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 const unsigned int g_probable_mtu[] = {1500, 512, 256};
 160
 161 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
 162         unsigned long frag_len);
 163 static unsigned char *dtls1_write_message_header(SSL *s,
 164         unsigned char *p);
 165 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
 166         unsigned long len, unsigned short seq_num, unsigned long frag_off,
 167         unsigned long frag_len);
 168 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
 169         long max, int *ok);
 170
 171 static hm_fragment *
 172 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
 173         {
 174         hm_fragment *frag = NULL;
 175         unsigned char *buf = NULL;
 176         unsigned char *bitmask = NULL;
 177
 178         frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
 179         if ( frag == NULL)
 180                 return NULL;
 181
 182         if (frag_len)
 183                 {
 184                 buf = (unsigned char *)OPENSSL_malloc(frag_len);
 185                 if ( buf == NULL)
 186                         {
 187                         OPENSSL_free(frag);
 188                         return NULL;
 189                         }
 190                 }
 191
 192         /* zero length fragment gets zero frag->fragment */
 193         frag->fragment = buf;
 194
 195         /* Initialize reassembly bitmask if necessary */
 196         if (reassembly)
 197                 {
 198                 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
 199                 if (bitmask == NULL)
 200                         {
 201                         if (buf != NULL) OPENSSL_free(buf);
 202                         OPENSSL_free(frag);
 203                         return NULL;
 204                         }
 205                 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
 206                 }
 207
 208         frag->reassembly = bitmask;
 209
 210         return frag;
 211         }
 212
 213 void dtls1_hm_fragment_free(hm_fragment *frag)
 214         {
 215
 216         if (frag->msg_header.is_ccs)
 217                 {
 218                 EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx);
 219                 EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash);
 220                 }
 221         if (frag->fragment) OPENSSL_free(frag->fragment);
 222         if (frag->reassembly) OPENSSL_free(frag->reassembly);
 223         OPENSSL_free(frag);
 224         }
 225
 226 static int dtls1_query_mtu(SSL *s)
 227 {
 228         if(s->d1->link_mtu)
 229                 {
 230                 s->d1->mtu = s->d1->link_mtu-BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
 231                 s->d1->link_mtu = 0;
 232                 }
 233
 234         /* AHA!  Figure out the MTU, and stick to the right size */
 235         if (s->d1->mtu < dtls1_min_mtu(s))
 236                 {
 237                 if(!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 238                         {
 239                         s->d1->mtu =
 240                                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 241
 242                         /* I've seen the kernel return bogus numbers when it doesn't know
 243                          * (initial write), so just make sure we have a reasonable number */
 244                         if (s->d1->mtu < dtls1_min_mtu(s))
 245                                 {
 246                                 /* Set to min mtu */
 247                                 s->d1->mtu = dtls1_min_mtu(s);
 248                                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
 249                                         s->d1->mtu, NULL);
 250                                 }
 251                         }
 252                 else
 253                         return 0;
 254                 }
 255         return 1;
 256 }
 257
 258 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
 259 int dtls1_do_write(SSL *s, int type)
 260         {
 261         int ret;
 262         unsigned int curr_mtu;
 263         int retry = 1;
 264         unsigned int len, frag_off, mac_size, blocksize, used_len;
 265
 266         if(!dtls1_query_mtu(s))
 267                 return -1;
 268
 269         OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu(s));  /* should have something reasonable now */
 270
 271         if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
 272                 OPENSSL_assert(s->init_num ==
 273                         (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
 274
 275         if (s->write_hash)
 276                 mac_size = EVP_MD_CTX_size(s->write_hash);
 277         else
 278                 mac_size = 0;
 279
 280         if (s->enc_write_ctx &&
 281                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))
 282                 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
 283         else
 284                 blocksize = 0;
 285
 286         frag_off = 0;
 287         /* s->init_num shouldn't ever be < 0...but just in case */
 288         while(s->init_num > 0)
 289                 {
 290                 used_len = BIO_wpending(SSL_get_wbio(s)) +  DTLS1_RT_HEADER_LENGTH
 291                         + mac_size + blocksize;
 292                 if(s->d1->mtu > used_len)
 293                         curr_mtu = s->d1->mtu - used_len;
 294                 else
 295                         curr_mtu = 0;
 296
 297                 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
 298                         {
 299                         /* grr.. we could get an error if MTU picked was wrong */
 300                         ret = BIO_flush(SSL_get_wbio(s));
 301                         if ( ret <= 0)
 302                                 return ret;
 303                         used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize;
 304                         if(s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH)
 305                                 {
 306                                 curr_mtu = s->d1->mtu - used_len;
 307                                 }
 308                         else
 309                                 {
 310                                 /* Shouldn't happen */
 311                                 return -1;
 312                                 }
 313                         }
 314
 315                 /* We just checked that s->init_num > 0 so this cast should be safe */
 316                 if (((unsigned int)s->init_num) > curr_mtu)
 317                         len = curr_mtu;
 318                 else
 319                         len = s->init_num;
 320
 321                 /* Shouldn't ever happen */
 322                 if(len > INT_MAX)
 323                         len = INT_MAX;
 324
 325                 /* XDTLS: this function is too long.  split out the CCS part */
 326                 if ( type == SSL3_RT_HANDSHAKE)
 327                         {
 328                         if ( s->init_off != 0)
 329                                 {
 330                                 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
 331                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
 332                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
 333
 334                                 /* We just checked that s->init_num > 0 so this cast should be safe */
 335                                 if (((unsigned int)s->init_num) > curr_mtu)
 336                                         len = curr_mtu;
 337                                 else
 338                                         len = s->init_num;
 339                                 }
 340
 341                         /* Shouldn't ever happen */
 342                         if(len > INT_MAX)
 343                                 len = INT_MAX;
 344
 345                         if ( len < DTLS1_HM_HEADER_LENGTH )
 346                                 {
 347                                 /*
