da63e50aed237fc5a51621fcce3a6da6fca99b28
[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                                 if (len+left == 0)
252                                         ssl3_release_read_buffer(s);
253                         return(i);
254                         }
255                 left+=i;
256                 /* reads should *never* span multiple packets for DTLS because
257                  * the underlying transport protocol is message oriented as opposed
258                  * to byte oriented as in the TLS case. */
259                 if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
260                         {
261                         if (n > left)
262                                 n = left; /* makes the while condition false */
263                         }
264                 }
265
266         /* done reading, now the book-keeping */
267         rb->offset += n;
268         rb->left = left - n;
269         s->packet_length += n;
270         s->rwstate=SSL_NOTHING;
271         return(n);
272         }
273
274 /* Call this to get a new input record.
275  * It will return <= 0 if more data is needed, normally due to an error
276  * or non-blocking IO.
277  * When it finishes, one packet has been decoded and can be found in
278  * ssl->s3->rrec.type    - is the type of record
279  * ssl->s3->rrec.data,   - data
280  * ssl->s3->rrec.length, - number of bytes
281  */
282 /* used only by ssl3_read_bytes */
283 static int ssl3_get_record(SSL *s)
284         {
285         int ssl_major,ssl_minor,al;
286         int enc_err,n,i,ret= -1;
287         SSL3_RECORD *rr;
288         SSL_SESSION *sess;
289         unsigned char *p;
290         unsigned char md[EVP_MAX_MD_SIZE];
291         short version;
292         int mac_size;
293         int clear=0;
294         size_t extra;
295         int decryption_failed_or_bad_record_mac = 0;
296         unsigned char *mac = NULL;
297
298         rr= &(s->s3->rrec);
299         sess=s->session;
300
301         if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
302                 extra=SSL3_RT_MAX_EXTRA;
303         else
304                 extra=0;
305         if (extra && !s->s3->init_extra)
306                 {
307                 /* An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
308                  * set after ssl3_setup_buffers() was done */
309                 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
310                 return -1;
311                 }
312
313 again:
314         /* check if we have the header */
315         if (    (s->rstate != SSL_ST_READ_BODY) ||
316                 (s->packet_length < SSL3_RT_HEADER_LENGTH)) 
317                 {
318                 n=ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
319                 if (n <= 0) return(n); /* error or non-blocking */
320                 s->rstate=SSL_ST_READ_BODY;
321
322                 p=s->packet;
323
324                 /* Pull apart the header into the SSL3_RECORD */
325                 rr->type= *(p++);
326                 ssl_major= *(p++);
327                 ssl_minor= *(p++);
328                 version=(ssl_major<<8)|ssl_minor;
329                 n2s(p,rr->length);
330 #if 0
331 fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length);
332 #endif
333 fprintf(stderr, "RX version %x, Expecting %x\n", version, s->version);
334                 /* Lets check version */
335                 if (!s->first_packet)
336                         {
337                         if (version != s->version)
338                                 {
339                                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
340                                 /* Send back error using their
341                                  * version number :-) */
342                                 s->version=version;
343                                 al=SSL_AD_PROTOCOL_VERSION;
344                                 goto f_err;
345                                 }
346                         }
347
348                 if ((version>>8) != SSL3_VERSION_MAJOR)
349                         {
350                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
351                         goto err;
352                         }
353
354                 if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH)
355                         {
356                         al=SSL_AD_RECORD_OVERFLOW;
357                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
358                         goto f_err;
359                         }
360
361                 /* now s->rstate == SSL_ST_READ_BODY */
362                 }
363
364         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
365
366         if (rr->length > s->packet_length-SSL3_RT_HEADER_LENGTH)
367                 {
368                 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
369                 i=rr->length;
370                 n=ssl3_read_n(s,i,i,1);
371                 if (n <= 0) return(n); /* error or non-blocking io */
372                 /* now n == rr->length,
373                  * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */
374                 }
375
376         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
377
378         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
379          * and we have that many bytes in s->packet
380          */
381         rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);
382
383         /* ok, we can now read from 's->packet' data into 'rr'
384          * rr->input points at rr->length bytes, which
385          * need to be copied into rr->data by either
386          * the decryption or by the decompression
387          * When the data is 'copied' into the rr->data buffer,
388          * rr->input will be pointed at the new buffer */ 
389
390         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
391          * rr->length bytes of encrypted compressed stuff. */
392
393         /* check is not needed I believe */
394         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
395                 {
396                 al=SSL_AD_RECORD_OVERFLOW;
397                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
398                 goto f_err;
399                 }
400
401         /* decrypt in place in 'rr->input' */
402         rr->data=rr->input;
403
404         enc_err = s->method->ssl3_enc->enc(s,0);
405         if (enc_err <= 0)
406                 {
407                 if (enc_err == 0)
408                         /* SSLerr() and ssl3_send_alert() have been called */
409                         goto err;
410
411                 /* Otherwise enc_err == -1, which indicates bad padding
412                  * (rec->length has not been changed in this case).
