} eq 'req') {
                    251:                     $canconnect = 1;
                    252:                 }
                    253:             } else {
                    254:                 $canconnect = $InsecureOk;
                    255:             }
                    256: 	    if ($canconnect) {
1.31      foxr      257: 		$self->{AuthenticationMode} = "insecure";
                    258: 		$self->{TransactionRequest} = "init\n";
                    259: 	    } 
                    260: 	    else {
                    261: 		$socket->close;
                    262: 		return undef;
                    263: 	    }
                    264: 	}
                    265: 	$self->{TransactionRequest} = "init:local:$keyfile\n";
                    266: 	Debug(9, "Init string is init:local:$keyfile");
                    267: 	if(!$self->CreateCipher($key)) { # Nothing's going our way...
                    268: 	    $socket->close;
                    269: 	    return undef;
                    270: 	}
                    271: 
1.42      albertel  272:     } else {
1.33      foxr      273: 	#  Remote peer:  I'd like to do ssl, but if my host key or certificates
                    274: 	#  are not all installed, my only choice is insecure, if that's 
                    275: 	#  allowed:
                    276: 
                    277: 	my ($ca, $cert) = lonssl::CertificateFile;
                    278: 	my $sslkeyfile  = lonssl::KeyFile;
                    279: 
1.56    ! raeburn   280: 	if (($conntype ne 'no') && (defined($ca)) && (defined($cert)) && (defined($sslkeyfile)) &&
        !           281:             (!exists($badcerts{$self->{LoncapaHim}}))) {
1.33      foxr      282: 	    $self->{AuthenticationMode} = "ssl";
1.47      raeburn   283: 	    $self->{TransactionRequest} = "init:ssl:$perlvar{'lonVersion'}\n";
1.56    ! raeburn   284: 	} elsif ($self->{InsecureOK}) {
1.54      raeburn   285: 	    # Allowed to do insecure:
                    286: 	    $self->{AuthenticationMode} = "insecure";
                    287: 	    $self->{TransactionRequest} = "init::$perlvar{'lonVersion'}\n";
1.33      foxr      288: 	} else {
1.54      raeburn   289: 	    # Not allowed to do insecure...
                    290: 	    $socket->close;
                    291: 	    return undef;
1.33      foxr      292: 	}
1.31      foxr      293:     }
                    294: 
1.1       foxr      295:     #
                    296:     # We're connected.  Set the state, and the events we'll accept:
                    297:     #
                    298:     $self->Transition("Connected");
                    299:     $self->{InformWritable}     = 1;    # When  socket is writable we send init
1.9       foxr      300:     $self->{Timeoutable}        = 1;    # Timeout allowed during startup negotiation. 
1.31      foxr      301: 
1.1       foxr      302:     
                    303:     #
                    304:     # Set socket to nonblocking I/O.
                    305:     #
1.31      foxr      306:     my $flags    = fcntl($socket, F_GETFL,0);
                    307:     if(!$flags) {
1.1       foxr      308: 	$socket->close;
                    309: 	return undef;
                    310:     }
1.31      foxr      311:     if(!fcntl($socket, F_SETFL, $flags | O_NONBLOCK)) {
1.1       foxr      312: 	$socket->close;
                    313: 	return undef;
                    314:     }
                    315: 
                    316:     # return the object :
                    317: 
1.31      foxr      318:     Debug(9, "Initial object state: ");
1.32      foxr      319:     $self->Dump(9);
1.31      foxr      320: 
1.1       foxr      321:     return $self;
                    322: }
1.3       albertel  323: 
1.1       foxr      324: =pod
1.3       albertel  325: 
                    326: =head2 Readable
                    327: 
                    328: This member should be called when the Socket becomes readable.  Until
                    329: the read completes, action is state independet. Data are accepted into
                    330: the TransactionReply until a newline character is received.  At that
                    331: time actionis state dependent:
                    332: 
                    333: =item Connected
                    334: 
                    335: in this case we received challenge, the state changes to
                    336: ChallengeReceived, and we initiate a send with the challenge response.
                    337: 
                    338: =item ReceivingReply
                    339: 
                    340: In this case a reply has been received for a transaction, the state
                    341: goes to Idle and we disable write and read notification.
                    342: 
                    343: =item ChallengeReeived
                    344: 
                    345: we just got what should be an ok\n and the connection can now handle
                    346: transactions.
1.1       foxr      347: 
                    348: =cut
1.3       albertel  349: 
1.1       foxr      350: sub Readable {
                    351:     my $self    = shift;
                    352:     my $socket  = $self->{Socket};
                    353:     my $data    = '';
1.27      foxr      354:     my $rv;
1.31      foxr      355:     my $ConnectionMode = $self->{AuthenticationMode};
                    356: 
1.27      foxr      357:     if ($socket) {
                    358: 	eval {
                    359: 	    $rv = $socket->recv($data, POSIX::BUFSIZ, 0);
                    360: 	}
                    361:     } else {
                    362: 	$self->Transition("Disconnected");
                    363: 	return -1;
                    364:     }
1.1       foxr      365:     my $errno   = $! + 0;	             # Force numeric context.
                    366: 
1.8       foxr      367:     unless (defined($rv) && length $data) {# Read failed,
1.1       foxr      368: 	if(($errno == POSIX::EWOULDBLOCK)   ||
                    369: 	   ($errno == POSIX::EAGAIN)        ||
1.8       foxr      370: 	   ($errno == POSIX::EINTR)) {
1.1       foxr      371: 	    return 0;
                    372: 	}
                    373: 
                    374: 	# Connection likely lost.
                    375: 	&Debug(4, "Connection lost");
                    376: 	$self->{TransactionRequest} = '';
                    377: 	$socket->close();
                    378: 	$self->Transition("Disconnected");
                    379: 	return -1;
                    380:     }
1.53      foxr      381:     # If we actually got data, reset the timeout.
                    382: 
                    383:     if (length $data) {
                    384: 	$self->{TimeoutRemaining}   = $self->{TimeoutValue}; # getting data resets the timeout period.
