e_aes_cbc_hmac_sha1.c: handle zero-length payload and engage empty frag
[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 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
121                          unsigned int len, int create_empty_fragment);
122 static int ssl3_get_record(SSL *s);
123
124 int ssl3_read_n(SSL *s, int n, int max, int extend)
125         {
126         /* If extend == 0, obtain new n-byte packet; if extend == 1, increase
127          * packet by another n bytes.
128          * The packet will be in the sub-array of s->s3->rbuf.buf specified
129          * by s->packet and s->packet_length.
130          * (If s->read_ahead is set, 'max' bytes may be stored in rbuf
131          * [plus s->packet_length bytes if extend == 1].)
132          */
133         int i,len,left;
134         long align=0;
135         unsigned char *pkt;
136         SSL3_BUFFER *rb;
137
138         if (n <= 0) return n;
139
140         rb    = &(s->s3->rbuf);
141         if (rb->buf == NULL)
142                 if (!ssl3_setup_read_buffer(s))
143                         return -1;
144
145         left  = rb->left;
146 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
147         align = (long)rb->buf + SSL3_RT_HEADER_LENGTH;
148         align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
149 #endif
150
151         if (!extend)
152                 {
153                 /* start with empty packet ... */
154                 if (left == 0)
155                         rb->offset = align;
156                 else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH)
157                         {
158                         /* check if next packet length is large
159                          * enough to justify payload alignment... */
160                         pkt = rb->buf + rb->offset;
161                         if (pkt[0] == SSL3_RT_APPLICATION_DATA
162                             && (pkt[3]<<8|pkt[4]) >= 128)
163                                 {
164                                 /* Note that even if packet is corrupted
165                                  * and its length field is insane, we can
166                                  * only be led to wrong decision about
167                                  * whether memmove will occur or not.
168                                  * Header values has no effect on memmove
169                                  * arguments and therefore no buffer
170                                  * overrun can be triggered. */
171                                 memmove (rb->buf+align,pkt,left);
172                                 rb->offset = align;
173                                 }
174                         }
175                 s->packet = rb->buf + rb->offset;
176                 s->packet_length = 0;
177                 /* ... now we can act as if 'extend' was set */
178                 }
179
180         /* For DTLS/UDP reads should not span multiple packets
181          * because the read operation returns the whole packet
182          * at once (as long as it fits into the buffer). */
183         if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
184                 {
185                 if (left > 0 && n > left)
186                         n = left;
187                 }
188
189         /* if there is enough in the buffer from a previous read, take some */
190         if (left >= n)
191                 {
192                 s->packet_length+=n;
193                 rb->left=left-n;
194                 rb->offset+=n;
195                 return(n);
196                 }
197
198         /* else we need to read more data */
199
200         len = s->packet_length;
201         pkt = rb->buf+align;
202         /* Move any available bytes to front of buffer:
203          * 'len' bytes already pointed to by 'packet',
204          * 'left' extra ones at the end */
205         if (s->packet != pkt) /* len > 0 */
206                 {
207                 memmove(pkt, s->packet, len+left);
208                 s->packet = pkt;
209                 rb->offset = len + align;
210                 }
211
212         if (n > (int)(rb->len - rb->offset)) /* does not happen */
213                 {
214                 SSLerr(SSL_F_SSL3_READ_N,ERR_R_INTERNAL_ERROR);
215                 return -1;
216                 }
217
218         if (!s->read_ahead)
219                 /* ignore max parameter */
220                 max = n;
221         else
222                 {
223                 if (max < n)
224                         max = n;
225                 if (max > (int)(rb->len - rb->offset))
226                         max = rb->len - rb->offset;
227                 }
228
229         while (left < n)
230                 {
231                 /* Now we have len+left bytes at the front of s->s3->rbuf.buf
232                  * and need to read in more until we have len+n (up to
233                  * len+max if possible) */
234
235                 clear_sys_error();
236                 if (s->rbio != NULL)
237                         {
238                         s->rwstate=SSL_READING;
239                         i=BIO_read(s->rbio,pkt+len+left, max-left);
240                         }
241                 else
242                         {
243                         SSLerr(SSL_F_SSL3_READ_N,SSL_R_READ_BIO_NOT_SET);
244                         i = -1;
245                         }
246
247                 if (i <= 0)
248                         {
249                         rb->left = left;
250                         if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
251                             SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
252                                 if (len+left == 0)
253                                         ssl3_release_read_buffer(s);
254                         return(i);
255                         }
256                 left+=i;
257                 /* reads should *never* span multiple packets for DTLS because
258                  * the underlying transport protocol is message oriented as opposed
259                  * to byte oriented as in the TLS case. */
260                 if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
261                         {
262                         if (n > left)
263                                 n = left; /* makes the while condition false */
264                         }
265                 }
266
267         /* done reading, now the book-keeping */
268         rb->offset += n;
269         rb->left = left - n;
270         s->packet_length += n;
271         s->rwstate=SSL_NOTHING;
272         return(n);
273         }
274
275 /* Call this to get a new input record.
276  * It will return <= 0 if more data is needed, normally due to an error
277  * or non-blocking IO.
