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[openssl.git] / ssl / s3_pkt.c
1 /* ssl/s3_pkt.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young (eay@cryptsoft.com).
7  * The implementation was written so as to conform with Netscapes SSL.
8  * 
9  * This library is free for commercial and non-commercial use as long as
10  * the following conditions are aheared to.  The following conditions
11  * apply to all code found in this distribution, be it the RC4, RSA,
12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13  * included with this distribution is covered by the same copyright terms
14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15  * 
16  * Copyright remains Eric Young's, and as such any Copyright notices in
17  * the code are not to be removed.
18  * If this package is used in a product, Eric Young should be given attribution
19  * as the author of the parts of the library used.
20  * This can be in the form of a textual message at program startup or
21  * in documentation (online or textual) provided with the package.
22  * 
23  * Redistribution and use in source and binary forms, with or without
24  * modification, are permitted provided that the following conditions
25  * are met:
26  * 1. Redistributions of source code must retain the copyright
27  *    notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  *    notice, this list of conditions and the following disclaimer in the
30  *    documentation and/or other materials provided with the distribution.
31  * 3. All advertising materials mentioning features or use of this software
32  *    must display the following acknowledgement:
33  *    "This product includes cryptographic software written by
34  *     Eric Young (eay@cryptsoft.com)"
35  *    The word 'cryptographic' can be left out if the rouines from the library
36  *    being used are not cryptographic related :-).
37  * 4. If you include any Windows specific code (or a derivative thereof) from 
38  *    the apps directory (application code) you must include an acknowledgement:
39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40  * 
41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51  * SUCH DAMAGE.
52  * 
53  * The licence and distribution terms for any publically available version or
54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
55  * copied and put under another distribution licence
56  * [including the GNU Public Licence.]
57  */
58 /* ====================================================================
59  * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
60  *
61  * Redistribution and use in source and binary forms, with or without
62  * modification, are permitted provided that the following conditions
63  * are met:
64  *
65  * 1. Redistributions of source code must retain the above copyright
66  *    notice, this list of conditions and the following disclaimer. 
67  *
68  * 2. Redistributions in binary form must reproduce the above copyright
69  *    notice, this list of conditions and the following disclaimer in
70  *    the documentation and/or other materials provided with the
71  *    distribution.
72  *
73  * 3. All advertising materials mentioning features or use of this
74  *    software must display the following acknowledgment:
75  *    "This product includes software developed by the OpenSSL Project
76  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
77  *
78  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
79  *    endorse or promote products derived from this software without
80  *    prior written permission. For written permission, please contact
81  *    openssl-core@openssl.org.
82  *
83  * 5. Products derived from this software may not be called "OpenSSL"
84  *    nor may "OpenSSL" appear in their names without prior written
85  *    permission of the OpenSSL Project.
86  *
87  * 6. Redistributions of any form whatsoever must retain the following
88  *    acknowledgment:
89  *    "This product includes software developed by the OpenSSL Project
90  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
91  *
92  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
93  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
94  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
95  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
96  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
97  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
98  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
99  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
100  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
101  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
102  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
103  * OF THE POSSIBILITY OF SUCH DAMAGE.
104  * ====================================================================
105  *
106  * This product includes cryptographic software written by Eric Young
107  * (eay@cryptsoft.com).  This product includes software written by Tim
108  * Hudson (tjh@cryptsoft.com).
109  *
110  */
111
112 #include <stdio.h>
113 #include <errno.h>
114 #define USE_SOCKETS
115 #include "ssl_locl.h"
116 #include <openssl/evp.h>
117 #include <openssl/buffer.h>
118 #include <openssl/rand.h>
119
120 #ifndef  EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK
121 # define EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK 0
122 #endif
123
124 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
125                          unsigned int len, int create_empty_fragment);
126 static int ssl3_get_record(SSL *s);
127
128 int ssl3_read_n(SSL *s, int n, int max, int extend)
129         {
130         /* If extend == 0, obtain new n-byte packet; if extend == 1, increase
131          * packet by another n bytes.
132          * The packet will be in the sub-array of s->s3->rbuf.buf specified
133          * by s->packet and s->packet_length.
134          * (If s->read_ahead is set, 'max' bytes may be stored in rbuf
135          * [plus s->packet_length bytes if extend == 1].)
136          */
137         int i,len,left;
138         long align=0;
139         unsigned char *pkt;
140         SSL3_BUFFER *rb;
141
142         if (n <= 0) return n;
143
144         rb    = &(s->s3->rbuf);
145         if (rb->buf == NULL)
146                 if (!ssl3_setup_read_buffer(s))
147                         return -1;
148
149         left  = rb->left;
150 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
151         align = (long)rb->buf + SSL3_RT_HEADER_LENGTH;
152         align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
153 #endif
154
155         if (!extend)
156                 {
157                 /* start with empty packet ... */
158                 if (left == 0)
159                         rb->offset = align;
160                 else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH)
161                         {
162                         /* check if next packet length is large
163                          * enough to justify payload alignment... */
164                         pkt = rb->buf + rb->offset;
165                         if (pkt[0] == SSL3_RT_APPLICATION_DATA
166                             && (pkt[3]<<8|pkt[4]) >= 128)
167                                 {
168                                 /* Note that even if packet is corrupted
169                                  * and its length field is insane, we can
170                                  * only be led to wrong decision about
171                                  * whether memmove will occur or not.