                    385:     }
1.1       foxr      386:     #  Append the data to the buffer.  And figure out if the read is done:
                    387: 
                    388:     &Debug(9,"Received from host: ".$data);
                    389:     $self->{TransactionReply} .= $data;
1.29      albertel  390:     if($self->{TransactionReply} =~ m/\n$/) {
1.1       foxr      391: 	&Debug(8,"Readable End of line detected");
1.31      foxr      392: 	
                    393: 
1.1       foxr      394: 	if ($self->{State}  eq "Initialized") { # We received the challenge:
1.31      foxr      395: 	    #   Our init was replied to. What happens next depends both on
                    396: 	    #  the actual init we sent (AuthenticationMode member data)
                    397: 	    #  and the response:
                    398: 	    #     AuthenticationMode == local:
                    399: 	    #       Response ok:   The key has been exchanged and
                    400: 	    #                      the key file destroyed. We can jump
                    401: 	    #                      into setting the host and requesting the
                    402: 	    #                      Later we'll also bypass key exchange.
                    403: 	    #       Response digits: 
                    404: 	    #                      Old style lond. Delete the keyfile.
                    405: 	    #                      If allowed fall back to insecure mode.
                    406: 	    #                      else close connection and fail.
                    407: 	    #       Response other:
                    408: 	    #                      Failed local auth 
                    409: 	    #                      Close connection and fail.
                    410: 	    #
                    411: 	    #    AuthenticationMode == ssl:
                    412: 	    #        Response ok:ssl
                    413: 	    #        Response digits:
                    414: 	    #        Response other:
                    415: 	    #    Authentication mode == insecure
                    416: 	    #        Response digits
                    417: 	    #        Response other:
                    418: 	    
                    419: 	    my $Response = $self->{TransactionReply};
                    420: 	    if($ConnectionMode eq "local") {
                    421: 		if($Response =~ /^ok:local/) { #  Good local auth.
                    422: 		    $self->ToVersionRequest();
                    423: 		    return 0;
                    424: 		}
                    425: 		elsif ($Response =~/^[0-9]+/) {	# Old style lond.
                    426: 		    return $self->CompleteInsecure();
                    427: 
                    428: 		}
                    429: 		else {		                # Complete flop
                    430: 		    &Debug(3, "init:local : unrecognized reply");
                    431: 		    $self->Transition("Disconnected");
                    432: 		    $socket->close;
                    433: 		    return -1;
                    434: 		}
                    435: 	    }
                    436: 	    elsif ($ConnectionMode eq "ssl") {
                    437: 		if($Response =~ /^ok:ssl/) {     # Good ssl...
1.56    ! raeburn   438: 		    my $sslresult = $self->ExchangeKeysViaSSL();
        !           439:                     if ($sslresult == 1) { # Success skip to vsn stuff
1.31      foxr      440: 			# Need to reset to non blocking:
                    441: 
                    442: 			my $flags = fcntl($socket, F_GETFL, 0);
                    443: 			fcntl($socket, F_SETFL, $flags | O_NONBLOCK);
                    444: 			$self->ToVersionRequest();
                    445: 			return 0;
                    446: 		    }
                    447: 		    else {	         # Failed in ssl exchange.
1.56    ! raeburn   448: 		        if (($sslresult == -1) && ($self->{InsecureOK})) {
        !           449: 			    $badcerts{$self->{LoncapaHim}} = 1;
        !           450: 			}
1.31      foxr      451: 			&Debug(3,"init:ssl failed key negotiation!");
                    452: 			$self->Transition("Disconnected");
                    453: 			$socket->close;
                    454: 			return -1;
                    455: 		    }
                    456: 		} 
                    457: 		elsif ($Response =~ /^[0-9]+/) { # Old style lond.
                    458: 		    return $self->CompleteInsecure();
                    459: 		}
                    460: 		else {		                 # Complete flop
                    461: 		}
                    462: 	    }
                    463: 	    elsif ($ConnectionMode eq "insecure") {
                    464: 		if($self->{TransactionReply} eq "refused\n") {	# Remote doesn't have
                    465: 		    
                    466: 		    $self->Transition("Disconnected"); # in host tables.
                    467: 		    $socket->close();
                    468: 		    return -1;
                    469: 
                    470: 		}
                    471: 		return $self->CompleteInsecure();
                    472: 	    }
                    473: 	    else {
                    474: 		&Debug(1,"Authentication mode incorrect");
                    475: 		die "BUG!!! LondConnection::Readable invalid authmode";
1.1       foxr      476: 	    }
1.27      foxr      477: 
1.31      foxr      478: 
1.28      albertel  479: 	}  elsif ($self->{State} eq "ChallengeReplied") {
                    480: 	    if($self->{TransactionReply} ne "ok\n") {
                    481: 		$self->Transition("Disconnected");
                    482: 		$socket->close();
                    483: 		return -1;
                    484: 	    }
1.31      foxr      485: 	    $self->ToVersionRequest();
1.28      albertel  486: 	    return 0;
1.31      foxr      487: 
1.28      albertel  488: 	} elsif ($self->{State} eq "ReadingVersionString") {
1.38      albertel  489: 	    chomp($self->{TransactionReply});
                    490: 	    $self->{LondVersion}       = $self->{TransactionReply};
1.28      albertel  491: 	    $self->Transition("SetHost");
                    492: 	    $self->{InformReadable}    = 0;
                    493: 	    $self->{InformWritable}    = 1;
                    494: 	    my $peer = $self->{LoncapaHim};
                    495: 	    $self->{TransactionRequest}= "sethost:$peer\n";
                    496: 	    return 0;
1.24      foxr      497: 	} elsif ($self->{State} eq "HostSet") { # should be ok.
1.28      albertel  498: 	    if($self->{TransactionReply} ne "ok\n") {
                    499: 		$self->Transition("Disconnected");
                    500: 		$socket->close();
                    501: 		return -1;
                    502: 	    }
1.31      foxr      503: 	    #  If the auth mode is insecure we must still
                    504: 	    #  exchange session keys. Otherwise,
                    505: 	    #  we can just transition to idle.
