lib/gssapi/krb5/8003.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 static krb5_error_code
  44 encode_om_uint32(OM_uint32 n, u_char *p)
  45 {
  46   p[0] = (n >> 0)  & 0xFF;
  47   p[1] = (n >> 8)  & 0xFF;
  48   p[2] = (n >> 16) & 0xFF;
  49   p[3] = (n >> 24) & 0xFF;
  50   return 0;
  51 }
  52
  53 static krb5_error_code
  54 decode_om_uint32(u_char *p, OM_uint32 *n)
  55 {
  56     *n = (p[0] << 0) | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
  57     return 0;
  58 }
  59
  60 static krb5_error_code
  61 hash_input_chan_bindings (const gss_channel_bindings_t b,
  62                           u_char *p)
  63 {
  64   u_char num[4];
  65   struct md5 md5;
  66
  67   md5_init(&md5);
  68   encode_om_uint32 (b->initiator_addrtype, num);
  69   md5_update (&md5, num, sizeof(num));
  70   encode_om_uint32 (b->initiator_address.length, num);
  71   md5_update (&md5, num, sizeof(num));
  72   if (b->initiator_address.length)
  73     md5_update (&md5,
  74                 b->initiator_address.value,
  75                 b->initiator_address.length);
  76   encode_om_uint32 (b->acceptor_addrtype, num);
  77   md5_update (&md5, num, sizeof(num));
  78   encode_om_uint32 (b->acceptor_address.length, num);
  79   md5_update (&md5, num, sizeof(num));
  80   if (b->acceptor_address.length)
  81     md5_update (&md5,
  82                 b->acceptor_address.value,
  83                 b->acceptor_address.length);
  84   encode_om_uint32 (b->application_data.length, num);
  85   md5_update (&md5, num, sizeof(num));
  86   if (b->application_data.length)
  87     md5_update (&md5,
  88                 b->application_data.value,
  89                 b->application_data.length);
  90   md5_finito (&md5, p);
  91   return 0;
  92 }
  93
  94 krb5_error_code
  95 gssapi_krb5_create_8003_checksum (
  96                       const gss_channel_bindings_t input_chan_bindings,
  97                       OM_uint32 flags,
  98                       Checksum *result)
  99 {
 100   u_char *p;
 101
 102   result->cksumtype = 0x8003;
 103   result->checksum.length = 24;
 104   result->checksum.data   = malloc (result->checksum.length);
 105   if (result->checksum.data == NULL)
 106     return ENOMEM;
 107
 108   p = result->checksum.data;
 109   encode_om_uint32 (16, p);
 110   p += 4;
 111   if (input_chan_bindings == GSS_C_NO_CHANNEL_BINDINGS) {
 112     memset (p, 0, 16);
 113   } else {
 114     hash_input_chan_bindings (input_chan_bindings, p);
 115   }
 116   p += 16;
 117   encode_om_uint32 (flags, p);
 118   p += 4;
 119   if (p - (u_char *)result->checksum.data != result->checksum.length)
 120     abort ();
 121   return 0;
 122 }
 123
 124 krb5_error_code
 125 gssapi_krb5_verify_8003_checksum(
 126                       const gss_channel_bindings_t input_chan_bindings,
 127                       Checksum *cksum,
 128                       OM_uint32 *flags)
 129 {
 130     unsigned char hash[16];
 131     unsigned char *p;
 132     OM_uint32 length;
 133
 134     /* XXX should handle checksums > 24 bytes */
 135     if(cksum->cksumtype != 0x8003 || cksum->checksum.length != 24)
 136         return GSS_S_BAD_BINDINGS;
 137
 138     p = cksum->checksum.data;
 139     decode_om_uint32(p, &length);
 140     if(length != sizeof(hash))
 141         return GSS_S_FAILURE;
 142
 143     p += 4;
 144
 145     if (input_chan_bindings != GSS_C_NO_CHANNEL_BINDINGS) {
 146         if(hash_input_chan_bindings(input_chan_bindings, hash) != 0)
 147             return GSS_S_FAILURE;
 148         if(memcmp(hash, p, sizeof(hash)) != 0)
 149             return GSS_S_FAILURE;
 150     }
 151
 152     p += sizeof(hash);
 153
 154     decode_om_uint32(p, flags);
 155
 156     return 0;
 157 }