172                                  * Header values has no effect on memmove
173                                  * arguments and therefore no buffer
174                                  * overrun can be triggered. */
175                                 memmove (rb->buf+align,pkt,left);
176                                 rb->offset = align;
177                                 }
178                         }
179                 s->packet = rb->buf + rb->offset;
180                 s->packet_length = 0;
181                 /* ... now we can act as if 'extend' was set */
182                 }
183
184         /* For DTLS/UDP reads should not span multiple packets
185          * because the read operation returns the whole packet
186          * at once (as long as it fits into the buffer). */
187         if (SSL_IS_DTLS(s))
188                 {
189                 if (left > 0 && n > left)
190                         n = left;
191                 }
192
193         /* if there is enough in the buffer from a previous read, take some */
194         if (left >= n)
195                 {
196                 s->packet_length+=n;
197                 rb->left=left-n;
198                 rb->offset+=n;
199                 return(n);
200                 }
201
202         /* else we need to read more data */
203
204         len = s->packet_length;
205         pkt = rb->buf+align;
206         /* Move any available bytes to front of buffer:
207          * 'len' bytes already pointed to by 'packet',
208          * 'left' extra ones at the end */
209         if (s->packet != pkt) /* len > 0 */
210                 {
211                 memmove(pkt, s->packet, len+left);
212                 s->packet = pkt;
213                 rb->offset = len + align;
214                 }
215
216         if (n > (int)(rb->len - rb->offset)) /* does not happen */
217                 {
218                 SSLerr(SSL_F_SSL3_READ_N,ERR_R_INTERNAL_ERROR);
219                 return -1;
220                 }
221
222         if (!s->read_ahead)
223                 /* ignore max parameter */
224                 max = n;
225         else
226                 {
227                 if (max < n)
228                         max = n;
229                 if (max > (int)(rb->len - rb->offset))
230                         max = rb->len - rb->offset;
231                 }
232
233         while (left < n)
234                 {
235                 /* Now we have len+left bytes at the front of s->s3->rbuf.buf
236                  * and need to read in more until we have len+n (up to
237                  * len+max if possible) */
238
239                 clear_sys_error();
240                 if (s->rbio != NULL)
241                         {
242                         s->rwstate=SSL_READING;
243                         i=BIO_read(s->rbio,pkt+len+left, max-left);
244                         }
245                 else
246                         {
247                         SSLerr(SSL_F_SSL3_READ_N,SSL_R_READ_BIO_NOT_SET);
248                         i = -1;
249                         }
250
251                 if (i <= 0)
252                         {
253                         rb->left = left;
254                         if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
255                                 !SSL_IS_DTLS(s))
256                                 if (len+left == 0)
257                                         ssl3_release_read_buffer(s);
258                         return(i);
259                         }
260                 left+=i;
261                 /* reads should *never* span multiple packets for DTLS because
262                  * the underlying transport protocol is message oriented as opposed
263                  * to byte oriented as in the TLS case. */
264                 if (SSL_IS_DTLS(s))
265                         {
266                         if (n > left)
267                                 n = left; /* makes the while condition false */
268                         }
269                 }
270
271         /* done reading, now the book-keeping */
272         rb->offset += n;
273         rb->left = left - n;
274         s->packet_length += n;
275         s->rwstate=SSL_NOTHING;
276         return(n);
277         }
278
279 /* MAX_EMPTY_RECORDS defines the number of consecutive, empty records that will
280  * be processed per call to ssl3_get_record. Without this limit an attacker
281  * could send empty records at a faster rate than we can process and cause
282  * ssl3_get_record to loop forever. */
283 #define MAX_EMPTY_RECORDS 32
284
285 /* Call this to get a new input record.
286  * It will return <= 0 if more data is needed, normally due to an error
287  * or non-blocking IO.
288  * When it finishes, one packet has been decoded and can be found in
289  * ssl->s3->rrec.type    - is the type of record
290  * ssl->s3->rrec.data,   - data
291  * ssl->s3->rrec.length, - number of bytes
292  */
293 /* used only by ssl3_read_bytes */
294 static int ssl3_get_record(SSL *s)
295         {
296         int ssl_major,ssl_minor,al;
297         int enc_err,n,i,ret= -1;
298         SSL3_RECORD *rr;
299         SSL_SESSION *sess;
300         unsigned char *p;
301         unsigned char md[EVP_MAX_MD_SIZE];
302         short version;
303         unsigned mac_size;
304         size_t extra;
305         unsigned empty_record_count = 0;
306
307         rr= &(s->s3->rrec);
308         sess=s->session;
309
310         if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
311                 extra=SSL3_RT_MAX_EXTRA;
312         else
313                 extra=0;
314         if (extra && !s->s3->init_extra)
315                 {
316                 /* An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
317                  * set after ssl3_setup_buffers() was done */
318                 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
319                 return -1;
320                 }
321
322 again:
323         /* check if we have the header */
324         if (    (s->rstate != SSL_ST_READ_BODY) ||
325                 (s->packet_length < SSL3_RT_HEADER_LENGTH)) 
326                 {
327                 n=ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
328                 if (n <= 0) return(n); /* error or non-blocking */
329                 s->rstate=SSL_ST_READ_BODY;
330
331                 p=s->packet;
332                 if (s->msg_callback)
333                         s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s, s->msg_callback_arg);
334
335                 /* Pull apart the header into the SSL3_RECORD */
336                 rr->type= *(p++);
337                 ssl_major= *(p++);
338                 ssl_minor= *(p++);
339                 version=(ssl_major<<8)|ssl_minor;
340                 n2s(p,rr->length);
341 #if 0
342 fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length);
343 #endif
344
345                 /* Lets check version */
346                 if (!s->first_packet)
347                         {
348                         if (version != s->version)
349                                 {
350                                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
351                                 if ((s->version & 0xFF00) == (version & 0xFF00) && !s->enc_write_ctx && !s->write_hash)
352                                         /* Send back error using their minor version number :-) */
353                                         s->version = (unsigned short)version;
354                                 al=SSL_AD_PROTOCOL_VERSION;
355                                 goto f_err;
356                                 }
357                         }
358
359                 if ((version>>8) != SSL3_VERSION_MAJOR)
360                         {
361                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
362                         goto err;
363                         }
364
365                 if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH)
366                         {
367                         al=SSL_AD_RECORD_OVERFLOW;
368                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
369                         goto f_err;
370                         }
371
372                 /* now s->rstate == SSL_ST_READ_BODY */
373                 }
374
375         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
376
377         if (rr->length > s->packet_length-SSL3_RT_HEADER_LENGTH)
378                 {
379                 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
380                 i=rr->length;
381                 n=ssl3_read_n(s,i,i,1);
382                 if (n <= 0) return(n); /* error or non-blocking io */
383                 /* now n == rr->length,
384                  * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */
385                 }
386
387         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
388
389         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
390          * and we have that many bytes in s->packet
391          */
392         rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);
393
394         /* ok, we can now read from 's->packet' data into 'rr'
395          * rr->input points at rr->length bytes, which
396          * need to be copied into rr->data by either
397          * the decryption or by the decompression
398          * When the data is 'copied' into the rr->data buffer,
399          * rr->input will be pointed at the new buffer */ 
400
401         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
402          * rr->length bytes of encrypted compressed stuff. */
403
404         /* check is not needed I believe */
405         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
406                 {
407                 al=SSL_AD_RECORD_OVERFLOW;
408                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
409                 goto f_err;
410                 }
411
412         /* decrypt in place in 'rr->input' */
413         rr->data=rr->input;
414         rr->orig_len=rr->length;
415         /* If in encrypt-then-mac mode calculate mac from encrypted record.
416          * All the details below are public so no timing details can leak.
