crypto/external/bsd/heimdal/dist/lib/gssapi/krb5/8003.c

   1 /*      $NetBSD: 8003.c,v 1.1.1.2 2014/04/24 12:45:29 pettai Exp $      */
   2
   3 /*
   4  * Copyright (c) 1997 - 2003 Kungliga Tekniska Högskolan
   5  * (Royal Institute of Technology, Stockholm, Sweden).
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * 3. Neither the name of the Institute nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include "gsskrb5_locl.h"
  37
  38 krb5_error_code
  39 _gsskrb5_encode_om_uint32(OM_uint32 n, u_char *p)
  40 {
  41   p[0] = (n >> 0)  & 0xFF;
  42   p[1] = (n >> 8)  & 0xFF;
  43   p[2] = (n >> 16) & 0xFF;
  44   p[3] = (n >> 24) & 0xFF;
  45   return 0;
  46 }
  47
  48 krb5_error_code
  49 _gsskrb5_encode_be_om_uint32(OM_uint32 n, u_char *p)
  50 {
  51   p[0] = (n >> 24) & 0xFF;
  52   p[1] = (n >> 16) & 0xFF;
  53   p[2] = (n >> 8)  & 0xFF;
  54   p[3] = (n >> 0)  & 0xFF;
  55   return 0;
  56 }
  57
  58 krb5_error_code
  59 _gsskrb5_decode_om_uint32(const void *ptr, OM_uint32 *n)
  60 {
  61     const u_char *p = ptr;
  62     *n = (p[0] << 0) | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
  63     return 0;
  64 }
  65
  66 krb5_error_code
  67 _gsskrb5_decode_be_om_uint32(const void *ptr, OM_uint32 *n)
  68 {
  69     const u_char *p = ptr;
  70     *n = (p[0] <<24) | (p[1] << 16) | (p[2] << 8) | (p[3] << 0);
  71     return 0;
  72 }
  73
  74 static krb5_error_code
  75 hash_input_chan_bindings (const gss_channel_bindings_t b,
  76                           u_char *p)
  77 {
  78   u_char num[4];
  79   EVP_MD_CTX *ctx;
  80
  81   ctx = EVP_MD_CTX_create();
  82   EVP_DigestInit_ex(ctx, EVP_md5(), NULL);
  83
  84   _gsskrb5_encode_om_uint32 (b->initiator_addrtype, num);
  85   EVP_DigestUpdate(ctx, num, sizeof(num));
  86   _gsskrb5_encode_om_uint32 (b->initiator_address.length, num);
  87   EVP_DigestUpdate(ctx, num, sizeof(num));
  88   if (b->initiator_address.length)
  89       EVP_DigestUpdate(ctx,
  90                        b->initiator_address.value,
  91                        b->initiator_address.length);
  92   _gsskrb5_encode_om_uint32 (b->acceptor_addrtype, num);
  93   EVP_DigestUpdate(ctx, num, sizeof(num));
  94   _gsskrb5_encode_om_uint32 (b->acceptor_address.length, num);
  95   EVP_DigestUpdate(ctx, num, sizeof(num));
  96   if (b->acceptor_address.length)
  97       EVP_DigestUpdate(ctx,
  98                        b->acceptor_address.value,
  99                        b->acceptor_address.length);
 100   _gsskrb5_encode_om_uint32 (b->application_data.length, num);
 101   EVP_DigestUpdate(ctx, num, sizeof(num));
 102   if (b->application_data.length)
 103       EVP_DigestUpdate(ctx,
 104                        b->application_data.value,
 105                        b->application_data.length);
 106   EVP_DigestFinal_ex(ctx, p, NULL);
 107   EVP_MD_CTX_destroy(ctx);
 108
 109   return 0;
 110 }
 111
 112 /*
 113  * create a checksum over the chanel bindings in
 114  * `input_chan_bindings', `flags' and `fwd_data' and return it in
 115  * `result'
 116  */
 117
 118 OM_uint32
 119 _gsskrb5_create_8003_checksum (
 120                       OM_uint32 *minor_status,
 121                       const gss_channel_bindings_t input_chan_bindings,
 122                       OM_uint32 flags,
 123                       const krb5_data *fwd_data,
 124                       Checksum *result)
 125 {
 126     u_char *p;
 127
 128     /*
 129      * see rfc1964 (section 1.1.1 (Initial Token), and the checksum value
 130      * field's format) */
 131     result->cksumtype = CKSUMTYPE_GSSAPI;
 132     if (fwd_data->length > 0 && (flags & GSS_C_DELEG_FLAG))
 133         result->checksum.length = 24 + 4 + fwd_data->length;
 134     else
