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 <limits.h>
 114 #include <errno.h>
 115 #define USE_SOCKETS
 116 #include "ssl_locl.h"
 117 #include <openssl/evp.h>
 118 #include <openssl/buffer.h>
 119 #include <openssl/rand.h>
 120
 121 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 122                          unsigned int len, int create_empty_fragment);
 123 static int ssl3_get_record(SSL *s);
 124
 125 int ssl3_read_n(SSL *s, int n, int max, int extend)
 126         {
 127         /* If extend == 0, obtain new n-byte packet; if extend == 1, increase
 128          * packet by another n bytes.
 129          * The packet will be in the sub-array of s->s3->rbuf.buf specified
 130          * by s->packet and s->packet_length.
 131          * (If s->read_ahead is set, 'max' bytes may be stored in rbuf
 132          * [plus s->packet_length bytes if extend == 1].)
 133          */
 134         int i,len,left;
 135         long align=0;
 136         unsigned char *pkt;
 137         SSL3_BUFFER *rb;
 138
 139         if (n <= 0) return n;
 140
 141         rb    = &(s->s3->rbuf);
 142         if (rb->buf == NULL)
 143                 if (!ssl3_setup_read_buffer(s))
 144                         return -1;
 145
 146         left  = rb->left;
 147 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
 148         align = (long)rb->buf + SSL3_RT_HEADER_LENGTH;
 149         align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
 150 #endif
 151
 152         if (!extend)
 153                 {
 154                 /* start with empty packet ... */
 155                 if (left == 0)
 156                         rb->offset = align;
 157                 else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH)
 158                         {
 159                         /* check if next packet length is large
 160                          * enough to justify payload alignment... */
 161                         pkt = rb->buf + rb->offset;
 162                         if (pkt[0] == SSL3_RT_APPLICATION_DATA
 163                             && (pkt[3]<<8|pkt[4]) >= 128)
 164                                 {
 165                                 /* Note that even if packet is corrupted
 166                                  * and its length field is insane, we can
 167                                  * only be led to wrong decision about
 168                                  * whether memmove will occur or not.
 169                                  * Header values has no effect on memmove
 170                                  * arguments and therefore no buffer
 171                                  * overrun can be triggered. */
 172                                 memmove (rb->buf+align,pkt,left);
 173                                 rb->offset = align;
 174                                 }
 175                         }
 176                 s->packet = rb->buf + rb->offset;
 177                 s->packet_length = 0;
 178                 /* ... now we can act as if 'extend' was set */
 179                 }
 180
 181         /* For DTLS/UDP reads should not span multiple packets
 182          * because the read operation returns the whole packet
 183          * at once (as long as it fits into the buffer). */
 184         if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
 185                 {
 186                 if (left == 0 && extend)
 187                         return 0;
 188                 if (left > 0 && n > left)
 189                         n = left;
 190                 }
 191
 192         /* if there is enough in the buffer from a previous read, take some */
 193         if (left >= n)
 194                 {
 195                 s->packet_length+=n;
 196                 rb->left=left-n;
 197                 rb->offset+=n;
 198                 return(n);
 199                 }
 200
 201         /* else we need to read more data */
 202
 203         len = s->packet_length;
 204         pkt = rb->buf+align;
 205         /* Move any available bytes to front of buffer:
 206          * 'len' bytes already pointed to by 'packet',
 207          * 'left' extra ones at the end */
 208         if (s->packet != pkt) /* len > 0 */
 209                 {
 210                 memmove(pkt, s->packet, len+left);
 211                 s->packet = pkt;
 212                 rb->offset = len + align;
 213                 }
 214
 215         if (n > (int)(rb->len - rb->offset)) /* does not happen */
 216                 {
 217                 SSLerr(SSL_F_SSL3_READ_N,ERR_R_INTERNAL_ERROR);
 218                 return -1;
 219                 }
 220
 221         if (!s->read_ahead)
 222                 /* ignore max parameter */
 223                 max = n;
 224         else
 225                 {
 226                 if (max < n)
 227                         max = n;
 228                 if (max > (int)(rb->len - rb->offset))
 229                         max = rb->len - rb->offset;
 230                 }
 231
 232         while (left < n)
 233                 {
 234                 /* Now we have len+left bytes at the front of s->s3->rbuf.buf
 235                  * and need to read in more until we have len+n (up to
 236                  * len+max if possible) */
 237
 238                 clear_sys_error();
 239                 if (s->rbio != NULL)
 240                         {
 241                         s->rwstate=SSL_READING;
 242                         i=BIO_read(s->rbio,pkt+len+left, max-left);
 243                         }
 244                 else
 245                         {
 246                         SSLerr(SSL_F_SSL3_READ_N,SSL_R_READ_BIO_NOT_SET);
 247                         i = -1;
 248                         }
 249
 250                 if (i <= 0)
 251                         {
 252                         rb->left = left;
 253                         if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
 254                             SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
 255                                 if (len+left == 0)
 256                                         ssl3_release_read_buffer(s);
 257                         return(i);
 258                         }
 259                 left+=i;
 260                 /* reads should *never* span multiple packets for DTLS because
 261                  * the underlying transport protocol is message oriented as opposed
 262                  * to byte oriented as in the TLS case. */
 263                 if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
 264                         {
 265                         if (n > left)
 266                                 n = left; /* makes the while condition false */
 267                         }
 268                 }
 269
 270         /* done reading, now the book-keeping */
 271         rb->offset += n;
 272         rb->left = left - n;
 273         s->packet_length += n;
 274         s->rwstate=SSL_NOTHING;
 275         return(n);
 276         }
 277
 278 /* MAX_EMPTY_RECORDS defines the number of consecutive, empty records that will
 279  * be processed per call to ssl3_get_record. Without this limit an attacker
 280  * could send empty records at a faster rate than we can process and cause
 281  * ssl3_get_record to loop forever. */
 282 #define MAX_EMPTY_RECORDS 32
 283
 284 /* Call this to get a new input record.
 285  * It will return <= 0 if more data is needed, normally due to an error
 286  * or non-blocking IO.