 348                                  * len is so small that we really can't do anything sensible
 349                                  * so fail
 350                                  */
 351                                 return -1;
 352                                 }
 353                         dtls1_fix_message_header(s, frag_off,
 354                                 len - DTLS1_HM_HEADER_LENGTH);
 355
 356                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
 357                         }
 358
 359                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
 360                         len);
 361                 if (ret < 0)
 362                         {
 363                         /* might need to update MTU here, but we don't know
 364                          * which previous packet caused the failure -- so can't
 365                          * really retransmit anything.  continue as if everything
 366                          * is fine and wait for an alert to handle the
 367                          * retransmit
 368                          */
 369                         if ( retry && BIO_ctrl(SSL_get_wbio(s),
 370                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
 371                                 {
 372                                 if(!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 373                                         {
 374                                         if(!dtls1_query_mtu(s))
 375                                                 return -1;
 376                                         /* Have one more go */
 377                                         retry = 0;
 378                                         }
 379                                 else
 380                                         return -1;
 381                                 }
 382                         else
 383                                 {
 384                                 return(-1);
 385                                 }
 386                         }
 387                 else
 388                         {
 389
 390                         /* bad if this assert fails, only part of the handshake
 391                          * message got sent.  but why would this happen? */
 392                         OPENSSL_assert(len == (unsigned int)ret);
 393
 394                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
 395                                 {
 396                                 /* should not be done for 'Hello Request's, but in that case
 397                                  * we'll ignore the result anyway */
 398                                 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
 399                                 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
 400                                 int xlen;
 401
 402                                 if (frag_off == 0 && s->version != DTLS1_BAD_VER)
 403                                         {
 404                                         /* reconstruct message header is if it
 405                                          * is being sent in single fragment */
 406                                         *p++ = msg_hdr->type;
 407                                         l2n3(msg_hdr->msg_len,p);
 408                                         s2n (msg_hdr->seq,p);
 409                                         l2n3(0,p);
 410                                         l2n3(msg_hdr->msg_len,p);
 411                                         p  -= DTLS1_HM_HEADER_LENGTH;
 412                                         xlen = ret;
 413                                         }
 414                                 else
 415                                         {
 416                                         p  += DTLS1_HM_HEADER_LENGTH;
 417                                         xlen = ret - DTLS1_HM_HEADER_LENGTH;
 418                                         }
 419
 420                                 ssl3_finish_mac(s, p, xlen);
 421                                 }
 422
 423                         if (ret == s->init_num)
 424                                 {
 425                                 if (s->msg_callback)
 426                                         s->msg_callback(1, s->version, type, s->init_buf->data,
 427                                                 (size_t)(s->init_off + s->init_num), s,
 428                                                 s->msg_callback_arg);
 429
 430                                 s->init_off = 0;  /* done writing this message */
 431                                 s->init_num = 0;
 432
 433                                 return(1);
 434                                 }
 435                         s->init_off+=ret;
 436                         s->init_num-=ret;
 437                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
 438                         }
 439                 }
 440         return(0);
 441         }
 442
 443
 444 /* Obtain handshake message of message type 'mt' (any if mt == -1),
 445  * maximum acceptable body length 'max'.
 446  * Read an entire handshake message.  Handshake messages arrive in
 447  * fragments.
 448  */
 449 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 450         {
 451         int i, al;
 452         struct hm_header_st *msg_hdr;
 453         unsigned char *p;
 454         unsigned long msg_len;
 455
 456         /* s3->tmp is used to store messages that are unexpected, caused
 457          * by the absence of an optional handshake message */
 458         if (s->s3->tmp.reuse_message)
 459                 {
 460                 s->s3->tmp.reuse_message=0;
 461                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
 462                         {
 463                         al=SSL_AD_UNEXPECTED_MESSAGE;
 464                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
 465                         goto f_err;
 466                         }
 467                 *ok=1;
 468                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 469                 s->init_num = (int)s->s3->tmp.message_size;
 470                 return s->init_num;
 471                 }
 472
 473         msg_hdr = &s->d1->r_msg_hdr;
 474         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 475
 476 again:
 477         i = dtls1_get_message_fragment(s, st1, stn, max, ok);
 478         if ( i == DTLS1_HM_BAD_FRAGMENT ||
 479                 i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
 480                 goto again;
 481         else if ( i <= 0 && !*ok)
 482                 return i;
 483
 484     if (mt >= 0 && s->s3->tmp.message_type != mt) {
 485         al = SSL_AD_UNEXPECTED_MESSAGE;
 486         SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
 487         goto f_err;
 488     }
 489
 490         p = (unsigned char *)s->init_buf->data;
 491         msg_len = msg_hdr->msg_len;
 492
 493         /* reconstruct message header */
 494         *(p++) = msg_hdr->type;
 495         l2n3(msg_len,p);
 496         s2n (msg_hdr->seq,p);
 497         l2n3(0,p);
 498         l2n3(msg_len,p);
 499         if (s->version != DTLS1_BAD_VER) {
 500                 p       -= DTLS1_HM_HEADER_LENGTH;
 501                 msg_len += DTLS1_HM_HEADER_LENGTH;
 502         }
 503
 504         ssl3_finish_mac(s, p, msg_len);
 505         if (s->msg_callback)
 506                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 507                         p, msg_len,
 508                         s, s->msg_callback_arg);
 509
 510         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 511
 512         /* Don't change sequence numbers while listening */
 513         if (!s->d1->listen)
 514                 s->d1->handshake_read_seq++;
 515
 516         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 517         return s->init_num;
 518
 519 f_err:
 520         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 521         *ok = 0;
 522         return -1;
 523         }
 524
 525
 526 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
