lib/gssapi/get_mic.c

   1 /*
   2  * Copyright (c) 1997 - 2003 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. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "gssapi_locl.h"
  35
  36 RCSID("$Id$");
  37
  38 static OM_uint32
  39 mic_des
  40            (OM_uint32 * minor_status,
  41             const gss_ctx_id_t context_handle,
  42             gss_qop_t qop_req,
  43             const gss_buffer_t message_buffer,
  44             gss_buffer_t message_token,
  45             krb5_keyblock *key
  46            )
  47 {
  48   u_char *p;
  49   MD5_CTX md5;
  50   u_char hash[16];
  51   DES_key_schedule schedule;
  52   DES_cblock deskey;
  53   DES_cblock zero;
  54   int32_t seq_number;
  55   size_t len, total_len;
  56
  57   gssapi_krb5_encap_length (22, &len, &total_len, GSS_KRB5_MECHANISM);
  58
  59   message_token->length = total_len;
  60   message_token->value  = malloc (total_len);
  61   if (message_token->value == NULL) {
  62     *minor_status = ENOMEM;
  63     return GSS_S_FAILURE;
  64   }
  65
  66   p = gssapi_krb5_make_header(message_token->value,
  67                               len,
  68                               "\x01\x01", /* TOK_ID */
  69                               GSS_KRB5_MECHANISM);
  70
  71   memcpy (p, "\x00\x00", 2);    /* SGN_ALG = DES MAC MD5 */
  72   p += 2;
  73
  74   memcpy (p, "\xff\xff\xff\xff", 4); /* Filler */
  75   p += 4;
  76
  77   /* Fill in later (SND-SEQ) */
  78   memset (p, 0, 16);
  79   p += 16;
  80
  81   /* checksum */
  82   MD5_Init (&md5);
  83   MD5_Update (&md5, p - 24, 8);
  84   MD5_Update (&md5, message_buffer->value, message_buffer->length);
  85   MD5_Final (hash, &md5);
  86
  87   memset (&zero, 0, sizeof(zero));
  88   memcpy (&deskey, key->keyvalue.data, sizeof(deskey));
  89   DES_set_key (&deskey, &schedule);
  90   DES_cbc_cksum ((void *)hash, (void *)hash, sizeof(hash),
  91                  &schedule, &zero);
  92   memcpy (p - 8, hash, 8);      /* SGN_CKSUM */
  93
  94   HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
  95   /* sequence number */
  96   krb5_auth_con_getlocalseqnumber (gssapi_krb5_context,
  97                                context_handle->auth_context,
  98                                &seq_number);
  99
 100   p -= 16;                      /* SND_SEQ */
 101   p[0] = (seq_number >> 0)  & 0xFF;
 102   p[1] = (seq_number >> 8)  & 0xFF;
 103   p[2] = (seq_number >> 16) & 0xFF;
 104   p[3] = (seq_number >> 24) & 0xFF;
 105   memset (p + 4,
 106           (context_handle->more_flags & LOCAL) ? 0 : 0xFF,
 107           4);
 108
 109   DES_set_key (&deskey, &schedule);
 110   DES_cbc_encrypt ((void *)p, (void *)p, 8,
 111                    &schedule, (DES_cblock *)(p + 8), DES_ENCRYPT);
 112
 113   krb5_auth_con_setlocalseqnumber (gssapi_krb5_context,
 114                                context_handle->auth_context,
 115                                ++seq_number);
 116   HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
 117
 118   memset (deskey, 0, sizeof(deskey));
 119   memset (&schedule, 0, sizeof(schedule));
 120
 121   *minor_status = 0;
 122   return GSS_S_COMPLETE;
 123 }
 124
 125 static OM_uint32
 126 mic_des3
 127            (OM_uint32 * minor_status,
 128             const gss_ctx_id_t context_handle,
 129             gss_qop_t qop_req,
 130             const gss_buffer_t message_buffer,
 131             gss_buffer_t message_token,
 132             krb5_keyblock *key
 133            )
 134 {
 135   u_char *p;
 136   Checksum cksum;
 137   u_char seq[8];
 138
 139   int32_t seq_number;
 140   size_t len, total_len;
 141
 142   krb5_crypto crypto;
 143   krb5_error_code kret;
 144   krb5_data encdata;
 145   char *tmp;
 146   char ivec[8];
 147
 148   gssapi_krb5_encap_length (36, &len, &total_len, GSS_KRB5_MECHANISM);
 149
 150   message_token->length = total_len;
 151   message_token->value  = malloc (total_len);
 152   if (message_token->value == NULL) {
 153       *minor_status = ENOMEM;
 154       return GSS_S_FAILURE;
 155   }
 156
 157   p = gssapi_krb5_make_header(message_token->value,
 158                               len,
 159                               "\x01\x01", /* TOK-ID */
 160                               GSS_KRB5_MECHANISM);
 161
 162   memcpy (p, "\x04\x00", 2);    /* SGN_ALG = HMAC SHA1 DES3-KD */
 163   p += 2;
 164
 165   memcpy (p, "\xff\xff\xff\xff", 4); /* filler */
 166   p += 4;
 167
 168   /* this should be done in parts */
 169
 170   tmp = malloc (message_buffer->length + 8);
 171   if (tmp == NULL) {
