crypto/openssl/ssl/d1_both.c

   1 /* ssl/d1_both.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@openssl.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <limits.h>
 117 #include <string.h>
 118 #include <stdio.h>
 119 #include "ssl_locl.h"
 120 #include <openssl/buffer.h>
 121 #include <openssl/rand.h>
 122 #include <openssl/objects.h>
 123 #include <openssl/evp.h>
 124 #include <openssl/x509.h>
 125
 126 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
 127
 128 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
 129                         if ((end) - (start) <= 8) { \
 130                                 long ii; \
 131                                 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
 132                         } else { \
 133                                 long ii; \
 134                                 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
 135                                 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
 136                                 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
 137                         } }
 138
 139 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
 140                         long ii; \
 141                         OPENSSL_assert((msg_len) > 0); \
 142                         is_complete = 1; \
 143                         if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
 144                         if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
 145                                 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
 146
 147 #if 0
 148 #define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
 149                         long ii; \
 150                         printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
 151                         printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
 152                         printf("\n"); }
 153 #endif
 154
 155 static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
 156 static unsigned char bitmask_end_values[]   = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
 157
 158 /* XDTLS:  figure out the right values */
 159 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
 160
 161 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
 162 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
 163         unsigned long frag_len);
 164 static unsigned char *dtls1_write_message_header(SSL *s,
 165         unsigned char *p);
 166 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
 167         unsigned long len, unsigned short seq_num, unsigned long frag_off,
 168         unsigned long frag_len);
 169 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
 170         long max, int *ok);
 171
 172 static hm_fragment *
 173 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
 174         {
 175         hm_fragment *frag = NULL;
 176         unsigned char *buf = NULL;
 177         unsigned char *bitmask = NULL;
 178
 179         frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
 180         if ( frag == NULL)
 181                 return NULL;
 182
 183         if (frag_len)
 184                 {
 185                 buf = (unsigned char *)OPENSSL_malloc(frag_len);
 186                 if ( buf == NULL)
 187                         {
 188                         OPENSSL_free(frag);
 189                         return NULL;
 190                         }
 191                 }
 192
 193         /* zero length fragment gets zero frag->fragment */
 194         frag->fragment = buf;
 195
 196         /* Initialize reassembly bitmask if necessary */
 197         if (reassembly)
 198                 {
 199                 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
 200                 if (bitmask == NULL)
 201                         {
 202                         if (buf != NULL) OPENSSL_free(buf);
 203                         OPENSSL_free(frag);
 204                         return NULL;
 205                         }
 206                 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
 207                 }
 208
 209         frag->reassembly = bitmask;
 210
 211         return frag;
 212         }
 213
 214 static void
 215 dtls1_hm_fragment_free(hm_fragment *frag)
 216         {
 217         if (frag->fragment) OPENSSL_free(frag->fragment);
 218         if (frag->reassembly) OPENSSL_free(frag->reassembly);
 219         OPENSSL_free(frag);
 220         }
 221
 222 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
 223 int dtls1_do_write(SSL *s, int type)
 224         {
 225         int ret;
 226         int curr_mtu;
 227         unsigned int len, frag_off, mac_size, blocksize;
 228
 229         /* AHA!  Figure out the MTU, and stick to the right size */
 230         if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 231                 {
 232                 s->d1->mtu =
 233                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 234
 235                 /* I've seen the kernel return bogus numbers when it doesn't know
 236                  * (initial write), so just make sure we have a reasonable number */
 237                 if (s->d1->mtu < dtls1_min_mtu())
 238                         {
 239                         s->d1->mtu = 0;
 240                         s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
 241                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
 242                                 s->d1->mtu, NULL);
 243                         }
 244                 }
 245 #if 0
 246         mtu = s->d1->mtu;
 247
 248         fprintf(stderr, "using MTU = %d\n", mtu);
 249
 250         mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 251
 252         curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
 253
 254         if ( curr_mtu > 0)
 255                 mtu = curr_mtu;
 256         else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
 257                 return ret;
 258
 259         if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
 260                 {
 261                 ret = BIO_flush(SSL_get_wbio(s));
 262                 if ( ret <= 0)
 263                         return ret;
 264                 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 265                 }
 266 #endif
 267
 268         OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu());  /* should have something reasonable now */
 269
 270         if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
 271                 OPENSSL_assert(s->init_num ==
 272                         (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
 273
