ssl/s3_pkt.c

   1 /* ssl/s3_pkt.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58 /* ====================================================================
  59  * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
  60  *
  61  * Redistribution and use in source and binary forms, with or without
  62  * modification, are permitted provided that the following conditions
  63  * are met:
  64  *
  65  * 1. Redistributions of source code must retain the above copyright
  66  *    notice, this list of conditions and the following disclaimer.
  67  *
  68  * 2. Redistributions in binary form must reproduce the above copyright
  69  *    notice, this list of conditions and the following disclaimer in
  70  *    the documentation and/or other materials provided with the
  71  *    distribution.
  72  *
  73  * 3. All advertising materials mentioning features or use of this
  74  *    software must display the following acknowledgment:
  75  *    "This product includes software developed by the OpenSSL Project
  76  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  77  *
  78  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  79  *    endorse or promote products derived from this software without
  80  *    prior written permission. For written permission, please contact
  81  *    openssl-core@openssl.org.
  82  *
  83  * 5. Products derived from this software may not be called "OpenSSL"
  84  *    nor may "OpenSSL" appear in their names without prior written
  85  *    permission of the OpenSSL Project.
  86  *
  87  * 6. Redistributions of any form whatsoever must retain the following
  88  *    acknowledgment:
  89  *    "This product includes software developed by the OpenSSL Project
  90  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  91  *
  92  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  93  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  94  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  95  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  96  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  97  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  98  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  99  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 100  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 101  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 102  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 103  * OF THE POSSIBILITY OF SUCH DAMAGE.
 104  * ====================================================================
 105  *
 106  * This product includes cryptographic software written by Eric Young
 107  * (eay@cryptsoft.com).  This product includes software written by Tim
 108  * Hudson (tjh@cryptsoft.com).
 109  *
 110  */
 111
 112 #include <stdio.h>
 113 #include <errno.h>
 114 #define USE_SOCKETS
 115 #include "ssl_locl.h"
 116 #include <openssl/evp.h>
 117 #include <openssl/buffer.h>
 118 #include <openssl/rand.h>
 119
 120 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 121                          unsigned int len, int create_empty_fragment);
 122 static int ssl3_get_record(SSL *s);
 123
 124 int ssl3_read_n(SSL *s, int n, int max, int extend)
 125         {
 126         /* If extend == 0, obtain new n-byte packet; if extend == 1, increase
 127          * packet by another n bytes.
 128          * The packet will be in the sub-array of s->s3->rbuf.buf specified
 129          * by s->packet and s->packet_length.
 130          * (If s->read_ahead is set, 'max' bytes may be stored in rbuf
 131          * [plus s->packet_length bytes if extend == 1].)
 132          */
 133         int i,len,left;
 134         long align=0;
 135         unsigned char *pkt;
 136         SSL3_BUFFER *rb;
 137
 138         if (n <= 0) return n;
 139
 140         rb    = &(s->s3->rbuf);
 141         if (rb->buf == NULL)
 142                 if (!ssl3_setup_read_buffer(s))
 143                         return -1;
 144
 145         left  = rb->left;
 146 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
 147         align = (long)rb->buf + SSL3_RT_HEADER_LENGTH;
 148         align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
 149 #endif
 150
 151         if (!extend)
 152                 {
 153                 /* start with empty packet ... */
 154                 if (left == 0)
 155                         rb->offset = align;
 156                 else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH)
 157                         {
 158                         /* check if next packet length is large
 159                          * enough to justify payload alignment... */
 160                         pkt = rb->buf + rb->offset;
 161                         if (pkt[0] == SSL3_RT_APPLICATION_DATA
 162                             && (pkt[3]<<8|pkt[4]) >= 128)
 163                                 {
 164                                 /* Note that even if packet is corrupted
 165                                  * and its length field is insane, we can
 166                                  * only be led to wrong decision about
 167                                  * whether memmove will occur or not.
 168                                  * Header values has no effect on memmove
 169                                  * arguments and therefore no buffer
 170                                  * overrun can be triggered. */
 171                                 memmove (rb->buf+align,pkt,left);
 172                                 rb->offset = align;
 173                                 }
 174                         }
 175                 s->packet = rb->buf + rb->offset;
 176                 s->packet_length = 0;
 177                 /* ... now we can act as if 'extend' was set */
 178                 }
 179
 180         /* For DTLS/UDP reads should not span multiple packets
 181          * because the read operation returns the whole packet
 182          * at once (as long as it fits into the buffer). */
 183         if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
 184                 {
 185                 if (left > 0 && n > left)
 186                         n = left;
 187                 }
 188
 189         /* if there is enough in the buffer from a previous read, take some */
 190         if (left >= n)
 191                 {
 192                 s->packet_length+=n;
 193                 rb->left=left-n;
 194                 rb->offset+=n;
 195                 return(n);
 196                 }
 197
 198         /* else we need to read more data */
 199
 200         len = s->packet_length;
 201         pkt = rb->buf+align;
 202         /* Move any available bytes to front of buffer:
 203          * 'len' bytes already pointed to by 'packet',
 204          * 'left' extra ones at the end */
 205         if (s->packet != pkt) /* len > 0 */
 206                 {
 207                 memmove(pkt, s->packet, len+left);
 208                 s->packet = pkt;
 209                 rb->offset = len + align;
 210                 }
 211
 212         if (n > (int)(rb->len - rb->offset)) /* does not happen */
 213                 {
 214                 SSLerr(SSL_F_SSL3_READ_N,ERR_R_INTERNAL_ERROR);
 215                 return -1;
 216                 }
 217
 218         if (!s->read_ahead)
 219                 /* ignore max parameter */
 220                 max = n;
 221         else
 222                 {
 223                 if (max < n)
 224                         max = n;
 225                 if (max > (int)(rb->len - rb->offset))
 226                         max = rb->len - rb->offset;
 227                 }
 228
 229         while (left < n)
 230                 {
 231                 /* Now we have len+left bytes at the front of s->s3->rbuf.buf
 232                  * and need to read in more until we have len+n (up to
 233                  * len+max if possible) */
 234
 235                 clear_sys_error();
 236                 if (s->rbio != NULL)
 237                         {
 238                         s->rwstate=SSL_READING;
 239                         i=BIO_read(s->rbio,pkt+len+left, max-left);
 240                         }
 241                 else
 242                         {
 243                         SSLerr(SSL_F_SSL3_READ_N,SSL_R_READ_BIO_NOT_SET);
 244                         i = -1;
 245                         }
 246
 247                 if (i <= 0)
 248                         {
 249                         rb->left = left;
 250                         if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
 251                             SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
 252                                 if (len+left == 0)
 253                                         ssl3_release_read_buffer(s);
 254                         return(i);
 255                         }
 256                 left+=i;
 257                 /* reads should *never* span multiple packets for DTLS because
 258                  * the underlying transport protocol is message oriented as opposed
 259                  * to byte oriented as in the TLS case. */
 260                 if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
 261                         {
 262                         if (n > left)
 263                                 n = left; /* makes the while condition false */
 264                         }
 265                 }
 266
 267         /* done reading, now the book-keeping */
 268         rb->offset += n;
 269         rb->left = left - n;
 270         s->packet_length += n;
 271         s->rwstate=SSL_NOTHING;
 272         return(n);
 273         }
 274
 275 /* Call this to get a new input record.