 172       free (message_token->value);
 173       *minor_status = ENOMEM;
 174       return GSS_S_FAILURE;
 175   }
 176   memcpy (tmp, p - 8, 8);
 177   memcpy (tmp + 8, message_buffer->value, message_buffer->length);
 178
 179   kret = krb5_crypto_init(gssapi_krb5_context, key, 0, &crypto);
 180   if (kret) {
 181       free (message_token->value);
 182       free (tmp);
 183       gssapi_krb5_set_error_string ();
 184       *minor_status = kret;
 185       return GSS_S_FAILURE;
 186   }
 187
 188   kret = krb5_create_checksum (gssapi_krb5_context,
 189                                crypto,
 190                                KRB5_KU_USAGE_SIGN,
 191                                0,
 192                                tmp,
 193                                message_buffer->length + 8,
 194                                &cksum);
 195   free (tmp);
 196   krb5_crypto_destroy (gssapi_krb5_context, crypto);
 197   if (kret) {
 198       free (message_token->value);
 199       gssapi_krb5_set_error_string ();
 200       *minor_status = kret;
 201       return GSS_S_FAILURE;
 202   }
 203
 204   memcpy (p + 8, cksum.checksum.data, cksum.checksum.length);
 205
 206   HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
 207   /* sequence number */
 208   krb5_auth_con_getlocalseqnumber (gssapi_krb5_context,
 209                                context_handle->auth_context,
 210                                &seq_number);
 211
 212   seq[0] = (seq_number >> 0)  & 0xFF;
 213   seq[1] = (seq_number >> 8)  & 0xFF;
 214   seq[2] = (seq_number >> 16) & 0xFF;
 215   seq[3] = (seq_number >> 24) & 0xFF;
 216   memset (seq + 4,
 217           (context_handle->more_flags & LOCAL) ? 0 : 0xFF,
 218           4);
 219
 220   kret = krb5_crypto_init(gssapi_krb5_context, key,
 221                           ETYPE_DES3_CBC_NONE, &crypto);
 222   if (kret) {
 223       free (message_token->value);
 224       gssapi_krb5_set_error_string ();
 225       *minor_status = kret;
 226       return GSS_S_FAILURE;
 227   }
 228
 229   if (context_handle->more_flags & COMPAT_OLD_DES3)
 230       memset(ivec, 0, 8);
 231   else
 232       memcpy(ivec, p + 8, 8);
 233
 234   kret = krb5_encrypt_ivec (gssapi_krb5_context,
 235                             crypto,
 236                             KRB5_KU_USAGE_SEQ,
 237                             seq, 8, &encdata, ivec);
 238   krb5_crypto_destroy (gssapi_krb5_context, crypto);
 239   if (kret) {
 240       free (message_token->value);
 241       gssapi_krb5_set_error_string ();
 242       *minor_status = kret;
 243       return GSS_S_FAILURE;
 244   }
 245
 246   assert (encdata.length == 8);
 247
 248   memcpy (p, encdata.data, encdata.length);
 249   krb5_data_free (&encdata);
 250
 251   krb5_auth_con_setlocalseqnumber (gssapi_krb5_context,
 252                                context_handle->auth_context,
 253                                ++seq_number);
 254   HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
 255
 256   free_Checksum (&cksum);
 257   *minor_status = 0;
 258   return GSS_S_COMPLETE;
 259 }
 260
 261 OM_uint32 gss_get_mic
 262            (OM_uint32 * minor_status,
 263             const gss_ctx_id_t context_handle,
 264             gss_qop_t qop_req,
 265             const gss_buffer_t message_buffer,
 266             gss_buffer_t message_token
 267            )
 268 {
 269   krb5_keyblock *key;
 270   OM_uint32 ret;
 271   krb5_keytype keytype;
 272
 273   ret = gss_krb5_get_subkey(context_handle, &key);
 274   if (ret) {
 275       gssapi_krb5_set_error_string ();
 276       *minor_status = ret;
 277       return GSS_S_FAILURE;
 278   }
 279   krb5_enctype_to_keytype (gssapi_krb5_context, key->keytype, &keytype);
 280
 281   switch (keytype) {
 282   case KEYTYPE_DES :
 283       ret = mic_des (minor_status, context_handle, qop_req,
 284                      message_buffer, message_token, key);
 285       break;
 286   case KEYTYPE_DES3 :
 287       ret = mic_des3 (minor_status, context_handle, qop_req,
 288                       message_buffer, message_token, key);
 289       break;
 290   case KEYTYPE_ARCFOUR:
 291       ret = _gssapi_get_mic_arcfour (minor_status, context_handle, qop_req,
 292                                      message_buffer, message_token, key);
 293       break;
 294   default :
 295       ret = _gssapi_mic_cfx (minor_status, context_handle, qop_req,
 296                              message_buffer, message_token, key);
 297       break;
 298   }
 299   krb5_free_keyblock (gssapi_krb5_context, key);
 300   return ret;
 301 }