source: heimdal/trunk/lib/gssapi/krb5/get_mic.c

Last change on this file was 1, checked in by Paul Smedley, 10 years ago

Initial commit of Heimdal 1.5.3
File size: 8.9 KB
Line 
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#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 HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
100 /* sequence number */
101 krb5_auth_con_getlocalseqnumber (context,
102 ctx->auth_context,
103 &seq_number);
104
105 p -= 16; /* SND_SEQ */
106 p[0] = (seq_number >> 0) & 0xFF;
107 p[1] = (seq_number >> 8) & 0xFF;
108 p[2] = (seq_number >> 16) & 0xFF;
109 p[3] = (seq_number >> 24) & 0xFF;
110 memset (p + 4,
111 (ctx->more_flags & LOCAL) ? 0 : 0xFF,
112 4);
113
114 EVP_CIPHER_CTX_init(&des_ctx);
115 EVP_CipherInit_ex(&des_ctx, EVP_des_cbc(), NULL, key->keyvalue.data, p + 8, 1);
116 EVP_Cipher(&des_ctx, p, p, 8);
117 EVP_CIPHER_CTX_cleanup(&des_ctx);
118
119 krb5_auth_con_setlocalseqnumber (context,
120 ctx->auth_context,
121 ++seq_number);
122 HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
123
124 memset (deskey, 0, sizeof(deskey));
125 memset (&schedule, 0, sizeof(schedule));
126
127 *minor_status = 0;
128 return GSS_S_COMPLETE;
129}
130#endif
131
132static OM_uint32
133mic_des3
134 (OM_uint32 * minor_status,
135 const gsskrb5_ctx ctx,
136 krb5_context context,
137 gss_qop_t qop_req,
138 const gss_buffer_t message_buffer,
139 gss_buffer_t message_token,
140 krb5_keyblock *key
141 )
142{
143 u_char *p;
144 Checksum cksum;
145 u_char seq[8];
146
147 int32_t seq_number;
148 size_t len, total_len;
149
150 krb5_crypto crypto;
151 krb5_error_code kret;
152 krb5_data encdata;
153 char *tmp;
154 char ivec[8];
155
156 _gsskrb5_encap_length (36, &len, &total_len, GSS_KRB5_MECHANISM);
157
158 message_token->length = total_len;
159 message_token->value = malloc (total_len);
160 if (message_token->value == NULL) {
161 message_token->length = 0;
162 *minor_status = ENOMEM;
163 return GSS_S_FAILURE;
164 }
165
166 p = _gsskrb5_make_header(message_token->value,
167 len,
168 "\x01\x01", /* TOK-ID */
169 GSS_KRB5_MECHANISM);
170
171 memcpy (p, "\x04\x00", 2); /* SGN_ALG = HMAC SHA1 DES3-KD */
172 p += 2;
173
174 memcpy (p, "\xff\xff\xff\xff", 4); /* filler */
175 p += 4;
176
177 /* this should be done in parts */
178
179 tmp = malloc (message_buffer->length + 8);
180 if (tmp == NULL) {
181 free (message_token->value);
182 message_token->value = NULL;
183 message_token->length = 0;
184 *minor_status = ENOMEM;
185 return GSS_S_FAILURE;
186 }
187 memcpy (tmp, p - 8, 8);
188 memcpy (tmp + 8, message_buffer->value, message_buffer->length);
189
190 kret = krb5_crypto_init(context, key, 0, &crypto);
191 if (kret) {
192 free (message_token->value);
193 message_token->value = NULL;
194 message_token->length = 0;
195 free (tmp);
196 *minor_status = kret;
197 return GSS_S_FAILURE;
198 }
199
200 kret = krb5_create_checksum (context,
201 crypto,
202 KRB5_KU_USAGE_SIGN,
203 0,
204 tmp,
205 message_buffer->length + 8,
206 &cksum);
207 free (tmp);
208 krb5_crypto_destroy (context, crypto);
209 if (kret) {
210 free (message_token->value);
211 message_token->value = NULL;
212 message_token->length = 0;
