ssl/s3_pkt.c

   1 /* ssl/s3_pkt.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58 /* ====================================================================
  59  * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
  60  *
  61  * Redistribution and use in source and binary forms, with or without
  62  * modification, are permitted provided that the following conditions
  63  * are met:
  64  *
  65  * 1. Redistributions of source code must retain the above copyright
  66  *    notice, this list of conditions and the following disclaimer.
  67  *
  68  * 2. Redistributions in binary form must reproduce the above copyright
  69  *    notice, this list of conditions and the following disclaimer in
  70  *    the documentation and/or other materials provided with the
  71  *    distribution.
  72  *
  73  * 3. All advertising materials mentioning features or use of this
  74  *    software must display the following acknowledgment:
  75  *    "This product includes software developed by the OpenSSL Project
  76  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  77  *
  78  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  79  *    endorse or promote products derived from this software without
  80  *    prior written permission. For written permission, please contact
  81  *    openssl-core@openssl.org.
  82  *
  83  * 5. Products derived from this software may not be called "OpenSSL"
  84  *    nor may "OpenSSL" appear in their names without prior written
  85  *    permission of the OpenSSL Project.
  86  *
  87  * 6. Redistributions of any form whatsoever must retain the following
  88  *    acknowledgment:
  89  *    "This product includes software developed by the OpenSSL Project
  90  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  91  *
  92  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  93  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  94  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  95  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  96  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  97  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  98  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  99  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 100  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 101  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 102  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 103  * OF THE POSSIBILITY OF SUCH DAMAGE.
 104  * ====================================================================
 105  *
 106  * This product includes cryptographic software written by Eric Young
 107  * (eay@cryptsoft.com).  This product includes software written by Tim
 108  * Hudson (tjh@cryptsoft.com).
 109  *
 110  */
 111
 112 #include <stdio.h>
 113 #include <limits.h>
 114 #include <errno.h>
 115 #define USE_SOCKETS
 116 #include "ssl_locl.h"
 117 #include <openssl/evp.h>
 118 #include <openssl/buffer.h>
 119
 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 /* MAX_EMPTY_RECORDS defines the number of consecutive, empty records that will
 276  * be processed per call to ssl3_get_record. Without this limit an attacker
 277  * could send empty records at a faster rate than we can process and cause
 278  * ssl3_get_record to loop forever. */
 279 #define MAX_EMPTY_RECORDS 32
 280
 281 /* Call this to get a new input record.
 282  * It will return <= 0 if more data is needed, normally due to an error
 283  * or non-blocking IO.
 284  * When it finishes, one packet has been decoded and can be found in
 285  * ssl->s3->rrec.type    - is the type of record
 286  * ssl->s3->rrec.data,   - data
 287  * ssl->s3->rrec.length, - number of bytes
 288  */
 289 /* used only by ssl3_read_bytes */
 290 static int ssl3_get_record(SSL *s)
 291         {
 292         int ssl_major,ssl_minor,al;
 293         int enc_err,n,i,ret= -1;
 294         SSL3_RECORD *rr;
 295         SSL_SESSION *sess;
 296         unsigned char *p;
 297         unsigned char md[EVP_MAX_MD_SIZE];
 298         short version;
 299         unsigned mac_size, orig_len;
 300         size_t extra;
 301         unsigned empty_record_count = 0;
 302
 303         rr= &(s->s3->rrec);
 304         sess=s->session;
 305
 306         if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
 307                 extra=SSL3_RT_MAX_EXTRA;
 308         else
 309                 extra=0;
 310         if (extra && !s->s3->init_extra)
 311                 {
 312                 /* An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
 313                  * set after ssl3_setup_buffers() was done */
 314                 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
 315                 return -1;
 316                 }
 317
 318 again:
 319         /* check if we have the header */
 320         if (    (s->rstate != SSL_ST_READ_BODY) ||
 321                 (s->packet_length < SSL3_RT_HEADER_LENGTH))
 322                 {
 323                 n=ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 324                 if (n <= 0) return(n); /* error or non-blocking */
 325                 s->rstate=SSL_ST_READ_BODY;
 326
 327                 p=s->packet;
 328
 329                 /* Pull apart the header into the SSL3_RECORD */
 330                 rr->type= *(p++);
 331                 ssl_major= *(p++);
 332                 ssl_minor= *(p++);
 333                 version=(ssl_major<<8)|ssl_minor;
 334                 n2s(p,rr->length);
 335 #if 0
 336 fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length);
 337 #endif
 338
 339                 /* Lets check version */
 340                 if (!s->first_packet)
 341                         {
 342                         if (version != s->version)
 343                                 {
 344                                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 345                                 if ((s->version & 0xFF00) == (version & 0xFF00))
 346                                         /* Send back error using their minor version number :-) */
 347                                         s->version = (unsigned short)version;
 348                                 al=SSL_AD_PROTOCOL_VERSION;
 349                                 goto f_err;
 350                                 }
 351                         }
 352
 353                 if ((version>>8) != SSL3_VERSION_MAJOR)
 354                         {
 355                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 356                         goto err;
 357                         }
 358
 359                 if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH)
 360                         {
 361                         al=SSL_AD_RECORD_OVERFLOW;
 362                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 363                         goto f_err;
 364                         }
 365
 366                 /* now s->rstate == SSL_ST_READ_BODY */
 367                 }
 368
 369         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 370
 371         if (rr->length > s->packet_length-SSL3_RT_HEADER_LENGTH)
 372                 {
 373                 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
 374                 i=rr->length;
 375                 n=ssl3_read_n(s,i,i,1);
 376                 if (n <= 0) return(n); /* error or non-blocking io */
 377                 /* now n == rr->length,
 378                  * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */
 379                 }
 380
 381         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 382
 383         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 384          * and we have that many bytes in s->packet
 385          */
 386         rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);
 387
 388         /* ok, we can now read from 's->packet' data into 'rr'
 389          * rr->input points at rr->length bytes, which
 390          * need to be copied into rr->data by either
 391          * the decryption or by the decompression
 392          * When the data is 'copied' into the rr->data buffer,
 393          * rr->input will be pointed at the new buffer */
 394
 395         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 396          * rr->length bytes of encrypted compressed stuff. */
 397
 398         /* check is not needed I believe */
 399         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
 400                 {
 401                 al=SSL_AD_RECORD_OVERFLOW;
 402                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 403                 goto f_err;
 404                 }
 405
 406         /* decrypt in place in 'rr->input' */
 407         rr->data=rr->input;
 408
 409         enc_err = s->method->ssl3_enc->enc(s,0);
 410         /* enc_err is:
 411          *    0: (in non-constant time) if the record is publically invalid.
