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