 274         if (s->write_hash)
 275                 mac_size = EVP_MD_size(s->write_hash);
 276         else
 277                 mac_size = 0;
 278
 279         if (s->enc_write_ctx &&
 280                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))
 281                 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
 282         else
 283                 blocksize = 0;
 284
 285         frag_off = 0;
 286         while( s->init_num)
 287                 {
 288                 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
 289                         DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
 290
 291                 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
 292                         {
 293                         /* grr.. we could get an error if MTU picked was wrong */
 294                         ret = BIO_flush(SSL_get_wbio(s));
 295                         if ( ret <= 0)
 296                                 return ret;
 297                         curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
 298                                 mac_size - blocksize;
 299                         }
 300
 301                 if ( s->init_num > curr_mtu)
 302                         len = curr_mtu;
 303                 else
 304                         len = s->init_num;
 305
 306
 307                 /* XDTLS: this function is too long.  split out the CCS part */
 308                 if ( type == SSL3_RT_HANDSHAKE)
 309                         {
 310                         if ( s->init_off != 0)
 311                                 {
 312                                 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
 313                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
 314                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
 315
 316                                 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
 317                                 if ( len <= DTLS1_HM_HEADER_LENGTH)
 318                                         len += DTLS1_HM_HEADER_LENGTH;
 319                                 }
 320
 321                         dtls1_fix_message_header(s, frag_off,
 322                                 len - DTLS1_HM_HEADER_LENGTH);
 323
 324                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
 325
 326                         OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
 327                         }
 328
 329                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
 330                         len);
 331                 if (ret < 0)
 332                         {
 333                         /* might need to update MTU here, but we don't know
 334                          * which previous packet caused the failure -- so can't
 335                          * really retransmit anything.  continue as if everything
 336                          * is fine and wait for an alert to handle the
 337                          * retransmit
 338                          */
 339                         if ( BIO_ctrl(SSL_get_wbio(s),
 340                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
 341                                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
 342                                         BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 343                         else
 344                                 return(-1);
 345                         }
 346                 else
 347                         {
 348
 349                         /* bad if this assert fails, only part of the handshake
 350                          * message got sent.  but why would this happen? */
 351                         OPENSSL_assert(len == (unsigned int)ret);
 352
 353                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
 354                                 {
 355                                 /* should not be done for 'Hello Request's, but in that case
 356                                  * we'll ignore the result anyway */
 357                                 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
 358                                 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
 359                                 int xlen;
 360
 361                                 if (frag_off == 0 && s->client_version != DTLS1_BAD_VER)
 362                                         {
 363                                         /* reconstruct message header is if it
 364                                          * is being sent in single fragment */
 365                                         *p++ = msg_hdr->type;
 366                                         l2n3(msg_hdr->msg_len,p);
 367                                         s2n (msg_hdr->seq,p);
 368                                         l2n3(0,p);
 369                                         l2n3(msg_hdr->msg_len,p);
 370                                         p  -= DTLS1_HM_HEADER_LENGTH;
 371                                         xlen = ret;
 372                                         }
 373                                 else
 374                                         {
 375                                         p  += DTLS1_HM_HEADER_LENGTH;
 376                                         xlen = ret - DTLS1_HM_HEADER_LENGTH;
 377                                         }
 378
 379                                 ssl3_finish_mac(s, p, xlen);
 380                                 }
 381
 382                         if (ret == s->init_num)
 383                                 {
 384                                 if (s->msg_callback)
 385                                         s->msg_callback(1, s->version, type, s->init_buf->data,
 386                                                 (size_t)(s->init_off + s->init_num), s,
 387                                                 s->msg_callback_arg);
 388
 389                                 s->init_off = 0;  /* done writing this message */
 390                                 s->init_num = 0;
 391
 392                                 return(1);
 393                                 }
 394                         s->init_off+=ret;
 395                         s->init_num-=ret;
 396                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
 397                         }
 398                 }
 399         return(0);
 400         }
 401
 402
 403 /* Obtain handshake message of message type 'mt' (any if mt == -1),
 404  * maximum acceptable body length 'max'.
 405  * Read an entire handshake message.  Handshake messages arrive in
 406  * fragments.
