util/TLSProxy/Message.pm - third_party/openssl - Git at Google

 # Written by Matt Caswell for the OpenSSL project.
 # ====================================================================
 # Copyright (c) 1998-2015 The OpenSSL Project.  All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 #
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 #
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in
 #    the documentation and/or other materials provided with the
 #    distribution.
 #
 # 3. All advertising materials mentioning features or use of this
 #    software must display the following acknowledgment:
 #    "This product includes software developed by the OpenSSL Project
 #    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 #
 # 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 #    endorse or promote products derived from this software without
 #    prior written permission. For written permission, please contact
 #    openssl-core@openssl.org.
 #
 # 5. Products derived from this software may not be called "OpenSSL"
 #    nor may "OpenSSL" appear in their names without prior written
 #    permission of the OpenSSL Project.
 #
 # 6. Redistributions of any form whatsoever must retain the following
 #    acknowledgment:
 #    "This product includes software developed by the OpenSSL Project
 #    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 #
 # THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 # EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 # PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 # ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 # NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 # STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 # ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 # OF THE POSSIBILITY OF SUCH DAMAGE.
 # ====================================================================
 #
 # This product includes cryptographic software written by Eric Young
 # (eay@cryptsoft.com).  This product includes software written by Tim
 # Hudson (tjh@cryptsoft.com).

 use strict;

 package TLSProxy::Message;

 use constant TLS_MESSAGE_HEADER_LENGTH => 4;

 #Message types
 use constant {
     MT_HELLO_REQUEST => 0,
     MT_CLIENT_HELLO => 1,
     MT_SERVER_HELLO => 2,
     MT_NEW_SESSION_TICKET => 4,
     MT_CERTIFICATE => 11,
     MT_SERVER_KEY_EXCHANGE => 12,
     MT_CERTIFICATE_REQUEST => 13,
     MT_SERVER_HELLO_DONE => 14,
     MT_CERTIFICATE_VERIFY => 15,
     MT_CLIENT_KEY_EXCHANGE => 16,
     MT_FINISHED => 20,
     MT_CERTIFICATE_STATUS => 22,
     MT_NEXT_PROTO => 67
 };

 #Alert levels
 use constant {
     AL_LEVEL_WARN => 1,
     AL_LEVEL_FATAL => 2
 };

 #Alert descriptions
 use constant {
     AL_DESC_CLOSE_NOTIFY => 0
 };

 my %message_type = (
     MT_HELLO_REQUEST, "HelloRequest",
     MT_CLIENT_HELLO, "ClientHello",
     MT_SERVER_HELLO, "ServerHello",
     MT_NEW_SESSION_TICKET, "NewSessionTicket",
     MT_CERTIFICATE, "Certificate",
     MT_SERVER_KEY_EXCHANGE, "ServerKeyExchange",
     MT_CERTIFICATE_REQUEST, "CertificateRequest",
     MT_SERVER_HELLO_DONE, "ServerHelloDone",
     MT_CERTIFICATE_VERIFY, "CertificateVerify",
     MT_CLIENT_KEY_EXCHANGE, "ClientKeyExchange",
     MT_FINISHED, "Finished",
     MT_CERTIFICATE_STATUS, "CertificateStatus",
     MT_NEXT_PROTO, "NextProto"
 );

 my $payload = "";
 my $messlen = -1;
 my $mt;
 my $startoffset = -1;
 my $server = 0;
 my $success = 0;
 my $end = 0;
 my @message_rec_list = ();
 my @message_frag_lens = ();
 my $ciphersuite = 0;

 sub clear
 {
     $payload = "";
     $messlen = -1;
     $startoffset = -1;
     $server = 0;
     $success = 0;
     $end = 0;
     @message_rec_list = ();
     @message_frag_lens = ();
 }

 #Class method to extract messages from a record
 sub get_messages
 {
     my $class = shift;
     my $serverin = shift;
     my $record = shift;
     my @messages = ();
     my $message;

