b76aabee80e03f53a557644dff2f6c3fdc216c5c
[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) 1998-2001 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 <openssl/evp.h>
116 #include <openssl/buffer.h>
117 #include "ssl_locl.h"
118
119 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
120                          unsigned int len);
121 static int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
122                               unsigned int len);
123 static int ssl3_get_record(SSL *s);
124 static int do_compress(SSL *ssl);
125 static int do_uncompress(SSL *ssl);
126 static int do_change_cipher_spec(SSL *ssl);
127
128 /* used only by ssl3_get_record */
129 static int ssl3_read_n(SSL *s, int n, int max, int extend)
130         {
131         /* If extend == 0, obtain new n-byte packet; if extend == 1, increase
132          * packet by another n bytes.
133          * The packet will be in the sub-array of s->s3->rbuf.buf specified
134          * by s->packet and s->packet_length.
135          * (If s->read_ahead is set, 'max' bytes may be stored in rbuf
136          * [plus s->packet_length bytes if extend == 1].)
137          */
138         int i,off,newb;
139
140         if (!extend)
141                 {
142                 /* start with empty packet ... */
143                 if (s->s3->rbuf.left == 0)
144                         s->s3->rbuf.offset = 0;
145                 s->packet = s->s3->rbuf.buf + s->s3->rbuf.offset;
146                 s->packet_length = 0;
147                 /* ... now we can act as if 'extend' was set */
148                 }
149
150         /* if there is enough in the buffer from a previous read, take some */
151         if (s->s3->rbuf.left >= (int)n)
152                 {
153                 s->packet_length+=n;
154                 s->s3->rbuf.left-=n;
155                 s->s3->rbuf.offset+=n;
156                 return(n);
157                 }
158
159         /* else we need to read more data */
160         if (!s->read_ahead)
161                 max=n;
162
163         {
164                 /* avoid buffer overflow */
165                 int max_max = SSL3_RT_MAX_PACKET_SIZE - s->packet_length;
166                 if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
167                         max_max += SSL3_RT_MAX_EXTRA;
168                 if (max > max_max)
169                         max = max_max;
170         }
171         if (n > max) /* does not happen */
172                 {
173                 SSLerr(SSL_F_SSL3_READ_N,ERR_R_INTERNAL_ERROR);
174                 return -1;
175                 }
176
177         off = s->packet_length;
178         newb = s->s3->rbuf.left;
179         /* Move any available bytes to front of buffer:
180          * 'off' bytes already pointed to by 'packet',
181          * 'newb' extra ones at the end */
182         if (s->packet != s->s3->rbuf.buf)
183                 {
184                 /*  off > 0 */
185                 memmove(s->s3->rbuf.buf, s->packet, off+newb);
186                 s->packet = s->s3->rbuf.buf;
187                 }
188
189         while (newb < n)
190                 {
191                 /* Now we have off+newb bytes at the front of s->s3->rbuf.buf and need
192                  * to read in more until we have off+n (up to off+max if possible) */
193
194                 clear_sys_error();
195                 if (s->rbio != NULL)
196                         {
197                         s->rwstate=SSL_READING;
198                         i=BIO_read(s->rbio,     &(s->s3->rbuf.buf[off+newb]), max-newb);
199                         }
200                 else
201                         {
202                         SSLerr(SSL_F_SSL3_READ_N,SSL_R_READ_BIO_NOT_SET);
203                         i = -1;
204                         }
205
206                 if (i <= 0)
207                         {
208                         s->s3->rbuf.left = newb;
209                         return(i);
210                         }
211                 newb+=i;
212                 }
213
214         /* done reading, now the book-keeping */
215         s->s3->rbuf.offset = off + n;
216         s->s3->rbuf.left = newb - n;
217         s->packet_length += n;
218         s->rwstate=SSL_NOTHING;
219         return(n);
220         }
221
222 /* Call this to get a new input record.
223  * It will return <= 0 if more data is needed, normally due to an error
224  * or non-blocking IO.