 412          *    1: if the padding is valid
 413          *    -1: if the padding is invalid */
 414         if (enc_err == 0)
 415                 {
 416                 al=SSL_AD_DECRYPTION_FAILED;
 417                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
 418                 goto f_err;
 419                 }
 420
 421 #ifdef TLS_DEBUG
 422 printf("dec %d\n",rr->length);
 423 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 424 printf("\n");
 425 #endif
 426
 427         /* r->length is now the compressed data plus mac */
 428         if ((sess != NULL) &&
 429             (s->enc_read_ctx != NULL) &&
 430             (EVP_MD_CTX_md(s->read_hash) != NULL))
 431                 {
 432                 /* s->read_hash != NULL => mac_size != -1 */
 433                 unsigned char *mac = NULL;
 434                 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
 435                 mac_size=EVP_MD_CTX_size(s->read_hash);
 436                 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
 437
 438                 /* kludge: *_cbc_remove_padding passes padding length in rr->type */
 439                 orig_len = rr->length+((unsigned int)rr->type>>8);
 440
 441                 /* orig_len is the length of the record before any padding was
 442                  * removed. This is public information, as is the MAC in use,
 443                  * therefore we can safely process the record in a different
 444                  * amount of time if it's too short to possibly contain a MAC.
 445                  */
 446                 if (orig_len < mac_size ||
 447                     /* CBC records must have a padding length byte too. */
 448                     (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
 449                      orig_len < mac_size+1))
 450                         {
 451                         al=SSL_AD_DECODE_ERROR;
 452                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
 453                         goto f_err;
 454                         }
 455
 456                 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
 457                         {
 458                         /* We update the length so that the TLS header bytes
 459                          * can be constructed correctly but we need to extract
 460                          * the MAC in constant time from within the record,
 461                          * without leaking the contents of the padding bytes.
 462                          * */
 463                         mac = mac_tmp;
 464                         ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
 465                         rr->length -= mac_size;
 466                         }
 467                 else
 468                         {
 469                         /* In this case there's no padding, so |orig_len|
 470                          * equals |rec->length| and we checked that there's
 471                          * enough bytes for |mac_size| above. */
 472                         rr->length -= mac_size;
 473                         mac = &rr->data[rr->length];
 474                         }
 475
 476                 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
 477                 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
 478                         enc_err = -1;
 479                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
 480                         enc_err = -1;
 481                 }
 482
 483         if (enc_err < 0)
 484                 {
 485                 /* A separate 'decryption_failed' alert was introduced with TLS 1.0,
 486                  * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 487                  * failure is directly visible from the ciphertext anyway,
 488                  * we should not reveal which kind of error occured -- this
 489                  * might become visible to an attacker (e.g. via a logfile) */
 490                 al=SSL_AD_BAD_RECORD_MAC;
 491                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 492                 goto f_err;
 493                 }
 494
 495         /* r->length is now just compressed */
 496         if (s->expand != NULL)
 497                 {
 498                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
 499                         {
 500                         al=SSL_AD_RECORD_OVERFLOW;
 501                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 502                         goto f_err;
 503                         }
 504                 if (!ssl3_do_uncompress(s))
 505                         {
 506                         al=SSL_AD_DECOMPRESSION_FAILURE;
 507                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
 508                         goto f_err;
 509                         }
 510                 }
 511
 512         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH+extra)
 513                 {
 514                 al=SSL_AD_RECORD_OVERFLOW;
 515                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 516                 goto f_err;
 517                 }
 518
 519         rr->off=0;
 520         /* So at this point the following is true
 521          * ssl->s3->rrec.type   is the type of record
 522          * ssl->s3->rrec.length == number of bytes in record
 523          * ssl->s3->rrec.off    == offset to first valid byte
 524          * ssl->s3->rrec.data   == where to take bytes from, increment
 525          *                         after use :-).
