#ifndef _crypto_h_
#define _crypto_h_

#include "type.h"
#include "def.h"

/* LFSR */
typedef struct {
	uint32 state;
	uint8 taps[32];
} CRYPTO_LFSR;
void cyrpto_LFSRinit(CRYPTO_LFSR *LFSR, uint32 state, uint8 *taps);
uint32 crypto_LFSRshift(CRYPTO_LFSR *LFSR);

/* PRNG */
uint32 crypto_rand(uint32 seed);

/* [STREAM] RC4 */
typedef struct {
	uint8 S[256];
} CRYPTO_RC4;
void crypto_RC4init(CRYPTO_RC4 *rc4, uint8 *key, uint32 keysz);
uint8 crypto_RC4byte(CRYPTO_RC4 *rc4);
void crypto_RC4inplace(CRYPTO_RC4 *rc4, uint8 *data, uint32 sz);
void crypto_RC4encrypt(uint8 *key, uint32 keysz, uint8 *data, uint32 datasz);

/* [BLOCK] XTEA */
void crypto_XTEAencrypt(uint32 rounds, uint32 data[2], uint32 key[4]);
void crypto_XTEAdecrypt(uint32 rounds, uint32 data[2], uint32 key[4]);

/* [BLOCK] SKIPJACK */
uint16 crypto_SKIPJACK_G(uint16 g, uint8 k, uint8 *key);
uint16 crypto_SKIPJACK_Gi(uint16 g, uint8 k, uint8 *key);
void crypto_SKIPJACKencrypt(uint16 data[4], uint8 key[5]);
void crypto_SKIPJACKdecrypt(uint16 data[4], uint8 key[5]);

/* [KEY XCNG] DIFFIE-HELLMAN */
typedef struct {
	uint32 p, g;
	uint32 a, A;
	uint32 secret;
} crypto_DHKE;
void crypto_DHKEinit(crypto_DHKE *DHKE, uint32 p, uint32 g);
void crypto_DHKEcomputeshared(crypto_DHKE *DHKE, uint32 B);

#endif