 276  * It will return <= 0 if more data is needed, normally due to an error
 277  * or non-blocking IO.
 278  * When it finishes, one packet has been decoded and can be found in
 279  * ssl->s3->rrec.type    - is the type of record
 280  * ssl->s3->rrec.data,   - data
 281  * ssl->s3->rrec.length, - number of bytes
 282  */
 283 /* used only by ssl3_read_bytes */
 284 static int ssl3_get_record(SSL *s)
 285         {
 286         int ssl_major,ssl_minor,al;
 287         int enc_err,n,i,ret= -1;
 288         SSL3_RECORD *rr;
 289         SSL_SESSION *sess;
 290         unsigned char *p;
 291         unsigned char md[EVP_MAX_MD_SIZE];
 292         short version;
 293         unsigned mac_size;
 294         int clear=0;
 295         size_t extra;
 296
 297         rr= &(s->s3->rrec);
 298         sess=s->session;
 299
 300         if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
 301                 extra=SSL3_RT_MAX_EXTRA;
 302         else
 303                 extra=0;
 304         if (extra && !s->s3->init_extra)
 305                 {
 306                 /* An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
 307                  * set after ssl3_setup_buffers() was done */
 308                 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
 309                 return -1;
 310                 }
 311
 312 again:
 313         /* check if we have the header */
 314         if (    (s->rstate != SSL_ST_READ_BODY) ||
 315                 (s->packet_length < SSL3_RT_HEADER_LENGTH))
 316                 {
 317                 n=ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 318                 if (n <= 0) return(n); /* error or non-blocking */
 319                 s->rstate=SSL_ST_READ_BODY;
 320
 321                 p=s->packet;
 322                 if (s->msg_callback)
 323                         s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s, s->msg_callback_arg);
 324
 325                 /* Pull apart the header into the SSL3_RECORD */
 326                 rr->type= *(p++);
 327                 ssl_major= *(p++);
 328                 ssl_minor= *(p++);
 329                 version=(ssl_major<<8)|ssl_minor;
 330                 n2s(p,rr->length);
 331 #if 0
 332 fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length);
 333 #endif
 334
 335                 /* Lets check version */
 336                 if (!s->first_packet)
 337                         {
 338                         if (version != s->version)
 339                                 {
 340                                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 341                                 if ((s->version & 0xFF00) == (version & 0xFF00))
 342                                         /* Send back error using their minor version number :-) */
 343                                         s->version = (unsigned short)version;
 344                                 al=SSL_AD_PROTOCOL_VERSION;
 345                                 goto f_err;
 346                                 }
 347                         }
 348
 349                 if ((version>>8) != SSL3_VERSION_MAJOR)
 350                         {
 351                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 352                         goto err;
 353                         }
 354
 355                 if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH)
 356                         {
 357                         al=SSL_AD_RECORD_OVERFLOW;
 358                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 359                         goto f_err;
 360                         }
 361
 362                 /* now s->rstate == SSL_ST_READ_BODY */
 363                 }
 364
 365         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 366
 367         if (rr->length > s->packet_length-SSL3_RT_HEADER_LENGTH)
 368                 {
 369                 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
 370                 i=rr->length;
 371                 n=ssl3_read_n(s,i,i,1);
 372                 if (n <= 0) return(n); /* error or non-blocking io */
 373                 /* now n == rr->length,
 374                  * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */
 375                 }
 376
 377         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 378
 379         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 380          * and we have that many bytes in s->packet
 381          */
 382         rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);
 383
 384         /* ok, we can now read from 's->packet' data into 'rr'
 385          * rr->input points at rr->length bytes, which
 386          * need to be copied into rr->data by either
 387          * the decryption or by the decompression
 388          * When the data is 'copied' into the rr->data buffer,
 389          * rr->input will be pointed at the new buffer */
 390
 391         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 392          * rr->length bytes of encrypted compressed stuff. */
 393
 394         /* check is not needed I believe */
 395         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
 396                 {
 397                 al=SSL_AD_RECORD_OVERFLOW;
 398                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 399                 goto f_err;
 400                 }
 401
 402         /* decrypt in place in 'rr->input' */
 403         rr->data=rr->input;
 404         rr->orig_len=rr->length;
 405
 406         enc_err = s->method->ssl3_enc->enc(s,0);
 407         /* enc_err is:
 408          *    0: (in non-constant time) if the record is publically invalid.