 526          */
 527
 528         /* we have pulled in a full packet so zero things */
 529         s->packet_length=0;
 530
 531         /* just read a 0 length packet */
 532         if (rr->length == 0)
 533                 {
 534                 empty_record_count++;
 535                 if (empty_record_count > MAX_EMPTY_RECORDS)
 536                         {
 537                         al=SSL_AD_UNEXPECTED_MESSAGE;
 538                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_RECORD_TOO_SMALL);
 539                         goto f_err;
 540                         }
 541                 goto again;
 542                 }
 543
 544 #if 0
 545 fprintf(stderr, "Ultimate Record type=%d, Length=%d\n", rr->type, rr->length);
 546 #endif
 547
 548         return(1);
 549
 550 f_err:
 551         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 552 err:
 553         return(ret);
 554         }
 555
 556 int ssl3_do_uncompress(SSL *ssl)
 557         {
 558 #ifndef OPENSSL_NO_COMP
 559         int i;
 560         SSL3_RECORD *rr;
 561
 562         rr= &(ssl->s3->rrec);
 563         i=COMP_expand_block(ssl->expand,rr->comp,
 564                 SSL3_RT_MAX_PLAIN_LENGTH,rr->data,(int)rr->length);
 565         if (i < 0)
 566                 return(0);
 567         else
 568                 rr->length=i;
 569         rr->data=rr->comp;
 570 #endif
 571         return(1);
 572         }
 573
 574 int ssl3_do_compress(SSL *ssl)
 575         {
 576 #ifndef OPENSSL_NO_COMP
 577         int i;
 578         SSL3_RECORD *wr;
 579
 580         wr= &(ssl->s3->wrec);
 581         i=COMP_compress_block(ssl->compress,wr->data,
 582                 SSL3_RT_MAX_COMPRESSED_LENGTH,
 583                 wr->input,(int)wr->length);
 584         if (i < 0)
 585                 return(0);
 586         else
 587                 wr->length=i;
 588
 589         wr->input=wr->data;
 590 #endif
 591         return(1);
 592         }
 593
 594 /* Call this to write data in records of type 'type'
 595  * It will return <= 0 if not all data has been sent or non-blocking IO.
 596  */
 597 int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
 598         {
 599         const unsigned char *buf=buf_;
 600         unsigned int n,nw;
 601         int i,tot;
 602
 603         s->rwstate=SSL_NOTHING;
 604         OPENSSL_assert(s->s3->wnum <= INT_MAX);
 605         tot=s->s3->wnum;
 606         s->s3->wnum=0;
 607
 608         if (SSL_in_init(s) && !s->in_handshake)
 609                 {
 610                 i=s->handshake_func(s);
 611                 if (i < 0) return(i);
 612                 if (i == 0)
 613                         {
 614                         SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 615                         return -1;
 616                         }
 617                 }
 618
 619         /* ensure that if we end up with a smaller value of data to write
 620          * out than the the original len from a write which didn't complete
 621          * for non-blocking I/O and also somehow ended up avoiding
 622          * the check for this in ssl3_write_pending/SSL_R_BAD_WRITE_RETRY as
 623          * it must never be possible to end up with (len-tot) as a large
 624          * number that will then promptly send beyond the end of the users
 625          * buffer ... so we trap and report the error in a way the user
 626          * will notice
 627          */
 628         if (len < tot)
 629                 {
 630                 SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_BAD_LENGTH);
 631                 return(-1);
 632                 }
 633
 634
 635         n=(len-tot);
 636         for (;;)
 637                 {
 638                 if (n > s->max_send_fragment)
 639                         nw=s->max_send_fragment;
 640                 else
 641                         nw=n;
 642
 643                 i=do_ssl3_write(s, type, &(buf[tot]), nw, 0);
 644                 if (i <= 0)
 645                         {
 646                         s->s3->wnum=tot;
 647                         return i;
 648                         }
 649
 650                 if ((i == (int)n) ||
 651                         (type == SSL3_RT_APPLICATION_DATA &&
 652                          (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
 653                         {
 654                         /* next chunk of data should get another prepended empty fragment
 655                          * in ciphersuites with known-IV weakness: */
 656                         s->s3->empty_fragment_done = 0;
 657
 658                         return tot+i;
 659                         }
 660
 661                 n-=i;
 662                 tot+=i;
 663                 }
 664         }
 665
 666 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 667                          unsigned int len, int create_empty_fragment)
 668         {
 669         unsigned char *p,*plen;
 670         int i,mac_size,clear=0;
 671         int prefix_len=0;
 672         long align=0;
 673         SSL3_RECORD *wr;
 674         SSL3_BUFFER *wb=&(s->s3->wbuf);
 675         SSL_SESSION *sess;
 676
 677
 678         /* first check if there is a SSL3_BUFFER still being written
 679          * out.  This will happen with non blocking IO */
 680         if (wb->left != 0)
 681                 return(ssl3_write_pending(s,type,buf,len));
 682
 683         /* If we have an alert to send, lets send it */
 684         if (s->s3->alert_dispatch)
 685                 {
 686                 i=s->method->ssl_dispatch_alert(s);
 687                 if (i <= 0)
 688                         return(i);
 689                 /* if it went, fall through and send more stuff */
 690                 }
 691
 692         if (wb->buf == NULL)
 693                 if (!ssl3_setup_write_buffer(s))
 694                         return -1;
 695
 696         if (len == 0 && !create_empty_fragment)
 697                 return 0;
 698
 699         wr= &(s->s3->wrec);
 700         sess=s->session;
 701
 702         if (    (sess == NULL) ||
 703                 (s->enc_write_ctx == NULL) ||
 704                 (EVP_MD_CTX_md(s->write_hash) == NULL))
 705                 clear=1;
 706
 707         if (clear)
 708                 mac_size=0;
 709         else
 710                 {
 711                 mac_size=EVP_MD_CTX_size(s->write_hash);
 712                 if (mac_size < 0)
 713                         goto err;
 714                 }
 715
 716         /* 'create_empty_fragment' is true only when this function calls itself */
 717         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done)
 718                 {
 719                 /* countermeasure against known-IV weakness in CBC ciphersuites
 720                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
 721
 722                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
 723                         {
 724                         /* recursive function call with 'create_empty_fragment' set;
 725                          * this prepares and buffers the data for an empty fragment
 726                          * (these 'prefix_len' bytes are sent out later