225  * When it finishes, one packet has been decoded and can be found in
226  * ssl->s3->rrec.type    - is the type of record
227  * ssl->s3->rrec.data,   - data
228  * ssl->s3->rrec.length, - number of bytes
229  */
230 /* used only by ssl3_read_bytes */
231 static int ssl3_get_record(SSL *s)
232         {
233         int ssl_major,ssl_minor,al;
234         int enc_err,n,i,ret= -1;
235         SSL3_RECORD *rr;
236         SSL_SESSION *sess;
237         unsigned char *p;
238         unsigned char md[EVP_MAX_MD_SIZE];
239         short version;
240         unsigned int mac_size;
241         int clear=0,extra;
242
243         rr= &(s->s3->rrec);
244         sess=s->session;
245
246         if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
247                 extra=SSL3_RT_MAX_EXTRA;
248         else
249                 extra=0;
250
251 again:
252         /* check if we have the header */
253         if (    (s->rstate != SSL_ST_READ_BODY) ||
254                 (s->packet_length < SSL3_RT_HEADER_LENGTH)) 
255                 {
256                 n=ssl3_read_n(s,SSL3_RT_HEADER_LENGTH,
257                         SSL3_RT_MAX_PACKET_SIZE,0);
258                 if (n <= 0) return(n); /* error or non-blocking */
259                 s->rstate=SSL_ST_READ_BODY;
260
261                 p=s->packet;
262
263                 /* Pull apart the header into the SSL3_RECORD */
264                 rr->type= *(p++);
265                 ssl_major= *(p++);
266                 ssl_minor= *(p++);
267                 version=(ssl_major<<8)|ssl_minor;
268                 n2s(p,rr->length);
269
270                 /* Lets check version */
271                 if (s->first_packet)
272                         {
273                         s->first_packet=0;
274                         }
275                 else
276                         {
277                         if (version != s->version)
278                                 {
279                                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
280                                 /* Send back error using their
281                                  * version number :-) */
282                                 s->version=version;
283                                 al=SSL_AD_PROTOCOL_VERSION;
284                                 goto f_err;
285                                 }
286                         }
287
288                 if ((version>>8) != SSL3_VERSION_MAJOR)
289                         {
290                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
291                         goto err;
292                         }
293
294                 if (rr->length > 
295                         (unsigned int)SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
296                         {
297                         al=SSL_AD_RECORD_OVERFLOW;
298                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
299                         goto f_err;
300                         }
301
302                 /* now s->rstate == SSL_ST_READ_BODY */
303                 }
304
305         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
306
307         if (rr->length > (s->packet_length-SSL3_RT_HEADER_LENGTH))
308                 {
309                 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
310                 i=rr->length;
311                 n=ssl3_read_n(s,i,i,1);
312                 if (n <= 0) return(n); /* error or non-blocking io */
313                 /* now n == rr->length,
314                  * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */
315                 }
316
317         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
318
319         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
320          * and we have that many bytes in s->packet
321          */
322         rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);
323
324         /* ok, we can now read from 's->packet' data into 'rr'
325          * rr->input points at rr->length bytes, which
326          * need to be copied into rr->data by either
327          * the decryption or by the decompression
328          * When the data is 'copied' into the rr->data buffer,
329          * rr->input will be pointed at the new buffer */ 
330
331         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
332          * rr->length bytes of encrypted compressed stuff. */
333
334         /* check is not needed I believe */
335         if (rr->length > (unsigned int)SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
336                 {
337                 al=SSL_AD_RECORD_OVERFLOW;
338                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
339                 goto f_err;
340                 }
341
342         /* decrypt in place in 'rr->input' */
343         rr->data=rr->input;
344
345         enc_err = s->method->ssl3_enc->enc(s,0);
346         if (enc_err <= 0)
347                 {
348                 if (enc_err == 0)
349                         /* SSLerr() and ssl3_send_alert() have been called */
350                         goto err;
351
352                 /* otherwise enc_err == -1 */
