ssl/s3_pkt.c

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