 409          *    1: if the padding is valid
 410          *    -1: if the padding is invalid */
 411         if (enc_err == 0)
 412                 {
 413                 /* SSLerr() and ssl3_send_alert() have been called */
 414                 goto err;
 415                 }
 416
 417 #ifdef TLS_DEBUG
 418 printf("dec %d\n",rr->length);
 419 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 420 printf("\n");
 421 #endif
 422
 423         /* r->length is now the compressed data plus mac */
 424         if (    (sess == NULL) ||
 425                 (s->enc_read_ctx == NULL) ||
 426                 (EVP_MD_CTX_md(s->read_hash) == NULL))
 427                 clear=1;
 428
 429         if (!clear)
 430                 {
 431                 /* !clear => s->read_hash != NULL => mac_size != -1 */
 432                 unsigned char *mac = NULL;
 433                 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
 434                 mac_size=EVP_MD_CTX_size(s->read_hash);
 435                 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
 436
 437                 /* orig_len is the length of the record before any padding was
 438                  * removed. This is public information, as is the MAC in use,
 439                  * therefore we can safely process the record in a different
 440                  * amount of time if it's too short to possibly contain a MAC.
 441                  */
 442                 if (rr->orig_len < mac_size ||
 443                     /* CBC records must have a padding length byte too. */
 444                     (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
 445                      rr->orig_len < mac_size+1))
 446                         {
 447                         al=SSL_AD_DECODE_ERROR;
 448                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
 449                         goto f_err;
 450                         }
 451
 452                 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
 453                         {
 454                         /* We update the length so that the TLS header bytes
 455                          * can be constructed correctly but we need to extract
 456                          * the MAC in constant time from within the record,
 457                          * without leaking the contents of the padding bytes.
 458                          * */
 459                         mac = mac_tmp;
 460                         ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
 461                         rr->length -= mac_size;
 462                         }
 463                 else
 464                         {
 465                         /* In this case there's no padding, so |rec->orig_len|
 466                          * equals |rec->length| and we checked that there's
 467                          * enough bytes for |mac_size| above. */
 468                         rr->length -= mac_size;
 469                         mac = &rr->data[rr->length];
 470                         }
 471
 472                 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
 473                 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
 474                         enc_err = -1;
 475                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
 476                         enc_err = -1;
 477                 }
 478
 479         if (enc_err < 0)
 480                 {
 481                 /* A separate 'decryption_failed' alert was introduced with TLS 1.0,
 482                  * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 483                  * failure is directly visible from the ciphertext anyway,
 484                  * we should not reveal which kind of error occured -- this
 485                  * might become visible to an attacker (e.g. via a logfile) */
 486                 al=SSL_AD_BAD_RECORD_MAC;
 487                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 488                 goto f_err;
 489                 }
 490
 491         /* r->length is now just compressed */
 492         if (s->expand != NULL)
 493                 {
 494                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
 495                         {
 496                         al=SSL_AD_RECORD_OVERFLOW;
 497                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 498                         goto f_err;
 499                         }
 500                 if (!ssl3_do_uncompress(s))
 501                         {
 502                         al=SSL_AD_DECOMPRESSION_FAILURE;
 503                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
 504                         goto f_err;
 505                         }
 506                 }
 507
 508         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH+extra)
 509                 {
 510                 al=SSL_AD_RECORD_OVERFLOW;
 511                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 512                 goto f_err;
 513                 }
 514
 515         rr->off=0;
 516         /* So at this point the following is true
 517          * ssl->s3->rrec.type   is the type of record
 518          * ssl->s3->rrec.length == number of bytes in record
 519          * ssl->s3->rrec.off    == offset to first valid byte
 520          * ssl->s3->rrec.data   == where to take bytes from, increment
 521          *                         after use :-).
 522          */
 523
 524         /* we have pulled in a full packet so zero things */
 525         s->packet_length=0;
 526
 527         /* just read a 0 length packet */
 528         if (rr->length == 0) goto again;
 529
 530 #if 0
 531 fprintf(stderr, "Ultimate Record type=%d, Length=%d\n", rr->type, rr->length);
 532 #endif
 533
 534         return(1);
 535
 536 f_err:
 537         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 538 err:
 539         return(ret);
 540         }
 541
 542 int ssl3_do_uncompress(SSL *ssl)
 543         {
 544 #ifndef OPENSSL_NO_COMP
 545         int i;
 546         SSL3_RECORD *rr;
 547
 548         rr= &(ssl->s3->rrec);
 549         i=COMP_expand_block(ssl->expand,rr->comp,
 550                 SSL3_RT_MAX_PLAIN_LENGTH,rr->data,(int)rr->length);
 551         if (i < 0)
 552                 return(0);
 553         else
 554                 rr->length=i;
 555         rr->data=rr->comp;
 556 #endif
 557         return(1);
 558         }
 559
 560 int ssl3_do_compress(SSL *ssl)
 561         {
 562 #ifndef OPENSSL_NO_COMP
 563         int i;
 564         SSL3_RECORD *wr;
 565
 566         wr= &(ssl->s3->wrec);
 567         i=COMP_compress_block(ssl->compress,wr->data,
 568                 SSL3_RT_MAX_COMPRESSED_LENGTH,
 569                 wr->input,(int)wr->length);
 570         if (i < 0)
 571                 return(0);
 572         else
 573                 wr->length=i;
 574
 575         wr->input=wr->data;
 576 #endif
 577         return(1);
 578         }
 579
 580 /* Call this to write data in records of type 'type'
 581  * It will return <= 0 if not all data has been sent or non-blocking IO.