417          */
418         if (SSL_USE_ETM(s) && s->read_hash)
419                 {
420                 unsigned char *mac;
421                 mac_size=EVP_MD_CTX_size(s->read_hash);
422                 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
423                 if (rr->length < mac_size)
424                         {
425                         al=SSL_AD_DECODE_ERROR;
426                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
427                         goto f_err;
428                         }
429                 rr->length -= mac_size;
430                 mac = rr->data + rr->length;
431                 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
432                 if (i < 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
433                         {
434                         al=SSL_AD_BAD_RECORD_MAC;
435                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
436                         goto f_err;
437                         }
438                 }
439
440         enc_err = s->method->ssl3_enc->enc(s,0);
441         /* enc_err is:
442          *    0: (in non-constant time) if the record is publically invalid.
443          *    1: if the padding is valid
444          *    -1: if the padding is invalid */
445         if (enc_err == 0)
446                 {
447                 al=SSL_AD_DECRYPTION_FAILED;
448                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
449                 goto f_err;
450                 }
451
452 #ifdef TLS_DEBUG
453 printf("dec %d\n",rr->length);
454 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
455 printf("\n");
456 #endif
457
458         /* r->length is now the compressed data plus mac */
459         if ((sess != NULL) &&
460             (s->enc_read_ctx != NULL) &&
461             (EVP_MD_CTX_md(s->read_hash) != NULL) && !SSL_USE_ETM(s))
462                 {
463                 /* s->read_hash != NULL => mac_size != -1 */
464                 unsigned char *mac = NULL;
465                 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
466                 mac_size=EVP_MD_CTX_size(s->read_hash);
467                 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
468
469                 /* orig_len is the length of the record before any padding was
470                  * removed. This is public information, as is the MAC in use,
471                  * therefore we can safely process the record in a different
472                  * amount of time if it's too short to possibly contain a MAC.
473                  */
474                 if (rr->orig_len < mac_size ||
475                     /* CBC records must have a padding length byte too. */
476                     (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
477                      rr->orig_len < mac_size+1))
478                         {
479                         al=SSL_AD_DECODE_ERROR;
480                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
481                         goto f_err;
482                         }
483
484                 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
485                         {
486                         /* We update the length so that the TLS header bytes
487                          * can be constructed correctly but we need to extract
488                          * the MAC in constant time from within the record,
489                          * without leaking the contents of the padding bytes.
490                          * */
491                         mac = mac_tmp;
492                         ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
493                         rr->length -= mac_size;
494                         }
495                 else
496                         {
497                         /* In this case there's no padding, so |rec->orig_len|
498                          * equals |rec->length| and we checked that there's
499                          * enough bytes for |mac_size| above. */
500                         rr->length -= mac_size;
501                         mac = &rr->data[rr->length];
502                         }
503
504                 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
505                 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
506                         enc_err = -1;
507                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
508                         enc_err = -1;
509                 }
510
511         if (enc_err < 0)
512                 {
513                 /* A separate 'decryption_failed' alert was introduced with TLS 1.0,
514                  * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
515                  * failure is directly visible from the ciphertext anyway,
516                  * we should not reveal which kind of error occurred -- this
517                  * might become visible to an attacker (e.g. via a logfile) */
518                 al=SSL_AD_BAD_RECORD_MAC;
519                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
520                 goto f_err;
521                 }
522
523         /* r->length is now just compressed */
524         if (s->expand != NULL)
525                 {
526                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
527                         {
528                         al=SSL_AD_RECORD_OVERFLOW;
529                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
530                         goto f_err;
531                         }
532                 if (!ssl3_do_uncompress(s))
533                         {
534                         al=SSL_AD_DECOMPRESSION_FAILURE;
535                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
536                         goto f_err;
537                         }
538                 }
539
540         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH+extra)
541                 {
542                 al=SSL_AD_RECORD_OVERFLOW;
543                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
544                 goto f_err;
545                 }
546
547         rr->off=0;
548         /* So at this point the following is true
549          * ssl->s3->rrec.type   is the type of record
550          * ssl->s3->rrec.length == number of bytes in record
551          * ssl->s3->rrec.off    == offset to first valid byte
552          * ssl->s3->rrec.data   == where to take bytes from, increment
553          *                         after use :-).
554          */
555
556         /* we have pulled in a full packet so zero things */
557         s->packet_length=0;
558
559         /* just read a 0 length packet */
560         if (rr->length == 0)
561                 {
562                 empty_record_count++;
563                 if (empty_record_count > MAX_EMPTY_RECORDS)
564                         {
565                         al=SSL_AD_UNEXPECTED_MESSAGE;
566                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_TOO_MANY_EMPTY_FRAGMENTS);
567                         goto f_err;
568                         }
569                 goto again;
570                 }
571
572 #if 0
573 fprintf(stderr, "Ultimate Record type=%d, Length=%d\n", rr->type, rr->length);
574 #endif
575
576         return(1);
577
578 f_err:
579         ssl3_send_alert(s,SSL3_AL_FATAL,al);
580 err:
581         return(ret);
582         }
583
584 int ssl3_do_uncompress(SSL *ssl)
585         {
586 #ifndef OPENSSL_NO_COMP
587         int i;
588         SSL3_RECORD *rr;
589
590         rr= &(ssl->s3->rrec);
591         i=COMP_expand_block(ssl->expand,rr->comp,
592                 SSL3_RT_MAX_PLAIN_LENGTH,rr->data,(int)rr->length);
593         if (i < 0)
594                 return(0);
595         else
596                 rr->length=i;
597         rr->data=rr->comp;
598 #endif
599         return(1);
600         }
601
602 int ssl3_do_compress(SSL *ssl)
603         {
604 #ifndef OPENSSL_NO_COMP
605         int i;
606         SSL3_RECORD *wr;
607
608         wr= &(ssl->s3->wrec);
609         i=COMP_compress_block(ssl->compress,wr->data,
610                 SSL3_RT_MAX_COMPRESSED_LENGTH,
611                 wr->input,(int)wr->length);
612         if (i < 0)
613                 return(0);
614         else
615                 wr->length=i;
616
617         wr->input=wr->data;
618 #endif
619         return(1);
620         }
621
622 /* Call this to write data in records of type 'type'
623  * It will return <= 0 if not all data has been sent or non-blocking IO.
