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[]   = {0x00, 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_min_mtu(void);
 162 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
 163 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
 164         unsigned long frag_len);
 165 static unsigned char *dtls1_write_message_header(SSL *s,
 166         unsigned char *p);
 167 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
 168         unsigned long len, unsigned short seq_num, unsigned long frag_off,
 169         unsigned long frag_len);
 170 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
 171         long max, int *ok);
 172
 173 static hm_fragment *
 174 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
 175         {
 176         hm_fragment *frag = NULL;
 177         unsigned char *buf = NULL;
 178         unsigned char *bitmask = NULL;
 179
 180         frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
 181         if ( frag == NULL)
 182                 return NULL;
 183
 184         if (frag_len)
 185                 {
 186                 buf = (unsigned char *)OPENSSL_malloc(frag_len);
 187                 if ( buf == NULL)
 188                         {
 189                         OPENSSL_free(frag);
 190                         return NULL;
 191                         }
 192                 }
 193
 194         /* zero length fragment gets zero frag->fragment */
 195         frag->fragment = buf;
 196
 197         /* Initialize reassembly bitmask if necessary */
 198         if (reassembly)
 199                 {
 200                 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
 201                 if (bitmask == NULL)
 202                         {
 203                         if (buf != NULL) OPENSSL_free(buf);
 204                         OPENSSL_free(frag);
 205                         return NULL;
 206                         }
 207                 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
 208                 }
 209
 210         frag->reassembly = bitmask;
 211
 212         return frag;
 213         }
 214
 215 static void
 216 dtls1_hm_fragment_free(hm_fragment *frag)
 217         {
 218         if (frag->fragment) OPENSSL_free(frag->fragment);
 219         if (frag->reassembly) OPENSSL_free(frag->reassembly);
 220         OPENSSL_free(frag);
 221         }
 222
 223 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
 224 int dtls1_do_write(SSL *s, int type)
 225         {
 226         int ret;
 227         int curr_mtu;
 228         unsigned int len, frag_off, mac_size, blocksize;
 229
 230         /* AHA!  Figure out the MTU, and stick to the right size */
 231         if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 232                 {
 233                 s->d1->mtu =
 234                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 235
 236                 /* I've seen the kernel return bogus numbers when it doesn't know
 237                  * (initial write), so just make sure we have a reasonable number */
 238                 if ( s->d1->mtu < dtls1_min_mtu())
 239                         {
 240                         s->d1->mtu = 0;
 241                         s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
 242                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
 243                                 s->d1->mtu, NULL);
 244                         }
 245                 }
 246 #if 0
 247         mtu = s->d1->mtu;
 248
 249         fprintf(stderr, "using MTU = %d\n", mtu);
 250
 251         mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 252
 253         curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
 254
 255         if ( curr_mtu > 0)
 256                 mtu = curr_mtu;
 257         else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
 258                 return ret;
 259
 260         if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
 261                 {
 262                 ret = BIO_flush(SSL_get_wbio(s));
 263                 if ( ret <= 0)
 264                         return ret;
 265                 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 266                 }
 267
 268         OPENSSL_assert(mtu > 0);  /* should have something reasonable now */
 269
 270 #endif
 271
 272         if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
 273                 OPENSSL_assert(s->init_num ==
 274                         (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
 275
 276         if (s->write_hash)
 277                 mac_size = EVP_MD_size(s->write_hash);
 278         else
 279                 mac_size = 0;
 280
 281         if (s->enc_write_ctx &&
 282                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))
 283                 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
 284         else
 285                 blocksize = 0;
 286
 287         frag_off = 0;
 288         while( s->init_num)
 289                 {
 290                 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
 291                         DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
 292
 293                 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
 294                         {
 295                         /* grr.. we could get an error if MTU picked was wrong */
 296                         ret = BIO_flush(SSL_get_wbio(s));
 297                         if ( ret <= 0)
 298                                 return ret;
 299                         curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
 300                                 mac_size - blocksize;
 301                         }
 302
 303                 if ( s->init_num > curr_mtu)
 304                         len = curr_mtu;
 305                 else
 306                         len = s->init_num;
 307
 308
 309                 /* XDTLS: this function is too long.  split out the CCS part */
 310                 if ( type == SSL3_RT_HANDSHAKE)
 311                         {
 312                         if ( s->init_off != 0)
 313                                 {
 314                                 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
 315                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
 316                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
 317
 318                                 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
 319                                 if ( len <= DTLS1_HM_HEADER_LENGTH)
 320                                         len += DTLS1_HM_HEADER_LENGTH;
 321                                 }
 322
 323                         dtls1_fix_message_header(s, frag_off,
 324                                 len - DTLS1_HM_HEADER_LENGTH);
 325