                    506: 
                    507: 	    if($ConnectionMode eq "insecure") {
                    508: 		$self->Transition("RequestingKey");
                    509: 		$self->{InformReadable}  = 0;
                    510: 		$self->{InformWritable}  = 1;
                    511: 		$self->{TransactionRequest} = "ekey\n";
                    512: 		return 0;
                    513: 	    }
                    514: 	    else {
                    515: 		$self->ToIdle();
                    516: 		return 0;
                    517: 	    }
1.1       foxr      518: 	} elsif ($self->{State}  eq "ReceivingKey") {
                    519: 	    my $buildkey = $self->{TransactionReply};
                    520: 	    my $key = $self->{LoncapaHim}.$perlvar{'lonHostID'};
                    521: 	    $key=~tr/a-z/A-Z/;
                    522: 	    $key=~tr/G-P/0-9/;
                    523: 	    $key=~tr/Q-Z/0-9/;
1.31      foxr      524: 	    $key =$key.$buildkey.$key.$buildkey.$key.$buildkey;
                    525: 	    $key               = substr($key,0,32);
                    526: 	    if(!$self->CreateCipher($key)) {
1.1       foxr      527: 		$self->Transition("Disconnected");
                    528: 		$socket->close();
                    529: 		return -1;
                    530: 	    } else {
1.31      foxr      531: 		$self->ToIdle();
1.1       foxr      532: 		return 0;
                    533: 	    }
                    534: 	} elsif ($self->{State}  eq "ReceivingReply") {
                    535: 
                    536: 	    # If the data are encrypted, decrypt first.
                    537: 
                    538: 	    my $answer = $self->{TransactionReply};
                    539: 	    if($answer =~ /^enc\:/) {
                    540: 		$answer = $self->Decrypt($answer);
1.34      foxr      541: 		$self->{TransactionReply} = "$answer\n";
1.1       foxr      542: 	    }
1.39      albertel  543: 	    # if we have a NextRequest do it immeadiately
                    544: 	    if ($self->{NextRequest}) {
                    545: 		$self->{TransactionRequest} = $self->{NextRequest};
                    546: 		undef( $self->{NextRequest} );
                    547: 		$self->{TransactionReply}   = "";
                    548: 		$self->{InformWritable}     = 1;
                    549: 		$self->{InformReadable}     = 0;
                    550: 		$self->{Timeoutable}        = 1;
                    551: 		$self->Transition("SendingRequest");
                    552: 		return 0;
                    553: 	    } else {
1.1       foxr      554: 	    # finish the transaction
                    555: 
1.39      albertel  556: 		$self->ToIdle();
                    557: 		return 0;
                    558: 	    }
1.1       foxr      559: 	} elsif ($self->{State} eq "Disconnected") { # No connection.
                    560: 	    return -1;
                    561: 	} else {			# Internal error: Invalid state.
                    562: 	    $self->Transition("Disconnected");
                    563: 	    $socket->close();
                    564: 	    return -1;
                    565: 	}
                    566:     }
                    567: 
                    568:     return 0;
1.27      foxr      569:     
1.1       foxr      570: }
                    571: 
                    572: 
                    573: =pod
1.3       albertel  574: 
                    575: This member should be called when the Socket becomes writable.
                    576: 
                    577: The action is state independent. An attempt is made to drain the
                    578: contents of the TransactionRequest member.  Once this is drained, we
                    579: mark the object as waiting for readability.
1.1       foxr      580: 
                    581: Returns  0 if successful, or -1 if not.
1.3       albertel  582: 
1.1       foxr      583: =cut
                    584: sub Writable {
                    585:     my $self     = shift;		# Get reference to the object.
                    586:     my $socket   = $self->{Socket};
1.26      albertel  587:     my $nwritten;
                    588:     if ($socket) {
                    589: 	eval {
                    590: 	    $nwritten = $socket->send($self->{TransactionRequest}, 0);
                    591: 	}
1.27      foxr      592:     } else {
                    593: 	# For whatever reason, there's no longer a socket left.
                    594: 
                    595: 
                    596: 	$self->Transition("Disconnected");
                    597: 	return -1;
1.26      albertel  598:     }
1.1       foxr      599:     my $errno    = $! + 0;
                    600:     unless (defined $nwritten) {
                    601: 	if($errno != POSIX::EINTR) {
                    602: 	    $self->Transition("Disconnected");
                    603: 	    return -1;
                    604: 	}
                    605:       
                    606:     }
1.10      foxr      607:     if (($nwritten >= 0)                        ||
1.1       foxr      608:         ($errno == POSIX::EWOULDBLOCK)    ||
                    609: 	($errno == POSIX::EAGAIN)         ||
                    610: 	($errno == POSIX::EINTR)          ||
                    611: 	($errno ==  0)) {
1.50      foxr      612: 	$self->{TimeoutRemaining} = $self->{TimeoutValue};
1.1       foxr      613: 	substr($self->{TransactionRequest}, 0, $nwritten) = ""; # rmv written part
1.50      foxr      614: 	if(length $self->{TransactionRequest} == 0) {
                    615: 	    $self->{InformWritable} = 0;
                    616: 	    $self->{InformReadable} = 1;
                    617: 	    $self->{TransactionReply} = '';
                    618: 	    #
                    619: 	    # Figure out the next state:
                    620: 	    #
                    621: 	    if($self->{State} eq "Connected") {
                    622: 		$self->Transition("Initialized");
                    623: 	    } elsif($self->{State} eq "ChallengeReceived") {
                    624: 		$self->Transition("ChallengeReplied");
                    625: 	    } elsif($self->{State} eq "RequestingVersion") {
                    626: 		$self->Transition("ReadingVersionString");
                    627: 	    } elsif ($self->{State} eq "SetHost") {
                    628: 		$self->Transition("HostSet");
                    629: 	    } elsif($self->{State} eq "RequestingKey") {
                    630: 		$self->Transition("ReceivingKey");
1.24      foxr      631: #            $self->{InformWritable} = 0;
                    632: #            $self->{InformReadable} = 1;
                    633: #            $self->{TransactionReply} = '';
1.50      foxr      634: 	    } elsif ($self->{State} eq "SendingRequest") {
                    635: 		$self->Transition("ReceivingReply");
                    636: 		$self->{TimeoutRemaining} = $self->{TimeoutValue};
                    637: 	    } elsif ($self->{State} eq "Disconnected") {
                    638: 		return -1;
                    639: 	    }
                    640: 	    return 0;
                    641: 	}
                    642:     } else {			# The write failed (e.g. partner disconnected).