624  */
625 int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
626         {
627         const unsigned char *buf=buf_;
628         unsigned int tot,n,nw;
629         int i;
630
631         s->rwstate=SSL_NOTHING;
632         tot=s->s3->wnum;
633         s->s3->wnum=0;
634
635         if (SSL_in_init(s) && !s->in_handshake)
636                 {
637                 i=s->handshake_func(s);
638                 if (i < 0) return(i);
639                 if (i == 0)
640                         {
641                         SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
642                         return -1;
643                         }
644                 }
645
646         n=(len-tot);
647         for (;;)
648                 {
649                 if (n > s->max_send_fragment)
650                         nw=s->max_send_fragment;
651                 else
652                         nw=n;
653
654                 i=do_ssl3_write(s, type, &(buf[tot]), nw, 0);
655                 if (i <= 0)
656                         {
657                         s->s3->wnum=tot;
658                         return i;
659                         }
660
661                 if ((i == (int)n) ||
662                         (type == SSL3_RT_APPLICATION_DATA &&
663                          (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
664                         {
665                         /* next chunk of data should get another prepended empty fragment
666                          * in ciphersuites with known-IV weakness: */
667                         s->s3->empty_fragment_done = 0;
668                         
669                         return tot+i;
670                         }
671
672                 n-=i;
673                 tot+=i;
674                 }
675         }
676
677 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
678                          unsigned int len, int create_empty_fragment)
679         {
680         unsigned char *p,*plen;
681         int i,mac_size,clear=0;
682         int prefix_len=0;
683         int eivlen;
684         long align=0;
685         SSL3_RECORD *wr;
686         SSL3_BUFFER *wb=&(s->s3->wbuf);
687         SSL_SESSION *sess;
688
689         if (wb->buf == NULL)
690                 if (!ssl3_setup_write_buffer(s))
691                         return -1;
692
693         /* first check if there is a SSL3_BUFFER still being written
694          * out.  This will happen with non blocking IO */
695         if (wb->left != 0)
696                 return(ssl3_write_pending(s,type,buf,len));
697
698         /* If we have an alert to send, lets send it */
699         if (s->s3->alert_dispatch)
700                 {
701                 i=s->method->ssl_dispatch_alert(s);
702                 if (i <= 0)
703                         return(i);
704                 /* if it went, fall through and send more stuff */
705                 }
706
707         if (len == 0 && !create_empty_fragment)
708                 return 0;
709
710         wr= &(s->s3->wrec);
711         sess=s->session;
712
713         if (    (sess == NULL) ||
714                 (s->enc_write_ctx == NULL) ||
715                 (EVP_MD_CTX_md(s->write_hash) == NULL))
716                 {
717 #if 1
718                 clear=s->enc_write_ctx?0:1;     /* must be AEAD cipher */
719 #else
720                 clear=1;
721 #endif
722                 mac_size=0;
723                 }
724         else
725                 {
726                 mac_size=EVP_MD_CTX_size(s->write_hash);
727                 if (mac_size < 0)
728                         goto err;
729                 }
730
731 #if !defined(OPENSSL_NO_MULTIBLOCK) && EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK
732         if (type==SSL3_RT_APPLICATION_DATA && s->compress==NULL &&
733             !SSL_USE_ETM(s) && SSL_USE_EXPLICIT_IV(s) && /*!SSL_IS_DTLS(s) &&*/
734             EVP_CIPHER_flags(s->enc_write_ctx->cipher)&EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK)
735                 do {
736                 unsigned char aad[13];
737                 EVP_CTRL_TLS1_1_MULTIBLOCK_PARAM mb_param = {NULL,aad,sizeof(aad),0};
738                 int packlen;
739
740                 memcpy(aad,s->s3->write_sequence,8);
741                 aad[8]=type;
742                 aad[9]=(unsigned char)(s->version>>8);
743                 aad[10]=(unsigned char)(s->version);
744                 aad[11]=(unsigned char)(len>>8);
745                 aad[12]=(unsigned char)len;
746                 packlen = EVP_CIPHER_CTX_ctrl(s->enc_write_ctx,
747                                 EVP_CTRL_TLS1_1_MULTIBLOCK_AAD,
748                                 sizeof(mb_param),&mb_param);
749
750                 if (packlen==0 || packlen > wb->len) break;
751
752                 mb_param.out = wb->buf;
753                 mb_param.inp = buf;
754                 mb_param.len = len;
755                 EVP_CIPHER_CTX_ctrl(s->enc_write_ctx,
756                                 EVP_CTRL_TLS1_1_MULTIBLOCK_ENCRYPT,
757                                 sizeof(mb_param),&mb_param);
758
759                 s->s3->write_sequence[7] += mb_param.interleave;
760                 if (s->s3->write_sequence[7] < mb_param.interleave)
761                         {
762                         int j=6;
763                         while (j>=0 && (++s->s3->write_sequence[j--])==0) ;
764                         }
765
766                 wb->offset=0;
767                 wb->left = packlen;
768
769                 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
770                 s->s3->wpend_tot=len;
771                 s->s3->wpend_buf=buf;
772                 s->s3->wpend_type=type;
773                 s->s3->wpend_ret=len;
774
775                 /* we now just need to write the buffer */
776                 return ssl3_write_pending(s,type,buf,len);
777                 } while (0);
778 #endif
779
780         /* 'create_empty_fragment' is true only when this function calls itself */
781         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done)
782                 {
783                 /* countermeasure against known-IV weakness in CBC ciphersuites
784                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
785
786                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
787                         {
788                         /* recursive function call with 'create_empty_fragment' set;
789                          * this prepares and buffers the data for an empty fragment
790                          * (these 'prefix_len' bytes are sent out later
791                          * together with the actual payload) */
792                         prefix_len = do_ssl3_write(s, type, buf, 0, 1);
793                         if (prefix_len <= 0)
794                                 goto err;
795
796                         if (prefix_len >
797                 (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD))
798                                 {
799                                 /* insufficient space */
800                                 SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
801                                 goto err;
802                                 }
803                         }
804                 
805                 s->s3->empty_fragment_done = 1;
806                 }
807
808         if (create_empty_fragment)
809                 {
810 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
811                 /* extra fragment would be couple of cipher blocks,
812                  * which would be multiple of SSL3_ALIGN_PAYLOAD, so
813                  * if we want to align the real payload, then we can
814                  * just pretent we simply have two headers. */
815                 align = (long)wb->buf + 2*SSL3_RT_HEADER_LENGTH;
816                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
817 #endif
818                 p = wb->buf + align;
819                 wb->offset  = align;
820                 }
821         else if (prefix_len)
822                 {
823                 p = wb->buf + wb->offset + prefix_len;
824                 }
825         else
826                 {
827 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
828                 align = (long)wb->buf + SSL3_RT_HEADER_LENGTH;
829                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
830 #endif
831                 p = wb->buf + align;
832                 wb->offset  = align;
833                 }
834
835         /* write the header */
836
837         *(p++)=type&0xff;
838         wr->type=type;
839
840         *(p++)=(s->version>>8);
841         /* Some servers hang if iniatial client hello is larger than 256
842          * bytes and record version number > TLS 1.0
843          */
844         if (s->state == SSL3_ST_CW_CLNT_HELLO_B
845                                 && !s->renegotiate
846                                 && TLS1_get_version(s) > TLS1_VERSION)
847                 *(p++) = 0x1;
848         else
849                 *(p++)=s->version&0xff;
850
851         /* field where we are to write out packet length */
852         plen=p; 
853         p+=2;
854         /* Explicit IV length, block ciphers appropriate version flag */
855         if (s->enc_write_ctx && SSL_USE_EXPLICIT_IV(s))
856                 {
857                 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
858                 if (mode == EVP_CIPH_CBC_MODE)
859                         {
860                         eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
861                         if (eivlen <= 1)
862                                 eivlen = 0;
863                         }
864                 /* Need explicit part of IV for GCM mode */
865                 else if (mode == EVP_CIPH_GCM_MODE)
866                         eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
867                 else
868                         eivlen = 0;
869                 }
870         else 
871                 eivlen = 0;
872
873         /* lets setup the record stuff. */
874         wr->data=p + eivlen;
875         wr->length=(int)len;
876         wr->input=(unsigned char *)buf;
877
878         /* we now 'read' from wr->input, wr->length bytes into
879          * wr->data */
880
881         /* first we compress */
882         if (s->compress != NULL)
883                 {
884                 if (!ssl3_do_compress(s))
885                         {
886                         SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
887                         goto err;
888                         }
889                 }
890         else
891                 {
892                 memcpy(wr->data,wr->input,wr->length);
893                 wr->input=wr->data;
894                 }
895
896         /* we should still have the output to wr->data and the input
897          * from wr->input.  Length should be wr->length.