 326                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
 327
 328                         OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
 329                         }
 330
 331                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
 332                         len);
 333                 if (ret < 0)
 334                         {
 335                         /* might need to update MTU here, but we don't know
 336                          * which previous packet caused the failure -- so can't
 337                          * really retransmit anything.  continue as if everything
 338                          * is fine and wait for an alert to handle the
 339                          * retransmit
 340                          */
 341                         if ( BIO_ctrl(SSL_get_wbio(s),
 342                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
 343                                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
 344                                         BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 345                         else
 346                                 return(-1);
 347                         }
 348                 else
 349                         {
 350
 351                         /* bad if this assert fails, only part of the handshake
 352                          * message got sent.  but why would this happen? */
 353                         OPENSSL_assert(len == (unsigned int)ret);
 354
 355                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
 356                                 {
 357                                 /* should not be done for 'Hello Request's, but in that case
 358                                  * we'll ignore the result anyway */
 359                                 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
 360                                 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
 361                                 int xlen;
 362
 363                                 if (frag_off == 0 && s->client_version != DTLS1_BAD_VER)
 364                                         {
 365                                         /* reconstruct message header is if it
 366                                          * is being sent in single fragment */
 367                                         *p++ = msg_hdr->type;
 368                                         l2n3(msg_hdr->msg_len,p);
 369                                         s2n (msg_hdr->seq,p);
 370                                         l2n3(0,p);
 371                                         l2n3(msg_hdr->msg_len,p);
 372                                         p  -= DTLS1_HM_HEADER_LENGTH;
 373                                         xlen = ret;
 374                                         }
 375                                 else
 376                                         {
 377                                         p  += DTLS1_HM_HEADER_LENGTH;
 378                                         xlen = ret - DTLS1_HM_HEADER_LENGTH;
 379                                         }
 380
 381                                 ssl3_finish_mac(s, p, xlen);
 382                                 }
 383
 384                         if (ret == s->init_num)
 385                                 {
 386                                 if (s->msg_callback)
 387                                         s->msg_callback(1, s->version, type, s->init_buf->data,
 388                                                 (size_t)(s->init_off + s->init_num), s,
 389                                                 s->msg_callback_arg);
 390
 391                                 s->init_off = 0;  /* done writing this message */
 392                                 s->init_num = 0;
 393
 394                                 return(1);
 395                                 }
 396                         s->init_off+=ret;
 397                         s->init_num-=ret;
 398                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
 399                         }
 400                 }
 401         return(0);
 402         }
 403
 404
 405 /* Obtain handshake message of message type 'mt' (any if mt == -1),
 406  * maximum acceptable body length 'max'.
 407  * Read an entire handshake message.  Handshake messages arrive in
 408  * fragments.
 409  */
 410 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 411         {
 412         int i, al;
 413         struct hm_header_st *msg_hdr;
 414         unsigned char *p;
 415         unsigned long msg_len;
 416
 417         /* s3->tmp is used to store messages that are unexpected, caused
 418          * by the absence of an optional handshake message */
 419         if (s->s3->tmp.reuse_message)
 420                 {
 421                 s->s3->tmp.reuse_message=0;
 422                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
 423                         {
 424                         al=SSL_AD_UNEXPECTED_MESSAGE;
 425                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
 426                         goto f_err;
 427                         }
 428                 *ok=1;
 429                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 430                 s->init_num = (int)s->s3->tmp.message_size;
 431                 return s->init_num;
 432                 }
 433
 434         msg_hdr = &s->d1->r_msg_hdr;
 435         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 436
 437 again:
 438         i = dtls1_get_message_fragment(s, st1, stn, max, ok);
 439         if ( i == DTLS1_HM_BAD_FRAGMENT ||
 440                 i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
 441                 goto again;
 442         else if ( i <= 0 && !*ok)
 443                 return i;
 444
 445         p = (unsigned char *)s->init_buf->data;
 446         msg_len = msg_hdr->msg_len;
 447
 448         /* reconstruct message header */
 449         *(p++) = msg_hdr->type;
 450         l2n3(msg_len,p);
 451         s2n (msg_hdr->seq,p);
 452         l2n3(0,p);
 453         l2n3(msg_len,p);
 454         if (s->version != DTLS1_BAD_VER) {
 455                 p       -= DTLS1_HM_HEADER_LENGTH;
 456                 msg_len += DTLS1_HM_HEADER_LENGTH;
 457         }
 458
 459         ssl3_finish_mac(s, p, msg_len);
 460         if (s->msg_callback)
 461                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 462                         p, msg_len,
 463                         s, s->msg_callback_arg);
 464
 465         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 466
 467         s->d1->handshake_read_seq++;
 468         /* we just read a handshake message from the other side:
 469          * this means that we don't need to retransmit of the
 470          * buffered messages.
