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/*
* Copyright (c) 1997 - 2003 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "krb5/gsskrb5_locl.h"
RCSID("$Id: verify_mic.c 23112 2008-04-27 18:51:26Z lha $");
static OM_uint32
verify_mic_des
(OM_uint32 * minor_status,
const gsskrb5_ctx context_handle,
krb5_context context,
const gss_buffer_t message_buffer,
const gss_buffer_t token_buffer,
gss_qop_t * qop_state,
krb5_keyblock *key,
char *type
)
{
u_char *p;
MD5_CTX md5;
u_char hash[16], *seq;
DES_key_schedule schedule;
DES_cblock zero;
DES_cblock deskey;
uint32_t seq_number;
OM_uint32 ret;
int cmp;
p = token_buffer->value;
ret = _gsskrb5_verify_header (&p,
token_buffer->length,
type,
GSS_KRB5_MECHANISM);
if (ret)
return ret;
if (memcmp(p, "\x00\x00", 2) != 0)
return GSS_S_BAD_SIG;
p += 2;
if (memcmp (p, "\xff\xff\xff\xff", 4) != 0)
return GSS_S_BAD_MIC;
p += 4;
p += 16;
/* verify checksum */
MD5_Init (&md5);
MD5_Update (&md5, p - 24, 8);
MD5_Update (&md5, message_buffer->value,
message_buffer->length);
MD5_Final (hash, &md5);
memset (&zero, 0, sizeof(zero));
memcpy (&deskey, key->keyvalue.data, sizeof(deskey));
DES_set_key_unchecked (&deskey, &schedule);
DES_cbc_cksum ((void *)hash, (void *)hash, sizeof(hash),
&schedule, &zero);
if (memcmp (p - 8, hash, 8) != 0) {
memset (deskey, 0, sizeof(deskey));
memset (&schedule, 0, sizeof(schedule));
return GSS_S_BAD_MIC;
}
/* verify sequence number */
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
p -= 16;
DES_set_key_unchecked (&deskey, &schedule);
DES_cbc_encrypt ((void *)p, (void *)p, 8,
&schedule, (DES_cblock *)hash, DES_DECRYPT);
memset (deskey, 0, sizeof(deskey));
memset (&schedule, 0, sizeof(schedule));
seq = p;
_gsskrb5_decode_om_uint32(seq, &seq_number);
if (context_handle->more_flags & LOCAL)
cmp = memcmp(&seq[4], "\xff\xff\xff\xff", 4);
else
cmp = memcmp(&seq[4], "\x00\x00\x00\x00", 4);
if (cmp != 0) {
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
return GSS_S_BAD_MIC;
}
ret = _gssapi_msg_order_check(context_handle->order, seq_number);
if (ret) {
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
return ret;
}
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
return GSS_S_COMPLETE;
}
static OM_uint32
verify_mic_des3
(OM_uint32 * minor_status,
const gsskrb5_ctx context_handle,
krb5_context context,
const gss_buffer_t message_buffer,
const gss_buffer_t token_buffer,
gss_qop_t * qop_state,
krb5_keyblock *key,
char *type
)
{
u_char *p;
u_char *seq;
uint32_t seq_number;
OM_uint32 ret;
krb5_crypto crypto;
krb5_data seq_data;
int cmp, docompat;
Checksum csum;
char *tmp;
char ivec[8];
p = token_buffer->value;
ret = _gsskrb5_verify_header (&p,
token_buffer->length,
type,
GSS_KRB5_MECHANISM);
if (ret)
return ret;
if (memcmp(p, "\x04\x00", 2) != 0) /* SGN_ALG = HMAC SHA1 DES3-KD */
return GSS_S_BAD_SIG;
p += 2;
if (memcmp (p, "\xff\xff\xff\xff", 4) != 0)
return GSS_S_BAD_MIC;
p += 4;
ret = krb5_crypto_init(context, key,
ETYPE_DES3_CBC_NONE, &crypto);
if (ret){
*minor_status = ret;
return GSS_S_FAILURE;
}
/* verify sequence number */
docompat = 0;
retry:
if (docompat)
memset(ivec, 0, 8);
else
memcpy(ivec, p + 8, 8);
ret = krb5_decrypt_ivec (context,
crypto,
KRB5_KU_USAGE_SEQ,
p, 8, &seq_data, ivec);
if (ret) {
if (docompat++) {
krb5_crypto_destroy (context, crypto);
*minor_status = ret;
return GSS_S_FAILURE;