898          * wr->data still points in the wb->buf */
899
900         if (!SSL_USE_ETM(s) && mac_size != 0)
901                 {
902                 if (s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0)
903                         goto err;
904                 wr->length+=mac_size;
905                 }
906
907         wr->input=p;
908         wr->data=p;
909
910         if (eivlen)
911                 {
912         /*      if (RAND_pseudo_bytes(p, eivlen) <= 0)
913                         goto err; */
914                 wr->length += eivlen;
915                 }
916
917         /* ssl3_enc can only have an error on read */
918         s->method->ssl3_enc->enc(s,1);
919
920         if (SSL_USE_ETM(s) && mac_size != 0)
921                 {
922                 if (s->method->ssl3_enc->mac(s,p + wr->length,1) < 0)
923                         goto err;
924                 wr->length+=mac_size;
925                 }
926
927         /* record length after mac and block padding */
928         s2n(wr->length,plen);
929
930         if (s->msg_callback)
931                 s->msg_callback(1, 0, SSL3_RT_HEADER, plen - 5, 5, s, s->msg_callback_arg);
932
933         /* we should now have
934          * wr->data pointing to the encrypted data, which is
935          * wr->length long */
936         wr->type=type; /* not needed but helps for debugging */
937         wr->length+=SSL3_RT_HEADER_LENGTH;
938
939         if (create_empty_fragment)
940                 {
941                 /* we are in a recursive call;
942                  * just return the length, don't write out anything here
943                  */
944                 return wr->length;
945                 }
946
947         /* now let's set up wb */
948         wb->left = prefix_len + wr->length;
949
950         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
951         s->s3->wpend_tot=len;
952         s->s3->wpend_buf=buf;
953         s->s3->wpend_type=type;
954         s->s3->wpend_ret=len;
955
956         /* we now just need to write the buffer */
957         return ssl3_write_pending(s,type,buf,len);
958 err:
959         return -1;
960         }
961
962 /* if s->s3->wbuf.left != 0, we need to call this */
963 int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
964         unsigned int len)
965         {
966         int i;
967         SSL3_BUFFER *wb=&(s->s3->wbuf);
968
969 /* XXXX */
970         if ((s->s3->wpend_tot > (int)len)
971                 || ((s->s3->wpend_buf != buf) &&
972                         !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER))
973                 || (s->s3->wpend_type != type))
974                 {
975                 SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
976                 return(-1);
977                 }
978
979         for (;;)
980                 {
981                 clear_sys_error();
982                 if (s->wbio != NULL)
983                         {
984                         s->rwstate=SSL_WRITING;
985                         i=BIO_write(s->wbio,
986                                 (char *)&(wb->buf[wb->offset]),
987                                 (unsigned int)wb->left);
988                         }
989                 else
990                         {
991                         SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
992                         i= -1;
993                         }
994                 if (i == wb->left)
995                         {
996                         wb->left=0;
997                         wb->offset+=i;
998                         if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
999                                 !SSL_IS_DTLS(s))
1000                                 ssl3_release_write_buffer(s);
1001                         s->rwstate=SSL_NOTHING;
1002                         return(s->s3->wpend_ret);
1003                         }
1004                 else if (i <= 0) {
1005                         if (s->version == DTLS1_VERSION ||
1006                             s->version == DTLS1_BAD_VER) {
1007                                 /* For DTLS, just drop it. That's kind of the whole
1008                                    point in using a datagram service */
1009                                 wb->left = 0;
1010                         }
1011                         return(i);
1012                 }
1013                 wb->offset+=i;
1014                 wb->left-=i;
1015                 }
1016         }
1017
1018 /* Return up to 'len' payload bytes received in 'type' records.
1019  * 'type' is one of the following:
1020  *
1021  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
1022  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
1023  *   -  0 (during a shutdown, no data has to be returned)
1024  *
1025  * If we don't have stored data to work from, read a SSL/TLS record first
1026  * (possibly multiple records if we still don't have anything to return).
1027  *
1028  * This function must handle any surprises the peer may have for us, such as
1029  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
1030  * a surprise, but handled as if it were), or renegotiation requests.