278  * When it finishes, one packet has been decoded and can be found in
279  * ssl->s3->rrec.type    - is the type of record
280  * ssl->s3->rrec.data,   - data
281  * ssl->s3->rrec.length, - number of bytes
282  */
283 /* used only by ssl3_read_bytes */
284 static int ssl3_get_record(SSL *s)
285         {
286         int ssl_major,ssl_minor,al;
287         int enc_err,n,i,ret= -1;
288         SSL3_RECORD *rr;
289         SSL_SESSION *sess;
290         unsigned char *p;
291         unsigned char md[EVP_MAX_MD_SIZE];
292         short version;
293         int mac_size;
294         int clear=0;
295         size_t extra;
296         int decryption_failed_or_bad_record_mac = 0;
297         unsigned char *mac = NULL;
298
299         rr= &(s->s3->rrec);
300         sess=s->session;
301
302         if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
303                 extra=SSL3_RT_MAX_EXTRA;
304         else
305                 extra=0;
306         if (extra && !s->s3->init_extra)
307                 {
308                 /* An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
309                  * set after ssl3_setup_buffers() was done */
310                 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
311                 return -1;
312                 }
313
314 again:
315         /* check if we have the header */
316         if (    (s->rstate != SSL_ST_READ_BODY) ||
317                 (s->packet_length < SSL3_RT_HEADER_LENGTH)) 
318                 {
319                 n=ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
320                 if (n <= 0) return(n); /* error or non-blocking */
321                 s->rstate=SSL_ST_READ_BODY;
322
323                 p=s->packet;
324
325                 /* Pull apart the header into the SSL3_RECORD */
326                 rr->type= *(p++);
327                 ssl_major= *(p++);
328                 ssl_minor= *(p++);
329                 version=(ssl_major<<8)|ssl_minor;
330                 n2s(p,rr->length);
331 #if 0
332 fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length);
333 #endif
334
335                 /* Lets check version */
336                 if (!s->first_packet)
337                         {
338                         if (version != s->version)
339                                 {
340                                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
341                                 if ((s->version & 0xFF00) == (version & 0xFF00))
342                                         /* Send back error using their minor version number :-) */
343                                         s->version = (unsigned short)version;
344                                 al=SSL_AD_PROTOCOL_VERSION;
345                                 goto f_err;
346                                 }
347                         }
348
349                 if ((version>>8) != SSL3_VERSION_MAJOR)
350                         {
351                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
352                         goto err;
353                         }
354
355                 if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH)
356                         {
357                         al=SSL_AD_RECORD_OVERFLOW;
358                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
359                         goto f_err;
360                         }
361
362                 /* now s->rstate == SSL_ST_READ_BODY */
363                 }
364
365         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
366
367         if (rr->length > s->packet_length-SSL3_RT_HEADER_LENGTH)
368                 {
369                 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
370                 i=rr->length;
371                 n=ssl3_read_n(s,i,i,1);
372                 if (n <= 0) return(n); /* error or non-blocking io */
373                 /* now n == rr->length,
374                  * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */
375                 }
376
377         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
378
379         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
380          * and we have that many bytes in s->packet
381          */
382         rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);
383
384         /* ok, we can now read from 's->packet' data into 'rr'
385          * rr->input points at rr->length bytes, which
386          * need to be copied into rr->data by either
387          * the decryption or by the decompression
388          * When the data is 'copied' into the rr->data buffer,
389          * rr->input will be pointed at the new buffer */ 
390
391         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
392          * rr->length bytes of encrypted compressed stuff. */
393
394         /* check is not needed I believe */
395         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
396                 {
397                 al=SSL_AD_RECORD_OVERFLOW;
398                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
399                 goto f_err;
400                 }
401
402         /* decrypt in place in 'rr->input' */
403         rr->data=rr->input;
404
405         enc_err = s->method->ssl3_enc->enc(s,0);
406         if (enc_err <= 0)
407                 {
408                 if (enc_err == 0)
409                         /* SSLerr() and ssl3_send_alert() have been called */
410                         goto err;
411
412                 /* Otherwise enc_err == -1, which indicates bad padding
413                  * (rec->length has not been changed in this case).
414                  * To minimize information leaked via timing, we will perform
415                  * the MAC computation anyway. */
416                 decryption_failed_or_bad_record_mac = 1;
417                 }
418
419 #ifdef TLS_DEBUG
420 printf("dec %d\n",rr->length);
421 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
422 printf("\n");
423 #endif
424
425         /* r->length is now the compressed data plus mac */
426         if (    (sess == NULL) ||
427                 (s->enc_read_ctx == NULL) ||
428                 (EVP_MD_CTX_md(s->read_hash) == NULL))
429                 clear=1;
430
431         if (!clear)
432                 {
433                 /* !clear => s->read_hash != NULL => mac_size != -1 */
434                 mac_size=EVP_MD_CTX_size(s->read_hash);
435                 OPENSSL_assert(mac_size >= 0);
436
437                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
438                         {
439 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
440                         al=SSL_AD_RECORD_OVERFLOW;
441                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
442                         goto f_err;
443 #else
444                         decryption_failed_or_bad_record_mac = 1;
445 #endif                  
446                         }
447                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
448                 if (rr->length >= (unsigned int)mac_size)
449                         {
450                         rr->length -= mac_size;
451                         mac = &rr->data[rr->length];
452                         }
453                 else
454                         {
455                         /* record (minus padding) is too short to contain a MAC */
456 #if 0 /* OK only for stream ciphers */
457                         al=SSL_AD_DECODE_ERROR;
458                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
459                         goto f_err;
460 #else
461                         decryption_failed_or_bad_record_mac = 1;
462                         rr->length = 0;
463 #endif
464                         }
465                 i=s->method->ssl3_enc->mac(s,md,0);
466                 if (i < 0 || mac == NULL || memcmp(md, mac, (size_t)mac_size) != 0)
467                         {
468                         decryption_failed_or_bad_record_mac = 1;
469                         }
470                 }
471
472         if (decryption_failed_or_bad_record_mac)
473                 {
474                 /* A separate 'decryption_failed' alert was introduced with TLS 1.0,
475                  * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
476                  * failure is directly visible from the ciphertext anyway,
477                  * we should not reveal which kind of error occured -- this
478                  * might become visible to an attacker (e.g. via a logfile) */
479                 al=SSL_AD_BAD_RECORD_MAC;
480                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
481                 goto f_err;
482                 }
483
484         /* r->length is now just compressed */
485         if (s->expand != NULL)
486                 {
487                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
488                         {
489                         al=SSL_AD_RECORD_OVERFLOW;
490                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
491                         goto f_err;
492                         }
493                 if (!ssl3_do_uncompress(s))
494                         {
495                         al=SSL_AD_DECOMPRESSION_FAILURE;
496                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
497                         goto f_err;
498                         }
499                 }
500
501         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH+extra)
502                 {
503                 al=SSL_AD_RECORD_OVERFLOW;
504                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
505                 goto f_err;
506                 }
507
508         rr->off=0;
509         /* So at this point the following is true
510          * ssl->s3->rrec.type   is the type of record
511          * ssl->s3->rrec.length == number of bytes in record
512          * ssl->s3->rrec.off    == offset to first valid byte
513          * ssl->s3->rrec.data   == where to take bytes from, increment
514          *                         after use :-).