     @message_frag_lens = ();

     if ($serverin != $server && length($payload) != 0) {
         die "Changed peer, but we still have fragment data\n";
     }
     $server = $serverin;

     if ($record->content_type == TLSProxy::Record::RT_CCS) {
         if ($payload ne "") {
             #We can't handle this yet
             die "CCS received before message data complete\n";
         }
         if ($server) {
             TLSProxy::Record->server_ccs_seen(1);
         } else {
             TLSProxy::Record->client_ccs_seen(1);
         }
     } elsif ($record->content_type == TLSProxy::Record::RT_HANDSHAKE) {
         if ($record->len == 0 || $record->len_real == 0) {
             print "  Message truncated\n";
         } else {
             my $recoffset = 0;

             if (length $payload > 0) {
                 #We are continuing processing a message started in a previous
                 #record. Add this record to the list associated with this
                 #message
                 push @message_rec_list, $record;

                 if ($messlen <= length($payload)) {
                     #Shouldn't happen
                     die "Internal error: invalid messlen: ".$messlen
                         ." payload length:".length($payload)."\n";
                 }
                 if (length($payload) + $record->decrypt_len >= $messlen) {
                     #We can complete the message with this record
                     $recoffset = $messlen - length($payload);
                     $payload .= substr($record->decrypt_data, 0, $recoffset);
                     push @message_frag_lens, $recoffset;
                     $message = create_message($server, $mt, $payload,
                                               $startoffset);
                     push @messages, $message;

                     $payload = "";
                 } else {
                     #This is just part of the total message
                     $payload .= $record->decrypt_data;
                     $recoffset = $record->decrypt_len;
                     push @message_frag_lens, $record->decrypt_len;
                 }
                 print "  Partial message data read: ".$recoffset." bytes\n";
             }

             while ($record->decrypt_len > $recoffset) {
                 #We are at the start of a new message
                 if ($record->decrypt_len - $recoffset < 4) {
                     #Whilst technically probably valid we can't cope with this
                     die "End of record in the middle of a message header\n";
                 }
                 @message_rec_list = ($record);
                 my $lenhi;
                 my $lenlo;
                 ($mt, $lenhi, $lenlo) = unpack('CnC',
                                                substr($record->decrypt_data,
                                                       $recoffset));
                 $messlen = ($lenhi << 8) | $lenlo;
                 print "  Message type: $message_type{$mt}\n";
                 print "  Message Length: $messlen\n";
                 $startoffset = $recoffset;
                 $recoffset += 4;
                 $payload = "";

                 if ($recoffset < $record->decrypt_len) {
                     #Some payload data is present in this record
                     if ($record->decrypt_len - $recoffset >= $messlen) {
                         #We can complete the message with this record
                         $payload .= substr($record->decrypt_data, $recoffset,
                                            $messlen);
                         $recoffset += $messlen;
                         push @message_frag_lens, $messlen;
                         $message = create_message($server, $mt, $payload,
                                                   $startoffset);
                         push @messages, $message;

                         $payload = "";
                     } else {
                         #This is just part of the total message
                         $payload .= substr($record->decrypt_data, $recoffset,
                                            $record->decrypt_len - $recoffset);
                         $recoffset = $record->decrypt_len;
                         push @message_frag_lens, $recoffset;
                     }
                 }
             }
         }
     } elsif ($record->content_type == TLSProxy::Record::RT_APPLICATION_DATA) {
         print "  [ENCRYPTED APPLICATION DATA]\n";
         print "  [".$record->decrypt_data."]\n";
     } elsif ($record->content_type == TLSProxy::Record::RT_ALERT) {
         my ($alertlev, $alertdesc) = unpack('CC', $record->decrypt_data);
         #All alerts end the test
         $end = 1;
         #A CloseNotify from the client indicates we have finished successfully
         #(we assume)
         if (!$server && $alertlev == AL_LEVEL_WARN
             && $alertdesc == AL_DESC_CLOSE_NOTIFY) {
             $success = 1;
         }
     }

     return @messages;
 }

 #Function to work out which sub-class we need to create and then
 #construct it
 sub create_message
 {
     my ($server, $mt, $data, $startoffset) = @_;
     my $message;