 471          * XDTLS: may be able clear out this
 472          * buffer a little sooner (i.e if an out-of-order
 473          * handshake message/record is received at the record
 474          * layer.
 475          * XDTLS: exception is that the server needs to
 476          * know that change cipher spec and finished messages
 477          * have been received by the client before clearing this
 478          * buffer.  this can simply be done by waiting for the
 479          * first data  segment, but is there a better way?  */
 480         dtls1_clear_record_buffer(s);
 481
 482         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 483         return s->init_num;
 484
 485 f_err:
 486         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 487         *ok = 0;
 488         return -1;
 489         }
 490
 491
 492 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
 493         {
 494         size_t frag_off,frag_len,msg_len;
 495
 496         msg_len  = msg_hdr->msg_len;
 497         frag_off = msg_hdr->frag_off;
 498         frag_len = msg_hdr->frag_len;
 499
 500         /* sanity checking */
 501         if ( (frag_off+frag_len) > msg_len)
 502                 {
 503                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 504                 return SSL_AD_ILLEGAL_PARAMETER;
 505                 }
 506
 507         if ( (frag_off+frag_len) > (unsigned long)max)
 508                 {
 509                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 510                 return SSL_AD_ILLEGAL_PARAMETER;
 511                 }
 512
 513         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 514                 {
 515                 /* msg_len is limited to 2^24, but is effectively checked
 516                  * against max above */
 517                 if (!BUF_MEM_grow_clean(s->init_buf,(int)msg_len+DTLS1_HM_HEADER_LENGTH))
 518                         {
 519                         SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
 520                         return SSL_AD_INTERNAL_ERROR;
 521                         }
 522
 523                 s->s3->tmp.message_size  = msg_len;
 524                 s->d1->r_msg_hdr.msg_len = msg_len;
 525                 s->s3->tmp.message_type  = msg_hdr->type;
 526                 s->d1->r_msg_hdr.type    = msg_hdr->type;
 527                 s->d1->r_msg_hdr.seq     = msg_hdr->seq;
 528                 }
 529         else if (msg_len != s->d1->r_msg_hdr.msg_len)
 530                 {
 531                 /* They must be playing with us! BTW, failure to enforce
 532                  * upper limit would open possibility for buffer overrun. */
 533                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 534                 return SSL_AD_ILLEGAL_PARAMETER;
 535                 }
 536
 537         return 0; /* no error */
 538         }
 539
 540
 541 static int
 542 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
 543         {
 544         /* (0) check whether the desired fragment is available
 545          * if so:
 546          * (1) copy over the fragment to s->init_buf->data[]
 547          * (2) update s->init_num
 548          */
 549         pitem *item;
 550         hm_fragment *frag;
 551         int al;
 552
 553         *ok = 0;
 554         item = pqueue_peek(s->d1->buffered_messages);
 555         if ( item == NULL)
 556                 return 0;
 557
 558         frag = (hm_fragment *)item->data;
 559
 560         /* Don't return if reassembly still in progress */
 561         if (frag->reassembly != NULL)
 562                 return 0;
 563
 564         if ( s->d1->handshake_read_seq == frag->msg_header.seq)
 565                 {
 566                 unsigned long frag_len = frag->msg_header.frag_len;
 567                 pqueue_pop(s->d1->buffered_messages);
 568
 569                 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
 570
 571                 if (al==0) /* no alert */
 572                         {
 573                         unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 574                         memcpy(&p[frag->msg_header.frag_off],
 575                                 frag->fragment,frag->msg_header.frag_len);
 576                         }
 577
 578                 dtls1_hm_fragment_free(frag);
 579                 pitem_free(item);
 580
 581                 if (al==0)
 582                         {
 583                         *ok = 1;
 584                         return frag_len;
 585                         }
 586
 587                 ssl3_send_alert(s,SSL3_AL_FATAL,al);
 588                 s->init_num = 0;
 589                 *ok = 0;
 590                 return -1;
 591                 }
 592         else
 593                 return 0;
 594         }
 595
 596
 597 static int
 598 dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
 599         {
 600         hm_fragment *frag = NULL;
 601         pitem *item = NULL;
 602         int i = -1, is_complete;
 603         PQ_64BIT seq64;
 604         unsigned long frag_len = msg_hdr->frag_len, max_len;
 605
 606         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 607                 goto err;
 608
 609         /* Determine maximum allowed message size. Depends on (user set)
 610          * maximum certificate length, but 16k is minimum.