353                 goto decryption_failed_or_bad_record_mac;
354                 }
355
356 #ifdef TLS_DEBUG
357 printf("dec %d\n",rr->length);
358 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
359 printf("\n");
360 #endif
361
362         /* r->length is now the compressed data plus mac */
363         if (    (sess == NULL) ||
364                 (s->enc_read_ctx == NULL) ||
365                 (s->read_hash == NULL))
366                 clear=1;
367
368         if (!clear)
369                 {
370                 mac_size=EVP_MD_size(s->read_hash);
371
372                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
373                         {
374 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
375                         al=SSL_AD_RECORD_OVERFLOW;
376                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
377                         goto f_err;
378 #else
379                         goto decryption_failed_or_bad_record_mac;
380 #endif                  
381                         }
382                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
383                 if (rr->length < mac_size)
384                         {
385 #if 0 /* OK only for stream ciphers */
386                         al=SSL_AD_DECODE_ERROR;
387                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
388                         goto f_err;
389 #else
390                         goto decryption_failed_or_bad_record_mac;
391 #endif
392                         }
393                 rr->length-=mac_size;
394                 i=s->method->ssl3_enc->mac(s,md,0);
395                 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
396                         {
397                         goto decryption_failed_or_bad_record_mac;
398                         }
399                 }
400
401         /* r->length is now just compressed */
402         if (s->expand != NULL)
403                 {
404                 if (rr->length > 
405                         (unsigned int)SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
406                         {
407                         al=SSL_AD_RECORD_OVERFLOW;
408                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
409                         goto f_err;
410                         }
411                 if (!do_uncompress(s))
412                         {
413                         al=SSL_AD_DECOMPRESSION_FAILURE;
414                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
415                         goto f_err;
416                         }
417                 }
418
419         if (rr->length > (unsigned int)SSL3_RT_MAX_PLAIN_LENGTH+extra)
420                 {
421                 al=SSL_AD_RECORD_OVERFLOW;
422                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
423                 goto f_err;
424                 }
425
426         rr->off=0;
427         /* So at this point the following is true
428          * ssl->s3->rrec.type   is the type of record
429          * ssl->s3->rrec.length == number of bytes in record
430          * ssl->s3->rrec.off    == offset to first valid byte
431          * ssl->s3->rrec.data   == where to take bytes from, increment
432          *                         after use :-).
433          */
434
435         /* we have pulled in a full packet so zero things */
436         s->packet_length=0;
437
438         /* just read a 0 length packet */
439         if (rr->length == 0) goto again;
440
441         return(1);
442
443 decryption_failed_or_bad_record_mac:
444         /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
445          * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
446          * failure is directly visible from the ciphertext anyway,
447          * we should not reveal which kind of error occured -- this
448          * might become visible to an attacker (e.g. via logfile) */
449         al=SSL_AD_BAD_RECORD_MAC;
450         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
451 f_err:
452         ssl3_send_alert(s,SSL3_AL_FATAL,al);
453 err:
454         return(ret);
455         }
456
457 static int do_uncompress(SSL *ssl)
458         {
459         int i;
460         SSL3_RECORD *rr;
461
462         rr= &(ssl->s3->rrec);
463         i=COMP_expand_block(ssl->expand,rr->comp,
464                 SSL3_RT_MAX_PLAIN_LENGTH,rr->data,(int)rr->length);
465         if (i < 0)
466                 return(0);
467         else
468                 rr->length=i;
469         rr->data=rr->comp;
470
471         return(1);
472         }
473
474 static int do_compress(SSL *ssl)
475         {
476         int i;
477         SSL3_RECORD *wr;
478
479         wr= &(ssl->s3->wrec);
480         i=COMP_compress_block(ssl->compress,wr->data,
481                 SSL3_RT_MAX_COMPRESSED_LENGTH,
482                 wr->input,(int)wr->length);
483         if (i < 0)
484                 return(0);
485         else
486                 wr->length=i;
487
488         wr->input=wr->data;
489         return(1);
490         }
491
492 /* Call this to write data in records of type 'type'
493  * It will return <= 0 if not all data has been sent or non-blocking IO.