 527         {
 528         size_t frag_off,frag_len,msg_len;
 529
 530         msg_len  = msg_hdr->msg_len;
 531         frag_off = msg_hdr->frag_off;
 532         frag_len = msg_hdr->frag_len;
 533
 534         /* sanity checking */
 535         if ( (frag_off+frag_len) > msg_len)
 536                 {
 537                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 538                 return SSL_AD_ILLEGAL_PARAMETER;
 539                 }
 540
 541         if ( (frag_off+frag_len) > (unsigned long)max)
 542                 {
 543                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 544                 return SSL_AD_ILLEGAL_PARAMETER;
 545                 }
 546
 547         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 548                 {
 549                 /* msg_len is limited to 2^24, but is effectively checked
 550                  * against max above */
 551                 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH))
 552                         {
 553                         SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
 554                         return SSL_AD_INTERNAL_ERROR;
 555                         }
 556
 557                 s->s3->tmp.message_size  = msg_len;
 558                 s->d1->r_msg_hdr.msg_len = msg_len;
 559                 s->s3->tmp.message_type  = msg_hdr->type;
 560                 s->d1->r_msg_hdr.type    = msg_hdr->type;
 561                 s->d1->r_msg_hdr.seq     = msg_hdr->seq;
 562                 }
 563         else if (msg_len != s->d1->r_msg_hdr.msg_len)
 564                 {
 565                 /* They must be playing with us! BTW, failure to enforce
 566                  * upper limit would open possibility for buffer overrun. */
 567                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 568                 return SSL_AD_ILLEGAL_PARAMETER;
 569                 }
 570
 571         return 0; /* no error */
 572         }
 573
 574
 575 static int
 576 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
 577         {
 578         /* (0) check whether the desired fragment is available
 579          * if so:
 580          * (1) copy over the fragment to s->init_buf->data[]
 581          * (2) update s->init_num
 582          */
 583         pitem *item;
 584         hm_fragment *frag;
 585         int al;
 586
 587         *ok = 0;
 588         item = pqueue_peek(s->d1->buffered_messages);
 589         if ( item == NULL)
 590                 return 0;
 591
 592         frag = (hm_fragment *)item->data;
 593
 594         /* Don't return if reassembly still in progress */
 595         if (frag->reassembly != NULL)
 596                 return 0;
 597
 598         if ( s->d1->handshake_read_seq == frag->msg_header.seq)
 599                 {
 600                 unsigned long frag_len = frag->msg_header.frag_len;
 601                 pqueue_pop(s->d1->buffered_messages);
 602
 603                 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
 604
 605                 if (al==0) /* no alert */
 606                         {
 607                         unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 608                         memcpy(&p[frag->msg_header.frag_off],
 609                                 frag->fragment,frag->msg_header.frag_len);
 610                         }
 611
 612                 dtls1_hm_fragment_free(frag);
 613                 pitem_free(item);
 614
 615                 if (al==0)
 616                         {
 617                         *ok = 1;
 618                         return frag_len;
 619                         }
 620
 621                 ssl3_send_alert(s,SSL3_AL_FATAL,al);
 622                 s->init_num = 0;
 623                 *ok = 0;
 624                 return -1;
 625                 }
 626         else
 627                 return 0;
 628         }
 629
 630 /* dtls1_max_handshake_message_len returns the maximum number of bytes
 631  * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may
 632  * be greater if the maximum certificate list size requires it. */
 633 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
 634         {
 635         unsigned long max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
 636         if (max_len < (unsigned long)s->max_cert_list)
 637                 return s->max_cert_list;
 638         return max_len;
 639         }
 640
 641 static int
 642 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 643         {
 644         hm_fragment *frag = NULL;
 645         pitem *item = NULL;
 646         int i = -1, is_complete;
 647         unsigned char seq64be[8];
 648         unsigned long frag_len = msg_hdr->frag_len;
 649
 650         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len ||
 651             msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
 652                 goto err;
 653
 654         if (frag_len == 0)
 655                 return DTLS1_HM_FRAGMENT_RETRY;
 656
 657         /* Try to find item in queue */
 658         memset(seq64be,0,sizeof(seq64be));
 659         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 660         seq64be[7] = (unsigned char) msg_hdr->seq;
 661         item = pqueue_find(s->d1->buffered_messages, seq64be);
 662
 663         if (item == NULL)
 664                 {
 665                 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
 666                 if ( frag == NULL)
 667                         goto err;
 668                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 669                 frag->msg_header.frag_len = frag->msg_header.msg_len;
 670                 frag->msg_header.frag_off = 0;
 671                 }
 672         else
 673                 {
 674                 frag = (hm_fragment*) item->data;
 675                 if (frag->msg_header.msg_len != msg_hdr->msg_len)
 676                         {
 677                         item = NULL;
 678                         frag = NULL;
 679                         goto err;
 680                         }
 681                 }
 682
 683
 684         /* If message is already reassembled, this must be a
 685          * retransmit and can be dropped. In this case item != NULL and so frag
 686          * does not need to be freed.
 687          */
 688         if (frag->reassembly == NULL)
 689                 {
 690                 unsigned char devnull [256];
 691
 692                 while (frag_len)
 693                         {
 694                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 695                                 devnull,
 696                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 697                         if (i<=0) goto err;
 698                         frag_len -= i;
 699                         }
 700                 return DTLS1_HM_FRAGMENT_RETRY;
 701                 }
 702
 703         /* read the body of the fragment (header has already been read */
 704         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 705                 frag->fragment + msg_hdr->frag_off,frag_len,0);
 706         if ((unsigned long)i!=frag_len)
 707                 i=-1;
 708         if (i<=0)
 709                 goto err;
 710
 711         RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
 712                             (long)(msg_hdr->frag_off + frag_len));
 713
 714         RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
 715                                    is_complete);
 716
 717         if (is_complete)
 718                 {
 719                 OPENSSL_free(frag->reassembly);
 720                 frag->reassembly = NULL;
 721                 }
 722
 723         if (item == NULL)
 724                 {
 725                 item = pitem_new(seq64be, frag);
 726                 if (item == NULL)
 727                         {
 728                         i = -1;
 729                         goto err;
 730                         }
 731
 732                 item = pqueue_insert(s->d1->buffered_messages, item);
 733                 /* pqueue_insert fails iff a duplicate item is inserted.