 611          */
 612         if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list)
 613                 max_len = s->max_cert_list;
 614         else
 615                 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
 616
 617         if ((msg_hdr->frag_off+frag_len) > max_len)
 618                 goto err;
 619
 620         /* Try to find item in queue */
 621         pq_64bit_init(&seq64);
 622         pq_64bit_assign_word(&seq64, msg_hdr->seq);
 623         item = pqueue_find(s->d1->buffered_messages, seq64);
 624         pq_64bit_free(&seq64);
 625
 626         if (item == NULL)
 627                 {
 628                 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
 629                 if ( frag == NULL)
 630                         goto err;
 631                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 632                 frag->msg_header.frag_len = frag->msg_header.msg_len;
 633                 frag->msg_header.frag_off = 0;
 634                 }
 635         else
 636                 frag = (hm_fragment*) item->data;
 637
 638         /* If message is already reassembled, this must be a
 639          * retransmit and can be dropped.
 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 (i<=0 || (unsigned long)i!=frag_len)
 660                 goto err;
 661
 662         RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
 663                             (long)(msg_hdr->frag_off + frag_len));
 664
 665         RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
 666                                    is_complete);
 667
 668         if (is_complete)
 669                 {
 670                 OPENSSL_free(frag->reassembly);
 671                 frag->reassembly = NULL;
 672                 }
 673
 674         if (item == NULL)
 675                 {
 676                 pq_64bit_init(&seq64);
 677                 pq_64bit_assign_word(&seq64, msg_hdr->seq);
 678                 item = pitem_new(seq64, frag);
 679                 pq_64bit_free(&seq64);
 680
 681                 if (item == NULL)
 682                         {
 683                         goto err;
 684                         i = -1;
 685                         }
 686
 687                 pqueue_insert(s->d1->buffered_messages, item);
 688                 }
 689
 690         return DTLS1_HM_FRAGMENT_RETRY;
 691
 692 err:
 693         if (frag != NULL) dtls1_hm_fragment_free(frag);
 694         if (item != NULL) OPENSSL_free(item);
 695         *ok = 0;
 696         return i;
 697         }
 698
 699
 700 static int
 701 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
 702 {
 703         int i=-1;
 704         hm_fragment *frag = NULL;
 705         pitem *item = NULL;
 706         PQ_64BIT seq64;
 707         unsigned long frag_len = msg_hdr->frag_len;
 708
 709         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 710                 goto err;
 711
 712         /* Try to find item in queue, to prevent duplicate entries */
 713         pq_64bit_init(&seq64);
 714         pq_64bit_assign_word(&seq64, msg_hdr->seq);
 715         item = pqueue_find(s->d1->buffered_messages, seq64);
 716         pq_64bit_free(&seq64);
 717
 718         /* If we already have an entry and this one is a fragment,
 719          * don't discard it and rather try to reassemble it.
 720          */
 721         if (item != NULL && frag_len < msg_hdr->msg_len)
 722                 item = NULL;
 723
 724         /* Discard the message if sequence number was already there, is
 725          * too far in the future, already in the queue or if we received
 726          * a FINISHED before the SERVER_HELLO, which then must be a stale
 727          * retransmit.
 728          */
 729         if (msg_hdr->seq <= s->d1->handshake_read_seq ||
 730                 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
 731                 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
 732                 {
 733                 unsigned char devnull [256];
 734
 735                 while (frag_len)
 736                         {
 737                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 738                                 devnull,
 739                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 740                         if (i<=0) goto err;
 741                         frag_len -= i;
 742                         }
 743                 }
 744         else
 745                 {
 746                 if (frag_len && frag_len < msg_hdr->msg_len)
 747                         return dtls1_reassemble_fragment(s, msg_hdr, ok);
 748
 749                 frag = dtls1_hm_fragment_new(frag_len, 0);
 750                 if ( frag == NULL)
 751                         goto err;
 752
 753                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 754
 755                 if (frag_len)
 756                         {
 757                         /* read the body of the fragment (header has already been read) */
 758                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 759                                 frag->fragment,frag_len,0);
 760                         if (i<=0 || (unsigned long)i!=frag_len)
 761                                 goto err;
 762                         }
 763
 764                 pq_64bit_init(&seq64);
 765                 pq_64bit_assign_word(&seq64, msg_hdr->seq);
 766
 767                 item = pitem_new(seq64, frag);
 768                 pq_64bit_free(&seq64);
 769                 if ( item == NULL)
 770                         goto err;
 771
 772                 pqueue_insert(s->d1->buffered_messages, item);
 773                 }
 774
 775         return DTLS1_HM_FRAGMENT_RETRY;
 776
 777 err:
 778         if ( frag != NULL) dtls1_hm_fragment_free(frag);
 779         if ( item != NULL) OPENSSL_free(item);
 780         *ok = 0;
 781         return i;
 782         }
 783
 784
 785 static long
 786 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 787         {
 788         unsigned char wire[DTLS1_HM_HEADER_LENGTH];
