--- loncom/LondConnection.pm 2004/02/09 10:57:37 1.24 +++ loncom/LondConnection.pm 2004/09/21 10:51:42 1.35 @@ -1,7 +1,7 @@ # This module defines and implements a class that represents # a connection to a lond daemon. # -# $Id: LondConnection.pm,v 1.24 2004/02/09 10:57:37 foxr Exp $ +# $Id: LondConnection.pm,v 1.35 2004/09/21 10:51:42 foxr Exp $ # # Copyright Michigan State University Board of Trustees # @@ -36,7 +36,8 @@ use IO::File; use Fcntl; use POSIX; use Crypt::IDEA; - +use LONCAPA::lonlocal; +use LONCAPA::lonssl; @@ -44,6 +45,8 @@ use Crypt::IDEA; my $DebugLevel=0; my %hostshash; my %perlvar; +my $LocalDns = ""; # Need not be defined for managers. +my $InsecureOk; # # Set debugging level @@ -61,9 +64,11 @@ sub SetDebug { my $ConfigRead = 0; # Read the configuration file for apache to get the perl -# variable set. +# variables set. sub ReadConfig { + Debug(8, "ReadConfig called"); + my $perlvarref = read_conf('loncapa.conf'); %perlvar = %{$perlvarref}; my $hoststab = read_hosts( @@ -72,6 +77,18 @@ sub ReadConfig { %hostshash = %{$hoststab}; $ConfigRead = 1; + my $myLonCapaName = $perlvar{lonHostID}; + Debug(8, "My loncapa name is $myLonCapaName"); + + if(defined $hostshash{$myLonCapaName}) { + Debug(8, "My loncapa name is in hosthash"); + my @ConfigLine = @{$hostshash{$myLonCapaName}}; + $LocalDns = $ConfigLine[3]; + Debug(8, "Got local name $LocalDns"); + } + $InsecureOk = $perlvar{loncAllowInsecure}; + + Debug(3, "ReadConfig - LocalDNS = $LocalDns"); } # @@ -89,8 +106,8 @@ sub ReadConfig { # to build up the hosts table. # sub ReadForeignConfig { - my $MyHost = shift; - my $Filename = shift; + + my ($MyHost, $Filename) = @_; &Debug(4, "ReadForeignConfig $MyHost $Filename\n"); @@ -100,18 +117,29 @@ sub ReadForeignConfig { %hostshash = %{$hosttab}; if($DebugLevel > 3) { foreach my $host (keys %hostshash) { - print "host $host => $hostshash{$host}\n"; + print STDERR "host $host => $hostshash{$host}\n"; } } $ConfigRead = 1; + my $myLonCapaName = $perlvar{lonHostID}; + + if(defined $hostshash{$myLonCapaName}) { + my @ConfigLine = @{$hostshash{$myLonCapaName}}; + $LocalDns = $ConfigLine[3]; + } + $InsecureOk = $perlvar{loncAllowInsecure}; + + Debug(3, "ReadForeignConfig - LocalDNS = $LocalDns"); + } sub Debug { - my $level = shift; - my $message = shift; + + my ($level, $message) = @_; + if ($level < $DebugLevel) { - print($message."\n"); + print STDERR ($message."\n"); } } @@ -125,9 +153,18 @@ Dump the internal state of the object: F sub Dump { my $self = shift; + my $level = shift; + my $now = time; + my $local = localtime($now); + + if ($level <= $DebugLevel) { + return; + } + + my $key; my $value; - print STDERR "Dumping LondConnectionObject:\n"; + print STDERR "[ $local ] Dumping LondConnectionObject:\n"; while(($key, $value) = each %$self) { print STDERR "$key -> $value\n"; } @@ -143,8 +180,9 @@ old state. =cut sub Transition { - my $self = shift; - my $newstate = shift; + + my ($self, $newstate) = @_; + my $oldstate = $self->{State}; $self->{State} = $newstate; $self->{TimeoutRemaining} = $self->{TimeoutValue}; @@ -174,9 +212,8 @@ host the remote lond is on. This host is =cut sub new { - my $class = shift; # class name. - my $Hostname = shift; # Name of host to connect to. - my $Port = shift; # Port to connect + + my ($class, $Hostname, $Port) = @_; if (!$ConfigRead) { ReadConfig(); @@ -202,6 +239,7 @@ sub new { LoncapaHim => $Hostname, Port => $Port, State => "Initialized", + AuthenticationMode => "", TransactionRequest => "", TransactionReply => "", InformReadable => 0, @@ -211,6 +249,7 @@ sub new { Timeoutable => 0, TimeoutValue => 30, TimeoutRemaining => 0, + LocalKeyFile => "", CipherKey => "", LondVersion => "Unknown", Cipher => undef}; @@ -222,30 +261,90 @@ sub new { Timeout => 3)) { return undef; # Inidicates the socket could not be made. } + my $socket = $self->{Socket}; # For local use only. + # If we are local, we'll first try local auth mode, otherwise, we'll try + # the ssl auth mode: + + Debug(8, "Connecting to $DnsName I am $LocalDns"); + my $key; + my $keyfile; + if ($DnsName eq $LocalDns) { + $self->{AuthenticationMode} = "local"; + ($key, $keyfile) = lonlocal::CreateKeyFile(); + Debug(8, "Local key: $key, stored in $keyfile"); + + # If I can't make the key file fall back to insecure if + # allowed...else give up right away. + + if(!