 135         result->checksum.length = 24;
 136     result->checksum.data   = malloc (result->checksum.length);
 137     if (result->checksum.data == NULL) {
 138         *minor_status = ENOMEM;
 139         return GSS_S_FAILURE;
 140     }
 141
 142     p = result->checksum.data;
 143     _gsskrb5_encode_om_uint32 (16, p);
 144     p += 4;
 145     if (input_chan_bindings == GSS_C_NO_CHANNEL_BINDINGS) {
 146         memset (p, 0, 16);
 147     } else {
 148         hash_input_chan_bindings (input_chan_bindings, p);
 149     }
 150     p += 16;
 151     _gsskrb5_encode_om_uint32 (flags, p);
 152     p += 4;
 153
 154     if (fwd_data->length > 0 && (flags & GSS_C_DELEG_FLAG)) {
 155
 156         *p++ = (1 >> 0) & 0xFF;                   /* DlgOpt */ /* == 1 */
 157         *p++ = (1 >> 8) & 0xFF;                   /* DlgOpt */ /* == 0 */
 158         *p++ = (fwd_data->length >> 0) & 0xFF;    /* Dlgth  */
 159         *p++ = (fwd_data->length >> 8) & 0xFF;    /* Dlgth  */
 160         memcpy(p, (unsigned char *) fwd_data->data, fwd_data->length);
 161
 162         p += fwd_data->length;
 163     }
 164
 165     return GSS_S_COMPLETE;
 166 }
 167
 168 /*
 169  * verify the checksum in `cksum' over `input_chan_bindings'
 170  * returning  `flags' and `fwd_data'
 171  */
 172
 173 OM_uint32
 174 _gsskrb5_verify_8003_checksum(
 175                       OM_uint32 *minor_status,
 176                       const gss_channel_bindings_t input_chan_bindings,
 177                       const Checksum *cksum,
 178                       OM_uint32 *flags,
 179                       krb5_data *fwd_data)
 180 {
 181     unsigned char hash[16];
 182     unsigned char *p;
 183     OM_uint32 length;
 184     int DlgOpt;
 185     static unsigned char zeros[16];
 186
 187     /* XXX should handle checksums > 24 bytes */
 188     if(cksum->cksumtype != CKSUMTYPE_GSSAPI || cksum->checksum.length < 24) {
 189         *minor_status = 0;
 190         return GSS_S_BAD_BINDINGS;
 191     }
 192
 193     p = cksum->checksum.data;
 194     _gsskrb5_decode_om_uint32(p, &length);
 195     if(length != sizeof(hash)) {
 196         *minor_status = 0;
 197         return GSS_S_BAD_BINDINGS;
 198     }
 199
 200     p += 4;
 201
 202     if (input_chan_bindings != GSS_C_NO_CHANNEL_BINDINGS
 203         && memcmp(p, zeros, sizeof(zeros)) != 0) {
 204         if(hash_input_chan_bindings(input_chan_bindings, hash) != 0) {
 205             *minor_status = 0;
 206             return GSS_S_BAD_BINDINGS;
 207         }
 208         if(ct_memcmp(hash, p, sizeof(hash)) != 0) {
 209             *minor_status = 0;
 210             return GSS_S_BAD_BINDINGS;
 211         }
 212     }
 213
 214     p += sizeof(hash);
 215
 216     _gsskrb5_decode_om_uint32(p, flags);
 217     p += 4;
 218
 219     if (cksum->checksum.length > 24 && (*flags & GSS_C_DELEG_FLAG)) {
 220         if(cksum->checksum.length < 28) {
 221             *minor_status = 0;
 222             return GSS_S_BAD_BINDINGS;
 223         }
 224
 225         DlgOpt = (p[0] << 0) | (p[1] << 8);
 226         p += 2;
 227         if (DlgOpt != 1) {
 228             *minor_status = 0;
 229             return GSS_S_BAD_BINDINGS;
 230         }
 231
 232         fwd_data->length = (p[0] << 0) | (p[1] << 8);
 233         p += 2;
 234         if(cksum->checksum.length < 28 + fwd_data->length) {
 235             *minor_status = 0;
 236             return GSS_S_BAD_BINDINGS;
 237         }
 238         fwd_data->data = malloc(fwd_data->length);
 239         if (fwd_data->data == NULL) {
 240             *minor_status = ENOMEM;
 241             return GSS_S_FAILURE;
 242         }
 243         memcpy(fwd_data->data, p, fwd_data->length);
 244     }
 245
 246     return GSS_S_COMPLETE;
 247 }