OpenBSD-4.6/kerberosV/src/lib/gssapi/arcfour.c
/*
* Copyright (c) 2003 - 2004 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 "gssapi_locl.h"
RCSID("$KTH: arcfour.c,v 1.17 2005/05/06 07:13:32 lha Exp $");
/*
* Implements draft-brezak-win2k-krb-rc4-hmac-04.txt
*
* The arcfour message have the following formats:
*
* MIC token
* TOK_ID[2] = 01 01
* SGN_ALG[2] = 11 00
* Filler[4]
* SND_SEQ[8]
* SGN_CKSUM[8]
*
* WRAP token
* TOK_ID[2] = 02 01
* SGN_ALG[2];
* SEAL_ALG[2]
* Filler[2]
* SND_SEQ[2]
* SGN_CKSUM[8]
* Confounder[8]
*/
static krb5_error_code
arcfour_mic_key(krb5_context context, krb5_keyblock *key,
void *cksum_data, size_t cksum_size,
void *key6_data, size_t key6_size)
{
krb5_error_code ret;
Checksum cksum_k5;
krb5_keyblock key5;
char k5_data[16];
Checksum cksum_k6;
char T[4];
memset(T, 0, 4);
cksum_k5.checksum.data = k5_data;
cksum_k5.checksum.length = sizeof(k5_data);
if (key->keytype == KEYTYPE_ARCFOUR_56) {
char L40[14] = "fortybits";
memcpy(L40 + 10, T, sizeof(T));
ret = krb5_hmac(context, CKSUMTYPE_RSA_MD5,
L40, 14, 0, key, &cksum_k5);
memset(&k5_data[7], 0xAB, 9);
} else {
ret = krb5_hmac(context, CKSUMTYPE_RSA_MD5,
T, 4, 0, key, &cksum_k5);
}
if (ret)
return ret;
key5.keytype = KEYTYPE_ARCFOUR;
key5.keyvalue = cksum_k5.checksum;
cksum_k6.checksum.data = key6_data;
cksum_k6.checksum.length = key6_size;
return krb5_hmac(context, CKSUMTYPE_RSA_MD5,
cksum_data, cksum_size, 0, &key5, &cksum_k6);
}
static krb5_error_code
arcfour_mic_cksum(krb5_keyblock *key, unsigned usage,
u_char *sgn_cksum, size_t sgn_cksum_sz,
const char *v1, size_t l1,
const void *v2, size_t l2,
const void *v3, size_t l3)
{
Checksum CKSUM;
u_char *ptr;
size_t len;
krb5_crypto crypto;
krb5_error_code ret;
assert(sgn_cksum_sz == 8);
len = l1 + l2 + l3;
ptr = malloc(len);
if (ptr == NULL)
return ENOMEM;
memcpy(ptr, v1, l1);
memcpy(ptr + l1, v2, l2);
memcpy(ptr + l1 + l2, v3, l3);
ret = krb5_crypto_init(gssapi_krb5_context, key, 0, &crypto);
if (ret) {
free(ptr);
return ret;
}
ret = krb5_create_checksum(gssapi_krb5_context,
crypto,
usage,
0,
ptr, len,
&CKSUM);
free(ptr);
if (ret == 0) {
memcpy(sgn_cksum, CKSUM.checksum.data, sgn_cksum_sz);
free_Checksum(&CKSUM);
}
krb5_crypto_destroy(gssapi_krb5_context, crypto);
return ret;
}
OM_uint32
_gssapi_get_mic_arcfour(OM_uint32 * minor_status,
const gss_ctx_id_t context_handle,
gss_qop_t qop_req,
const gss_buffer_t message_buffer,
gss_buffer_t message_token,
krb5_keyblock *key)
{
krb5_error_code ret;
int32_t seq_number;
size_t len, total_len;
u_char k6_data[16], *p0, *p;
RC4_KEY rc4_key;
gssapi_krb5_encap_length (22, &len, &total_len, GSS_KRB5_MECHANISM);
message_token->length = total_len;
message_token->value = malloc (total_len);
if (message_token->value == NULL) {
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
p0 = _gssapi_make_mech_header(message_token->value,
len,
GSS_KRB5_MECHANISM);
p = p0;
*p++ = 0x01; /* TOK_ID */
*p++ = 0x01;
*p++ = 0x11; /* SGN_ALG */
*p++ = 0x00;
*p++ = 0xff; /* Filler */
*p++ = 0xff;
*p++ = 0xff;
*p++ = 0xff;
p = NULL;
ret = arcfour_mic_cksum(key, KRB5_KU_USAGE_SIGN,
p0 + 16, 8, /* SGN_CKSUM */
p0, 8, /* TOK_ID, SGN_ALG, Filer */
message_buffer->value, message_buffer->length,
NULL, 0);
if (ret) {
gss_release_buffer(minor_status, message_token);