     #We only support ClientHello in this version...needs to be extended for
     #others
     if ($mt == MT_CLIENT_HELLO) {
         $message = TLSProxy::ClientHello->new(
             $server,
             $data,
             [@message_rec_list],
             $startoffset,
             [@message_frag_lens]
         );
         $message->parse();
     } elsif ($mt == MT_SERVER_HELLO) {
         $message = TLSProxy::ServerHello->new(
             $server,
             $data,
             [@message_rec_list],
             $startoffset,
             [@message_frag_lens]
         );
         $message->parse();
     } elsif ($mt == MT_SERVER_KEY_EXCHANGE) {
         $message = TLSProxy::ServerKeyExchange->new(
             $server,
             $data,
             [@message_rec_list],
             $startoffset,
             [@message_frag_lens]
         );
         $message->parse();
     } elsif ($mt == MT_NEW_SESSION_TICKET) {
         $message = TLSProxy::NewSessionTicket->new(
             $server,
             $data,
             [@message_rec_list],
             $startoffset,
             [@message_frag_lens]
         );
         $message->parse();
     } else {
         #Unknown message type
         $message = TLSProxy::Message->new(
             $server,
             $mt,
             $data,
             [@message_rec_list],
             $startoffset,
             [@message_frag_lens]
         );
     }

     return $message;
 }

 sub end
 {
     my $class = shift;
     return $end;
 }
 sub success
 {
     my $class = shift;
     return $success;
 }
 sub fail
 {
     my $class = shift;
     return !$success && $end;
 }
 sub new
 {
     my $class = shift;
     my ($server,
         $mt,
         $data,
         $records,
         $startoffset,
         $message_frag_lens) = @_;

     my $self = {
         server => $server,
         data => $data,
         records => $records,
         mt => $mt,
         startoffset => $startoffset,
         message_frag_lens => $message_frag_lens
     };

     return bless $self, $class;
 }

 sub ciphersuite
 {
     my $class = shift;
     if (@_) {
       $ciphersuite = shift;
     }
     return $ciphersuite;
 }

 #Update all the underlying records with the modified data from this message
 #Note: Does not currently support re-encrypting
 sub repack
 {
     my $self = shift;
     my $msgdata;

     my $numrecs = $#{$self->records};

     $self->set_message_contents();

     my $lenhi;
     my $lenlo;

     $lenlo = length($self->data) & 0xff;
     $lenhi = length($self->data) >> 8;
     $msgdata = pack('CnC', $self->mt, $lenhi, $lenlo).$self->data;

     if ($numrecs == 0) {
         #The message is fully contained within one record
         my ($rec) = @{$self->records};
         my $recdata = $rec->decrypt_data;

         my $old_length;

         # We use empty message_frag_lens to indicates that pre-repacking,
         # the message wasn't present. The first fragment length doesn't include
         # the TLS header, so we need to check and compute the right length.
         if (@{$self->message_frag_lens}) {
             $old_length = ${$self->message_frag_lens}[0] +
               TLS_MESSAGE_HEADER_LENGTH;
         } else {
             $old_length = 0;
         }

         my $prefix = substr($recdata, 0, $self->startoffset);
         my $suffix = substr($recdata, $self->startoffset + $old_length);

         $rec->decrypt_data($prefix.($msgdata).($suffix));
         # TODO(openssl-team): don't keep explicit lengths.
         # (If a length override is ever needed to construct invalid packets,
         #  use an explicit override field instead.)
         $rec->decrypt_len(length($rec->decrypt_data));
         $rec->len($rec->len + length($msgdata) - $old_length);
         # Don't support re-encryption.
         $rec->data($rec->decrypt_data);

         #Update the fragment len in case we changed it above
         ${$self->message_frag_lens}[0] = length($msgdata)
                                          - TLS_MESSAGE_HEADER_LENGTH;
         return;
     }

