11da177e4SLinus Torvalds /*
21da177e4SLinus Torvalds * linux/net/sunrpc/gss_krb5_unseal.c
31da177e4SLinus Torvalds *
41da177e4SLinus Torvalds * Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5unseal.c
51da177e4SLinus Torvalds *
681d4a433SKevin Coffman * Copyright (c) 2000-2008 The Regents of the University of Michigan.
71da177e4SLinus Torvalds * All rights reserved.
81da177e4SLinus Torvalds *
91da177e4SLinus Torvalds * Andy Adamson <andros@umich.edu>
101da177e4SLinus Torvalds */
111da177e4SLinus Torvalds
121da177e4SLinus Torvalds /*
131da177e4SLinus Torvalds * Copyright 1993 by OpenVision Technologies, Inc.
141da177e4SLinus Torvalds *
151da177e4SLinus Torvalds * Permission to use, copy, modify, distribute, and sell this software
161da177e4SLinus Torvalds * and its documentation for any purpose is hereby granted without fee,
171da177e4SLinus Torvalds * provided that the above copyright notice appears in all copies and
181da177e4SLinus Torvalds * that both that copyright notice and this permission notice appear in
191da177e4SLinus Torvalds * supporting documentation, and that the name of OpenVision not be used
201da177e4SLinus Torvalds * in advertising or publicity pertaining to distribution of the software
211da177e4SLinus Torvalds * without specific, written prior permission. OpenVision makes no
221da177e4SLinus Torvalds * representations about the suitability of this software for any
231da177e4SLinus Torvalds * purpose. It is provided "as is" without express or implied warranty.
241da177e4SLinus Torvalds *
251da177e4SLinus Torvalds * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
261da177e4SLinus Torvalds * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
271da177e4SLinus Torvalds * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
281da177e4SLinus Torvalds * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
291da177e4SLinus Torvalds * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
301da177e4SLinus Torvalds * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
311da177e4SLinus Torvalds * PERFORMANCE OF THIS SOFTWARE.
321da177e4SLinus Torvalds */
331da177e4SLinus Torvalds
341da177e4SLinus Torvalds /*
351da177e4SLinus Torvalds * Copyright (C) 1998 by the FundsXpress, INC.
361da177e4SLinus Torvalds *
371da177e4SLinus Torvalds * All rights reserved.
381da177e4SLinus Torvalds *
391da177e4SLinus Torvalds * Export of this software from the United States of America may require
401da177e4SLinus Torvalds * a specific license from the United States Government. It is the
411da177e4SLinus Torvalds * responsibility of any person or organization contemplating export to
421da177e4SLinus Torvalds * obtain such a license before exporting.
431da177e4SLinus Torvalds *
441da177e4SLinus Torvalds * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
451da177e4SLinus Torvalds * distribute this software and its documentation for any purpose and
461da177e4SLinus Torvalds * without fee is hereby granted, provided that the above copyright
471da177e4SLinus Torvalds * notice appear in all copies and that both that copyright notice and
481da177e4SLinus Torvalds * this permission notice appear in supporting documentation, and that
491da177e4SLinus Torvalds * the name of FundsXpress. not be used in advertising or publicity pertaining
501da177e4SLinus Torvalds * to distribution of the software without specific, written prior
511da177e4SLinus Torvalds * permission. FundsXpress makes no representations about the suitability of
521da177e4SLinus Torvalds * this software for any purpose. It is provided "as is" without express
531da177e4SLinus Torvalds * or implied warranty.
541da177e4SLinus Torvalds *
551da177e4SLinus Torvalds * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
561da177e4SLinus Torvalds * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
571da177e4SLinus Torvalds * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
581da177e4SLinus Torvalds */
591da177e4SLinus Torvalds
602dbe0cacSChuck Lever #include <crypto/algapi.h>
611da177e4SLinus Torvalds #include <linux/types.h>
621da177e4SLinus Torvalds #include <linux/jiffies.h>
631da177e4SLinus Torvalds #include <linux/sunrpc/gss_krb5.h>
641da177e4SLinus Torvalds #include <linux/crypto.h>
651da177e4SLinus Torvalds
662dbe0cacSChuck Lever #include "gss_krb5_internal.h"
672dbe0cacSChuck Lever
68f895b252SJeff Layton #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
691da177e4SLinus Torvalds # define RPCDBG_FACILITY RPCDBG_AUTH
701da177e4SLinus Torvalds #endif
711da177e4SLinus Torvalds
72*e01b2c79SChuck Lever u32
gss_krb5_verify_mic_v2(struct krb5_ctx * ctx,struct xdr_buf * message_buffer,struct xdr_netobj * read_token)73*e01b2c79SChuck Lever gss_krb5_verify_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *message_buffer,
74*e01b2c79SChuck Lever struct xdr_netobj *read_token)
75de9c17ebSKevin Coffman {
762dbe0cacSChuck Lever struct crypto_ahash *tfm = ctx->initiate ?