(defined $key) || !(defined $keyfile)) { + if($InsecureOk) { + $self->{AuthenticationMode} = "insecure"; + $self->{TransactionRequest} = "init\n"; + } + else { + $socket->close; + return undef; + } + } + $self->{TransactionRequest} = "init:local:$keyfile\n"; + Debug(9, "Init string is init:local:$keyfile"); + if(!$self->CreateCipher($key)) { # Nothing's going our way... + $socket->close; + return undef; + } + + } + else { + # Remote peer: I'd like to do ssl, but if my host key or certificates + # are not all installed, my only choice is insecure, if that's + # allowed: + + my ($ca, $cert) = lonssl::CertificateFile; + my $sslkeyfile = lonssl::KeyFile; + + if((defined $ca) && (defined $cert) && (defined $sslkeyfile)) { + + $self->{AuthenticationMode} = "ssl"; + $self->{TransactionRequest} = "init:ssl\n"; + } else { + if($InsecureOk) { # Allowed to do insecure: + $self->{AuthenticationMode} = "insecure"; + $self->{TransactionRequest} = "init\n"; + } + else { # Not allowed to do insecure... + $socket->close; + return undef; + } + } + } + # # We're connected. Set the state, and the events we'll accept: # $self->Transition("Connected"); $self->{InformWritable} = 1; # When socket is writable we send init $self->{Timeoutable} = 1; # Timeout allowed during startup negotiation. - $self->{TransactionRequest} = "init\n"; + # # Set socket to nonblocking I/O. # my $socket = $self->{Socket}; - my $flags = fcntl($socket->fileno, F_GETFL,0); - if($flags == -1) { + my $flags = fcntl($socket, F_GETFL,0); + if(!$flags) { $socket->close; return undef; } - if(fcntl($socket, F_SETFL, $flags | O_NONBLOCK) == -1) { + if(!fcntl($socket, F_SETFL, $flags | O_NONBLOCK)) { $socket->close; return undef; } # return the object : + Debug(9, "Initial object state: "); + $self->Dump(9); + return $self; } @@ -279,7 +378,17 @@ sub Readable { my $self = shift; my $socket = $self->{Socket}; my $data = ''; - my $rv = $socket->recv($data, POSIX::BUFSIZ, 0); + my $rv; + my $ConnectionMode = $self->{AuthenticationMode}; + + if ($socket) { + eval { + $rv = $socket->recv($data, POSIX::BUFSIZ, 0); + } + } else { + $self->Transition("Disconnected"); + return -1; + } my $errno = $! + 0; # Force numeric context. unless (defined($rv) && length $data) {# Read failed, @@ -300,72 +409,143 @@ sub Readable { &Debug(9,"Received from host: ".$data); $self->{TransactionReply} .= $data; - if($self->{TransactionReply} =~ /(.*\n)/) { + if($self->{TransactionReply} =~ m/\n$/) { &Debug(8,"Readable End of line detected"); + + if ($self->{State} eq "Initialized") { # We received the challenge: - if($self->{TransactionReply} eq "refused\n") { # Remote doesn't have - - $self->Transition("Disconnected"); # in host tables. + # Our init was replied to. What happens next depends both on + # the actual init we sent (AuthenticationMode member data) + # and the response: + # AuthenticationMode == local: + # Response ok: The key has been exchanged and + # the key file destroyed. We can jump + # into setting the host and requesting the + # Later we'll also bypass key exchange. + # Response digits: + # Old style lond. Delete the keyfile. + # If allowed fall back to insecure mode. + # else close connection and fail. + # Response other: + # Failed local auth + # Close connection and fail. + # + # AuthenticationMode == ssl: + # Response ok:ssl + # Response digits: + # Response other: + # Authentication mode == insecure + # Response digits + # Response other: + + my $Response = $self->{TransactionReply}; + if($ConnectionMode eq "local") { + if($Response =~ /^ok:local/) { # Good local auth. + $self->ToVersionRequest(); + return 0; + } + elsif ($Response =~/^[0-9]+/) { # Old style lond. + return $self->CompleteInsecure(); + + } + else { # Complete flop + &Debug(3, "init:local : unrecognized reply"); + $self->Transition("Disconnected"); + $socket->close; + return -1; + } + } + elsif ($ConnectionMode eq "ssl") { + if($Response =~ /^ok:ssl/) { # Good ssl... + if($self->ExchangeKeysViaSSL()) { # Success skip to vsn stuff + # Need to reset to non blocking: + + my $flags = fcntl($socket, F_GETFL, 0); + fcntl($socket, F_SETFL, $flags | O_NONBLOCK); + $self->ToVersionRequest(); + return 0; + } + else { # Failed in ssl exchange. + &Debug(3,"init:ssl failed key negotiation!"); + $self->Transition("Disconnected"); + $socket->close; + return -1; + } + } + elsif ($Response =~ /^[0-9]+/) { # Old style lond. + return $self->CompleteInsecure(); + } + else { # Complete flop + } + } + elsif ($ConnectionMode eq "insecure") { + if($self->{TransactionReply} eq "refused\n") { # Remote doesn't have + + $self->Transition("Disconnected"); # in host tables. + $socket->close(); + return -1; + + } + return $self->CompleteInsecure(); + } + else { + &Debug(1,"Authentication mode incorrect"); + die "BUG!!! LondConnection::Readable invalid authmode"; + } + + + } elsif ($self->{State} eq "ChallengeReplied") { + if($self->{TransactionReply} ne "ok\n") { + $self->Transition("Disconnected"); $socket->close(); return -1; } + $self->ToVersionRequest(); + return 0; - &Debug(8," Transition out of Initialized"); - $self->{TransactionRequest} = $self->{TransactionReply}; - $self->{InformWritable} = 1; - $self->{InformReadable} = 0; - $self->Transition("ChallengeReceived"); - $self->{TimeoutRemaining} = $self->{TimeoutValue}; + } elsif ($self->{State} eq "ReadingVersionString") { + $self->{LondVersion} = chomp($self->{TransactionReply}); + $self->Transition("SetHost"); + $self->{InformReadable} = 0; + $self->{InformWritable} = 1; + my $peer = $self->{LoncapaHim}; + $self->{TransactionRequest}= "sethost:$peer\n"; return 0; - } elsif ($self->{State} eq "ChallengeReplied") { - if($self->{TransactionReply} ne "ok\n") { - $self->Transition("Disconnected"); - $socket->close(); - return -1; - } - $self->Transition("RequestingVersion"); - $self->{InformReadable} = 0; - $self->{InformWritable} = 1; - $self->{TransactionRequest} = "version\n"; - return 0; - } elsif ($self->{State} eq "ReadingVersionString") { - $self->{LondVersion} = chomp($self->{TransactionReply}); - $self->Transition("SetHost"); - $self->{InformReadable} = 0; - $self->{InformWritable} = 1; - my $peer = $self->{LoncapaHim}; - $self->{TransactionRequest}= "sethost:$peer\n"; - return 0; } elsif ($self->{State} eq "HostSet") { # should be ok. - if($self->{TransactionReply} ne "ok\n") { - $self->Transition("Disconnected"); - $socket->close(); - return -1; - } - $self->Transition("RequestingKey"); - $self->{InformReadable} = 0; - $self->{InformWritable} = 1; - $self->{TransactionRequest} = "ekey\n"; - return 0; + if($self->{TransactionReply} ne "ok\n") { + $self->Transition("Disconnected"); + $socket->close(); + return -1; + } + # If the auth mode is insecure we must still + # exchange session keys. Otherwise, + # we can just transition to idle. + + if($ConnectionMode eq "insecure") { + $self->Transition("RequestingKey"); + $self->{InformReadable} = 0; + $self->{InformWritable} = 1; + $self->{TransactionRequest} = "ekey\n"; + return 0; + } + else { + $self->ToIdle(); + return 0; + } } elsif ($self->{State} eq "ReceivingKey") { my $buildkey = $self->{TransactionReply}; my $key = $self->{LoncapaHim}.$perlvar{'lonHostID'}; $key=~tr/a-z/A-Z/; $key=~tr/G-P/0-9/; $key=~tr/Q-Z/0-9/; - $key=$key.