gss_krb5_seal.c

  1/*
  2 *  linux/net/sunrpc/gss_krb5_seal.c
  3 *
  4 *  Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5seal.c
  5 *
  6 *  Copyright (c) 2000-2008 The Regents of the University of Michigan.
  7 *  All rights reserved.
  8 *
  9 *  Andy Adamson	<andros@umich.edu>
 10 *  J. Bruce Fields	<bfields@umich.edu>
 11 */
 12
 13/*
 14 * Copyright 1993 by OpenVision Technologies, Inc.
 15 *
 16 * Permission to use, copy, modify, distribute, and sell this software
 17 * and its documentation for any purpose is hereby granted without fee,
 18 * provided that the above copyright notice appears in all copies and
 19 * that both that copyright notice and this permission notice appear in
 20 * supporting documentation, and that the name of OpenVision not be used
 21 * in advertising or publicity pertaining to distribution of the software
 22 * without specific, written prior permission. OpenVision makes no
 23 * representations about the suitability of this software for any
 24 * purpose.  It is provided "as is" without express or implied warranty.
 25 *
 26 * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 27 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 28 * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 29 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
 30 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 31 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 32 * PERFORMANCE OF THIS SOFTWARE.
 33 */
 34
 35/*
 36 * Copyright (C) 1998 by the FundsXpress, INC.
 37 *
 38 * All rights reserved.
 39 *
 40 * Export of this software from the United States of America may require
 41 * a specific license from the United States Government.  It is the
 42 * responsibility of any person or organization contemplating export to
 43 * obtain such a license before exporting.
 44 *
 45 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
 46 * distribute this software and its documentation for any purpose and
 47 * without fee is hereby granted, provided that the above copyright
 48 * notice appear in all copies and that both that copyright notice and
 49 * this permission notice appear in supporting documentation, and that
 50 * the name of FundsXpress. not be used in advertising or publicity pertaining
 51 * to distribution of the software without specific, written prior
 52 * permission.  FundsXpress makes no representations about the suitability of
 53 * this software for any purpose.  It is provided "as is" without express
 54 * or implied warranty.
 55 *
 56 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 57 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 58 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 59 */
 60
 61#include <linux/types.h>
 62#include <linux/jiffies.h>
 63#include <linux/sunrpc/gss_krb5.h>
 64#include <linux/random.h>
 65#include <linux/crypto.h>
 66#include <linux/atomic.h>
 67
 68#include "gss_krb5_internal.h"
 69
 70#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 71# define RPCDBG_FACILITY        RPCDBG_AUTH
 72#endif
 73
 74static void *
 75setup_token_v2(struct krb5_ctx *ctx, struct xdr_netobj *token)
 76{
 77	u16 *ptr;
 78	void *krb5_hdr;
 79	u8 *p, flags = 0x00;
 80
 81	if ((ctx->flags & KRB5_CTX_FLAG_INITIATOR) == 0)
 82		flags |= 0x01;
 83	if (ctx->flags & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY)
 84		flags |= 0x04;
 85
 86	/* Per rfc 4121, sec 4.2.6.1, there is no header,
 87	 * just start the token.
 88	 */
 89	krb5_hdr = (u16 *)token->data;
 90	ptr = krb5_hdr;
 91
 92	*ptr++ = KG2_TOK_MIC;
 93	p = (u8 *)ptr;
 94	*p++ = flags;
 95	*p++ = 0xff;
 96	ptr = (u16 *)p;
 97	*ptr++ = 0xffff;
 98	*ptr = 0xffff;
 99
100	token->len = GSS_KRB5_TOK_HDR_LEN + ctx->gk5e->cksumlength;
101	return krb5_hdr;
102}
103
104u32
105gss_krb5_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text,
106		    struct xdr_netobj *token)
107{
108	struct crypto_ahash *tfm = ctx->initiate ?
109				   ctx->initiator_sign : ctx->acceptor_sign;
110	struct xdr_netobj cksumobj = {
111		.len =	ctx->gk5e->cksumlength,
112	};
113	__be64 seq_send_be64;
114	void *krb5_hdr;
115	time64_t now;
116
117	dprintk("RPC:       %s\n", __func__);
118
119	krb5_hdr = setup_token_v2(ctx, token);
120
121	/* Set up the sequence number. Now 64-bits in clear
122	 * text and w/o direction indicator */
123	seq_send_be64 = cpu_to_be64(atomic64_fetch_inc(&ctx->seq_send64));
124	memcpy(krb5_hdr + 8, (char *) &seq_send_be64, 8);
125
126	cksumobj.data = krb5_hdr + GSS_KRB5_TOK_HDR_LEN;
127	if (gss_krb5_checksum(tfm, krb5_hdr, GSS_KRB5_TOK_HDR_LEN,
128			      text, 0, &cksumobj))
129		return GSS_S_FAILURE;
130
131	now = ktime_get_real_seconds();
132	return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
133}