     #Note we don't currently support changing a fragmented message length
     my $recctr = 0;
     my $datadone = 0;
     foreach my $rec (@{$self->records}) {
         my $recdata = $rec->decrypt_data;
         if ($recctr == 0) {
             #This is the first record
             my $remainlen = length($recdata) - $self->startoffset;
             $rec->data(substr($recdata, 0, $self->startoffset)
                        .substr(($msgdata), 0, $remainlen));
             $datadone += $remainlen;
         } elsif ($recctr + 1 == $numrecs) {
             #This is the last record
             $rec->data(substr($msgdata, $datadone));
         } else {
             #This is a middle record
             $rec->data(substr($msgdata, $datadone, length($rec->data)));
             $datadone += length($rec->data);
         }
         $recctr++;
     }
 }

 #To be overridden by sub-classes
 sub set_message_contents
 {
 }

 #Read only accessors
 sub server
 {
     my $self = shift;
     return $self->{server};
 }

 #Read/write accessors
 sub mt
 {
     my $self = shift;
     if (@_) {
       $self->{mt} = shift;
     }
     return $self->{mt};
 }
 sub data
 {
     my $self = shift;
     if (@_) {
       $self->{data} = shift;
     }
     return $self->{data};
 }
 sub records
 {
     my $self = shift;
     if (@_) {
       $self->{records} = shift;
     }
     return $self->{records};
 }
 sub startoffset
 {
     my $self = shift;
     if (@_) {
       $self->{startoffset} = shift;
     }
     return $self->{startoffset};
 }
 sub message_frag_lens
 {
     my $self = shift;
     if (@_) {
       $self->{message_frag_lens} = shift;
     }
     return $self->{message_frag_lens};
 }
 sub encoded_length
 {
     my $self = shift;
     return TLS_MESSAGE_HEADER_LENGTH + length($self->data);
 }

 1;
	# Written by Matt Caswell for the OpenSSL project.
	# ====================================================================
	# Copyright (c) 1998-2015 The OpenSSL Project. All rights reserved.
	#
	# Redistribution and use in source and binary forms, with or without
	# modification, are permitted provided that the following conditions
	# are met:
	#
	# 1. Redistributions of source code must retain the above copyright
	# notice, this list of conditions and the following disclaimer.
	#
	# 2. Redistributions in binary form must reproduce the above copyright
	# notice, this list of conditions and the following disclaimer in
	# the documentation and/or other materials provided with the
	# distribution.
	#
	# 3. All advertising materials mentioning features or use of this
	# software must display the following acknowledgment:
	# "This product includes software developed by the OpenSSL Project
	# for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
	#
	# 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
	# endorse or promote products derived from this software without
	# prior written permission. For written permission, please contact
	# openssl-core@openssl.org.
	#
	# 5. Products derived from this software may not be called "OpenSSL"
	# nor may "OpenSSL" appear in their names without prior written
	# permission of the OpenSSL Project.
	#
	# 6. Redistributions of any form whatsoever must retain the following
	# acknowledgment:
	# "This product includes software developed by the OpenSSL Project
	# for use in the OpenSSL Toolkit (http://www.openssl.org/)"
	#
	# THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
	# EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
	# ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	# STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
	# OF THE POSSIBILITY OF SUCH DAMAGE.
	# ====================================================================
	#
	# This product includes cryptographic software written by Eric Young
	# (eay@cryptsoft.com). This product includes software written by Tim
	# Hudson (tjh@cryptsoft.com).

	use strict;

	package TLSProxy::Message;

	use constant TLS_MESSAGE_HEADER_LENGTH => 4;

