linux/net/sunrpc/auth_gss/gss_krb5_seqnum.c

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/*
* linux/net/sunrpc/gss_krb5_seqnum.c
*
* Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/util_seqnum.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.
*/
#include <crypto/skcipher.h>
#include <linux/types.h>
#include <linux/sunrpc/gss_krb5.h>
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
# define RPCDBG_FACILITY RPCDBG_AUTH
#endif
static s32
krb5_make_rc4_seq_num(struct krb5_ctx *kctx, int direction, s32 seqnum,
unsigned char *cksum, unsigned char *buf)
{
struct crypto_sync_skcipher *cipher;
unsigned char *plain;
s32 code;
dprintk("RPC: %s:\n", __func__);
cipher = crypto_alloc_sync_skcipher(kctx->gk5e->encrypt_name, 0, 0);
if (IS_ERR(cipher))
return PTR_ERR(cipher);
plain = kmalloc(8, GFP_NOFS);
if (!plain)
return -ENOMEM;
plain[0] = (unsigned char) ((seqnum >> 24) & 0xff);
plain[1] = (unsigned char) ((seqnum >> 16) & 0xff);
plain[2] = (unsigned char) ((seqnum >> 8) & 0xff);
plain[3] = (unsigned char) ((seqnum >> 0) & 0xff);
plain[4] = direction;
plain[5] = direction;
plain[6] = direction;
plain[7] = direction;
code = krb5_rc4_setup_seq_key(kctx, cipher, cksum);
if (code)
goto out;
code = krb5_encrypt(cipher, cksum, plain, buf, 8);
out:
kfree(plain);
crypto_free_sync_skcipher(cipher);
return code;
}
s32
krb5_make_seq_num(struct krb5_ctx *kctx,
struct crypto_sync_skcipher *key,
int direction,
u32 seqnum,
unsigned char *cksum, unsigned char *buf)
{
unsigned char *plain;
s32 code;
if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC)
return krb5_make_rc4_seq_num(kctx, direction, seqnum,
cksum, buf);
plain = kmalloc(8, GFP_NOFS);
if (!plain)
return -ENOMEM;
plain[0] = (unsigned char) (seqnum & 0xff);
plain[1] = (unsigned char) ((seqnum >> 8) & 0xff);
plain[2] = (unsigned char) ((seqnum >> 16) & 0xff);
plain[3] = (unsigned char) ((seqnum >> 24) & 0xff);
plain[4] = direction;
plain[5] = direction;
plain[6] = direction;
plain[7] = direction;
code = krb5_encrypt(key, cksum, plain, buf, 8);
kfree(plain);
return code;
}
static s32
krb5_get_rc4_seq_num(struct krb5_ctx *kctx, unsigned char *cksum,
unsigned char *buf, int *direction, s32 *seqnum)
{
struct crypto_sync_skcipher *cipher;
unsigned char *plain;
s32 code;
dprintk("RPC: %s:\n", __func__);
cipher = crypto_alloc_sync_skcipher(kctx->gk5e->encrypt_name, 0, 0);
if (IS_ERR(cipher))
return PTR_ERR(cipher);
code = krb5_rc4_setup_seq_key(kctx, cipher, cksum);
if (code)
goto out;
plain = kmalloc(8, GFP_NOFS);
if (!plain) {
code = -ENOMEM;
goto out;
}
code = krb5_decrypt(cipher, cksum, buf, plain, 8);
if (code)
goto out_plain;
if ((plain[4] != plain[5]) || (plain[4] != plain[6])
|| (plain[4] != plain[7])) {
code = (s32)KG_BAD_SEQ;
goto out_plain;
}
*direction = plain[4];
*seqnum = ((plain[0] << 24) | (plain[1] << 16) |
(plain[2] << 8) | (plain[3]));
out_plain:
kfree(plain);
out:
crypto_free_sync_skcipher(cipher);
return code;
}
s32
krb5_get_seq_num(struct krb5_ctx *kctx,
unsigned char *cksum,
unsigned char *buf,
int *direction, u32 *seqnum)
{
s32 code;
unsigned char *plain;
struct crypto_sync_skcipher *key = kctx->seq;
dprintk("RPC: krb5_get_seq_num:\n");
if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC)
return krb5_get_rc4_seq_num(kctx, cksum, buf,
direction, seqnum);
plain = kmalloc(8, GFP_NOFS);
if (!plain)
return -ENOMEM;
if ((code = krb5_decrypt(key, cksum, buf, plain, 8)))
goto out;
if ((plain[4] != plain[5]) || (plain[4] != plain[6]) ||
(plain[4] != plain[7])) {
code = (s32)KG_BAD_SEQ;
goto out;
}
*direction = plain[4];
*seqnum = ((plain[0]) |
(plain[1] << 8) | (plain[2] << 16) | (plain[3] << 24));
out:
kfree(plain);
return code;
}