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Commit 5427663f authored by Sebastian Siewior's avatar Sebastian Siewior Committed by Herbert Xu
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[CRYPTO] aes: Export generic setkey 



The key expansion routine could be get little more generic, become
a kernel doc entry and then get exported.

Signed-off-by: default avatarSebastian Siewior <sebastian@breakpoint.cc>
Tested-by: default avatarStefan Hellermann <stefan@the2masters.de>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent c3715cb9

crypto/aes_generic.c

+47 −9
Original line number Diff line number Diff line
@@ -229,18 +229,29 @@ static void __init gen_tabs(void) 
	ctx->key_enc[8 * i + 15] = t;			\

} while (0)



int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,

/**

 * crypto_aes_expand_key - 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 crypto_aes_expand_key(struct crypto_aes_ctx *ctx, const u8 *in_key,

		unsigned int key_len)

{

	struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);

	const __le32 *key = (const __le32 *)in_key;

	u32 *flags = &tfm->crt_flags;

	u32 i, t, u, v, w, j;



	if (key_len % 8) {

		*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;

	if (key_len != AES_KEYSIZE_128 && key_len != AES_KEYSIZE_192 &&

			key_len != AES_KEYSIZE_256)

		return -EINVAL;

	}



	ctx->key_length = key_len;
@@ -250,20 +261,20 @@ int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 
	ctx->key_dec[key_len + 27] = ctx->key_enc[3] = le32_to_cpu(key[3]);



	switch (key_len) {

	case 16:

	case AES_KEYSIZE_128:

		t = ctx->key_enc[3];

		for (i = 0; i < 10; ++i)

			loop4(i);

		break;



	case 24:

	case AES_KEYSIZE_192:

		ctx->key_enc[4] = le32_to_cpu(key[4]);

		t = ctx->key_enc[5] = le32_to_cpu(key[5]);

		for (i = 0; i < 8; ++i)

			loop6(i);

		break;



	case 32:

	case AES_KEYSIZE_256:

		ctx->key_enc[4] = le32_to_cpu(key[4]);

		ctx->key_enc[5] = le32_to_cpu(key[5]);

		ctx->key_enc[6] = le32_to_cpu(key[6]);
@@ -284,6 +295,33 @@ int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 
	}

	return 0;

}

EXPORT_SYMBOL_GPL(crypto_aes_expand_key);



/**

 * crypto_aes_set_key - Set the AES key.

 * @tfm:	The %crypto_tfm that is used in the context.

 * @in_key:	The input key.

 * @key_len:	The size of the key.

 *

 * Returns 0 on success, on failure the %CRYPTO_TFM_RES_BAD_KEY_LEN flag in tfm

 * is set. The function uses crypto_aes_expand_key() to expand the key.

 * &crypto_aes_ctx _must_ be the private data embedded in @tfm which is

 * retrieved with crypto_tfm_ctx().

 */

int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,

		unsigned int key_len)

{

	struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);

	u32 *flags = &tfm->crt_flags;

	int ret;



	ret = crypto_aes_expand_key(ctx, in_key, key_len);

	if (!ret)

		return 0;



	*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;

	return -EINVAL;

}

EXPORT_SYMBOL_GPL(crypto_aes_set_key);



/* encrypt a block of text */

include/crypto/aes.h

+6 −2
Original line number Diff line number Diff line
@@ -14,11 +14,13 @@ 
#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))



struct crypto_aes_ctx {

	u32 key_length;

	u32 key_enc[60];

	u32 key_dec[60];

	u32 key_enc[AES_MAX_KEYLENGTH_U32];

	u32 key_dec[AES_MAX_KEYLENGTH_U32];

};



extern u32 crypto_ft_tab[4][256];
@@ -28,4 +30,6 @@ extern u32 crypto_il_tab[4][256]; 


int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,

		unsigned int key_len);

int crypto_aes_expand_key(struct crypto_aes_ctx *ctx, const u8 *in_key,

		unsigned int key_len);

#endif