$buildkey.$key.$buildkey.$key.$buildkey; - $key=substr($key,0,32); - my $cipherkey=pack("H32",$key); - $self->{Cipher} = new IDEA $cipherkey; - if($self->{Cipher} eq undef) { + $key =$key.$buildkey.$key.$buildkey.$key.$buildkey; + $key = substr($key,0,32); + if(!$self->CreateCipher($key)) { $self->Transition("Disconnected"); $socket->close(); return -1; } else { - $self->Transition("Idle"); - $self->{InformWritable} = 0; - $self->{InformReadable} = 0; - $self->{Timeoutable} = 0; + $self->ToIdle(); return 0; } } elsif ($self->{State} eq "ReceivingReply") { @@ -375,15 +555,12 @@ sub Readable { my $answer = $self->{TransactionReply}; if($answer =~ /^enc\:/) { $answer = $self->Decrypt($answer); - $self->{TransactionReply} = $answer; + $self->{TransactionReply} = "$answer\n"; } # finish the transaction - $self->{InformWritable} = 0; - $self->{InformReadable} = 0; - $self->{Timeoutable} = 0; - $self->Transition("Idle"); + $self->ToIdle(); return 0; } elsif ($self->{State} eq "Disconnected") { # No connection. return -1; @@ -413,7 +590,18 @@ Returns 0 if successful, or -1 if not. sub Writable { my $self = shift; # Get reference to the object. my $socket = $self->{Socket}; - my $nwritten = $socket->send($self->{TransactionRequest}, 0); + my $nwritten; + if ($socket) { + eval { + $nwritten = $socket->send($self->{TransactionRequest}, 0); + } + } else { + # For whatever reason, there's no longer a socket left. + + + $self->Transition("Disconnected"); + return -1; + } my $errno = $! + 0; unless (defined $nwritten) { if($errno != POSIX::EINTR) { @@ -516,8 +704,8 @@ timout, and to request writability notif =cut sub InitiateTransaction { - my $self = shift; - my $data = shift; + + my ($self, $data) = @_; Debug(1, "initiating transaction: ".$data); if($self->{State} ne "Idle") { @@ -568,8 +756,9 @@ established callback or undef if there w =cut sub SetTimeoutCallback { - my $self = shift; - my $callback = shift; + + my ($self, $callback) = @_; + my $oldCallback = $self->{TimeoutCallback}; $self->{TimeoutCallback} = $callback; return $oldCallback; @@ -697,8 +886,8 @@ The output string can be directly sent t =cut sub Encrypt { - my $self = shift; # Reference to the object. - my $request = shift; # Text to send. + + my ($self, $request) = @_; # Split the encrypt: off the request and figure out it's length. @@ -740,8 +929,8 @@ Decrypt a response from the server. The =cut sub Decrypt { - my $self = shift; # Recover reference to object - my $encrypted = shift; # This is the encrypted data. + + my ($self, $encrypted) = @_; # Bust up the response into length, and encryptedstring: @@ -764,10 +953,161 @@ sub Decrypt { # $length tells us the actual length of the decrypted string: $decrypted = substr($decrypted, 0, $length); + Debug(9, "Decrypted $EncryptedString to $decrypted"); return $decrypted; } +# ToIdle +# Called to transition to idle... done enough it's worth subbing +# off to ensure it's always done right!! +# +sub ToIdle { + my $self = shift; + + $self->Transition("Idle"); + $self->{InformWritiable} = 0; + $self->{InformReadable} = 0; + $self->{Timeoutable} = 0; +} + +# ToVersionRequest +# Called to transition to "RequestVersion" also done a few times +# so worth subbing out. +# +sub ToVersionRequest { + my $self = shift; + + $self->Transition("RequestingVersion"); + $self->{InformReadable} = 0; + $self->{InformWritable} = 1; + $self->{TransactionRequest} = "version\n"; + +} +# +# CreateCipher +# Given a cipher key stores the key in the object context, +# creates the cipher object, (stores that in object context), +# This is done a couple of places, so it's worth factoring it out. +# +# Parameters: +# (self) +# key - The Cipher key. +# +# Returns: +# 0 - Failure to create IDEA cipher. +# 1 - Success. +# +sub CreateCipher { + my ($self, $key) = @_; # According