 287  * When it finishes, one packet has been decoded and can be found in
 288  * ssl->s3->rrec.type    - is the type of record
 289  * ssl->s3->rrec.data,   - data
 290  * ssl->s3->rrec.length, - number of bytes
 291  */
 292 /* used only by ssl3_read_bytes */
 293 static int ssl3_get_record(SSL *s)
 294         {
 295         int ssl_major,ssl_minor,al;
 296         int enc_err,n,i,ret= -1;
 297         SSL3_RECORD *rr;
 298         SSL_SESSION *sess;
 299         unsigned char *p;
 300         unsigned char md[EVP_MAX_MD_SIZE];
 301         short version;
 302         unsigned mac_size, orig_len;
 303         size_t extra;
 304         unsigned empty_record_count = 0;
 305
 306         rr= &(s->s3->rrec);
 307         sess=s->session;
 308
 309         if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
 310                 extra=SSL3_RT_MAX_EXTRA;
 311         else
 312                 extra=0;
 313         if (extra && !s->s3->init_extra)
 314                 {
 315                 /* An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
 316                  * set after ssl3_setup_buffers() was done */
 317                 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
 318                 return -1;
 319                 }
 320
 321 again:
 322         /* check if we have the header */
 323         if (    (s->rstate != SSL_ST_READ_BODY) ||
 324                 (s->packet_length < SSL3_RT_HEADER_LENGTH))
 325                 {
 326                 n=ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 327                 if (n <= 0) return(n); /* error or non-blocking */
 328                 s->rstate=SSL_ST_READ_BODY;
 329
 330                 p=s->packet;
 331
 332                 /* Pull apart the header into the SSL3_RECORD */
 333                 rr->type= *(p++);
 334                 ssl_major= *(p++);
 335                 ssl_minor= *(p++);
 336                 version=(ssl_major<<8)|ssl_minor;
 337                 n2s(p,rr->length);
 338 #if 0
 339 fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length);
 340 #endif
 341
 342                 /* Lets check version */
 343                 if (!s->first_packet)
 344                         {
 345                         if (version != s->version)
 346                                 {
 347                                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 348                                 if ((s->version & 0xFF00) == (version & 0xFF00) && !s->enc_write_ctx && !s->write_hash)
 349                                         /* Send back error using their minor version number :-) */
 350                                         s->version = (unsigned short)version;
 351                                 al=SSL_AD_PROTOCOL_VERSION;
 352                                 goto f_err;
 353                                 }
 354                         }
 355
 356                 if ((version>>8) != SSL3_VERSION_MAJOR)
 357                         {
 358                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 359                         goto err;
 360                         }
 361
 362                 if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH)
 363                         {
 364                         al=SSL_AD_RECORD_OVERFLOW;
 365                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 366                         goto f_err;
 367                         }
 368
 369                 /* now s->rstate == SSL_ST_READ_BODY */
 370                 }
 371
 372         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 373
 374         if (rr->length > s->packet_length-SSL3_RT_HEADER_LENGTH)
 375                 {
 376                 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
 377                 i=rr->length;
 378                 n=ssl3_read_n(s,i,i,1);
 379                 if (n <= 0) return(n); /* error or non-blocking io */
 380                 /* now n == rr->length,
 381                  * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */
 382                 }
 383
 384         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 385
 386         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 387          * and we have that many bytes in s->packet
 388          */
 389         rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);
 390
 391         /* ok, we can now read from 's->packet' data into 'rr'
 392          * rr->input points at rr->length bytes, which
 393          * need to be copied into rr->data by either
 394          * the decryption or by the decompression
 395          * When the data is 'copied' into the rr->data buffer,
 396          * rr->input will be pointed at the new buffer */
 397
 398         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 399          * rr->length bytes of encrypted compressed stuff. */
 400
 401         /* check is not needed I believe */
 402         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
 403                 {
 404                 al=SSL_AD_RECORD_OVERFLOW;
 405                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 406                 goto f_err;
 407                 }
 408
 409         /* decrypt in place in 'rr->input' */
 410         rr->data=rr->input;
 411
 412         enc_err = s->method->ssl3_enc->enc(s,0);
 413         /* enc_err is:
 414          *    0: (in non-constant time) if the record is publically invalid.
 415          *    1: if the padding is valid
 416          *    -1: if the padding is invalid */
 417         if (enc_err == 0)
 418                 {
 419                 al=SSL_AD_DECRYPTION_FAILED;
 420                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
 421                 goto f_err;
 422                 }
 423
 424 #ifdef TLS_DEBUG
 425 printf("dec %d\n",rr->length);
 426 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 427 printf("\n");
 428 #endif
 429
 430         /* r->length is now the compressed data plus mac */
 431         if ((sess != NULL) &&
 432             (s->enc_read_ctx != NULL) &&
 433             (EVP_MD_CTX_md(s->read_hash) != NULL))
 434                 {
 435                 /* s->read_hash != NULL => mac_size != -1 */
 436                 unsigned char *mac = NULL;
 437                 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
 438                 mac_size=EVP_MD_CTX_size(s->read_hash);
 439                 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
 440
 441                 /* kludge: *_cbc_remove_padding passes padding length in rr->type */
 442                 orig_len = rr->length+((unsigned int)rr->type>>8);
 443
 444                 /* orig_len is the length of the record before any padding was
 445                  * removed. This is public information, as is the MAC in use,
 446                  * therefore we can safely process the record in a different
 447                  * amount of time if it's too short to possibly contain a MAC.
 448                  */
 449                 if (orig_len < mac_size ||
 450                     /* CBC records must have a padding length byte too. */
 451                     (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
 452                      orig_len < mac_size+1))
 453                         {
 454                         al=SSL_AD_DECODE_ERROR;
 455                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
 456                         goto f_err;
 457                         }
 458
 459                 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
 460                         {
 461                         /* We update the length so that the TLS header bytes
 462                          * can be constructed correctly but we need to extract
 463                          * the MAC in constant time from within the record,
 464                          * without leaking the contents of the padding bytes.