 407  */
 408 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 409         {
 410         int i, al;
 411         struct hm_header_st *msg_hdr;
 412         unsigned char *p;
 413         unsigned long msg_len;
 414
 415         /* s3->tmp is used to store messages that are unexpected, caused
 416          * by the absence of an optional handshake message */
 417         if (s->s3->tmp.reuse_message)
 418                 {
 419                 s->s3->tmp.reuse_message=0;
 420                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
 421                         {
 422                         al=SSL_AD_UNEXPECTED_MESSAGE;
 423                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
 424                         goto f_err;
 425                         }
 426                 *ok=1;
 427                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 428                 s->init_num = (int)s->s3->tmp.message_size;
 429                 return s->init_num;
 430                 }
 431
 432         msg_hdr = &s->d1->r_msg_hdr;
 433         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 434
 435 again:
 436         i = dtls1_get_message_fragment(s, st1, stn, max, ok);
 437         if ( i == DTLS1_HM_BAD_FRAGMENT ||
 438                 i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
 439                 goto again;
 440         else if ( i <= 0 && !*ok)
 441                 return i;
 442
 443         p = (unsigned char *)s->init_buf->data;
 444         msg_len = msg_hdr->msg_len;
 445
 446         /* reconstruct message header */
 447         *(p++) = msg_hdr->type;
 448         l2n3(msg_len,p);
 449         s2n (msg_hdr->seq,p);
 450         l2n3(0,p);
 451         l2n3(msg_len,p);
 452         if (s->version != DTLS1_BAD_VER) {
 453                 p       -= DTLS1_HM_HEADER_LENGTH;
 454                 msg_len += DTLS1_HM_HEADER_LENGTH;
 455         }
 456
 457         ssl3_finish_mac(s, p, msg_len);
 458         if (s->msg_callback)
 459                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 460                         p, msg_len,
 461                         s, s->msg_callback_arg);
 462
 463         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 464
 465         /* Don't change sequence numbers while listening */
 466         if (!s->d1->listen)
 467                 s->d1->handshake_read_seq++;
 468
 469         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 470         return s->init_num;
 471
 472 f_err:
 473         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 474         *ok = 0;
 475         return -1;
 476         }
 477
 478
 479 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
 480         {
 481         size_t frag_off,frag_len,msg_len;
 482
 483         msg_len  = msg_hdr->msg_len;
 484         frag_off = msg_hdr->frag_off;
 485         frag_len = msg_hdr->frag_len;
 486
 487         /* sanity checking */
 488         if ( (frag_off+frag_len) > msg_len)
 489                 {
 490                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 491                 return SSL_AD_ILLEGAL_PARAMETER;
 492                 }
 493
 494         if ( (frag_off+frag_len) > (unsigned long)max)
 495                 {
 496                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 497                 return SSL_AD_ILLEGAL_PARAMETER;
 498                 }
 499
 500         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 501                 {
 502                 /* msg_len is limited to 2^24, but is effectively checked
 503                  * against max above */
 504                 if (!BUF_MEM_grow_clean(s->init_buf,(int)msg_len+DTLS1_HM_HEADER_LENGTH))
 505                         {
 506                         SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
 507                         return SSL_AD_INTERNAL_ERROR;
 508                         }
 509
 510                 s->s3->tmp.message_size  = msg_len;
 511                 s->d1->r_msg_hdr.msg_len = msg_len;
 512                 s->s3->tmp.message_type  = msg_hdr->type;
 513                 s->d1->r_msg_hdr.type    = msg_hdr->type;
 514                 s->d1->r_msg_hdr.seq     = msg_hdr->seq;
 515                 }
 516         else if (msg_len != s->d1->r_msg_hdr.msg_len)
 517                 {
 518                 /* They must be playing with us! BTW, failure to enforce
 519                  * upper limit would open possibility for buffer overrun. */
 520                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 521                 return SSL_AD_ILLEGAL_PARAMETER;
 522                 }
 523
 524         return 0; /* no error */
 525         }
 526
 527
 528 static int
 529 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
 530         {
 531         /* (0) check whether the desired fragment is available
 532          * if so:
 533          * (1) copy over the fragment to s->init_buf->data[]
 534          * (2) update s->init_num
 535          */
 536         pitem *item;
 537         hm_fragment *frag;
 538         int al;
 539
 540         *ok = 0;
 541         item = pqueue_peek(s->d1->buffered_messages);
 542         if ( item == NULL)
 543                 return 0;
 544
 545         frag = (hm_fragment *)item->data;
 546
 547         /* Don't return if reassembly still in progress */
 548         if (frag->reassembly != NULL)
 549                 return 0;
 550
 551         if ( s->d1->handshake_read_seq == frag->msg_header.seq)
 552                 {
 553                 unsigned long frag_len = frag->msg_header.frag_len;
 554                 pqueue_pop(s->d1->buffered_messages);
 555
 556                 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
 557
 558                 if (al==0) /* no alert */
 559                         {
 560                         unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 561                         memcpy(&p[frag->msg_header.frag_off],
 562                                 frag->fragment,frag->msg_header.frag_len);
 563                         }
 564
 565                 dtls1_hm_fragment_free(frag);
 566                 pitem_free(item);
 567
 568                 if (al==0)
 569                         {
 570                         *ok = 1;
 571                         return frag_len;
 572                         }
 573
 574                 ssl3_send_alert(s,SSL3_AL_FATAL,al);
 575                 s->init_num = 0;
 576                 *ok = 0;
 577                 return -1;
 578                 }
 579         else
 580                 return 0;
 581         }
 582
 583 /* dtls1_max_handshake_message_len returns the maximum number of bytes
 584  * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may
 585  * be greater if the maximum certificate list size requires it. */
 586 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
 587         {
 588         unsigned long max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
 589         if (max_len < (unsigned long)s->max_cert_list)
 590                 return s->max_cert_list;
 591         return max_len;
 592         }
 593
 594 static int
 595 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 596         {
 597         hm_fragment *frag = NULL;
 598         pitem *item = NULL;
 599         int i = -1, is_complete;
 600         PQ_64BIT seq64;
 601         unsigned long frag_len = msg_hdr->frag_len;
 602
 603         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len ||
 604             msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
 605                 goto err;
 606
 607         if (frag_len == 0)
 608                 return DTLS1_HM_FRAGMENT_RETRY;
 609
 610         /* Try to find item in queue */
 611         pq_64bit_init(&seq64);
 612         pq_64bit_assign_word(&seq64, msg_hdr->seq);
 613         item = pqueue_find(s->d1->buffered_messages, seq64);
 614         pq_64bit_free(&seq64);
 615
 616         if (item == NULL)
 617                 {
 618                 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
 619                 if ( frag == NULL)
 620                         goto err;
 621                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 622                 frag->msg_header.frag_len = frag->msg_header.msg_len;
 623                 frag->msg_header.frag_off = 0;
 624                 }
 625         else
 626                 {
 627                 frag = (hm_fragment*) item->data;
 628                 if (frag->msg_header.msg_len != msg_hdr->msg_len)
 629                         {
 630                         item = NULL;
 631                         frag = NULL;
 632                         goto err;
 633                         }
 634                 }
 635
 636
 637         /* If message is already reassembled, this must be a
 638          * retransmit and can be dropped. In this case item != NULL and so frag
 639          * does not need to be freed.
