/*
 psec2.h - PSEC-2 software specification

 Copyright NTT MCL, 2000.

 Duncan S Wong
 Security Group, NTT MCL
 July 2000
*/


typedef unsigned char  BYTE;
typedef unsigned long  WORD;

#define MAX_FIELD_LEN            256

#define TRUE                     1
#define FALSE                    0

#define MAX_IV_SIZE              16          /* # bytes */
#define ENCRYPT_BLOCK_LEN        128
#define MAX_ROUNDS               24

#define MODE_UNSPECIFIED         0
#define MODE_ECB                 1
#define MODE_CBC                 2
#define MODE_CFB                 3

#define ENCRYPT_ALG_XOR          1          /* one-time pad */
#define DIR_ENCRYPT              0
#define DIR_DECRYPT              1

#define MD_MD5                   1
#define MD_SHA                   2


/* PSEC-2 public and private key */
typedef struct {
	EC_POINT pk;
	WORD Hid;
	WORD Gid;
	WORD hLen;
	WORD gLen;
	WORD rLen;
	WORD mLen;
} PSEC2_PUB_KEY;

typedef struct {
	mpz_t sk;
} PSEC2_PRIV_KEY;


/* Symmetric-key cipher information */
typedef struct {
	BYTE algorithmID;
	BYTE mode;
	BYTE direction;           /* encrypting or decrypting */
	BYTE IV[MAX_IV_SIZE];     /* initialization vector */
	WORD S[MAX_ROUNDS];       /* key schedule */
} CIPHER_INFO;


/* PSEC-2 ciphertext */
typedef struct {
	EC_POINT C1;
	mpz_t c2;
	BYTE *c3;
	WORD cipherLen;
} PSEC2_CIPHERTEXT;
	

/* key-pair generation */
BYTE PSEC2_KeyGeneration (
	EC_PARAM     *E,
	mpz_t        sk,
	EC_POINT     *pk
);


/* encryption */
BYTE PSEC2_Encryption (
	BYTE             *message,       /* plaintext */
	CIPHER_INFO      *cipherInfo,
	PSEC2_PUB_KEY    *publicKey,     /* PSEC2 public key */
	PSEC2_CIPHERTEXT *ciphertext,    /* returned ciphertext */
	EC_PARAM         *E
);


/* decryption */
BYTE PSEC2_Decryption (
	PSEC2_CIPHERTEXT *ciphertext,
	CIPHER_INFO      *cipherInfo,
	PSEC2_PUB_KEY    *publicKey,
	PSEC2_PRIV_KEY   *privateKey,
	BYTE             *message,
	EC_PARAM         *E
);


#define ABS(x) (x >= 0 ? x : -x)