 582  */
 583 int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
 584         {
 585         const unsigned char *buf=buf_;
 586         unsigned int tot,n,nw;
 587         int i;
 588
 589         s->rwstate=SSL_NOTHING;
 590         tot=s->s3->wnum;
 591         s->s3->wnum=0;
 592
 593         if (SSL_in_init(s) && !s->in_handshake)
 594                 {
 595                 i=s->handshake_func(s);
 596                 if (i < 0) return(i);
 597                 if (i == 0)
 598                         {
 599                         SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 600                         return -1;
 601                         }
 602                 }
 603
 604         n=(len-tot);
 605         for (;;)
 606                 {
 607                 if (n > s->max_send_fragment)
 608                         nw=s->max_send_fragment;
 609                 else
 610                         nw=n;
 611
 612                 i=do_ssl3_write(s, type, &(buf[tot]), nw, 0);
 613                 if (i <= 0)
 614                         {
 615                         s->s3->wnum=tot;
 616                         return i;
 617                         }
 618
 619                 if ((i == (int)n) ||
 620                         (type == SSL3_RT_APPLICATION_DATA &&
 621                          (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
 622                         {
 623                         /* next chunk of data should get another prepended empty fragment
 624                          * in ciphersuites with known-IV weakness: */
 625                         s->s3->empty_fragment_done = 0;
 626
 627                         return tot+i;
 628                         }
 629
 630                 n-=i;
 631                 tot+=i;
 632                 }
 633         }
 634
 635 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 636                          unsigned int len, int create_empty_fragment)
 637         {
 638         unsigned char *p,*plen;
 639         int i,mac_size,clear=0;
 640         int prefix_len=0;
 641         int eivlen;
 642         long align=0;
 643         SSL3_RECORD *wr;
 644         SSL3_BUFFER *wb=&(s->s3->wbuf);
 645         SSL_SESSION *sess;
 646
 647         if (wb->buf == NULL)
 648                 if (!ssl3_setup_write_buffer(s))
 649                         return -1;
 650
 651         /* first check if there is a SSL3_BUFFER still being written
 652          * out.  This will happen with non blocking IO */
 653         if (wb->left != 0)
 654                 return(ssl3_write_pending(s,type,buf,len));
 655
 656         /* If we have an alert to send, lets send it */
 657         if (s->s3->alert_dispatch)
 658                 {
 659                 i=s->method->ssl_dispatch_alert(s);
 660                 if (i <= 0)
 661                         return(i);
 662                 /* if it went, fall through and send more stuff */
 663                 }
 664
 665         if (len == 0 && !create_empty_fragment)
 666                 return 0;
 667
 668         wr= &(s->s3->wrec);
 669         sess=s->session;
 670
 671         if (    (sess == NULL) ||
 672                 (s->enc_write_ctx == NULL) ||
 673                 (EVP_MD_CTX_md(s->write_hash) == NULL))
 674                 {
 675 #if 1
 676                 clear=s->enc_write_ctx?0:1;     /* must be AEAD cipher */
 677 #else
 678                 clear=1;
 679 #endif
 680                 mac_size=0;
 681                 }
 682         else
 683                 {
 684                 mac_size=EVP_MD_CTX_size(s->write_hash);
 685                 if (mac_size < 0)
 686                         goto err;
 687                 }
 688
 689         /* 'create_empty_fragment' is true only when this function calls itself */
 690         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done)
 691                 {
 692                 /* countermeasure against known-IV weakness in CBC ciphersuites
 693                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
 694
 695                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
 696                         {
 697                         /* recursive function call with 'create_empty_fragment' set;
 698                          * this prepares and buffers the data for an empty fragment
 699                          * (these 'prefix_len' bytes are sent out later
 700                          * together with the actual payload) */
 701                         prefix_len = do_ssl3_write(s, type, buf, 0, 1);
 702                         if (prefix_len <= 0)
 703                                 goto err;
 704
 705                         if (prefix_len >
 706                 (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD))
 707                                 {
 708                                 /* insufficient space */
 709                                 SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
 710                                 goto err;
 711                                 }
 712                         }
 713
 714                 s->s3->empty_fragment_done = 1;
 715                 }
 716
 717         if (create_empty_fragment)
 718                 {
 719 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
 720                 /* extra fragment would be couple of cipher blocks,
 721                  * which would be multiple of SSL3_ALIGN_PAYLOAD, so
 722                  * if we want to align the real payload, then we can
 723                  * just pretent we simply have two headers. */
 724                 align = (long)wb->buf + 2*SSL3_RT_HEADER_LENGTH;
 725                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
 726 #endif
 727                 p = wb->buf + align;
 728                 wb->offset  = align;
 729                 }
 730         else if (prefix_len)
 731                 {
 732                 p = wb->buf + wb->offset + prefix_len;
 733                 }
 734         else
 735                 {
 736 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
 737                 align = (long)wb->buf + SSL3_RT_HEADER_LENGTH;
 738                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
 739 #endif
 740                 p = wb->buf + align;
 741                 wb->offset  = align;
 742                 }
 743
 744         /* write the header */
 745
 746         *(p++)=type&0xff;
 747         wr->type=type;
 748
 749         *(p++)=(s->version>>8);
 750         /* Some servers hang if iniatial client hello is larger than 256
 751          * bytes and record version number > TLS 1.0
 752          */
 753         if (s->state == SSL3_ST_CW_CLNT_HELLO_B
 754                                 && !s->renegotiate
 755                                 && TLS1_get_version(s) > TLS1_VERSION)
 756                 *(p++) = 0x1;
 757         else
 758                 *(p++)=s->version&0xff;
 759
 760         /* field where we are to write out packet length */
 761         plen=p;
 762         p+=2;
 763         /* Explicit IV length, block ciphers and TLS version 1.1 or later */
 764         if (s->enc_write_ctx && s->version >= TLS1_1_VERSION)
 765                 {
 766                 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
 767                 if (mode == EVP_CIPH_CBC_MODE)
 768                         {
 769                         eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
 770                         if (eivlen <= 1)
 771                                 eivlen = 0;
 772                         }
 773                 /* Need explicit part of IV for GCM mode */
 774                 else if (mode == EVP_CIPH_GCM_MODE)
 775                         eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
 776                 else
 777                         eivlen = 0;
 778                 }
 779         else
 780                 eivlen = 0;
 781
 782         /* lets setup the record stuff. */
 783         wr->data=p + eivlen;
 784         wr->length=(int)len;
 785         wr->input=(unsigned char *)buf;
 786
 787         /* we now 'read' from wr->input, wr->length bytes into
 788          * wr->data */
 789
 790         /* first we compress */
 791         if (s->compress != NULL)
 792                 {
 793                 if (!ssl3_do_compress(s))
 794                         {
 795                         SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
 796                         goto err;
 797                         }
 798                 }
 799         else
 800                 {
 801                 memcpy(wr->data,wr->input,wr->length);
 802                 wr->input=wr->data;
 803                 }
 804
 805         /* we should still have the output to wr->data and the input
 806          * from wr->input.  Length should be wr->length.
