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