Line data Source code
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 :
38 : static OM_uint32
39 : verify_mic_des
40 : (OM_uint32 * minor_status,
41 : const gsskrb5_ctx context_handle,
42 : krb5_context context,
43 : const gss_buffer_t message_buffer,
44 : const gss_buffer_t token_buffer,
45 : gss_qop_t * qop_state,
46 : krb5_keyblock *key,
47 : const char *type
48 : )
49 : {
50 : u_char *p;
51 : EVP_MD_CTX *md5;
52 : u_char hash[16], *seq;
53 : DES_key_schedule schedule;
54 : EVP_CIPHER_CTX des_ctx;
55 : DES_cblock zero;
56 : DES_cblock deskey;
57 : uint32_t seq_number;
58 : OM_uint32 ret;
59 : int cmp;
60 :
61 : p = token_buffer->value;
62 : ret = _gsskrb5_verify_header (&p,
63 : token_buffer->length,
64 : type,
65 : GSS_KRB5_MECHANISM);
66 : if (ret)
67 : return ret;
68 :
69 : if (memcmp(p, "\x00\x00", 2) != 0)
70 : return GSS_S_BAD_SIG;
71 : p += 2;
72 : if (memcmp (p, "\xff\xff\xff\xff", 4) != 0)
73 : return GSS_S_BAD_MIC;
74 : p += 4;
75 : p += 16;
76 :
77 : /* verify checksum */
78 : md5 = EVP_MD_CTX_create();
79 : EVP_DigestInit_ex(md5, EVP_md5(), NULL);
80 : EVP_DigestUpdate(md5, p - 24, 8);
81 : EVP_DigestUpdate(md5, message_buffer->value, message_buffer->length);
82 : EVP_DigestFinal_ex(md5, hash, NULL);
83 : EVP_MD_CTX_destroy(md5);
84 :
85 : memset (&zero, 0, sizeof(zero));
86 : memcpy (&deskey, key->keyvalue.data, sizeof(deskey));
87 :
88 : DES_set_key_unchecked (&deskey, &schedule);
89 : DES_cbc_cksum ((void *)hash, (void *)hash, sizeof(hash),
90 : &schedule, &zero);
91 : if (ct_memcmp (p - 8, hash, 8) != 0) {
92 : memset_s(deskey, sizeof(deskey), 0, sizeof(deskey));
93 : memset_s(&schedule, sizeof(schedule), 0, sizeof(schedule));
94 : return GSS_S_BAD_MIC;
95 : }
96 :
97 : /* verify sequence number */
98 :
99 : HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
100 :
101 : p -= 16;
102 :
103 : EVP_CIPHER_CTX_init(&des_ctx);
104 : EVP_CipherInit_ex(&des_ctx, EVP_des_cbc(), NULL, key->keyvalue.data, hash, 0);
105 : EVP_Cipher(&des_ctx, p, p, 8);
106 : EVP_CIPHER_CTX_cleanup(&des_ctx);
107 :
108 : memset_s(deskey, sizeof(deskey), 0, sizeof(deskey));
109 : memset_s(&schedule, sizeof(schedule), 0, sizeof(schedule));
110 :
111 : seq = p;
112 : _gss_mg_decode_be_uint32(seq, &seq_number);
113 :
114 : if (context_handle->more_flags & LOCAL)
115 : cmp = ct_memcmp(&seq[4], "\xff\xff\xff\xff", 4);
116 : else
117 : cmp = ct_memcmp(&seq[4], "\x00\x00\x00\x00", 4);
118 :
119 : if (cmp != 0) {
120 : HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
121 : return GSS_S_BAD_MIC;
122 : }
123 :
124 : ret = _gssapi_msg_order_check(context_handle->order, seq_number);
125 : if (ret) {
126 : HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
127 : return ret;
128 : }
129 :
130 : HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
131 :
132 : return GSS_S_COMPLETE;
133 : }
134 : #endif
135 :
136 : static OM_uint32
137 0 : verify_mic_des3
138 : (OM_uint32 * minor_status,
139 : const gsskrb5_ctx context_handle,
140 : krb5_context context,
141 : const gss_buffer_t message_buffer,
142 : const gss_buffer_t token_buffer,
143 : gss_qop_t * qop_state,