494  */
495 int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
496         {
497         const unsigned char *buf=buf_;
498         unsigned int tot,n,nw;
499         int i;
500
501         s->rwstate=SSL_NOTHING;
502         tot=s->s3->wnum;
503         s->s3->wnum=0;
504
505         if (SSL_in_init(s) && !s->in_handshake)
506                 {
507                 i=s->handshake_func(s);
508                 if (i < 0) return(i);
509                 if (i == 0)
510                         {
511                         SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
512                         return(-1);
513                         }
514                 }
515
516         n=(len-tot);
517         for (;;)
518                 {
519                 if (n > SSL3_RT_MAX_PLAIN_LENGTH)
520                         nw=SSL3_RT_MAX_PLAIN_LENGTH;
521                 else
522                         nw=n;
523
524                 i=do_ssl3_write(s,type,&(buf[tot]),nw);
525                 if (i <= 0)
526                         {
527                         s->s3->wnum=tot;
528                         return(i);
529                         }
530
531                 if ((i == (int)n) ||
532                         (type == SSL3_RT_APPLICATION_DATA &&
533                          (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
534                         {
535                         return(tot+i);
536                         }
537
538                 n-=i;
539                 tot+=i;
540                 }
541         }
542
543 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
544                          unsigned int len)
545         {
546         unsigned char *p,*plen;
547         int i,mac_size,clear=0;
548         SSL3_RECORD *wr;
549         SSL3_BUFFER *wb;
550         SSL_SESSION *sess;
551
552         /* first check is there is a SSL3_RECORD still being written
553          * out.  This will happen with non blocking IO */
554         if (s->s3->wbuf.left != 0)
555                 return(ssl3_write_pending(s,type,buf,len));
556
557         /* If we have an alert to send, lets send it */
558         if (s->s3->alert_dispatch)
559                 {
560                 i=ssl3_dispatch_alert(s);
561                 if (i <= 0)
562                         return(i);
563                 /* if it went, fall through and send more stuff */
564                 }
565
566         if (len == 0) return(len);
567
568         wr= &(s->s3->wrec);
569         wb= &(s->s3->wbuf);
570         sess=s->session;
571
572         if (    (sess == NULL) ||
573                 (s->enc_write_ctx == NULL) ||
574                 (s->write_hash == NULL))
575                 clear=1;
576
577         if (clear)
578                 mac_size=0;
579         else
580                 mac_size=EVP_MD_size(s->write_hash);
581
582         p=wb->buf;
583
584         /* write the header */
585         *(p++)=type&0xff;
586         wr->type=type;
587
588         *(p++)=(s->version>>8);
589         *(p++)=s->version&0xff;
590
591         /* record where we are to write out packet length */
592         plen=p; 
593         p+=2;
594
595         /* lets setup the record stuff. */
596         wr->data=p;
597         wr->length=(int)len;
598         wr->input=(unsigned char *)buf;
599
600         /* we now 'read' from wr->input, wr->length bytes into
601          * wr->data */
602
603         /* first we compress */
604         if (s->compress != NULL)
605                 {
606                 if (!do_compress(s))
607                         {
608                         SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
609                         goto err;
610                         }
611                 }
612         else
613                 {
614                 memcpy(wr->data,wr->input,wr->length);
615                 wr->input=wr->data;
616                 }
617
618         /* we should still have the output to wr->data and the input
619          * from wr->input.  Length should be wr->length.
620          * wr->data still points in the wb->buf */
621
622         if (mac_size != 0)
623                 {
624                 s->method->ssl3_enc->mac(s,&(p[wr->length]),1);
625                 wr->length+=mac_size;
626                 wr->input=p;
627                 wr->data=p;
628                 }
629
630         /* ssl3_enc can only have an error on read */
631         s->method->ssl3_enc->enc(s,1);
632
633         /* record length after mac and block padding */
634         s2n(wr->length,plen);
635
636         /* we should now have
637          * wr->data pointing to the encrypted data, which is
638          * wr->length long */
639         wr->type=type; /* not needed but helps for debugging */
640         wr->length+=SSL3_RT_HEADER_LENGTH;
641
642         /* Now lets setup wb */
643         wb->left=wr->length;
644         wb->offset=0;
645
646         s->s3->wpend_tot=len;
647         s->s3->wpend_buf=buf;
648         s->s3->wpend_type=type;
649         s->s3->wpend_ret=len;
650
651         /* we now just need to write the buffer */
652         return(ssl3_write_pending(s,type,buf,len));
653 err:
654         return(-1);
655         }
656
657 /* if s->s3->wbuf.left != 0, we need to call this */
658 static int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
659                               unsigned int len)
660         {
661         int i;
662
663 /* XXXX */
664         if ((s->s3->wpend_tot > (int)len)
665                 || ((s->s3->wpend_buf != buf) &&
666                         !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER))
667                 || (s->s3->wpend_type != type))
668                 {
669                 SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
670                 return(-1);
671                 }
672
673         for (;;)
674                 {
675                 clear_sys_error();
676                 if (s->wbio != NULL)
677                         {
678                         s->rwstate=SSL_WRITING;
679                         i=BIO_write(s->wbio,
680                                 (char *)&(s->s3->wbuf.buf[s->s3->wbuf.offset]),
681                                 (unsigned int)s->s3->wbuf.left);
682                         }
683                 else
684                         {
685                         SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
686                         i= -1;
687                         }
688                 if (i == s->s3->wbuf.left)
689                         {
690                         s->s3->wbuf.left=0;
691                         s->rwstate=SSL_NOTHING;
692                         return(s->s3->wpend_ret);
693                         }
694                 else if (i <= 0)
695                         return(i);
696                 s->s3->wbuf.offset+=i;
697                 s->s3->wbuf.left-=i;
698                 }
699         }
700
701 /* Return up to 'len' payload bytes received in 'type' records.