 727                          * together with the actual payload) */
 728                         prefix_len = do_ssl3_write(s, type, buf, 0, 1);
 729                         if (prefix_len <= 0)
 730                                 goto err;
 731
 732                         if (prefix_len >
 733                 (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD))
 734                                 {
 735                                 /* insufficient space */
 736                                 SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
 737                                 goto err;
 738                                 }
 739                         }
 740
 741                 s->s3->empty_fragment_done = 1;
 742                 }
 743
 744         if (create_empty_fragment)
 745                 {
 746 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
 747                 /* extra fragment would be couple of cipher blocks,
 748                  * which would be multiple of SSL3_ALIGN_PAYLOAD, so
 749                  * if we want to align the real payload, then we can
 750                  * just pretent we simply have two headers. */
 751                 align = (long)wb->buf + 2*SSL3_RT_HEADER_LENGTH;
 752                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
 753 #endif
 754                 p = wb->buf + align;
 755                 wb->offset  = align;
 756                 }
 757         else if (prefix_len)
 758                 {
 759                 p = wb->buf + wb->offset + prefix_len;
 760                 }
 761         else
 762                 {
 763 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
 764                 align = (long)wb->buf + SSL3_RT_HEADER_LENGTH;
 765                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
 766 #endif
 767                 p = wb->buf + align;
 768                 wb->offset  = align;
 769                 }
 770
 771         /* write the header */
 772
 773         *(p++)=type&0xff;
 774         wr->type=type;
 775
 776         *(p++)=(s->version>>8);
 777         *(p++)=s->version&0xff;
 778
 779         /* field where we are to write out packet length */
 780         plen=p;
 781         p+=2;
 782
 783         /* lets setup the record stuff. */
 784         wr->data=p;
 785         wr->length=(int)len;
 786         wr->input=(unsigned char *)buf;
 787
 788         /* we now 'read' from wr->input, wr->length bytes into
 789          * wr->data */
 790
 791         /* first we compress */
 792         if (s->compress != NULL)
 793                 {
 794                 if (!ssl3_do_compress(s))
 795                         {
 796                         SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
 797                         goto err;
 798                         }
 799                 }
 800         else
 801                 {
 802                 memcpy(wr->data,wr->input,wr->length);
 803                 wr->input=wr->data;
 804                 }
 805
 806         /* we should still have the output to wr->data and the input
 807          * from wr->input.  Length should be wr->length.
 808          * wr->data still points in the wb->buf */
 809
 810         if (mac_size != 0)
 811                 {
 812                 if (s->method->ssl3_enc->mac(s,&(p[wr->length]),1) < 0)
 813                         goto err;
 814                 wr->length+=mac_size;
 815                 wr->input=p;
 816                 wr->data=p;
 817                 }
 818
 819         if(s->method->ssl3_enc->enc(s,1)<1) goto err;
 820
 821         /* record length after mac and block padding */
 822         s2n(wr->length,plen);
 823
 824         /* we should now have
 825          * wr->data pointing to the encrypted data, which is
 826          * wr->length long */
 827         wr->type=type; /* not needed but helps for debugging */
 828         wr->length+=SSL3_RT_HEADER_LENGTH;
 829
 830         if (create_empty_fragment)
 831                 {
 832                 /* we are in a recursive call;
 833                  * just return the length, don't write out anything here
 834                  */
 835                 return wr->length;
 836                 }
 837
 838         /* now let's set up wb */
 839         wb->left = prefix_len + wr->length;
 840
 841         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
 842         s->s3->wpend_tot=len;
 843         s->s3->wpend_buf=buf;
 844         s->s3->wpend_type=type;
 845         s->s3->wpend_ret=len;
 846
 847         /* we now just need to write the buffer */
 848         return ssl3_write_pending(s,type,buf,len);
 849 err:
 850         return -1;
 851         }
 852
 853 /* if s->s3->wbuf.left != 0, we need to call this */
 854 int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
 855         unsigned int len)
 856         {
 857         int i;
 858         SSL3_BUFFER *wb=&(s->s3->wbuf);
 859
 860 /* XXXX */
 861         if ((s->s3->wpend_tot > (int)len)
 862                 || ((s->s3->wpend_buf != buf) &&
 863                         !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER))
 864                 || (s->s3->wpend_type != type))
 865                 {
 866                 SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
 867                 return(-1);
 868                 }
 869
 870         for (;;)
 871                 {
 872                 clear_sys_error();
 873                 if (s->wbio != NULL)
 874                         {
 875                         s->rwstate=SSL_WRITING;
 876                         i=BIO_write(s->wbio,
 877                                 (char *)&(wb->buf[wb->offset]),
 878                                 (unsigned int)wb->left);
 879                         }
 880                 else
 881                         {
 882                         SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
 883                         i= -1;
 884                         }
 885                 if (i == wb->left)
 886                         {
 887                         wb->left=0;
 888                         wb->offset+=i;
 889                         if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
 890                             SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
 891                                 ssl3_release_write_buffer(s);
 892                         s->rwstate=SSL_NOTHING;
 893                         return(s->s3->wpend_ret);
 894                         }
 895                 else if (i <= 0) {
 896                         if (s->version == DTLS1_VERSION ||
 897                             s->version == DTLS1_BAD_VER) {
 898                                 /* For DTLS, just drop it. That's kind of the whole
 899                                    point in using a datagram service */
 900                                 wb->left = 0;
 901                         }
 902                         return(i);
 903                 }
 904                 wb->offset+=i;
 905                 wb->left-=i;
 906                 }
 907         }
 908
 909 /* Return up to 'len' payload bytes received in 'type' records.