 789         unsigned long len, frag_off, frag_len;
 790         int i,al;
 791         struct hm_header_st msg_hdr;
 792
 793         /* see if we have the required fragment already */
 794         if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
 795                 {
 796                 if (*ok)        s->init_num = frag_len;
 797                 return frag_len;
 798                 }
 799
 800         /* read handshake message header */
 801         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
 802                 DTLS1_HM_HEADER_LENGTH, 0);
 803         if (i <= 0)     /* nbio, or an error */
 804                 {
 805                 s->rwstate=SSL_READING;
 806                 *ok = 0;
 807                 return i;
 808                 }
 809         OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
 810
 811         /* parse the message fragment header */
 812         dtls1_get_message_header(wire, &msg_hdr);
 813
 814         /*
 815          * if this is a future (or stale) message it gets buffered
 816          * (or dropped)--no further processing at this time
 817          */
 818         if ( msg_hdr.seq != s->d1->handshake_read_seq)
 819                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 820
 821         len = msg_hdr.msg_len;
 822         frag_off = msg_hdr.frag_off;
 823         frag_len = msg_hdr.frag_len;
 824
 825         if (frag_len && frag_len < len)
 826                 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
 827
 828         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 829                 wire[0] == SSL3_MT_HELLO_REQUEST)
 830                 {
 831                 /* The server may always send 'Hello Request' messages --
 832                  * we are doing a handshake anyway now, so ignore them
 833                  * if their format is correct. Does not count for
 834                  * 'Finished' MAC. */
 835                 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
 836                         {
 837                         if (s->msg_callback)
 838                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 839                                         wire, DTLS1_HM_HEADER_LENGTH, s,
 840                                         s->msg_callback_arg);
 841
 842                         s->init_num = 0;
 843                         return dtls1_get_message_fragment(s, st1, stn,
 844                                 max, ok);
 845                         }
 846                 else /* Incorrectly formated Hello request */
 847                         {
 848                         al=SSL_AD_UNEXPECTED_MESSAGE;
 849                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 850                         goto f_err;
 851                         }
 852                 }
 853
 854         if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
 855                 goto f_err;
 856
 857         /* XDTLS:  ressurect this when restart is in place */
 858         s->state=stn;
 859
 860         if ( frag_len > 0)
 861                 {
 862                 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 863
 864                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 865                         &p[frag_off],frag_len,0);
 866                 /* XDTLS:  fix this--message fragments cannot span multiple packets */
 867                 if (i <= 0)
 868                         {
 869                         s->rwstate=SSL_READING;
 870                         *ok = 0;
 871                         return i;
 872                         }
 873                 }
 874         else
 875                 i = 0;
 876
 877         /* XDTLS:  an incorrectly formatted fragment should cause the
 878          * handshake to fail */
 879         OPENSSL_assert(i == (int)frag_len);
 880
 881         *ok = 1;
 882
 883         /* Note that s->init_num is *not* used as current offset in
 884          * s->init_buf->data, but as a counter summing up fragments'
 885          * lengths: as soon as they sum up to handshake packet
 886          * length, we assume we have got all the fragments. */
 887         s->init_num = frag_len;
 888         return frag_len;
 889
 890 f_err:
 891         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 892         s->init_num = 0;
 893
 894         *ok=0;
 895         return(-1);
 896         }
 897
 898 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
 899         {
 900         unsigned char *p,*d;
 901         int i;
 902         unsigned long l;
 903
 904         if (s->state == a)
 905                 {
 906                 d=(unsigned char *)s->init_buf->data;
 907                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
 908
 909                 i=s->method->ssl3_enc->final_finish_mac(s,
 910                         &(s->s3->finish_dgst1),
 911                         &(s->s3->finish_dgst2),
 912                         sender,slen,s->s3->tmp.finish_md);
 913                 s->s3->tmp.finish_md_len = i;
 914                 memcpy(p, s->s3->tmp.finish_md, i);
 915                 p+=i;
 916                 l=i;
 917
 918         /* Copy the finished so we can use it for
 919          * renegotiation checks
 920          */
 921         if(s->type == SSL_ST_CONNECT)
 922                 {
 923                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 924                 memcpy(s->s3->previous_client_finished,
 925                        s->s3->tmp.finish_md, i);
 926                 s->s3->previous_client_finished_len=i;
 927                 }
 928         else
 929                 {
 930                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
 931                 memcpy(s->s3->previous_server_finished,
 932                        s->s3->tmp.finish_md, i);
 933                 s->s3->previous_server_finished_len=i;
 934                 }
 935
 936 #ifdef OPENSSL_SYS_WIN16
 937                 /* MSVC 1.5 does not clear the top bytes of the word unless
 938                  * I do this.
