279 строки
8.4 KiB
C
279 строки
8.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
/* mpi.h - Multi Precision Integers
|
|
* Copyright (C) 1994, 1996, 1998, 1999,
|
|
* 2000, 2001 Free Software Foundation, Inc.
|
|
*
|
|
* This file is part of GNUPG.
|
|
*
|
|
* Note: This code is heavily based on the GNU MP Library.
|
|
* Actually it's the same code with only minor changes in the
|
|
* way the data is stored; this is to support the abstraction
|
|
* of an optional secure memory allocation which may be used
|
|
* to avoid revealing of sensitive data due to paging etc.
|
|
* The GNU MP Library itself is published under the LGPL;
|
|
* however I decided to publish this code under the plain GPL.
|
|
*/
|
|
|
|
#ifndef G10_MPI_H
|
|
#define G10_MPI_H
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/scatterlist.h>
|
|
|
|
#define BYTES_PER_MPI_LIMB (BITS_PER_LONG / 8)
|
|
#define BITS_PER_MPI_LIMB BITS_PER_LONG
|
|
|
|
typedef unsigned long int mpi_limb_t;
|
|
typedef signed long int mpi_limb_signed_t;
|
|
|
|
struct gcry_mpi {
|
|
int alloced; /* array size (# of allocated limbs) */
|
|
int nlimbs; /* number of valid limbs */
|
|
int nbits; /* the real number of valid bits (info only) */
|
|
int sign; /* indicates a negative number */
|
|
unsigned flags; /* bit 0: array must be allocated in secure memory space */
|
|
/* bit 1: not used */
|
|
/* bit 2: the limb is a pointer to some m_alloced data */
|
|
mpi_limb_t *d; /* array with the limbs */
|
|
};
|
|
|
|
typedef struct gcry_mpi *MPI;
|
|
|
|
#define mpi_get_nlimbs(a) ((a)->nlimbs)
|
|
#define mpi_has_sign(a) ((a)->sign)
|
|
|
|
/*-- mpiutil.c --*/
|
|
MPI mpi_alloc(unsigned nlimbs);
|
|
void mpi_clear(MPI a);
|
|
void mpi_free(MPI a);
|
|
int mpi_resize(MPI a, unsigned nlimbs);
|
|
|
|
static inline MPI mpi_new(unsigned int nbits)
|
|
{
|
|
return mpi_alloc((nbits + BITS_PER_MPI_LIMB - 1) / BITS_PER_MPI_LIMB);
|
|
}
|
|
|
|
MPI mpi_copy(MPI a);
|
|
MPI mpi_alloc_like(MPI a);
|
|
void mpi_snatch(MPI w, MPI u);
|
|
MPI mpi_set(MPI w, MPI u);
|
|
MPI mpi_set_ui(MPI w, unsigned long u);
|
|
MPI mpi_alloc_set_ui(unsigned long u);
|
|
void mpi_swap_cond(MPI a, MPI b, unsigned long swap);
|
|
|
|
/* Constants used to return constant MPIs. See mpi_init if you
|
|
* want to add more constants.
