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1# Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved.
2#
3# Licensed under the Apache License 2.0 (the "License").  You may not use
4# this file except in compliance with the License.  You can obtain a copy
5# in the file LICENSE in the source distribution or at
6# https://www.openssl.org/source/license.html
7
8use strict;
9
10package TLSProxy::Message;
11
12use TLSProxy::Alert;
13
14use constant TLS_MESSAGE_HEADER_LENGTH => 4;
15
16#Message types
17use constant {
18    MT_HELLO_REQUEST => 0,
19    MT_CLIENT_HELLO => 1,
20    MT_SERVER_HELLO => 2,
21    MT_NEW_SESSION_TICKET => 4,
22    MT_ENCRYPTED_EXTENSIONS => 8,
23    MT_CERTIFICATE => 11,
24    MT_SERVER_KEY_EXCHANGE => 12,
25    MT_CERTIFICATE_REQUEST => 13,
26    MT_SERVER_HELLO_DONE => 14,
27    MT_CERTIFICATE_VERIFY => 15,
28    MT_CLIENT_KEY_EXCHANGE => 16,
29    MT_FINISHED => 20,
30    MT_CERTIFICATE_STATUS => 22,
31    MT_NEXT_PROTO => 67
32};
33
34#Alert levels
35use constant {
36    AL_LEVEL_WARN => 1,
37    AL_LEVEL_FATAL => 2
38};
39
40#Alert descriptions
41use constant {
42    AL_DESC_CLOSE_NOTIFY => 0,
43    AL_DESC_UNEXPECTED_MESSAGE => 10,
44    AL_DESC_ILLEGAL_PARAMETER => 47,
45    AL_DESC_NO_RENEGOTIATION => 100
46};
47
48my %message_type = (
49    MT_HELLO_REQUEST, "HelloRequest",
50    MT_CLIENT_HELLO, "ClientHello",
51    MT_SERVER_HELLO, "ServerHello",
52    MT_NEW_SESSION_TICKET, "NewSessionTicket",
53    MT_ENCRYPTED_EXTENSIONS, "EncryptedExtensions",
54    MT_CERTIFICATE, "Certificate",
55    MT_SERVER_KEY_EXCHANGE, "ServerKeyExchange",
56    MT_CERTIFICATE_REQUEST, "CertificateRequest",
57    MT_SERVER_HELLO_DONE, "ServerHelloDone",
58    MT_CERTIFICATE_VERIFY, "CertificateVerify",
59    MT_CLIENT_KEY_EXCHANGE, "ClientKeyExchange",
60    MT_FINISHED, "Finished",
61    MT_CERTIFICATE_STATUS, "CertificateStatus",
62    MT_NEXT_PROTO, "NextProto"
63);
64
65use constant {
66    EXT_SERVER_NAME => 0,
67    EXT_MAX_FRAGMENT_LENGTH => 1,
68    EXT_STATUS_REQUEST => 5,
69    EXT_SUPPORTED_GROUPS => 10,
70    EXT_EC_POINT_FORMATS => 11,
71    EXT_SRP => 12,
72    EXT_SIG_ALGS => 13,
73    EXT_USE_SRTP => 14,
74    EXT_ALPN => 16,
75    EXT_SCT => 18,
76    EXT_PADDING => 21,
77    EXT_ENCRYPT_THEN_MAC => 22,
78    EXT_EXTENDED_MASTER_SECRET => 23,
79    EXT_SESSION_TICKET => 35,
80    EXT_KEY_SHARE => 51,
81    EXT_PSK => 41,
82    EXT_SUPPORTED_VERSIONS => 43,
83    EXT_COOKIE => 44,
84    EXT_PSK_KEX_MODES => 45,
85    EXT_POST_HANDSHAKE_AUTH => 49,
86    EXT_SIG_ALGS_CERT => 50,
87    EXT_RENEGOTIATE => 65281,
88    EXT_NPN => 13172,
89    EXT_CRYPTOPRO_BUG_EXTENSION => 0xfde8,
90    EXT_UNKNOWN => 0xfffe,
91    #Unknown extension that should appear last
92    EXT_FORCE_LAST => 0xffff
93};
94
95# SignatureScheme of TLS 1.3 from:
96# https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-signaturescheme
97# We have to manually grab the SHA224 equivalents from the old registry
98use constant {
99    SIG_ALG_RSA_PKCS1_SHA256 => 0x0401,
100    SIG_ALG_RSA_PKCS1_SHA384 => 0x0501,
101    SIG_ALG_RSA_PKCS1_SHA512 => 0x0601,
102    SIG_ALG_ECDSA_SECP256R1_SHA256 => 0x0403,
103    SIG_ALG_ECDSA_SECP384R1_SHA384 => 0x0503,
104    SIG_ALG_ECDSA_SECP521R1_SHA512 => 0x0603,
105    SIG_ALG_RSA_PSS_RSAE_SHA256 => 0x0804,
106    SIG_ALG_RSA_PSS_RSAE_SHA384 => 0x0805,
107    SIG_ALG_RSA_PSS_RSAE_SHA512 => 0x0806,
108    SIG_ALG_ED25519 => 0x0807,
109    SIG_ALG_ED448 => 0x0808,
110    SIG_ALG_RSA_PSS_PSS_SHA256 => 0x0809,
111    SIG_ALG_RSA_PSS_PSS_SHA384 => 0x080a,
112    SIG_ALG_RSA_PSS_PSS_SHA512 => 0x080b,
113    SIG_ALG_RSA_PKCS1_SHA1 => 0x0201,
114    SIG_ALG_ECDSA_SHA1 => 0x0203,
115    SIG_ALG_DSA_SHA1 => 0x0202,
116    SIG_ALG_DSA_SHA256 => 0x0402,
117    SIG_ALG_DSA_SHA384 => 0x0502,
118    SIG_ALG_DSA_SHA512 => 0x0602,
119    OSSL_SIG_ALG_RSA_PKCS1_SHA224 => 0x0301,
120    OSSL_SIG_ALG_DSA_SHA224 => 0x0302,