 939                  */
 940                 l&=0xffff;
 941 #endif
 942
 943                 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
 944                 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
 945                 s->init_off=0;
 946
 947                 /* buffer the message to handle re-xmits */
 948                 dtls1_buffer_message(s, 0);
 949
 950                 s->state=b;
 951                 }
 952
 953         /* SSL3_ST_SEND_xxxxxx_HELLO_B */
 954         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 955         }
 956
 957 /* for these 2 messages, we need to
 958  * ssl->enc_read_ctx                    re-init
 959  * ssl->s3->read_sequence               zero
 960  * ssl->s3->read_mac_secret             re-init
 961  * ssl->session->read_sym_enc           assign
 962  * ssl->session->read_compression       assign
 963  * ssl->session->read_hash              assign
 964  */
 965 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
 966         {
 967         unsigned char *p;
 968
 969         if (s->state == a)
 970                 {
 971                 p=(unsigned char *)s->init_buf->data;
 972                 *p++=SSL3_MT_CCS;
 973                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
 974                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
 975
 976                 if (s->client_version == DTLS1_BAD_VER)
 977                         {
 978                         s->d1->next_handshake_write_seq++;
 979                         s2n(s->d1->handshake_write_seq,p);
 980                         s->init_num+=2;
 981                         }
 982
 983                 s->init_off=0;
 984
 985                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
 986                         s->d1->handshake_write_seq, 0, 0);
 987
 988                 /* buffer the message to handle re-xmits */
 989                 dtls1_buffer_message(s, 1);
 990
 991                 s->state=b;
 992                 }
 993
 994         /* SSL3_ST_CW_CHANGE_B */
 995         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
 996         }
 997
 998 static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
 999         {
1000                 int n;
1001                 unsigned char *p;
1002
1003                 n=i2d_X509(x,NULL);
1004                 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
1005                         {
1006                         SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
1007                         return 0;
1008                         }
1009                 p=(unsigned char *)&(buf->data[*l]);
1010                 l2n3(n,p);
1011                 i2d_X509(x,&p);
1012                 *l+=n+3;
1013
1014                 return 1;
1015         }
1016 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
1017         {
1018         unsigned char *p;
1019         int i;
1020         unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
1021         BUF_MEM *buf;
1022
1023         /* TLSv1 sends a chain with nothing in it, instead of an alert */
1024         buf=s->init_buf;
1025         if (!BUF_MEM_grow_clean(buf,10))
1026                 {
1027                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
1028                 return(0);
1029                 }
1030         if (x != NULL)
1031                 {
1032                 X509_STORE_CTX xs_ctx;
1033
1034                 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
1035                         {
1036                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
1037                         return(0);
1038                         }
1039
1040                 X509_verify_cert(&xs_ctx);
1041                 /* Don't leave errors in the queue */
1042                 ERR_clear_error();
1043                 for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
1044                         {
1045                         x = sk_X509_value(xs_ctx.chain, i);
1046
1047                         if (!dtls1_add_cert_to_buf(buf, &l, x))
1048                                 {
1049                                 X509_STORE_CTX_cleanup(&xs_ctx);
1050                                 return 0;
1051                                 }
1052                         }
1053                 X509_STORE_CTX_cleanup(&xs_ctx);
1054                 }
1055         /* Thawte special :-) */
1056         for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
1057                 {
1058                 x=sk_X509_value(s->ctx->extra_certs,i);
1059                 if (!dtls1_add_cert_to_buf(buf, &l, x))
1060                         return 0;
1061                 }
1062
1063         l-= (3 + DTLS1_HM_HEADER_LENGTH);
1064
1065         p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1066         l2n3(l,p);
1067         l+=3;
1068         p=(unsigned char *)&(buf->data[0]);
1069         p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1070
1071         l+=DTLS1_HM_HEADER_LENGTH;
1072         return(l);
1073         }
1074
1075 int dtls1_read_failed(SSL *s, int code)
1076         {
1077         if ( code > 0)
1078                 {
1079                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1080                 return 1;
1081                 }
1082
1083         if (!dtls1_is_timer_expired(s))
1084                 {
1085                 /* not a timeout, none of our business,
1086                    let higher layers handle this.  in fact it's probably an error */
1087                 return code;
1088                 }
1089
1090         if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
1091                 {
1092                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1093                 return code;
1094                 }
1095
1096 #if 0 /* for now, each alert contains only one record number */
1097         item = pqueue_peek(state->rcvd_records);
1098         if ( item )
1099                 {
1100                 /* send an alert immediately for all the missing records */
1101                 }
1102         else
1103 #endif
1104
1105 #if 0  /* no more alert sending, just retransmit the last set of messages */
1106         if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1107                 ssl3_send_alert(s,SSL3_AL_WARNING,
1108                         DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1109 #endif
1110
1111         return dtls1_handle_timeout(s);
1112         }
1113
1114 int
1115 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1116         {
1117         /* The index of the retransmission queue actually is the message sequence number,
1118          * since the queue only contains messages of a single handshake. However, the
1119          * ChangeCipherSpec has no message sequence number and so using only the sequence
1120          * will result in the CCS and Finished having the same index. To prevent this,
1121          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1122          * This does not only differ CSS and Finished, it also maintains the order of the
1123          * index (important for priority queues) and fits in the unsigned short variable.