 465                          * */
 466                         mac = mac_tmp;
 467                         ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
 468                         rr->length -= mac_size;
 469                         }
 470                 else
 471                         {
 472                         /* In this case there's no padding, so |orig_len|
 473                          * equals |rec->length| and we checked that there's
 474                          * enough bytes for |mac_size| above. */
 475                         rr->length -= mac_size;
 476                         mac = &rr->data[rr->length];
 477                         }
 478
 479                 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
 480                 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
 481                         enc_err = -1;
 482                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
 483                         enc_err = -1;
 484                 }
 485
 486         if (enc_err < 0)
 487                 {
 488                 /* A separate 'decryption_failed' alert was introduced with TLS 1.0,
 489                  * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 490                  * failure is directly visible from the ciphertext anyway,
 491                  * we should not reveal which kind of error occured -- this
 492                  * might become visible to an attacker (e.g. via a logfile) */
 493                 al=SSL_AD_BAD_RECORD_MAC;
 494                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 495                 goto f_err;
 496                 }
 497
 498         /* r->length is now just compressed */
 499         if (s->expand != NULL)
 500                 {
 501                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
 502                         {
 503                         al=SSL_AD_RECORD_OVERFLOW;
 504                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 505                         goto f_err;
 506                         }
 507                 if (!ssl3_do_uncompress(s))
 508                         {
 509                         al=SSL_AD_DECOMPRESSION_FAILURE;
 510                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
 511                         goto f_err;
 512                         }
 513                 }
 514
 515         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH+extra)
 516                 {
 517                 al=SSL_AD_RECORD_OVERFLOW;
 518                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 519                 goto f_err;
 520                 }
 521
 522         rr->off=0;
 523         /* So at this point the following is true
 524          * ssl->s3->rrec.type   is the type of record
 525          * ssl->s3->rrec.length == number of bytes in record
 526          * ssl->s3->rrec.off    == offset to first valid byte
 527          * ssl->s3->rrec.data   == where to take bytes from, increment
 528          *                         after use :-).
 529          */
 530
 531         /* we have pulled in a full packet so zero things */
 532         s->packet_length=0;
 533
 534         /* just read a 0 length packet */
 535         if (rr->length == 0)
 536                 {
 537                 empty_record_count++;
 538                 if (empty_record_count > MAX_EMPTY_RECORDS)
 539                         {
 540                         al=SSL_AD_UNEXPECTED_MESSAGE;
 541                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_RECORD_TOO_SMALL);
 542                         goto f_err;
 543                         }
 544                 goto again;
 545                 }
 546
 547 #if 0
 548 fprintf(stderr, "Ultimate Record type=%d, Length=%d\n", rr->type, rr->length);
 549 #endif
 550
 551         return(1);
 552
 553 f_err:
 554         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 555 err:
 556         return(ret);
 557         }
 558
 559 int ssl3_do_uncompress(SSL *ssl)
 560         {
 561 #ifndef OPENSSL_NO_COMP
 562         int i;
 563         SSL3_RECORD *rr;
 564
 565         rr= &(ssl->s3->rrec);
 566         i=COMP_expand_block(ssl->expand,rr->comp,
 567                 SSL3_RT_MAX_PLAIN_LENGTH,rr->data,(int)rr->length);
 568         if (i < 0)
 569                 return(0);
 570         else
 571                 rr->length=i;
 572         rr->data=rr->comp;
 573 #endif
 574         return(1);
 575         }
 576
 577 int ssl3_do_compress(SSL *ssl)
 578         {
 579 #ifndef OPENSSL_NO_COMP
 580         int i;
 581         SSL3_RECORD *wr;
 582
 583         wr= &(ssl->s3->wrec);
 584         i=COMP_compress_block(ssl->compress,wr->data,
 585                 SSL3_RT_MAX_COMPRESSED_LENGTH,
 586                 wr->input,(int)wr->length);
 587         if (i < 0)
 588                 return(0);
 589         else
 590                 wr->length=i;
 591
 592         wr->input=wr->data;
 593 #endif
 594         return(1);
 595         }
 596
 597 /* Call this to write data in records of type 'type'
 598  * It will return <= 0 if not all data has been sent or non-blocking IO.
 599  */
 600 int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
 601         {
 602         const unsigned char *buf=buf_;
 603         unsigned int n,nw;
 604         int i,tot;
 605
 606         s->rwstate=SSL_NOTHING;
 607         OPENSSL_assert(s->s3->wnum <= INT_MAX);
 608         tot=s->s3->wnum;
 609         s->s3->wnum=0;
 610
 611         if (SSL_in_init(s) && !s->in_handshake)
 612                 {
 613                 i=s->handshake_func(s);
 614                 if (i < 0) return(i);
 615                 if (i == 0)
 616                         {
 617                         SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 618                         return -1;
 619                         }
 620                 }
 621
 622         /* ensure that if we end up with a smaller value of data to write
 623          * out than the the original len from a write which didn't complete
 624          * for non-blocking I/O and also somehow ended up avoiding
 625          * the check for this in ssl3_write_pending/SSL_R_BAD_WRITE_RETRY as
 626          * it must never be possible to end up with (len-tot) as a large
 627          * number that will then promptly send beyond the end of the users
 628          * buffer ... so we trap and report the error in a way the user
 629          * will notice
 630          */
 631         if (len < tot)
 632                 {
 633                 SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_BAD_LENGTH);
 634                 return(-1);
 635                 }
 636
 637
 638         n=(len-tot);
 639         for (;;)
 640                 {
 641                 if (n > s->max_send_fragment)
 642                         nw=s->max_send_fragment;
 643                 else
 644                         nw=n;
 645
 646                 i=do_ssl3_write(s, type, &(buf[tot]), nw, 0);
 647                 if (i <= 0)
 648                         {
 649                         s->s3->wnum=tot;
 650                         return i;
 651                         }
 652
 653                 if ((i == (int)n) ||
 654                         (type == SSL3_RT_APPLICATION_DATA &&
 655                          (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
 656                         {