 640          */
 641         if (frag->reassembly == NULL)
 642                 {
 643                 unsigned char devnull [256];
 644
 645                 while (frag_len)
 646                         {
 647                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 648                                 devnull,
 649                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 650                         if (i<=0) goto err;
 651                         frag_len -= i;
 652                         }
 653                 return DTLS1_HM_FRAGMENT_RETRY;
 654                 }
 655
 656         /* read the body of the fragment (header has already been read */
 657         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 658                 frag->fragment + msg_hdr->frag_off,frag_len,0);
 659         if ((unsigned long)i!=frag_len)
 660                 i=-1;
 661         if (i<=0)
 662                 goto err;
 663
 664         RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
 665                             (long)(msg_hdr->frag_off + frag_len));
 666
 667         RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
 668                                    is_complete);
 669
 670         if (is_complete)
 671                 {
 672                 OPENSSL_free(frag->reassembly);
 673                 frag->reassembly = NULL;
 674                 }
 675
 676         if (item == NULL)
 677                 {
 678                 pq_64bit_init(&seq64);
 679                 pq_64bit_assign_word(&seq64, msg_hdr->seq);
 680                 item = pitem_new(seq64, frag);
 681                 pq_64bit_free(&seq64);
 682
 683                 if (item == NULL)
 684                         {
 685                         goto err;
 686                         i = -1;
 687                         }
 688
 689                 item = pqueue_insert(s->d1->buffered_messages, item);
 690                 /* pqueue_insert fails iff a duplicate item is inserted.
 691                  * However, |item| cannot be a duplicate. If it were,
 692                  * |pqueue_find|, above, would have returned it and control
 693                  * would never have reached this branch. */
 694                 OPENSSL_assert(item != NULL);
 695                 }
 696
 697         return DTLS1_HM_FRAGMENT_RETRY;
 698
 699 err:
 700         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 701         *ok = 0;
 702         return i;
 703         }
 704
 705
 706 static int
 707 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 708 {
 709         int i=-1;
 710         hm_fragment *frag = NULL;
 711         pitem *item = NULL;
 712         PQ_64BIT seq64;
 713         unsigned long frag_len = msg_hdr->frag_len;
 714
 715         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 716                 goto err;
 717
 718         /* Try to find item in queue, to prevent duplicate entries */
 719         pq_64bit_init(&seq64);
 720         pq_64bit_assign_word(&seq64, msg_hdr->seq);
 721         item = pqueue_find(s->d1->buffered_messages, seq64);
 722         pq_64bit_free(&seq64);
 723
 724         /* If we already have an entry and this one is a fragment,
 725          * don't discard it and rather try to reassemble it.
 726          */
 727         if (item != NULL && frag_len != msg_hdr->msg_len)
 728                 item = NULL;
 729
 730         /* Discard the message if sequence number was already there, is
 731          * too far in the future, already in the queue or if we received
 732          * a FINISHED before the SERVER_HELLO, which then must be a stale
 733          * retransmit.
 734          */
 735         if (msg_hdr->seq <= s->d1->handshake_read_seq ||
 736                 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
 737                 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
 738                 {
 739                 unsigned char devnull [256];
 740
 741                 while (frag_len)
 742                         {
 743                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 744                                 devnull,
 745                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 746                         if (i<=0) goto err;
 747                         frag_len -= i;
 748                         }
 749                 }
 750         else
 751                 {
 752                 if (frag_len != msg_hdr->msg_len)
 753                         return dtls1_reassemble_fragment(s, msg_hdr, ok);
 754
 755                 if (frag_len > dtls1_max_handshake_message_len(s))
 756                         goto err;
 757
 758                 frag = dtls1_hm_fragment_new(frag_len, 0);
 759                 if ( frag == NULL)
 760                         goto err;
 761
 762                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 763
 764                 if (frag_len)
 765                         {
 766                         /* read the body of the fragment (header has already been read) */
 767                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 768                                 frag->fragment,frag_len,0);
 769                         if ((unsigned long)i!=frag_len)
 770                                 i = -1;
 771                         if (i<=0)
 772                                 goto err;
 773                         }
 774
 775                 pq_64bit_init(&seq64);
 776                 pq_64bit_assign_word(&seq64, msg_hdr->seq);
 777
 778                 item = pitem_new(seq64, frag);
 779                 pq_64bit_free(&seq64);
 780                 if ( item == NULL)
 781                         goto err;
 782
 783                 item = pqueue_insert(s->d1->buffered_messages, item);
 784                 /* pqueue_insert fails iff a duplicate item is inserted.