121    OSSL_SIG_ALG_ECDSA_SHA224 => 0x0303
122};
123
124use constant {
125    CIPHER_RSA_WITH_AES_128_CBC_SHA => 0x002f,
126    CIPHER_DHE_RSA_AES_128_SHA => 0x0033,
127    CIPHER_ADH_AES_128_SHA => 0x0034,
128    CIPHER_TLS13_AES_128_GCM_SHA256 => 0x1301,
129    CIPHER_TLS13_AES_256_GCM_SHA384 => 0x1302
130};
131
132use constant {
133    CLIENT => 0,
134    SERVER => 1
135};
136
137my $payload = "";
138my $messlen = -1;
139my $mt;
140my $startoffset = -1;
141my $server = 0;
142my $success = 0;
143my $end = 0;
144my @message_rec_list = ();
145my @message_frag_lens = ();
146my $ciphersuite = 0;
147my $successondata = 0;
148my $alert;
149
150sub clear
151{
152    $payload = "";
153    $messlen = -1;
154    $startoffset = -1;
155    $server = 0;
156    $success = 0;
157    $end = 0;
158    $successondata = 0;
159    @message_rec_list = ();
160    @message_frag_lens = ();
161    $alert = undef;
162}
163
164#Class method to extract messages from a record
165sub get_messages
166{
167    my $class = shift;
168    my $serverin = shift;
169    my $record = shift;
170    my @messages = ();
171    my $message;
172
173    @message_frag_lens = ();
174
175    if ($serverin != $server && length($payload) != 0) {
176        die "Changed peer, but we still have fragment data\n";
177    }
178    $server = $serverin;
179
180    if ($record->content_type == TLSProxy::Record::RT_CCS) {
181        if ($payload ne "") {
182            #We can't handle this yet
183            die "CCS received before message data complete\n";
184        }
185        if (!TLSProxy::Proxy->is_tls13()) {
186            if ($server) {
187                TLSProxy::Record->server_encrypting(1);
188            } else {
189                TLSProxy::Record->client_encrypting(1);
190            }
191        }
192    } elsif ($record->content_type == TLSProxy::Record::RT_HANDSHAKE) {
193        if ($record->len == 0 || $record->len_real == 0) {
194            print "  Message truncated\n";
195        } else {
196            my $recoffset = 0;
197
198            if (length $payload > 0) {
199                #We are continuing processing a message started in a previous
200                #record. Add this record to the list associated with this
201                #message
202                push @message_rec_list, $record;
203
204                if ($messlen <= length($payload)) {
205                    #Shouldn't happen
206                    die "Internal error: invalid messlen: ".$messlen
207                        ." payload length:".length($payload)."\n";
208                }
209                if (length($payload) + $record->decrypt_len >= $messlen) {
210                    #We can complete the message with this record
211                    $recoffset = $messlen - length($payload);
212                    $payload .= substr($record->decrypt_data, 0, $recoffset);
213                    push @message_frag_lens, $recoffset;
214                    $message = create_message($server, $mt, $payload,
215                                              $startoffset);
216                    push @messages, $message;
217
218                    $payload = "";
219                } else {
220                    #This is just part of the total message
221                    $payload .= $record->decrypt_data;
222                    $recoffset = $record->decrypt_len;
223                    push @message_frag_lens, $record->decrypt_len;
224                }
225                print "  Partial message data read: ".$recoffset." bytes\n";
226            }
227
228            while ($record->decrypt_len > $recoffset) {
229                #We are at the start of a new message
230                if ($record->decrypt_len - $recoffset < 4) {
231                    #Whilst technically probably valid we can't cope with this
232                    die "End of record in the middle of a message header\n";