144 : krb5_keyblock *key,
145 : const char *type
146 : )
147 : {
148 0 : u_char *p;
149 0 : u_char *seq;
150 0 : uint32_t seq_number;
151 0 : OM_uint32 ret;
152 0 : krb5_crypto crypto;
153 0 : krb5_data seq_data;
154 0 : int cmp, docompat;
155 0 : Checksum csum;
156 0 : char *tmp;
157 0 : char ivec[8];
158 :
159 0 : p = token_buffer->value;
160 0 : ret = _gsskrb5_verify_header (&p,
161 : token_buffer->length,
162 : type,
163 : GSS_KRB5_MECHANISM);
164 0 : if (ret)
165 0 : return ret;
166 :
167 0 : if (memcmp(p, "\x04\x00", 2) != 0) /* SGN_ALG = HMAC SHA1 DES3-KD */
168 0 : return GSS_S_BAD_SIG;
169 0 : p += 2;
170 0 : if (memcmp (p, "\xff\xff\xff\xff", 4) != 0)
171 0 : return GSS_S_BAD_MIC;
172 0 : p += 4;
173 :
174 0 : ret = krb5_crypto_init(context, key,
175 : ETYPE_DES3_CBC_NONE, &crypto);
176 0 : if (ret){
177 0 : *minor_status = ret;
178 0 : return GSS_S_FAILURE;
179 : }
180 :
181 : /* verify sequence number */
182 0 : docompat = 0;
183 0 : retry:
184 0 : if (docompat)
185 0 : memset(ivec, 0, 8);
186 : else
187 0 : memcpy(ivec, p + 8, 8);
188 :
189 0 : ret = krb5_decrypt_ivec (context,
190 : crypto,
191 : KRB5_KU_USAGE_SEQ,
192 : p, 8, &seq_data, ivec);
193 0 : if (ret) {
194 0 : if (docompat++) {
195 0 : krb5_crypto_destroy (context, crypto);
196 0 : *minor_status = ret;
197 0 : return GSS_S_FAILURE;
198 : } else
199 0 : goto retry;
200 : }
201 :
202 0 : if (seq_data.length != 8) {
203 0 : krb5_data_free (&seq_data);
204 0 : if (docompat++) {
205 0 : krb5_crypto_destroy (context, crypto);
206 0 : return GSS_S_BAD_MIC;
207 : } else
208 0 : goto retry;
209 : }
210 :
211 0 : HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
212 :
213 0 : seq = seq_data.data;
214 0 : _gss_mg_decode_be_uint32(seq, &seq_number);
215 :
216 0 : if (context_handle->more_flags & LOCAL)
217 0 : cmp = ct_memcmp(&seq[4], "\xff\xff\xff\xff", 4);
218 : else
219 0 : cmp = ct_memcmp(&seq[4], "\x00\x00\x00\x00", 4);
220 :
221 0 : krb5_data_free (&seq_data);
222 0 : if (cmp != 0) {
223 0 : krb5_crypto_destroy (context, crypto);
224 0 : *minor_status = 0;
225 0 : HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
226 0 : return GSS_S_BAD_MIC;
227 : }
228 :
229 0 : ret = _gssapi_msg_order_check(context_handle->order, seq_number);
230 0 : if (ret) {
231 0 : krb5_crypto_destroy (context, crypto);
232 0 : *minor_status = 0;
233 0 : HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
234 0 : return ret;
235 : }
236 :
237 : /* verify checksum */
238 :
239 0 : tmp = malloc (message_buffer->length + 8);
240 0 : if (tmp == NULL) {
241 0 : krb5_crypto_destroy (context, crypto);
242 0 : HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
243 0 : *minor_status = ENOMEM;
244 0 : return GSS_S_FAILURE;
245 : }
246 :
247 0 : memcpy (tmp, p - 8, 8);
248 0 : memcpy (tmp + 8, message_buffer->value, message_buffer->length);
249 :
250 0 : csum.cksumtype = CKSUMTYPE_HMAC_SHA1_DES3;
251 0 : csum.checksum.length = 20;
252 0 : csum.checksum.data = p + 8;
253 :
254 0 : krb5_crypto_destroy (context, crypto);
255 0 : ret = krb5_crypto_init(context, key,
256 : ETYPE_DES3_CBC_SHA1, &crypto);