1124          */
1125         return seq * 2 - is_ccs;
1126         }
1127
1128 int
1129 dtls1_retransmit_buffered_messages(SSL *s)
1130         {
1131         pqueue sent = s->d1->sent_messages;
1132         piterator iter;
1133         pitem *item;
1134         hm_fragment *frag;
1135         int found = 0;
1136
1137         iter = pqueue_iterator(sent);
1138
1139         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1140                 {
1141                 frag = (hm_fragment *)item->data;
1142                         if ( dtls1_retransmit_message(s,
1143                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1144                                 0, &found) <= 0 && found)
1145                         {
1146                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1147                         return -1;
1148                         }
1149                 }
1150
1151         return 1;
1152         }
1153
1154 int
1155 dtls1_buffer_message(SSL *s, int is_ccs)
1156         {
1157         pitem *item;
1158         hm_fragment *frag;
1159         PQ_64BIT seq64;
1160
1161         /* this function is called immediately after a message has
1162          * been serialized */
1163         OPENSSL_assert(s->init_off == 0);
1164
1165         frag = dtls1_hm_fragment_new(s->init_num, 0);
1166
1167         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1168
1169         if ( is_ccs)
1170                 {
1171                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1172                         DTLS1_CCS_HEADER_LENGTH <= (unsigned int)s->init_num);
1173                 }
1174         else
1175                 {
1176                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1177                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1178                 }
1179
1180         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1181         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1182         frag->msg_header.type = s->d1->w_msg_hdr.type;
1183         frag->msg_header.frag_off = 0;
1184         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1185         frag->msg_header.is_ccs = is_ccs;
1186
1187         /* save current state*/
1188         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1189         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1190         frag->msg_header.saved_retransmit_state.compress = s->compress;
1191         frag->msg_header.saved_retransmit_state.session = s->session;
1192         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1193
1194         pq_64bit_init(&seq64);
1195
1196         pq_64bit_assign_word(&seq64,
1197                                                  dtls1_get_queue_priority(frag->msg_header.seq,
1198                                                                                                   frag->msg_header.is_ccs));
1199
1200         item = pitem_new(seq64, frag);
1201         pq_64bit_free(&seq64);
1202         if ( item == NULL)
1203                 {
1204                 dtls1_hm_fragment_free(frag);
1205                 return 0;
1206                 }
1207
1208 #if 0
1209         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1210         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1211         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1212 #endif
1213
1214         pqueue_insert(s->d1->sent_messages, item);
1215         return 1;
1216         }
1217
1218 int
1219 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1220         int *found)
1221         {
1222         int ret;
1223         /* XDTLS: for now assuming that read/writes are blocking */
1224         pitem *item;
1225         hm_fragment *frag ;
1226         unsigned long header_length;
1227         PQ_64BIT seq64;
1228         struct dtls1_retransmit_state saved_state;
1229         unsigned char save_write_sequence[8];
1230
1231         /*
1232           OPENSSL_assert(s->init_num == 0);
1233           OPENSSL_assert(s->init_off == 0);
1234          */
1235
1236         /* XDTLS:  the requested message ought to be found, otherwise error */
1237         pq_64bit_init(&seq64);
1238         pq_64bit_assign_word(&seq64, seq);
1239
1240         item = pqueue_find(s->d1->sent_messages, seq64);
1241         pq_64bit_free(&seq64);
1242         if ( item == NULL)
1243                 {
1244                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1245                 *found = 0;
1246                 return 0;
1247                 }
1248
1249         *found = 1;
1250         frag = (hm_fragment *)item->data;
1251
1252         if ( frag->msg_header.is_ccs)
1253                 header_length = DTLS1_CCS_HEADER_LENGTH;
1254         else
1255                 header_length = DTLS1_HM_HEADER_LENGTH;
1256
1257         memcpy(s->init_buf->data, frag->fragment,
1258                 frag->msg_header.msg_len + header_length);
1259                 s->init_num = frag->msg_header.msg_len + header_length;
1260
1261         dtls1_set_message_header_int(s, frag->msg_header.type,
1262                 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1263                 frag->msg_header.frag_len);
1264
1265         /* save current state */
1266         saved_state.enc_write_ctx = s->enc_write_ctx;
1267         saved_state.write_hash = s->write_hash;