213 *minor_status = kret;
214 return GSS_S_FAILURE;
215 }
216
217 memcpy (p + 8, cksum.checksum.data, cksum.checksum.length);
218
219 HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
220 /* sequence number */
221 krb5_auth_con_getlocalseqnumber (context,
222 ctx->auth_context,
223 &seq_number);
224
225 seq[0] = (seq_number >> 0) & 0xFF;
226 seq[1] = (seq_number >> 8) & 0xFF;
227 seq[2] = (seq_number >> 16) & 0xFF;
228 seq[3] = (seq_number >> 24) & 0xFF;
229 memset (seq + 4,
230 (ctx->more_flags & LOCAL) ? 0 : 0xFF,
231 4);
232
233 kret = krb5_crypto_init(context, key,
234 ETYPE_DES3_CBC_NONE, &crypto);
235 if (kret) {
236 free (message_token->value);
237 message_token->value = NULL;
238 message_token->length = 0;
239 *minor_status = kret;
240 return GSS_S_FAILURE;
241 }
242
243 if (ctx->more_flags & COMPAT_OLD_DES3)
244 memset(ivec, 0, 8);
245 else
246 memcpy(ivec, p + 8, 8);
247
248 kret = krb5_encrypt_ivec (context,
249 crypto,
250 KRB5_KU_USAGE_SEQ,
251 seq, 8, &encdata, ivec);
252 krb5_crypto_destroy (context, crypto);
253 if (kret) {
254 free (message_token->value);
255 message_token->value = NULL;
256 message_token->length = 0;
257 *minor_status = kret;
258 return GSS_S_FAILURE;
259 }
260
261 assert (encdata.length == 8);
262
263 memcpy (p, encdata.data, encdata.length);
264 krb5_data_free (&encdata);
265
266 krb5_auth_con_setlocalseqnumber (context,
267 ctx->auth_context,
268 ++seq_number);
269 HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
270
271 free_Checksum (&cksum);
272 *minor_status = 0;
273 return GSS_S_COMPLETE;
274}
275
276OM_uint32 GSSAPI_CALLCONV _gsskrb5_get_mic
277 (OM_uint32 * minor_status,
278 const gss_ctx_id_t context_handle,
279 gss_qop_t qop_req,
280 const gss_buffer_t message_buffer,
281 gss_buffer_t message_token
282 )
283{
284 krb5_context context;
285 const gsskrb5_ctx ctx = (const gsskrb5_ctx) context_handle;
286 krb5_keyblock *key;
287 OM_uint32 ret;
288 krb5_keytype keytype;
289
290 GSSAPI_KRB5_INIT (&context);
291
292 if (ctx->more_flags & IS_CFX)
293 return _gssapi_mic_cfx (minor_status, ctx, context, qop_req,
294 message_buffer, message_token);
295
296 HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
297 ret = _gsskrb5i_get_token_key(ctx, context, &key);
298 HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
299 if (ret) {
300 *minor_status = ret;
301 return GSS_S_FAILURE;
302 }
303 krb5_enctype_to_keytype (context, key->keytype, &keytype);
304
305 switch (keytype) {
306 case KEYTYPE_DES :
307#ifdef HEIM_WEAK_CRYPTO
308 ret = mic_des (minor_status, ctx, context, qop_req,
309 message_buffer, message_token, key);
310#else
311 ret = GSS_S_FAILURE;
312#endif
313 break;
314 case KEYTYPE_DES3 :
315 ret = mic_des3 (minor_status, ctx, context, qop_req,
316 message_buffer, message_token, key);
317 break;
318 case KEYTYPE_ARCFOUR:
319 case KEYTYPE_ARCFOUR_56:
320 ret = _gssapi_get_mic_arcfour (minor_status, ctx, context, qop_req,
321 message_buffer, message_token, key);
322 break;
323 default :
324 abort();
325 break;
326 }
327 krb5_free_keyblock (context, key);
328 return ret;
329}
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