257 0 : if (ret == 0)
258 0 : ret = krb5_verify_checksum(context, crypto,
259 : KRB5_KU_USAGE_SIGN,
260 0 : tmp, message_buffer->length + 8,
261 : &csum);
262 0 : free (tmp);
263 0 : if (ret) {
264 0 : krb5_crypto_destroy (context, crypto);
265 0 : *minor_status = ret;
266 0 : HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
267 0 : return GSS_S_BAD_MIC;
268 : }
269 0 : HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
270 :
271 0 : krb5_crypto_destroy (context, crypto);
272 0 : return GSS_S_COMPLETE;
273 : }
274 :
275 : OM_uint32
276 251715 : _gsskrb5_verify_mic_internal
277 : (OM_uint32 * minor_status,
278 : const gsskrb5_ctx ctx,
279 : krb5_context context,
280 : const gss_buffer_t message_buffer,
281 : const gss_buffer_t token_buffer,
282 : gss_qop_t * qop_state,
283 : const char * type
284 : )
285 : {
286 317 : krb5_keyblock *key;
287 317 : OM_uint32 ret;
288 :
289 251715 : if (ctx->more_flags & IS_CFX)
290 236542 : return _gssapi_verify_mic_cfx (minor_status, ctx,
291 : context, message_buffer, token_buffer,
292 : qop_state);
293 :
294 0 : HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
295 15173 : ret = _gsskrb5i_get_token_key(ctx, context, &key);
296 0 : HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
297 15173 : if (ret) {
298 0 : *minor_status = ret;
299 0 : return GSS_S_FAILURE;
300 : }
301 15173 : *minor_status = 0;
302 :
303 15173 : switch (key->keytype) {
304 0 : case KRB5_ENCTYPE_DES_CBC_CRC :
305 : case KRB5_ENCTYPE_DES_CBC_MD4 :
306 : case KRB5_ENCTYPE_DES_CBC_MD5 :
307 : #ifdef HEIM_WEAK_CRYPTO
308 : ret = verify_mic_des (minor_status, ctx, context,
309 : message_buffer, token_buffer, qop_state, key,
310 : type);
311 : #else
312 0 : ret = GSS_S_FAILURE;
313 : #endif
314 0 : break;
315 0 : case KRB5_ENCTYPE_DES3_CBC_MD5 :
316 : case KRB5_ENCTYPE_DES3_CBC_SHA1 :
317 0 : ret = verify_mic_des3 (minor_status, ctx, context,
318 : message_buffer, token_buffer, qop_state, key,
319 : type);
320 0 : break;
321 15173 : case KRB5_ENCTYPE_ARCFOUR_HMAC_MD5:
322 : case KRB5_ENCTYPE_ARCFOUR_HMAC_MD5_56:
323 15173 : ret = _gssapi_verify_mic_arcfour (minor_status, ctx,
324 : context,
325 : message_buffer, token_buffer,
326 : qop_state, key, type);
327 15173 : break;
328 0 : default :
329 0 : abort();
330 : }
331 15173 : krb5_free_keyblock (context, key);
332 :
333 15173 : return ret;
334 : }
335 :
336 : OM_uint32 GSSAPI_CALLCONV
337 251715 : _gsskrb5_verify_mic
338 : (OM_uint32 * minor_status,
339 : gss_const_ctx_id_t context_handle,
340 : const gss_buffer_t message_buffer,
341 : const gss_buffer_t token_buffer,
342 : gss_qop_t * qop_state
343 : )
344 : {
345 317 : krb5_context context;
346 317 : OM_uint32 ret;
347 :
348 251715 : GSSAPI_KRB5_INIT (&context);
349 :
350 251715 : if (qop_state != NULL)
351 251715 : *qop_state = GSS_C_QOP_DEFAULT;
352 :
353 251715 : ret = _gsskrb5_verify_mic_internal(minor_status,
354 : (gsskrb5_ctx)context_handle,
355 : context,
356 : message_buffer, token_buffer,
357 : qop_state, (void *)(intptr_t)"\x01\x01");
358 :
359 251715 : return ret;
360 : }
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