linux/net/sunrpc/auth_gss/gss_krb5_unseal.c
Kevin Coffman 1ac3719a22 gss_krb5: split up functions in preparation of adding new enctypes
Add encryption type to the krb5 context structure and use it to switch
to the correct functions depending on the encryption type.

Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14 15:09:15 -04:00

152 lines
4.8 KiB
C

/*
* linux/net/sunrpc/gss_krb5_unseal.c
*
* Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5unseal.c
*
* Copyright (c) 2000 The Regents of the University of Michigan.
* All rights reserved.
*
* Andy Adamson <andros@umich.edu>
*/
/*
* Copyright 1993 by OpenVision Technologies, Inc.
*
* Permission to use, copy, modify, distribute, and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appears in all copies and
* that both that copyright notice and this permission notice appear in
* supporting documentation, and that the name of OpenVision not be used
* in advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. OpenVision makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
* OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
* USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
* OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/*
* Copyright (C) 1998 by the FundsXpress, INC.
*
* All rights reserved.
*
* Export of this software from the United States of America may require
* a specific license from the United States Government. It is the
* responsibility of any person or organization contemplating export to
* obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of FundsXpress. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. FundsXpress makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#include <linux/types.h>
#include <linux/jiffies.h>
#include <linux/sunrpc/gss_krb5.h>
#include <linux/crypto.h>
#ifdef RPC_DEBUG
# define RPCDBG_FACILITY RPCDBG_AUTH
#endif
/* read_token is a mic token, and message_buffer is the data that the mic was
* supposedly taken over. */
static u32
gss_verify_mic_v1(struct krb5_ctx *ctx,
struct xdr_buf *message_buffer, struct xdr_netobj *read_token)
{
int signalg;
int sealalg;
char cksumdata[16];
struct xdr_netobj md5cksum = {.len = 0, .data = cksumdata};
s32 now;
int direction;
u32 seqnum;
unsigned char *ptr = (unsigned char *)read_token->data;
int bodysize;
dprintk("RPC: krb5_read_token\n");
if (g_verify_token_header(&ctx->mech_used, &bodysize, &ptr,
read_token->len))
return GSS_S_DEFECTIVE_TOKEN;
if ((ptr[0] != ((KG_TOK_MIC_MSG >> 8) & 0xff)) ||
(ptr[1] != (KG_TOK_MIC_MSG & 0xff)))
return GSS_S_DEFECTIVE_TOKEN;
/* XXX sanity-check bodysize?? */
signalg = ptr[2] + (ptr[3] << 8);
if (signalg != SGN_ALG_DES_MAC_MD5)
return GSS_S_DEFECTIVE_TOKEN;
sealalg = ptr[4] + (ptr[5] << 8);
if (sealalg != SEAL_ALG_NONE)
return GSS_S_DEFECTIVE_TOKEN;
if ((ptr[6] != 0xff) || (ptr[7] != 0xff))
return GSS_S_DEFECTIVE_TOKEN;
if (make_checksum("md5", ptr, 8, message_buffer, 0, &md5cksum))
return GSS_S_FAILURE;
if (krb5_encrypt(ctx->seq, NULL, md5cksum.data, md5cksum.data, 16))
return GSS_S_FAILURE;
if (memcmp(md5cksum.data + 8, ptr + GSS_KRB5_TOK_HDR_LEN, 8))
return GSS_S_BAD_SIG;
/* it got through unscathed. Make sure the context is unexpired */
now = get_seconds();
if (now > ctx->endtime)
return GSS_S_CONTEXT_EXPIRED;
/* do sequencing checks */
if (krb5_get_seq_num(ctx->seq, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8, &direction, &seqnum))
return GSS_S_FAILURE;
if ((ctx->initiate && direction != 0xff) ||
(!ctx->initiate && direction != 0))
return GSS_S_BAD_SIG;
return GSS_S_COMPLETE;
}
u32
gss_verify_mic_kerberos(struct gss_ctx *gss_ctx,
struct xdr_buf *message_buffer,
struct xdr_netobj *read_token)
{
struct krb5_ctx *ctx = gss_ctx->internal_ctx_id;
switch (ctx->enctype) {
default:
BUG();
case ENCTYPE_DES_CBC_RAW:
return gss_verify_mic_v1(ctx, message_buffer, read_token);
}
}