515          */
516
517         /* we have pulled in a full packet so zero things */
518         s->packet_length=0;
519
520         /* just read a 0 length packet */
521         if (rr->length == 0) goto again;
522
523 #if 0
524 fprintf(stderr, "Ultimate Record type=%d, Length=%d\n", rr->type, rr->length);
525 #endif
526
527         return(1);
528
529 f_err:
530         ssl3_send_alert(s,SSL3_AL_FATAL,al);
531 err:
532         return(ret);
533         }
534
535 int ssl3_do_uncompress(SSL *ssl)
536         {
537 #ifndef OPENSSL_NO_COMP
538         int i;
539         SSL3_RECORD *rr;
540
541         rr= &(ssl->s3->rrec);
542         i=COMP_expand_block(ssl->expand,rr->comp,
543                 SSL3_RT_MAX_PLAIN_LENGTH,rr->data,(int)rr->length);
544         if (i < 0)
545                 return(0);
546         else
547                 rr->length=i;
548         rr->data=rr->comp;
549 #endif
550         return(1);
551         }
552
553 int ssl3_do_compress(SSL *ssl)
554         {
555 #ifndef OPENSSL_NO_COMP
556         int i;
557         SSL3_RECORD *wr;
558
559         wr= &(ssl->s3->wrec);
560         i=COMP_compress_block(ssl->compress,wr->data,
561                 SSL3_RT_MAX_COMPRESSED_LENGTH,
562                 wr->input,(int)wr->length);
563         if (i < 0)
564                 return(0);
565         else
566                 wr->length=i;
567
568         wr->input=wr->data;
569 #endif
570         return(1);
571         }
572
573 /* Call this to write data in records of type 'type'
574  * It will return <= 0 if not all data has been sent or non-blocking IO.
575  */
576 int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
577         {
578         const unsigned char *buf=buf_;
579         unsigned int tot,n,nw;
580         int i;
581
582         s->rwstate=SSL_NOTHING;
583         tot=s->s3->wnum;
584         s->s3->wnum=0;
585
586         if (SSL_in_init(s) && !s->in_handshake)
587                 {
588                 i=s->handshake_func(s);
589                 if (i < 0) return(i);
590                 if (i == 0)
591                         {
592                         SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
593                         return -1;
594                         }
595                 }
596
597         n=(len-tot);
598         for (;;)
599                 {
600                 if (n > s->max_send_fragment)
601                         nw=s->max_send_fragment;
602                 else
603                         nw=n;
604
605                 i=do_ssl3_write(s, type, &(buf[tot]), nw, 0);
606                 if (i <= 0)
607                         {
608                         s->s3->wnum=tot;
609                         return i;
610                         }
611
612                 if ((i == (int)n) ||
613                         (type == SSL3_RT_APPLICATION_DATA &&
614                          (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
615                         {
616                         /* next chunk of data should get another prepended empty fragment
617                          * in ciphersuites with known-IV weakness: */
618                         s->s3->empty_fragment_done = 0;
619                         
620                         return tot+i;
621                         }
622
623                 n-=i;
624                 tot+=i;
625                 }
626         }
627
628 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
629                          unsigned int len, int create_empty_fragment)
630         {
631         unsigned char *p,*plen;
632         int i,mac_size,clear=0;
633         int prefix_len=0;
634         int eivlen;
635         long align=0;
636         SSL3_RECORD *wr;
637         SSL3_BUFFER *wb=&(s->s3->wbuf);
638         SSL_SESSION *sess;
639
640         if (wb->buf == NULL)
641                 if (!ssl3_setup_write_buffer(s))
642                         return -1;
643
644         /* first check if there is a SSL3_BUFFER still being written
645          * out.  This will happen with non blocking IO */
646         if (wb->left != 0)
647                 return(ssl3_write_pending(s,type,buf,len));
648
649         /* If we have an alert to send, lets send it */
650         if (s->s3->alert_dispatch)
651                 {
652                 i=s->method->ssl_dispatch_alert(s);
653                 if (i <= 0)
654                         return(i);
655                 /* if it went, fall through and send more stuff */
656                 }
657
658         if (len == 0 && !create_empty_fragment)
659                 return 0;
660
661         wr= &(s->s3->wrec);
662         sess=s->session;
663
664         if (    (sess == NULL) ||
665                 (s->enc_write_ctx == NULL) ||
666                 (EVP_MD_CTX_md(s->write_hash) == NULL))
667                 {
668 #if 1
669                 clear=s->enc_write_ctx?0:1;     /* must be AEAD cipher */
670 #else
671                 clear=1;
672 #endif
673                 mac_size=0;
674                 }
675         else
676                 {
677                 mac_size=EVP_MD_CTX_size(s->write_hash);
678                 if (mac_size < 0)
679                         goto err;
680                 }
681
682         /* 'create_empty_fragment' is true only when this function calls itself */
683         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done)
684                 {
685                 /* countermeasure against known-IV weakness in CBC ciphersuites
686                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
687
688                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
689                         {
690                         /* recursive function call with 'create_empty_fragment' set;
691                          * this prepares and buffers the data for an empty fragment
692                          * (these 'prefix_len' bytes are sent out later
693                          * together with the actual payload) */
694                         prefix_len = do_ssl3_write(s, type, buf, 0, 1);
695                         if (prefix_len <= 0)
696                                 goto err;
697
698                         if (prefix_len >
699                 (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD))
700                                 {
701                                 /* insufficient space */
702                                 SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
703                                 goto err;
704                                 }
705                         }
706                 
707                 s->s3->empty_fragment_done = 1;
708                 }
709
710         if (create_empty_fragment)
711                 {
712 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
713                 /* extra fragment would be couple of cipher blocks,
714                  * which would be multiple of SSL3_ALIGN_PAYLOAD, so
715                  * if we want to align the real payload, then we can