413                  * To minimize information leaked via timing, we will perform
414                  * the MAC computation anyway. */
415                 decryption_failed_or_bad_record_mac = 1;
416                 }
417
418 #ifdef TLS_DEBUG
419 printf("dec %d\n",rr->length);
420 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
421 printf("\n");
422 #endif
423
424         /* r->length is now the compressed data plus mac */
425         if (    (sess == NULL) ||
426                 (s->enc_read_ctx == NULL) ||
427                 (EVP_MD_CTX_md(s->read_hash) == NULL))
428                 clear=1;
429
430         if (!clear)
431                 {
432                 /* !clear => s->read_hash != NULL => mac_size != -1 */
433                 mac_size=EVP_MD_CTX_size(s->read_hash);
434                 OPENSSL_assert(mac_size >= 0);
435
436                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
437                         {
438 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
439                         al=SSL_AD_RECORD_OVERFLOW;
440                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
441                         goto f_err;
442 #else
443                         decryption_failed_or_bad_record_mac = 1;
444 #endif                  
445                         }
446                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
447                 if (rr->length >= (unsigned int)mac_size)
448                         {
449                         rr->length -= mac_size;
450                         mac = &rr->data[rr->length];
451                         }
452                 else
453                         {
454                         /* record (minus padding) is too short to contain a MAC */
455 #if 0 /* OK only for stream ciphers */
456                         al=SSL_AD_DECODE_ERROR;
457                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
458                         goto f_err;
459 #else
460                         decryption_failed_or_bad_record_mac = 1;
461                         rr->length = 0;
462 #endif
463                         }
464                 i=s->method->ssl3_enc->mac(s,md,0);
465                 if (i < 0 || mac == NULL || memcmp(md, mac, (size_t)mac_size) != 0)
466                         {
467                         decryption_failed_or_bad_record_mac = 1;
468                         }
469                 }
470
471         if (decryption_failed_or_bad_record_mac)
472                 {
473                 /* A separate 'decryption_failed' alert was introduced with TLS 1.0,
474                  * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
475                  * failure is directly visible from the ciphertext anyway,
476                  * we should not reveal which kind of error occured -- this
477                  * might become visible to an attacker (e.g. via a logfile) */
478                 al=SSL_AD_BAD_RECORD_MAC;
479                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
480                 goto f_err;
481                 }
482
483         /* r->length is now just compressed */
484         if (s->expand != NULL)
485                 {
486                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
487                         {
488                         al=SSL_AD_RECORD_OVERFLOW;
489                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
490                         goto f_err;
491                         }
492                 if (!ssl3_do_uncompress(s))
493                         {
494                         al=SSL_AD_DECOMPRESSION_FAILURE;
495                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
496                         goto f_err;
497                         }
498                 }
499
500         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH+extra)
501                 {
502                 al=SSL_AD_RECORD_OVERFLOW;
503                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
504                 goto f_err;
505                 }
506
507         rr->off=0;
508         /* So at this point the following is true
509          * ssl->s3->rrec.type   is the type of record
510          * ssl->s3->rrec.length == number of bytes in record
511          * ssl->s3->rrec.off    == offset to first valid byte
512          * ssl->s3->rrec.data   == where to take bytes from, increment
513          *                         after use :-).
514          */
515
516         /* we have pulled in a full packet so zero things */
517         s->packet_length=0;
518
519         /* just read a 0 length packet */
520         if (rr->length == 0) goto again;
521
522 #if 0
523 fprintf(stderr, "Ultimate Record type=%d, Length=%d\n", rr->type, rr->length);
524 #endif
525
526         return(1);
527
528 f_err:
529         ssl3_send_alert(s,SSL3_AL_FATAL,al);
530 err:
531         return(ret);
532         }
533
534 int ssl3_do_uncompress(SSL *ssl)
535         {
536 #ifndef OPENSSL_NO_COMP
537         int i;
538         SSL3_RECORD *rr;
539
540         rr= &(ssl->s3->rrec);
541         i=COMP_expand_block(ssl->expand,rr->comp,
542                 SSL3_RT_MAX_PLAIN_LENGTH,rr->data,(int)rr->length);
543         if (i < 0)
544                 return(0);
545         else
546                 rr->length=i;
547         rr->data=rr->comp;
548 #endif
549         return(1);
550         }
551
552 int ssl3_do_compress(SSL *ssl)
553         {
554 #ifndef OPENSSL_NO_COMP
555         int i;
556         SSL3_RECORD *wr;
557
558         wr= &(ssl->s3->wrec);
559         i=COMP_compress_block(ssl->compress,wr->data,
560                 SSL3_RT_MAX_COMPRESSED_LENGTH,
561                 wr->input,(int)wr->length);
562         if (i < 0)
563                 return(0);
564         else
565                 wr->length=i;
566
567         wr->input=wr->data;
568 #endif
569         return(1);
570         }
571
572 /* Call this to write data in records of type 'type'
573  * It will return <= 0 if not all data has been sent or non-blocking IO.