                    643: 	$self->Transition("Disconnected");
                    644: 	$socket->close();
                    645: 	return -1;
                    646:     }
                    647:     
1.1       foxr      648: }
                    649: =pod
1.3       albertel  650: 
                    651: =head2 Tick
                    652: 
1.1       foxr      653:    Tick is called every time unit by the event framework.  It
1.3       albertel  654: 
                    655: =item 1 decrements the remaining timeout.
                    656: 
                    657: =item 2 If the timeout is zero, calls TimedOut indicating that the current operation timed out.
1.1       foxr      658: 
                    659: =cut
                    660:     
                    661: sub Tick {
                    662:     my $self = shift;
                    663:     $self->{TimeoutRemaining}--;
                    664:     if ($self->{TimeoutRemaining} < 0) {
                    665: 	$self->TimedOut();
                    666:     }
                    667: }
1.3       albertel  668: 
1.1       foxr      669: =pod
                    670: 
1.3       albertel  671: =head2 TimedOut
                    672: 
                    673: called on a timeout.  If the timeout callback is defined, it is called
                    674: with $self as its parameters.
                    675: 
                    676: =cut
                    677: 
1.1       foxr      678: sub TimedOut  {
                    679: 
                    680:     my $self = shift;
                    681:     if($self->{TimeoutCallback}) {
                    682: 	my $callback = $self->{TimeoutCallback};
                    683: 	my @args = ( $self);
                    684: 	&$callback(@args);
                    685:     }
                    686: }
1.3       albertel  687: 
1.1       foxr      688: =pod
1.3       albertel  689: 
                    690: =head2 InitiateTransaction
                    691: 
                    692: Called to initiate a transaction.  A transaction can only be initiated
                    693: when the object is idle... otherwise an error is returned.  A
                    694: transaction consists of a request to the server that will have a
                    695: reply.  This member sets the request data in the TransactionRequest
                    696: member, makes the state SendingRequest and sets the data to allow a
                    697: timout, and to request writability notification.
                    698: 
1.1       foxr      699: =cut
1.3       albertel  700: 
1.1       foxr      701: sub InitiateTransaction {
1.30      foxr      702: 
                    703:     my ($self, $data) = @_;
1.1       foxr      704: 
1.4       foxr      705:     Debug(1, "initiating transaction: ".$data);
1.1       foxr      706:     if($self->{State} ne "Idle") {
1.4       foxr      707: 	Debug(0," .. but not idle here\n");
1.1       foxr      708: 	return -1;		# Error indicator.
                    709:     }
                    710:     # if the transaction is to be encrypted encrypt the data:
1.39      albertel  711:     (my $sethost, my $server,$data)=split(/:/,$data,3);
1.1       foxr      712: 
                    713:     if($data =~ /^encrypt\:/) {
                    714: 	$data = $self->Encrypt($data);
                    715:     }
                    716: 
                    717:     # Setup the trasaction
1.39      albertel  718:     # currently no version of lond supports inlining the sethost
1.40      albertel  719:     if ($self->PeerVersion() <= 321) {
1.39      albertel  720: 	if ($server ne $self->{LoncapaHim}) {
                    721: 	    $self->{NextRequest}        = $data;
                    722: 	    $self->{TransactionRequest} = "$sethost:$server\n";
                    723: 	    $self->{LoncapaHim}         = $server;
                    724: 	} else {
                    725: 	    $self->{TransactionRequest}        = $data;
                    726: 	}
                    727:     } else {
1.40      albertel  728: 	$self->{LoncapaHim}         = $server;
1.39      albertel  729: 	$self->{TransactionRequest} = "$sethost:$server:$data";
                    730:     }
1.1       foxr      731:     $self->{TransactionReply}   = "";
                    732:     $self->{InformWritable}     = 1;
                    733:     $self->{InformReadable}     = 0;
                    734:     $self->{Timeoutable}        = 1;
                    735:     $self->{TimeoutRemaining}   = $self->{TimeoutValue};
                    736:     $self->Transition("SendingRequest");
                    737: }
                    738: 
                    739: 
                    740: =pod
1.3       albertel  741: 
                    742: =head2 SetStateTransitionCallback
                    743: 
                    744: Sets a callback for state transitions.  Returns a reference to any
                    745: prior established callback, or undef if there was none:
                    746: 
1.1       foxr      747: =cut
1.3       albertel  748: 
1.1       foxr      749: sub SetStateTransitionCallback {
                    750:     my $self        = shift;
                    751:     my $oldCallback = $self->{TransitionCallback};
                    752:     $self->{TransitionCallback} = shift;
                    753:     return $oldCallback;
                    754: }
1.3       albertel  755: 
1.1       foxr      756: =pod
1.3       albertel  757: 
                    758: =head2 SetTimeoutCallback
                    759: 
                    760: Sets the timeout callback.  Returns a reference to any prior
                    761: established callback or undef if there was none.
                    762: 
1.1       foxr      763: =cut
1.3       albertel  764: 
1.1       foxr      765: sub SetTimeoutCallback {
1.30      foxr      766: 
                    767:     my ($self, $callback) = @_;
                    768: 
1.1       foxr      769:     my $oldCallback          = $self->{TimeoutCallback};
                    770:     $self->{TimeoutCallback} = $callback;
                    771:     return $oldCallback;
                    772: }
                    773: 
                    774: =pod
1.3       albertel  775: 
1.5       foxr      776: =head2 Shutdown:
                    777: 
                    778: Shuts down the socket.