716                  * just pretent we simply have two headers. */
717                 align = (long)wb->buf + 2*SSL3_RT_HEADER_LENGTH;
718                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
719 #endif
720                 p = wb->buf + align;
721                 wb->offset  = align;
722                 }
723         else if (prefix_len)
724                 {
725                 p = wb->buf + wb->offset + prefix_len;
726                 }
727         else
728                 {
729 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
730                 align = (long)wb->buf + SSL3_RT_HEADER_LENGTH;
731                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
732 #endif
733                 p = wb->buf + align;
734                 wb->offset  = align;
735                 }
736
737         /* write the header */
738
739         *(p++)=type&0xff;
740         wr->type=type;
741
742         *(p++)=(s->version>>8);
743         *(p++)=s->version&0xff;
744
745         /* field where we are to write out packet length */
746         plen=p; 
747         p+=2;
748         /* Explicit IV length, block ciphers and TLS version 1.1 or later */
749         if (s->enc_write_ctx && s->version >= TLS1_1_VERSION)
750                 {
751                 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
752                 if (mode == EVP_CIPH_CBC_MODE)
753                         {
754                         eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
755                         if (eivlen <= 1)
756                                 eivlen = 0;
757                         }
758                 /* Need explicit part of IV for GCM mode */
759                 else if (mode == EVP_CIPH_GCM_MODE)
760                         eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
761                 else
762                         eivlen = 0;
763                 }
764         else 
765                 eivlen = 0;
766
767         /* lets setup the record stuff. */
768         wr->data=p + eivlen;
769         wr->length=(int)len;
770         wr->input=(unsigned char *)buf;
771
772         /* we now 'read' from wr->input, wr->length bytes into
773          * wr->data */
774
775         /* first we compress */
776         if (s->compress != NULL)
777                 {
778                 if (!ssl3_do_compress(s))
779                         {
780                         SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
781                         goto err;
782                         }
783                 }
784         else
785                 {
786                 memcpy(wr->data,wr->input,wr->length);
787                 wr->input=wr->data;
788                 }
789
790         /* we should still have the output to wr->data and the input
791          * from wr->input.  Length should be wr->length.
792          * wr->data still points in the wb->buf */
793
794         if (mac_size != 0)
795                 {
796                 if (s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0)
797                         goto err;
798                 wr->length+=mac_size;
799                 }
800
801         wr->input=p;
802         wr->data=p;
803
804         if (eivlen)
805                 {
806         /*      if (RAND_pseudo_bytes(p, eivlen) <= 0)
807                         goto err; */
808                 wr->length += eivlen;
809                 }
810
811         /* ssl3_enc can only have an error on read */
812         s->method->ssl3_enc->enc(s,1);
813
814         /* record length after mac and block padding */
815         s2n(wr->length,plen);
816
817         /* we should now have
818          * wr->data pointing to the encrypted data, which is
819          * wr->length long */
820         wr->type=type; /* not needed but helps for debugging */
821         wr->length+=SSL3_RT_HEADER_LENGTH;
822
823         if (create_empty_fragment)
824                 {
825                 /* we are in a recursive call;
826                  * just return the length, don't write out anything here
827                  */
828                 return wr->length;
829                 }
830
831         /* now let's set up wb */
832         wb->left = prefix_len + wr->length;
833
834         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
835         s->s3->wpend_tot=len;
836         s->s3->wpend_buf=buf;
837         s->s3->wpend_type=type;
838         s->s3->wpend_ret=len;
839
840         /* we now just need to write the buffer */
841         return ssl3_write_pending(s,type,buf,len);
842 err:
843         return -1;
844         }
845
846 /* if s->s3->wbuf.left != 0, we need to call this */
847 int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
848         unsigned int len)
849         {
850         int i;
851         SSL3_BUFFER *wb=&(s->s3->wbuf);
852
853 /* XXXX */
854         if ((s->s3->wpend_tot > (int)len)
855                 || ((s->s3->wpend_buf != buf) &&
856                         !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER))
857                 || (s->s3->wpend_type != type))
858                 {
859                 SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
860                 return(-1);
861                 }
862
863         for (;;)
864                 {
865                 clear_sys_error();
866                 if (s->wbio != NULL)
867                         {
868                         s->rwstate=SSL_WRITING;
869                         i=BIO_write(s->wbio,
870                                 (char *)&(wb->buf[wb->offset]),
871                                 (unsigned int)wb->left);
872                         }
873                 else
874                         {
875                         SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
876                         i= -1;
877                         }
878                 if (i == wb->left)
879                         {
880                         wb->left=0;
881                         wb->offset+=i;
882                         if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
883                             SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
884                                 ssl3_release_write_buffer(s);
885                         s->rwstate=SSL_NOTHING;
886                         return(s->s3->wpend_ret);
887                         }
888                 else if (i <= 0) {
889                         if (s->version == DTLS1_VERSION ||
890                             s->version == DTLS1_BAD_VER) {
891                                 /* For DTLS, just drop it. That's kind of the whole
892                                    point in using a datagram service */
893                                 wb->left = 0;
894                         }
895                         return(i);
896                 }
897                 wb->offset+=i;
898                 wb->left-=i;
899                 }
900         }
901
902 /* Return up to 'len' payload bytes received in 'type' records.