 657                         /* next chunk of data should get another prepended empty fragment
 658                          * in ciphersuites with known-IV weakness: */
 659                         s->s3->empty_fragment_done = 0;
 660
 661                         return tot+i;
 662                         }
 663
 664                 n-=i;
 665                 tot+=i;
 666                 }
 667         }
 668
 669 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 670                          unsigned int len, int create_empty_fragment)
 671         {
 672         unsigned char *p,*plen;
 673         int i,mac_size,clear=0;
 674         int prefix_len=0;
 675         int eivlen;
 676         long align=0;
 677         SSL3_RECORD *wr;
 678         SSL3_BUFFER *wb=&(s->s3->wbuf);
 679         SSL_SESSION *sess;
 680
 681
 682         /* first check if there is a SSL3_BUFFER still being written
 683          * out.  This will happen with non blocking IO */
 684         if (wb->left != 0)
 685                 return(ssl3_write_pending(s,type,buf,len));
 686
 687         /* If we have an alert to send, lets send it */
 688         if (s->s3->alert_dispatch)
 689                 {
 690                 i=s->method->ssl_dispatch_alert(s);
 691                 if (i <= 0)
 692                         return(i);
 693                 /* if it went, fall through and send more stuff */
 694                 }
 695
 696         if (wb->buf == NULL)
 697                 if (!ssl3_setup_write_buffer(s))
 698                         return -1;
 699
 700         if (len == 0 && !create_empty_fragment)
 701                 return 0;
 702
 703         wr= &(s->s3->wrec);
 704         sess=s->session;
 705
 706         if (    (sess == NULL) ||
 707                 (s->enc_write_ctx == NULL) ||
 708                 (EVP_MD_CTX_md(s->write_hash) == NULL))
 709                 {
 710 #if 1
 711                 clear=s->enc_write_ctx?0:1;     /* must be AEAD cipher */
 712 #else
 713                 clear=1;
 714 #endif
 715                 mac_size=0;
 716                 }
 717         else
 718                 {
 719                 mac_size=EVP_MD_CTX_size(s->write_hash);
 720                 if (mac_size < 0)
 721                         goto err;
 722                 }
 723
 724         /* 'create_empty_fragment' is true only when this function calls itself */
 725         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done)
 726                 {
 727                 /* countermeasure against known-IV weakness in CBC ciphersuites
 728                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
 729
 730                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
 731                         {
 732                         /* recursive function call with 'create_empty_fragment' set;
 733                          * this prepares and buffers the data for an empty fragment
 734                          * (these 'prefix_len' bytes are sent out later
 735                          * together with the actual payload) */
 736                         prefix_len = do_ssl3_write(s, type, buf, 0, 1);
 737                         if (prefix_len <= 0)
 738                                 goto err;
 739
 740                         if (prefix_len >
 741                 (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD))
 742                                 {
 743                                 /* insufficient space */
 744                                 SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
 745                                 goto err;
 746                                 }
 747                         }
 748
 749                 s->s3->empty_fragment_done = 1;
 750                 }
 751
 752         if (create_empty_fragment)
 753                 {
 754 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
 755                 /* extra fragment would be couple of cipher blocks,
 756                  * which would be multiple of SSL3_ALIGN_PAYLOAD, so
 757                  * if we want to align the real payload, then we can
 758                  * just pretent we simply have two headers. */
 759                 align = (long)wb->buf + 2*SSL3_RT_HEADER_LENGTH;
 760                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
 761 #endif
 762                 p = wb->buf + align;
 763                 wb->offset  = align;
 764                 }
 765         else if (prefix_len)
 766                 {
 767                 p = wb->buf + wb->offset + prefix_len;
 768                 }
 769         else
 770                 {
 771 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
 772                 align = (long)wb->buf + SSL3_RT_HEADER_LENGTH;
 773                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
 774 #endif
 775                 p = wb->buf + align;
 776                 wb->offset  = align;
 777                 }
 778
 779         /* write the header */
 780
 781         *(p++)=type&0xff;
 782         wr->type=type;
 783
 784         *(p++)=(s->version>>8);
 785         /* Some servers hang if iniatial client hello is larger than 256
 786          * bytes and record version number > TLS 1.0
 787          */
 788         if (s->state == SSL3_ST_CW_CLNT_HELLO_B
 789                                 && !s->renegotiate
 790                                 && TLS1_get_version(s) > TLS1_VERSION)
 791                 *(p++) = 0x1;
 792         else
 793                 *(p++)=s->version&0xff;
 794
 795         /* field where we are to write out packet length */
 796         plen=p;
 797         p+=2;
 798         /* Explicit IV length, block ciphers and TLS version 1.1 or later */
 799         if (s->enc_write_ctx && s->version >= TLS1_1_VERSION)
 800                 {
 801                 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
 802                 if (mode == EVP_CIPH_CBC_MODE)
 803                         {
 804                         eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
 805                         if (eivlen <= 1)
 806                                 eivlen = 0;
 807                         }
 808                 /* Need explicit part of IV for GCM mode */
 809                 else if (mode == EVP_CIPH_GCM_MODE)
 810                         eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
 811                 else
 812                         eivlen = 0;
 813                 }
 814         else
 815                 eivlen = 0;
 816
 817         /* lets setup the record stuff. */
 818         wr->data=p + eivlen;
 819         wr->length=(int)len;
 820         wr->input=(unsigned char *)buf;
 821
 822         /* we now 'read' from wr->input, wr->length bytes into
 823          * wr->data */
 824
 825         /* first we compress */
 826         if (s->compress != NULL)
 827                 {
 828                 if (!ssl3_do_compress(s))
 829                         {
 830                         SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
 831                         goto err;
 832                         }
 833                 }
 834         else
 835                 {
 836                 memcpy(wr->data,wr->input,wr->length);
 837                 wr->input=wr->data;
 838                 }
 839
 840         /* we should still have the output to wr->data and the input
 841          * from wr->input.  Length should be wr->length.