 910  * 'type' is one of the following:
 911  *
 912  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 913  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 914  *   -  0 (during a shutdown, no data has to be returned)
 915  *
 916  * If we don't have stored data to work from, read a SSL/TLS record first
 917  * (possibly multiple records if we still don't have anything to return).
 918  *
 919  * This function must handle any surprises the peer may have for us, such as
 920  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 921  * a surprise, but handled as if it were), or renegotiation requests.
 922  * Also if record payloads contain fragments too small to process, we store
 923  * them until there is enough for the respective protocol (the record protocol
 924  * may use arbitrary fragmentation and even interleaving):
 925  *     Change cipher spec protocol
 926  *             just 1 byte needed, no need for keeping anything stored
 927  *     Alert protocol
 928  *             2 bytes needed (AlertLevel, AlertDescription)
 929  *     Handshake protocol
 930  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 931  *             to detect unexpected Client Hello and Hello Request messages
 932  *             here, anything else is handled by higher layers
 933  *     Application data protocol
 934  *             none of our business
 935  */
 936 int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 937         {
 938         int al,i,j,ret;
 939         unsigned int n;
 940         SSL3_RECORD *rr;
 941         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 942
 943         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 944                 if (!ssl3_setup_read_buffer(s))
 945                         return(-1);
 946
 947         if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE)) ||
 948             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 949                 {
 950                 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
 951                 return -1;
 952                 }
 953
 954         if ((type == SSL3_RT_HANDSHAKE) && (s->s3->handshake_fragment_len > 0))
 955                 /* (partially) satisfy request from storage */
 956                 {
 957                 unsigned char *src = s->s3->handshake_fragment;
 958                 unsigned char *dst = buf;
 959                 unsigned int k;
 960
 961                 /* peek == 0 */
 962                 n = 0;
 963                 while ((len > 0) && (s->s3->handshake_fragment_len > 0))
 964                         {
 965                         *dst++ = *src++;
 966                         len--; s->s3->handshake_fragment_len--;
 967                         n++;
 968                         }
 969                 /* move any remaining fragment bytes: */
 970                 for (k = 0; k < s->s3->handshake_fragment_len; k++)
 971                         s->s3->handshake_fragment[k] = *src++;
 972                 return n;
 973         }
 974
 975         /* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 976
 977         if (!s->in_handshake && SSL_in_init(s))
 978                 {
 979                 /* type == SSL3_RT_APPLICATION_DATA */
 980                 i=s->handshake_func(s);
 981                 if (i < 0) return(i);
 982                 if (i == 0)
 983                         {
 984                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 985                         return(-1);
 986                         }
 987                 }
 988 start:
 989         s->rwstate=SSL_NOTHING;
 990
 991         /* s->s3->rrec.type         - is the type of record
 992          * s->s3->rrec.data,    - data
 993          * s->s3->rrec.off,     - offset into 'data' for next read
 994          * s->s3->rrec.length,  - number of bytes. */
 995         rr = &(s->s3->rrec);
 996
 997         /* get new packet if necessary */
 998         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 999                 {
1000                 ret=ssl3_get_record(s);
1001                 if (ret <= 0) return(ret);
1002                 }
1003
1004         /* we now have a packet which can be read and processed */
1005
1006         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
1007                                        * reset by ssl3_get_finished */
1008                 && (rr->type != SSL3_RT_HANDSHAKE))
1009                 {
1010                 al=SSL_AD_UNEXPECTED_MESSAGE;
1011                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
1012                 goto f_err;
1013                 }
1014
1015         /* If the other end has shut down, throw anything we read away
1016          * (even in 'peek' mode) */
1017         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
1018                 {
1019                 rr->length=0;
1020                 s->rwstate=SSL_NOTHING;
1021                 return(0);
1022                 }
1023
1024
1025         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
1026                 {
1027                 /* make sure that we are not getting application data when we
1028                  * are doing a handshake for the first time */
1029                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
1030                         (s->enc_read_ctx == NULL))
1031                         {
1032                         al=SSL_AD_UNEXPECTED_MESSAGE;
1033                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
1034                         goto f_err;
1035                         }
1036
1037                 if (len <= 0) return(len);
1038
1039                 if ((unsigned int)len > rr->length)
1040                         n = rr->length;
1041                 else
1042                         n = (unsigned int)len;
1043
1044                 memcpy(buf,&(rr->data[rr->off]),n);
1045                 if (!peek)
1046                         {
1047                         rr->length-=n;
1048                         rr->off+=n;
1049                         if (rr->length == 0)
1050                                 {
1051                                 s->rstate=SSL_ST_READ_HEADER;
1052                                 rr->off=0;
1053                                 if (s->mode & SSL_MODE_RELEASE_BUFFERS && s->s3->rbuf.left == 0)
1054                                         ssl3_release_read_buffer(s);
1055                                 }
1056                         }
1057                 return(n);
1058                 }
1059
1060
1061         /* If we get here, then type != rr->type; if we have a handshake
1062          * message, then it was unexpected (Hello Request or Client Hello). */
1063
1064         /* In case of record types for which we have 'fragment' storage,
1065          * fill that so that we can process the data at a fixed place.