 734                  * However, |item| cannot be a duplicate. If it were,
 735                  * |pqueue_find|, above, would have returned it and control
 736                  * would never have reached this branch. */
 737                 OPENSSL_assert(item != NULL);
 738                 }
 739
 740         return DTLS1_HM_FRAGMENT_RETRY;
 741
 742 err:
 743         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 744         *ok = 0;
 745         return i;
 746         }
 747
 748
 749 static int
 750 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 751 {
 752         int i=-1;
 753         hm_fragment *frag = NULL;
 754         pitem *item = NULL;
 755         unsigned char seq64be[8];
 756         unsigned long frag_len = msg_hdr->frag_len;
 757
 758         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
 759                 goto err;
 760
 761         /* Try to find item in queue, to prevent duplicate entries */
 762         memset(seq64be,0,sizeof(seq64be));
 763         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
 764         seq64be[7] = (unsigned char) msg_hdr->seq;
 765         item = pqueue_find(s->d1->buffered_messages, seq64be);
 766
 767         /* If we already have an entry and this one is a fragment,
 768          * don't discard it and rather try to reassemble it.
 769          */
 770         if (item != NULL && frag_len != msg_hdr->msg_len)
 771                 item = NULL;
 772
 773         /* Discard the message if sequence number was already there, is
 774          * too far in the future, already in the queue or if we received
 775          * a FINISHED before the SERVER_HELLO, which then must be a stale
 776          * retransmit.
 777          */
 778         if (msg_hdr->seq <= s->d1->handshake_read_seq ||
 779                 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
 780                 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
 781                 {
 782                 unsigned char devnull [256];
 783
 784                 while (frag_len)
 785                         {
 786                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 787                                 devnull,
 788                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
 789                         if (i<=0) goto err;
 790                         frag_len -= i;
 791                         }
 792                 }
 793         else
 794                 {
 795                 if (frag_len != msg_hdr->msg_len)
 796                         return dtls1_reassemble_fragment(s, msg_hdr, ok);
 797
 798                 if (frag_len > dtls1_max_handshake_message_len(s))
 799                         goto err;
 800
 801                 frag = dtls1_hm_fragment_new(frag_len, 0);
 802                 if ( frag == NULL)
 803                         goto err;
 804
 805                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 806
 807                 if (frag_len)
 808                         {
 809                         /* read the body of the fragment (header has already been read */
 810                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 811                                 frag->fragment,frag_len,0);
 812                         if ((unsigned long)i!=frag_len)
 813                                 i = -1;
 814                         if (i<=0)
 815                                 goto err;
 816                         }
 817
 818                 item = pitem_new(seq64be, frag);
 819                 if ( item == NULL)
 820                         goto err;
 821
 822                 item = pqueue_insert(s->d1->buffered_messages, item);
 823                 /* pqueue_insert fails iff a duplicate item is inserted.
 824                  * However, |item| cannot be a duplicate. If it were,
 825                  * |pqueue_find|, above, would have returned it. Then, either
 826                  * |frag_len| != |msg_hdr->msg_len| in which case |item| is set
 827                  * to NULL and it will have been processed with
 828                  * |dtls1_reassemble_fragment|, above, or the record will have
 829                  * been discarded. */
 830                 OPENSSL_assert(item != NULL);
 831                 }
 832
 833         return DTLS1_HM_FRAGMENT_RETRY;
 834
 835 err:
 836         if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
 837         *ok = 0;
 838         return i;
 839         }
 840
 841
 842 static long
 843 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 844         {
 845         unsigned char wire[DTLS1_HM_HEADER_LENGTH];
 846         unsigned long len, frag_off, frag_len;
 847         int i,al;
 848         struct hm_header_st msg_hdr;
 849
 850         redo:
 851         /* see if we have the required fragment already */
 852         if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
 853                 {
 854                 if (*ok)        s->init_num = frag_len;
 855                 return frag_len;
 856                 }
 857
 858         /* read handshake message header */
 859         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
 860                 DTLS1_HM_HEADER_LENGTH, 0);
 861         if (i <= 0)     /* nbio, or an error */
 862                 {
 863                 s->rwstate=SSL_READING;
 864                 *ok = 0;
 865                 return i;
 866                 }
 867         /* Handshake fails if message header is incomplete */
 868         if (i != DTLS1_HM_HEADER_LENGTH)
 869                 {
 870                 al=SSL_AD_UNEXPECTED_MESSAGE;
 871                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 872                 goto f_err;
 873                 }
 874
 875         /* parse the message fragment header */
 876         dtls1_get_message_header(wire, &msg_hdr);
 877
 878     len = msg_hdr.msg_len;
 879     frag_off = msg_hdr.frag_off;
 880     frag_len = msg_hdr.frag_len;
 881
 882     /*
 883      * We must have at least frag_len bytes left in the record to be read.
 884      * Fragments must not span records.