 785                  * However, |item| cannot be a duplicate. If it were,
 786                  * |pqueue_find|, above, would have returned it. Then, either
 787                  * |frag_len| != |msg_hdr->msg_len| in which case |item| is set
 788                  * to NULL and it will have been processed with
 789                  * |dtls1_reassemble_fragment|, above, or the record will have
 790                  * been discarded. */
 791                 OPENSSL_assert(item != NULL);
 792                 }
 793
 794         return DTLS1_HM_FRAGMENT_RETRY;
 795
 796 err:
 797         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 798         *ok = 0;
 799         return i;
 800         }
 801
 802
 803 static long
 804 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 805         {
 806         unsigned char wire[DTLS1_HM_HEADER_LENGTH];
 807         unsigned long len, frag_off, frag_len;
 808         int i,al;
 809         struct hm_header_st msg_hdr;
 810
 811         redo:
 812         /* see if we have the required fragment already */
 813         if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
 814                 {
 815                 if (*ok)        s->init_num = frag_len;
 816                 return frag_len;
 817                 }
 818
 819         /* read handshake message header */
 820         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
 821                 DTLS1_HM_HEADER_LENGTH, 0);
 822         if (i <= 0)     /* nbio, or an error */
 823                 {
 824                 s->rwstate=SSL_READING;
 825                 *ok = 0;
 826                 return i;
 827                 }
 828         /* Handshake fails if message header is incomplete */
 829         if (i != DTLS1_HM_HEADER_LENGTH)
 830                 {
 831                 al=SSL_AD_UNEXPECTED_MESSAGE;
 832                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 833                 goto f_err;
 834                 }
 835
 836         /* parse the message fragment header */
 837         dtls1_get_message_header(wire, &msg_hdr);
 838
 839         /*
 840          * if this is a future (or stale) message it gets buffered
 841          * (or dropped)--no further processing at this time
 842          * While listening, we accept seq 1 (ClientHello with cookie)
 843          * although we're still expecting seq 0 (ClientHello)
 844          */
 845         if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
 846                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 847
 848         len = msg_hdr.msg_len;
 849         frag_off = msg_hdr.frag_off;
 850         frag_len = msg_hdr.frag_len;
 851
 852         if (frag_len && frag_len < len)
 853                 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
 854
 855         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 856                 wire[0] == SSL3_MT_HELLO_REQUEST)
 857                 {
 858                 /* The server may always send 'Hello Request' messages --
 859                  * we are doing a handshake anyway now, so ignore them
 860                  * if their format is correct. Does not count for
 861                  * 'Finished' MAC. */
 862                 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
 863                         {
 864                         if (s->msg_callback)
 865                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 866                                         wire, DTLS1_HM_HEADER_LENGTH, s,
 867                                         s->msg_callback_arg);
 868
 869                         s->init_num = 0;
 870                         goto redo;
 871                         }
 872                 else /* Incorrectly formated Hello request */
 873                         {
 874                         al=SSL_AD_UNEXPECTED_MESSAGE;
 875                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 876                         goto f_err;
 877                         }
 878                 }
 879
 880         if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
 881                 goto f_err;
 882
 883         /* XDTLS:  ressurect this when restart is in place */
 884         s->state=stn;
 885
 886         if ( frag_len > 0)
 887                 {
 888                 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 889
 890                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 891                         &p[frag_off],frag_len,0);
 892                 /* XDTLS:  fix this--message fragments cannot span multiple packets */
 893                 if (i <= 0)
 894                         {
 895                         s->rwstate=SSL_READING;
 896                         *ok = 0;
 897                         return i;
 898                         }
 899                 }
 900         else
 901                 i = 0;
 902
 903         /* XDTLS:  an incorrectly formatted fragment should cause the
 904          * handshake to fail */
 905         if (i != (int)frag_len)
 906                 {
 907                 al=SSL3_AD_ILLEGAL_PARAMETER;
 908                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
 909                 goto f_err;
 910                 }
 911
 912         *ok = 1;
 913
 914         /* Note that s->init_num is *not* used as current offset in
 915          * s->init_buf->data, but as a counter summing up fragments'
 916          * lengths: as soon as they sum up to handshake packet
 917          * length, we assume we have got all the fragments. */
 918         s->init_num = frag_len;
 919         return frag_len;
 920
 921 f_err:
 922         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 923         s->init_num = 0;
 924
 925         *ok=0;
 926         return(-1);
 927         }
 928
 929 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
 930         {
 931         unsigned char *p,*d;
 932         int i;
 933         unsigned long l;
 934
 935         if (s->state == a)
 936                 {
 937                 d=(unsigned char *)s->init_buf->data;
 938                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
 939
 940                 i=s->method->ssl3_enc->final_finish_mac(s,
 941                         &(s->s3->finish_dgst1),
 942                         &(s->s3->finish_dgst2),
 943                         sender,slen,s->s3->tmp.finish_md);
 944                 s->s3->tmp.finish_md_len = i;
 945                 memcpy(p, s->s3->tmp.finish_md, i);
 946                 p+=i;
 947                 l=i;
 948
 949         /* Copy the finished so we can use it for
 950          * renegotiation checks
 951          */
 952         if(s->type == SSL_ST_CONNECT)
 953                 {
 954                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 955                 memcpy(s->s3->previous_client_finished,
 956                        s->s3->tmp.finish_md, i);
 957                 s->s3->previous_client_finished_len=i;
 958                 }
 959         else
 960                 {
 961                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 962                 memcpy(s->s3->previous_server_finished,
 963                        s->s3->tmp.finish_md, i);
 964                 s->s3->previous_server_finished_len=i;
 965                 }
 966
 967 #ifdef OPENSSL_SYS_WIN16
 968                 /* MSVC 1.5 does not clear the top bytes of the word unless
 969                  * I do this.