702  * 'type' is one of the following:
703  *
704  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
705  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
706  *   -  0 (during a shutdown, no data has to be returned)
707  *
708  * If we don't have stored data to work from, read a SSL/TLS record first
709  * (possibly multiple records if we still don't have anything to return).
710  *
711  * This function must handle any surprises the peer may have for us, such as
712  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
713  * a surprise, but handled as if it were), or renegotiation requests.
714  * Also if record payloads contain fragments too small to process, we store
715  * them until there is enough for the respective protocol (the record protocol
716  * may use arbitrary fragmentation and even interleaving):
717  *     Change cipher spec protocol
718  *             just 1 byte needed, no need for keeping anything stored
719  *     Alert protocol
720  *             2 bytes needed (AlertLevel, AlertDescription)
721  *     Handshake protocol
722  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
723  *             to detect unexpected Client Hello and Hello Request messages
724  *             here, anything else is handled by higher layers
725  *     Application data protocol
726  *             none of our business
727  */
728 int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
729         {
730         int al,i,j,ret;
731         unsigned int n;
732         SSL3_RECORD *rr;
733         void (*cb)()=NULL;
734
735         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
736                 if (!ssl3_setup_buffers(s))
737                         return(-1);
738
739         if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE) && type) ||
740             (peek && (type != SSL3_RT_APPLICATION_DATA)))
741                 {
742                 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
743                 return -1;
744                 }
745
746         if ((type == SSL3_RT_HANDSHAKE) && (s->s3->handshake_fragment_len > 0))
747                 /* (partially) satisfy request from storage */
748                 {
749                 unsigned char *src = s->s3->handshake_fragment;
750                 unsigned char *dst = buf;
751                 unsigned int k;
752
753                 /* peek == 0 */
754                 n = 0;
755                 while ((len > 0) && (s->s3->handshake_fragment_len > 0))
756                         {
757                         *dst++ = *src++;
758                         len--; s->s3->handshake_fragment_len--;
759                         n++;
760                         }
761                 /* move any remaining fragment bytes: */
762                 for (k = 0; k < s->s3->handshake_fragment_len; k++)
763                         s->s3->handshake_fragment[k] = *src++;
764                 return n;
765         }
766
767         /* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
768
769         if (!s->in_handshake && SSL_in_init(s))
770                 {
771                 /* type == SSL3_RT_APPLICATION_DATA */
772                 i=s->handshake_func(s);
773                 if (i < 0) return(i);
774                 if (i == 0)
775                         {
776                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
777                         return(-1);
778                         }
779                 }
780 start:
781         s->rwstate=SSL_NOTHING;
782
783         /* s->s3->rrec.type         - is the type of record
784          * s->s3->rrec.data,    - data
785          * s->s3->rrec.off,     - offset into 'data' for next read
786          * s->s3->rrec.length,  - number of bytes. */
787         rr = &(s->s3->rrec);
788
789         /* get new packet if necessary */
790         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
791                 {
792                 ret=ssl3_get_record(s);
793                 if (ret <= 0) return(ret);
794                 }
795
796         /* we now have a packet which can be read and processed */
797
798         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
799                                        * reset by ssl3_get_finished */
800                 && (rr->type != SSL3_RT_HANDSHAKE))
801                 {
802                 al=SSL_AD_UNEXPECTED_MESSAGE;
803                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
804                 goto err;
805                 }
806
807         /* If the other end has shut down, throw anything we read away
808          * (even in 'peek' mode) */
809         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
810                 {
811                 rr->length=0;
812                 s->rwstate=SSL_NOTHING;
813                 return(0);
814                 }
815
816
817         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
818                 {
819                 /* make sure that we are not getting application data when we
820                  * are doing a handshake for the first time */
821                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
822                         (s->enc_read_ctx == NULL))
823                         {
824                         al=SSL_AD_UNEXPECTED_MESSAGE;
825                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
826                         goto f_err;
827                         }
828
829                 if (len <= 0) return(len);
830
831                 if ((unsigned int)len > rr->length)
832                         n = rr->length;
833                 else
834                         n = (unsigned int)len;
835
836                 memcpy(buf,&(rr->data[rr->off]),n);
837                 if (!peek)
838                         {
839                         rr->length-=n;
840                         rr->off+=n;
841                         if (rr->length == 0)
842                                 {
843                                 s->rstate=SSL_ST_READ_HEADER;
844                                 rr->off=0;
845                                 }
846                         }
847                 return(n);
848                 }
849
850
851         /* If we get here, then type != rr->type; if we have a handshake
852          * message, then it was unexpected (Hello Request or Client Hello). */
853
854         /* In case of record types for which we have 'fragment' storage,
855          * fill that so that we can process the data at a fixed place.