1268         saved_state.compress = s->compress;
1269         saved_state.session = s->session;
1270         saved_state.epoch = s->d1->w_epoch;
1271         saved_state.epoch = s->d1->w_epoch;
1272
1273         s->d1->retransmitting = 1;
1274
1275         /* restore state in which the message was originally sent */
1276         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1277         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1278         s->compress = frag->msg_header.saved_retransmit_state.compress;
1279         s->session = frag->msg_header.saved_retransmit_state.session;
1280         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1281
1282         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1283         {
1284                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1285                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1286         }
1287
1288         ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1289                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1290
1291         /* restore current state */
1292         s->enc_write_ctx = saved_state.enc_write_ctx;
1293         s->write_hash = saved_state.write_hash;
1294         s->compress = saved_state.compress;
1295         s->session = saved_state.session;
1296         s->d1->w_epoch = saved_state.epoch;
1297
1298         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1299         {
1300                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1301                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1302         }
1303
1304         s->d1->retransmitting = 0;
1305
1306         (void)BIO_flush(SSL_get_wbio(s));
1307         return ret;
1308         }
1309
1310 /* call this function when the buffered messages are no longer needed */
1311 void
1312 dtls1_clear_record_buffer(SSL *s)
1313         {
1314         pitem *item;
1315
1316         for(item = pqueue_pop(s->d1->sent_messages);
1317                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1318                 {
1319                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1320                 pitem_free(item);
1321                 }
1322         }
1323
1324
1325 unsigned char *
1326 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1327                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1328         {
1329         if ( frag_off == 0)
1330                 {
1331                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1332                 s->d1->next_handshake_write_seq++;
1333                 }
1334
1335         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1336                 frag_off, frag_len);
1337
1338         return p += DTLS1_HM_HEADER_LENGTH;
1339         }
1340
1341
1342 /* don't actually do the writing, wait till the MTU has been retrieved */
1343 static void
1344 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1345                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1346                             unsigned long frag_len)
1347         {
1348         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1349
1350         msg_hdr->type = mt;
1351         msg_hdr->msg_len = len;
1352         msg_hdr->seq = seq_num;
1353         msg_hdr->frag_off = frag_off;
1354         msg_hdr->frag_len = frag_len;
1355         }
1356
1357 static void
1358 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1359                         unsigned long frag_len)
1360         {
1361         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1362
1363         msg_hdr->frag_off = frag_off;
1364         msg_hdr->frag_len = frag_len;
1365         }
1366
1367 static unsigned char *
1368 dtls1_write_message_header(SSL *s, unsigned char *p)
1369         {
1370         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1371
1372         *p++ = msg_hdr->type;
1373         l2n3(msg_hdr->msg_len, p);
1374
1375         s2n(msg_hdr->seq, p);
1376         l2n3(msg_hdr->frag_off, p);
1377         l2n3(msg_hdr->frag_len, p);
1378
1379         return p;
1380         }
1381
1382 static unsigned int
1383 dtls1_min_mtu(void)
1384         {
1385         return (g_probable_mtu[(sizeof(g_probable_mtu) /
1386                 sizeof(g_probable_mtu[0])) - 1]);
1387         }
1388
1389 static unsigned int
1390 dtls1_guess_mtu(unsigned int curr_mtu)
1391         {
1392         size_t i;
1393
1394         if ( curr_mtu == 0 )
1395                 return g_probable_mtu[0] ;
1396
1397         for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1398                 if ( curr_mtu > g_probable_mtu[i])
1399                         return g_probable_mtu[i];
1400
1401         return curr_mtu;
1402         }
1403
1404 void
1405 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1406         {
1407         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1408         msg_hdr->type = *(data++);
1409         n2l3(data, msg_hdr->msg_len);
1410
1411         n2s(data, msg_hdr->seq);
1412         n2l3(data, msg_hdr->frag_off);
1413         n2l3(data, msg_hdr->frag_len);
1414         }
1415
1416 void
1417 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1418         {
1419         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1420
1421         ccs_hdr->type = *(data++);
1422         }