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/*
* Copyright (c) 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("$Id: sequence.c,v 1.5 2005/04/27 17:49:43 lha Exp $");
#define DEFAULT_JITTER_WINDOW 20
struct gss_msg_order {
OM_uint32 flags;
OM_uint32 start;
OM_uint32 length;
OM_uint32 jitter_window;
OM_uint32 first_seq;
OM_uint32 elem[1];
};
/*
*
*/
OM_uint32
_gssapi_msg_order_create(OM_uint32 *minor_status,
struct gss_msg_order **o,
OM_uint32 flags,
OM_uint32 seq_num,
OM_uint32 jitter_window,
int use_64)
{
size_t len;
if (jitter_window == 0)
jitter_window = DEFAULT_JITTER_WINDOW;
len = jitter_window * sizeof((*o)->elem[0]);
len += sizeof(**o);
len -= sizeof((*o)->elem[0]);
*o = malloc(len);
if (*o == NULL) {
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
memset(*o, 0, len);
(*o)->flags = flags;
(*o)->length = 0;
(*o)->first_seq = seq_num;
(*o)->jitter_window = jitter_window;
(*o)->elem[0] = seq_num - 1;
*minor_status = 0;
return GSS_S_COMPLETE;
}
OM_uint32
_gssapi_msg_order_destroy(struct gss_msg_order **m)
{
free(*m);
*m = NULL;
return GSS_S_COMPLETE;
}
static void
elem_set(struct gss_msg_order *o, unsigned int slot, OM_uint32 val)
{
o->elem[slot % o->jitter_window] = val;
}
static void
elem_insert(struct gss_msg_order *o,
unsigned int after_slot,
OM_uint32 seq_num)
{
assert(o->jitter_window > after_slot);
if (o->length > after_slot)
memmove(&o->elem[after_slot + 1], &o->elem[after_slot],
(o->length - after_slot - 1) * sizeof(o->elem[0]));
elem_set(o, after_slot, seq_num);
if (o->length < o->jitter_window)
o->length++;
}
/* rule 1: expected sequence number */
/* rule 2: > expected sequence number */
/* rule 3: seqnum < seqnum(first) */
/* rule 4+5: seqnum in [seqnum(first),seqnum(last)] */
OM_uint32
_gssapi_msg_order_check(struct gss_msg_order *o, OM_uint32 seq_num)
{
OM_uint32 r;
int i;
if (o == NULL)
return GSS_S_COMPLETE;
if ((o->flags & (GSS_C_REPLAY_FLAG|GSS_C_SEQUENCE_FLAG)) == 0)
return GSS_S_COMPLETE;
/* check if the packet is the next in order */
if (o->elem[0] == seq_num - 1) {
elem_insert(o, 0, seq_num);
return GSS_S_COMPLETE;
}
r = (o->flags & (GSS_C_REPLAY_FLAG|GSS_C_SEQUENCE_FLAG))==GSS_C_REPLAY_FLAG;
/* sequence number larger then largest sequence number
* or smaller then the first sequence number */
if (seq_num > o->elem[0]
|| seq_num < o->first_seq
|| o->length == 0)
{
elem_insert(o, 0, seq_num);
if (r) {
return GSS_S_COMPLETE;
} else {
return GSS_S_GAP_TOKEN;
}
}
assert(o->length > 0);
/* sequence number smaller the first sequence number */
if (seq_num < o->elem[o->length - 1]) {
if (r)
return(GSS_S_OLD_TOKEN);
else
return(GSS_S_UNSEQ_TOKEN);
}
if (seq_num == o->elem[o->length - 1]) {
return GSS_S_DUPLICATE_TOKEN;
}
for (i = 0; i < o->length - 1; i++) {
if (o->elem[i] == seq_num)
return GSS_S_DUPLICATE_TOKEN;
if (o->elem[i + 1] < seq_num && o->elem[i] < seq_num) {
elem_insert(o, i, seq_num);
if (r)
return GSS_S_COMPLETE;
else
return GSS_S_UNSEQ_TOKEN;
}
}
return GSS_S_FAILURE;
}
OM_uint32
_gssapi_msg_order_f(OM_uint32 flags)
{
return flags & (GSS_C_SEQUENCE_FLAG|GSS_C_REPLAY_FLAG);
}
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