1066          */
1067                 {
1068                 unsigned int dest_maxlen = 0;
1069                 unsigned char *dest = NULL;
1070                 unsigned int *dest_len = NULL;
1071
1072                 if (rr->type == SSL3_RT_HANDSHAKE)
1073                         {
1074                         dest_maxlen = sizeof s->s3->handshake_fragment;
1075                         dest = s->s3->handshake_fragment;
1076                         dest_len = &s->s3->handshake_fragment_len;
1077                         }
1078                 else if (rr->type == SSL3_RT_ALERT)
1079                         {
1080                         dest_maxlen = sizeof s->s3->alert_fragment;
1081                         dest = s->s3->alert_fragment;
1082                         dest_len = &s->s3->alert_fragment_len;
1083                         }
1084
1085                 if (dest_maxlen > 0)
1086                         {
1087                         n = dest_maxlen - *dest_len; /* available space in 'dest' */
1088                         if (rr->length < n)
1089                                 n = rr->length; /* available bytes */
1090
1091                         /* now move 'n' bytes: */
1092                         while (n-- > 0)
1093                                 {
1094                                 dest[(*dest_len)++] = rr->data[rr->off++];
1095                                 rr->length--;
1096                                 }
1097
1098                         if (*dest_len < dest_maxlen)
1099                                 goto start; /* fragment was too small */
1100                         }
1101                 }
1102
1103         /* s->s3->handshake_fragment_len == 4  iff  rr->type == SSL3_RT_HANDSHAKE;
1104          * s->s3->alert_fragment_len == 2      iff  rr->type == SSL3_RT_ALERT.
1105          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1106
1107         /* If we are a client, check for an incoming 'Hello Request': */
1108         if ((!s->server) &&
1109                 (s->s3->handshake_fragment_len >= 4) &&
1110                 (s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1111                 (s->session != NULL) && (s->session->cipher != NULL))
1112                 {
1113                 s->s3->handshake_fragment_len = 0;
1114
1115                 if ((s->s3->handshake_fragment[1] != 0) ||
1116                         (s->s3->handshake_fragment[2] != 0) ||
1117                         (s->s3->handshake_fragment[3] != 0))
1118                         {
1119                         al=SSL_AD_DECODE_ERROR;
1120                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1121                         goto f_err;
1122                         }
1123
1124                 if (s->msg_callback)
1125                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->s3->handshake_fragment, 4, s, s->msg_callback_arg);
1126
1127                 if (SSL_is_init_finished(s) &&
1128                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1129                         !s->s3->renegotiate)
1130                         {
1131                         ssl3_renegotiate(s);
1132                         if (ssl3_renegotiate_check(s))
1133                                 {
1134                                 i=s->handshake_func(s);
1135                                 if (i < 0) return(i);
1136                                 if (i == 0)
1137                                         {
1138                                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1139                                         return(-1);
1140                                         }
1141
1142                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1143                                         {
1144                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1145                                                 {
1146                                                 BIO *bio;
1147                                                 /* In the case where we try to read application data,
1148                                                  * but we trigger an SSL handshake, we return -1 with
1149                                                  * the retry option set.  Otherwise renegotiation may
1150                                                  * cause nasty problems in the blocking world */
1151                                                 s->rwstate=SSL_READING;
1152                                                 bio=SSL_get_rbio(s);
1153                                                 BIO_clear_retry_flags(bio);
1154                                                 BIO_set_retry_read(bio);
1155                                                 return(-1);
1156                                                 }
1157                                         }
1158                                 }
1159                         }
1160                 /* we either finished a handshake or ignored the request,
1161                  * now try again to obtain the (application) data we were asked for */
1162                 goto start;
1163                 }
1164         /* If we are a server and get a client hello when renegotiation isn't
1165          * allowed send back a no renegotiation alert and carry on.