*minor_status = ret;
return GSS_S_FAILURE;
}
ret = arcfour_mic_key(gssapi_krb5_context, key,
p0 + 16, 8, /* SGN_CKSUM */
k6_data, sizeof(k6_data));
if (ret) {
gss_release_buffer(minor_status, message_token);
*minor_status = ret;
return GSS_S_FAILURE;
}
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
krb5_auth_con_getlocalseqnumber (gssapi_krb5_context,
context_handle->auth_context,
&seq_number);
p = p0 + 8; /* SND_SEQ */
gssapi_encode_be_om_uint32(seq_number, p);
krb5_auth_con_setlocalseqnumber (gssapi_krb5_context,
context_handle->auth_context,
++seq_number);
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
memset (p + 4, (context_handle->more_flags & LOCAL) ? 0 : 0xff, 4);
RC4_set_key (&rc4_key, sizeof(k6_data), k6_data);
RC4 (&rc4_key, 8, p, p);
memset(&rc4_key, 0, sizeof(rc4_key));
memset(k6_data, 0, sizeof(k6_data));
*minor_status = 0;
return GSS_S_COMPLETE;
}
OM_uint32
_gssapi_verify_mic_arcfour(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_keyblock *key,
char *type)
{
krb5_error_code ret;
int32_t seq_number;
OM_uint32 omret;
char cksum_data[8], k6_data[16], SND_SEQ[8];
u_char *p;
int cmp;
if (qop_state)
*qop_state = 0;
p = token_buffer->value;
omret = gssapi_krb5_verify_header (&p,
token_buffer->length,
type,
GSS_KRB5_MECHANISM);
if (omret)
return omret;
if (memcmp(p, "\x11\x00", 2) != 0) /* SGN_ALG = HMAC MD5 ARCFOUR */
return GSS_S_BAD_SIG;
p += 2;
if (memcmp (p, "\xff\xff\xff\xff", 4) != 0)
return GSS_S_BAD_MIC;
p += 4;
ret = arcfour_mic_cksum(key, KRB5_KU_USAGE_SIGN,
cksum_data, sizeof(cksum_data),
p - 8, 8,
message_buffer->value, message_buffer->length,
NULL, 0);
if (ret) {
*minor_status = ret;
return GSS_S_FAILURE;
}
ret = arcfour_mic_key(gssapi_krb5_context, key,
cksum_data, sizeof(cksum_data),
k6_data, sizeof(k6_data));
if (ret) {
*minor_status = ret;
return GSS_S_FAILURE;
}
cmp = memcmp(cksum_data, p + 8, 8);
if (cmp) {
*minor_status = 0;
return GSS_S_BAD_MIC;
}
{
RC4_KEY rc4_key;
RC4_set_key (&rc4_key, sizeof(k6_data), k6_data);
RC4 (&rc4_key, 8, p, SND_SEQ);
memset(&rc4_key, 0, sizeof(rc4_key));
memset(k6_data, 0, sizeof(k6_data));
}
gssapi_decode_be_om_uint32(SND_SEQ, &seq_number);
if (context_handle->more_flags & LOCAL)
cmp = memcmp(&SND_SEQ[4], "\xff\xff\xff\xff", 4);
else
cmp = memcmp(&SND_SEQ[4], "\x00\x00\x00\x00", 4);
memset(SND_SEQ, 0, sizeof(SND_SEQ));
if (cmp != 0) {
*minor_status = 0;
return GSS_S_BAD_MIC;
}
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
omret = _gssapi_msg_order_check(context_handle->order, seq_number);
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
if (omret)
return omret;
*minor_status = 0;
return GSS_S_COMPLETE;
}
OM_uint32
_gssapi_wrap_arcfour(OM_uint32 * minor_status,
const gss_ctx_id_t context_handle,
int conf_req_flag,
gss_qop_t qop_req,
const gss_buffer_t input_message_buffer,
int * conf_state,
gss_buffer_t output_message_buffer,
krb5_keyblock *key)
{
u_char Klocaldata[16], k6_data[16], *p, *p0;
size_t len, total_len, datalen;
krb5_keyblock Klocal;
krb5_error_code ret;
int32_t seq_number;
if (conf_state)
*conf_state = 0;
datalen = input_message_buffer->length + 1 /* padding */;
len = datalen + GSS_ARCFOUR_WRAP_TOKEN_SIZE;
_gssapi_encap_length(len, &len, &total_len, GSS_KRB5_MECHANISM);