 970                  */
 971                 l&=0xffff;
 972 #endif
 973
 974                 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
 975                 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
 976                 s->init_off=0;
 977
 978                 /* buffer the message to handle re-xmits */
 979                 dtls1_buffer_message(s, 0);
 980
 981                 s->state=b;
 982                 }
 983
 984         /* SSL3_ST_SEND_xxxxxx_HELLO_B */
 985         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 986         }
 987
 988 /* for these 2 messages, we need to
 989  * ssl->enc_read_ctx                    re-init
 990  * ssl->s3->read_sequence               zero
 991  * ssl->s3->read_mac_secret             re-init
 992  * ssl->session->read_sym_enc           assign
 993  * ssl->session->read_compression       assign
 994  * ssl->session->read_hash              assign
 995  */
 996 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
 997         {
 998         unsigned char *p;
 999
1000         if (s->state == a)
1001                 {
1002                 p=(unsigned char *)s->init_buf->data;
1003                 *p++=SSL3_MT_CCS;
1004                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1005                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
1006
1007                 if (s->client_version == DTLS1_BAD_VER)
1008                         {
1009                         s->d1->next_handshake_write_seq++;
1010                         s2n(s->d1->handshake_write_seq,p);
1011                         s->init_num+=2;
1012                         }
1013
1014                 s->init_off=0;
1015
1016                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1017                         s->d1->handshake_write_seq, 0, 0);
1018
1019                 /* buffer the message to handle re-xmits */
1020                 dtls1_buffer_message(s, 1);
1021
1022                 s->state=b;
1023                 }
1024
1025         /* SSL3_ST_CW_CHANGE_B */
1026         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
1027         }
1028
1029 static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
1030         {
1031                 int n;
1032                 unsigned char *p;
1033
1034                 n=i2d_X509(x,NULL);
1035                 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
1036                         {
1037                         SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
1038                         return 0;
1039                         }
1040                 p=(unsigned char *)&(buf->data[*l]);
1041                 l2n3(n,p);
1042                 i2d_X509(x,&p);
1043                 *l+=n+3;
1044
1045                 return 1;
1046         }
1047 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
1048         {
1049         unsigned char *p;
1050         int i;
1051         unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
1052         BUF_MEM *buf;
1053
1054         /* TLSv1 sends a chain with nothing in it, instead of an alert */
1055         buf=s->init_buf;
1056         if (!BUF_MEM_grow_clean(buf,10))
1057                 {
1058                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
1059                 return(0);
1060                 }
1061         if (x != NULL)
1062                 {
1063                 X509_STORE_CTX xs_ctx;
1064
1065                 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
1066                         {
1067                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
1068                         return(0);
1069                         }
1070
1071                 X509_verify_cert(&xs_ctx);
1072                 /* Don't leave errors in the queue */
1073                 ERR_clear_error();
1074                 for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
1075                         {
1076                         x = sk_X509_value(xs_ctx.chain, i);
1077
1078                         if (!dtls1_add_cert_to_buf(buf, &l, x))
1079                                 {
1080                                 X509_STORE_CTX_cleanup(&xs_ctx);
1081                                 return 0;
1082                                 }
1083                         }
1084                 X509_STORE_CTX_cleanup(&xs_ctx);
1085                 }
1086         /* Thawte special :-) */
1087         for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
1088                 {
1089                 x=sk_X509_value(s->ctx->extra_certs,i);
1090                 if (!dtls1_add_cert_to_buf(buf, &l, x))
1091                         return 0;
1092                 }
1093
1094         l-= (3 + DTLS1_HM_HEADER_LENGTH);
1095
1096         p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1097         l2n3(l,p);
1098         l+=3;
1099         p=(unsigned char *)&(buf->data[0]);
1100         p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1101
1102         l+=DTLS1_HM_HEADER_LENGTH;
1103         return(l);
1104         }
1105
1106 int dtls1_read_failed(SSL *s, int code)
1107         {
1108         if ( code > 0)
1109                 {
1110                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1111                 return 1;
1112                 }
1113
1114         if (!dtls1_is_timer_expired(s))
1115                 {
1116                 /* not a timeout, none of our business,
1117                    let higher layers handle this.  in fact it's probably an error */
1118                 return code;
1119                 }
1120
1121         if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
1122                 {
1123                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1124                 return code;
1125                 }
1126
1127 #if 0 /* for now, each alert contains only one record number */
1128         item = pqueue_peek(state->rcvd_records);
1129         if ( item )
1130                 {