1166          * WARNING: experimental code, needs reviewing (steve)
1167          */
1168         if (s->server &&
1169                 SSL_is_init_finished(s) &&
1170                 !s->s3->send_connection_binding &&
1171                 (s->version > SSL3_VERSION) &&
1172                 (s->s3->handshake_fragment_len >= 4) &&
1173                 (s->s3->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) &&
1174                 (s->session != NULL) && (s->session->cipher != NULL) &&
1175                 !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
1176
1177                 {
1178                 /*s->s3->handshake_fragment_len = 0;*/
1179                 rr->length = 0;
1180                 ssl3_send_alert(s,SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
1181                 goto start;
1182                 }
1183         if (s->s3->alert_fragment_len >= 2)
1184                 {
1185                 int alert_level = s->s3->alert_fragment[0];
1186                 int alert_descr = s->s3->alert_fragment[1];
1187
1188                 s->s3->alert_fragment_len = 0;
1189
1190                 if (s->msg_callback)
1191                         s->msg_callback(0, s->version, SSL3_RT_ALERT, s->s3->alert_fragment, 2, s, s->msg_callback_arg);
1192
1193                 if (s->info_callback != NULL)
1194                         cb=s->info_callback;
1195                 else if (s->ctx->info_callback != NULL)
1196                         cb=s->ctx->info_callback;
1197
1198                 if (cb != NULL)
1199                         {
1200                         j = (alert_level << 8) | alert_descr;
1201                         cb(s, SSL_CB_READ_ALERT, j);
1202                         }
1203
1204                 if (alert_level == 1) /* warning */
1205                         {
1206                         s->s3->warn_alert = alert_descr;
1207                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1208                                 {
1209                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1210                                 return(0);
1211                                 }
1212                         /* This is a warning but we receive it if we requested
1213                          * renegotiation and the peer denied it. Terminate with
1214                          * a fatal alert because if application tried to
1215                          * renegotiatie it presumably had a good reason and
1216                          * expects it to succeed.
1217                          *
1218                          * In future we might have a renegotiation where we
1219                          * don't care if the peer refused it where we carry on.
1220                          */
1221                         else if (alert_descr == SSL_AD_NO_RENEGOTIATION)
1222                                 {
1223                                 al = SSL_AD_HANDSHAKE_FAILURE;
1224                                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_NO_RENEGOTIATION);
1225                                 goto f_err;
1226                                 }
1227                         }
1228                 else if (alert_level == 2) /* fatal */
1229                         {
1230                         char tmp[16];
1231
1232                         s->rwstate=SSL_NOTHING;
1233                         s->s3->fatal_alert = alert_descr;
1234                         SSLerr(SSL_F_SSL3_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1235                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1236                         ERR_add_error_data(2,"SSL alert number ",tmp);
1237                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1238                         SSL_CTX_remove_session(s->ctx,s->session);
1239                         return(0);
1240                         }
1241                 else
1242                         {
1243                         al=SSL_AD_ILLEGAL_PARAMETER;
1244                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1245                         goto f_err;
1246                         }
1247
1248                 goto start;
1249                 }
1250
1251         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1252                 {
1253                 s->rwstate=SSL_NOTHING;
1254                 rr->length=0;
1255                 return(0);
1256                 }
1257
1258         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1259                 {
1260                 /* 'Change Cipher Spec' is just a single byte, so we know
1261                  * exactly what the record payload has to look like */
1262                 if (    (rr->length != 1) || (rr->off != 0) ||
1263                         (rr->data[0] != SSL3_MT_CCS))
1264                         {
1265                         al=SSL_AD_ILLEGAL_PARAMETER;
1266                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1267                         goto f_err;
1268                         }
1269
1270                 /* Check we have a cipher to change to */
1271                 if (s->s3->tmp.new_cipher == NULL)
1272                         {
1273                         al=SSL_AD_UNEXPECTED_MESSAGE;
1274                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
1275                         goto f_err;
1276                         }
1277
1278                 if (!(s->s3->flags & SSL3_FLAGS_CCS_OK))
1279                         {
1280                         al=SSL_AD_UNEXPECTED_MESSAGE;
1281                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
1282                         goto f_err;
1283                         }
1284
1285                 s->s3->flags &= ~SSL3_FLAGS_CCS_OK;
1286
1287                 rr->length=0;
1288
1289                 if (s->msg_callback)
1290                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, s->msg_callback_arg);
1291
1292                 s->s3->change_cipher_spec=1;
1293                 if (!ssl3_do_change_cipher_spec(s))
1294                         goto err;
1295                 else
1296                         goto start;
1297                 }
1298
1299         /* Unexpected handshake message (Client Hello, or protocol violation) */
1300         if ((s->s3->handshake_fragment_len >= 4) &&     !s->in_handshake)
1301                 {
1302                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1303                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1304                         {
1305 #if 0 /* worked only because C operator preferences are not as expected (and
1306        * because this is not really needed for clients except for detecting
1307        * protocol violations): */
1308                         s->state=SSL_ST_BEFORE|(s->server)
1309                                 ?SSL_ST_ACCEPT
1310                                 :SSL_ST_CONNECT;
1311 #else
1312                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1313 #endif
1314                         s->new_session=1;
1315                         }
1316                 i=s->handshake_func(s);
1317                 if (i < 0) return(i);
1318                 if (i == 0)
1319                         {
1320                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1321                         return(-1);
1322                         }
1323
1324                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1325                         {
1326                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1327                                 {
1328                                 BIO *bio;
1329                                 /* In the case where we try to read application data,
1330                                  * but we trigger an SSL handshake, we return -1 with
1331                                  * the retry option set.  Otherwise renegotiation may
1332                                  * cause nasty problems in the blocking world */
1333                                 s->rwstate=SSL_READING;
1334                                 bio=SSL_get_rbio(s);
1335                                 BIO_clear_retry_flags(bio);
1336                                 BIO_set_retry_read(bio);
1337                                 return(-1);
1338                                 }
1339                         }
1340                 goto start;
1341                 }
1342
1343         switch (rr->type)
1344                 {
1345         default:
1346 #ifndef OPENSSL_NO_TLS
1347                 /* TLS just ignores unknown message types */
1348                 if (s->version == TLS1_VERSION)
1349                         {
1350                         rr->length = 0;
1351                         goto start;
1352                         }
1353 #endif
1354                 al=SSL_AD_UNEXPECTED_MESSAGE;
1355                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1356                 goto f_err;
1357         case SSL3_RT_CHANGE_CIPHER_SPEC:
1358         case SSL3_RT_ALERT:
1359         case SSL3_RT_HANDSHAKE:
1360                 /* we already handled all of these, with the possible exception
1361                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1362                  * should not happen when type != rr->type */
1363                 al=SSL_AD_UNEXPECTED_MESSAGE;
1364                 SSLerr(SSL_F_SSL3_READ_BYTES,ERR_R_INTERNAL_ERROR);
1365                 goto f_err;
1366         case SSL3_RT_APPLICATION_DATA:
1367                 /* At this point, we were expecting handshake data,
1368                  * but have application data.  If the library was
1369                  * running inside ssl3_read() (i.e. in_read_app_data
1370                  * is set) and it makes sense to read application data
1371                  * at this point (session renegotiation not yet started),
1372                  * we will indulge it.