 842          * wr->data still points in the wb->buf */
 843
 844         if (mac_size != 0)
 845                 {
 846                 if (s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0)
 847                         goto err;
 848                 wr->length+=mac_size;
 849                 }
 850
 851         wr->input=p;
 852         wr->data=p;
 853
 854         if (eivlen)
 855                 {
 856         /*      if (RAND_pseudo_bytes(p, eivlen) <= 0)
 857                         goto err; */
 858                 wr->length += eivlen;
 859                 }
 860
 861         if(s->method->ssl3_enc->enc(s,1)<1) goto err;
 862
 863         /* record length after mac and block padding */
 864         s2n(wr->length,plen);
 865
 866         /* we should now have
 867          * wr->data pointing to the encrypted data, which is
 868          * wr->length long */
 869         wr->type=type; /* not needed but helps for debugging */
 870         wr->length+=SSL3_RT_HEADER_LENGTH;
 871
 872         if (create_empty_fragment)
 873                 {
 874                 /* we are in a recursive call;
 875                  * just return the length, don't write out anything here
 876                  */
 877                 return wr->length;
 878                 }
 879
 880         /* now let's set up wb */
 881         wb->left = prefix_len + wr->length;
 882
 883         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
 884         s->s3->wpend_tot=len;
 885         s->s3->wpend_buf=buf;
 886         s->s3->wpend_type=type;
 887         s->s3->wpend_ret=len;
 888
 889         /* we now just need to write the buffer */
 890         return ssl3_write_pending(s,type,buf,len);
 891 err:
 892         return -1;
 893         }
 894
 895 /* if s->s3->wbuf.left != 0, we need to call this */
 896 int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
 897         unsigned int len)
 898         {
 899         int i;
 900         SSL3_BUFFER *wb=&(s->s3->wbuf);
 901
 902 /* XXXX */
 903         if ((s->s3->wpend_tot > (int)len)
 904                 || ((s->s3->wpend_buf != buf) &&
 905                         !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER))
 906                 || (s->s3->wpend_type != type))
 907                 {
 908                 SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
 909                 return(-1);
 910                 }
 911
 912         for (;;)
 913                 {
 914                 clear_sys_error();
 915                 if (s->wbio != NULL)
 916                         {
 917                         s->rwstate=SSL_WRITING;
 918                         i=BIO_write(s->wbio,
 919                                 (char *)&(wb->buf[wb->offset]),
 920                                 (unsigned int)wb->left);
 921                         }
 922                 else
 923                         {
 924                         SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
 925                         i= -1;
 926                         }
 927                 if (i == wb->left)
 928                         {
 929                         wb->left=0;
 930                         wb->offset+=i;
 931                         if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
 932                             SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
 933                                 ssl3_release_write_buffer(s);
 934                         s->rwstate=SSL_NOTHING;
 935                         return(s->s3->wpend_ret);
 936                         }
 937                 else if (i <= 0) {
 938                         if (s->version == DTLS1_VERSION ||
 939                             s->version == DTLS1_BAD_VER) {
 940                                 /* For DTLS, just drop it. That's kind of the whole
 941                                    point in using a datagram service */
 942                                 wb->left = 0;
 943                         }
 944                         return(i);
 945                 }
 946                 wb->offset+=i;
 947                 wb->left-=i;
 948                 }
 949         }
 950
 951 /* Return up to 'len' payload bytes received in 'type' records.
 952  * 'type' is one of the following:
 953  *
 954  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 955  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 956  *   -  0 (during a shutdown, no data has to be returned)
 957  *
 958  * If we don't have stored data to work from, read a SSL/TLS record first
 959  * (possibly multiple records if we still don't have anything to return).
 960  *
 961  * This function must handle any surprises the peer may have for us, such as
 962  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 963  * a surprise, but handled as if it were), or renegotiation requests.
 964  * Also if record payloads contain fragments too small to process, we store
 965  * them until there is enough for the respective protocol (the record protocol
 966  * may use arbitrary fragmentation and even interleaving):
 967  *     Change cipher spec protocol
 968  *             just 1 byte needed, no need for keeping anything stored
 969  *     Alert protocol
 970  *             2 bytes needed (AlertLevel, AlertDescription)
 971  *     Handshake protocol
 972  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 973  *             to detect unexpected Client Hello and Hello Request messages
 974  *             here, anything else is handled by higher layers
 975  *     Application data protocol
 976  *             none of our business
 977  */
 978 int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 979         {
 980         int al,i,j,ret;
 981         unsigned int n;
 982         SSL3_RECORD *rr;
 983         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 984
 985         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 986                 if (!ssl3_setup_read_buffer(s))
 987                         return(-1);
 988
 989         if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE)) ||
 990             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 991                 {
 992                 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
 993                 return -1;
 994                 }
 995
 996         if ((type == SSL3_RT_HANDSHAKE) && (s->s3->handshake_fragment_len > 0))
 997                 /* (partially) satisfy request from storage */
 998                 {
 999                 unsigned char *src = s->s3->handshake_fragment;
1000                 unsigned char *dst = buf;
1001                 unsigned int k;
1002
1003                 /* peek == 0 */
1004                 n = 0;
1005                 while ((len > 0) && (s->s3->handshake_fragment_len > 0))
1006                         {
1007                         *dst++ = *src++;
1008                         len--; s->s3->handshake_fragment_len--;
1009                         n++;
1010                         }
1011                 /* move any remaining fragment bytes: */
1012                 for (k = 0; k < s->s3->handshake_fragment_len; k++)
1013                         s->s3->handshake_fragment[k] = *src++;
1014                 return n;
1015         }
1016
1017         /* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
1018
1019         if (!s->in_handshake && SSL_in_init(s))
1020                 {
1021                 /* type == SSL3_RT_APPLICATION_DATA */
1022                 i=s->handshake_func(s);
1023                 if (i < 0) return(i);
1024                 if (i == 0)
1025                         {
1026                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1027                         return(-1);
1028                         }
1029                 }
1030 start:
1031         s->rwstate=SSL_NOTHING;
1032
1033         /* s->s3->rrec.type         - is the type of record
1034          * s->s3->rrec.data,    - data
1035          * s->s3->rrec.off,     - offset into 'data' for next read
1036          * s->s3->rrec.length,  - number of bytes. */
1037         rr = &(s->s3->rrec);
1038
1039         /* get new packet if necessary */
1040         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
1041                 {
1042                 ret=ssl3_get_record(s);
1043                 if (ret <= 0) return(ret);
1044                 }
1045
1046         /* we now have a packet which can be read and processed */
1047
1048         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
