OpenBSD-4.6/kerberosV/src/lib/gssapi/wrap.c
/*
* 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 "gssapi_locl.h"
RCSID("$KTH: wrap.c,v 1.31 2005/01/05 02:52:12 lukeh Exp $");
OM_uint32
gss_krb5_get_subkey(const gss_ctx_id_t context_handle,
krb5_keyblock **key)
{
krb5_keyblock *skey = NULL;
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
if (context_handle->more_flags & LOCAL) {
krb5_auth_con_getremotesubkey(gssapi_krb5_context,
context_handle->auth_context,
&skey);
} else {
krb5_auth_con_getlocalsubkey(gssapi_krb5_context,
context_handle->auth_context,
&skey);
}
/*
* Only use the initiator subkey or ticket session key if
* an acceptor subkey was not required.
*/
if (skey == NULL &&
(context_handle->more_flags & ACCEPTOR_SUBKEY) == 0) {
if (context_handle->more_flags & LOCAL) {
krb5_auth_con_getlocalsubkey(gssapi_krb5_context,
context_handle->auth_context,
&skey);
} else {
krb5_auth_con_getremotesubkey(gssapi_krb5_context,
context_handle->auth_context,
&skey);
}
if(skey == NULL)
krb5_auth_con_getkey(gssapi_krb5_context,
context_handle->auth_context,
&skey);
}
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
if(skey == NULL)
return GSS_KRB5_S_KG_NO_SUBKEY; /* XXX */
*key = skey;
return 0;
}
static OM_uint32
sub_wrap_size (
OM_uint32 req_output_size,
OM_uint32 * max_input_size,
int blocksize,
int extrasize
)
{
size_t len, total_len;
len = 8 + req_output_size + blocksize + extrasize;
gssapi_krb5_encap_length(len, &len, &total_len, GSS_KRB5_MECHANISM);
total_len -= req_output_size; /* token length */
if (total_len < req_output_size) {
*max_input_size = (req_output_size - total_len);
(*max_input_size) &= (~(OM_uint32)(blocksize - 1));
} else {
*max_input_size = 0;
}
return GSS_S_COMPLETE;
}
OM_uint32
gss_wrap_size_limit (
OM_uint32 * minor_status,
const gss_ctx_id_t context_handle,
int conf_req_flag,
gss_qop_t qop_req,
OM_uint32 req_output_size,
OM_uint32 * max_input_size
)
{
krb5_keyblock *key;
OM_uint32 ret;
krb5_keytype keytype;
ret = gss_krb5_get_subkey(context_handle, &key);
if (ret) {
gssapi_krb5_set_error_string ();
*minor_status = ret;
return GSS_S_FAILURE;
}
krb5_enctype_to_keytype (gssapi_krb5_context, key->keytype, &keytype);
switch (keytype) {
case KEYTYPE_DES :
case KEYTYPE_ARCFOUR:
case KEYTYPE_ARCFOUR_56:
ret = sub_wrap_size(req_output_size, max_input_size, 8, 22);
break;
case KEYTYPE_DES3 :
ret = sub_wrap_size(req_output_size, max_input_size, 8, 34);
break;
default :
ret = _gssapi_wrap_size_cfx(minor_status, context_handle,
conf_req_flag, qop_req,
req_output_size, max_input_size, key);
break;
}
krb5_free_keyblock (gssapi_krb5_context, key);
*minor_status = 0;
return ret;
}
static OM_uint32
wrap_des
(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 *p;
MD5_CTX md5;
u_char hash[16];
DES_key_schedule schedule;
DES_cblock deskey;
DES_cblock zero;
int i;
int32_t seq_number;
size_t len, total_len, padlength, datalen;
padlength = 8 - (input_message_buffer->length % 8);
datalen = input_message_buffer->length + padlength + 8;
len = datalen + 22;
gssapi_krb5_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;
}
p = gssapi_krb5_make_header(output_message_buffer->value,
len,
"\x02\x01", /* TOK_ID */
GSS_KRB5_MECHANISM);
/* SGN_ALG */
memcpy (p, "\x00\x00", 2);
p += 2;
