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 #ifndef OPENSSL_NO_COMP
 119 #include <openssl/comp.h>
 120 #endif
 121 #include <openssl/evp.h>
 122 #include <openssl/hmac.h>
 123 #include <openssl/md5.h>
 124 #include <openssl/rand.h>
 125 #ifdef KSSL_DEBUG
 126 #include <openssl/des.h>
 127 #endif
 128 
 129 /* dtls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively.
 130  *
 131  * Returns:
 132  *   0: (in non-constant time) if the record is publically invalid (i.e. too
 133  *       short etc).
 134  *   1: if the record's padding is valid / the encryption was successful.
 135  *   -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
 136  *       an internal error occured. */
 137 int dtls1_enc(SSL *s, int send)
 138         {
 139         SSL3_RECORD *rec;
 140         EVP_CIPHER_CTX *ds;
 141         unsigned long l;
 142         int bs,i,j,k,mac_size=0;
 143         const EVP_CIPHER *enc;
 144 
 145         if (send)
 146                 {
 147                 if (EVP_MD_CTX_md(s->write_hash))
 148                         {
 149                         mac_size=EVP_MD_CTX_size(s->write_hash);
 150                         if (mac_size < 0)
 151                                 return -1;
 152                         }
 153                 ds=s->enc_write_ctx;
 154                 rec= &(s->s3->wrec);
 155                 if (s->enc_write_ctx == NULL)
 156                         enc=NULL;
 157                 else
 158                         {
 159                         enc=EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
 160                         if ( rec->data != rec->input)
 161                                 /* we can't write into the input stream */
 162                                 fprintf(stderr, "%s:%d: rec->data != rec->input\n",
 163                                         __FILE__, __LINE__);
 164                         else if ( EVP_CIPHER_block_size(ds->cipher) > 1)
 165                                 {
 166                                 if (RAND_bytes(rec->input, EVP_CIPHER_block_size(ds->cipher)) <= 0)
 167                                         return -1;
 168                                 }
 169                         }
 170                 }
 171         else
 172                 {
 173                 if (EVP_MD_CTX_md(s->read_hash))
 174                         {
 175                         mac_size=EVP_MD_CTX_size(s->read_hash);
 176                         OPENSSL_assert(mac_size >= 0);
 177                         }
 178                 ds=s->enc_read_ctx;
 179                 rec= &(s->s3->rrec);
 180                 if (s->enc_read_ctx == NULL)
 181                         enc=NULL;
 182                 else
 183                         enc=EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
 184                 }
 185 
 186 #ifdef KSSL_DEBUG
 187         printf("dtls1_enc(%d)\n", send);
 188 #endif    /* KSSL_DEBUG */
 189 
 190         if ((s->session == NULL) || (ds == NULL) ||
 191                 (enc == NULL))
 192                 {
 193                 memmove(rec->data,rec->input,rec->length);
 194                 rec->input=rec->data;
 195                 }
 196         else
 197                 {
 198                 l=rec->length;
 199                 bs=EVP_CIPHER_block_size(ds->cipher);
 200 
 201                 if ((bs != 1) && send)
 202                         {
 203                         i=bs-((int)l%bs);
 204 
 205                         /* Add weird padding of upto 256 bytes */
 206 
 207                         /* we need to add 'i' padding bytes of value j */
 208                         j=i-1;
 209                         if (s->options & SSL_OP_TLS_BLOCK_PADDING_BUG)
 210                                 {
 211                                 if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG)
 212                                         j++;
 213                                 }
 214                         for (k=(int)l; k<(int)(l+i); k++)
 215                                 rec->input[k]=j;
 216                         l+=i;
 217                         rec->length+=i;
 218                         }
 219 
 220 #ifdef KSSL_DEBUG
 221                 {
 222                 unsigned long ui;
 223                 printf("EVP_Cipher(ds=%p,rec->data=%p,rec->input=%p,l=%ld) ==>\n",
 224                         ds,rec->data,rec->input,l);
 225                 printf("\tEVP_CIPHER_CTX: %d buf_len, %d key_len [%d %d], %d iv_len\n",
 226                         ds->buf_len, ds->cipher->key_len,
 227                         DES_KEY_SZ, DES_SCHEDULE_SZ,
 228                         ds->cipher->iv_len);
 229                 printf("\t\tIV: ");
 230                 for (i=0; i<ds->cipher->iv_len; i++) printf("%02X", ds->iv[i]);
 231                 printf("\n");
 232                 printf("\trec->input=");
 233                 for (ui=0; ui<l; ui++) printf(" %02x", rec->input[ui]);
 234                 printf("\n");
 235                 }
 236 #endif  /* KSSL_DEBUG */
 237 
 238                 if (!send)
 239                         {
 240                         if (l == 0 || l%bs != 0)
 241                                 return 0;
 242                         }
 243 
 244                 EVP_Cipher(ds,rec->data,rec->input,l);
 245 
 246 #ifdef KSSL_DEBUG
 247                 {
 248                 unsigned long i;
 249                 printf("\trec->data=");
 250                 for (i=0; i<l; i++)
 251                         printf(" %02x", rec->data[i]);  printf("\n");
 252                 }
 253 #endif  /* KSSL_DEBUG */
 254 
 255                 if ((bs != 1) && !send)
 256                         return tls1_cbc_remove_padding(s, rec, bs, mac_size);
 257                 }
 258         return(1);
 259         }