 885      */
 886     if (frag_len > s->s3->rrec.length) {
 887         al = SSL3_AD_ILLEGAL_PARAMETER;
 888         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_LENGTH);
 889         goto f_err;
 890     }
 891
 892         /*
 893          * if this is a future (or stale) message it gets buffered
 894          * (or dropped)--no further processing at this time
 895          * While listening, we accept seq 1 (ClientHello with cookie)
 896          * although we're still expecting seq 0 (ClientHello)
 897          */
 898         if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
 899                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 900
 901         if (frag_len && frag_len < len)
 902                 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
 903
 904         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 905                 wire[0] == SSL3_MT_HELLO_REQUEST)
 906                 {
 907                 /* The server may always send 'Hello Request' messages --
 908                  * we are doing a handshake anyway now, so ignore them
 909                  * if their format is correct. Does not count for
 910                  * 'Finished' MAC. */
 911                 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
 912                         {
 913                         if (s->msg_callback)
 914                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 915                                         wire, DTLS1_HM_HEADER_LENGTH, s,
 916                                         s->msg_callback_arg);
 917
 918                         s->init_num = 0;
 919                         goto redo;
 920                         }
 921                 else /* Incorrectly formated Hello request */
 922                         {
 923                         al=SSL_AD_UNEXPECTED_MESSAGE;
 924                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 925                         goto f_err;
 926                         }
 927                 }
 928
 929         if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
 930                 goto f_err;
 931
 932         if ( frag_len > 0)
 933                 {
 934                 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
 935
 936                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 937                         &p[frag_off],frag_len,0);
 938                 /*
 939                  * This shouldn't ever fail due to NBIO because we already checked
 940                  * that we have enough data in the record
 941                  */
 942                 if (i <= 0)
 943                         {
 944                         s->rwstate=SSL_READING;
 945                         *ok = 0;
 946                         return i;
 947                         }
 948                 }
 949         else
 950                 i = 0;
 951
 952         /* XDTLS:  an incorrectly formatted fragment should cause the
 953          * handshake to fail */
 954         if (i != (int)frag_len)
 955                 {
 956                 al=SSL3_AD_ILLEGAL_PARAMETER;
 957                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
 958                 goto f_err;
 959                 }
 960
 961         *ok = 1;
 962     s->state = stn;
 963
 964         /* Note that s->init_num is *not* used as current offset in
 965          * s->init_buf->data, but as a counter summing up fragments'
 966          * lengths: as soon as they sum up to handshake packet
 967          * length, we assume we have got all the fragments. */
 968         s->init_num = frag_len;
 969         return frag_len;
 970
 971 f_err:
 972         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 973         s->init_num = 0;
 974
 975         *ok=0;
 976         return(-1);
 977         }
 978
 979 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
 980         {
 981         unsigned char *p,*d;
 982         int i;
 983         unsigned long l;
 984
 985         if (s->state == a)
 986                 {
 987                 d=(unsigned char *)s->init_buf->data;
 988                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
 989
 990                 i=s->method->ssl3_enc->final_finish_mac(s,
 991                         sender,slen,s->s3->tmp.finish_md);
 992                 s->s3->tmp.finish_md_len = i;
 993                 memcpy(p, s->s3->tmp.finish_md, i);
 994                 p+=i;
 995                 l=i;
 996
 997         /* Copy the finished so we can use it for
 998          * renegotiation checks
 999          */
1000         if(s->type == SSL_ST_CONNECT)
1001                 {
1002                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
1003                 memcpy(s->s3->previous_client_finished,
1004                        s->s3->tmp.finish_md, i);
1005                 s->s3->previous_client_finished_len=i;
1006                 }
1007         else
1008                 {
1009                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
1010                 memcpy(s->s3->previous_server_finished,
1011                        s->s3->tmp.finish_md, i);
1012                 s->s3->previous_server_finished_len=i;
1013                 }
1014
1015 #ifdef OPENSSL_SYS_WIN16
1016                 /* MSVC 1.5 does not clear the top bytes of the word unless
1017                  * I do this.
1018                  */
1019                 l&=0xffff;
1020 #endif
1021
1022                 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
1023                 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
1024                 s->init_off=0;
1025
1026                 /* buffer the message to handle re-xmits */
1027                 dtls1_buffer_message(s, 0);
1028
1029                 s->state=b;
1030                 }
1031
1032         /* SSL3_ST_SEND_xxxxxx_HELLO_B */
1033         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
1034         }
1035
1036 /* for these 2 messages, we need to
1037  * ssl->enc_read_ctx                    re-init
1038  * ssl->s3->read_sequence               zero
1039  * ssl->s3->read_mac_secret             re-init
1040  * ssl->session->read_sym_enc           assign
1041  * ssl->session->read_compression       assign
1042  * ssl->session->read_hash              assign
1043  */
1044 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
1045         {
1046         unsigned char *p;
1047
1048         if (s->state == a)
1049                 {
1050                 p=(unsigned char *)s->init_buf->data;
1051                 *p++=SSL3_MT_CCS;
1052                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1053                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
1054
1055                 if (s->version == DTLS1_BAD_VER) {
1056                         s->d1->next_handshake_write_seq++;
1057                         s2n(s->d1->handshake_write_seq,p);
1058                         s->init_num+=2;
1059                 }
1060
1061                 s->init_off=0;
1062
1063                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1064                         s->d1->handshake_write_seq, 0, 0);
1065
1066                 /* buffer the message to handle re-xmits */
1067                 dtls1_buffer_message(s, 1);
1068
1069                 s->state=b;
1070                 }
1071
1072         /* SSL3_ST_CW_CHANGE_B */
1073         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
1074         }
1075
1076 static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
1077         {