 807          * wr->data still points in the wb->buf */
 808
 809         if (mac_size != 0)
 810                 {
 811                 if (s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0)
 812                         goto err;
 813                 wr->length+=mac_size;
 814                 }
 815
 816         wr->input=p;
 817         wr->data=p;
 818
 819         if (eivlen)
 820                 {
 821         /*      if (RAND_pseudo_bytes(p, eivlen) <= 0)
 822                         goto err; */
 823                 wr->length += eivlen;
 824                 }
 825
 826         /* ssl3_enc can only have an error on read */
 827         s->method->ssl3_enc->enc(s,1);
 828
 829         /* record length after mac and block padding */
 830         s2n(wr->length,plen);
 831
 832         if (s->msg_callback)
 833                 s->msg_callback(1, 0, SSL3_RT_HEADER, plen - 5, 5, s, s->msg_callback_arg);
 834
 835         /* we should now have
 836          * wr->data pointing to the encrypted data, which is
 837          * wr->length long */
 838         wr->type=type; /* not needed but helps for debugging */
 839         wr->length+=SSL3_RT_HEADER_LENGTH;
 840
 841         if (create_empty_fragment)
 842                 {
 843                 /* we are in a recursive call;
 844                  * just return the length, don't write out anything here
 845                  */
 846                 return wr->length;
 847                 }
 848
 849         /* now let's set up wb */
 850         wb->left = prefix_len + wr->length;
 851
 852         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
 853         s->s3->wpend_tot=len;
 854         s->s3->wpend_buf=buf;
 855         s->s3->wpend_type=type;
 856         s->s3->wpend_ret=len;
 857
 858         /* we now just need to write the buffer */
 859         return ssl3_write_pending(s,type,buf,len);
 860 err:
 861         return -1;
 862         }
 863
 864 /* if s->s3->wbuf.left != 0, we need to call this */
 865 int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
 866         unsigned int len)
 867         {
 868         int i;
 869         SSL3_BUFFER *wb=&(s->s3->wbuf);
 870
 871 /* XXXX */
 872         if ((s->s3->wpend_tot > (int)len)
 873                 || ((s->s3->wpend_buf != buf) &&
 874                         !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER))
 875                 || (s->s3->wpend_type != type))
 876                 {
 877                 SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
 878                 return(-1);
 879                 }
 880
 881         for (;;)
 882                 {
 883                 clear_sys_error();
 884                 if (s->wbio != NULL)
 885                         {
 886                         s->rwstate=SSL_WRITING;
 887                         i=BIO_write(s->wbio,
 888                                 (char *)&(wb->buf[wb->offset]),
 889                                 (unsigned int)wb->left);
 890                         }
 891                 else
 892                         {
 893                         SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
 894                         i= -1;
 895                         }
 896                 if (i == wb->left)
 897                         {
 898                         wb->left=0;
 899                         wb->offset+=i;
 900                         if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
 901                             SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
 902                                 ssl3_release_write_buffer(s);
 903                         s->rwstate=SSL_NOTHING;
 904                         return(s->s3->wpend_ret);
 905                         }
 906                 else if (i <= 0) {
 907                         if (s->version == DTLS1_VERSION ||
 908                             s->version == DTLS1_BAD_VER) {
 909                                 /* For DTLS, just drop it. That's kind of the whole
 910                                    point in using a datagram service */
 911                                 wb->left = 0;
 912                         }
 913                         return(i);
 914                 }
 915                 wb->offset+=i;
 916                 wb->left-=i;
 917                 }
 918         }
 919
 920 /* Return up to 'len' payload bytes received in 'type' records.
 921  * 'type' is one of the following:
 922  *
 923  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 924  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 925  *   -  0 (during a shutdown, no data has to be returned)
 926  *
 927  * If we don't have stored data to work from, read a SSL/TLS record first
 928  * (possibly multiple records if we still don't have anything to return).
 929  *
 930  * This function must handle any surprises the peer may have for us, such as
 931  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 932  * a surprise, but handled as if it were), or renegotiation requests.
 933  * Also if record payloads contain fragments too small to process, we store
 934  * them until there is enough for the respective protocol (the record protocol
 935  * may use arbitrary fragmentation and even interleaving):
 936  *     Change cipher spec protocol
 937  *             just 1 byte needed, no need for keeping anything stored
 938  *     Alert protocol
 939  *             2 bytes needed (AlertLevel, AlertDescription)
 940  *     Handshake protocol
 941  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 942  *             to detect unexpected Client Hello and Hello Request messages
 943  *             here, anything else is handled by higher layers
 944  *     Application data protocol
 945  *             none of our business
 946  */
 947 int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 948         {
 949         int al,i,j,ret;
 950         unsigned int n;
 951         SSL3_RECORD *rr;
 952         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 953
 954         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 955                 if (!ssl3_setup_read_buffer(s))
 956                         return(-1);
 957
 958         if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE) && type) ||
 959             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 960                 {
 961                 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
 962                 return -1;
 963                 }
 964
 965         if ((type == SSL3_RT_HANDSHAKE) && (s->s3->handshake_fragment_len > 0))
 966                 /* (partially) satisfy request from storage */
 967                 {
 968                 unsigned char *src = s->s3->handshake_fragment;
 969                 unsigned char *dst = buf;
 970                 unsigned int k;
 971
 972                 /* peek == 0 */
 973                 n = 0;
 974                 while ((len > 0) && (s->s3->handshake_fragment_len > 0))
 975                         {
 976                         *dst++ = *src++;
 977                         len--; s->s3->handshake_fragment_len--;
 978                         n++;
 979                         }
 980                 /* move any remaining fragment bytes: */
 981                 for (k = 0; k < s->s3->handshake_fragment_len; k++)
 982                         s->s3->handshake_fragment[k] = *src++;
 983                 return n;
 984         }
 985
 986         /* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 987
 988         if (!s->in_handshake && SSL_in_init(s))
 989                 {
 990                 /* type == SSL3_RT_APPLICATION_DATA */
 991                 i=s->handshake_func(s);
 992                 if (i < 0) return(i);
 993                 if (i == 0)
 994                         {
 995                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 996                         return(-1);
 997                         }
 998                 }
 999 start:
1000         s->rwstate=SSL_NOTHING;
1001
1002         /* s->s3->rrec.type         - is the type of record
1003          * s->s3->rrec.data,    - data
1004          * s->s3->rrec.off,     - offset into 'data' for next read
1005          * s->s3->rrec.length,  - number of bytes. */
1006         rr = &(s->s3->rrec);
1007
1008         /* get new packet if necessary */
1009         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
1010                 {
1011                 ret=ssl3_get_record(s);
1012                 if (ret <= 0) return(ret);
1013                 }
1014
