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Diffstat (limited to 'include/crypto/aes.h')
| -rw-r--r-- | include/crypto/aes.h | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/include/crypto/aes.h b/include/crypto/aes.h new file mode 100644 index 0000000000..2090729701 --- /dev/null +++ b/include/crypto/aes.h @@ -0,0 +1,90 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Common values for AES algorithms + */ + +#ifndef _CRYPTO_AES_H +#define _CRYPTO_AES_H + +#include <linux/types.h> +#include <linux/crypto.h> + +#define AES_MIN_KEY_SIZE 16 +#define AES_MAX_KEY_SIZE 32 +#define AES_KEYSIZE_128 16 +#define AES_KEYSIZE_192 24 +#define AES_KEYSIZE_256 32 +#define AES_BLOCK_SIZE 16 +#define AES_MAX_KEYLENGTH (15 * 16) +#define AES_MAX_KEYLENGTH_U32 (AES_MAX_KEYLENGTH / sizeof(u32)) + +/* + * Please ensure that the first two fields are 16-byte aligned + * relative to the start of the structure, i.e., don't move them! + */ +struct crypto_aes_ctx { + u32 key_enc[AES_MAX_KEYLENGTH_U32]; + u32 key_dec[AES_MAX_KEYLENGTH_U32]; + u32 key_length; +}; + +extern const u32 crypto_ft_tab[4][256] ____cacheline_aligned; +extern const u32 crypto_it_tab[4][256] ____cacheline_aligned; + +/* + * validate key length for AES algorithms + */ +static inline int aes_check_keylen(unsigned int keylen) +{ + switch (keylen) { + case AES_KEYSIZE_128: + case AES_KEYSIZE_192: + case AES_KEYSIZE_256: + break; + default: + return -EINVAL; + } + + return 0; +} + +int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, + unsigned int key_len); + +/** + * aes_expandkey - Expands the AES key as described in FIPS-197 + * @ctx: The location where the computed key will be stored. + * @in_key: The supplied key. + * @key_len: The length of the supplied key. + * + * Returns 0 on success. The function fails only if an invalid key size (or + * pointer) is supplied. + * The expanded key size is 240 bytes (max of 14 rounds with a unique 16 bytes + * key schedule plus a 16 bytes key which is used before the first round). + * The decryption key is prepared for the "Equivalent Inverse Cipher" as + * described in FIPS-197. The first slot (16 bytes) of each key (enc or dec) is + * for the initial combination, the second slot for the first round and so on. + */ +int aes_expandkey(struct crypto_aes_ctx *ctx, const u8 *in_key, + unsigned int key_len); + +/** + * aes_encrypt - Encrypt a single AES block + * @ctx: Context struct containing the key schedule + * @out: Buffer to store the ciphertext + * @in: Buffer containing the plaintext + */ +void aes_encrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in); + +/** + * aes_decrypt - Decrypt a single AES block + * @ctx: Context struct containing the key schedule + * @out: Buffer to store the plaintext + * @in: Buffer containing the ciphertext + */ +void aes_decrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in); + +extern const u8 crypto_aes_sbox[]; +extern const u8 crypto_aes_inv_sbox[]; + +#endif |