1078         int n;
1079         unsigned char *p;
1080
1081         n=i2d_X509(x,NULL);
1082         if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
1083                 {
1084                 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
1085                 return 0;
1086                 }
1087         p=(unsigned char *)&(buf->data[*l]);
1088         l2n3(n,p);
1089         i2d_X509(x,&p);
1090         *l+=n+3;
1091
1092         return 1;
1093         }
1094 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
1095         {
1096         unsigned char *p;
1097         int i;
1098         unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
1099         BUF_MEM *buf;
1100
1101         /* TLSv1 sends a chain with nothing in it, instead of an alert */
1102         buf=s->init_buf;
1103         if (!BUF_MEM_grow_clean(buf,10))
1104                 {
1105                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
1106                 return(0);
1107                 }
1108         if (x != NULL)
1109                 {
1110                 X509_STORE_CTX xs_ctx;
1111
1112                 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
1113                         {
1114                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
1115                         return(0);
1116                         }
1117
1118                 X509_verify_cert(&xs_ctx);
1119                 /* Don't leave errors in the queue */
1120                 ERR_clear_error();
1121                 for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
1122                         {
1123                         x = sk_X509_value(xs_ctx.chain, i);
1124
1125                         if (!dtls1_add_cert_to_buf(buf, &l, x))
1126                                 {
1127                                 X509_STORE_CTX_cleanup(&xs_ctx);
1128                                 return 0;
1129                                 }
1130                         }
1131                 X509_STORE_CTX_cleanup(&xs_ctx);
1132                 }
1133         /* Thawte special :-) */
1134         for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
1135                 {
1136                 x=sk_X509_value(s->ctx->extra_certs,i);
1137                 if (!dtls1_add_cert_to_buf(buf, &l, x))
1138                         return 0;
1139                 }
1140
1141         l-= (3 + DTLS1_HM_HEADER_LENGTH);
1142
1143         p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1144         l2n3(l,p);
1145         l+=3;
1146         p=(unsigned char *)&(buf->data[0]);
1147         p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1148
1149         l+=DTLS1_HM_HEADER_LENGTH;
1150         return(l);
1151         }
1152
1153 int dtls1_read_failed(SSL *s, int code)
1154         {
1155         if ( code > 0)
1156                 {
1157                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1158                 return 1;
1159                 }
1160
1161         if (!dtls1_is_timer_expired(s))
1162                 {
1163                 /* not a timeout, none of our business,
1164                    let higher layers handle this.  in fact it's probably an error */
1165                 return code;
1166                 }
1167
1168 #ifndef OPENSSL_NO_HEARTBEATS
1169         if (!SSL_in_init(s) && !s->tlsext_hb_pending)  /* done, no need to send a retransmit */
1170 #else
1171         if (!SSL_in_init(s))  /* done, no need to send a retransmit */
1172 #endif
1173                 {
1174                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1175                 return code;
1176                 }
1177
1178 #if 0 /* for now, each alert contains only one record number */
1179         item = pqueue_peek(state->rcvd_records);
1180         if ( item )
1181                 {
1182                 /* send an alert immediately for all the missing records */
1183                 }
1184         else
1185 #endif
1186
1187 #if 0  /* no more alert sending, just retransmit the last set of messages */
1188         if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1189                 ssl3_send_alert(s,SSL3_AL_WARNING,
1190                         DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1191 #endif
1192
1193         return dtls1_handle_timeout(s);
1194         }
1195
1196 int
1197 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1198         {
1199         /* The index of the retransmission queue actually is the message sequence number,
1200          * since the queue only contains messages of a single handshake. However, the
1201          * ChangeCipherSpec has no message sequence number and so using only the sequence
1202          * will result in the CCS and Finished having the same index. To prevent this,
1203          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1204          * This does not only differ CSS and Finished, it also maintains the order of the
1205          * index (important for priority queues) and fits in the unsigned short variable.
1206          */
1207         return seq * 2 - is_ccs;
1208         }
1209
1210 int
1211 dtls1_retransmit_buffered_messages(SSL *s)
1212         {
1213         pqueue sent = s->d1->sent_messages;
1214         piterator iter;
1215         pitem *item;
1216         hm_fragment *frag;
1217         int found = 0;
1218
1219         iter = pqueue_iterator(sent);
1220
1221         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1222                 {
1223                 frag = (hm_fragment *)item->data;
1224                         if ( dtls1_retransmit_message(s,
1225                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1226                                 0, &found) <= 0 && found)
1227                         {
1228                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1229                         return -1;
1230                         }
1231                 }
1232
1233         return 1;
1234         }
1235
1236 int
1237 dtls1_buffer_message(SSL *s, int is_ccs)
1238         {
1239         pitem *item;
1240         hm_fragment *frag;
1241         unsigned char seq64be[8];
1242
1243         /* this function is called immediately after a message has
1244          * been serialized */
1245         OPENSSL_assert(s->init_off == 0);
1246
1247         frag = dtls1_hm_fragment_new(s->init_num, 0);
1248         if (!frag)
1249                 return 0;
1250
1251         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1252
1253         if ( is_ccs)
1254                 {
1255                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1256                                ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num);
1257                 }
1258         else
1259                 {
1260                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1261                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1262                 }
1263
1264         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1265         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1266         frag->msg_header.type = s->d1->w_msg_hdr.type;
1267         frag->msg_header.frag_off = 0;
1268         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1269         frag->msg_header.is_ccs = is_ccs;
1270
1271         /* save current state*/
1272         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1273         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1274         frag->msg_header.saved_retransmit_state.compress = s->compress;
