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> | |
765cb46a JM |
5 | */ |
6 | ||
7 | #include <linux/kernel.h> | |
8 | #include <linux/types.h> | |
9 | #include <linux/crypto.h> | |
4afebd63 | 10 | #include <linux/export.h> |
765cb46a | 11 | #include <linux/err.h> |
0cd20a27 | 12 | #include <crypto/aes.h> |
765cb46a JM |
13 | |
14 | #include <net/mac80211.h> | |
15 | #include "key.h" | |
16 | #include "aes_cmac.h" | |
17 | ||
765cb46a | 18 | #define CMAC_TLEN 8 /* CMAC TLen = 64 bits (8 octets) */ |
56c52da2 | 19 | #define CMAC_TLEN_256 16 /* CMAC TLen = 128 bits (16 octets) */ |
765cb46a JM |
20 | #define AAD_LEN 20 |
21 | ||
26717828 | 22 | static const u8 zero[CMAC_TLEN_256]; |
765cb46a | 23 | |
26717828 | 24 | void ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad, |
765cb46a JM |
25 | const u8 *data, size_t data_len, u8 *mic) |
26 | { | |
26717828 AB |
27 | SHASH_DESC_ON_STACK(desc, tfm); |
28 | u8 out[AES_BLOCK_SIZE]; | |
2d5d4b0a | 29 | const __le16 *fc; |
765cb46a | 30 | |
26717828 | 31 | desc->tfm = tfm; |
765cb46a | 32 | |
26717828 AB |
33 | crypto_shash_init(desc); |
34 | crypto_shash_update(desc, aad, AAD_LEN); | |
2d5d4b0a JM |
35 | fc = (const __le16 *)aad; |
36 | if (ieee80211_is_beacon(*fc)) { | |
37 | /* mask Timestamp field to zero */ | |
38 | crypto_shash_update(desc, zero, 8); | |
39 | crypto_shash_update(desc, data + 8, data_len - 8 - CMAC_TLEN); | |
40 | } else { | |
41 | crypto_shash_update(desc, data, data_len - CMAC_TLEN); | |
42 | } | |
26717828 AB |
43 | crypto_shash_finup(desc, zero, CMAC_TLEN, out); |
44 | ||
45 | memcpy(mic, out, CMAC_TLEN); | |
765cb46a JM |
46 | } |
47 | ||
26717828 | 48 | void ieee80211_aes_cmac_256(struct crypto_shash *tfm, const u8 *aad, |
56c52da2 JM |
49 | const u8 *data, size_t data_len, u8 *mic) |
50 | { | |
26717828 | 51 | SHASH_DESC_ON_STACK(desc, tfm); |
2d5d4b0a | 52 | const __le16 *fc; |
56c52da2 | 53 | |
26717828 | 54 | desc->tfm = tfm; |
56c52da2 | 55 | |
26717828 AB |
56 | crypto_shash_init(desc); |
57 | crypto_shash_update(desc, aad, AAD_LEN); | |
2d5d4b0a JM |
58 | fc = (const __le16 *)aad; |
59 | if (ieee80211_is_beacon(*fc)) { | |
60 | /* mask Timestamp field to zero */ | |
61 | crypto_shash_update(desc, zero, 8); | |
62 | crypto_shash_update(desc, data + 8, | |
63 | data_len - 8 - CMAC_TLEN_256); | |
64 | } else { | |
65 | crypto_shash_update(desc, data, data_len - CMAC_TLEN_256); | |
66 | } | |
26717828 | 67 | crypto_shash_finup(desc, zero, CMAC_TLEN_256, mic); |
56c52da2 | 68 | } |
765cb46a | 69 | |
26717828 AB |
70 | struct crypto_shash *ieee80211_aes_cmac_key_setup(const u8 key[], |
71 | size_t key_len) | |
765cb46a | 72 | { |
26717828 | 73 | struct crypto_shash *tfm; |
765cb46a | 74 | |
26717828 | 75 | tfm = crypto_alloc_shash("cmac(aes)", 0, 0); |
1ac62ba7 | 76 | if (!IS_ERR(tfm)) |
26717828 | 77 | crypto_shash_setkey(tfm, key, key_len); |
765cb46a JM |
78 | |
79 | return tfm; | |
80 | } | |
81 | ||
26717828 | 82 | void ieee80211_aes_cmac_key_free(struct crypto_shash *tfm) |
765cb46a | 83 | { |
26717828 | 84 | crypto_free_shash(tfm); |
765cb46a | 85 | } |