1049                                        * reset by ssl3_get_finished */
1050                 && (rr->type != SSL3_RT_HANDSHAKE))
1051                 {
1052                 al=SSL_AD_UNEXPECTED_MESSAGE;
1053                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
1054                 goto f_err;
1055                 }
1056
1057         /* If the other end has shut down, throw anything we read away
1058          * (even in 'peek' mode) */
1059         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
1060                 {
1061                 rr->length=0;
1062                 s->rwstate=SSL_NOTHING;
1063                 return(0);
1064                 }
1065
1066
1067         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
1068                 {
1069                 /* make sure that we are not getting application data when we
1070                  * are doing a handshake for the first time */
1071                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
1072                         (s->enc_read_ctx == NULL))
1073                         {
1074                         al=SSL_AD_UNEXPECTED_MESSAGE;
1075                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
1076                         goto f_err;
1077                         }
1078
1079                 if (len <= 0) return(len);
1080
1081                 if ((unsigned int)len > rr->length)
1082                         n = rr->length;
1083                 else
1084                         n = (unsigned int)len;
1085
1086                 memcpy(buf,&(rr->data[rr->off]),n);
1087                 if (!peek)
1088                         {
1089                         rr->length-=n;
1090                         rr->off+=n;
1091                         if (rr->length == 0)
1092                                 {
1093                                 s->rstate=SSL_ST_READ_HEADER;
1094                                 rr->off=0;
1095                                 if (s->mode & SSL_MODE_RELEASE_BUFFERS && s->s3->rbuf.left == 0)
1096                                         ssl3_release_read_buffer(s);
1097                                 }
1098                         }
1099                 return(n);
1100                 }
1101
1102
1103         /* If we get here, then type != rr->type; if we have a handshake
1104          * message, then it was unexpected (Hello Request or Client Hello). */
1105
1106         /* In case of record types for which we have 'fragment' storage,
1107          * fill that so that we can process the data at a fixed place.
1108          */
1109                 {
1110                 unsigned int dest_maxlen = 0;
1111                 unsigned char *dest = NULL;
1112                 unsigned int *dest_len = NULL;
1113
1114                 if (rr->type == SSL3_RT_HANDSHAKE)
1115                         {
1116                         dest_maxlen = sizeof s->s3->handshake_fragment;
1117                         dest = s->s3->handshake_fragment;
1118                         dest_len = &s->s3->handshake_fragment_len;
1119                         }
1120                 else if (rr->type == SSL3_RT_ALERT)
1121                         {
1122                         dest_maxlen = sizeof s->s3->alert_fragment;
1123                         dest = s->s3->alert_fragment;
1124                         dest_len = &s->s3->alert_fragment_len;
1125                         }
1126 #ifndef OPENSSL_NO_HEARTBEATS
1127                 else if (rr->type == TLS1_RT_HEARTBEAT)
1128                         {
1129                         tls1_process_heartbeat(s);
1130
1131                         /* Exit and notify application to read again */
1132                         rr->length = 0;
1133                         s->rwstate=SSL_READING;
1134                         BIO_clear_retry_flags(SSL_get_rbio(s));
1135                         BIO_set_retry_read(SSL_get_rbio(s));
1136                         return(-1);
1137                         }
1138 #endif
1139
1140                 if (dest_maxlen > 0)
1141                         {
1142                         n = dest_maxlen - *dest_len; /* available space in 'dest' */
1143                         if (rr->length < n)
1144                                 n = rr->length; /* available bytes */
1145
1146                         /* now move 'n' bytes: */
1147                         while (n-- > 0)
1148                                 {
1149                                 dest[(*dest_len)++] = rr->data[rr->off++];
1150                                 rr->length--;
1151                                 }
1152
1153                         if (*dest_len < dest_maxlen)
1154                                 goto start; /* fragment was too small */
1155                         }
1156                 }
1157
1158         /* s->s3->handshake_fragment_len == 4  iff  rr->type == SSL3_RT_HANDSHAKE;
1159          * s->s3->alert_fragment_len == 2      iff  rr->type == SSL3_RT_ALERT.
1160          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1161
1162         /* If we are a client, check for an incoming 'Hello Request': */
1163         if ((!s->server) &&
1164                 (s->s3->handshake_fragment_len >= 4) &&
1165                 (s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1166                 (s->session != NULL) && (s->session->cipher != NULL))
1167                 {
1168                 s->s3->handshake_fragment_len = 0;
1169
1170                 if ((s->s3->handshake_fragment[1] != 0) ||
1171                         (s->s3->handshake_fragment[2] != 0) ||
1172                         (s->s3->handshake_fragment[3] != 0))
1173                         {
1174                         al=SSL_AD_DECODE_ERROR;
1175                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1176                         goto f_err;
1177                         }
1178
1179                 if (s->msg_callback)
1180                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->s3->handshake_fragment, 4, s, s->msg_callback_arg);
1181
1182                 if (SSL_is_init_finished(s) &&
1183                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1184                         !s->s3->renegotiate)
1185                         {
1186                         ssl3_renegotiate(s);
1187                         if (ssl3_renegotiate_check(s))
1188                                 {
1189                                 i=s->handshake_func(s);
1190                                 if (i < 0) return(i);
1191                                 if (i == 0)
1192                                         {
1193                                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1194                                         return(-1);
1195                                         }
1196
1197                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1198                                         {
1199                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1200                                                 {
1201                                                 BIO *bio;
1202                                                 /* In the case where we try to read application data,
1203                                                  * but we trigger an SSL handshake, we return -1 with
1204                                                  * the retry option set.  Otherwise renegotiation may
1205                                                  * cause nasty problems in the blocking world */
1206                                                 s->rwstate=SSL_READING;
1207                                                 bio=SSL_get_rbio(s);
1208                                                 BIO_clear_retry_flags(bio);
1209                                                 BIO_set_retry_read(bio);
1210                                                 return(-1);
1211                                                 }
1212                                         }
1213                                 }
1214                         }
1215                 /* we either finished a handshake or ignored the request,
1216                  * now try again to obtain the (application) data we were asked for */
1217                 goto start;
1218                 }
1219         /* If we are a server and get a client hello when renegotiation isn't
1220          * allowed send back a no renegotiation alert and carry on.