1015         /* we now have a packet which can be read and processed */
1016
1017         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
1018                                        * reset by ssl3_get_finished */
1019                 && (rr->type != SSL3_RT_HANDSHAKE))
1020                 {
1021                 al=SSL_AD_UNEXPECTED_MESSAGE;
1022                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
1023                 goto f_err;
1024                 }
1025
1026         /* If the other end has shut down, throw anything we read away
1027          * (even in 'peek' mode) */
1028         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
1029                 {
1030                 rr->length=0;
1031                 s->rwstate=SSL_NOTHING;
1032                 return(0);
1033                 }
1034
1035
1036         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
1037                 {
1038                 /* make sure that we are not getting application data when we
1039                  * are doing a handshake for the first time */
1040                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
1041                         (s->enc_read_ctx == NULL))
1042                         {
1043                         al=SSL_AD_UNEXPECTED_MESSAGE;
1044                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
1045                         goto f_err;
1046                         }
1047
1048                 if (len <= 0) return(len);
1049
1050                 if ((unsigned int)len > rr->length)
1051                         n = rr->length;
1052                 else
1053                         n = (unsigned int)len;
1054
1055                 memcpy(buf,&(rr->data[rr->off]),n);
1056                 if (!peek)
1057                         {
1058                         rr->length-=n;
1059                         rr->off+=n;
1060                         if (rr->length == 0)
1061                                 {
1062                                 s->rstate=SSL_ST_READ_HEADER;
1063                                 rr->off=0;
1064                                 if (s->mode & SSL_MODE_RELEASE_BUFFERS)
1065                                         ssl3_release_read_buffer(s);
1066                                 }
1067                         }
1068                 return(n);
1069                 }
1070
1071
1072         /* If we get here, then type != rr->type; if we have a handshake
1073          * message, then it was unexpected (Hello Request or Client Hello). */
1074
1075         /* In case of record types for which we have 'fragment' storage,
1076          * fill that so that we can process the data at a fixed place.
1077          */
1078                 {
1079                 unsigned int dest_maxlen = 0;
1080                 unsigned char *dest = NULL;
1081                 unsigned int *dest_len = NULL;
1082
1083                 if (rr->type == SSL3_RT_HANDSHAKE)
1084                         {
1085                         dest_maxlen = sizeof s->s3->handshake_fragment;
1086                         dest = s->s3->handshake_fragment;
1087                         dest_len = &s->s3->handshake_fragment_len;
1088                         }
1089                 else if (rr->type == SSL3_RT_ALERT)
1090                         {
1091                         dest_maxlen = sizeof s->s3->alert_fragment;
1092                         dest = s->s3->alert_fragment;
1093                         dest_len = &s->s3->alert_fragment_len;
1094                         }
1095 #ifndef OPENSSL_NO_HEARTBEATS
1096                 else if (rr->type == TLS1_RT_HEARTBEAT)
1097                         {
1098                         tls1_process_heartbeat(s);
1099
1100                         /* Exit and notify application to read again */
1101                         rr->length = 0;
1102                         s->rwstate=SSL_READING;
1103                         BIO_clear_retry_flags(SSL_get_rbio(s));
1104                         BIO_set_retry_read(SSL_get_rbio(s));
1105                         return(-1);
1106                         }
1107 #endif
1108
1109                 if (dest_maxlen > 0)
1110                         {
1111                         n = dest_maxlen - *dest_len; /* available space in 'dest' */
1112                         if (rr->length < n)
1113                                 n = rr->length; /* available bytes */
1114
1115                         /* now move 'n' bytes: */
1116                         while (n-- > 0)
1117                                 {
1118                                 dest[(*dest_len)++] = rr->data[rr->off++];
1119                                 rr->length--;
1120                                 }
1121
1122                         if (*dest_len < dest_maxlen)
1123                                 goto start; /* fragment was too small */
1124                         }
1125                 }
1126
1127         /* s->s3->handshake_fragment_len == 4  iff  rr->type == SSL3_RT_HANDSHAKE;
1128          * s->s3->alert_fragment_len == 2      iff  rr->type == SSL3_RT_ALERT.
1129          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1130
1131         /* If we are a client, check for an incoming 'Hello Request': */
1132         if ((!s->server) &&
1133                 (s->s3->handshake_fragment_len >= 4) &&
1134                 (s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1135                 (s->session != NULL) && (s->session->cipher != NULL))
1136                 {
1137                 s->s3->handshake_fragment_len = 0;
1138
1139                 if ((s->s3->handshake_fragment[1] != 0) ||
1140                         (s->s3->handshake_fragment[2] != 0) ||
1141                         (s->s3->handshake_fragment[3] != 0))
1142                         {
1143                         al=SSL_AD_DECODE_ERROR;
1144                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1145                         goto f_err;
1146                         }
1147
1148                 if (s->msg_callback)
1149                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->s3->handshake_fragment, 4, s, s->msg_callback_arg);
1150
1151                 if (SSL_is_init_finished(s) &&
1152                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1153                         !s->s3->renegotiate)
1154                         {
1155                         ssl3_renegotiate(s);
1156                         if (ssl3_renegotiate_check(s))
1157                                 {
1158                                 i=s->handshake_func(s);
1159                                 if (i < 0) return(i);
1160                                 if (i == 0)
1161                                         {
1162                                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1163                                         return(-1);
1164                                         }
1165
1166                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1167                                         {
1168                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1169                                                 {
1170                                                 BIO *bio;
1171                                                 /* In the case where we try to read application data,
1172                                                  * but we trigger an SSL handshake, we return -1 with
1173                                                  * the retry option set.  Otherwise renegotiation may
1174                                                  * cause nasty problems in the blocking world */
1175                                                 s->rwstate=SSL_READING;
1176                                                 bio=SSL_get_rbio(s);
1177                                                 BIO_clear_retry_flags(bio);
1178                                                 BIO_set_retry_read(bio);
1179                                                 return(-1);
1180                                                 }
1181                                         }
1182                                 }
1183                         }
1184                 /* we either finished a handshake or ignored the request,
1185                  * now try again to obtain the (application) data we were asked for */
1186                 goto start;
1187                 }
1188         /* If we are a server and get a client hello when renegotiation isn't
1189          * allowed send back a no renegotiation alert and carry on.
