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34 #include "gssapi_locl.h"
36 RCSID("$Id: verify_mic.c,v 1.16 2002/05/20 15:14:00 nectar Exp $");
40 (OM_uint32 * minor_status,
41 const gss_ctx_id_t context_handle,
42 const gss_buffer_t message_buffer,
43 const gss_buffer_t token_buffer,
44 gss_qop_t * qop_state,
50 u_char hash[16], seq_data[8];
51 des_key_schedule schedule;
57 p = token_buffer->value;
58 ret = gssapi_krb5_verify_header (&p,
66 if (memcmp(p, "\x00\x00", 2) != 0)
69 if (memcmp (p, "\xff\xff\xff\xff", 4) != 0)
76 MD5_Update (&md5, p - 24, 8);
77 MD5_Update (&md5, message_buffer->value,
78 message_buffer->length);
79 MD5_Final (hash, &md5);
81 memset (&zero, 0, sizeof(zero));
82 memcpy (&deskey, key->keyvalue.data, sizeof(deskey));
84 des_set_key (&deskey, schedule);
85 des_cbc_cksum ((void *)hash, (void *)hash, sizeof(hash),
87 if (memcmp (p - 8, hash, 8) != 0) {
88 memset (deskey, 0, sizeof(deskey));
89 memset (schedule, 0, sizeof(schedule));
93 /* verify sequence number */
95 krb5_auth_getremoteseqnumber (gssapi_krb5_context,
96 context_handle->auth_context,
98 seq_data[0] = (seq_number >> 0) & 0xFF;
99 seq_data[1] = (seq_number >> 8) & 0xFF;
100 seq_data[2] = (seq_number >> 16) & 0xFF;
101 seq_data[3] = (seq_number >> 24) & 0xFF;
102 memset (seq_data + 4,
103 (context_handle->more_flags & LOCAL) ? 0xFF : 0,
107 des_set_key (&deskey, schedule);
108 des_cbc_encrypt ((void *)p, (void *)p, 8,
109 schedule, (des_cblock *)hash, DES_DECRYPT);
111 memset (deskey, 0, sizeof(deskey));
112 memset (schedule, 0, sizeof(schedule));
114 if (memcmp (p, seq_data, 8) != 0) {
115 return GSS_S_BAD_MIC;
118 krb5_auth_con_setremoteseqnumber (gssapi_krb5_context,
119 context_handle->auth_context,
122 return GSS_S_COMPLETE;
127 (OM_uint32 * minor_status,
128 const gss_ctx_id_t context_handle,
129 const gss_buffer_t message_buffer,
130 const gss_buffer_t token_buffer,
131 gss_qop_t * qop_state,
145 p = token_buffer->value;
146 ret = gssapi_krb5_verify_header (&p,
147 token_buffer->length,
154 if (memcmp(p, "\x04\x00", 2) != 0) /* SGN_ALG = HMAC SHA1 DES3-KD */
155 return GSS_S_BAD_SIG;
157 if (memcmp (p, "\xff\xff\xff\xff", 4) != 0)
158 return GSS_S_BAD_MIC;
161 ret = krb5_crypto_init(gssapi_krb5_context, key,
162 ETYPE_DES3_CBC_NONE, &crypto);
164 gssapi_krb5_set_error_string ();
166 return GSS_S_FAILURE;
169 /* verify sequence number */
171 ret = krb5_decrypt (gssapi_krb5_context,
176 gssapi_krb5_set_error_string ();
177 krb5_crypto_destroy (gssapi_krb5_context, crypto);
179 return GSS_S_FAILURE;
182 if (seq_data.length != 8) {
183 krb5_crypto_destroy (gssapi_krb5_context, crypto);
184 krb5_data_free (&seq_data);
185 return GSS_S_BAD_MIC;
188 krb5_auth_getremoteseqnumber (gssapi_krb5_context,
189 context_handle->auth_context,
191 seq[0] = (seq_number >> 0) & 0xFF;
192 seq[1] = (seq_number >> 8) & 0xFF;
193 seq[2] = (seq_number >> 16) & 0xFF;
194 seq[3] = (seq_number >> 24) & 0xFF;
196 (context_handle->more_flags & LOCAL) ? 0xFF : 0,
198 cmp = memcmp (seq, seq_data.data, seq_data.length);
199 krb5_data_free (&seq_data);
201 krb5_crypto_destroy (gssapi_krb5_context, crypto);
202 return GSS_S_BAD_MIC;
205 /* verify checksum */
207 tmp = malloc (message_buffer->length + 8);
209 krb5_crypto_destroy (gssapi_krb5_context, crypto);
210 *minor_status = ENOMEM;
211 return GSS_S_FAILURE;
214 memcpy (tmp, p - 8, 8);
215 memcpy (tmp + 8, message_buffer->value, message_buffer->length);
217 csum.cksumtype = CKSUMTYPE_HMAC_SHA1_DES3;
218 csum.checksum.length = 20;
219 csum.checksum.data = p + 8;
221 ret = krb5_verify_checksum (gssapi_krb5_context, crypto,
223 tmp, message_buffer->length + 8,
227 gssapi_krb5_set_error_string ();
228 krb5_crypto_destroy (gssapi_krb5_context, crypto);
230 return GSS_S_BAD_MIC;
233 krb5_auth_con_setremoteseqnumber (gssapi_krb5_context,
234 context_handle->auth_context,
237 krb5_crypto_destroy (gssapi_krb5_context, crypto);
238 return GSS_S_COMPLETE;
243 (OM_uint32 * minor_status,
244 const gss_ctx_id_t context_handle,
245 const gss_buffer_t message_buffer,
246 const gss_buffer_t token_buffer,
247 gss_qop_t * qop_state
252 krb5_keytype keytype;
254 if (qop_state != NULL)
255 *qop_state = GSS_C_QOP_DEFAULT;
256 ret = gss_krb5_get_remotekey(context_handle, &key);
258 gssapi_krb5_set_error_string ();
260 return GSS_S_FAILURE;
262 krb5_enctype_to_keytype (gssapi_krb5_context, key->keytype, &keytype);
265 ret = verify_mic_des (minor_status, context_handle,
266 message_buffer, token_buffer, qop_state, key);
269 ret = verify_mic_des3 (minor_status, context_handle,
270 message_buffer, token_buffer, qop_state, key);
273 *minor_status = KRB5_PROG_ETYPE_NOSUPP;
277 krb5_free_keyblock (gssapi_krb5_context, key);