ssl/s2_enc.c

   1 /* ssl/s2_enc.c */
   2 /* Copyright (C) 1995-1997 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <stdio.h>
  60 #include "ssl_locl.h"
  61
  62 #define RS      0
  63 #define WS      1
  64
  65 int ssl2_enc_init(s, client)
  66 SSL *s;
  67 int client;
  68         {
  69         /* Max number of bytes needed */
  70         EVP_CIPHER_CTX *rs,*ws;
  71         EVP_CIPHER *c;
  72         EVP_MD *md;
  73         int num;
  74
  75         if (!ssl_cipher_get_evp(s->session->cipher,&c,&md))
  76                 {
  77                 ssl2_return_error(s,SSL2_PE_NO_CIPHER);
  78                 SSLerr(SSL_F_SSL2_ENC_INIT,SSL_R_PROBLEMS_MAPPING_CIPHER_FUNCTIONS);
  79                 return(0);
  80                 }
  81
  82         s->read_hash=md;
  83         s->write_hash=md;
  84
  85         if ((s->enc_read_ctx == NULL) &&
  86                 ((s->enc_read_ctx=(EVP_CIPHER_CTX *)
  87                 Malloc(sizeof(EVP_CIPHER_CTX))) == NULL))
  88                 goto err;
  89         if ((s->enc_write_ctx == NULL) &&
  90                 ((s->enc_write_ctx=(EVP_CIPHER_CTX *)
  91                 Malloc(sizeof(EVP_CIPHER_CTX))) == NULL))
  92                 goto err;
  93
  94         rs= s->enc_read_ctx;
  95         ws= s->enc_write_ctx;
  96
  97         num=c->key_len;
  98         s->s2->key_material_length=num*2;
  99
 100         ssl2_generate_key_material(s);
 101
 102         EVP_EncryptInit(ws,c,&(s->s2->key_material[(client)?num:0]),
 103                 s->session->key_arg);
 104         EVP_DecryptInit(rs,c,&(s->s2->key_material[(client)?0:num]),
 105                 s->session->key_arg);
 106         s->s2->read_key=  &(s->s2->key_material[(client)?0:num]);
 107         s->s2->write_key= &(s->s2->key_material[(client)?num:0]);
 108         return(1);
 109 err:
 110         SSLerr(SSL_F_SSL2_ENC_INIT,ERR_R_MALLOC_FAILURE);
 111         return(0);
 112         }
 113
 114 /* read/writes from s->s2->mac_data using length for encrypt and
 115  * decrypt.  It sets the s->s2->padding, s->[rw]length and
 116  * s->s2->pad_data ptr if we are encrypting */
 117 void ssl2_enc(s,send)
 118 SSL *s;
 119 int send;
 120         {
 121         EVP_CIPHER_CTX *ds;
 122         unsigned long l;
 123         int bs;
 124
 125         if (send)
 126                 {
 127                 ds=s->enc_write_ctx;
 128                 l=s->s2->wlength;
 129                 }
 130         else
 131                 {
 132                 ds=s->enc_read_ctx;
 133                 l=s->s2->rlength;
 134                 }
 135
 136         /* check for NULL cipher */
 137         if (ds == NULL) return;
 138
 139
 140         bs=ds->cipher->block_size;
 141         /* This should be using (bs-1) and bs instead of 7 and 8, but
 142          * what the hell. */
 143         if (bs == 8)
 144                 l=(l+7)/8*8;
 145
 146         EVP_Cipher(ds,s->s2->mac_data,s->s2->mac_data,l);
 147         }
 148
 149 void ssl2_mac(s, md,send)
 150 SSL *s;
 151 unsigned char *md;
 152 int send;
 153         {
 154         EVP_MD_CTX c;
 155         unsigned char sequence[4],*p,*sec,*act;
 156         unsigned long seq;
 157         unsigned int len;
 158
 159         if (send)
 160                 {
 161                 seq=s->s2->write_sequence;
 162                 sec=s->s2->write_key;
 163                 len=s->s2->wact_data_length;
 164                 act=s->s2->wact_data;
 165                 }
 166         else
 167                 {
 168                 seq=s->s2->read_sequence;
 169                 sec=s->s2->read_key;
 170                 len=s->s2->ract_data_length;
 171                 act=s->s2->ract_data;
 172                 }
 173
 174         p= &(sequence[0]);
 175         l2n(seq,p);
 176
 177         /* There has to be a MAC algorithm. */
 178         EVP_DigestInit(&c,s->read_hash);
 179         EVP_DigestUpdate(&c,sec,
 180                 EVP_CIPHER_CTX_key_length(s->enc_read_ctx));
 181         EVP_DigestUpdate(&c,act,len);
 182         /* the above line also does the pad data */
 183         EVP_DigestUpdate(&c,sequence,4);
 184         EVP_DigestFinal(&c,md,NULL);
 185         /* some would say I should zero the md context */
 186         }
 187