1221          * WARNING: experimental code, needs reviewing (steve)
1222          */
1223         if (s->server &&
1224                 SSL_is_init_finished(s) &&
1225                 !s->s3->send_connection_binding &&
1226                 (s->version > SSL3_VERSION) &&
1227                 (s->s3->handshake_fragment_len >= 4) &&
1228                 (s->s3->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) &&
1229                 (s->session != NULL) && (s->session->cipher != NULL) &&
1230                 !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
1231
1232                 {
1233                 /*s->s3->handshake_fragment_len = 0;*/
1234                 rr->length = 0;
1235                 ssl3_send_alert(s,SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
1236                 goto start;
1237                 }
1238         if (s->s3->alert_fragment_len >= 2)
1239                 {
1240                 int alert_level = s->s3->alert_fragment[0];
1241                 int alert_descr = s->s3->alert_fragment[1];
1242
1243                 s->s3->alert_fragment_len = 0;
1244
1245                 if (s->msg_callback)
1246                         s->msg_callback(0, s->version, SSL3_RT_ALERT, s->s3->alert_fragment, 2, s, s->msg_callback_arg);
1247
1248                 if (s->info_callback != NULL)
1249                         cb=s->info_callback;
1250                 else if (s->ctx->info_callback != NULL)
1251                         cb=s->ctx->info_callback;
1252
1253                 if (cb != NULL)
1254                         {
1255                         j = (alert_level << 8) | alert_descr;
1256                         cb(s, SSL_CB_READ_ALERT, j);
1257                         }
1258
1259                 if (alert_level == 1) /* warning */
1260                         {
1261                         s->s3->warn_alert = alert_descr;
1262                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1263                                 {
1264                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1265                                 return(0);
1266                                 }
1267                         /* This is a warning but we receive it if we requested
1268                          * renegotiation and the peer denied it. Terminate with
1269                          * a fatal alert because if application tried to
1270                          * renegotiatie it presumably had a good reason and
1271                          * expects it to succeed.
1272                          *
1273                          * In future we might have a renegotiation where we
1274                          * don't care if the peer refused it where we carry on.
1275                          */
1276                         else if (alert_descr == SSL_AD_NO_RENEGOTIATION)
1277                                 {
1278                                 al = SSL_AD_HANDSHAKE_FAILURE;
1279                                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_NO_RENEGOTIATION);
1280                                 goto f_err;
1281                                 }
1282 #ifdef SSL_AD_MISSING_SRP_USERNAME
1283                         else if (alert_descr == SSL_AD_MISSING_SRP_USERNAME)
1284                                 return(0);
1285 #endif
1286                         }
1287                 else if (alert_level == 2) /* fatal */
1288                         {
1289                         char tmp[16];
1290
1291                         s->rwstate=SSL_NOTHING;
1292                         s->s3->fatal_alert = alert_descr;
1293                         SSLerr(SSL_F_SSL3_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1294                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1295                         ERR_add_error_data(2,"SSL alert number ",tmp);
1296                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1297                         SSL_CTX_remove_session(s->ctx,s->session);
1298                         return(0);
1299                         }
1300                 else
1301                         {
1302                         al=SSL_AD_ILLEGAL_PARAMETER;
1303                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1304                         goto f_err;
1305                         }
1306
1307                 goto start;
1308                 }
1309
1310         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1311                 {
1312                 s->rwstate=SSL_NOTHING;
1313                 rr->length=0;
1314                 return(0);
1315                 }
1316
1317         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1318                 {
1319                 /* 'Change Cipher Spec' is just a single byte, so we know
1320                  * exactly what the record payload has to look like */
1321                 if (    (rr->length != 1) || (rr->off != 0) ||
1322                         (rr->data[0] != SSL3_MT_CCS))
1323                         {
1324                         al=SSL_AD_ILLEGAL_PARAMETER;
1325                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1326                         goto f_err;
1327                         }
1328
1329                 /* Check we have a cipher to change to */
1330                 if (s->s3->tmp.new_cipher == NULL)
1331                         {
1332                         al=SSL_AD_UNEXPECTED_MESSAGE;
1333                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
1334                         goto f_err;
1335                         }
1336
1337                 if (!(s->s3->flags & SSL3_FLAGS_CCS_OK))
1338                         {
1339                         al=SSL_AD_UNEXPECTED_MESSAGE;
1340                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
1341                         goto f_err;
1342                         }
1343
1344                 s->s3->flags &= ~SSL3_FLAGS_CCS_OK;
1345
1346                 rr->length=0;
1347
1348                 if (s->msg_callback)
1349                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, s->msg_callback_arg);
1350
1351                 s->s3->change_cipher_spec=1;
1352                 if (!ssl3_do_change_cipher_spec(s))
1353                         goto err;
1354                 else
1355                         goto start;
1356                 }
1357
1358         /* Unexpected handshake message (Client Hello, or protocol violation) */
1359         if ((s->s3->handshake_fragment_len >= 4) &&     !s->in_handshake)
1360                 {
1361                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1362                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1363                         {
1364 #if 0 /* worked only because C operator preferences are not as expected (and
1365        * because this is not really needed for clients except for detecting
1366        * protocol violations): */
1367                         s->state=SSL_ST_BEFORE|(s->server)
1368                                 ?SSL_ST_ACCEPT
1369                                 :SSL_ST_CONNECT;
1370 #else
1371                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1372 #endif
1373                         s->renegotiate=1;
1374                         s->new_session=1;
1375                         }
1376                 i=s->handshake_func(s);
1377                 if (i < 0) return(i);
1378                 if (i == 0)
1379                         {
1380                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1381                         return(-1);
1382                         }
1383
1384                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1385                         {
1386                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1387                                 {
1388                                 BIO *bio;
1389                                 /* In the case where we try to read application data,
1390                                  * but we trigger an SSL handshake, we return -1 with
1391                                  * the retry option set.  Otherwise renegotiation may
1392                                  * cause nasty problems in the blocking world */
1393                                 s->rwstate=SSL_READING;
1394                                 bio=SSL_get_rbio(s);
1395                                 BIO_clear_retry_flags(bio);
1396                                 BIO_set_retry_read(bio);
1397                                 return(-1);
1398                                 }
1399                         }
1400                 goto start;
1401                 }
1402
1403         switch (rr->type)
1404                 {
1405         default:
1406 #ifndef OPENSSL_NO_TLS
1407                 /* TLS up to v1.1 just ignores unknown message types:
1408                  * TLS v1.2 give an unexpected message alert.