233                }
234                @message_rec_list = ($record);
235                my $lenhi;
236                my $lenlo;
237                ($mt, $lenhi, $lenlo) = unpack('CnC',
238                                               substr($record->decrypt_data,
239                                                      $recoffset));
240                $messlen = ($lenhi << 8) | $lenlo;
241                print "  Message type: $message_type{$mt}\n";
242                print "  Message Length: $messlen\n";
243                $startoffset = $recoffset;
244                $recoffset += 4;
245                $payload = "";
246
247                if ($recoffset <= $record->decrypt_len) {
248                    #Some payload data is present in this record
249                    if ($record->decrypt_len - $recoffset >= $messlen) {
250                        #We can complete the message with this record
251                        $payload .= substr($record->decrypt_data, $recoffset,
252                                           $messlen);
253                        $recoffset += $messlen;
254                        push @message_frag_lens, $messlen;
255                        $message = create_message($server, $mt, $payload,
256                                                  $startoffset);
257                        push @messages, $message;
258
259                        $payload = "";
260                    } else {
261                        #This is just part of the total message
262                        $payload .= substr($record->decrypt_data, $recoffset,
263                                           $record->decrypt_len - $recoffset);
264                        $recoffset = $record->decrypt_len;
265                        push @message_frag_lens, $recoffset;
266                    }
267                }
268            }
269        }
270    } elsif ($record->content_type == TLSProxy::Record::RT_APPLICATION_DATA) {
271        print "  [ENCRYPTED APPLICATION DATA]\n";
272        print "  [".$record->decrypt_data."]\n";
273
274        if ($successondata) {
275            $success = 1;
276            $end = 1;
277        }
278    } elsif ($record->content_type == TLSProxy::Record::RT_ALERT) {
279        my ($alertlev, $alertdesc) = unpack('CC', $record->decrypt_data);
280        print "  [$alertlev, $alertdesc]\n";
281        #A CloseNotify from the client indicates we have finished successfully
282        #(we assume)
283        if (!$end && !$server && $alertlev == AL_LEVEL_WARN
284            && $alertdesc == AL_DESC_CLOSE_NOTIFY) {
285            $success = 1;
286        }
287        #Fatal or close notify alerts end the test
288        if ($alertlev == AL_LEVEL_FATAL || $alertdesc == AL_DESC_CLOSE_NOTIFY) {
289            $end = 1;
290        }
291        $alert = TLSProxy::Alert->new(
292            $server,
293            $record->encrypted,
294            $alertlev,
295            $alertdesc);
296    }
297
298    return @messages;
299}
300
301#Function to work out which sub-class we need to create and then
302#construct it
303sub create_message
304{
305    my ($server, $mt, $data, $startoffset) = @_;
306    my $message;
307
308    #We only support ClientHello in this version...needs to be extended for
309    #others
310    if ($mt == MT_CLIENT_HELLO) {
311        $message = TLSProxy::ClientHello->new(
312            $server,
313            $data,
314            [@message_rec_list],
315            $startoffset,
316            [@message_frag_lens]
317        );
318        $message->parse();
319    } elsif ($mt == MT_SERVER_HELLO) {
320        $message = TLSProxy::ServerHello->new(
321            $server,
322            $data,
323            [@message_rec_list],
324            $startoffset,
325            [@message_frag_lens]
326        );
327        $message->parse();
328    } elsif ($mt == MT_ENCRYPTED_EXTENSIONS) {