574  */
575 int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
576         {
577         const unsigned char *buf=buf_;
578         unsigned int tot,n,nw;
579         int i;
580
581         s->rwstate=SSL_NOTHING;
582         tot=s->s3->wnum;
583         s->s3->wnum=0;
584
585         if (SSL_in_init(s) && !s->in_handshake)
586                 {
587                 i=s->handshake_func(s);
588                 if (i < 0) return(i);
589                 if (i == 0)
590                         {
591                         SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
592                         return -1;
593                         }
594                 }
595
596         n=(len-tot);
597         for (;;)
598                 {
599                 if (n > s->max_send_fragment)
600                         nw=s->max_send_fragment;
601                 else
602                         nw=n;
603
604                 i=do_ssl3_write(s, type, &(buf[tot]), nw, 0);
605                 if (i <= 0)
606                         {
607                         s->s3->wnum=tot;
608                         return i;
609                         }
610
611                 if ((i == (int)n) ||
612                         (type == SSL3_RT_APPLICATION_DATA &&
613                          (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
614                         {
615                         /* next chunk of data should get another prepended empty fragment
616                          * in ciphersuites with known-IV weakness: */
617                         s->s3->empty_fragment_done = 0;
618                         
619                         return tot+i;
620                         }
621
622                 n-=i;
623                 tot+=i;
624                 }
625         }
626
627 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
628                          unsigned int len, int create_empty_fragment)
629         {
630         unsigned char *p,*plen;
631         int i,mac_size,clear=0;
632         int prefix_len=0;
633         int eivlen;
634         long align=0;
635         SSL3_RECORD *wr;
636         SSL3_BUFFER *wb=&(s->s3->wbuf);
637         SSL_SESSION *sess;
638
639         if (wb->buf == NULL)
640                 if (!ssl3_setup_write_buffer(s))
641                         return -1;
642
643         /* first check if there is a SSL3_BUFFER still being written
644          * out.  This will happen with non blocking IO */
645         if (wb->left != 0)
646                 return(ssl3_write_pending(s,type,buf,len));
647
648         /* If we have an alert to send, lets send it */
649         if (s->s3->alert_dispatch)
650                 {
651                 i=s->method->ssl_dispatch_alert(s);
652                 if (i <= 0)
653                         return(i);
654                 /* if it went, fall through and send more stuff */
655                 }
656
657         if (len == 0 && !create_empty_fragment)
658                 return 0;
659
660         wr= &(s->s3->wrec);
661         sess=s->session;
662
663         if (    (sess == NULL) ||
664                 (s->enc_write_ctx == NULL) ||
665                 (EVP_MD_CTX_md(s->write_hash) == NULL))
666                 clear=1;
667
668         if (clear)
669                 mac_size=0;
670         else
671                 {
672                 mac_size=EVP_MD_CTX_size(s->write_hash);
673                 if (mac_size < 0)
674                         goto err;
675                 }
676
677         /* 'create_empty_fragment' is true only when this function calls itself */
678         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done)
679                 {
680                 /* countermeasure against known-IV weakness in CBC ciphersuites
681                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
682
683                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
684                         {
685                         /* recursive function call with 'create_empty_fragment' set;
686                          * this prepares and buffers the data for an empty fragment
687                          * (these 'prefix_len' bytes are sent out later
688                          * together with the actual payload) */
689                         prefix_len = do_ssl3_write(s, type, buf, 0, 1);
690                         if (prefix_len <= 0)
691                                 goto err;
692
693                         if (prefix_len >
694                 (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD))
695                                 {
696                                 /* insufficient space */
697                                 SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
698                                 goto err;
699                                 }
700                         }
701                 
702                 s->s3->empty_fragment_done = 1;
703                 }
704
705         if (create_empty_fragment)
706                 {
707 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
708                 /* extra fragment would be couple of cipher blocks,
709                  * which would be multiple of SSL3_ALIGN_PAYLOAD, so
710                  * if we want to align the real payload, then we can
711                  * just pretent we simply have two headers. */
712                 align = (long)wb->buf + 2*SSL3_RT_HEADER_LENGTH;
713                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
714 #endif
715                 p = wb->buf + align;
716                 wb->offset  = align;
717                 }
718         else if (prefix_len)
719                 {
720                 p = wb->buf + wb->offset + prefix_len;
721                 }
722         else
723                 {
724 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
725                 align = (long)wb->buf + SSL3_RT_HEADER_LENGTH;
726                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
727 #endif
728                 p = wb->buf + align;
729                 wb->offset  = align;
730                 }
731
732         /* write the header */
733
734         *(p++)=type&0xff;
735         wr->type=type;
736
737         *(p++)=(s->version>>8);
738         *(p++)=s->version&0xff;
739 fprintf(stderr, "Wrote version %x\n", s->version);
740         /* field where we are to write out packet length */
741         plen=p; 
742         p+=2;
743         /* Explicit IV length, block ciphers and TLS version 1.1 or later */
744         if (s->enc_write_ctx && s->version >= TLS1_1_VERSION)
745                 {
746                 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
747                 if (eivlen <= 1)
748                         eivlen = 0;
749                 }
750         else 
751                 eivlen = 0;
752
753         /* lets setup the record stuff. */
754         wr->data=p + eivlen;
755         wr->length=(int)len;
756         wr->input=(unsigned char *)buf;
757
758         /* we now 'read' from wr->input, wr->length bytes into
759          * wr->data */
760
761         /* first we compress */
762         if (s->compress != NULL)
763                 {
764                 if (!ssl3_do_compress(s))
765                         {
766                         SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
767                         goto err;
768                         }
769                 }
770         else
771                 {
772                 memcpy(wr->data,wr->input,wr->length);
773                 wr->input=wr->data;
774                 }
775
776         /* we should still have the output to wr->data and the input
777          * from wr->input.  Length should be wr->length.