1373                  */
1374                 if (s->s3->in_read_app_data &&
1375                         (s->s3->total_renegotiations != 0) &&
1376                         ((
1377                                 (s->state & SSL_ST_CONNECT) &&
1378                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1379                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1380                                 ) || (
1381                                         (s->state & SSL_ST_ACCEPT) &&
1382                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1383                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1384                                         )
1385                                 ))
1386                         {
1387                         s->s3->in_read_app_data=2;
1388                         return(-1);
1389                         }
1390                 else
1391                         {
1392                         al=SSL_AD_UNEXPECTED_MESSAGE;
1393                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1394                         goto f_err;
1395                         }
1396                 }
1397         /* not reached */
1398
1399 f_err:
1400         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1401 err:
1402         return(-1);
1403         }
1404
1405 int ssl3_do_change_cipher_spec(SSL *s)
1406         {
1407         int i;
1408         const char *sender;
1409         int slen;
1410
1411         if (s->state & SSL_ST_ACCEPT)
1412                 i=SSL3_CHANGE_CIPHER_SERVER_READ;
1413         else
1414                 i=SSL3_CHANGE_CIPHER_CLIENT_READ;
1415
1416         if (s->s3->tmp.key_block == NULL)
1417                 {
1418                 if (s->session == NULL || s->session->master_key_length == 0)
1419                         {
1420                         /* might happen if dtls1_read_bytes() calls this */
1421                         SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_CCS_RECEIVED_EARLY);
1422                         return (0);
1423                         }
1424
1425                 s->session->cipher=s->s3->tmp.new_cipher;
1426                 if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
1427                 }
1428
1429         if (!s->method->ssl3_enc->change_cipher_state(s,i))
1430                 return(0);
1431
1432         /* we have to record the message digest at
1433          * this point so we can get it before we read
1434          * the finished message */
1435         if (s->state & SSL_ST_CONNECT)
1436                 {
1437                 sender=s->method->ssl3_enc->server_finished_label;
1438                 slen=s->method->ssl3_enc->server_finished_label_len;
1439                 }
1440         else
1441                 {
1442                 sender=s->method->ssl3_enc->client_finished_label;
1443                 slen=s->method->ssl3_enc->client_finished_label_len;
1444                 }
1445
1446         s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
1447                 sender,slen,s->s3->tmp.peer_finish_md);
1448
1449         return(1);
1450         }
1451
1452 int ssl3_send_alert(SSL *s, int level, int desc)
1453         {
1454         /* Map tls/ssl alert value to correct one */
1455         desc=s->method->ssl3_enc->alert_value(desc);
1456         if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION)
1457                 desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have protocol_version alerts */
1458         if (desc < 0) return -1;
1459         /* If a fatal one, remove from cache */
1460         if ((level == 2) && (s->session != NULL))
1461                 SSL_CTX_remove_session(s->ctx,s->session);
1462
1463         s->s3->alert_dispatch=1;
1464         s->s3->send_alert[0]=level;
1465         s->s3->send_alert[1]=desc;
1466         if (s->s3->wbuf.left == 0) /* data still being written out? */
1467                 return s->method->ssl_dispatch_alert(s);
1468         /* else data is still being written out, we will get written
1469          * some time in the future */
1470         return -1;
1471         }
1472
1473 int ssl3_dispatch_alert(SSL *s)
1474         {
1475         int i,j;
1476         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1477
1478         s->s3->alert_dispatch=0;
1479         i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0);
1480         if (i <= 0)
1481                 {
1482                 s->s3->alert_dispatch=1;
1483                 }
1484         else
1485                 {
1486                 /* Alert sent to BIO.  If it is important, flush it now.
1487                  * If the message does not get sent due to non-blocking IO,
1488                  * we will not worry too much. */
1489                 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1490                         (void)BIO_flush(s->wbio);
1491
1492                 if (s->msg_callback)
1493                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s, s->msg_callback_arg);
1494
1495                 if (s->info_callback != NULL)
1496                         cb=s->info_callback;
1497                 else if (s->ctx->info_callback != NULL)
1498                         cb=s->ctx->info_callback;
1499
1500                 if (cb != NULL)
1501                         {
1502                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1503                         cb(s,SSL_CB_WRITE_ALERT,j);
1504                         }
1505                 }
1506         return(i);
1507         }