1/*
2 * Copyright (c) 1997 - 2003 Kungliga Tekniska H��gskolan
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#ifdef HEIM_WEAK_CRYPTO
37
38static OM_uint32
39mic_des
40           (OM_uint32 * minor_status,
41            const gsskrb5_ctx ctx,
42	    krb5_context context,
43            gss_qop_t qop_req,
44            const gss_buffer_t message_buffer,
45            gss_buffer_t message_token,
46	    krb5_keyblock *key
47           )
48{
49  u_char *p;
50  EVP_MD_CTX *md5;
51  u_char hash[16];
52  DES_key_schedule schedule;
53  EVP_CIPHER_CTX *des_ctx;
54  DES_cblock deskey;
55  DES_cblock zero;
56  int32_t seq_number;
57  size_t len, total_len;
58
59  _gsskrb5_encap_length (22, &len, &total_len, GSS_KRB5_MECHANISM);
60
61  message_token->length = total_len;
62  message_token->value  = malloc (total_len);
63  if (message_token->value == NULL) {
64    message_token->length = 0;
65    *minor_status = ENOMEM;
66    return GSS_S_FAILURE;
67  }
68
69  p = _gsskrb5_make_header(message_token->value,
70			      len,
71			      "\x01\x01", /* TOK_ID */
72			      GSS_KRB5_MECHANISM);
73
74  memcpy (p, "\x00\x00", 2);	/* SGN_ALG = DES MAC MD5 */
75  p += 2;
76
77  memcpy (p, "\xff\xff\xff\xff", 4); /* Filler */
78  p += 4;
79
80  /* Fill in later (SND-SEQ) */
81  memset (p, 0, 16);
82  p += 16;
83
84  /* checksum */
85  md5 = EVP_MD_CTX_create();
86  EVP_DigestInit_ex(md5, EVP_md5(), NULL);
87  EVP_DigestUpdate(md5, p - 24, 8);
88  EVP_DigestUpdate(md5, message_buffer->value, message_buffer->length);
89  EVP_DigestFinal_ex(md5, hash, NULL);
90  EVP_MD_CTX_destroy(md5);
91
92  memset (&zero, 0, sizeof(zero));
93  memcpy (&deskey, key->keyvalue.data, sizeof(deskey));
94  DES_set_key_unchecked (&deskey, &schedule);
95  DES_cbc_cksum ((void *)hash, (void *)hash, sizeof(hash),
96		 &schedule, &zero);
97  memcpy (p - 8, hash, 8);	/* SGN_CKSUM */
98
99  des_ctx = EVP_CIPHER_CTX_new();
100  if (des_ctx == NULL) {
101      memset (deskey, 0, sizeof(deskey));
102      memset (&schedule, 0, sizeof(schedule));
103      free (message_token->value);
104      message_token->value = NULL;
105      message_token->length = 0;
106      *minor_status = ENOMEM;
107      return GSS_S_FAILURE;
108  }
109
110  HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
111  /* sequence number */
112  krb5_auth_con_getlocalseqnumber (context,
113				   ctx->auth_context,
114				   &seq_number);
115
116  p -= 16;			/* SND_SEQ */
117  p[0] = (seq_number >> 0)  & 0xFF;
118  p[1] = (seq_number >> 8)  & 0xFF;
119  p[2] = (seq_number >> 16) & 0xFF;
120  p[3] = (seq_number >> 24) & 0xFF;
121  memset (p + 4,
122	  (ctx->more_flags & LOCAL) ? 0 : 0xFF,
123	  4);
124
125  EVP_CipherInit_ex(des_ctx, EVP_des_cbc(), NULL, key->keyvalue.data, p + 8, 1);
126  EVP_Cipher(des_ctx, p, p, 8);
127  EVP_CIPHER_CTX_free(des_ctx);
128
129  krb5_auth_con_setlocalseqnumber (context,
130			       ctx->auth_context,
131			       ++seq_number);
132  HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
133
134  memset (deskey, 0, sizeof(deskey));
135  memset (&schedule, 0, sizeof(schedule));
136
137  *minor_status = 0;
138  return GSS_S_COMPLETE;
139}
140#endif
141
142static OM_uint32
143mic_des3
144           (OM_uint32 * minor_status,
145            const gsskrb5_ctx ctx,
146	    krb5_context context,
147            gss_qop_t qop_req,
148            const gss_buffer_t message_buffer,
149            gss_buffer_t message_token,
150	    krb5_keyblock *key
151           )
152{
153  u_char *p;
154  Checksum cksum;
155  u_char seq[8];
156
157  int32_t seq_number;
158  size_t len, total_len;
159
160  krb5_crypto crypto;
161  krb5_error_code kret;
162  krb5_data encdata;
163  char *tmp;
164  char ivec[8];
165
166  _gsskrb5_encap_length (36, &len, &total_len, GSS_KRB5_MECHANISM);
167
168  message_token->length = total_len;
169  message_token->value  = malloc (total_len);
170  if (message_token->value == NULL) {
171      message_token->length = 0;
172      *minor_status = ENOMEM;
173      return GSS_S_FAILURE;
174  }
175
176  p = _gsskrb5_make_header(message_token->value,
177			      len,
178			      "\x01\x01", /* TOK-ID */
179			      GSS_KRB5_MECHANISM);
180
181  memcpy (p, "\x04\x00", 2);	/* SGN_ALG = HMAC SHA1 DES3-KD */
182  p += 2;
183
184  memcpy (p, "\xff\xff\xff\xff", 4); /* filler */
185  p += 4;
186
187  /* this should be done in parts */
188
189  tmp = malloc (message_buffer->length + 8);