1031  * Also if record payloads contain fragments too small to process, we store
1032  * them until there is enough for the respective protocol (the record protocol
1033  * may use arbitrary fragmentation and even interleaving):
1034  *     Change cipher spec protocol
1035  *             just 1 byte needed, no need for keeping anything stored
1036  *     Alert protocol
1037  *             2 bytes needed (AlertLevel, AlertDescription)
1038  *     Handshake protocol
1039  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
1040  *             to detect unexpected Client Hello and Hello Request messages
1041  *             here, anything else is handled by higher layers
1042  *     Application data protocol
1043  *             none of our business
1044  */
1045 int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
1046         {
1047         int al,i,j,ret;
1048         unsigned int n;
1049         SSL3_RECORD *rr;
1050         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
1051
1052         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
1053                 if (!ssl3_setup_read_buffer(s))
1054                         return(-1);
1055
1056         if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE) && type) ||
1057             (peek && (type != SSL3_RT_APPLICATION_DATA)))
1058                 {
1059                 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
1060                 return -1;
1061                 }
1062
1063         if ((type == SSL3_RT_HANDSHAKE) && (s->s3->handshake_fragment_len > 0))
1064                 /* (partially) satisfy request from storage */
1065                 {
1066                 unsigned char *src = s->s3->handshake_fragment;
1067                 unsigned char *dst = buf;
1068                 unsigned int k;
1069
1070                 /* peek == 0 */
1071                 n = 0;
1072                 while ((len > 0) && (s->s3->handshake_fragment_len > 0))
1073                         {
1074                         *dst++ = *src++;
1075                         len--; s->s3->handshake_fragment_len--;
1076                         n++;
1077                         }
1078                 /* move any remaining fragment bytes: */
1079                 for (k = 0; k < s->s3->handshake_fragment_len; k++)
1080                         s->s3->handshake_fragment[k] = *src++;
1081                 return n;
1082         }
1083
1084         /* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
1085
1086         if (!s->in_handshake && SSL_in_init(s))
1087                 {
1088                 /* type == SSL3_RT_APPLICATION_DATA */
1089                 i=s->handshake_func(s);
1090                 if (i < 0) return(i);
1091                 if (i == 0)
1092                         {
1093                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1094                         return(-1);
1095                         }
1096                 }
1097 start:
1098         s->rwstate=SSL_NOTHING;
1099
1100         /* s->s3->rrec.type         - is the type of record
1101          * s->s3->rrec.data,    - data
1102          * s->s3->rrec.off,     - offset into 'data' for next read
1103          * s->s3->rrec.length,  - number of bytes. */
1104         rr = &(s->s3->rrec);
1105
1106         /* get new packet if necessary */
1107         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
1108                 {
1109                 ret=ssl3_get_record(s);
1110                 if (ret <= 0) return(ret);
1111                 }
1112
1113         /* we now have a packet which can be read and processed */
1114
1115         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
1116                                        * reset by ssl3_get_finished */
1117                 && (rr->type != SSL3_RT_HANDSHAKE))
1118                 {
1119                 al=SSL_AD_UNEXPECTED_MESSAGE;
1120                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
1121                 goto f_err;
1122                 }
1123
1124         /* If the other end has shut down, throw anything we read away
1125          * (even in 'peek' mode) */
1126         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
1127                 {
1128                 rr->length=0;
1129                 s->rwstate=SSL_NOTHING;
1130                 return(0);
1131                 }
1132
1133
1134         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
1135                 {
1136                 /* make sure that we are not getting application data when we
1137                  * are doing a handshake for the first time */
1138                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
1139                         (s->enc_read_ctx == NULL))
1140                         {
1141                         al=SSL_AD_UNEXPECTED_MESSAGE;
1142                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
1143                         goto f_err;
1144                         }
1145
1146                 if (len <= 0) return(len);
1147
1148                 if ((unsigned int)len > rr->length)
1149                         n = rr->length;
1150                 else
1151                         n = (unsigned int)len;
1152
1153                 memcpy(buf,&(rr->data[rr->off]),n);
1154                 if (!peek)
1155                         {
1156                         rr->length-=n;
1157                         rr->off+=n;
1158                         if (rr->length == 0)
1159                                 {
1160                                 s->rstate=SSL_ST_READ_HEADER;
1161                                 rr->off=0;
1162                                 if (s->mode & SSL_MODE_RELEASE_BUFFERS)
1163                                         ssl3_release_read_buffer(s);
1164                                 }
1165                         }
1166                 return(n);
1167                 }
1168
1169
1170         /* If we get here, then type != rr->type; if we have a handshake
1171          * message, then it was unexpected (Hello Request or Client Hello). */
1172
1173         /* In case of record types for which we have 'fragment' storage,
1174          * fill that so that we can process the data at a fixed place.
1175          */
1176                 {
1177                 unsigned int dest_maxlen = 0;
1178                 unsigned char *dest = NULL;
1179                 unsigned int *dest_len = NULL;
1180
1181                 if (rr->type == SSL3_RT_HANDSHAKE)
1182                         {
1183                         dest_maxlen = sizeof s->s3->handshake_fragment;
1184                         dest = s->s3->handshake_fragment;
1185                         dest_len = &s->s3->handshake_fragment_len;
1186                         }
1187                 else if (rr->type == SSL3_RT_ALERT)
1188                         {
1189                         dest_maxlen = sizeof s->s3->alert_fragment;
1190                         dest = s->s3->alert_fragment;
1191                         dest_len = &s->s3->alert_fragment_len;
1192                         }
1193 #ifndef OPENSSL_NO_HEARTBEATS
1194                 else if (rr->type == TLS1_RT_HEARTBEAT)
1195                         {
1196                         tls1_process_heartbeat(s);
1197
1198                         /* Exit and notify application to read again */
1199                         rr->length = 0;
1200                         s->rwstate=SSL_READING;
1201                         BIO_clear_retry_flags(SSL_get_rbio(s));
1202                         BIO_set_retry_read(SSL_get_rbio(s));
1203                         return(-1);
1204                         }
1205 #endif
1206
1207                 if (dest_maxlen > 0)
1208                         {
1209                         n = dest_maxlen - *dest_len; /* available space in 'dest' */
1210                         if (rr->length < n)
1211                                 n = rr->length; /* available bytes */
1212
1213                         /* now move 'n' bytes: */
1214                         while (n-- > 0)
1215                                 {
1216                                 dest[(*dest_len)++] = rr->data[rr->off++];
1217                                 rr->length--;
1218                                 }
1219
1220                         if (*dest_len < dest_maxlen)
1221                                 goto start; /* fragment was too small */
1222                         }
1223                 }
1224
1225         /* s->s3->handshake_fragment_len == 4  iff  rr->type == SSL3_RT_HANDSHAKE;
1226          * s->s3->alert_fragment_len == 2      iff  rr->type == SSL3_RT_ALERT.