/* SEAL_ALG */
if(conf_req_flag)
memcpy (p, "\x00\x00", 2);
else
memcpy (p, "\xff\xff", 2);
p += 2;
/* Filler */
memcpy (p, "\xff\xff", 2);
p += 2;
/* fill in later */
memset (p, 0, 16);
p += 16;
/* confounder + data + pad */
krb5_generate_random_block(p, 8);
memcpy (p + 8, input_message_buffer->value,
input_message_buffer->length);
memset (p + 8 + input_message_buffer->length, padlength, padlength);
/* checksum */
MD5_Init (&md5);
MD5_Update (&md5, p - 24, 8);
MD5_Update (&md5, p, datalen);
MD5_Final (hash, &md5);
memset (&zero, 0, sizeof(zero));
memcpy (&deskey, key->keyvalue.data, sizeof(deskey));
DES_set_key (&deskey, &schedule);
DES_cbc_cksum ((void *)hash, (void *)hash, sizeof(hash),
&schedule, &zero);
memcpy (p - 8, hash, 8);
/* sequence number */
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
krb5_auth_con_getlocalseqnumber (gssapi_krb5_context,
context_handle->auth_context,
&seq_number);
p -= 16;
p[0] = (seq_number >> 0) & 0xFF;
p[1] = (seq_number >> 8) & 0xFF;
p[2] = (seq_number >> 16) & 0xFF;
p[3] = (seq_number >> 24) & 0xFF;
memset (p + 4,
(context_handle->more_flags & LOCAL) ? 0 : 0xFF,
4);
DES_set_key (&deskey, &schedule);
DES_cbc_encrypt ((void *)p, (void *)p, 8,
&schedule, (DES_cblock *)(p + 8), DES_ENCRYPT);
krb5_auth_con_setlocalseqnumber (gssapi_krb5_context,
context_handle->auth_context,
++seq_number);
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
/* encrypt the data */
p += 16;
if(conf_req_flag) {
memcpy (&deskey, key->keyvalue.data, sizeof(deskey));
for (i = 0; i < sizeof(deskey); ++i)
deskey[i] ^= 0xf0;
DES_set_key (&deskey, &schedule);
memset (&zero, 0, sizeof(zero));
DES_cbc_encrypt ((void *)p,
(void *)p,
datalen,
&schedule,
&zero,
DES_ENCRYPT);
}
memset (deskey, 0, sizeof(deskey));
memset (&schedule, 0, sizeof(schedule));
if(conf_state != NULL)
*conf_state = conf_req_flag;
*minor_status = 0;
return GSS_S_COMPLETE;
}
static OM_uint32
wrap_des3
(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 *p;
u_char seq[8];
int32_t seq_number;
size_t len, total_len, padlength, datalen;
u_int32_t ret;
krb5_crypto crypto;
Checksum cksum;
krb5_data encdata;
padlength = 8 - (input_message_buffer->length % 8);
datalen = input_message_buffer->length + padlength + 8;
len = datalen + 34;
gssapi_krb5_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;
}
p = gssapi_krb5_make_header(output_message_buffer->value,
len,
"\x02\x01", /* TOK_ID */
GSS_KRB5_MECHANISM);
/* SGN_ALG */
memcpy (p, "\x04\x00", 2); /* HMAC SHA1 DES3-KD */
p += 2;
/* SEAL_ALG */
if(conf_req_flag)
memcpy (p, "\x02\x00", 2); /* DES3-KD */
else
memcpy (p, "\xff\xff", 2);
p += 2;
/* Filler */
memcpy (p, "\xff\xff", 2);
p += 2;
/* calculate checksum (the above + confounder + data + pad) */
memcpy (p + 20, p - 8, 8);
krb5_generate_random_block(p + 28, 8);
memcpy (p + 28 + 8, input_message_buffer->value,
input_message_buffer->length);
memset (p + 28 + 8 + input_message_buffer->length, padlength, padlength);
ret = krb5_crypto_init(gssapi_krb5_context, key, 0, &crypto);
if (ret) {
gssapi_krb5_set_error_string ();
free (output_message_buffer->value);
*minor_status = ret;
return GSS_S_FAILURE;
}
ret = krb5_create_checksum (gssapi_krb5_context,
crypto,
KRB5_KU_USAGE_SIGN,
0,
p + 20,
datalen + 8,
&cksum);