1409                  */
1410                 if (s->version >= TLS1_VERSION && s->version <= TLS1_1_VERSION)
1411                         {
1412                         rr->length = 0;
1413                         goto start;
1414                         }
1415 #endif
1416                 al=SSL_AD_UNEXPECTED_MESSAGE;
1417                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1418                 goto f_err;
1419         case SSL3_RT_CHANGE_CIPHER_SPEC:
1420         case SSL3_RT_ALERT:
1421         case SSL3_RT_HANDSHAKE:
1422                 /* we already handled all of these, with the possible exception
1423                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1424                  * should not happen when type != rr->type */
1425                 al=SSL_AD_UNEXPECTED_MESSAGE;
1426                 SSLerr(SSL_F_SSL3_READ_BYTES,ERR_R_INTERNAL_ERROR);
1427                 goto f_err;
1428         case SSL3_RT_APPLICATION_DATA:
1429                 /* At this point, we were expecting handshake data,
1430                  * but have application data.  If the library was
1431                  * running inside ssl3_read() (i.e. in_read_app_data
1432                  * is set) and it makes sense to read application data
1433                  * at this point (session renegotiation not yet started),
1434                  * we will indulge it.
1435                  */
1436                 if (s->s3->in_read_app_data &&
1437                         (s->s3->total_renegotiations != 0) &&
1438                         ((
1439                                 (s->state & SSL_ST_CONNECT) &&
1440                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1441                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1442                                 ) || (
1443                                         (s->state & SSL_ST_ACCEPT) &&
1444                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1445                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1446                                         )
1447                                 ))
1448                         {
1449                         s->s3->in_read_app_data=2;
1450                         return(-1);
1451                         }
1452                 else
1453                         {
1454                         al=SSL_AD_UNEXPECTED_MESSAGE;
1455                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1456                         goto f_err;
1457                         }
1458                 }
1459         /* not reached */
1460
1461 f_err:
1462         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1463 err:
1464         return(-1);
1465         }
1466
1467 int ssl3_do_change_cipher_spec(SSL *s)
1468         {
1469         int i;
1470         const char *sender;
1471         int slen;
1472
1473         if (s->state & SSL_ST_ACCEPT)
1474                 i=SSL3_CHANGE_CIPHER_SERVER_READ;
1475         else
1476                 i=SSL3_CHANGE_CIPHER_CLIENT_READ;
1477
1478         if (s->s3->tmp.key_block == NULL)
1479                 {
1480                 if (s->session == NULL || s->session->master_key_length == 0)
1481                         {
1482                         /* might happen if dtls1_read_bytes() calls this */
1483                         SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_CCS_RECEIVED_EARLY);
1484                         return (0);
1485                         }
1486
1487                 s->session->cipher=s->s3->tmp.new_cipher;
1488                 if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
1489                 }
1490
1491         if (!s->method->ssl3_enc->change_cipher_state(s,i))
1492                 return(0);
1493
1494         /* we have to record the message digest at
1495          * this point so we can get it before we read
1496          * the finished message */
1497         if (s->state & SSL_ST_CONNECT)
1498                 {
1499                 sender=s->method->ssl3_enc->server_finished_label;
1500                 slen=s->method->ssl3_enc->server_finished_label_len;
1501                 }
1502         else
1503                 {
1504                 sender=s->method->ssl3_enc->client_finished_label;
1505                 slen=s->method->ssl3_enc->client_finished_label_len;
1506                 }
1507
1508         i = s->method->ssl3_enc->final_finish_mac(s,
1509                 sender,slen,s->s3->tmp.peer_finish_md);
1510         if (i == 0)
1511                 {
1512                 SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
1513                 return 0;
1514                 }
1515         s->s3->tmp.peer_finish_md_len = i;
1516
1517         return(1);
1518         }
1519
1520 int ssl3_send_alert(SSL *s, int level, int desc)
1521         {
1522         /* Map tls/ssl alert value to correct one */
1523         desc=s->method->ssl3_enc->alert_value(desc);
1524         if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION)
1525                 desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have protocol_version alerts */
1526         if (desc < 0) return -1;
1527         /* If a fatal one, remove from cache */
1528         if ((level == 2) && (s->session != NULL))
1529                 SSL_CTX_remove_session(s->ctx,s->session);
1530
1531         s->s3->alert_dispatch=1;
1532         s->s3->send_alert[0]=level;
1533         s->s3->send_alert[1]=desc;
1534         if (s->s3->wbuf.left == 0) /* data still being written out? */
1535                 return s->method->ssl_dispatch_alert(s);
1536         /* else data is still being written out, we will get written
1537          * some time in the future */
1538         return -1;
1539         }
1540
1541 int ssl3_dispatch_alert(SSL *s)
1542         {
1543         int i,j;
1544         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1545
1546         s->s3->alert_dispatch=0;
1547         i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0);
1548         if (i <= 0)
1549                 {
1550                 s->s3->alert_dispatch=1;
1551                 }
1552         else
1553                 {
1554                 /* Alert sent to BIO.  If it is important, flush it now.
1555                  * If the message does not get sent due to non-blocking IO,
1556                  * we will not worry too much. */
1557                 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1558                         (void)BIO_flush(s->wbio);
1559
1560                 if (s->msg_callback)
1561                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s, s->msg_callback_arg);
1562
1563                 if (s->info_callback != NULL)
1564                         cb=s->info_callback;
1565                 else if (s->ctx->info_callback != NULL)
1566                         cb=s->ctx->info_callback;
1567
1568                 if (cb != NULL)
1569                         {
1570                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1571                         cb(s,SSL_CB_WRITE_ALERT,j);
1572                         }
1573                 }
1574         return(i);
1575         }