Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
765cb46a JM |
2 | /* |
3 | * AES-128-CMAC with TLen 16 for IEEE 802.11w BIP | |
4 | * Copyright 2008, Jouni Malinen <j@w1.fi> | |
8de85704 | 5 | * Copyright (C) 2020 Intel Corporation |
765cb46a JM |
6 | */ |
7 | ||
8 | #include <linux/kernel.h> | |
9 | #include <linux/types.h> | |
10 | #include <linux/crypto.h> | |
4afebd63 | 11 | #include <linux/export.h> |
765cb46a | 12 | #include <linux/err.h> |
0cd20a27 | 13 | #include <crypto/aes.h> |
765cb46a JM |
14 | |
15 | #include <net/mac80211.h> | |
16 | #include "key.h" | |
17 | #include "aes_cmac.h" | |
18 | ||
765cb46a | 19 | #define CMAC_TLEN 8 /* CMAC TLen = 64 bits (8 octets) */ |
56c52da2 | 20 | #define CMAC_TLEN_256 16 /* CMAC TLen = 128 bits (16 octets) */ |
765cb46a JM |
21 | #define AAD_LEN 20 |
22 | ||
26717828 | 23 | static const u8 zero[CMAC_TLEN_256]; |
765cb46a | 24 | |
26717828 | 25 | void ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad, |
765cb46a JM |
26 | const u8 *data, size_t data_len, u8 *mic) |
27 | { | |
26717828 AB |
28 | SHASH_DESC_ON_STACK(desc, tfm); |
29 | u8 out[AES_BLOCK_SIZE]; | |
2d5d4b0a | 30 | const __le16 *fc; |
765cb46a | 31 | |
26717828 | 32 | desc->tfm = tfm; |
765cb46a | 33 | |
26717828 AB |
34 | crypto_shash_init(desc); |
35 | crypto_shash_update(desc, aad, AAD_LEN); | |
2d5d4b0a JM |
36 | fc = (const __le16 *)aad; |
37 | if (ieee80211_is_beacon(*fc)) { | |
38 | /* mask Timestamp field to zero */ | |
39 | crypto_shash_update(desc, zero, 8); | |
40 | crypto_shash_update(desc, data + 8, data_len - 8 - CMAC_TLEN); | |
41 | } else { | |
42 | crypto_shash_update(desc, data, data_len - CMAC_TLEN); | |
43 | } | |
26717828 AB |
44 | crypto_shash_finup(desc, zero, CMAC_TLEN, out); |
45 | ||
46 | memcpy(mic, out, CMAC_TLEN); | |
765cb46a JM |
47 | } |
48 | ||
26717828 | 49 | void ieee80211_aes_cmac_256(struct crypto_shash *tfm, const u8 *aad, |
56c52da2 JM |
50 | const u8 *data, size_t data_len, u8 *mic) |
51 | { | |
26717828 | 52 | SHASH_DESC_ON_STACK(desc, tfm); |
2d5d4b0a | 53 | const __le16 *fc; |
56c52da2 | 54 | |
26717828 | 55 | desc->tfm = tfm; |
56c52da2 | 56 | |
26717828 AB |
57 | crypto_shash_init(desc); |
58 | crypto_shash_update(desc, aad, AAD_LEN); | |
2d5d4b0a JM |
59 | fc = (const __le16 *)aad; |
60 | if (ieee80211_is_beacon(*fc)) { | |
61 | /* mask Timestamp field to zero */ | |
62 | crypto_shash_update(desc, zero, 8); | |
63 | crypto_shash_update(desc, data + 8, | |
64 | data_len - 8 - CMAC_TLEN_256); | |
65 | } else { | |
66 | crypto_shash_update(desc, data, data_len - CMAC_TLEN_256); | |
67 | } | |
26717828 | 68 | crypto_shash_finup(desc, zero, CMAC_TLEN_256, mic); |
56c52da2 | 69 | } |
765cb46a | 70 | |
26717828 AB |
71 | struct crypto_shash *ieee80211_aes_cmac_key_setup(const u8 key[], |
72 | size_t key_len) | |
765cb46a | 73 | { |
26717828 | 74 | struct crypto_shash *tfm; |
765cb46a | 75 | |
26717828 | 76 | tfm = crypto_alloc_shash("cmac(aes)", 0, 0); |
8de85704 JB |
77 | if (!IS_ERR(tfm)) { |
78 | int err = crypto_shash_setkey(tfm, key, key_len); | |
79 | ||
80 | if (err) { | |
81 | crypto_free_shash(tfm); | |
82 | return ERR_PTR(err); | |
83 | } | |
84 | } | |
765cb46a JM |
85 | |
86 | return tfm; | |
87 | } | |
88 | ||
26717828 | 89 | void ieee80211_aes_cmac_key_free(struct crypto_shash *tfm) |
765cb46a | 90 | { |
26717828 | 91 | crypto_free_shash(tfm); |
765cb46a | 92 | } |