329        $message = TLSProxy::EncryptedExtensions->new(
330            $server,
331            $data,
332            [@message_rec_list],
333            $startoffset,
334            [@message_frag_lens]
335        );
336        $message->parse();
337    } elsif ($mt == MT_CERTIFICATE) {
338        $message = TLSProxy::Certificate->new(
339            $server,
340            $data,
341            [@message_rec_list],
342            $startoffset,
343            [@message_frag_lens]
344        );
345        $message->parse();
346    } elsif ($mt == MT_CERTIFICATE_REQUEST) {
347        $message = TLSProxy::CertificateRequest->new(
348            $server,
349            $data,
350            [@message_rec_list],
351            $startoffset,
352            [@message_frag_lens]
353        );
354        $message->parse();
355    } elsif ($mt == MT_CERTIFICATE_VERIFY) {
356        $message = TLSProxy::CertificateVerify->new(
357            $server,
358            $data,
359            [@message_rec_list],
360            $startoffset,
361            [@message_frag_lens]
362        );
363        $message->parse();
364    } elsif ($mt == MT_SERVER_KEY_EXCHANGE) {
365        $message = TLSProxy::ServerKeyExchange->new(
366            $server,
367            $data,
368            [@message_rec_list],
369            $startoffset,
370            [@message_frag_lens]
371        );
372        $message->parse();
373    } elsif ($mt == MT_NEW_SESSION_TICKET) {
374        $message = TLSProxy::NewSessionTicket->new(
375            $server,
376            $data,
377            [@message_rec_list],
378            $startoffset,
379            [@message_frag_lens]
380        );
381        $message->parse();
382    } else {
383        #Unknown message type
384        $message = TLSProxy::Message->new(
385            $server,
386            $mt,
387            $data,
388            [@message_rec_list],
389            $startoffset,
390            [@message_frag_lens]
391        );
392    }
393
394    return $message;
395}
396
397sub end
398{
399    my $class = shift;
400    return $end;
401}
402sub success
403{
404    my $class = shift;
405    return $success;
406}
407sub fail
408{
409    my $class = shift;
410    return !$success && $end;
411}
412
413sub alert
414{
415    return $alert;
416}
417
418sub new
419{
420    my $class = shift;
421    my ($server,
422        $mt,
423        $data,
424        $records,
425        $startoffset,
426        $message_frag_lens) = @_;
427
428    my $self = {
429        server => $server,
430        data => $data,
431        records => $records,
432        mt => $mt,
433        startoffset => $startoffset,
434        message_frag_lens => $message_frag_lens,
435        dupext => -1
436    };
437
438    return bless $self, $class;
439}
440
441sub ciphersuite
442{
443    my $class = shift;
444    if (@_) {
445      $ciphersuite = shift;
446    }
447    return $ciphersuite;
448}
449
450#Update all the underlying records with the modified data from this message
451#Note: Only supports TLSv1.3 and ETM encryption
452sub repack
453{
454    my $self = shift;
455    my $msgdata;
456
457    my $numrecs = $#{$self->records};
458
459    $self->set_message_contents();
460
461    my $lenhi;
462    my $lenlo;
463
464    $lenlo = length($self->data) & 0xff;
465    $lenhi = length($self->data) >> 8;
466    $msgdata = pack('CnC', $self->mt, $lenhi, $lenlo).$self->data;
467
468    if ($numrecs == 0) {
469        #The message is fully contained within one record
470        my ($rec) = @{$self->records};
471        my $recdata = $rec->decrypt_data;
472
473        my $old_length;
474
475        # We use empty message_frag_lens to indicates that pre-repacking,
476        # the message wasn't present. The first fragment length doesn't include
477        # the TLS header, so we need to check and compute the right length.