	#Message types
	use constant {
	MT_HELLO_REQUEST => 0,
	MT_CLIENT_HELLO => 1,
	MT_SERVER_HELLO => 2,
	MT_NEW_SESSION_TICKET => 4,
	MT_CERTIFICATE => 11,
	MT_SERVER_KEY_EXCHANGE => 12,
	MT_CERTIFICATE_REQUEST => 13,
	MT_SERVER_HELLO_DONE => 14,
	MT_CERTIFICATE_VERIFY => 15,
	MT_CLIENT_KEY_EXCHANGE => 16,
	MT_FINISHED => 20,
	MT_CERTIFICATE_STATUS => 22,
	MT_NEXT_PROTO => 67
	};

	#Alert levels
	use constant {
	AL_LEVEL_WARN => 1,
	AL_LEVEL_FATAL => 2
	};

	#Alert descriptions
	use constant {
	AL_DESC_CLOSE_NOTIFY => 0
	};

	my %message_type = (
	MT_HELLO_REQUEST, "HelloRequest",
	MT_CLIENT_HELLO, "ClientHello",
	MT_SERVER_HELLO, "ServerHello",
	MT_NEW_SESSION_TICKET, "NewSessionTicket",
	MT_CERTIFICATE, "Certificate",
	MT_SERVER_KEY_EXCHANGE, "ServerKeyExchange",
	MT_CERTIFICATE_REQUEST, "CertificateRequest",
	MT_SERVER_HELLO_DONE, "ServerHelloDone",
	MT_CERTIFICATE_VERIFY, "CertificateVerify",
	MT_CLIENT_KEY_EXCHANGE, "ClientKeyExchange",
	MT_FINISHED, "Finished",
	MT_CERTIFICATE_STATUS, "CertificateStatus",
	MT_NEXT_PROTO, "NextProto"
	);

	my $payload = "";
	my $messlen = -1;
	my $mt;
	my $startoffset = -1;
	my $server = 0;
	my $success = 0;
	my $end = 0;
	my @message_rec_list = ();
	my @message_frag_lens = ();
	my $ciphersuite = 0;

	sub clear
	{
	$payload = "";
	$messlen = -1;
	$startoffset = -1;
	$server = 0;
	$success = 0;
	$end = 0;
	@message_rec_list = ();
	@message_frag_lens = ();
	}

	#Class method to extract messages from a record
	sub get_messages
	{
	my $class = shift;
	my $serverin = shift;
	my $record = shift;
	my @messages = ();
	my $message;

	@message_frag_lens = ();

	if ($serverin != $server && length($payload) != 0) {
	die "Changed peer, but we still have fragment data\n";
	}
	$server = $serverin;

	if ($record->content_type == TLSProxy::Record::RT_CCS) {
	if ($payload ne "") {
	#We can't handle this yet
	die "CCS received before message data complete\n";
	}
	if ($server) {
	TLSProxy::Record->server_ccs_seen(1);
	} else {
	TLSProxy::Record->client_ccs_seen(1);
	}
	} elsif ($record->content_type == TLSProxy::Record::RT_HANDSHAKE) {
	if ($record->len == 0 \|\| $record->len_real == 0) {
	print " Message truncated\n";
	} else {
	my $recoffset = 0;

	if (length $payload > 0) {
	#We are continuing processing a message started in a previous
	#record. Add this record to the list associated with this
	#message
	push @message_rec_list, $record;

	if ($messlen <= length($payload)) {
	#Shouldn't happen
	die "Internal error: invalid messlen: ".$messlen
	." payload length:".length($payload)."\n";
	}
	if (length($payload) + $record->decrypt_len >= $messlen) {
	#We can complete the message with this record
	$recoffset = $messlen - length($payload);
	$payload .= substr($record->decrypt_data, 0, $recoffset);
	push @message_frag_lens, $recoffset;
	$message = create_message($server, $mt, $payload,
	$startoffset);
	push @messages, $message;