1131                 /* send an alert immediately for all the missing records */
1132                 }
1133         else
1134 #endif
1135
1136 #if 0  /* no more alert sending, just retransmit the last set of messages */
1137         if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1138                 ssl3_send_alert(s,SSL3_AL_WARNING,
1139                         DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1140 #endif
1141
1142         return dtls1_handle_timeout(s);
1143         }
1144
1145 int
1146 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1147         {
1148         /* The index of the retransmission queue actually is the message sequence number,
1149          * since the queue only contains messages of a single handshake. However, the
1150          * ChangeCipherSpec has no message sequence number and so using only the sequence
1151          * will result in the CCS and Finished having the same index. To prevent this,
1152          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1153          * This does not only differ CSS and Finished, it also maintains the order of the
1154          * index (important for priority queues) and fits in the unsigned short variable.
1155          */
1156         return seq * 2 - is_ccs;
1157         }
1158
1159 int
1160 dtls1_retransmit_buffered_messages(SSL *s)
1161         {
1162         pqueue sent = s->d1->sent_messages;
1163         piterator iter;
1164         pitem *item;
1165         hm_fragment *frag;
1166         int found = 0;
1167
1168         iter = pqueue_iterator(sent);
1169
1170         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1171                 {
1172                 frag = (hm_fragment *)item->data;
1173                         if ( dtls1_retransmit_message(s,
1174                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1175                                 0, &found) <= 0 && found)
1176                         {
1177                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1178                         return -1;
1179                         }
1180                 }
1181
1182         return 1;
1183         }
1184
1185 int
1186 dtls1_buffer_message(SSL *s, int is_ccs)
1187         {
1188         pitem *item;
1189         hm_fragment *frag;
1190         PQ_64BIT seq64;
1191
1192         /* this function is called immediately after a message has
1193          * been serialized */
1194         OPENSSL_assert(s->init_off == 0);
1195
1196         frag = dtls1_hm_fragment_new(s->init_num, 0);
1197
1198         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1199
1200         if ( is_ccs)
1201                 {
1202                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1203                         DTLS1_CCS_HEADER_LENGTH <= (unsigned int)s->init_num);
1204                 }
1205         else
1206                 {
1207                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1208                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1209                 }
1210
1211         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1212         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1213         frag->msg_header.type = s->d1->w_msg_hdr.type;
1214         frag->msg_header.frag_off = 0;
1215         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1216         frag->msg_header.is_ccs = is_ccs;
1217
1218         /* save current state*/
1219         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1220         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1221         frag->msg_header.saved_retransmit_state.compress = s->compress;
1222         frag->msg_header.saved_retransmit_state.session = s->session;
1223         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1224
1225         pq_64bit_init(&seq64);
1226
1227         pq_64bit_assign_word(&seq64,
1228                                                  dtls1_get_queue_priority(frag->msg_header.seq,
1229                                                                                                   frag->msg_header.is_ccs));
1230
1231         item = pitem_new(seq64, frag);
1232         pq_64bit_free(&seq64);
1233         if ( item == NULL)
1234                 {
1235                 dtls1_hm_fragment_free(frag);
1236                 return 0;
1237                 }
1238
1239 #if 0
1240         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1241         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1242         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1243 #endif
1244
1245         pqueue_insert(s->d1->sent_messages, item);
1246         return 1;
1247         }
1248
1249 int
1250 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1251         int *found)
1252         {
1253         int ret;
1254         /* XDTLS: for now assuming that read/writes are blocking */
1255         pitem *item;
1256         hm_fragment *frag ;
1257         unsigned long header_length;
1258         PQ_64BIT seq64;
1259         struct dtls1_retransmit_state saved_state;
1260         unsigned char save_write_sequence[8];
1261
1262         /*
1263           OPENSSL_assert(s->init_num == 0);
1264           OPENSSL_assert(s->init_off == 0);
1265          */
1266
1267         /* XDTLS:  the requested message ought to be found, otherwise error */
1268         pq_64bit_init(&seq64);
1269         pq_64bit_assign_word(&seq64, seq);
1270
1271         item = pqueue_find(s->d1->sent_messages, seq64);
1272         pq_64bit_free(&seq64);
1273         if ( item == NULL)
1274                 {
1275                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1276                 *found = 0;
1277                 return 0;
1278                 }
1279
1280         *found = 1;
1281         frag = (hm_fragment *)item->data;
1282
1283         if ( frag->msg_header.is_ccs)
1284                 header_length = DTLS1_CCS_HEADER_LENGTH;
1285         else
1286                 header_length = DTLS1_HM_HEADER_LENGTH;