903  * 'type' is one of the following:
904  *
905  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
906  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
907  *   -  0 (during a shutdown, no data has to be returned)
908  *
909  * If we don't have stored data to work from, read a SSL/TLS record first
910  * (possibly multiple records if we still don't have anything to return).
911  *
912  * This function must handle any surprises the peer may have for us, such as
913  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
914  * a surprise, but handled as if it were), or renegotiation requests.
915  * Also if record payloads contain fragments too small to process, we store
916  * them until there is enough for the respective protocol (the record protocol
917  * may use arbitrary fragmentation and even interleaving):
918  *     Change cipher spec protocol
919  *             just 1 byte needed, no need for keeping anything stored
920  *     Alert protocol
921  *             2 bytes needed (AlertLevel, AlertDescription)
922  *     Handshake protocol
923  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
924  *             to detect unexpected Client Hello and Hello Request messages
925  *             here, anything else is handled by higher layers
926  *     Application data protocol
927  *             none of our business
928  */
929 int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
930         {
931         int al,i,j,ret;
932         unsigned int n;
933         SSL3_RECORD *rr;
934         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
935
936         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
937                 if (!ssl3_setup_read_buffer(s))
938                         return(-1);
939
940         if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE) && type) ||
941             (peek && (type != SSL3_RT_APPLICATION_DATA)))
942                 {
943                 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
944                 return -1;
945                 }
946
947         if ((type == SSL3_RT_HANDSHAKE) && (s->s3->handshake_fragment_len > 0))
948                 /* (partially) satisfy request from storage */
949                 {
950                 unsigned char *src = s->s3->handshake_fragment;
951                 unsigned char *dst = buf;
952                 unsigned int k;
953
954                 /* peek == 0 */
955                 n = 0;
956                 while ((len > 0) && (s->s3->handshake_fragment_len > 0))
957                         {
958                         *dst++ = *src++;
959                         len--; s->s3->handshake_fragment_len--;
960                         n++;
961                         }
962                 /* move any remaining fragment bytes: */
963                 for (k = 0; k < s->s3->handshake_fragment_len; k++)
964                         s->s3->handshake_fragment[k] = *src++;
965                 return n;
966         }
967
968         /* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
969
970         if (!s->in_handshake && SSL_in_init(s))
971                 {
972                 /* type == SSL3_RT_APPLICATION_DATA */
973                 i=s->handshake_func(s);
974                 if (i < 0) return(i);
975                 if (i == 0)
976                         {
977                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
978                         return(-1);
979                         }
980                 }
981 start:
982         s->rwstate=SSL_NOTHING;
983
984         /* s->s3->rrec.type         - is the type of record
985          * s->s3->rrec.data,    - data
986          * s->s3->rrec.off,     - offset into 'data' for next read
987          * s->s3->rrec.length,  - number of bytes. */
988         rr = &(s->s3->rrec);
989
990         /* get new packet if necessary */
991         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
992                 {
993                 ret=ssl3_get_record(s);
994                 if (ret <= 0) return(ret);
995                 }
996
997         /* we now have a packet which can be read and processed */
998
999         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
1000                                        * reset by ssl3_get_finished */
1001                 && (rr->type != SSL3_RT_HANDSHAKE))
1002                 {
1003                 al=SSL_AD_UNEXPECTED_MESSAGE;
1004                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
1005                 goto f_err;
1006                 }
1007
1008         /* If the other end has shut down, throw anything we read away
1009          * (even in 'peek' mode) */
1010         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
1011                 {
1012                 rr->length=0;
1013                 s->rwstate=SSL_NOTHING;
1014                 return(0);
1015                 }
1016
1017
1018         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
1019                 {
1020                 /* make sure that we are not getting application data when we
1021                  * are doing a handshake for the first time */
1022                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
1023                         (s->enc_read_ctx == NULL))
1024                         {
1025                         al=SSL_AD_UNEXPECTED_MESSAGE;
1026                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
1027                         goto f_err;
1028                         }
1029
1030                 if (len <= 0) return(len);
1031
1032                 if ((unsigned int)len > rr->length)
1033                         n = rr->length;
1034                 else
1035                         n = (unsigned int)len;
1036
1037                 memcpy(buf,&(rr->data[rr->off]),n);
1038                 if (!peek)
1039                         {
1040                         rr->length-=n;
1041                         rr->off+=n;
1042                         if (rr->length == 0)
1043                                 {
1044                                 s->rstate=SSL_ST_READ_HEADER;
1045                                 rr->off=0;
1046                                 if (s->mode & SSL_MODE_RELEASE_BUFFERS)
1047                                         ssl3_release_read_buffer(s);
1048                                 }
1049                         }
1050                 return(n);
1051                 }
1052
1053
1054         /* If we get here, then type != rr->type; if we have a handshake
1055          * message, then it was unexpected (Hello Request or Client Hello). */
1056
1057         /* In case of record types for which we have 'fragment' storage,
1058          * fill that so that we can process the data at a fixed place.