	$payload = "";
	} else {
	#This is just part of the total message
	$payload .= $record->decrypt_data;
	$recoffset = $record->decrypt_len;
	push @message_frag_lens, $record->decrypt_len;
	}
	print " Partial message data read: ".$recoffset." bytes\n";
	}

	while ($record->decrypt_len > $recoffset) {
	#We are at the start of a new message
	if ($record->decrypt_len - $recoffset < 4) {
	#Whilst technically probably valid we can't cope with this
	die "End of record in the middle of a message header\n";
	}
	@message_rec_list = ($record);
	my $lenhi;
	my $lenlo;
	($mt, $lenhi, $lenlo) = unpack('CnC',
	substr($record->decrypt_data,
	$recoffset));
	$messlen = ($lenhi << 8) \| $lenlo;
	print " Message type: $message_type{$mt}\n";
	print " Message Length: $messlen\n";
	$startoffset = $recoffset;
	$recoffset += 4;
	$payload = "";

	if ($recoffset < $record->decrypt_len) {
	#Some payload data is present in this record
	if ($record->decrypt_len - $recoffset >= $messlen) {
	#We can complete the message with this record
	$payload .= substr($record->decrypt_data, $recoffset,
	$messlen);
	$recoffset += $messlen;
	push @message_frag_lens, $messlen;
	$message = create_message($server, $mt, $payload,
	$startoffset);
	push @messages, $message;

	$payload = "";
	} else {
	#This is just part of the total message
	$payload .= substr($record->decrypt_data, $recoffset,
	$record->decrypt_len - $recoffset);
	$recoffset = $record->decrypt_len;
	push @message_frag_lens, $recoffset;
	}
	}
	}
	}
	} elsif ($record->content_type == TLSProxy::Record::RT_APPLICATION_DATA) {
	print " [ENCRYPTED APPLICATION DATA]\n";
	print " [".$record->decrypt_data."]\n";
	} elsif ($record->content_type == TLSProxy::Record::RT_ALERT) {
	my ($alertlev, $alertdesc) = unpack('CC', $record->decrypt_data);
	#All alerts end the test
	$end = 1;
	#A CloseNotify from the client indicates we have finished successfully
	#(we assume)
	if (!$server && $alertlev == AL_LEVEL_WARN
	&& $alertdesc == AL_DESC_CLOSE_NOTIFY) {
	$success = 1;
	}
	}

	return @messages;
	}

	#Function to work out which sub-class we need to create and then
	#construct it
	sub create_message
	{
	my ($server, $mt, $data, $startoffset) = @_;
	my $message;

	#We only support ClientHello in this version...needs to be extended for
	#others
	if ($mt == MT_CLIENT_HELLO) {
	$message = TLSProxy::ClientHello->new(
	$server,
	$data,
	[@message_rec_list],
	$startoffset,
	[@message_frag_lens]
	);
	$message->parse();
	} elsif ($mt == MT_SERVER_HELLO) {
	$message = TLSProxy::ServerHello->new(
	$server,
	$data,
	[@message_rec_list],
	$startoffset,
	[@message_frag_lens]
	);
	$message->parse();
	} elsif ($mt == MT_SERVER_KEY_EXCHANGE) {
	$message = TLSProxy::ServerKeyExchange->new(
	$server,
	$data,
	[@message_rec_list],
	$startoffset,
	[@message_frag_lens]
	);
	$message->parse();
	} elsif ($mt == MT_NEW_SESSION_TICKET) {
	$message = TLSProxy::NewSessionTicket->new(
	$server,
	$data,
	[@message_rec_list],
	$startoffset,
	[@message_frag_lens]
	);
	$message->parse();
	} else {
	#Unknown message type
	$message = TLSProxy::Message->new(
	$server,
	$mt,
	$data,
	[@message_rec_list],
	$startoffset,
	[@message_frag_lens]
	);
	}

	return $message;
	}

	sub end
	{
	my $class = shift;
	return $end;
	}
	sub success
	{
	my $class = shift;
	return $success;
	}
	sub fail
	{
	my $class = shift;
	return !$success && $end;
	}
	sub new
	{
	my $class = shift;
	my ($server,
	$mt,
	$data,
	$records,
	$startoffset,
	$message_frag_lens) = @_;

	my $self = {
	server => $server,
	data => $data,
	records => $records,
	mt => $mt,
	startoffset => $startoffset,
	message_frag_lens => $message_frag_lens
	};

	return bless $self, $class;
	}

	sub ciphersuite
	{
	my $class = shift;
	if (@_) {
	$ciphersuite = shift;
	}
	return $ciphersuite;
	}