1227          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1228
1229         /* If we are a client, check for an incoming 'Hello Request': */
1230         if ((!s->server) &&
1231                 (s->s3->handshake_fragment_len >= 4) &&
1232                 (s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1233                 (s->session != NULL) && (s->session->cipher != NULL))
1234                 {
1235                 s->s3->handshake_fragment_len = 0;
1236
1237                 if ((s->s3->handshake_fragment[1] != 0) ||
1238                         (s->s3->handshake_fragment[2] != 0) ||
1239                         (s->s3->handshake_fragment[3] != 0))
1240                         {
1241                         al=SSL_AD_DECODE_ERROR;
1242                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1243                         goto f_err;
1244                         }
1245
1246                 if (s->msg_callback)
1247                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->s3->handshake_fragment, 4, s, s->msg_callback_arg);
1248
1249                 if (SSL_is_init_finished(s) &&
1250                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1251                         !s->s3->renegotiate)
1252                         {
1253                         ssl3_renegotiate(s);
1254                         if (ssl3_renegotiate_check(s))
1255                                 {
1256                                 i=s->handshake_func(s);
1257                                 if (i < 0) return(i);
1258                                 if (i == 0)
1259                                         {
1260                                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1261                                         return(-1);
1262                                         }
1263
1264                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1265                                         {
1266                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1267                                                 {
1268                                                 BIO *bio;
1269                                                 /* In the case where we try to read application data,
1270                                                  * but we trigger an SSL handshake, we return -1 with
1271                                                  * the retry option set.  Otherwise renegotiation may
1272                                                  * cause nasty problems in the blocking world */
1273                                                 s->rwstate=SSL_READING;
1274                                                 bio=SSL_get_rbio(s);
1275                                                 BIO_clear_retry_flags(bio);
1276                                                 BIO_set_retry_read(bio);
1277                                                 return(-1);
1278                                                 }
1279                                         }
1280                                 }
1281                         }
1282                 /* we either finished a handshake or ignored the request,
1283                  * now try again to obtain the (application) data we were asked for */
1284                 goto start;
1285                 }
1286         /* If we are a server and get a client hello when renegotiation isn't
1287          * allowed send back a no renegotiation alert and carry on.
1288          * WARNING: experimental code, needs reviewing (steve)
1289          */
1290         if (s->server &&
1291                 SSL_is_init_finished(s) &&
1292                 !s->s3->send_connection_binding &&
1293                 (s->version > SSL3_VERSION) &&
1294                 (s->s3->handshake_fragment_len >= 4) &&
1295                 (s->s3->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) &&
1296                 (s->session != NULL) && (s->session->cipher != NULL) &&
1297                 !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
1298                 
1299                 {
1300                 /*s->s3->handshake_fragment_len = 0;*/
1301                 rr->length = 0;
1302                 ssl3_send_alert(s,SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
1303                 goto start;
1304                 }
1305         if (s->s3->alert_fragment_len >= 2)
1306                 {
1307                 int alert_level = s->s3->alert_fragment[0];
1308                 int alert_descr = s->s3->alert_fragment[1];
1309
1310                 s->s3->alert_fragment_len = 0;
1311
1312                 if (s->msg_callback)
1313                         s->msg_callback(0, s->version, SSL3_RT_ALERT, s->s3->alert_fragment, 2, s, s->msg_callback_arg);
1314
1315                 if (s->info_callback != NULL)
1316                         cb=s->info_callback;
1317                 else if (s->ctx->info_callback != NULL)
1318                         cb=s->ctx->info_callback;
1319
1320                 if (cb != NULL)
1321                         {
1322                         j = (alert_level << 8) | alert_descr;
1323                         cb(s, SSL_CB_READ_ALERT, j);
1324                         }
1325
1326                 if (alert_level == 1) /* warning */
1327                         {
1328                         s->s3->warn_alert = alert_descr;
1329                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1330                                 {
1331                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1332                                 return(0);
1333                                 }
1334                         /* This is a warning but we receive it if we requested
1335                          * renegotiation and the peer denied it. Terminate with
1336                          * a fatal alert because if application tried to
1337                          * renegotiatie it presumably had a good reason and
1338                          * expects it to succeed.
1339                          *
1340                          * In future we might have a renegotiation where we
1341                          * don't care if the peer refused it where we carry on.
1342                          */
1343                         else if (alert_descr == SSL_AD_NO_RENEGOTIATION)
1344                                 {
1345                                 al = SSL_AD_HANDSHAKE_FAILURE;
1346                                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_NO_RENEGOTIATION);
1347                                 goto f_err;
1348                                 }
1349 #ifdef SSL_AD_MISSING_SRP_USERNAME
1350                         else if (alert_descr == SSL_AD_MISSING_SRP_USERNAME)
1351                                 return(0);
1352 #endif
1353                         }
1354                 else if (alert_level == 2) /* fatal */
1355                         {
1356                         char tmp[16];
1357
1358                         s->rwstate=SSL_NOTHING;
1359                         s->s3->fatal_alert = alert_descr;
1360                         SSLerr(SSL_F_SSL3_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1361                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1362                         ERR_add_error_data(2,"SSL alert number ",tmp);
1363                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1364                         SSL_CTX_remove_session(s->ctx,s->session);
1365                         return(0);
1366                         }
1367                 else
1368                         {
1369                         al=SSL_AD_ILLEGAL_PARAMETER;
1370                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1371                         goto f_err;
1372                         }
1373
1374                 goto start;
1375                 }
1376
1377         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1378                 {
1379                 s->rwstate=SSL_NOTHING;
1380                 rr->length=0;
1381                 return(0);
1382                 }
1383
1384         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1385                 {
1386                 /* 'Change Cipher Spec' is just a single byte, so we know
1387                  * exactly what the record payload has to look like */
1388                 if (    (rr->length != 1) || (rr->off != 0) ||
1389                         (rr->data[0] != SSL3_MT_CCS))
1390                         {
1391                         al=SSL_AD_ILLEGAL_PARAMETER;
1392                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1393                         goto f_err;
1394                         }
1395
1396                 /* Check we have a cipher to change to */
1397                 if (s->s3->tmp.new_cipher == NULL)
1398                         {
1399                         al=SSL_AD_UNEXPECTED_MESSAGE;
1400                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
1401                         goto f_err;
1402                         }
1403
1404                 rr->length=0;
1405
1406                 if (s->msg_callback)
1407                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, s->msg_callback_arg);
1408
1409                 s->s3->change_cipher_spec=1;
1410                 if (!ssl3_do_change_cipher_spec(s))
1411                         goto err;
1412                 else
1413                         goto start;
1414                 }
1415
1416         /* Unexpected handshake message (Client Hello, or protocol violation) */
1417         if ((s->s3->handshake_fragment_len >= 4) &&     !s->in_handshake)
1418                 {
1419                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1420                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1421                         {
1422 #if 0 /* worked only because C operator preferences are not as expected (and
1423        * because this is not really needed for clients except for detecting
1424        * protocol violations): */
1425                         s->state=SSL_ST_BEFORE|(s->server)
1426                                 ?SSL_ST_ACCEPT
1427                                 :SSL_ST_CONNECT;
1428 #else
1429                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1430 #endif
1431                         s->renegotiate=1;
1432                         s->new_session=1;
1433                         }
1434                 i=s->handshake_func(s);
1435                 if (i < 0) return(i);
1436                 if (i == 0)
1437                         {
1438                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1439                         return(-1);
1440                         }
1441
1442                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1443                         {
1444                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1445                                 {
1446                                 BIO *bio;
1447                                 /* In the case where we try to read application data,
1448                                  * but we trigger an SSL handshake, we return -1 with
1449                                  * the retry option set.  Otherwise renegotiation may
1450                                  * cause nasty problems in the blocking world */
1451                                 s->rwstate=SSL_READING;
1452                                 bio=SSL_get_rbio(s);
1453                                 BIO_clear_retry_flags(bio);
1454                                 BIO_set_retry_read(bio);
1455                                 return(-1);
1456                                 }
1457                         }
1458                 goto start;
1459                 }
1460
1461         switch (rr->type)
1462                 {
1463         default:
1464 #ifndef OPENSSL_NO_TLS
1465                 /* TLS up to v1.1 just ignores unknown message types:
1466                  * TLS v1.2 give an unexpected message alert.