                    779: 
                    780: =cut
                    781: 
                    782: sub Shutdown {
                    783:     my $self = shift;
                    784:     my $socket = $self->GetSocket();
1.20      albertel  785:     Debug(5,"socket is -$socket-");
                    786:     if ($socket) {
                    787: 	# Ask lond to exit too.  Non blocking so
                    788: 	# there is no cost for failure.
                    789: 	eval {
                    790: 	    $socket->send("exit\n", 0);
                    791: 	    $socket->shutdown(2);
                    792: 	}
                    793:     }
1.50      foxr      794:     $self->{Timeoutable}   = 0;	# Shutdown sockets can't timeout.
1.5       foxr      795: }
                    796: 
                    797: =pod
                    798: 
1.3       albertel  799: =head2 GetState
                    800: 
                    801: selector for the object state.
                    802: 
1.1       foxr      803: =cut
1.3       albertel  804: 
1.1       foxr      805: sub GetState {
                    806:     my $self = shift;
                    807:     return $self->{State};
                    808: }
1.3       albertel  809: 
1.1       foxr      810: =pod
1.3       albertel  811: 
                    812: =head2 GetSocket
                    813: 
                    814: selector for the object socket.
                    815: 
1.1       foxr      816: =cut
1.3       albertel  817: 
1.1       foxr      818: sub GetSocket {
                    819:     my $self  = shift;
                    820:     return $self->{Socket};
                    821: }
1.3       albertel  822: 
1.5       foxr      823: 
1.1       foxr      824: =pod
1.3       albertel  825: 
                    826: =head2 WantReadable
                    827: 
                    828: Return the state of the flag that indicates the object wants to be
                    829: called when readable.
                    830: 
1.1       foxr      831: =cut
1.3       albertel  832: 
1.1       foxr      833: sub WantReadable {
                    834:     my   $self = shift;
                    835: 
                    836:     return $self->{InformReadable};
                    837: }
1.3       albertel  838: 
1.1       foxr      839: =pod
1.3       albertel  840: 
                    841: =head2 WantWritable
                    842: 
                    843: Return the state of the flag that indicates the object wants write
                    844: notification.
                    845: 
1.1       foxr      846: =cut
1.3       albertel  847: 
1.1       foxr      848: sub WantWritable {
                    849:     my $self = shift;
                    850:     return $self->{InformWritable};
                    851: }
1.3       albertel  852: 
1.1       foxr      853: =pod
1.3       albertel  854: 
                    855: =head2 WantTimeout
                    856: 
                    857: return the state of the flag that indicates the object wants to be
                    858: informed of timeouts.
                    859: 
1.1       foxr      860: =cut
1.3       albertel  861: 
1.1       foxr      862: sub WantTimeout {
                    863:     my $self = shift;
                    864:     return $self->{Timeoutable};
                    865: }
                    866: 
                    867: =pod
1.3       albertel  868: 
                    869: =head2 GetReply
                    870: 
                    871: Returns the reply from the last transaction.
                    872: 
1.1       foxr      873: =cut
1.3       albertel  874: 
1.1       foxr      875: sub GetReply {
                    876:     my $self = shift;
                    877:     return $self->{TransactionReply};
                    878: }
                    879: 
                    880: =pod
1.3       albertel  881: 
                    882: =head2 Encrypt
                    883: 
                    884: Returns the encrypted version of the command string.
                    885: 
                    886: The command input string is of the form:
                    887: 
1.1       foxr      888:   encrypt:command
1.3       albertel  889: 
                    890: The output string can be directly sent to lond as it is of the form:
                    891: 
1.1       foxr      892:   enc:length:<encodedrequest>
1.3       albertel  893: 
1.1       foxr      894: =cut
1.3       albertel  895: 
1.1       foxr      896: sub Encrypt {
1.30      foxr      897:     
                    898:     my ($self, $request) = @_;
1.1       foxr      899: 
                    900:    
                    901:     # Split the encrypt: off the request and figure out it's length.
                    902:     # the cipher works in blocks of 8 bytes.
                    903: 
                    904:     my $cmd = $request;
                    905:     $cmd    =~ s/^encrypt\://;	# strip off encrypt:
                    906:     chomp($cmd);		# strip off trailing \n
                    907:     my     $length=length($cmd);	# Get the string length.
                    908:     $cmd .= "         ";	# Pad with blanks so we can fill out a block.
                    909: 
                    910:     # encrypt the request in 8 byte chunks to create the encrypted
                    911:     # output request.
                    912: 
                    913:     my $Encoded = '';
                    914:     for(my $index = 0; $index <= $length; $index += 8) {
                    915: 	$Encoded .= 
                    916: 	    unpack("H16", 
                    917: 		   $self->{Cipher}->encrypt(substr($cmd, 
                    918: 						   $index, 8)));
                    919:     }
                    920: 
                    921:     # Build up the answer as enc:length:$encrequest.
                    922: 
                    923:     $request = "enc:$length:$Encoded\n";
                    924:     return $request;
                    925:     
                    926:     
                    927: }
1.3       albertel  928: 
                    929: =pod
                    930: 
                    931: =head2 Decrypt
                    932: 
                    933: Decrypt a response from the server.  The response is in the form:
                    934: 
                    935:  enc:<length>:<encrypted data>
                    936: 
1.1       foxr      937: =cut
1.3       albertel  938: 
1.1       foxr      939: sub Decrypt {
1.30      foxr      940: 
                    941:     my ($self, $encrypted) = @_;
1.1       foxr      942: 
                    943:     #  Bust up the response into length, and encryptedstring:
                    944: 
                    945:     my ($enc, $length, $EncryptedString) = split(/:/,$encrypted);
                    946:     chomp($EncryptedString);
                    947: 
                    948:     # Decode the data in 8 byte blocks.  The string is encoded
                    949:     # as hex digits so there are two characters per byte:
                    950: 
1.10      foxr      951:     my $decrypted = "";
1.1       foxr      952:     for(my $index = 0; $index < length($EncryptedString);
                    953: 	$index += 16) {
                    954: 	$decrypted .= $self->{Cipher}->decrypt(
                    955: 				    pack("H16",
                    956: 					 substr($EncryptedString,
                    957: 						$index, 
                    958: 						16)));
                    959:     }
                    960:     #  the answer may have trailing pads to fill out a block.
