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/*
* COPYRIGHT (c) 2006
* The Regents of the University of Michigan
* ALL RIGHTS RESERVED
*
* Permission is granted to use, copy, create derivative works
* and redistribute this software and such derivative works
* for any purpose, so long as the name of The University of
* Michigan is not used in any advertising or publicity
* pertaining to the use of distribution of this software
* without specific, written prior authorization. If the
* above copyright notice or any other identification of the
* University of Michigan is included in any copy of any
* portion of this software, then the disclaimer below must
* also be included.
*
* THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION
* FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY
* PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF
* MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
* WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
* REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE
* FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR
* CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING
* OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
* IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGES.
*/
#include "config.h"
#ifdef HAVE_LUCID_CONTEXT_SUPPORT
/*
* Newer versions of MIT and Heimdal have lucid context support.
* We can use common code if it is supported.
*/
#include <stdio.h>
#include <syslog.h>
#include <string.h>
#include "gss_util.h"
#include "gss_oids.h"
#include "err_util.h"
#include "context.h"
#include <krb5.h>
#include <gssapi/gssapi.h>
#ifndef OM_uint64
typedef uint64_t OM_uint64;
#endif
#include <gssapi/gssapi_krb5.h>
static int
write_lucid_keyblock(char **p, char *end, gss_krb5_lucid_key_t *key)
{
gss_buffer_desc tmp;
if (WRITE_BYTES(p, end, key->type)) return -1;
tmp.length = key->length;
tmp.value = key->data;
if (write_buffer(p, end, &tmp)) return -1;
return 0;
}
static int
prepare_krb5_rfc1964_buffer(gss_krb5_lucid_context_v1_t *lctx,
gss_buffer_desc *buf)
{
char *p, *end;
static int constant_zero = 0;
unsigned char fakeseed[16];
uint32_t word_send_seq;
gss_krb5_lucid_key_t enc_key;
int i;
char *skd, *dkd;
gss_buffer_desc fakeoid;
/*
* The new Kerberos interface to get the gss context
* does not include the seed or seed_init fields
* because we never really use them. But for now,
* send down a fake buffer so we can use the same
* interface to the kernel.
*/
memset(&enc_key, 0, sizeof(enc_key));
memset(&fakeoid, 0, sizeof(fakeoid));
if (!(buf->value = calloc(1, MAX_CTX_LEN)))
goto out_err;
p = buf->value;
end = buf->value + MAX_CTX_LEN;
if (WRITE_BYTES(&p, end, lctx->initiate)) goto out_err;
/* seed_init and seed not used by kernel anyway */
if (WRITE_BYTES(&p, end, constant_zero)) goto out_err;
if (write_bytes(&p, end, &fakeseed, 16)) goto out_err;
if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.sign_alg)) goto out_err;
if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.seal_alg)) goto out_err;
if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
word_send_seq = lctx->send_seq; /* XXX send_seq is 64-bit */
if (WRITE_BYTES(&p, end, word_send_seq)) goto out_err;
if (write_oid(&p, end, &krb5oid)) goto out_err;
#ifdef HAVE_HEIMDAL
/*
* The kernel gss code expects des-cbc-raw for all flavors of des.
* The keytype from MIT has this type, but Heimdal does not.
* Force the Heimdal keytype to 4 (des-cbc-raw).
* Note that the rfc1964 version only supports DES enctypes.
*/
if (lctx->rfc1964_kd.ctx_key.type != 4) {
printerr(1, "prepare_krb5_rfc1964_buffer: "
"overriding heimdal keytype (%d => %d)\n",
lctx->rfc1964_kd.ctx_key.type, 4);
lctx->rfc1964_kd.ctx_key.type = 4;
}
#endif
printerr(2, "prepare_krb5_rfc1964_buffer: serializing keys with "
"enctype %d and length %d\n",
lctx->rfc1964_kd.ctx_key.type,
lctx->rfc1964_kd.ctx_key.length);
/* derive the encryption key and copy it into buffer */
enc_key.type = lctx->rfc1964_kd.ctx_key.type;
enc_key.length = lctx->rfc1964_kd.ctx_key.length;
if ((enc_key.data = calloc(1, enc_key.length)) == NULL)
goto out_err;
skd = (char *) lctx->rfc1964_kd.ctx_key.data;
dkd = (char *) enc_key.data;
for (i = 0; i < enc_key.length; i++)
dkd[i] = skd[i] ^ 0xf0;
if (write_lucid_keyblock(&p, end, &enc_key)) {
free(enc_key.data);
goto out_err;
}
free(enc_key.data);
if (write_lucid_keyblock(&p, end, &lctx->rfc1964_kd.ctx_key))
goto out_err;
buf->length = p - (char *)buf->value;
return 0;
out_err:
printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
if (buf->value) free(buf->value);
buf->length = 0;
if (enc_key.data) free(enc_key.data);
return -1;
}
static int
prepare_krb5_rfc_cfx_buffer(gss_krb5_lucid_context_v1_t *lctx,
gss_buffer_desc *buf)
{
printerr(0, "ERROR: prepare_krb5_rfc_cfx_buffer: not implemented\n");
return -1;
}
int
serialize_krb5_ctx(gss_ctx_id_t ctx, gss_buffer_desc *buf)
{
OM_uint32 maj_stat, min_stat;
void *return_ctx = 0;
OM_uint32 vers;
gss_krb5_lucid_context_v1_t *lctx = 0;
int retcode = 0;
printerr(2, "DEBUG: serialize_krb5_ctx: lucid version!\n");
maj_stat = gss_export_lucid_sec_context(&min_stat, &ctx,
1, &return_ctx);
if (maj_stat != GSS_S_COMPLETE) {
pgsserr("gss_export_lucid_sec_context",
maj_stat, min_stat, &krb5oid);
goto out_err;
}
/* Check the version returned, we only support v1 right now */
vers = ((gss_krb5_lucid_context_version_t *)return_ctx)->version;
switch (vers) {
case 1:
lctx = (gss_krb5_lucid_context_v1_t *) return_ctx;
break;
default:
printerr(0, "ERROR: unsupported lucid sec context version %d\n",
vers);
goto out_err;
break;
}
/* Now lctx points to a lucid context that we can send down to kernel */
if (lctx->protocol == 0)
retcode = prepare_krb5_rfc1964_buffer(lctx, buf);
else
retcode = prepare_krb5_rfc_cfx_buffer(lctx, buf);
maj_stat = gss_free_lucid_sec_context(&min_stat, ctx, return_ctx);
if (maj_stat != GSS_S_COMPLETE) {
pgsserr("gss_export_lucid_sec_context",
maj_stat, min_stat, &krb5oid);
printerr(0, "WARN: failed to free lucid sec context\n");
}
if (retcode) {
printerr(1, "serialize_krb5_ctx: prepare_krb5_*_buffer "
"failed (retcode = %d)\n", retcode);
goto out_err;
}
return 0;
out_err:
printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
return -1;
}
#endif /* HAVE_LUCID_CONTEXT_SUPPORT */
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