	#Update all the underlying records with the modified data from this message
	#Note: Does not currently support re-encrypting
	sub repack
	{
	my $self = shift;
	my $msgdata;

	my $numrecs = $#{$self->records};

	$self->set_message_contents();

	my $lenhi;
	my $lenlo;

	$lenlo = length($self->data) & 0xff;
	$lenhi = length($self->data) >> 8;
	$msgdata = pack('CnC', $self->mt, $lenhi, $lenlo).$self->data;

	if ($numrecs == 0) {
	#The message is fully contained within one record
	my ($rec) = @{$self->records};
	my $recdata = $rec->decrypt_data;

	my $old_length;

	# We use empty message_frag_lens to indicates that pre-repacking,
	# the message wasn't present. The first fragment length doesn't include
	# the TLS header, so we need to check and compute the right length.
	if (@{$self->message_frag_lens}) {
	$old_length = ${$self->message_frag_lens}[0] +
	TLS_MESSAGE_HEADER_LENGTH;
	} else {
	$old_length = 0;
	}

	my $prefix = substr($recdata, 0, $self->startoffset);
	my $suffix = substr($recdata, $self->startoffset + $old_length);

	$rec->decrypt_data($prefix.($msgdata).($suffix));
	# TODO(openssl-team): don't keep explicit lengths.
	# (If a length override is ever needed to construct invalid packets,
	# use an explicit override field instead.)
	$rec->decrypt_len(length($rec->decrypt_data));
	$rec->len($rec->len + length($msgdata) - $old_length);
	# Don't support re-encryption.
	$rec->data($rec->decrypt_data);

	#Update the fragment len in case we changed it above
	${$self->message_frag_lens}[0] = length($msgdata)
	- TLS_MESSAGE_HEADER_LENGTH;
	return;
	}

	#Note we don't currently support changing a fragmented message length
	my $recctr = 0;
	my $datadone = 0;
	foreach my $rec (@{$self->records}) {
	my $recdata = $rec->decrypt_data;
	if ($recctr == 0) {
	#This is the first record
	my $remainlen = length($recdata) - $self->startoffset;
	$rec->data(substr($recdata, 0, $self->startoffset)
	.substr(($msgdata), 0, $remainlen));
	$datadone += $remainlen;
	} elsif ($recctr + 1 == $numrecs) {
	#This is the last record
	$rec->data(substr($msgdata, $datadone));
	} else {
	#This is a middle record
	$rec->data(substr($msgdata, $datadone, length($rec->data)));
	$datadone += length($rec->data);
	}
	$recctr++;
	}
	}

	#To be overridden by sub-classes
	sub set_message_contents
	{
	}

	#Read only accessors
	sub server
	{
	my $self = shift;
	return $self->{server};
	}

	#Read/write accessors
	sub mt
	{
	my $self = shift;
	if (@_) {
	$self->{mt} = shift;
	}
	return $self->{mt};
	}
	sub data
	{
	my $self = shift;
	if (@_) {
	$self->{data} = shift;
	}
	return $self->{data};
	}
	sub records
	{
	my $self = shift;
	if (@_) {
	$self->{records} = shift;
	}
	return $self->{records};
	}
	sub startoffset
	{
	my $self = shift;
	if (@_) {
	$self->{startoffset} = shift;
	}
	return $self->{startoffset};
	}
	sub message_frag_lens
	{
	my $self = shift;
	if (@_) {
	$self->{message_frag_lens} = shift;
	}
	return $self->{message_frag_lens};
	}
	sub encoded_length
	{
	my $self = shift;
	return TLS_MESSAGE_HEADER_LENGTH + length($self->data);
	}

	1;