ssl/d1_enc.c

   1 /* ssl/d1_enc.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 <stdio.h>
 117 #include "ssl_locl.h"
 118 #include <openssl/comp.h>
 119 #include <openssl/evp.h>
 120 #include <openssl/hmac.h>
 121 #include <openssl/md5.h>
 122 #include <openssl/rand.h>
 123 #ifdef KSSL_DEBUG
 124 #include <openssl/des.h>
 125 #endif
 126
 127 int dtls1_enc(SSL *s, int send)
 128         {
 129         SSL3_RECORD *rec;
 130         EVP_CIPHER_CTX *ds;
 131         unsigned long l;
 132         int bs,i,ii,j,k,n=0;
 133         const EVP_CIPHER *enc;
 134
 135         if (send)
 136                 {
 137                 if (EVP_MD_CTX_md(s->write_hash))
 138                         n=EVP_MD_CTX_size(s->write_hash);
 139                 ds=s->enc_write_ctx;
 140                 rec= &(s->s3->wrec);
 141                 if (s->enc_write_ctx == NULL)
 142                         enc=NULL;
 143                 else
 144                         {
 145                         enc=EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
 146                         if ( rec->data != rec->input)
 147                                 /* we can't write into the input stream */
 148                                 fprintf(stderr, "%s:%d: rec->data != rec->input\n",
 149                                         __FILE__, __LINE__);
 150                         else if ( EVP_CIPHER_block_size(ds->cipher) > 1)
 151                                 {
 152                                 if (!RAND_bytes(rec->input, EVP_CIPHER_block_size(ds->cipher)))
 153                                         return -1;
 154                                 }
 155                         }
 156                 }
 157         else
 158                 {
 159                 if (EVP_MD_CTX_md(s->read_hash))
 160                         n=EVP_MD_CTX_size(s->read_hash);
 161                 ds=s->enc_read_ctx;
 162                 rec= &(s->s3->rrec);
 163                 if (s->enc_read_ctx == NULL)
 164                         enc=NULL;
 165                 else
 166                         enc=EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
 167                 }
 168
 169 #ifdef KSSL_DEBUG
 170         printf("dtls1_enc(%d)\n", send);
 171 #endif    /* KSSL_DEBUG */
 172
 173         if ((s->session == NULL) || (ds == NULL) ||
 174                 (enc == NULL))
 175                 {
 176                 memmove(rec->data,rec->input,rec->length);
 177                 rec->input=rec->data;
 178                 }
 179         else
 180                 {
 181                 l=rec->length;
 182                 bs=EVP_CIPHER_block_size(ds->cipher);
 183
 184                 if ((bs != 1) && send)
 185                         {
 186                         i=bs-((int)l%bs);
 187
 188                         /* Add weird padding of upto 256 bytes */
 189
 190                         /* we need to add 'i' padding bytes of value j */
 191                         j=i-1;
 192                         if (s->options & SSL_OP_TLS_BLOCK_PADDING_BUG)
 193                                 {
 194                                 if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG)
 195                                         j++;
 196                                 }
 197                         for (k=(int)l; k<(int)(l+i); k++)
 198                                 rec->input[k]=j;
 199                         l+=i;
 200                         rec->length+=i;
 201                         }
 202
 203 #ifdef KSSL_DEBUG
 204                 {
 205                 unsigned long ui;
 206                 printf("EVP_Cipher(ds=%p,rec->data=%p,rec->input=%p,l=%ld) ==>\n",
 207                         ds,rec->data,rec->input,l);
 208                 printf("\tEVP_CIPHER_CTX: %d buf_len, %d key_len [%d %d], %d iv_len\n",
 209                         ds->buf_len, ds->cipher->key_len,
 210                         DES_KEY_SZ, DES_SCHEDULE_SZ,
 211                         ds->cipher->iv_len);
 212                 printf("\t\tIV: ");
 213                 for (i=0; i<ds->cipher->iv_len; i++) printf("%02X", ds->iv[i]);
 214                 printf("\n");
 215                 printf("\trec->input=");
 216                 for (ui=0; ui<l; ui++) printf(" %02x", rec->input[ui]);
 217                 printf("\n");
 218                 }
 219 #endif  /* KSSL_DEBUG */
 220
 221                 if (!send)
 222                         {
 223                         if (l == 0 || l%bs != 0)
 224                                 {
 225                                 SSLerr(SSL_F_DTLS1_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
 226                                 ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPTION_FAILED);
 227                                 return 0;
 228                                 }
 229                         }
 230
 231                 EVP_Cipher(ds,rec->data,rec->input,l);
 232
 233 #ifdef KSSL_DEBUG
 234                 {
 235                 unsigned long i;
 236                 printf("\trec->data=");
 237                 for (i=0; i<l; i++)
 238                         printf(" %02x", rec->data[i]);  printf("\n");
 239                 }
 240 #endif  /* KSSL_DEBUG */
 241
 242                 if ((bs != 1) && !send)
 243                         {
 244                         ii=i=rec->data[l-1]; /* padding_length */
 245                         i++;
 246                         if (s->options&SSL_OP_TLS_BLOCK_PADDING_BUG)
 247                                 {
 248                                 /* First packet is even in size, so check */
 249                                 if ((memcmp(s->s3->read_sequence,
 250                                         "\0\0\0\0\0\0\0\0",8) == 0) && !(ii & 1))
 251                                         s->s3->flags|=TLS1_FLAGS_TLS_PADDING_BUG;
 252                                 if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG)
 253                                         i--;
 254                                 }
 255                         /* TLS 1.0 does not bound the number of padding bytes by the block size.
 256                          * All of them must have value 'padding_length'. */
 257                         if (i > (int)rec->length)
 258                                 {
 259                                 /* Incorrect padding. SSLerr() and ssl3_alert are done
 260                                  * by caller: we don't want to reveal whether this is
 261                                  * a decryption error or a MAC verification failure
 262                                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
 263                                  */
 264                                 return -1;
 265                                 }
 266                         for (j=(int)(l-i); j<(int)l; j++)
 267                                 {
 268                                 if (rec->data[j] != ii)
 269                                         {
 270                                         /* Incorrect padding */
 271                                         return -1;
 272                                         }
 273                                 }
 274                         rec->length-=i;
 275
 276                         rec->data += bs;    /* skip the implicit IV */
 277                         rec->input += bs;
 278                         rec->length -= bs;
 279                         }
 280                 }
 281         return(1);
 282         }
 283