190  if (tmp == NULL) {
191      free (message_token->value);
192      message_token->value = NULL;
193      message_token->length = 0;
194      *minor_status = ENOMEM;
195      return GSS_S_FAILURE;
196  }
197  memcpy (tmp, p - 8, 8);
198  memcpy (tmp + 8, message_buffer->value, message_buffer->length);
199
200  kret = krb5_crypto_init(context, key, 0, &crypto);
201  if (kret) {
202      free (message_token->value);
203      message_token->value = NULL;
204      message_token->length = 0;
205      free (tmp);
206      *minor_status = kret;
207      return GSS_S_FAILURE;
208  }
209
210  kret = krb5_create_checksum (context,
211			       crypto,
212			       KRB5_KU_USAGE_SIGN,
213			       0,
214			       tmp,
215			       message_buffer->length + 8,
216			       &cksum);
217  free (tmp);
218  krb5_crypto_destroy (context, crypto);
219  if (kret) {
220      free (message_token->value);
221      message_token->value = NULL;
222      message_token->length = 0;
223      *minor_status = kret;
224      return GSS_S_FAILURE;
225  }
226
227  memcpy (p + 8, cksum.checksum.data, cksum.checksum.length);
228
229  HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
230  /* sequence number */
231  krb5_auth_con_getlocalseqnumber (context,
232			       ctx->auth_context,
233			       &seq_number);
234
235  seq[0] = (seq_number >> 0)  & 0xFF;
236  seq[1] = (seq_number >> 8)  & 0xFF;
237  seq[2] = (seq_number >> 16) & 0xFF;
238  seq[3] = (seq_number >> 24) & 0xFF;
239  memset (seq + 4,
240	  (ctx->more_flags & LOCAL) ? 0 : 0xFF,
241	  4);
242
243  kret = krb5_crypto_init(context, key,
244			  ETYPE_DES3_CBC_NONE, &crypto);
245  if (kret) {
246      free (message_token->value);
247      message_token->value = NULL;
248      message_token->length = 0;
249      *minor_status = kret;
250      return GSS_S_FAILURE;
251  }
252
253  if (ctx->more_flags & COMPAT_OLD_DES3)
254      memset(ivec, 0, 8);
255  else
256      memcpy(ivec, p + 8, 8);
257
258  kret = krb5_encrypt_ivec (context,
259			    crypto,
260			    KRB5_KU_USAGE_SEQ,
261			    seq, 8, &encdata, ivec);
262  krb5_crypto_destroy (context, crypto);
263  if (kret) {
264      free (message_token->value);
265      message_token->value = NULL;
266      message_token->length = 0;
267      *minor_status = kret;
268      return GSS_S_FAILURE;
269  }
270
271  assert (encdata.length == 8);
272
273  memcpy (p, encdata.data, encdata.length);
274  krb5_data_free (&encdata);
275
276  krb5_auth_con_setlocalseqnumber (context,
277			       ctx->auth_context,
278			       ++seq_number);
279  HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
280
281  free_Checksum (&cksum);
282  *minor_status = 0;
283  return GSS_S_COMPLETE;
284}
285
286OM_uint32 GSSAPI_CALLCONV _gsskrb5_get_mic
287           (OM_uint32 * minor_status,
288            const gss_ctx_id_t context_handle,
289            gss_qop_t qop_req,
290            const gss_buffer_t message_buffer,
291            gss_buffer_t message_token
292           )
293{
294  krb5_context context;
295  const gsskrb5_ctx ctx = (const gsskrb5_ctx) context_handle;
296  krb5_keyblock *key;
297  OM_uint32 ret;
298  krb5_keytype keytype;
299
300  GSSAPI_KRB5_INIT (&context);
301
302  if (ctx->more_flags & IS_CFX)
303      return _gssapi_mic_cfx (minor_status, ctx, context, qop_req,
304			      message_buffer, message_token);
305
306  HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
307  ret = _gsskrb5i_get_token_key(ctx, context, &key);
308  HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
309  if (ret) {
310      *minor_status = ret;
311      return GSS_S_FAILURE;
312  }
313  krb5_enctype_to_keytype (context, key->keytype, &keytype);
314
315  switch (keytype) {
316  case KEYTYPE_DES :
317#ifdef HEIM_WEAK_CRYPTO
318      ret = mic_des (minor_status, ctx, context, qop_req,
319		     message_buffer, message_token, key);
320#else
321      ret = GSS_S_FAILURE;
322#endif
323      break;
324  case KEYTYPE_DES3 :
325      ret = mic_des3 (minor_status, ctx, context, qop_req,
326		      message_buffer, message_token, key);
327      break;
328  case KEYTYPE_ARCFOUR:
329  case KEYTYPE_ARCFOUR_56:
330      ret = _gssapi_get_mic_arcfour (minor_status, ctx, context, qop_req,
331				     message_buffer, message_token, key);
332      break;
333  default :
334      abort();
335      break;
336  }
337  krb5_free_keyblock (context, key);
338  return ret;
339}
340