to coding std. + + $self->{CipherKey} = $key; # Save the text key... + my $packedkey = pack ("H32", $key); + my $cipher = new IDEA $packedkey; + if($cipher) { + $self->{Cipher} = $cipher; + Debug("Cipher created dumping socket: "); + $self->Dump(9); + return 1; + } + else { + return 0; + } +} +# ExchangeKeysViaSSL +# Called to do cipher key exchange via SSL. +# The socket is promoted to an SSL socket. If that's successful, +# we read out cipher key through the socket and create an IDEA +# cipher object. +# Parameters: +# (self) +# Returns: +# true - Success. +# false - Failure. +# +# Assumptions: +# 1. The ssl session setup has timeout logic built in so we don't +# have to worry about DOS attacks at that stage. +# 2. If the ssl session gets set up we are talking to a legitimate +# lond so again we don't have to worry about DOS attacks. +# All this allows us just to call +sub ExchangeKeysViaSSL { + my $self = shift; + my $socket = $self->{Socket}; + + # Get our signed certificate, the certificate authority's + # certificate and our private key file. All of these + # are needed to create the ssl connection. + + my ($SSLCACertificate, + $SSLCertificate) = lonssl::CertificateFile(); + my $SSLKey = lonssl::KeyFile(); + + # Promote our connection to ssl and read the key from lond. + + my $SSLSocket = lonssl::PromoteClientSocket($socket, + $SSLCACertificate, + $SSLCertificate, + $SSLKey); + if(defined $SSLSocket) { + my $key = <$SSLSocket>; + lonssl::Close($SSLSocket); + if($key) { + chomp($key); # \n is not part of the key. + return $self->CreateCipher($key); + } + else { + Debug(3, "Failed to read ssl key"); + return 0; + } + } + else { + # Failed!! + Debug(3, "Failed to negotiate SSL connection!"); + return 0; + } + # should not get here + return 0; + +} + + + +# +# CompleteInsecure: +# This function is called to initiate the completion of +# insecure challenge response negotiation. +# To do this, we copy the challenge string to the transaction +# request, flip to writability and state transition to +# ChallengeReceived.. +# All this is only possible if InsecureOk is true. +# Parameters: +# (self) - This object's context hash. +# Return: +# 0 - Ok to transition. +# -1 - Not ok to transition (InsecureOk not ok). +# +sub CompleteInsecure { + my $self = shift; + if($InsecureOk) { + $self->{AuthenticationMode} = "insecure"; + &Debug(8," Transition out of Initialized:insecure"); + $self->{TransactionRequest} = $self->{TransactionReply}; + $self->{InformWritable} = 1; + $self->{InformReadable} = 0; + $self->Transition("ChallengeReceived"); + $self->{TimeoutRemaining} = $self->{TimeoutValue}; + return 0; + + + } + else { + &Debug(3, "Insecure key negotiation disabled!"); + my $socket = $self->{Socket}; + $socket->close; + return -1; + } +} =pod @@ -817,7 +1157,7 @@ sub read_conf foreach my $filename (@conf_files,'loncapa_apache.conf') { if($DebugLevel > 3) { - print("Going to read $confdir.$filename\n"); + print STDERR ("Going to read $confdir.$filename\n"); } open(CONFIG,'<'.$confdir.$filename) or die("Can't read $confdir$filename"); @@ -833,9 +1173,9 @@ sub read_conf close(CONFIG); } if($DebugLevel > 3) { - print "Dumping perlvar:\n"; + print STDERR "Dumping perlvar:\n"; foreach my $var (keys %perlvar) { - print "$var = $perlvar{$var}\n"; + print STDERR "$var = $perlvar{$var}\n"; } } my $perlvarref=\%perlvar; @@ -965,6 +1305,17 @@ Socket open on the connection. The current state. +=item AuthenticationMode + +How authentication is being done. This can be any of: + + o local - Authenticate via a key exchanged in a file. + o ssl - Authenticate via a key exchaned through a temporary ssl tunnel. + o insecure - Exchange keys in an insecure manner. + +insecure is only allowed if the configuration parameter loncAllowInsecure +is nonzero. + =item TransactionRequest The request being transmitted.