1287
1288         memcpy(s->init_buf->data, frag->fragment,
1289                 frag->msg_header.msg_len + header_length);
1290                 s->init_num = frag->msg_header.msg_len + header_length;
1291
1292         dtls1_set_message_header_int(s, frag->msg_header.type,
1293                 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1294                 frag->msg_header.frag_len);
1295
1296         /* save current state */
1297         saved_state.enc_write_ctx = s->enc_write_ctx;
1298         saved_state.write_hash = s->write_hash;
1299         saved_state.compress = s->compress;
1300         saved_state.session = s->session;
1301         saved_state.epoch = s->d1->w_epoch;
1302         saved_state.epoch = s->d1->w_epoch;
1303
1304         s->d1->retransmitting = 1;
1305
1306         /* restore state in which the message was originally sent */
1307         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1308         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1309         s->compress = frag->msg_header.saved_retransmit_state.compress;
1310         s->session = frag->msg_header.saved_retransmit_state.session;
1311         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1312
1313         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1314         {
1315                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1316                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1317         }
1318
1319         ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1320                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1321
1322         /* restore current state */
1323         s->enc_write_ctx = saved_state.enc_write_ctx;
1324         s->write_hash = saved_state.write_hash;
1325         s->compress = saved_state.compress;
1326         s->session = saved_state.session;
1327         s->d1->w_epoch = saved_state.epoch;
1328
1329         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1330         {
1331                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1332                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1333         }
1334
1335         s->d1->retransmitting = 0;
1336
1337         (void)BIO_flush(SSL_get_wbio(s));
1338         return ret;
1339         }
1340
1341 /* call this function when the buffered messages are no longer needed */
1342 void
1343 dtls1_clear_record_buffer(SSL *s)
1344         {
1345         pitem *item;
1346
1347         for(item = pqueue_pop(s->d1->sent_messages);
1348                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1349                 {
1350                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1351                 pitem_free(item);
1352                 }
1353         }
1354
1355
1356 unsigned char *
1357 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1358                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1359         {
1360         /* Don't change sequence numbers while listening */
1361         if (frag_off == 0 && !s->d1->listen)
1362                 {
1363                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1364                 s->d1->next_handshake_write_seq++;
1365                 }
1366
1367         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1368                 frag_off, frag_len);
1369
1370         return p += DTLS1_HM_HEADER_LENGTH;
1371         }
1372
1373
1374 /* don't actually do the writing, wait till the MTU has been retrieved */
1375 static void
1376 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1377                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1378                             unsigned long frag_len)
1379         {
1380         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1381
1382         msg_hdr->type = mt;
1383         msg_hdr->msg_len = len;
1384         msg_hdr->seq = seq_num;
1385         msg_hdr->frag_off = frag_off;
1386         msg_hdr->frag_len = frag_len;
1387         }
1388
1389 static void
1390 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1391                         unsigned long frag_len)
1392         {
1393         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1394
1395         msg_hdr->frag_off = frag_off;
1396         msg_hdr->frag_len = frag_len;
1397         }
1398
1399 static unsigned char *
1400 dtls1_write_message_header(SSL *s, unsigned char *p)
1401         {
1402         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1403
1404         *p++ = msg_hdr->type;
1405         l2n3(msg_hdr->msg_len, p);
1406
1407         s2n(msg_hdr->seq, p);
1408         l2n3(msg_hdr->frag_off, p);
1409         l2n3(msg_hdr->frag_len, p);
1410
1411         return p;
1412         }
1413
1414 unsigned int
1415 dtls1_min_mtu(void)
1416         {
1417         return (g_probable_mtu[(sizeof(g_probable_mtu) /
1418                 sizeof(g_probable_mtu[0])) - 1]);
1419         }
1420
1421 static unsigned int
1422 dtls1_guess_mtu(unsigned int curr_mtu)
1423         {
1424         size_t i;
1425
1426         if ( curr_mtu == 0 )
1427                 return g_probable_mtu[0] ;
1428
1429         for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1430                 if ( curr_mtu > g_probable_mtu[i])
1431                         return g_probable_mtu[i];
1432
1433         return curr_mtu;
1434         }
1435
1436 void
1437 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1438         {
1439         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1440         msg_hdr->type = *(data++);
1441         n2l3(data, msg_hdr->msg_len);
1442
1443         n2s(data, msg_hdr->seq);
1444         n2l3(data, msg_hdr->frag_off);
1445         n2l3(data, msg_hdr->frag_len);
1446         }
1447
1448 void
1449 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1450         {
1451         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1452
1453         ccs_hdr->type = *(data++);
1454         }