1190          * WARNING: experimental code, needs reviewing (steve)
1191          */
1192         if (s->server &&
1193                 SSL_is_init_finished(s) &&
1194                 !s->s3->send_connection_binding &&
1195                 (s->version > SSL3_VERSION) &&
1196                 (s->s3->handshake_fragment_len >= 4) &&
1197                 (s->s3->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) &&
1198                 (s->session != NULL) && (s->session->cipher != NULL) &&
1199                 !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
1200
1201                 {
1202                 /*s->s3->handshake_fragment_len = 0;*/
1203                 rr->length = 0;
1204                 ssl3_send_alert(s,SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
1205                 goto start;
1206                 }
1207         if (s->s3->alert_fragment_len >= 2)
1208                 {
1209                 int alert_level = s->s3->alert_fragment[0];
1210                 int alert_descr = s->s3->alert_fragment[1];
1211
1212                 s->s3->alert_fragment_len = 0;
1213
1214                 if (s->msg_callback)
1215                         s->msg_callback(0, s->version, SSL3_RT_ALERT, s->s3->alert_fragment, 2, s, s->msg_callback_arg);
1216
1217                 if (s->info_callback != NULL)
1218                         cb=s->info_callback;
1219                 else if (s->ctx->info_callback != NULL)
1220                         cb=s->ctx->info_callback;
1221
1222                 if (cb != NULL)
1223                         {
1224                         j = (alert_level << 8) | alert_descr;
1225                         cb(s, SSL_CB_READ_ALERT, j);
1226                         }
1227
1228                 if (alert_level == 1) /* warning */
1229                         {
1230                         s->s3->warn_alert = alert_descr;
1231                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1232                                 {
1233                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1234                                 return(0);
1235                                 }
1236                         /* This is a warning but we receive it if we requested
1237                          * renegotiation and the peer denied it. Terminate with
1238                          * a fatal alert because if application tried to
1239                          * renegotiatie it presumably had a good reason and
1240                          * expects it to succeed.
1241                          *
1242                          * In future we might have a renegotiation where we
1243                          * don't care if the peer refused it where we carry on.
1244                          */
1245                         else if (alert_descr == SSL_AD_NO_RENEGOTIATION)
1246                                 {
1247                                 al = SSL_AD_HANDSHAKE_FAILURE;
1248                                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_NO_RENEGOTIATION);
1249                                 goto f_err;
1250                                 }
1251 #ifdef SSL_AD_MISSING_SRP_USERNAME
1252                         else if (alert_descr == SSL_AD_MISSING_SRP_USERNAME)
1253                                 return(0);
1254 #endif
1255                         }
1256                 else if (alert_level == 2) /* fatal */
1257                         {
1258                         char tmp[16];
1259
1260                         s->rwstate=SSL_NOTHING;
1261                         s->s3->fatal_alert = alert_descr;
1262                         SSLerr(SSL_F_SSL3_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1263                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1264                         ERR_add_error_data(2,"SSL alert number ",tmp);
1265                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1266                         SSL_CTX_remove_session(s->ctx,s->session);
1267                         return(0);
1268                         }
1269                 else
1270                         {
1271                         al=SSL_AD_ILLEGAL_PARAMETER;
1272                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1273                         goto f_err;
1274                         }
1275
1276                 goto start;
1277                 }
1278
1279         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1280                 {
1281                 s->rwstate=SSL_NOTHING;
1282                 rr->length=0;
1283                 return(0);
1284                 }
1285
1286         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1287                 {
1288                 /* 'Change Cipher Spec' is just a single byte, so we know
1289                  * exactly what the record payload has to look like */
1290                 if (    (rr->length != 1) || (rr->off != 0) ||
1291                         (rr->data[0] != SSL3_MT_CCS))
1292                         {
1293                         al=SSL_AD_ILLEGAL_PARAMETER;
1294                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1295                         goto f_err;
1296                         }
1297
1298                 /* Check we have a cipher to change to */
1299                 if (s->s3->tmp.new_cipher == NULL)
1300                         {
1301                         al=SSL_AD_UNEXPECTED_MESSAGE;
1302                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
1303                         goto f_err;
1304                         }
1305
1306                 rr->length=0;
1307
1308                 if (s->msg_callback)
1309                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, s->msg_callback_arg);
1310
1311                 s->s3->change_cipher_spec=1;
1312                 if (!ssl3_do_change_cipher_spec(s))
1313                         goto err;
1314                 else
1315                         goto start;
1316                 }
1317
1318         /* Unexpected handshake message (Client Hello, or protocol violation) */
1319         if ((s->s3->handshake_fragment_len >= 4) &&     !s->in_handshake)
1320                 {
1321                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1322                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1323                         {
1324 #if 0 /* worked only because C operator preferences are not as expected (and
1325        * because this is not really needed for clients except for detecting
1326        * protocol violations): */
1327                         s->state=SSL_ST_BEFORE|(s->server)
1328                                 ?SSL_ST_ACCEPT
1329                                 :SSL_ST_CONNECT;
1330 #else
1331                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1332 #endif
1333                         s->renegotiate=1;
1334                         s->new_session=1;
1335                         }
1336                 i=s->handshake_func(s);
1337                 if (i < 0) return(i);
1338                 if (i == 0)
1339                         {
1340                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1341                         return(-1);
1342                         }
1343
1344                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1345                         {
1346                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1347                                 {
1348                                 BIO *bio;
1349                                 /* In the case where we try to read application data,
1350                                  * but we trigger an SSL handshake, we return -1 with
1351                                  * the retry option set.  Otherwise renegotiation may
1352                                  * cause nasty problems in the blocking world */
1353                                 s->rwstate=SSL_READING;
1354                                 bio=SSL_get_rbio(s);
1355                                 BIO_clear_retry_flags(bio);
1356                                 BIO_set_retry_read(bio);
1357                                 return(-1);
1358                                 }
1359                         }
1360                 goto start;
1361                 }
1362
1363         switch (rr->type)
1364                 {
1365         default:
1366 #ifndef OPENSSL_NO_TLS
1367                 /* TLS up to v1.1 just ignores unknown message types:
1368                  * TLS v1.2 give an unexpected message alert.