856          */
857                 {
858                 unsigned int dest_maxlen = 0;
859                 unsigned char *dest = NULL;
860                 unsigned int *dest_len = NULL;
861
862                 if (rr->type == SSL3_RT_HANDSHAKE)
863                         {
864                         dest_maxlen = sizeof s->s3->handshake_fragment;
865                         dest = s->s3->handshake_fragment;
866                         dest_len = &s->s3->handshake_fragment_len;
867                         }
868                 else if (rr->type == SSL3_RT_ALERT)
869                         {
870                         dest_maxlen = sizeof s->s3->alert_fragment;
871                         dest = s->s3->alert_fragment;
872                         dest_len = &s->s3->alert_fragment_len;
873                         }
874
875                 if (dest_maxlen > 0)
876                         {
877                         n = dest_maxlen - *dest_len; /* available space in 'dest' */
878                         if (rr->length < n)
879                                 n = rr->length; /* available bytes */
880
881                         /* now move 'n' bytes: */
882                         while (n-- > 0)
883                                 {
884                                 dest[(*dest_len)++] = rr->data[rr->off++];
885                                 rr->length--;
886                                 }
887
888                         if (*dest_len < dest_maxlen)
889                                 goto start; /* fragment was too small */
890                         }
891                 }
892
893         /* s->s3->handshake_fragment_len == 4  iff  rr->type == SSL3_RT_HANDSHAKE;
894          * s->s3->alert_fragment_len == 2      iff  rr->type == SSL3_RT_ALERT.
895          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
896
897         /* If we are a client, check for an incoming 'Hello Request': */
898         if ((!s->server) &&
899                 (s->s3->handshake_fragment_len >= 4) &&
900                 (s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
901                 (s->session != NULL) && (s->session->cipher != NULL))
902                 {
903                 s->s3->handshake_fragment_len = 0;
904
905                 if ((s->s3->handshake_fragment[1] != 0) ||
906                         (s->s3->handshake_fragment[2] != 0) ||
907                         (s->s3->handshake_fragment[3] != 0))
908                         {
909                         al=SSL_AD_DECODE_ERROR;
910                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
911                         goto err;
912                         }
913
914                 if (SSL_is_init_finished(s) &&
915                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
916                         !s->s3->renegotiate)
917                         {
918                         ssl3_renegotiate(s);
919                         if (ssl3_renegotiate_check(s))
920                                 {
921                                 i=s->handshake_func(s);
922                                 if (i < 0) return(i);
923                                 if (i == 0)
924                                         {
925                                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
926                                         return(-1);
927                                         }
928
929                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
930                                         {
931                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
932                                                 {
933                                                 BIO *bio;
934                                                 /* In the case where we try to read application data,
935                                                  * but we trigger an SSL handshake, we return -1 with
936                                                  * the retry option set.  Otherwise renegotiation may
937                                                  * cause nasty problems in the blocking world */
938                                                 s->rwstate=SSL_READING;
939                                                 bio=SSL_get_rbio(s);
940                                                 BIO_clear_retry_flags(bio);
941                                                 BIO_set_retry_read(bio);
942                                                 return(-1);
943                                                 }
944                                         }
945                                 }
946                         }
947                 /* we either finished a handshake or ignored the request,
948                  * now try again to obtain the (application) data we were asked for */
949                 goto start;
950                 }
951
952         if (s->s3->alert_fragment_len >= 2)
953                 {
954                 int alert_level = s->s3->alert_fragment[0];
955                 int alert_descr = s->s3->alert_fragment[1];
956
957                 s->s3->alert_fragment_len = 0;
958
959                 if (s->info_callback != NULL)
960                         cb=s->info_callback;
961                 else if (s->ctx->info_callback != NULL)
962                         cb=s->ctx->info_callback;
963
964                 if (cb != NULL)
965                         {
966                         j = (alert_level << 8) | alert_descr;
967                         cb(s, SSL_CB_READ_ALERT, j);
968                         }
969
970                 if (alert_level == 1) /* warning */
971                         {
972                         s->s3->warn_alert = alert_descr;
973                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
974                                 {
975                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