778          * wr->data still points in the wb->buf */
779
780         if (mac_size != 0)
781                 {
782                 if (s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0)
783                         goto err;
784                 wr->length+=mac_size;
785                 }
786
787         wr->input=p;
788         wr->data=p;
789
790         if (eivlen)
791                 {
792         /*      if (RAND_pseudo_bytes(p, eivlen) <= 0)
793                         goto err; */
794                 wr->length += eivlen;
795                 }
796
797         /* ssl3_enc can only have an error on read */
798         s->method->ssl3_enc->enc(s,1);
799
800         /* record length after mac and block padding */
801         s2n(wr->length,plen);
802
803         /* we should now have
804          * wr->data pointing to the encrypted data, which is
805          * wr->length long */
806         wr->type=type; /* not needed but helps for debugging */
807         wr->length+=SSL3_RT_HEADER_LENGTH;
808
809         if (create_empty_fragment)
810                 {
811                 /* we are in a recursive call;
812                  * just return the length, don't write out anything here
813                  */
814                 return wr->length;
815                 }
816
817         /* now let's set up wb */
818         wb->left = prefix_len + wr->length;
819
820         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
821         s->s3->wpend_tot=len;
822         s->s3->wpend_buf=buf;
823         s->s3->wpend_type=type;
824         s->s3->wpend_ret=len;
825
826         /* we now just need to write the buffer */
827         return ssl3_write_pending(s,type,buf,len);
828 err:
829         return -1;
830         }
831
832 /* if s->s3->wbuf.left != 0, we need to call this */
833 int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
834         unsigned int len)
835         {
836         int i;
837         SSL3_BUFFER *wb=&(s->s3->wbuf);
838
839 /* XXXX */
840         if ((s->s3->wpend_tot > (int)len)
841                 || ((s->s3->wpend_buf != buf) &&
842                         !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER))
843                 || (s->s3->wpend_type != type))
844                 {
845                 SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
846                 return(-1);
847                 }
848
849         for (;;)
850                 {
851                 clear_sys_error();
852                 if (s->wbio != NULL)
853                         {
854                         s->rwstate=SSL_WRITING;
855                         i=BIO_write(s->wbio,
856                                 (char *)&(wb->buf[wb->offset]),
857                                 (unsigned int)wb->left);
858                         }
859                 else
860                         {
861                         SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
862                         i= -1;
863                         }
864                 if (i == wb->left)
865                         {
866                         wb->left=0;
867                         wb->offset+=i;
868                         if (s->mode & SSL_MODE_RELEASE_BUFFERS)
869                                 ssl3_release_write_buffer(s);
870                         s->rwstate=SSL_NOTHING;
871                         return(s->s3->wpend_ret);
872                         }
873                 else if (i <= 0) {
874                         if (s->version == DTLS1_VERSION ||
875                             s->version == DTLS1_BAD_VER) {
876                                 /* For DTLS, just drop it. That's kind of the whole
877                                    point in using a datagram service */
878                                 wb->left = 0;
879                         }
880                         return(i);
881                 }
882                 wb->offset+=i;
883                 wb->left-=i;
884                 }
885         }
886
887 /* Return up to 'len' payload bytes received in 'type' records.
888  * 'type' is one of the following:
889  *
890  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
891  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
892  *   -  0 (during a shutdown, no data has to be returned)
893  *
894  * If we don't have stored data to work from, read a SSL/TLS record first
895  * (possibly multiple records if we still don't have anything to return).
896  *
897  * This function must handle any surprises the peer may have for us, such as
898  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
899  * a surprise, but handled as if it were), or renegotiation requests.
