1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Implementations of the security context functions.
4 *
5 * Author: Ondrej Mosnacek <omosnacek@gmail.com>
6 * Copyright (C) 2020 Red Hat, Inc.
7 */
8
9 #include <linux/jhash.h>
10
11 #include "context.h"
12 #include "mls.h"
13
14 u32 context_compute_hash(const struct context *c)
15 {
16 u32 hash = 0;
17
18 /*
19 * If a context is invalid, it will always be represented by a
20 * context struct with only the len & str set (and vice versa)
21 * under a given policy. Since context structs from different
22 * policies should never meet, it is safe to hash valid and
23 * invalid contexts differently. The context_cmp() function
24 * already operates under the same assumption.
25 */
26 if (c->len)
27 return full_name_hash(NULL, c->str, c->len);
28
29 hash = jhash_3words(c->user, c->role, c->type, hash);
30 hash = mls_range_hash(&c->range, hash);
31 return hash;
32 }
33
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