ssl/s3_pkt.c

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