                    961:     #  $length tells us the actual length of the decrypted string:
                    962: 
                    963:     $decrypted = substr($decrypted, 0, $length);
1.34      foxr      964:     Debug(9, "Decrypted $EncryptedString to $decrypted");
1.1       foxr      965: 
                    966:     return $decrypted;
                    967: 
                    968: }
1.31      foxr      969: # ToIdle
                    970: #     Called to transition to idle... done enough it's worth subbing
                    971: #     off to ensure it's always done right!!
                    972: #
                    973: sub ToIdle {
                    974:     my $self   = shift;
                    975: 
                    976:     $self->Transition("Idle");
                    977:     $self->{InformWritiable} = 0;
                    978:     $self->{InformReadable}  = 0;
                    979:     $self->{Timeoutable}     = 0;
                    980: }
                    981: 
                    982: #  ToVersionRequest
                    983: #    Called to transition to "RequestVersion"  also done a few times
                    984: #    so worth subbing out.
                    985: #
                    986: sub ToVersionRequest {
                    987:     my $self   = shift;
                    988:     
                    989:     $self->Transition("RequestingVersion");
                    990:     $self->{InformReadable}   = 0;
                    991:     $self->{InformWritable}   = 1;
                    992:     $self->{TransactionRequest} = "version\n";
                    993:     
                    994: }
                    995: #
                    996: #  CreateCipher
                    997: #    Given a cipher key stores the key in the object context,
                    998: #    creates the cipher object, (stores that in object context),
                    999: #    This is done a couple of places, so it's worth factoring it out.
                   1000: #
                   1001: # Parameters:
                   1002: #    (self)
                   1003: #    key - The Cipher key.
                   1004: #
                   1005: # Returns:
                   1006: #    0   - Failure to create IDEA cipher.
                   1007: #    1   - Success.
                   1008: #
                   1009: sub CreateCipher {
                   1010:     my ($self, $key)   = @_;	# According to coding std.
                   1011: 
                   1012:     $self->{CipherKey} = $key; # Save the text key...
                   1013:     my $packedkey = pack ("H32", $key);
                   1014:     my $cipher            = new IDEA $packedkey;
                   1015:     if($cipher) {
                   1016: 	$self->{Cipher} = $cipher;
                   1017: 	Debug("Cipher created  dumping socket: ");
1.32      foxr     1018: 	$self->Dump(9);
1.31      foxr     1019: 	return 1;
                   1020:     }
                   1021:     else {
                   1022: 	return 0;
                   1023:     }
                   1024: }
                   1025: # ExchangeKeysViaSSL
                   1026: #     Called to do cipher key exchange via SSL.
                   1027: #     The socket is promoted to an SSL socket. If that's successful,
                   1028: #     we read out cipher key through the socket and create an IDEA
                   1029: #     cipher object.
                   1030: # Parameters:
                   1031: #    (self)
                   1032: # Returns:
                   1033: #      true    - Success.
                   1034: #      false   - Failure.
                   1035: #
                   1036: # Assumptions:
                   1037: #  1.   The ssl session setup has timeout logic built in so we don't
                   1038: #     have to worry about DOS attacks at that stage.
                   1039: #  2.   If the ssl session gets set up we are talking to a legitimate
                   1040: #     lond so again we don't have to worry about DOS attacks.
                   1041: #  All this allows us just to call 
                   1042: sub ExchangeKeysViaSSL {
                   1043:     my $self   = shift;
                   1044:     my $socket = $self->{Socket};
1.56    ! raeburn  1045:     my $peer = $self->{LoncapaHim};
1.31      foxr     1046: 
                   1047:     #  Get our signed certificate, the certificate authority's 
                   1048:     #  certificate and our private key file.  All of these
                   1049:     #  are needed to create the ssl connection.
                   1050: 
                   1051:     my ($SSLCACertificate,
                   1052: 	$SSLCertificate) = lonssl::CertificateFile();
                   1053:     my $SSLKey             = lonssl::KeyFile();
                   1054: 
                   1055:     #  Promote our connection to ssl and read the key from lond.
                   1056: 
                   1057:     my $SSLSocket = lonssl::PromoteClientSocket($socket,
                   1058: 						$SSLCACertificate,
                   1059: 						$SSLCertificate,
1.56    ! raeburn  1060: 						$SSLKey,
        !          1061:                                                 $peer);
1.31      foxr     1062:     if(defined $SSLSocket) {
                   1063: 	my $key  = <$SSLSocket>;
                   1064: 	lonssl::Close($SSLSocket);
                   1065: 	if($key) {
                   1066: 	    chomp($key);	# \n is not part of the key.
                   1067: 	    return $self->CreateCipher($key);
                   1068: 	} 
                   1069: 	else {
                   1070: 	    Debug(3, "Failed to read ssl key");
                   1071: 	    return 0;
                   1072: 	}
                   1073:     }
                   1074:     else {
                   1075: 	# Failed!!
                   1076: 	Debug(3, "Failed to negotiate SSL connection!");
1.56    ! raeburn  1077: 	return -1;
1.31      foxr     1078:     }
                   1079:     # should not get here
                   1080:     return 0;
                   1081: 
                   1082: }
                   1083: 
                   1084: 
                   1085: 
                   1086: #
                   1087: #  CompleteInsecure:
                   1088: #      This function is called to initiate the completion of
                   1089: #      insecure challenge response negotiation.