976                                 return(0);
977                                 }
978                         }
979                 else if (alert_level == 2) /* fatal */
980                         {
981                         char tmp[16];
982
983                         s->rwstate=SSL_NOTHING;
984                         s->s3->fatal_alert = alert_descr;
985                         SSLerr(SSL_F_SSL3_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
986                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
987                         ERR_add_error_data(2,"SSL alert number ",tmp);
988                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
989                         SSL_CTX_remove_session(s->ctx,s->session);
990                         return(0);
991                         }
992                 else
993                         {
994                         al=SSL_AD_ILLEGAL_PARAMETER;
995                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
996                         goto f_err;
997                         }
998
999                 goto start;
1000                 }
1001
1002         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1003                 {
1004                 s->rwstate=SSL_NOTHING;
1005                 rr->length=0;
1006                 return(0);
1007                 }
1008
1009         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1010                 {
1011                 /* 'Change Cipher Spec' is just a single byte, so we know
1012                  * exactly what the record payload has to look like */
1013                 if (    (rr->length != 1) || (rr->off != 0) ||
1014                         (rr->data[0] != SSL3_MT_CCS))
1015                         {
1016                         i=SSL_AD_ILLEGAL_PARAMETER;
1017                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1018                         goto err;
1019                         }
1020
1021                 rr->length=0;
1022                 s->s3->change_cipher_spec=1;
1023                 if (!do_change_cipher_spec(s))
1024                         goto err;
1025                 else
1026                         goto start;
1027                 }
1028
1029         /* Unexpected handshake message (Client Hello, or protocol violation) */
1030         if ((s->s3->handshake_fragment_len >= 4) &&     !s->in_handshake)
1031                 {
1032                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1033                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1034                         {
1035 #if 0 /* worked only because C operator preferences are not as expected (and
1036        * because this is not really needed for clients except for detecting
1037        * protocol violations): */
1038                         s->state=SSL_ST_BEFORE|(s->server)
1039                                 ?SSL_ST_ACCEPT
1040                                 :SSL_ST_CONNECT;
1041 #else
1042                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1043 #endif
1044                         s->new_session=1;
1045                         }
1046                 i=s->handshake_func(s);
1047                 if (i < 0) return(i);
1048                 if (i == 0)
1049                         {
1050                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1051                         return(-1);
1052                         }
1053
1054                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1055                         {
1056                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1057                                 {
1058                                 BIO *bio;
1059                                 /* In the case where we try to read application data,
1060                                  * but we trigger an SSL handshake, we return -1 with
1061                                  * the retry option set.  Otherwise renegotiation may
1062                                  * cause nasty problems in the blocking world */
1063                                 s->rwstate=SSL_READING;
1064                                 bio=SSL_get_rbio(s);
1065                                 BIO_clear_retry_flags(bio);
1066                                 BIO_set_retry_read(bio);
1067                                 return(-1);
1068                                 }
1069                         }
1070                 goto start;
1071                 }
1072
1073         switch (rr->type)
1074                 {
1075         default:
1076 #ifndef OPENSSL_NO_TLS
1077                 /* TLS just ignores unknown message types */
1078                 if (s->version == TLS1_VERSION)
1079                         {
1080                         goto start;
1081                         }
1082 #endif
1083                 al=SSL_AD_UNEXPECTED_MESSAGE;
1084                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1085                 goto f_err;
1086         case SSL3_RT_CHANGE_CIPHER_SPEC:
1087         case SSL3_RT_ALERT:
1088         case SSL3_RT_HANDSHAKE:
1089                 /* we already handled all of these, with the possible exception
1090                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1091                  * should not happen when type != rr->type */
1092                 al=SSL_AD_UNEXPECTED_MESSAGE;
1093                 SSLerr(SSL_F_SSL3_READ_BYTES,ERR_R_INTERNAL_ERROR);
1094                 goto f_err;
1095         case SSL3_RT_APPLICATION_DATA:
1096                 /* At this point, we were expecting handshake data,
1097                  * but have application data.  If the library was
1098                  * running inside ssl3_read() (i.e. in_read_app_data
1099                  * is set) and it makes sense to read application data
1100                  * at this point (session renegotiation not yet started),
1101                  * we will indulge it.