output_message_buffer->length = total_len;
output_message_buffer->value = malloc (total_len);
if (output_message_buffer->value == NULL) {
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
p0 = _gssapi_make_mech_header(output_message_buffer->value,
len,
GSS_KRB5_MECHANISM);
p = p0;
*p++ = 0x02; /* TOK_ID */
*p++ = 0x01;
*p++ = 0x11; /* SGN_ALG */
*p++ = 0x00;
if (conf_req_flag) {
*p++ = 0x10; /* SEAL_ALG */
*p++ = 0x00;
} else {
*p++ = 0xff; /* SEAL_ALG */
*p++ = 0xff;
}
*p++ = 0xff; /* Filler */
*p++ = 0xff;
p = NULL;
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
krb5_auth_con_getlocalseqnumber (gssapi_krb5_context,
context_handle->auth_context,
&seq_number);
gssapi_encode_be_om_uint32(seq_number, p0 + 8);
krb5_auth_con_setlocalseqnumber (gssapi_krb5_context,
context_handle->auth_context,
++seq_number);
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
memset (p0 + 8 + 4,
(context_handle->more_flags & LOCAL) ? 0 : 0xff,
4);
krb5_generate_random_block(p0 + 24, 8); /* fill in Confounder */
/* p points to data */
p = p0 + GSS_ARCFOUR_WRAP_TOKEN_SIZE;
memcpy(p, input_message_buffer->value, input_message_buffer->length);
p[input_message_buffer->length] = 1; /* PADDING */
ret = arcfour_mic_cksum(key, KRB5_KU_USAGE_SEAL,
p0 + 16, 8, /* SGN_CKSUM */
p0, 8, /* TOK_ID, SGN_ALG, SEAL_ALG, Filler */
p0 + 24, 8, /* Confounder */
p0 + GSS_ARCFOUR_WRAP_TOKEN_SIZE,
datalen);
if (ret) {
*minor_status = ret;
gss_release_buffer(minor_status, output_message_buffer);
return GSS_S_FAILURE;
}
{
int i;
Klocal.keytype = key->keytype;
Klocal.keyvalue.data = Klocaldata;
Klocal.keyvalue.length = sizeof(Klocaldata);
for (i = 0; i < 16; i++)
Klocaldata[i] = ((u_char *)key->keyvalue.data)[i] ^ 0xF0;
}
ret = arcfour_mic_key(gssapi_krb5_context, &Klocal,
p0 + 8, 4, /* SND_SEQ */
k6_data, sizeof(k6_data));
memset(Klocaldata, 0, sizeof(Klocaldata));
if (ret) {
gss_release_buffer(minor_status, output_message_buffer);
*minor_status = ret;
return GSS_S_FAILURE;
}
if(conf_req_flag) {
RC4_KEY rc4_key;
RC4_set_key (&rc4_key, sizeof(k6_data), k6_data);
/* XXX ? */
RC4 (&rc4_key, 8 + datalen, p0 + 24, p0 + 24); /* Confounder + data */
memset(&rc4_key, 0, sizeof(rc4_key));
}
memset(k6_data, 0, sizeof(k6_data));
ret = arcfour_mic_key(gssapi_krb5_context, key,
p0 + 16, 8, /* SGN_CKSUM */
k6_data, sizeof(k6_data));
if (ret) {
gss_release_buffer(minor_status, output_message_buffer);
*minor_status = ret;
return GSS_S_FAILURE;
}
{
RC4_KEY rc4_key;
RC4_set_key (&rc4_key, sizeof(k6_data), k6_data);
RC4 (&rc4_key, 8, p0 + 8, p0 + 8); /* SND_SEQ */
memset(&rc4_key, 0, sizeof(rc4_key));
memset(k6_data, 0, sizeof(k6_data));
}
if (conf_state)
*conf_state = conf_req_flag;
*minor_status = 0;
return GSS_S_COMPLETE;
}
OM_uint32 _gssapi_unwrap_arcfour(OM_uint32 *minor_status,
const gss_ctx_id_t context_handle,
const gss_buffer_t input_message_buffer,
gss_buffer_t output_message_buffer,
int *conf_state,
gss_qop_t *qop_state,
krb5_keyblock *key)
{
u_char Klocaldata[16];
krb5_keyblock Klocal;
krb5_error_code ret;
int32_t seq_number;
size_t datalen;
OM_uint32 omret;
char k6_data[16], SND_SEQ[8], Confounder[8];
char cksum_data[8];
u_char *p, *p0;
int cmp;
int conf_flag;
size_t padlen;
if (conf_state)
*conf_state = 0;
if (qop_state)
*qop_state = 0;