900  * Also if record payloads contain fragments too small to process, we store
901  * them until there is enough for the respective protocol (the record protocol
902  * may use arbitrary fragmentation and even interleaving):
903  *     Change cipher spec protocol
904  *             just 1 byte needed, no need for keeping anything stored
905  *     Alert protocol
906  *             2 bytes needed (AlertLevel, AlertDescription)
907  *     Handshake protocol
908  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
909  *             to detect unexpected Client Hello and Hello Request messages
910  *             here, anything else is handled by higher layers
911  *     Application data protocol
912  *             none of our business
913  */
914 int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
915         {
916         int al,i,j,ret;
917         unsigned int n;
918         SSL3_RECORD *rr;
919         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
920
921         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
922                 if (!ssl3_setup_read_buffer(s))
923                         return(-1);
924
925         if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE) && type) ||
926             (peek && (type != SSL3_RT_APPLICATION_DATA)))
927                 {
928                 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
929                 return -1;
930                 }
931
932         if ((type == SSL3_RT_HANDSHAKE) && (s->s3->handshake_fragment_len > 0))
933                 /* (partially) satisfy request from storage */
934                 {
935                 unsigned char *src = s->s3->handshake_fragment;
936                 unsigned char *dst = buf;
937                 unsigned int k;
938
939                 /* peek == 0 */
940                 n = 0;
941                 while ((len > 0) && (s->s3->handshake_fragment_len > 0))
942                         {
943                         *dst++ = *src++;
944                         len--; s->s3->handshake_fragment_len--;
945                         n++;
946                         }
947                 /* move any remaining fragment bytes: */
948                 for (k = 0; k < s->s3->handshake_fragment_len; k++)
949                         s->s3->handshake_fragment[k] = *src++;
950                 return n;
951         }
952
953         /* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
954
955         if (!s->in_handshake && SSL_in_init(s))
956                 {
957                 /* type == SSL3_RT_APPLICATION_DATA */
958                 i=s->handshake_func(s);
959                 if (i < 0) return(i);
960                 if (i == 0)
961                         {
962                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
963                         return(-1);
964                         }
965                 }
966 start:
967         s->rwstate=SSL_NOTHING;
968
969         /* s->s3->rrec.type         - is the type of record
970          * s->s3->rrec.data,    - data
971          * s->s3->rrec.off,     - offset into 'data' for next read
972          * s->s3->rrec.length,  - number of bytes. */
973         rr = &(s->s3->rrec);
974
975         /* get new packet if necessary */
976         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
977                 {
978                 ret=ssl3_get_record(s);
979                 if (ret <= 0) return(ret);
980                 }
981
982         /* we now have a packet which can be read and processed */
983
984         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
985                                        * reset by ssl3_get_finished */
986                 && (rr->type != SSL3_RT_HANDSHAKE))
987                 {
988                 al=SSL_AD_UNEXPECTED_MESSAGE;
989                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
990                 goto f_err;
991                 }
992
993         /* If the other end has shut down, throw anything we read away
994          * (even in 'peek' mode) */
995         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
996                 {
997                 rr->length=0;
998                 s->rwstate=SSL_NOTHING;
999                 return(0);
1000                 }
1001
1002
1003         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
1004                 {
1005                 /* make sure that we are not getting application data when we
1006                  * are doing a handshake for the first time */
1007                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
1008                         (s->enc_read_ctx == NULL))
1009                         {
1010                         al=SSL_AD_UNEXPECTED_MESSAGE;
1011                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
1012                         goto f_err;
1013                         }
1014
1015                 if (len <= 0) return(len);
1016
1017                 if ((unsigned int)len > rr->length)
1018                         n = rr->length;
1019                 else
1020                         n = (unsigned int)len;
1021
1022                 memcpy(buf,&(rr->data[rr->off]),n);
1023                 if (!peek)
1024                         {
1025                         rr->length-=n;
1026                         rr->off+=n;
1027                         if (rr->length == 0)
1028                                 {
1029                                 s->rstate=SSL_ST_READ_HEADER;
1030                                 rr->off=0;
1031                                 if (s->mode & SSL_MODE_RELEASE_BUFFERS)
1032                                         ssl3_release_read_buffer(s);
1033                                 }
1034                         }
1035                 return(n);
1036                 }
1037
1038
1039         /* If we get here, then type != rr->type; if we have a handshake
1040          * message, then it was unexpected (Hello Request or Client Hello). */
1041
1042         /* In case of record types for which we have 'fragment' storage,
1043          * fill that so that we can process the data at a fixed place.