1059          */
1060                 {
1061                 unsigned int dest_maxlen = 0;
1062                 unsigned char *dest = NULL;
1063                 unsigned int *dest_len = NULL;
1064
1065                 if (rr->type == SSL3_RT_HANDSHAKE)
1066                         {
1067                         dest_maxlen = sizeof s->s3->handshake_fragment;
1068                         dest = s->s3->handshake_fragment;
1069                         dest_len = &s->s3->handshake_fragment_len;
1070                         }
1071                 else if (rr->type == SSL3_RT_ALERT)
1072                         {
1073                         dest_maxlen = sizeof s->s3->alert_fragment;
1074                         dest = s->s3->alert_fragment;
1075                         dest_len = &s->s3->alert_fragment_len;
1076                         }
1077 #ifndef OPENSSL_NO_HEARTBEATS
1078                 else if (rr->type == TLS1_RT_HEARTBEAT)
1079                         {
1080                         tls1_process_heartbeat(s);
1081
1082                         /* Exit and notify application to read again */
1083                         rr->length = 0;
1084                         s->rwstate=SSL_READING;
1085                         BIO_clear_retry_flags(SSL_get_rbio(s));
1086                         BIO_set_retry_read(SSL_get_rbio(s));
1087                         return(-1);
1088                         }
1089 #endif
1090
1091                 if (dest_maxlen > 0)
1092                         {
1093                         n = dest_maxlen - *dest_len; /* available space in 'dest' */
1094                         if (rr->length < n)
1095                                 n = rr->length; /* available bytes */
1096
1097                         /* now move 'n' bytes: */
1098                         while (n-- > 0)
1099                                 {
1100                                 dest[(*dest_len)++] = rr->data[rr->off++];
1101                                 rr->length--;
1102                                 }
1103
1104                         if (*dest_len < dest_maxlen)
1105                                 goto start; /* fragment was too small */
1106                         }
1107                 }
1108
1109         /* s->s3->handshake_fragment_len == 4  iff  rr->type == SSL3_RT_HANDSHAKE;
1110          * s->s3->alert_fragment_len == 2      iff  rr->type == SSL3_RT_ALERT.
1111          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1112
1113         /* If we are a client, check for an incoming 'Hello Request': */
1114         if ((!s->server) &&
1115                 (s->s3->handshake_fragment_len >= 4) &&
1116                 (s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1117                 (s->session != NULL) && (s->session->cipher != NULL))
1118                 {
1119                 s->s3->handshake_fragment_len = 0;
1120
1121                 if ((s->s3->handshake_fragment[1] != 0) ||
1122                         (s->s3->handshake_fragment[2] != 0) ||
1123                         (s->s3->handshake_fragment[3] != 0))
1124                         {
1125                         al=SSL_AD_DECODE_ERROR;
1126                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1127                         goto f_err;
1128                         }
1129
1130                 if (s->msg_callback)
1131                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->s3->handshake_fragment, 4, s, s->msg_callback_arg);
1132
1133                 if (SSL_is_init_finished(s) &&
1134                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1135                         !s->s3->renegotiate)
1136                         {
1137                         ssl3_renegotiate(s);
1138                         if (ssl3_renegotiate_check(s))
1139                                 {
1140                                 i=s->handshake_func(s);
1141                                 if (i < 0) return(i);
1142                                 if (i == 0)
1143                                         {
1144                                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1145                                         return(-1);
1146                                         }
1147
1148                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1149                                         {
1150                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1151                                                 {
1152                                                 BIO *bio;
1153                                                 /* In the case where we try to read application data,
1154                                                  * but we trigger an SSL handshake, we return -1 with
1155                                                  * the retry option set.  Otherwise renegotiation may
1156                                                  * cause nasty problems in the blocking world */
1157                                                 s->rwstate=SSL_READING;
1158                                                 bio=SSL_get_rbio(s);
1159                                                 BIO_clear_retry_flags(bio);
1160                                                 BIO_set_retry_read(bio);
1161                                                 return(-1);
1162                                                 }
1163                                         }
1164                                 }
1165                         }
1166                 /* we either finished a handshake or ignored the request,
1167                  * now try again to obtain the (application) data we were asked for */
1168                 goto start;
1169                 }
1170         /* If we are a server and get a client hello when renegotiation isn't
1171          * allowed send back a no renegotiation alert and carry on.