krb5_crypto_destroy (gssapi_krb5_context, crypto);
if (ret) {
gssapi_krb5_set_error_string ();
free (output_message_buffer->value);
*minor_status = ret;
return GSS_S_FAILURE;
}
/* zero out SND_SEQ + SGN_CKSUM in case */
memset (p, 0, 28);
memcpy (p + 8, cksum.checksum.data, cksum.checksum.length);
free_Checksum (&cksum);
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
/* sequence number */
krb5_auth_con_getlocalseqnumber (gssapi_krb5_context,
context_handle->auth_context,
&seq_number);
seq[0] = (seq_number >> 0) & 0xFF;
seq[1] = (seq_number >> 8) & 0xFF;
seq[2] = (seq_number >> 16) & 0xFF;
seq[3] = (seq_number >> 24) & 0xFF;
memset (seq + 4,
(context_handle->more_flags & LOCAL) ? 0 : 0xFF,
4);
ret = krb5_crypto_init(gssapi_krb5_context, key, ETYPE_DES3_CBC_NONE,
&crypto);
if (ret) {
free (output_message_buffer->value);
*minor_status = ret;
return GSS_S_FAILURE;
}
{
DES_cblock ivec;
memcpy (&ivec, p + 8, 8);
ret = krb5_encrypt_ivec (gssapi_krb5_context,
crypto,
KRB5_KU_USAGE_SEQ,
seq, 8, &encdata,
&ivec);
}
krb5_crypto_destroy (gssapi_krb5_context, crypto);
if (ret) {
gssapi_krb5_set_error_string ();
free (output_message_buffer->value);
*minor_status = ret;
return GSS_S_FAILURE;
}
assert (encdata.length == 8);
memcpy (p, encdata.data, encdata.length);
krb5_data_free (&encdata);
krb5_auth_con_setlocalseqnumber (gssapi_krb5_context,
context_handle->auth_context,
++seq_number);
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
/* encrypt the data */
p += 28;
if(conf_req_flag) {
krb5_data tmp;
ret = krb5_crypto_init(gssapi_krb5_context, key,
ETYPE_DES3_CBC_NONE, &crypto);
if (ret) {
gssapi_krb5_set_error_string ();
free (output_message_buffer->value);
*minor_status = ret;
return GSS_S_FAILURE;
}
ret = krb5_encrypt(gssapi_krb5_context, crypto, KRB5_KU_USAGE_SEAL,
p, datalen, &tmp);
krb5_crypto_destroy(gssapi_krb5_context, crypto);
if (ret) {
gssapi_krb5_set_error_string ();
free (output_message_buffer->value);
*minor_status = ret;
return GSS_S_FAILURE;
}
assert (tmp.length == datalen);
memcpy (p, tmp.data, datalen);
krb5_data_free(&tmp);
}
if(conf_state != NULL)
*conf_state = conf_req_flag;
*minor_status = 0;
return GSS_S_COMPLETE;
}
OM_uint32 gss_wrap
(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;
OM_uint32 ret;
krb5_keytype keytype;
ret = gss_krb5_get_subkey(context_handle, &key);
if (ret) {
gssapi_krb5_set_error_string ();
*minor_status = ret;
return GSS_S_FAILURE;
}
krb5_enctype_to_keytype (gssapi_krb5_context, key->keytype, &keytype);
switch (keytype) {
case KEYTYPE_DES :
ret = wrap_des (minor_status, context_handle, conf_req_flag,
qop_req, input_message_buffer, conf_state,
output_message_buffer, key);
break;
case KEYTYPE_DES3 :
ret = wrap_des3 (minor_status, context_handle, conf_req_flag,
qop_req, input_message_buffer, conf_state,
output_message_buffer, key);
break;
case KEYTYPE_ARCFOUR:
case KEYTYPE_ARCFOUR_56:
ret = _gssapi_wrap_arcfour (minor_status, context_handle, conf_req_flag,
qop_req, input_message_buffer, conf_state,
output_message_buffer, key);
break;
default :
ret = _gssapi_wrap_cfx (minor_status, context_handle, conf_req_flag,
qop_req, input_message_buffer, conf_state,
output_message_buffer, key);
break;
}
krb5_free_keyblock (gssapi_krb5_context, key);
return ret;
}