1044          */
1045                 {
1046                 unsigned int dest_maxlen = 0;
1047                 unsigned char *dest = NULL;
1048                 unsigned int *dest_len = NULL;
1049
1050                 if (rr->type == SSL3_RT_HANDSHAKE)
1051                         {
1052                         dest_maxlen = sizeof s->s3->handshake_fragment;
1053                         dest = s->s3->handshake_fragment;
1054                         dest_len = &s->s3->handshake_fragment_len;
1055                         }
1056                 else if (rr->type == SSL3_RT_ALERT)
1057                         {
1058                         dest_maxlen = sizeof s->s3->alert_fragment;
1059                         dest = s->s3->alert_fragment;
1060                         dest_len = &s->s3->alert_fragment_len;
1061                         }
1062
1063                 if (dest_maxlen > 0)
1064                         {
1065                         n = dest_maxlen - *dest_len; /* available space in 'dest' */
1066                         if (rr->length < n)
1067                                 n = rr->length; /* available bytes */
1068
1069                         /* now move 'n' bytes: */
1070                         while (n-- > 0)
1071                                 {
1072                                 dest[(*dest_len)++] = rr->data[rr->off++];
1073                                 rr->length--;
1074                                 }
1075
1076                         if (*dest_len < dest_maxlen)
1077                                 goto start; /* fragment was too small */
1078                         }
1079                 }
1080
1081         /* s->s3->handshake_fragment_len == 4  iff  rr->type == SSL3_RT_HANDSHAKE;
1082          * s->s3->alert_fragment_len == 2      iff  rr->type == SSL3_RT_ALERT.
1083          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1084
1085         /* If we are a client, check for an incoming 'Hello Request': */
1086         if ((!s->server) &&
1087                 (s->s3->handshake_fragment_len >= 4) &&
1088                 (s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1089                 (s->session != NULL) && (s->session->cipher != NULL))
1090                 {
1091                 s->s3->handshake_fragment_len = 0;
1092
1093                 if ((s->s3->handshake_fragment[1] != 0) ||
1094                         (s->s3->handshake_fragment[2] != 0) ||
1095                         (s->s3->handshake_fragment[3] != 0))
1096                         {
1097                         al=SSL_AD_DECODE_ERROR;
1098                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1099                         goto f_err;
1100                         }
1101
1102                 if (s->msg_callback)
1103                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->s3->handshake_fragment, 4, s, s->msg_callback_arg);
1104
1105                 if (SSL_is_init_finished(s) &&
1106                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1107                         !s->s3->renegotiate)
1108                         {
1109                         ssl3_renegotiate(s);
1110                         if (ssl3_renegotiate_check(s))
1111                                 {
1112                                 i=s->handshake_func(s);
1113                                 if (i < 0) return(i);
1114                                 if (i == 0)
1115                                         {
1116                                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1117                                         return(-1);
1118                                         }
1119
1120                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1121                                         {
1122                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1123                                                 {
1124                                                 BIO *bio;
1125                                                 /* In the case where we try to read application data,
1126                                                  * but we trigger an SSL handshake, we return -1 with
1127                                                  * the retry option set.  Otherwise renegotiation may
1128                                                  * cause nasty problems in the blocking world */
1129                                                 s->rwstate=SSL_READING;
1130                                                 bio=SSL_get_rbio(s);
1131                                                 BIO_clear_retry_flags(bio);
1132                                                 BIO_set_retry_read(bio);
1133                                                 return(-1);
1134                                                 }
1135                                         }
1136                                 }
1137                         }
1138                 /* we either finished a handshake or ignored the request,
1139                  * now try again to obtain the (application) data we were asked for */
1140                 goto start;
1141                 }
1142         /* If we are a server and get a client hello when renegotiation isn't
1143          * allowed send back a no renegotiation alert and carry on.
1144          * WARNING: experimental code, needs reviewing (steve)
1145          */
1146         if (s->server &&
1147                 SSL_is_init_finished(s) &&
1148                 !s->s3->send_connection_binding &&
1149                 (s->version > SSL3_VERSION) &&
1150                 (s->s3->handshake_fragment_len >= 4) &&
1151                 (s->s3->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) &&
1152                 (s->session != NULL) && (s->session->cipher != NULL) &&
1153                 !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
1154                 
1155                 {
1156                 /*s->s3->handshake_fragment_len = 0;*/
1157                 rr->length = 0;
1158                 ssl3_send_alert(s,SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
1159                 goto start;
1160                 }
1161         if (s->s3->alert_fragment_len >= 2)
1162                 {
1163                 int alert_level = s->s3->alert_fragment[0];
1164                 int alert_descr = s->s3->alert_fragment[1];
1165
1166                 s->s3->alert_fragment_len = 0;
1167
1168                 if (s->msg_callback)
1169                         s->msg_callback(0, s->version, SSL3_RT_ALERT, s->s3->alert_fragment, 2, s, s->msg_callback_arg);
1170
1171                 if (s->info_callback != NULL)
1172                         cb=s->info_callback;
1173                 else if (s->ctx->info_callback != NULL)
1174                         cb=s->ctx->info_callback;
1175
1176                 if (cb != NULL)
1177                         {
1178                         j = (alert_level << 8) | alert_descr;
1179                         cb(s, SSL_CB_READ_ALERT, j);
1180                         }
1181
1182                 if (alert_level == 1) /* warning */
1183                         {
1184                         s->s3->warn_alert = alert_descr;
1185                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1186                                 {
1187                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1188                                 return(0);
1189                                 }
1190                         /* This is a warning but we receive it if we requested
1191                          * renegotiation and the peer denied it. Terminate with
1192                          * a fatal alert because if application tried to
1193                          * renegotiatie it presumably had a good reason and
1194                          * expects it to succeed.