1172          * WARNING: experimental code, needs reviewing (steve)
1173          */
1174         if (s->server &&
1175                 SSL_is_init_finished(s) &&
1176                 !s->s3->send_connection_binding &&
1177                 (s->version > SSL3_VERSION) &&
1178                 (s->s3->handshake_fragment_len >= 4) &&
1179                 (s->s3->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) &&
1180                 (s->session != NULL) && (s->session->cipher != NULL) &&
1181                 !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
1182                 
1183                 {
1184                 /*s->s3->handshake_fragment_len = 0;*/
1185                 rr->length = 0;
1186                 ssl3_send_alert(s,SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
1187                 goto start;
1188                 }
1189         if (s->s3->alert_fragment_len >= 2)
1190                 {
1191                 int alert_level = s->s3->alert_fragment[0];
1192                 int alert_descr = s->s3->alert_fragment[1];
1193
1194                 s->s3->alert_fragment_len = 0;
1195
1196                 if (s->msg_callback)
1197                         s->msg_callback(0, s->version, SSL3_RT_ALERT, s->s3->alert_fragment, 2, s, s->msg_callback_arg);
1198
1199                 if (s->info_callback != NULL)
1200                         cb=s->info_callback;
1201                 else if (s->ctx->info_callback != NULL)
1202                         cb=s->ctx->info_callback;
1203
1204                 if (cb != NULL)
1205                         {
1206                         j = (alert_level << 8) | alert_descr;
1207                         cb(s, SSL_CB_READ_ALERT, j);
1208                         }
1209
1210                 if (alert_level == 1) /* warning */
1211                         {
1212                         s->s3->warn_alert = alert_descr;
1213                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1214                                 {
1215                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1216                                 return(0);
1217                                 }
1218                         /* This is a warning but we receive it if we requested
1219                          * renegotiation and the peer denied it. Terminate with
1220                          * a fatal alert because if application tried to
1221                          * renegotiatie it presumably had a good reason and
1222                          * expects it to succeed.
1223                          *
1224                          * In future we might have a renegotiation where we
1225                          * don't care if the peer refused it where we carry on.
1226                          */
1227                         else if (alert_descr == SSL_AD_NO_RENEGOTIATION)
1228                                 {
1229                                 al = SSL_AD_HANDSHAKE_FAILURE;
1230                                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_NO_RENEGOTIATION);
1231                                 goto f_err;
1232                                 }
1233 #ifdef SSL_AD_MISSING_SRP_USERNAME
1234                         if (alert_descr == SSL_AD_MISSING_SRP_USERNAME)
1235                                 return(0);
1236 #endif
1237                         }
1238                 else if (alert_level == 2) /* fatal */
1239                         {
1240                         char tmp[16];
1241
1242                         s->rwstate=SSL_NOTHING;
1243                         s->s3->fatal_alert = alert_descr;
1244                         SSLerr(SSL_F_SSL3_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1245                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1246                         ERR_add_error_data(2,"SSL alert number ",tmp);
1247                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1248                         SSL_CTX_remove_session(s->ctx,s->session);
1249                         return(0);
1250                         }
1251                 else
1252                         {
1253                         al=SSL_AD_ILLEGAL_PARAMETER;
1254                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1255                         goto f_err;
1256                         }
1257
1258                 goto start;
1259                 }
1260
1261         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1262                 {
1263                 s->rwstate=SSL_NOTHING;
1264                 rr->length=0;
1265                 return(0);
1266                 }
1267
1268         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1269                 {
1270                 /* 'Change Cipher Spec' is just a single byte, so we know
1271                  * exactly what the record payload has to look like */
1272                 if (    (rr->length != 1) || (rr->off != 0) ||
1273                         (rr->data[0] != SSL3_MT_CCS))
1274                         {
1275                         al=SSL_AD_ILLEGAL_PARAMETER;
1276                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1277                         goto f_err;
1278                         }
1279
1280                 /* Check we have a cipher to change to */
1281                 if (s->s3->tmp.new_cipher == NULL)
1282                         {
1283                         al=SSL_AD_UNEXPECTED_MESSAGE;
1284                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
1285                         goto f_err;
1286                         }
1287
1288                 rr->length=0;
1289
1290                 if (s->msg_callback)
1291                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, s->msg_callback_arg);
1292
1293                 s->s3->change_cipher_spec=1;
1294                 if (!ssl3_do_change_cipher_spec(s))
1295                         goto err;
1296                 else
1297                         goto start;
1298                 }
1299
1300         /* Unexpected handshake message (Client Hello, or protocol violation) */
1301         if ((s->s3->handshake_fragment_len >= 4) &&     !s->in_handshake)
1302                 {
1303                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1304                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1305                         {
1306 #if 0 /* worked only because C operator preferences are not as expected (and
1307        * because this is not really needed for clients except for detecting
1308        * protocol violations): */
1309                         s->state=SSL_ST_BEFORE|(s->server)
1310                                 ?SSL_ST_ACCEPT
1311                                 :SSL_ST_CONNECT;
1312 #else
1313                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1314 #endif
1315                         s->renegotiate=1;
1316                         s->new_session=1;
1317                         }
1318                 i=s->handshake_func(s);
1319                 if (i < 0) return(i);
1320                 if (i == 0)
1321                         {
1322                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1323                         return(-1);
1324                         }
1325
1326                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1327                         {
1328                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1329                                 {
1330                                 BIO *bio;
1331                                 /* In the case where we try to read application data,
1332                                  * but we trigger an SSL handshake, we return -1 with
1333                                  * the retry option set.  Otherwise renegotiation may
1334                                  * cause nasty problems in the blocking world */
1335                                 s->rwstate=SSL_READING;
1336                                 bio=SSL_get_rbio(s);
1337                                 BIO_clear_retry_flags(bio);
1338                                 BIO_set_retry_read(bio);
1339                                 return(-1);
1340                                 }
1341                         }
1342                 goto start;
1343                 }
1344
1345         switch (rr->type)
1346                 {
1347         default:
1348 #ifndef OPENSSL_NO_TLS
1349                 /* TLS up to v1.1 just ignores unknown message types:
1350                  * TLS v1.2 give an unexpected message alert.
