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