mirror of
https://github.com/torvalds/linux.git
synced 2024-09-20 06:53:04 +00:00
f135440447
Implement AES in CFB mode using the existing, mostly constant-time generic AES library implementation. This will be used by the TPM code to encrypt communications with TPM hardware, which is often a discrete component connected using sniffable wires or traces. While a CFB template does exist, using a skcipher is a major pain for non-performance critical synchronous crypto where the algorithm is known at compile time and the data is in contiguous buffers with valid kernel virtual addresses. Tested-by: James Bottomley <James.Bottomley@HansenPartnership.com> Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Link: https://lore.kernel.org/all/20230216201410.15010-1-James.Bottomley@HansenPartnership.com/ Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Tested-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
96 lines
2.7 KiB
C
96 lines
2.7 KiB
C
/* 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[];
|
|
|
|
void aescfb_encrypt(const struct crypto_aes_ctx *ctx, u8 *dst, const u8 *src,
|
|
int len, const u8 iv[AES_BLOCK_SIZE]);
|
|
void aescfb_decrypt(const struct crypto_aes_ctx *ctx, u8 *dst, const u8 *src,
|
|
int len, const u8 iv[AES_BLOCK_SIZE]);
|
|
|
|
#endif
|