1351                  */
1352                 if (s->version >= TLS1_VERSION && s->version <= TLS1_1_VERSION)
1353                         {
1354                         rr->length = 0;
1355                         goto start;
1356                         }
1357 #endif
1358                 al=SSL_AD_UNEXPECTED_MESSAGE;
1359                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1360                 goto f_err;
1361         case SSL3_RT_CHANGE_CIPHER_SPEC:
1362         case SSL3_RT_ALERT:
1363         case SSL3_RT_HANDSHAKE:
1364                 /* we already handled all of these, with the possible exception
1365                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1366                  * should not happen when type != rr->type */
1367                 al=SSL_AD_UNEXPECTED_MESSAGE;
1368                 SSLerr(SSL_F_SSL3_READ_BYTES,ERR_R_INTERNAL_ERROR);
1369                 goto f_err;
1370         case SSL3_RT_APPLICATION_DATA:
1371                 /* At this point, we were expecting handshake data,
1372                  * but have application data.  If the library was
1373                  * running inside ssl3_read() (i.e. in_read_app_data
1374                  * is set) and it makes sense to read application data
1375                  * at this point (session renegotiation not yet started),
1376                  * we will indulge it.
1377                  */
1378                 if (s->s3->in_read_app_data &&
1379                         (s->s3->total_renegotiations != 0) &&
1380                         ((
1381                                 (s->state & SSL_ST_CONNECT) &&
1382                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1383                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1384                                 ) || (
1385                                         (s->state & SSL_ST_ACCEPT) &&
1386                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1387                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1388                                         )
1389                                 ))
1390                         {
1391                         s->s3->in_read_app_data=2;
1392                         return(-1);
1393                         }
1394                 else
1395                         {
1396                         al=SSL_AD_UNEXPECTED_MESSAGE;
1397                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1398                         goto f_err;
1399                         }
1400                 }
1401         /* not reached */
1402
1403 f_err:
1404         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1405 err:
1406         return(-1);
1407         }
1408
1409 int ssl3_do_change_cipher_spec(SSL *s)
1410         {
1411         int i;
1412         const char *sender;
1413         int slen;
1414
1415         if (s->state & SSL_ST_ACCEPT)
1416                 i=SSL3_CHANGE_CIPHER_SERVER_READ;
1417         else
1418                 i=SSL3_CHANGE_CIPHER_CLIENT_READ;
1419
1420         if (s->s3->tmp.key_block == NULL)
1421                 {
1422                 if (s->session == NULL) 
1423                         {
1424                         /* might happen if dtls1_read_bytes() calls this */
1425                         SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_CCS_RECEIVED_EARLY);
1426                         return (0);
1427                         }
1428
1429                 s->session->cipher=s->s3->tmp.new_cipher;
1430                 if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
1431                 }
1432
1433         if (!s->method->ssl3_enc->change_cipher_state(s,i))
1434                 return(0);
1435
1436         /* we have to record the message digest at
1437          * this point so we can get it before we read
1438          * the finished message */
1439         if (s->state & SSL_ST_CONNECT)
1440                 {
1441                 sender=s->method->ssl3_enc->server_finished_label;
1442                 slen=s->method->ssl3_enc->server_finished_label_len;
1443                 }
1444         else
1445                 {
1446                 sender=s->method->ssl3_enc->client_finished_label;
1447                 slen=s->method->ssl3_enc->client_finished_label_len;
1448                 }
1449
1450         s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
1451                 sender,slen,s->s3->tmp.peer_finish_md);
1452
1453         return(1);
1454         }
1455
1456 int ssl3_send_alert(SSL *s, int level, int desc)
1457         {
1458         /* Map tls/ssl alert value to correct one */
1459         desc=s->method->ssl3_enc->alert_value(desc);
1460         if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION)
1461                 desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have protocol_version alerts */
1462         if (desc < 0) return -1;
1463         /* If a fatal one, remove from cache */
1464         if ((level == 2) && (s->session != NULL))
1465                 SSL_CTX_remove_session(s->ctx,s->session);
1466
1467         s->s3->alert_dispatch=1;
1468         s->s3->send_alert[0]=level;
1469         s->s3->send_alert[1]=desc;
1470         if (s->s3->wbuf.left == 0) /* data still being written out? */
1471                 return s->method->ssl_dispatch_alert(s);
1472         /* else data is still being written out, we will get written
1473          * some time in the future */
1474         return -1;
1475         }
1476
1477 int ssl3_dispatch_alert(SSL *s)
1478         {
1479         int i,j;
1480         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1481
1482         s->s3->alert_dispatch=0;
1483         i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0);
1484         if (i <= 0)
1485                 {
1486                 s->s3->alert_dispatch=1;
1487                 }
1488         else
1489                 {
1490                 /* Alert sent to BIO.  If it is important, flush it now.
1491                  * If the message does not get sent due to non-blocking IO,
1492                  * we will not worry too much. */
1493                 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1494                         (void)BIO_flush(s->wbio);
1495
1496                 if (s->msg_callback)
1497                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s, s->msg_callback_arg);
1498
1499                 if (s->info_callback != NULL)
1500                         cb=s->info_callback;
1501                 else if (s->ctx->info_callback != NULL)
1502                         cb=s->ctx->info_callback;
1503
1504                 if (cb != NULL)
1505                         {
1506                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1507                         cb(s,SSL_CB_WRITE_ALERT,j);
1508                         }
1509                 }
1510         return(i);
1511         }