lib/gssapi/krb5/get_mic.c

   1 /*
   2  * Copyright (c) 1997, 1998 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed by Kungliga Tekniska
  20  *      Högskolan and its contributors.
  21  *
  22  * 4. Neither the name of the Institute nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  */
  38
  39 #include "gssapi_locl.h"
  40
  41 RCSID("$Id$");
  42
  43 OM_uint32 gss_get_mic
  44            (OM_uint32 * minor_status,
  45             const gss_ctx_id_t context_handle,
  46             gss_qop_t qop_req,
  47             const gss_buffer_t message_buffer,
  48             gss_buffer_t message_token
  49            )
  50 {
  51   u_char *p;
  52   struct md5 md5;
  53   u_char hash[16];
  54   des_key_schedule schedule;
  55   des_cblock key;
  56   des_cblock zero;
  57   int32_t seq_number;
  58   size_t len, total_len;
  59
  60   gssapi_krb5_encap_length (22, &len, &total_len);
  61
  62   message_token->length = total_len;
  63   message_token->value  = malloc (total_len);
  64   if (message_token->value == NULL)
  65     return GSS_S_FAILURE;
  66
  67   p = gssapi_krb5_make_header(message_token->value,
  68                               len,
  69                               "\x01\x01");
  70
  71   memcpy (p, "\x00\x00", 2);
  72   p += 2;
  73   memcpy (p, "\xff\xff\xff\xff", 4);
  74   p += 4;
  75
  76   /* Fill in later */
  77   memset (p, 0, 16);
  78   p += 16;
  79
  80   /* checksum */
  81   md5_init (&md5);
  82   md5_update (&md5, p - 24, 8);
  83   md5_update (&md5, message_buffer->value,
  84               message_buffer->length);
  85   md5_finito (&md5, hash);
  86
  87   memset (&zero, 0, sizeof(zero));
  88   gss_krb5_getsomekey(context_handle, &key);
  89   des_set_key (&key, schedule);
  90   des_cbc_cksum ((des_cblock *)hash,
  91                  (des_cblock *)hash, sizeof(hash), schedule, &zero);
  92   memcpy (p - 8, hash, 8);
  93
  94   /* sequence number */
  95   krb5_auth_getlocalseqnumber (gssapi_krb5_context,
  96                                context_handle->auth_context,
  97                                &seq_number);
  98
  99   p -= 16;
 100   p[0] = (seq_number >> 0)  & 0xFF;
 101   p[1] = (seq_number >> 8)  & 0xFF;
 102   p[2] = (seq_number >> 16) & 0xFF;
 103   p[3] = (seq_number >> 24) & 0xFF;
 104   memset (p + 4,
 105           (context_handle->more_flags & LOCAL) ? 0 : 0xFF,
 106           4);
 107
 108   des_set_key (&key, schedule);
 109   des_cbc_encrypt ((des_cblock *)p, (des_cblock *)p, 8,
 110                    schedule, (des_cblock *)(p + 8), DES_ENCRYPT);
 111
 112   krb5_auth_setlocalseqnumber (gssapi_krb5_context,
 113                                context_handle->auth_context,
 114                                ++seq_number);
 115
 116   memset (key, 0, sizeof(key));
 117   memset (schedule, 0, sizeof(schedule));
 118
 119   return GSS_S_COMPLETE;
 120 }