1467                  */
1468                 if (s->version >= TLS1_VERSION && s->version <= TLS1_1_VERSION)
1469                         {
1470                         rr->length = 0;
1471                         goto start;
1472                         }
1473 #endif
1474                 al=SSL_AD_UNEXPECTED_MESSAGE;
1475                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1476                 goto f_err;
1477         case SSL3_RT_CHANGE_CIPHER_SPEC:
1478         case SSL3_RT_ALERT:
1479         case SSL3_RT_HANDSHAKE:
1480                 /* we already handled all of these, with the possible exception
1481                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1482                  * should not happen when type != rr->type */
1483                 al=SSL_AD_UNEXPECTED_MESSAGE;
1484                 SSLerr(SSL_F_SSL3_READ_BYTES,ERR_R_INTERNAL_ERROR);
1485                 goto f_err;
1486         case SSL3_RT_APPLICATION_DATA:
1487                 /* At this point, we were expecting handshake data,
1488                  * but have application data.  If the library was
1489                  * running inside ssl3_read() (i.e. in_read_app_data
1490                  * is set) and it makes sense to read application data
1491                  * at this point (session renegotiation not yet started),
1492                  * we will indulge it.
1493                  */
1494                 if (s->s3->in_read_app_data &&
1495                         (s->s3->total_renegotiations != 0) &&
1496                         ((
1497                                 (s->state & SSL_ST_CONNECT) &&
1498                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1499                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1500                                 ) || (
1501                                         (s->state & SSL_ST_ACCEPT) &&
1502                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1503                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1504                                         )
1505                                 ))
1506                         {
1507                         s->s3->in_read_app_data=2;
1508                         return(-1);
1509                         }
1510                 else
1511                         {
1512                         al=SSL_AD_UNEXPECTED_MESSAGE;
1513                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1514                         goto f_err;
1515                         }
1516                 }
1517         /* not reached */
1518
1519 f_err:
1520         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1521 err:
1522         return(-1);
1523         }
1524
1525 int ssl3_do_change_cipher_spec(SSL *s)
1526         {
1527         int i;
1528         const char *sender;
1529         int slen;
1530
1531         if (s->state & SSL_ST_ACCEPT)
1532                 i=SSL3_CHANGE_CIPHER_SERVER_READ;
1533         else
1534                 i=SSL3_CHANGE_CIPHER_CLIENT_READ;
1535
1536         if (s->s3->tmp.key_block == NULL)
1537                 {
1538                 if (s->session == NULL) 
1539                         {
1540                         /* might happen if dtls1_read_bytes() calls this */
1541                         SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_CCS_RECEIVED_EARLY);
1542                         return (0);
1543                         }
1544
1545                 s->session->cipher=s->s3->tmp.new_cipher;
1546                 if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
1547                 }
1548
1549         if (!s->method->ssl3_enc->change_cipher_state(s,i))
1550                 return(0);
1551
1552         /* we have to record the message digest at
1553          * this point so we can get it before we read
1554          * the finished message */
1555         if (s->state & SSL_ST_CONNECT)
1556                 {
1557                 sender=s->method->ssl3_enc->server_finished_label;
1558                 slen=s->method->ssl3_enc->server_finished_label_len;
1559                 }
1560         else
1561                 {
1562                 sender=s->method->ssl3_enc->client_finished_label;
1563                 slen=s->method->ssl3_enc->client_finished_label_len;
1564                 }
1565
1566         i = s->method->ssl3_enc->final_finish_mac(s,
1567                 sender,slen,s->s3->tmp.peer_finish_md);
1568         if (i == 0)
1569                 {
1570                 SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
1571                 return 0;
1572                 }
1573         s->s3->tmp.peer_finish_md_len = i;
1574
1575         return(1);
1576         }
1577
1578 int ssl3_send_alert(SSL *s, int level, int desc)
1579         {
1580         /* Map tls/ssl alert value to correct one */
1581         desc=s->method->ssl3_enc->alert_value(desc);
1582         if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION)
1583                 desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have protocol_version alerts */
1584         if (desc < 0) return -1;
1585         /* If a fatal one, remove from cache */
1586         if ((level == 2) && (s->session != NULL))
1587                 SSL_CTX_remove_session(s->ctx,s->session);
1588
1589         s->s3->alert_dispatch=1;
1590         s->s3->send_alert[0]=level;
1591         s->s3->send_alert[1]=desc;
1592         if (s->s3->wbuf.left == 0) /* data still being written out? */
1593                 return s->method->ssl_dispatch_alert(s);
1594         /* else data is still being written out, we will get written
1595          * some time in the future */
1596         return -1;
1597         }
1598
1599 int ssl3_dispatch_alert(SSL *s)
1600         {
1601         int i,j;
1602         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1603
1604         s->s3->alert_dispatch=0;
1605         i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0);
1606         if (i <= 0)
1607                 {
1608                 s->s3->alert_dispatch=1;
1609                 }
1610         else
1611                 {
1612                 /* Alert sent to BIO.  If it is important, flush it now.
1613                  * If the message does not get sent due to non-blocking IO,
1614                  * we will not worry too much. */
1615                 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1616                         (void)BIO_flush(s->wbio);
1617
1618                 if (s->msg_callback)
1619                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s, s->msg_callback_arg);
1620
1621                 if (s->info_callback != NULL)
1622                         cb=s->info_callback;
1623                 else if (s->ctx->info_callback != NULL)
1624                         cb=s->ctx->info_callback;
1625
1626                 if (cb != NULL)
1627                         {
1628                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1629                         cb(s,SSL_CB_WRITE_ALERT,j);
1630                         }
1631                 }
1632         return(i);
1633         }