p0 = input_message_buffer->value;
omret = _gssapi_verify_mech_header(&p0,
input_message_buffer->length,
GSS_KRB5_MECHANISM);
if (omret)
return omret;
p = p0;
datalen = input_message_buffer->length -
(p - ((u_char *)input_message_buffer->value)) -
GSS_ARCFOUR_WRAP_TOKEN_SIZE;
if (memcmp(p, "\x02\x01", 2) != 0)
return GSS_S_BAD_SIG;
p += 2;
if (memcmp(p, "\x11\x00", 2) != 0) /* SGN_ALG = HMAC MD5 ARCFOUR */
return GSS_S_BAD_SIG;
p += 2;
if (memcmp (p, "\x10\x00", 2) == 0)
conf_flag = 1;
else if (memcmp (p, "\xff\xff", 2) == 0)
conf_flag = 0;
else
return GSS_S_BAD_SIG;
p += 2;
if (memcmp (p, "\xff\xff", 2) != 0)
return GSS_S_BAD_MIC;
p = NULL;
ret = arcfour_mic_key(gssapi_krb5_context, key,
p0 + 16, 8, /* SGN_CKSUM */
k6_data, sizeof(k6_data));
if (ret) {
*minor_status = ret;
return GSS_S_FAILURE;
}
{
RC4_KEY rc4_key;
RC4_set_key (&rc4_key, sizeof(k6_data), k6_data);
RC4 (&rc4_key, 8, p0 + 8, SND_SEQ); /* SND_SEQ */
memset(&rc4_key, 0, sizeof(rc4_key));
memset(k6_data, 0, sizeof(k6_data));
}
gssapi_decode_be_om_uint32(SND_SEQ, &seq_number);
if (context_handle->more_flags & LOCAL)
cmp = memcmp(&SND_SEQ[4], "\xff\xff\xff\xff", 4);
else
cmp = memcmp(&SND_SEQ[4], "\x00\x00\x00\x00", 4);
if (cmp != 0) {
*minor_status = 0;
return GSS_S_BAD_MIC;
}
{
int i;
Klocal.keytype = key->keytype;
Klocal.keyvalue.data = Klocaldata;
Klocal.keyvalue.length = sizeof(Klocaldata);
for (i = 0; i < 16; i++)
Klocaldata[i] = ((u_char *)key->keyvalue.data)[i] ^ 0xF0;
}
ret = arcfour_mic_key(gssapi_krb5_context, &Klocal,
SND_SEQ, 4,
k6_data, sizeof(k6_data));
memset(Klocaldata, 0, sizeof(Klocaldata));
if (ret) {
*minor_status = ret;
return GSS_S_FAILURE;
}
output_message_buffer->value = malloc(datalen);
if (output_message_buffer->value == NULL) {
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
output_message_buffer->length = datalen;
if(conf_flag) {
RC4_KEY rc4_key;
RC4_set_key (&rc4_key, sizeof(k6_data), k6_data);
RC4 (&rc4_key, 8, p0 + 24, Confounder); /* Confounder */
RC4 (&rc4_key, datalen, p0 + GSS_ARCFOUR_WRAP_TOKEN_SIZE,
output_message_buffer->value);
memset(&rc4_key, 0, sizeof(rc4_key));
} else {
memcpy(Confounder, p0 + 24, 8); /* Confounder */
memcpy(output_message_buffer->value,
p0 + GSS_ARCFOUR_WRAP_TOKEN_SIZE,
datalen);
}
memset(k6_data, 0, sizeof(k6_data));
ret = _gssapi_verify_pad(output_message_buffer, datalen, &padlen);
if (ret) {
gss_release_buffer(minor_status, output_message_buffer);
*minor_status = 0;
return ret;
}
output_message_buffer->length -= padlen;
ret = arcfour_mic_cksum(key, KRB5_KU_USAGE_SEAL,
cksum_data, sizeof(cksum_data),
p0, 8,
Confounder, sizeof(Confounder),
output_message_buffer->value,
output_message_buffer->length + padlen);
if (ret) {
gss_release_buffer(minor_status, output_message_buffer);
*minor_status = ret;
return GSS_S_FAILURE;
}
cmp = memcmp(cksum_data, p0 + 16, 8); /* SGN_CKSUM */
if (cmp) {
gss_release_buffer(minor_status, output_message_buffer);
*minor_status = 0;
return GSS_S_BAD_MIC;
}
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
omret = _gssapi_msg_order_check(context_handle->order, seq_number);
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
if (omret)
return omret;
if (conf_state)
*conf_state = conf_flag;
*minor_status = 0;
return GSS_S_COMPLETE;
}