1275         frag->msg_header.saved_retransmit_state.session = s->session;
1276         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1277
1278         memset(seq64be,0,sizeof(seq64be));
1279         seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1280                                                                                                                   frag->msg_header.is_ccs)>>8);
1281         seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1282                                                                                                                   frag->msg_header.is_ccs));
1283
1284         item = pitem_new(seq64be, frag);
1285         if ( item == NULL)
1286                 {
1287                 dtls1_hm_fragment_free(frag);
1288                 return 0;
1289                 }
1290
1291 #if 0
1292         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1293         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1294         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1295 #endif
1296
1297         pqueue_insert(s->d1->sent_messages, item);
1298         return 1;
1299         }
1300
1301 int
1302 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1303         int *found)
1304         {
1305         int ret;
1306         /* XDTLS: for now assuming that read/writes are blocking */
1307         pitem *item;
1308         hm_fragment *frag ;
1309         unsigned long header_length;
1310         unsigned char seq64be[8];
1311         struct dtls1_retransmit_state saved_state;
1312         unsigned char save_write_sequence[8];
1313
1314         /*
1315           OPENSSL_assert(s->init_num == 0);
1316           OPENSSL_assert(s->init_off == 0);
1317          */
1318
1319         /* XDTLS:  the requested message ought to be found, otherwise error */
1320         memset(seq64be,0,sizeof(seq64be));
1321         seq64be[6] = (unsigned char)(seq>>8);
1322         seq64be[7] = (unsigned char)seq;
1323
1324         item = pqueue_find(s->d1->sent_messages, seq64be);
1325         if ( item == NULL)
1326                 {
1327                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1328                 *found = 0;
1329                 return 0;
1330                 }
1331
1332         *found = 1;
1333         frag = (hm_fragment *)item->data;
1334
1335         if ( frag->msg_header.is_ccs)
1336                 header_length = DTLS1_CCS_HEADER_LENGTH;
1337         else
1338                 header_length = DTLS1_HM_HEADER_LENGTH;
1339
1340         memcpy(s->init_buf->data, frag->fragment,
1341                 frag->msg_header.msg_len + header_length);
1342                 s->init_num = frag->msg_header.msg_len + header_length;
1343
1344         dtls1_set_message_header_int(s, frag->msg_header.type,
1345                 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1346                 frag->msg_header.frag_len);
1347
1348         /* save current state */
1349         saved_state.enc_write_ctx = s->enc_write_ctx;
1350         saved_state.write_hash = s->write_hash;
1351         saved_state.compress = s->compress;
1352         saved_state.session = s->session;
1353         saved_state.epoch = s->d1->w_epoch;
1354         saved_state.epoch = s->d1->w_epoch;
1355
1356         s->d1->retransmitting = 1;
1357
1358         /* restore state in which the message was originally sent */
1359         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1360         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1361         s->compress = frag->msg_header.saved_retransmit_state.compress;
1362         s->session = frag->msg_header.saved_retransmit_state.session;
1363         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1364
1365         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1366         {
1367                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1368                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1369         }
1370
1371         ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1372                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1373
1374         /* restore current state */
1375         s->enc_write_ctx = saved_state.enc_write_ctx;
1376         s->write_hash = saved_state.write_hash;
1377         s->compress = saved_state.compress;
1378         s->session = saved_state.session;
1379         s->d1->w_epoch = saved_state.epoch;
1380
1381         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1382         {
1383                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1384                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1385         }
1386
1387         s->d1->retransmitting = 0;
1388
1389         (void)BIO_flush(SSL_get_wbio(s));
1390         return ret;
1391         }
1392
1393 /* call this function when the buffered messages are no longer needed */
1394 void
1395 dtls1_clear_record_buffer(SSL *s)
1396         {
1397         pitem *item;
1398
1399         for(item = pqueue_pop(s->d1->sent_messages);
1400                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1401                 {
1402                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1403                 pitem_free(item);
1404                 }
1405         }
1406
1407
1408 unsigned char *
1409 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1410                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1411         {
1412         /* Don't change sequence numbers while listening */
1413         if (frag_off == 0 && !s->d1->listen)
1414                 {
1415                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1416                 s->d1->next_handshake_write_seq++;
1417                 }
1418
1419         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1420                 frag_off, frag_len);
1421
1422         return p += DTLS1_HM_HEADER_LENGTH;
1423         }
1424
1425
1426 /* don't actually do the writing, wait till the MTU has been retrieved */
1427 static void
1428 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1429                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1430                             unsigned long frag_len)
1431         {
1432         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1433
1434         msg_hdr->type = mt;
1435         msg_hdr->msg_len = len;
1436         msg_hdr->seq = seq_num;
1437         msg_hdr->frag_off = frag_off;
1438         msg_hdr->frag_len = frag_len;
1439         }
1440
1441 static void
1442 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1443                         unsigned long frag_len)
1444         {
1445         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1446
1447         msg_hdr->frag_off = frag_off;
1448         msg_hdr->frag_len = frag_len;
1449         }
1450
1451 static unsigned char *
1452 dtls1_write_message_header(SSL *s, unsigned char *p)
1453         {
1454         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1455
1456         *p++ = msg_hdr->type;
1457         l2n3(msg_hdr->msg_len, p);
1458
1459         s2n(msg_hdr->seq, p);
1460         l2n3(msg_hdr->frag_off, p);
1461         l2n3(msg_hdr->frag_len, p);
1462
1463         return p;
1464         }
1465
1466 unsigned int
1467 dtls1_link_min_mtu(void)
1468         {
1469         return (g_probable_mtu[(sizeof(g_probable_mtu) /
1470                 sizeof(g_probable_mtu[0])) - 1]);
1471         }
1472
1473 unsigned int
1474 dtls1_min_mtu(SSL *s)
1475         {
1476         return dtls1_link_min_mtu()-BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
