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/*
Unix SMB/CIFS implementation.
module to store/fetch session keys for the schannel server
Copyright (C) Andrew Tridgell 2004
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
/* a reasonable amount of time to keep credentials live */
#define SCHANNEL_CREDENTIALS_EXPIRY 600
/*
connect to the schannel ldb
*/
static struct ldb_wrap *schannel_db_connect(TALLOC_CTX *mem_ctx)
{
char *path;
struct ldb_wrap *ldb;
path = lock_path(mem_ctx, "schannel.ldb");
if (!path) {
return NULL;
}
ldb = ldb_wrap_connect(mem_ctx, path, 0, NULL);
if (!ldb) {
return NULL;
}
ldb_set_alloc(ldb->ldb, talloc_realloc_fn, mem_ctx);
return ldb;
}
/*
remember an established session key for a netr server authentication
use a simple ldb structure
*/
NTSTATUS schannel_store_session_key(TALLOC_CTX *mem_ctx,
const char *computer_name,
struct creds_CredentialState *creds)
{
struct ldb_wrap *ldb;
struct ldb_message msg;
struct ldb_val val, seed;
char *s = NULL;
time_t expiry = time(NULL) + SCHANNEL_CREDENTIALS_EXPIRY;
int ret;
ldb = schannel_db_connect(mem_ctx);
if (ldb == NULL) {
return NT_STATUS_NO_MEMORY;
}
asprintf(&s, "%u", (unsigned int)expiry);
if (s == NULL) {
talloc_free(ldb);
return NT_STATUS_NO_MEMORY;
}
ZERO_STRUCT(msg);
msg.dn = talloc_strdup(mem_ctx, computer_name);
if (msg.dn == NULL) {
talloc_free(ldb);
return NT_STATUS_NO_MEMORY;
}
val.data = creds->session_key;
val.length = sizeof(creds->session_key);
seed.data = creds->seed.data;
seed.length = sizeof(creds->seed.data);
ldb_msg_add_value(ldb->ldb, &msg, "sessionKey", &val);
ldb_msg_add_value(ldb->ldb, &msg, "seed", &seed);
ldb_msg_add_string(ldb->ldb, &msg, "expiry", s);
ldb_delete(ldb->ldb, msg.dn);
ret = ldb_add(ldb->ldb, &msg);
if (ret != 0) {
DEBUG(0,("Unable to add %s to session key db - %s\n",
msg.dn, ldb_errstring(ldb->ldb)));
talloc_free(ldb);
return NT_STATUS_INTERNAL_DB_CORRUPTION;
}
talloc_free(ldb);
return NT_STATUS_OK;
}
/*
read back a credentials back for a computer
*/
NTSTATUS schannel_fetch_session_key(TALLOC_CTX *mem_ctx,
const char *computer_name,
struct creds_CredentialState *creds)
{
struct ldb_wrap *ldb;
time_t expiry;
struct ldb_message **res;
int ret;
const struct ldb_val *val;
char *expr=NULL;
ZERO_STRUCTP(creds);
ldb = schannel_db_connect(mem_ctx);
if (ldb == NULL) {
return NT_STATUS_NO_MEMORY;
}
expr = talloc_asprintf(mem_ctx, "(dn=%s)", computer_name);
if (expr == NULL) {
talloc_free(ldb);
return NT_STATUS_NO_MEMORY;
}
ret = ldb_search(ldb->ldb, NULL, LDB_SCOPE_SUBTREE, expr, NULL, &res);
if (ret != 1) {
talloc_free(ldb);
return NT_STATUS_INVALID_HANDLE;
}
expiry = ldb_msg_find_uint(res[0], "expiry", 0);
if (expiry < time(NULL)) {
DEBUG(1,("schannel: attempt to use expired session key for %s\n", computer_name));
talloc_free(ldb);
return NT_STATUS_INVALID_HANDLE;
}
val = ldb_msg_find_ldb_val(res[0], "sessionKey");
if (val == NULL || val->length != 16) {
talloc_free(ldb);
return NT_STATUS_INVALID_HANDLE;
}
memcpy(creds->session_key, val->data, 16);
val = ldb_msg_find_ldb_val(res[0], "seed");
if (val == NULL || val->length != 8) {
talloc_free(ldb);
return NT_STATUS_INVALID_HANDLE;
}
memcpy(creds->seed.data, val->data, 8);
talloc_free(ldb);
return NT_STATUS_OK;
}
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