1: /* ssl/s2_enc.c */
    2: /* Copyright (C) 1995-1998 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 "ssl_locl.h"
   60: #ifndef OPENSSL_NO_SSL2
   61: #include <stdio.h>
   62: 
   63: int ssl2_enc_init(SSL *s, int client)
   64:         {
   65:         /* Max number of bytes needed */
   66:         EVP_CIPHER_CTX *rs,*ws;
   67:         const EVP_CIPHER *c;
   68:         const EVP_MD *md;
   69:         int num;
   70: 
   71:         if (!ssl_cipher_get_evp(s->session,&c,&md,NULL))
   72:                 {
   73:                 ssl2_return_error(s,SSL2_PE_NO_CIPHER);
   74:                 SSLerr(SSL_F_SSL2_ENC_INIT,SSL_R_PROBLEMS_MAPPING_CIPHER_FUNCTIONS);
   75:                 return(0);
   76:                 }
   77: 
   78:         s->read_hash=md;
   79:         s->write_hash=md;
   80: 
   81:         if ((s->enc_read_ctx == NULL) &&
   82:                 ((s->enc_read_ctx=(EVP_CIPHER_CTX *)
   83:                 OPENSSL_malloc(sizeof(EVP_CIPHER_CTX))) == NULL))
   84:                 goto err;
   85: 
   86:         /* make sure it's intialized in case the malloc for enc_write_ctx fails
   87:          * and we exit with an error */
   88:         rs= s->enc_read_ctx;
   89:         EVP_CIPHER_CTX_init(rs);
   90: 
   91:         if ((s->enc_write_ctx == NULL) &&
   92:                 ((s->enc_write_ctx=(EVP_CIPHER_CTX *)
   93:                 OPENSSL_malloc(sizeof(EVP_CIPHER_CTX))) == NULL))
   94:                 goto err;
   95: 
   96:         ws= s->enc_write_ctx;
   97:         EVP_CIPHER_CTX_init(ws);
   98: 
   99:         num=c->key_len;
  100:         s->s2->key_material_length=num*2;
  101:         OPENSSL_assert(s->s2->key_material_length <= sizeof s->s2->key_material);
  102: 
  103:         if (ssl2_generate_key_material(s) <= 0)
  104:                 return 0;
  105: 
  106:         OPENSSL_assert(c->iv_len <= (int)sizeof(s->session->key_arg));
  107:         EVP_EncryptInit_ex(ws,c,NULL,&(s->s2->key_material[(client)?num:0]),
  108:                 s->session->key_arg);
  109:         EVP_DecryptInit_ex(rs,c,NULL,&(s->s2->key_material[(client)?0:num]),
  110:                 s->session->key_arg);
  111:         s->s2->read_key=  &(s->s2->key_material[(client)?0:num]);
  112:         s->s2->write_key= &(s->s2->key_material[(client)?num:0]);
  113:         return(1);
  114: err:
  115:         SSLerr(SSL_F_SSL2_ENC_INIT,ERR_R_MALLOC_FAILURE);
  116:         return(0);
  117:         }
  118: 
  119: /* read/writes from s->s2->mac_data using length for encrypt and 
  120:  * decrypt.  It sets s->s2->padding and s->[rw]length
  121:  * if we are encrypting */
  122: void ssl2_enc(SSL *s, int send)
  123:         {
  124:         EVP_CIPHER_CTX *ds;
  125:         unsigned long l;
  126:         int bs;
  127: 
  128:         if (send)
  129:                 {
  130:                 ds=s->enc_write_ctx;
  131:                 l=s->s2->wlength;
  132:                 }
  133:         else
  134:                 {
  135:                 ds=s->enc_read_ctx;
  136:                 l=s->s2->rlength;
  137:                 }
  138: 
  139:         /* check for NULL cipher */
  140:         if (ds == NULL) return;
  141: 
  142: 
  143:         bs=ds->cipher->block_size;
  144:         /* This should be using (bs-1) and bs instead of 7 and 8, but
  145:          * what the hell. */
  146:         if (bs == 8)
  147:                 l=(l+7)/8*8;
  148: 
  149:         EVP_Cipher(ds,s->s2->mac_data,s->s2->mac_data,l);
  150:         }
  151: 
  152: void ssl2_mac(SSL *s, unsigned char *md, 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_MD_CTX_init(&c);
  179:         EVP_DigestInit_ex(&c, s->read_hash, NULL);
  180:         EVP_DigestUpdate(&c,sec,
  181:                 EVP_CIPHER_CTX_key_length(s->enc_read_ctx));
  182:         EVP_DigestUpdate(&c,act,len); 
  183:         /* the above line also does the pad data */
  184:         EVP_DigestUpdate(&c,sequence,4); 
  185:         EVP_DigestFinal_ex(&c,md,NULL);
  186:         EVP_MD_CTX_cleanup(&c);
  187:         }
  188: #else /* !OPENSSL_NO_SSL2 */
  189: 
  190: # if PEDANTIC
  191: static void *dummy=&dummy;
  192: # endif
  193: 
  194: #endif