} else
goto retry;
}
if (seq_data.length != 8) {
krb5_data_free (&seq_data);
if (docompat++) {
krb5_crypto_destroy (context, crypto);
return GSS_S_BAD_MIC;
} else
goto retry;
}
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
seq = seq_data.data;
_gsskrb5_decode_om_uint32(seq, &seq_number);
if (context_handle->more_flags & LOCAL)
cmp = memcmp(&seq[4], "\xff\xff\xff\xff", 4);
else
cmp = memcmp(&seq[4], "\x00\x00\x00\x00", 4);
krb5_data_free (&seq_data);
if (cmp != 0) {
krb5_crypto_destroy (context, crypto);
*minor_status = 0;
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
return GSS_S_BAD_MIC;
}
ret = _gssapi_msg_order_check(context_handle->order, seq_number);
if (ret) {
krb5_crypto_destroy (context, crypto);
*minor_status = 0;
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
return ret;
}
/* verify checksum */
tmp = malloc (message_buffer->length + 8);
if (tmp == NULL) {
krb5_crypto_destroy (context, crypto);
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
memcpy (tmp, p - 8, 8);
memcpy (tmp + 8, message_buffer->value, message_buffer->length);
csum.cksumtype = CKSUMTYPE_HMAC_SHA1_DES3;
csum.checksum.length = 20;
csum.checksum.data = p + 8;
ret = krb5_verify_checksum (context, crypto,
KRB5_KU_USAGE_SIGN,
tmp, message_buffer->length + 8,
&csum);
free (tmp);
if (ret) {
krb5_crypto_destroy (context, crypto);
*minor_status = ret;
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
return GSS_S_BAD_MIC;
}
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
krb5_crypto_destroy (context, crypto);
return GSS_S_COMPLETE;
}
OM_uint32
_gsskrb5_verify_mic_internal
(OM_uint32 * minor_status,
const gsskrb5_ctx context_handle,
krb5_context context,
const gss_buffer_t message_buffer,
const gss_buffer_t token_buffer,
gss_qop_t * qop_state,
char * type
)
{
krb5_keyblock *key;
OM_uint32 ret;
krb5_keytype keytype;
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
ret = _gsskrb5i_get_token_key(context_handle, context, &key);
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
if (ret) {
*minor_status = ret;
return GSS_S_FAILURE;
}
*minor_status = 0;
krb5_enctype_to_keytype (context, key->keytype, &keytype);
switch (keytype) {
case KEYTYPE_DES :
ret = verify_mic_des (minor_status, context_handle, context,
message_buffer, token_buffer, qop_state, key,
type);
break;
case KEYTYPE_DES3 :
ret = verify_mic_des3 (minor_status, context_handle, context,
message_buffer, token_buffer, qop_state, key,
type);
break;
case KEYTYPE_ARCFOUR :
case KEYTYPE_ARCFOUR_56 :
ret = _gssapi_verify_mic_arcfour (minor_status, context_handle,
context,
message_buffer, token_buffer,
qop_state, key, type);
break;
default :
ret = _gssapi_verify_mic_cfx (minor_status, context_handle,
context,
message_buffer, token_buffer, qop_state,
key);
break;
}
krb5_free_keyblock (context, key);
return ret;
}
OM_uint32
_gsskrb5_verify_mic
(OM_uint32 * minor_status,
const gss_ctx_id_t context_handle,
const gss_buffer_t message_buffer,
const gss_buffer_t token_buffer,
gss_qop_t * qop_state
)
{
krb5_context context;
OM_uint32 ret;
GSSAPI_KRB5_INIT (&context);
if (qop_state != NULL)
*qop_state = GSS_C_QOP_DEFAULT;
ret = _gsskrb5_verify_mic_internal(minor_status,
(gsskrb5_ctx)context_handle,
context,
message_buffer, token_buffer,
qop_state, "\x01\x01");
return ret;
}
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