1369                  */
1370                 if (s->version >= TLS1_VERSION && s->version <= TLS1_1_VERSION)
1371                         {
1372                         rr->length = 0;
1373                         goto start;
1374                         }
1375 #endif
1376                 al=SSL_AD_UNEXPECTED_MESSAGE;
1377                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1378                 goto f_err;
1379         case SSL3_RT_CHANGE_CIPHER_SPEC:
1380         case SSL3_RT_ALERT:
1381         case SSL3_RT_HANDSHAKE:
1382                 /* we already handled all of these, with the possible exception
1383                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1384                  * should not happen when type != rr->type */
1385                 al=SSL_AD_UNEXPECTED_MESSAGE;
1386                 SSLerr(SSL_F_SSL3_READ_BYTES,ERR_R_INTERNAL_ERROR);
1387                 goto f_err;
1388         case SSL3_RT_APPLICATION_DATA:
1389                 /* At this point, we were expecting handshake data,
1390                  * but have application data.  If the library was
1391                  * running inside ssl3_read() (i.e. in_read_app_data
1392                  * is set) and it makes sense to read application data
1393                  * at this point (session renegotiation not yet started),
1394                  * we will indulge it.
1395                  */
1396                 if (s->s3->in_read_app_data &&
1397                         (s->s3->total_renegotiations != 0) &&
1398                         ((
1399                                 (s->state & SSL_ST_CONNECT) &&
1400                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1401                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1402                                 ) || (
1403                                         (s->state & SSL_ST_ACCEPT) &&
1404                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1405                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1406                                         )
1407                                 ))
1408                         {
1409                         s->s3->in_read_app_data=2;
1410                         return(-1);
1411                         }
1412                 else
1413                         {
1414                         al=SSL_AD_UNEXPECTED_MESSAGE;
1415                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1416                         goto f_err;
1417                         }
1418                 }
1419         /* not reached */
1420
1421 f_err:
1422         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1423 err:
1424         return(-1);
1425         }
1426
1427 int ssl3_do_change_cipher_spec(SSL *s)
1428         {
1429         int i;
1430         const char *sender;
1431         int slen;
1432
1433         if (s->state & SSL_ST_ACCEPT)
1434                 i=SSL3_CHANGE_CIPHER_SERVER_READ;
1435         else
1436                 i=SSL3_CHANGE_CIPHER_CLIENT_READ;
1437
1438         if (s->s3->tmp.key_block == NULL)
1439                 {
1440                 if (s->session == NULL)
1441                         {
1442                         /* might happen if dtls1_read_bytes() calls this */
1443                         SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_CCS_RECEIVED_EARLY);
1444                         return (0);
1445                         }
1446
1447                 s->session->cipher=s->s3->tmp.new_cipher;
1448                 if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
1449                 }
1450
1451         if (!s->method->ssl3_enc->change_cipher_state(s,i))
1452                 return(0);
1453
1454         /* we have to record the message digest at
1455          * this point so we can get it before we read
1456          * the finished message */
1457         if (s->state & SSL_ST_CONNECT)
1458                 {
1459                 sender=s->method->ssl3_enc->server_finished_label;
1460                 slen=s->method->ssl3_enc->server_finished_label_len;
1461                 }
1462         else
1463                 {
1464                 sender=s->method->ssl3_enc->client_finished_label;
1465                 slen=s->method->ssl3_enc->client_finished_label_len;
1466                 }
1467
1468         s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
1469                 sender,slen,s->s3->tmp.peer_finish_md);
1470
1471         return(1);
1472         }
1473
1474 int ssl3_send_alert(SSL *s, int level, int desc)
1475         {
1476         /* Map tls/ssl alert value to correct one */
1477         desc=s->method->ssl3_enc->alert_value(desc);
1478         if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION)
1479                 desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have protocol_version alerts */
1480         if (desc < 0) return -1;
1481         /* If a fatal one, remove from cache */
1482         if ((level == 2) && (s->session != NULL))
1483                 SSL_CTX_remove_session(s->ctx,s->session);
1484
1485         s->s3->alert_dispatch=1;
1486         s->s3->send_alert[0]=level;
1487         s->s3->send_alert[1]=desc;
1488         if (s->s3->wbuf.left == 0) /* data still being written out? */
1489                 return s->method->ssl_dispatch_alert(s);
1490         /* else data is still being written out, we will get written
1491          * some time in the future */
1492         return -1;
1493         }
1494
1495 int ssl3_dispatch_alert(SSL *s)
1496         {
1497         int i,j;
1498         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1499
1500         s->s3->alert_dispatch=0;
1501         i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0);
1502         if (i <= 0)
1503                 {
1504                 s->s3->alert_dispatch=1;
1505                 }
1506         else
1507                 {
1508                 /* Alert sent to BIO.  If it is important, flush it now.
1509                  * If the message does not get sent due to non-blocking IO,
1510                  * we will not worry too much. */
1511                 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1512                         (void)BIO_flush(s->wbio);
1513
1514                 if (s->msg_callback)
1515                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s, s->msg_callback_arg);
1516
1517                 if (s->info_callback != NULL)
1518                         cb=s->info_callback;
1519                 else if (s->ctx->info_callback != NULL)
1520                         cb=s->ctx->info_callback;
1521
1522                 if (cb != NULL)
1523                         {
1524                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1525                         cb(s,SSL_CB_WRITE_ALERT,j);
1526                         }
1527                 }
1528         return(i);
1529         }