1195                          *
1196                          * In future we might have a renegotiation where we
1197                          * don't care if the peer refused it where we carry on.
1198                          */
1199                         else if (alert_descr == SSL_AD_NO_RENEGOTIATION)
1200                                 {
1201                                 al = SSL_AD_HANDSHAKE_FAILURE;
1202                                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_NO_RENEGOTIATION);
1203                                 goto f_err;
1204                                 }
1205                         }
1206                 else if (alert_level == 2) /* fatal */
1207                         {
1208                         char tmp[16];
1209
1210                         s->rwstate=SSL_NOTHING;
1211                         s->s3->fatal_alert = alert_descr;
1212                         SSLerr(SSL_F_SSL3_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1213                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1214                         ERR_add_error_data(2,"SSL alert number ",tmp);
1215                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1216                         SSL_CTX_remove_session(s->ctx,s->session);
1217                         return(0);
1218                         }
1219                 else
1220                         {
1221                         al=SSL_AD_ILLEGAL_PARAMETER;
1222                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1223                         goto f_err;
1224                         }
1225
1226                 goto start;
1227                 }
1228
1229         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1230                 {
1231                 s->rwstate=SSL_NOTHING;
1232                 rr->length=0;
1233                 return(0);
1234                 }
1235
1236         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1237                 {
1238                 /* 'Change Cipher Spec' is just a single byte, so we know
1239                  * exactly what the record payload has to look like */
1240                 if (    (rr->length != 1) || (rr->off != 0) ||
1241                         (rr->data[0] != SSL3_MT_CCS))
1242                         {
1243                         al=SSL_AD_ILLEGAL_PARAMETER;
1244                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1245                         goto f_err;
1246                         }
1247
1248                 /* Check we have a cipher to change to */
1249                 if (s->s3->tmp.new_cipher == NULL)
1250                         {
1251                         al=SSL_AD_UNEXPECTED_MESSAGE;
1252                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
1253                         goto f_err;
1254                         }
1255
1256                 rr->length=0;
1257
1258                 if (s->msg_callback)
1259                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, s->msg_callback_arg);
1260
1261                 s->s3->change_cipher_spec=1;
1262                 if (!ssl3_do_change_cipher_spec(s))
1263                         goto err;
1264                 else
1265                         goto start;
1266                 }
1267
1268         /* Unexpected handshake message (Client Hello, or protocol violation) */
1269         if ((s->s3->handshake_fragment_len >= 4) &&     !s->in_handshake)
1270                 {
1271                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1272                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1273                         {
1274 #if 0 /* worked only because C operator preferences are not as expected (and
1275        * because this is not really needed for clients except for detecting
1276        * protocol violations): */
1277                         s->state=SSL_ST_BEFORE|(s->server)
1278                                 ?SSL_ST_ACCEPT
1279                                 :SSL_ST_CONNECT;
1280 #else
1281                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1282 #endif
1283                         s->new_session=1;
1284                         }
1285                 i=s->handshake_func(s);
1286                 if (i < 0) return(i);
1287                 if (i == 0)
1288                         {
1289                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1290                         return(-1);
1291                         }
1292
1293                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1294                         {
1295                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1296                                 {
1297                                 BIO *bio;
1298                                 /* In the case where we try to read application data,
1299                                  * but we trigger an SSL handshake, we return -1 with
1300                                  * the retry option set.  Otherwise renegotiation may
1301                                  * cause nasty problems in the blocking world */
1302                                 s->rwstate=SSL_READING;
1303                                 bio=SSL_get_rbio(s);
1304                                 BIO_clear_retry_flags(bio);
1305                                 BIO_set_retry_read(bio);
1306                                 return(-1);
1307                                 }
1308                         }
1309                 goto start;
1310                 }
1311
1312         switch (rr->type)
1313                 {
1314         default:
1315 #ifndef OPENSSL_NO_TLS
1316                 /* TLS just ignores unknown message types */
1317                 if (s->version >= TLS1_VERSION && s->version <= TLS1_1_VERSION)
1318                         {
1319                         rr->length = 0;
1320                         goto start;
1321                         }
1322 #endif
1323                 al=SSL_AD_UNEXPECTED_MESSAGE;
1324                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1325                 goto f_err;
1326         case SSL3_RT_CHANGE_CIPHER_SPEC:
1327         case SSL3_RT_ALERT:
1328         case SSL3_RT_HANDSHAKE:
1329                 /* we already handled all of these, with the possible exception
1330                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1331                  * should not happen when type != rr->type */
1332                 al=SSL_AD_UNEXPECTED_MESSAGE;
1333                 SSLerr(SSL_F_SSL3_READ_BYTES,ERR_R_INTERNAL_ERROR);
1334                 goto f_err;
1335         case SSL3_RT_APPLICATION_DATA:
1336                 /* At this point, we were expecting handshake data,
1337                  * but have application data.  If the library was
1338                  * running inside ssl3_read() (i.e. in_read_app_data
1339                  * is set) and it makes sense to read application data
1340                  * at this point (session renegotiation not yet started),
1341                  * we will indulge it.
