lib/gssapi/krb5/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 "gsskrb5_locl.h"
  35
  36 static OM_uint32
  37 mic_des
  38            (OM_uint32 * minor_status,
  39             const gsskrb5_ctx ctx,
  40             krb5_context context,
  41             gss_qop_t qop_req,
  42             const gss_buffer_t message_buffer,
  43             gss_buffer_t message_token,
  44             krb5_keyblock *key
  45            )
  46 {
  47   u_char *p;
  48   MD5_CTX md5;
  49   u_char hash[16];
  50   DES_key_schedule schedule;
  51   DES_cblock deskey;
  52   DES_cblock zero;
  53   int32_t seq_number;
  54   size_t len, total_len;
  55
  56   _gsskrb5_encap_length (22, &len, &total_len, GSS_KRB5_MECHANISM);
  57
  58   message_token->length = total_len;
  59   message_token->value  = malloc (total_len);
  60   if (message_token->value == NULL) {
  61     message_token->length = 0;
  62     *minor_status = ENOMEM;
  63     return GSS_S_FAILURE;
  64   }
  65
  66   p = _gsskrb5_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_unchecked (&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(&ctx->ctx_id_mutex);
  95   /* sequence number */
  96   krb5_auth_con_getlocalseqnumber (context,
  97                                    ctx->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           (ctx->more_flags & LOCAL) ? 0 : 0xFF,
 107           4);
 108
 109   DES_set_key_unchecked (&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 (context,
 114                                ctx->auth_context,
 115                                ++seq_number);
 116   HEIMDAL_MUTEX_unlock(&ctx->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 gsskrb5_ctx ctx,
 129             krb5_context context,
 130             gss_qop_t qop_req,
 131             const gss_buffer_t message_buffer,
 132             gss_buffer_t message_token,
 133             krb5_keyblock *key
 134            )
 135 {
 136   u_char *p;
 137   Checksum cksum;
 138   u_char seq[8];
 139
 140   int32_t seq_number;
 141   size_t len, total_len;
 142
 143   krb5_crypto crypto;
 144   krb5_error_code kret;
 145   krb5_data encdata;
 146   char *tmp;
 147   char ivec[8];
 148
 149   _gsskrb5_encap_length (36, &len, &total_len, GSS_KRB5_MECHANISM);
 150
 151   message_token->length = total_len;
 152   message_token->value  = malloc (total_len);
 153   if (message_token->value == NULL) {
 154       message_token->length = 0;
 155       *minor_status = ENOMEM;
 156       return GSS_S_FAILURE;
 157   }
 158
 159   p = _gsskrb5_make_header(message_token->value,
 160                               len,
 161                               "\x01\x01", /* TOK-ID */
 162                               GSS_KRB5_MECHANISM);
 163
 164   memcpy (p, "\x04\x00", 2);    /* SGN_ALG = HMAC SHA1 DES3-KD */
 165   p += 2;
 166
 167   memcpy (p, "\xff\xff\xff\xff", 4); /* filler */
 168   p += 4;
 169
 170   /* this should be done in parts */
 171
 172   tmp = malloc (message_buffer->length + 8);
 173   if (tmp == NULL) {
 174       free (message_token->value);
 175       message_token->value = NULL;
 176       message_token->length = 0;
 177       *minor_status = ENOMEM;
 178       return GSS_S_FAILURE;
 179   }
 180   memcpy (tmp, p - 8, 8);
 181   memcpy (tmp + 8, message_buffer->value, message_buffer->length);
 182
 183   kret = krb5_crypto_init(context, key, 0, &crypto);
 184   if (kret) {
 185       free (message_token->value);
 186       message_token->value = NULL;
 187       message_token->length = 0;
 188       free (tmp);
 189       *minor_status = kret;
 190       return GSS_S_FAILURE;
 191   }
 192
 193   kret = krb5_create_checksum (context,
 194                                crypto,
 195                                KRB5_KU_USAGE_SIGN,
 196                                0,
 197                                tmp,
 198                                message_buffer->length + 8,
 199                                &cksum);
 200   free (tmp);