1477         }
1478
1479
1480 void
1481 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1482         {
1483         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1484         msg_hdr->type = *(data++);
1485         n2l3(data, msg_hdr->msg_len);
1486
1487         n2s(data, msg_hdr->seq);
1488         n2l3(data, msg_hdr->frag_off);
1489         n2l3(data, msg_hdr->frag_len);
1490         }
1491
1492 void
1493 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1494         {
1495         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1496
1497         ccs_hdr->type = *(data++);
1498         }
1499
1500 int dtls1_shutdown(SSL *s)
1501         {
1502         int ret;
1503 #ifndef OPENSSL_NO_SCTP
1504         if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1505             !(s->shutdown & SSL_SENT_SHUTDOWN))
1506                 {
1507                 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
1508                 if (ret < 0) return -1;
1509
1510                 if (ret == 0)
1511                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL);
1512                 }
1513 #endif
1514         ret = ssl3_shutdown(s);
1515 #ifndef OPENSSL_NO_SCTP
1516         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1517 #endif
1518         return ret;
1519         }
1520
1521 #ifndef OPENSSL_NO_HEARTBEATS
1522 int
1523 dtls1_process_heartbeat(SSL *s)
1524         {
1525         unsigned char *p = &s->s3->rrec.data[0], *pl;
1526         unsigned short hbtype;
1527         unsigned int payload;
1528         unsigned int padding = 16; /* Use minimum padding */
1529
1530         if (s->msg_callback)
1531                 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1532                         &s->s3->rrec.data[0], s->s3->rrec.length,
1533                         s, s->msg_callback_arg);
1534
1535         /* Read type and payload length first */
1536         if (1 + 2 + 16 > s->s3->rrec.length)
1537                 return 0; /* silently discard */
1538         if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH)
1539                 return 0; /* silently discard per RFC 6520 sec. 4 */
1540
1541         hbtype = *p++;
1542         n2s(p, payload);
1543         if (1 + 2 + payload + 16 > s->s3->rrec.length)
1544                 return 0; /* silently discard per RFC 6520 sec. 4 */
1545         pl = p;
1546
1547         if (hbtype == TLS1_HB_REQUEST)
1548                 {
1549                 unsigned char *buffer, *bp;
1550                 unsigned int write_length = 1 /* heartbeat type */ +
1551                                             2 /* heartbeat length */ +
1552                                             payload + padding;
1553                 int r;
1554
1555                 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
1556                         return 0;
1557
1558                 /* Allocate memory for the response, size is 1 byte
1559                  * message type, plus 2 bytes payload length, plus
1560                  * payload, plus padding
1561                  */
1562                 buffer = OPENSSL_malloc(write_length);
1563                 bp = buffer;
1564
1565                 /* Enter response type, length and copy payload */
1566                 *bp++ = TLS1_HB_RESPONSE;
1567                 s2n(payload, bp);
1568                 memcpy(bp, pl, payload);
1569                 bp += payload;
1570                 /* Random padding */
1571                 RAND_pseudo_bytes(bp, padding);
1572
1573                 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
1574
1575                 if (r >= 0 && s->msg_callback)
1576                         s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1577                                 buffer, write_length,
1578                                 s, s->msg_callback_arg);
1579
1580                 OPENSSL_free(buffer);
1581
1582                 if (r < 0)
1583                         return r;
1584                 }
1585         else if (hbtype == TLS1_HB_RESPONSE)
1586                 {
1587                 unsigned int seq;
1588
1589                 /* We only send sequence numbers (2 bytes unsigned int),
1590                  * and 16 random bytes, so we just try to read the
1591                  * sequence number */
1592                 n2s(pl, seq);
1593
1594                 if (payload == 18 && seq == s->tlsext_hb_seq)
1595                         {
1596                         dtls1_stop_timer(s);
1597                         s->tlsext_hb_seq++;
1598                         s->tlsext_hb_pending = 0;
1599                         }
1600                 }
1601
1602         return 0;
1603         }
1604
1605 int
1606 dtls1_heartbeat(SSL *s)
1607         {
1608         unsigned char *buf, *p;
1609         int ret;
1610         unsigned int payload = 18; /* Sequence number + random bytes */
1611         unsigned int padding = 16; /* Use minimum padding */
1612
1613         /* Only send if peer supports and accepts HB requests... */
1614         if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1615             s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS)
1616                 {
1617                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1618                 return -1;
1619                 }
1620
1621         /* ...and there is none in flight yet... */
1622         if (s->tlsext_hb_pending)
1623                 {
1624                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING);
1625                 return -1;
1626                 }
1627
1628         /* ...and no handshake in progress. */
1629         if (SSL_in_init(s) || s->in_handshake)
1630                 {
1631                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE);
1632                 return -1;
1633                 }
1634
1635         /* Check if padding is too long, payload and padding
1636          * must not exceed 2^14 - 3 = 16381 bytes in total.
1637          */
1638         OPENSSL_assert(payload + padding <= 16381);
1639
1640         /* Create HeartBeat message, we just use a sequence number
1641          * as payload to distuingish different messages and add
1642          * some random stuff.
1643          *  - Message Type, 1 byte
1644          *  - Payload Length, 2 bytes (unsigned int)
1645          *  - Payload, the sequence number (2 bytes uint)
1646          *  - Payload, random bytes (16 bytes uint)
1647          *  - Padding
1648          */
1649         buf = OPENSSL_malloc(1 + 2 + payload + padding);
1650         p = buf;
1651         /* Message Type */
1652         *p++ = TLS1_HB_REQUEST;
1653         /* Payload length (18 bytes here) */
1654         s2n(payload, p);
1655         /* Sequence number */
1656         s2n(s->tlsext_hb_seq, p);
1657         /* 16 random bytes */
1658         RAND_pseudo_bytes(p, 16);
1659         p += 16;
1660         /* Random padding */
1661         RAND_pseudo_bytes(p, padding);
1662
1663         ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1664         if (ret >= 0)
1665                 {
1666                 if (s->msg_callback)
1667                         s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1668                                 buf, 3 + payload + padding,
1669                                 s, s->msg_callback_arg);
1670
1671                 dtls1_start_timer(s);
1672                 s->tlsext_hb_pending = 1;
1673                 }
1674
1675         OPENSSL_free(buf);
1676
1677         return ret;
1678         }
1679 #endif