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 int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 35 unsigned int key_len); 36 37 /** 38 * aes_expandkey - Expands the AES key as described in FIPS-197 39 * @ctx: The location where the computed key will be stored. 40 * @in_key: The supplied key. 41 * @key_len: The length of the supplied key. 42 * 43 * Returns 0 on success. The function fails only if an invalid key size (or 44 * pointer) is supplied. 45 * The expanded key size is 240 bytes (max of 14 rounds with a unique 16 bytes 46 * key schedule plus a 16 bytes key which is used before the first round). 47 * The decryption key is prepared for the "Equivalent Inverse Cipher" as 48 * described in FIPS-197. The first slot (16 bytes) of each key (enc or dec) is 49 * for the initial combination, the second slot for the first round and so on. 50 */ 51 int aes_expandkey(struct crypto_aes_ctx *ctx, const u8 *in_key, 52 unsigned int key_len); 53 54 /** 55 * aes_encrypt - Encrypt a single AES block 56 * @ctx: Context struct containing the key schedule 57 * @out: Buffer to store the ciphertext 58 * @in: Buffer containing the plaintext 59 */ 60 void aes_encrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in); 61 62 /** 63 * aes_decrypt - Decrypt a single AES block 64 * @ctx: Context struct containing the key schedule 65 * @out: Buffer to store the plaintext 66 * @in: Buffer containing the ciphertext 67 */ 68 void aes_decrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in); 69 70 extern const u8 crypto_aes_sbox[]; 71 extern const u8 crypto_aes_inv_sbox[]; 72 73 #endif 74