1342                  */
1343                 if (s->s3->in_read_app_data &&
1344                         (s->s3->total_renegotiations != 0) &&
1345                         ((
1346                                 (s->state & SSL_ST_CONNECT) &&
1347                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1348                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1349                                 ) || (
1350                                         (s->state & SSL_ST_ACCEPT) &&
1351                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1352                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1353                                         )
1354                                 ))
1355                         {
1356                         s->s3->in_read_app_data=2;
1357                         return(-1);
1358                         }
1359                 else
1360                         {
1361                         al=SSL_AD_UNEXPECTED_MESSAGE;
1362                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1363                         goto f_err;
1364                         }
1365                 }
1366         /* not reached */
1367
1368 f_err:
1369         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1370 err:
1371         return(-1);
1372         }
1373
1374 int ssl3_do_change_cipher_spec(SSL *s)
1375         {
1376         int i;
1377         const char *sender;
1378         int slen;
1379
1380         if (s->state & SSL_ST_ACCEPT)
1381                 i=SSL3_CHANGE_CIPHER_SERVER_READ;
1382         else
1383                 i=SSL3_CHANGE_CIPHER_CLIENT_READ;
1384
1385         if (s->s3->tmp.key_block == NULL)
1386                 {
1387                 if (s->session == NULL) 
1388                         {
1389                         /* might happen if dtls1_read_bytes() calls this */
1390                         SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_CCS_RECEIVED_EARLY);
1391                         return (0);
1392                         }
1393
1394                 s->session->cipher=s->s3->tmp.new_cipher;
1395                 if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
1396                 }
1397
1398         if (!s->method->ssl3_enc->change_cipher_state(s,i))
1399                 return(0);
1400
1401         /* we have to record the message digest at
1402          * this point so we can get it before we read
1403          * the finished message */
1404         if (s->state & SSL_ST_CONNECT)
1405                 {
1406                 sender=s->method->ssl3_enc->server_finished_label;
1407                 slen=s->method->ssl3_enc->server_finished_label_len;
1408                 }
1409         else
1410                 {
1411                 sender=s->method->ssl3_enc->client_finished_label;
1412                 slen=s->method->ssl3_enc->client_finished_label_len;
1413                 }
1414
1415         s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
1416                 sender,slen,s->s3->tmp.peer_finish_md);
1417
1418         return(1);
1419         }
1420
1421 int ssl3_send_alert(SSL *s, int level, int desc)
1422         {
1423         /* Map tls/ssl alert value to correct one */
1424         desc=s->method->ssl3_enc->alert_value(desc);
1425         if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION)
1426                 desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have protocol_version alerts */
1427         if (desc < 0) return -1;
1428         /* If a fatal one, remove from cache */
1429         if ((level == 2) && (s->session != NULL))
1430                 SSL_CTX_remove_session(s->ctx,s->session);
1431
1432         s->s3->alert_dispatch=1;
1433         s->s3->send_alert[0]=level;
1434         s->s3->send_alert[1]=desc;
1435         if (s->s3->wbuf.left == 0) /* data still being written out? */
1436                 return s->method->ssl_dispatch_alert(s);
1437         /* else data is still being written out, we will get written
1438          * some time in the future */
1439         return -1;
1440         }
1441
1442 int ssl3_dispatch_alert(SSL *s)
1443         {
1444         int i,j;
1445         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1446
1447         s->s3->alert_dispatch=0;
1448         i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0);
1449         if (i <= 0)
1450                 {
1451                 s->s3->alert_dispatch=1;
1452                 }
1453         else
1454                 {
1455                 /* Alert sent to BIO.  If it is important, flush it now.
1456                  * If the message does not get sent due to non-blocking IO,
1457                  * we will not worry too much. */
1458                 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1459                         (void)BIO_flush(s->wbio);
1460
1461                 if (s->msg_callback)
1462                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s, s->msg_callback_arg);
1463
1464                 if (s->info_callback != NULL)
1465                         cb=s->info_callback;
1466                 else if (s->ctx->info_callback != NULL)
1467                         cb=s->ctx->info_callback;
1468
1469                 if (cb != NULL)
1470                         {
1471                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1472                         cb(s,SSL_CB_WRITE_ALERT,j);
1473                         }
1474                 }
1475         return(i);
1476         }