 201   krb5_crypto_destroy (context, crypto);
 202   if (kret) {
 203       free (message_token->value);
 204       message_token->value = NULL;
 205       message_token->length = 0;
 206       *minor_status = kret;
 207       return GSS_S_FAILURE;
 208   }
 209
 210   memcpy (p + 8, cksum.checksum.data, cksum.checksum.length);
 211
 212   HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
 213   /* sequence number */
 214   krb5_auth_con_getlocalseqnumber (context,
 215                                ctx->auth_context,
 216                                &seq_number);
 217
 218   seq[0] = (seq_number >> 0)  & 0xFF;
 219   seq[1] = (seq_number >> 8)  & 0xFF;
 220   seq[2] = (seq_number >> 16) & 0xFF;
 221   seq[3] = (seq_number >> 24) & 0xFF;
 222   memset (seq + 4,
 223           (ctx->more_flags & LOCAL) ? 0 : 0xFF,
 224           4);
 225
 226   kret = krb5_crypto_init(context, key,
 227                           ETYPE_DES3_CBC_NONE, &crypto);
 228   if (kret) {
 229       free (message_token->value);
 230       message_token->value = NULL;
 231       message_token->length = 0;
 232       *minor_status = kret;
 233       return GSS_S_FAILURE;
 234   }
 235
 236   if (ctx->more_flags & COMPAT_OLD_DES3)
 237       memset(ivec, 0, 8);
 238   else
 239       memcpy(ivec, p + 8, 8);
 240
 241   kret = krb5_encrypt_ivec (context,
 242                             crypto,
 243                             KRB5_KU_USAGE_SEQ,
 244                             seq, 8, &encdata, ivec);
 245   krb5_crypto_destroy (context, crypto);
 246   if (kret) {
 247       free (message_token->value);
 248       message_token->value = NULL;
 249       message_token->length = 0;
 250       *minor_status = kret;
 251       return GSS_S_FAILURE;
 252   }
 253
 254   assert (encdata.length == 8);
 255
 256   memcpy (p, encdata.data, encdata.length);
 257   krb5_data_free (&encdata);
 258
 259   krb5_auth_con_setlocalseqnumber (context,
 260                                ctx->auth_context,
 261                                ++seq_number);
 262   HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
 263
 264   free_Checksum (&cksum);
 265   *minor_status = 0;
 266   return GSS_S_COMPLETE;
 267 }
 268
 269 OM_uint32 _gsskrb5_get_mic
 270            (OM_uint32 * minor_status,
 271             const gss_ctx_id_t context_handle,
 272             gss_qop_t qop_req,
 273             const gss_buffer_t message_buffer,
 274             gss_buffer_t message_token
 275            )
 276 {
 277   krb5_context context;
 278   const gsskrb5_ctx ctx = (const gsskrb5_ctx) context_handle;
 279   krb5_keyblock *key;
 280   OM_uint32 ret;
 281   krb5_keytype keytype;
 282
 283   GSSAPI_KRB5_INIT (&context);
 284
 285   if (ctx->more_flags & IS_CFX)
 286       return _gssapi_mic_cfx (minor_status, ctx, context, qop_req,
 287                               message_buffer, message_token);
 288
 289   HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
 290   ret = _gsskrb5i_get_token_key(ctx, context, &key);
 291   HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
 292   if (ret) {
 293       *minor_status = ret;
 294       return GSS_S_FAILURE;
 295   }
 296   krb5_enctype_to_keytype (context, key->keytype, &keytype);
 297
 298   switch (keytype) {
 299   case KEYTYPE_DES :
 300       ret = mic_des (minor_status, ctx, context, qop_req,
 301                      message_buffer, message_token, key);
 302       break;
 303   case KEYTYPE_DES3 :
 304       ret = mic_des3 (minor_status, ctx, context, qop_req,
 305                       message_buffer, message_token, key);
 306       break;
 307   case KEYTYPE_ARCFOUR:
 308   case KEYTYPE_ARCFOUR_56:
 309       ret = _gssapi_get_mic_arcfour (minor_status, ctx, context, qop_req,
 310                                      message_buffer, message_token, key);
 311       break;
 312   default :
 313       abort();
 314       break;
 315   }
 316   krb5_free_keyblock (context, key);
 317   return ret;
 318 }