1102                  */
1103                 if (s->s3->in_read_app_data &&
1104                         (s->s3->total_renegotiations != 0) &&
1105                         ((
1106                                 (s->state & SSL_ST_CONNECT) &&
1107                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1108                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1109                                 ) || (
1110                                         (s->state & SSL_ST_ACCEPT) &&
1111                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1112                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1113                                         )
1114                                 ))
1115                         {
1116                         s->s3->in_read_app_data=0;
1117                         return(-1);
1118                         }
1119                 else
1120                         {
1121                         al=SSL_AD_UNEXPECTED_MESSAGE;
1122                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1123                         goto f_err;
1124                         }
1125                 }
1126         /* not reached */
1127
1128 f_err:
1129         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1130 err:
1131         return(-1);
1132         }
1133
1134 static int do_change_cipher_spec(SSL *s)
1135         {
1136         int i;
1137         const char *sender;
1138         int slen;
1139
1140         if (s->state & SSL_ST_ACCEPT)
1141                 i=SSL3_CHANGE_CIPHER_SERVER_READ;
1142         else
1143                 i=SSL3_CHANGE_CIPHER_CLIENT_READ;
1144
1145         if (s->s3->tmp.key_block == NULL)
1146                 {
1147                 s->session->cipher=s->s3->tmp.new_cipher;
1148                 if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
1149                 }
1150
1151         if (!s->method->ssl3_enc->change_cipher_state(s,i))
1152                 return(0);
1153
1154         /* we have to record the message digest at
1155          * this point so we can get it before we read
1156          * the finished message */
1157         if (s->state & SSL_ST_CONNECT)
1158                 {
1159                 sender=s->method->ssl3_enc->server_finished_label;
1160                 slen=s->method->ssl3_enc->server_finished_label_len;
1161                 }
1162         else
1163                 {
1164                 sender=s->method->ssl3_enc->client_finished_label;
1165                 slen=s->method->ssl3_enc->client_finished_label_len;
1166                 }
1167
1168         s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
1169                 &(s->s3->finish_dgst1),
1170                 &(s->s3->finish_dgst2),
1171                 sender,slen,s->s3->tmp.peer_finish_md);
1172
1173         return(1);
1174         }
1175
1176 void ssl3_send_alert(SSL *s, int level, int desc)
1177         {
1178         /* Map tls/ssl alert value to correct one */
1179         desc=s->method->ssl3_enc->alert_value(desc);
1180         if (desc < 0) return;
1181         /* If a fatal one, remove from cache */
1182         if ((level == 2) && (s->session != NULL))
1183                 SSL_CTX_remove_session(s->ctx,s->session);
1184
1185         s->s3->alert_dispatch=1;
1186         s->s3->send_alert[0]=level;
1187         s->s3->send_alert[1]=desc;
1188         if (s->s3->wbuf.left == 0) /* data still being written out? */
1189                 ssl3_dispatch_alert(s);
1190         /* else data is still being written out, we will get written
1191          * some time in the future */
1192         }
1193
1194 int ssl3_dispatch_alert(SSL *s)
1195         {
1196         int i,j;
1197         void (*cb)()=NULL;
1198
1199         s->s3->alert_dispatch=0;
1200         i=do_ssl3_write(s,SSL3_RT_ALERT,&s->s3->send_alert[0],2);
1201         if (i <= 0)
1202                 {
1203                 s->s3->alert_dispatch=1;
1204                 }
1205         else
1206                 {
1207                 /* Alert sent to BIO.  If it is important, flush it now.
1208                  * If the message does not get sent due to non-blocking IO,
1209                  * we will not worry too much. */
1210                 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1211                         (void)BIO_flush(s->wbio);
1212
1213                 if (s->info_callback != NULL)
1214                         cb=s->info_callback;
1215                 else if (s->ctx->info_callback != NULL)
1216                         cb=s->ctx->info_callback;
1217
1218                 if (cb != NULL)
1219                         {
1220                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1221                         cb(s,SSL_CB_WRITE_ALERT,j);
1222                         }
1223                 }
1224         return(i);
1225         }