1. 根目录:
2. include
3. crypto
4. twofish.h

#ifndef _CRYPTO_TWOFISH_H
#define _CRYPTO_TWOFISH_H

#include <linux/types.h>

#define TF_MIN_KEY_SIZE 16
#define TF_MAX_KEY_SIZE 32
#define TF_BLOCK_SIZE 16

struct crypto_tfm;

/* Structure for an expanded Twofish key.  s contains the key-dependent
 * S-boxes composed with the MDS matrix; w contains the eight "whitening"
 * subkeys, K[0] through K[7].	k holds the remaining, "round" subkeys.  Note
 * that k[i] corresponds to what the Twofish paper calls K[i+8]. */
struct twofish_ctx {
	u32 s[4][256], w[8], k[32];
};

int __twofish_setkey(struct twofish_ctx *ctx, const u8 *key,
		     unsigned int key_len, u32 *flags);
int twofish_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int key_len);

#endif