                   1090: #      To do this, we copy the challenge string to the transaction
                   1091: #      request, flip to writability and state transition to 
                   1092: #      ChallengeReceived..
                   1093: #      All this is only possible if InsecureOk is true.
                   1094: # Parameters:
                   1095: #      (self)    - This object's context hash.
                   1096: #  Return:
                   1097: #      0   - Ok to transition.
                   1098: #     -1   - Not ok to transition (InsecureOk not ok).
                   1099: #
                   1100: sub CompleteInsecure {
                   1101:     my $self = shift;
1.56    ! raeburn  1102:     if ($self->{InsecureOK}) {
1.31      foxr     1103: 	$self->{AuthenticationMode} = "insecure";
                   1104: 	&Debug(8," Transition out of Initialized:insecure");
                   1105: 	$self->{TransactionRequest} = $self->{TransactionReply};
                   1106: 	$self->{InformWritable}     = 1;
                   1107: 	$self->{InformReadable}     = 0;
                   1108: 	$self->Transition("ChallengeReceived");
                   1109: 	$self->{TimeoutRemaining}   = $self->{TimeoutValue};
                   1110: 	return 0;
                   1111: 	
                   1112: 	
                   1113:     }
                   1114:     else {
                   1115: 	&Debug(3, "Insecure key negotiation disabled!");
                   1116: 	my $socket = $self->{Socket};
                   1117: 	$socket->close;
                   1118: 	return -1;
                   1119:     }
                   1120: }
1.1       foxr     1121: 
1.14      foxr     1122: ###########################################################
                   1123: #
                   1124: #  The following is an unashamed kludge that is here to
                   1125: # allow LondConnection to be used outside of the
                   1126: # loncapa environment (e.g. by lonManage).
                   1127: # 
                   1128: #   This is a textual inclusion of pieces of the
                   1129: #   Configuration.pm module.
                   1130: #
                   1131: 
                   1132: 
1.43      raeburn  1133: my @confdirs=('/etc/httpd/conf/','/etc/apache2/');
1.14      foxr     1134: 
                   1135: # ------------------- Subroutine read_conf: read LON-CAPA server configuration.
                   1136: # This subroutine reads PerlSetVar values out of specified web server
                   1137: # configuration files.
                   1138: sub read_conf
                   1139:   {
                   1140:     my (@conf_files)=@_;
1.43      raeburn  1141:     my (%perlvar,%configdirs);
                   1142:     foreach my $filename (@conf_files,'loncapa_apache.conf') {
                   1143:         my $configdir = '';
                   1144:         $configdirs{$filename} = [@confdirs];
                   1145:         while ($configdir eq '' && @{$configdirs{$filename}} > 0) {
                   1146:             my $testdir = shift(@{$configdirs{$filename}});
                   1147:             if (-e $testdir.$filename) {
                   1148:                 $configdir = $testdir;
                   1149:             }
                   1150:         }
                   1151:         if ($configdir eq '') {
                   1152:             die("Couldn't find a directory containing $filename");
                   1153:         }
                   1154: 	if($DebugLevel > 3) {
                   1155: 	    print STDERR ("Going to read $configdir.$filename\n");
                   1156: 	}
                   1157: 	open(CONFIG,'<'.$configdir.$filename) or
                   1158: 	    die("Can't read $configdir$filename");
                   1159: 	while (my $configline=<CONFIG>) {
                   1160: 	    if ($configline =~ /^[^\#]*PerlSetVar/) {
                   1161: 	        my ($unused,$varname,$varvalue)=split(/\s+/,$configline);
1.14      foxr     1162: 		chomp($varvalue);
                   1163: 		$perlvar{$varname}=$varvalue;
1.43      raeburn  1164: 	    }
                   1165: 	}
1.14      foxr     1166: 	close(CONFIG);
1.43      raeburn  1167:     }
1.21      foxr     1168:     if($DebugLevel > 3) {
1.31      foxr     1169: 	print STDERR "Dumping perlvar:\n";
1.21      foxr     1170: 	foreach my $var (keys %perlvar) {
1.31      foxr     1171: 	    print STDERR "$var = $perlvar{$var}\n";
1.21      foxr     1172: 	}
                   1173:     }
1.14      foxr     1174:     my $perlvarref=\%perlvar;
1.21      foxr     1175:     return $perlvarref;
                   1176: }
1.14      foxr     1177: 
1.24      foxr     1178: #
                   1179: #   Get the version of our peer.  Note that this is only well
                   1180: #   defined if the state machine has hit the idle state at least
                   1181: #   once (well actually if it has transitioned out of 
                   1182: #   ReadingVersionString   The member data LondVersion is returned.
                   1183: #
                   1184: sub PeerVersion {
                   1185:    my $self = shift;
1.40      albertel 1186:    my ($version) = ($self->{LondVersion} =~ /Revision: 1\.(\d+)/);
                   1187:    return $version;
1.24      foxr     1188: }
1.1       foxr     1189: 
1.52      foxr     1190: #
                   1191: #  Manipulate the client data field
                   1192: #
                   1193: sub SetClientData {
                   1194:     my ($self, $newData) = @_;
                   1195:     $self->{ClientData} = $newData;
                   1196: }
                   1197: #
                   1198: #  Get the current client data field.
                   1199: #
                   1200: sub GetClientData {
                   1201:     my $self = shift;
                   1202:     return $self->{ClientData};
                   1203: }
                   1204: 
1.55      raeburn  1205: #
                   1206: # Get the HostID of our peer 
                   1207: #
                   1208: 
                   1209: sub PeerLoncapaHim {
                   1210:     my $self = shift;
                   1211:     return $self->{LoncapaHim};
                   1212: }
                   1213: 
1.1       foxr     1214: 1;
                   1215: 
                   1216: =pod
1.3       albertel 1217: 
1.1       foxr     1218: =head1 Theory
                   1219: 
1.3       albertel 1220: The lond object is a state machine.  It lives through the following states:
                   1221: 
                   1222: =item Connected:
                   1223: 
                   1224: a TCP connection has been formed, but the passkey has not yet been
                   1225: negotiated.
