1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* |
3 | * Common values for AES algorithms |
4 | */ |
5 | |
6 | #ifndef _CRYPTO_AES_H |
7 | #define _CRYPTO_AES_H |
8 | |
9 | #include <linux/types.h> |
10 | #include <linux/crypto.h> |
11 | |
12 | #define AES_MIN_KEY_SIZE 16 |
13 | #define AES_MAX_KEY_SIZE 32 |
14 | #define AES_KEYSIZE_128 16 |
15 | #define AES_KEYSIZE_192 24 |
16 | #define AES_KEYSIZE_256 32 |
17 | #define AES_BLOCK_SIZE 16 |
18 | #define AES_MAX_KEYLENGTH (15 * 16) |
19 | #define AES_MAX_KEYLENGTH_U32 (AES_MAX_KEYLENGTH / sizeof(u32)) |
20 | |
21 | /* |
22 | * Please ensure that the first two fields are 16-byte aligned |
23 | * relative to the start of the structure, i.e., don't move them! |
24 | */ |
25 | struct crypto_aes_ctx { |
26 | u32 key_enc[AES_MAX_KEYLENGTH_U32]; |
27 | u32 key_dec[AES_MAX_KEYLENGTH_U32]; |
28 | u32 key_length; |
29 | }; |
30 | |
31 | extern const u32 crypto_ft_tab[4][256] ____cacheline_aligned; |
32 | extern const u32 crypto_it_tab[4][256] ____cacheline_aligned; |
33 | |
34 | /* |
35 | * validate key length for AES algorithms |
36 | */ |
37 | static inline int aes_check_keylen(unsigned int keylen) |
38 | { |
39 | switch (keylen) { |
40 | case AES_KEYSIZE_128: |
41 | case AES_KEYSIZE_192: |
42 | case AES_KEYSIZE_256: |
43 | break; |
44 | default: |
45 | return -EINVAL; |
46 | } |
47 | |
48 | return 0; |
49 | } |
50 | |
51 | int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, |
52 | unsigned int key_len); |
53 | |
54 | /** |
55 | * aes_expandkey - Expands the AES key as described in FIPS-197 |
56 | * @ctx: The location where the computed key will be stored. |
57 | * @in_key: The supplied key. |
58 | * @key_len: The length of the supplied key. |
59 | * |
60 | * Returns 0 on success. The function fails only if an invalid key size (or |
61 | * pointer) is supplied. |
62 | * The expanded key size is 240 bytes (max of 14 rounds with a unique 16 bytes |
63 | * key schedule plus a 16 bytes key which is used before the first round). |
64 | * The decryption key is prepared for the "Equivalent Inverse Cipher" as |
65 | * described in FIPS-197. The first slot (16 bytes) of each key (enc or dec) is |
66 | * for the initial combination, the second slot for the first round and so on. |
67 | */ |
68 | int aes_expandkey(struct crypto_aes_ctx *ctx, const u8 *in_key, |
69 | unsigned int key_len); |
70 | |
71 | /** |
72 | * aes_encrypt - Encrypt a single AES block |
73 | * @ctx: Context struct containing the key schedule |
74 | * @out: Buffer to store the ciphertext |
75 | * @in: Buffer containing the plaintext |
76 | */ |
77 | void aes_encrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in); |
78 | |
79 | /** |
80 | * aes_decrypt - Decrypt a single AES block |
81 | * @ctx: Context struct containing the key schedule |
82 | * @out: Buffer to store the plaintext |
83 | * @in: Buffer containing the ciphertext |
84 | */ |
85 | void aes_decrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in); |
86 | |
87 | extern const u8 crypto_aes_sbox[]; |
88 | extern const u8 crypto_aes_inv_sbox[]; |
89 | |
90 | #endif |
91 | |