772dbe0cacSChuck Lever ctx->acceptor_sign : ctx->initiator_sign;
78de9c17ebSKevin Coffman char cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
792dbe0cacSChuck Lever struct xdr_netobj cksumobj = {
802dbe0cacSChuck Lever .len = ctx->gk5e->cksumlength,
812dbe0cacSChuck Lever .data = cksumdata,
822dbe0cacSChuck Lever };
83de9c17ebSKevin Coffman u8 *ptr = read_token->data;
842dbe0cacSChuck Lever __be16 be16_ptr;
852dbe0cacSChuck Lever time64_t now;
86de9c17ebSKevin Coffman u8 flags;
87de9c17ebSKevin Coffman int i;
88de9c17ebSKevin Coffman
89de9c17ebSKevin Coffman dprintk("RPC: %s\n", __func__);
90de9c17ebSKevin Coffman
9190a9b147SJames Ettle memcpy(&be16_ptr, (char *) ptr, 2);
9290a9b147SJames Ettle if (be16_to_cpu(be16_ptr) != KG2_TOK_MIC)
93de9c17ebSKevin Coffman return GSS_S_DEFECTIVE_TOKEN;
94de9c17ebSKevin Coffman
95de9c17ebSKevin Coffman flags = ptr[2];
96de9c17ebSKevin Coffman if ((!ctx->initiate && (flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)) ||
97de9c17ebSKevin Coffman (ctx->initiate && !(flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)))
98de9c17ebSKevin Coffman return GSS_S_BAD_SIG;
99de9c17ebSKevin Coffman
100de9c17ebSKevin Coffman if (flags & KG2_TOKEN_FLAG_SEALED) {
101de9c17ebSKevin Coffman dprintk("%s: token has unexpected sealed flag\n", __func__);
102de9c17ebSKevin Coffman return GSS_S_FAILURE;
103de9c17ebSKevin Coffman }
104de9c17ebSKevin Coffman
105de9c17ebSKevin Coffman for (i = 3; i < 8; i++)
106de9c17ebSKevin Coffman if (ptr[i] != 0xff)
107de9c17ebSKevin Coffman return GSS_S_DEFECTIVE_TOKEN;
108de9c17ebSKevin Coffman
1092dbe0cacSChuck Lever if (gss_krb5_checksum(tfm, ptr, GSS_KRB5_TOK_HDR_LEN,
1102dbe0cacSChuck Lever message_buffer, 0, &cksumobj))
111de9c17ebSKevin Coffman return GSS_S_FAILURE;
112de9c17ebSKevin Coffman
113de9c17ebSKevin Coffman if (memcmp(cksumobj.data, ptr + GSS_KRB5_TOK_HDR_LEN,
114de9c17ebSKevin Coffman ctx->gk5e->cksumlength))
115de9c17ebSKevin Coffman return GSS_S_BAD_SIG;
116de9c17ebSKevin Coffman
117de9c17ebSKevin Coffman /* it got through unscathed. Make sure the context is unexpired */
118294ec5b8SArnd Bergmann now = ktime_get_real_seconds();
119de9c17ebSKevin Coffman if (now > ctx->endtime)
120de9c17ebSKevin Coffman return GSS_S_CONTEXT_EXPIRED;
121de9c17ebSKevin Coffman
1225d6baef9SJ. Bruce Fields /*
1235d6baef9SJ. Bruce Fields * NOTE: the sequence number at ptr + 8 is skipped, rpcsec_gss
1245d6baef9SJ. Bruce Fields * doesn't want it checked; see page 6 of rfc 2203.
1255d6baef9SJ. Bruce Fields */
126de9c17ebSKevin Coffman
127de9c17ebSKevin Coffman return GSS_S_COMPLETE;
128de9c17ebSKevin Coffman }
129