478        if (@{$self->message_frag_lens}) {
479            $old_length = ${$self->message_frag_lens}[0] +
480              TLS_MESSAGE_HEADER_LENGTH;
481        } else {
482            $old_length = 0;
483        }
484
485        my $prefix = substr($recdata, 0, $self->startoffset);
486        my $suffix = substr($recdata, $self->startoffset + $old_length);
487
488        $rec->decrypt_data($prefix.($msgdata).($suffix));
489        # TODO(openssl-team): don't keep explicit lengths.
490        # (If a length override is ever needed to construct invalid packets,
491        #  use an explicit override field instead.)
492        $rec->decrypt_len(length($rec->decrypt_data));
493        # Only support re-encryption for TLSv1.3 and ETM.
494        if ($rec->encrypted()) {
495            if (TLSProxy::Proxy->is_tls13()) {
496                #Add content type (1 byte) and 16 tag bytes
497                $rec->data($rec->decrypt_data
498                    .pack("C", TLSProxy::Record::RT_HANDSHAKE).("\0"x16));
499            } elsif ($rec->etm()) {
500                my $data = $rec->decrypt_data;
501                #Add padding
502                my $padval = length($data) % 16;
503                $padval = 15 - $padval;
504                for (0..$padval) {
505                    $data .= pack("C", $padval);
506                }
507
508                #Add MAC. Assumed to be 20 bytes
509                foreach my $macval (0..19) {
510                    $data .= pack("C", $macval);
511                }
512
513                if ($rec->version() >= TLSProxy::Record::VERS_TLS_1_1) {
514                    #Explicit IV
515                    $data = ("\0"x16).$data;
516                }
517                $rec->data($data);
518            } else {
519                die "Unsupported encryption: No ETM";
520            }
521        } else {
522            $rec->data($rec->decrypt_data);
523        }
524        $rec->len(length($rec->data));
525
526        #Update the fragment len in case we changed it above
527        ${$self->message_frag_lens}[0] = length($msgdata)
528                                         - TLS_MESSAGE_HEADER_LENGTH;
529        return;
530    }
531
532    #Note we don't currently support changing a fragmented message length
533    my $recctr = 0;
534    my $datadone = 0;
535    foreach my $rec (@{$self->records}) {
536        my $recdata = $rec->decrypt_data;
537        if ($recctr == 0) {
538            #This is the first record
539            my $remainlen = length($recdata) - $self->startoffset;
540            $rec->data(substr($recdata, 0, $self->startoffset)
541                       .substr(($msgdata), 0, $remainlen));
542            $datadone += $remainlen;
543        } elsif ($recctr + 1 == $numrecs) {
544            #This is the last record
545            $rec->data(substr($msgdata, $datadone));
546        } else {
547            #This is a middle record
548            $rec->data(substr($msgdata, $datadone, length($rec->data)));
549            $datadone += length($rec->data);
550        }
551        $recctr++;
552    }
553}
554
555#To be overridden by sub-classes
556sub set_message_contents
557{
558}
559
560#Read only accessors
561sub server
562{
563    my $self = shift;
564    return $self->{server};
565}
566
567#Read/write accessors
568sub mt
569{
570    my $self = shift;
571    if (@_) {
572      $self->{mt} = shift;
573    }
574    return $self->{mt};
575}
576sub data
577{
578    my $self = shift;
579    if (@_) {
580      $self->{data} = shift;
581    }
582    return $self->{data};
583}
584sub records
585{
586    my $self = shift;
587    if (@_) {
588      $self->{records} = shift;
589    }
590    return $self->{records};
591}
592sub startoffset
593{
594    my $self = shift;
595    if (@_) {
596      $self->{startoffset} = shift;
597    }
598    return $self->{startoffset};
599}
600sub message_frag_lens
601{
602    my $self = shift;
603    if (@_) {
604      $self->{message_frag_lens} = shift;
605    }
606    return $self->{message_frag_lens};
607}
608sub encoded_length
609{
610    my $self = shift;
611    return TLS_MESSAGE_HEADER_LENGTH + length($self->data);
612}
613sub dupext
614{
615    my $self = shift;
616    if (@_) {
617        $self->{dupext} = shift;
618    }
619    return $self->{dupext};
620}
621sub successondata
622{
623    my $class = shift;
624    if (@_) {
625        $successondata = shift;
626    }
627    return $successondata;
628}
6291;
630