                   1226: 
                   1227: =item Initialized:
                   1228: 
                   1229: "init" sent.
                   1230: 
                   1231: =item ChallengeReceived:
                   1232: 
                   1233: lond sent its challenge to us.
                   1234: 
                   1235: =item ChallengeReplied:
                   1236: 
                   1237: We replied to lond's challenge waiting for lond's ok.
                   1238: 
                   1239: =item RequestingKey:
                   1240: 
                   1241: We are requesting an encryption key.
                   1242: 
                   1243: =item ReceivingKey:
                   1244: 
                   1245: We are receiving an encryption key.
                   1246: 
                   1247: =item Idle:
                   1248: 
                   1249: Connection was negotiated but no requests are active.
                   1250: 
                   1251: =item SendingRequest:
                   1252: 
                   1253: A request is being sent to the peer.
                   1254: 
                   1255: =item ReceivingReply:
                   1256: 
                   1257: Waiting for an entire reply from the peer.
                   1258: 
                   1259: =item Disconnected:
                   1260: 
                   1261: For whatever reason, the connection was dropped.
                   1262: 
                   1263: When we need to be writing data, we have a writable event. When we
                   1264: need to be reading data, a readable event established.  Events
                   1265: dispatch through the class functions Readable and Writable, and the
                   1266: watcher contains a reference to the associated object to allow object
                   1267: context to be reached.
1.1       foxr     1268: 
                   1269: =head2 Member data.
                   1270: 
1.3       albertel 1271: =item Host
                   1272: 
                   1273: Host socket is connected to.
                   1274: 
                   1275: =item Port
                   1276: 
                   1277: The port the remote lond is listening on.
                   1278: 
                   1279: =item Socket
                   1280: 
                   1281: Socket open on the connection.
                   1282: 
                   1283: =item State
                   1284: 
                   1285: The current state.
                   1286: 
1.31      foxr     1287: =item AuthenticationMode
                   1288: 
                   1289: How authentication is being done. This can be any of:
                   1290: 
                   1291:     o local - Authenticate via a key exchanged in a file.
                   1292:     o ssl   - Authenticate via a key exchaned through a temporary ssl tunnel.
                   1293:     o insecure - Exchange keys in an insecure manner.
                   1294: 
                   1295: insecure is only allowed if the configuration parameter loncAllowInsecure 
                   1296: is nonzero.
                   1297: 
1.3       albertel 1298: =item TransactionRequest
                   1299: 
                   1300: The request being transmitted.
                   1301: 
                   1302: =item TransactionReply
                   1303: 
                   1304: The reply being received from the transaction.
                   1305: 
                   1306: =item InformReadable
                   1307: 
                   1308: True if we want to be called when socket is readable.
                   1309: 
                   1310: =item InformWritable
                   1311: 
                   1312: True if we want to be informed if the socket is writable.
                   1313: 
                   1314: =item Timeoutable
                   1315: 
                   1316: True if the current operation is allowed to timeout.
                   1317: 
                   1318: =item TimeoutValue
                   1319: 
                   1320: Number of seconds in the timeout.
                   1321: 
                   1322: =item TimeoutRemaining
                   1323: 
                   1324: Number of seconds left in the timeout.
                   1325: 
                   1326: =item CipherKey
                   1327: 
                   1328: The key that was negotiated with the peer.
                   1329: 
                   1330: =item Cipher
                   1331: 
                   1332: The cipher obtained via the key.
1.1       foxr     1333: 
                   1334: 
                   1335: =head2 The following are callback like members:
1.3       albertel 1336: 
                   1337: =item Tick:
                   1338: 
                   1339: Called in response to a timer tick. Used to managed timeouts etc.
                   1340: 
                   1341: =item Readable:
                   1342: 
                   1343: Called when the socket becomes readable.
                   1344: 
                   1345: =item Writable:
                   1346: 
                   1347: Called when the socket becomes writable.
                   1348: 
                   1349: =item TimedOut:
                   1350: 
                   1351: Called when a timed operation timed out.
                   1352: 
1.1       foxr     1353: 
                   1354: =head2 The following are operational member functions.
1.3       albertel 1355: 
                   1356: =item InitiateTransaction:
                   1357: 
                   1358: Called to initiate a new transaction
                   1359: 
                   1360: =item SetStateTransitionCallback:
                   1361: 
                   1362: Called to establish a function that is called whenever the object goes
                   1363: through a state transition.  This is used by The client to manage the
                   1364: work flow for the object.
                   1365: 
                   1366: =item SetTimeoutCallback:
                   1367: 
                   1368: Set a function to be called when a transaction times out.  The
                   1369: function will be called with the object as its sole parameter.
                   1370: 
                   1371: =item Encrypt:
                   1372: 
                   1373: Encrypts a block of text according to the cipher negotiated with the
                   1374: peer (assumes the text is a command).
                   1375: 
                   1376: =item Decrypt:
                   1377: 
                   1378: Decrypts a block of text according to the cipher negotiated with the
                   1379: peer (assumes the block was a reply.
1.5       foxr     1380: 
                   1381: =item Shutdown:
                   1382: 
                   1383: Shuts off the socket.
1.1       foxr     1384: 
                   1385: =head2 The following are selector member functions:
                   1386: 
1.3       albertel 1387: =item GetState:
                   1388: 
                   1389: Returns the current state
                   1390: 
                   1391: =item GetSocket:
                   1392: 
                   1393: Gets the socekt open on the connection to lond.
                   1394: 
                   1395: =item WantReadable:
                   1396: 
                   1397: true if the current state requires a readable event.
                   1398: 
                   1399: =item WantWritable:
                   1400: 
                   1401: true if the current state requires a writable event.
                   1402: 
                   1403: =item WantTimeout:
                   1404: 
                   1405: true if the current state requires timeout support.
                   1406: 
1.1       foxr     1407: =cut

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