|
|
*/
|
|
#define MPI_NUMBER_OF_CONSTANTS 6
|
|
enum gcry_mpi_constants {
|
|
MPI_C_ZERO,
|
|
MPI_C_ONE,
|
|
MPI_C_TWO,
|
|
MPI_C_THREE,
|
|
MPI_C_FOUR,
|
|
MPI_C_EIGHT
|
|
};
|
|
|
|
MPI mpi_const(enum gcry_mpi_constants no);
|
|
|
|
/*-- mpicoder.c --*/
|
|
|
|
/* Different formats of external big integer representation. */
|
|
enum gcry_mpi_format {
|
|
GCRYMPI_FMT_NONE = 0,
|
|
GCRYMPI_FMT_STD = 1, /* Twos complement stored without length. */
|
|
GCRYMPI_FMT_PGP = 2, /* As used by OpenPGP (unsigned only). */
|
|
GCRYMPI_FMT_SSH = 3, /* As used by SSH (like STD but with length). */
|
|
GCRYMPI_FMT_HEX = 4, /* Hex format. */
|
|
GCRYMPI_FMT_USG = 5, /* Like STD but unsigned. */
|
|
GCRYMPI_FMT_OPAQUE = 8 /* Opaque format (some functions only). */
|
|
};
|
|
|
|
MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes);
|
|
MPI mpi_read_from_buffer(const void *buffer, unsigned *ret_nread);
|
|
int mpi_fromstr(MPI val, const char *str);
|
|
MPI mpi_scanval(const char *string);
|
|
MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len);
|
|
void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign);
|
|
int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes,
|
|
int *sign);
|
|
int mpi_write_to_sgl(MPI a, struct scatterlist *sg, unsigned nbytes,
|
|
int *sign);
|
|
int mpi_print(enum gcry_mpi_format format, unsigned char *buffer,
|
|
size_t buflen, size_t *nwritten, MPI a);
|
|
|
|
/*-- mpi-mod.c --*/
|
|
void mpi_mod(MPI rem, MPI dividend, MPI divisor);
|
|
|
|
/* Context used with Barrett reduction. */
|
|
struct barrett_ctx_s;
|
|
typedef struct barrett_ctx_s *mpi_barrett_t;
|
|
|
|
mpi_barrett_t mpi_barrett_init(MPI m, int copy);
|
|
void mpi_barrett_free(mpi_barrett_t ctx);
|
|
void mpi_mod_barrett(MPI r, MPI x, mpi_barrett_t ctx);
|
|
void mpi_mul_barrett(MPI w, MPI u, MPI v, mpi_barrett_t ctx);
|
|
|
|
/*-- mpi-pow.c --*/
|
|
int mpi_powm(MPI res, MPI base, MPI exp, MPI mod);
|
|
|
|
/*-- mpi-cmp.c --*/
|
|
int mpi_cmp_ui(MPI u, ulong v);
|
|
int mpi_cmp(MPI u, MPI v);
|
|
int mpi_cmpabs(MPI u, MPI v);
|
|
|
|
/*-- mpi-sub-ui.c --*/
|
|
int mpi_sub_ui(MPI w, MPI u, unsigned long vval);
|
|
|
|
/*-- mpi-bit.c --*/
|
|
void mpi_normalize(MPI a);
|
|
unsigned mpi_get_nbits(MPI a);
|
|
int mpi_test_bit(MPI a, unsigned int n);
|
|
void mpi_set_bit(MPI a, unsigned int n);
|
|
void mpi_set_highbit(MPI a, unsigned int n);
|
|
void mpi_clear_highbit(MPI a, unsigned int n);
|
|
void mpi_clear_bit(MPI a, unsigned int n);
|
|
void mpi_rshift_limbs(MPI a, unsigned int count);
|
|
void mpi_rshift(MPI x, MPI a, unsigned int n);
|
|
void mpi_lshift_limbs(MPI a, unsigned int count);
|
|
void mpi_lshift(MPI x, MPI a, unsigned int n);
|
|
|
|
/*-- mpi-add.c --*/
|
|
void mpi_add_ui(MPI w, MPI u, unsigned long v);
|
|
void mpi_add(MPI w, MPI u, MPI v);
|
|
void mpi_sub(MPI w, MPI u, MPI v);
|
|
void mpi_addm(MPI w, MPI u, MPI v, MPI m);
|
|
void mpi_subm(MPI w, MPI u, MPI v, MPI m);
|
|
|
|
/*-- mpi-mul.c --*/
|
|
void mpi_mul(MPI w, MPI u, MPI v);
|
|
void mpi_mulm(MPI w, MPI u, MPI v, MPI m);
|
|
|
|
/*-- mpi-div.c --*/
|
|
void mpi_tdiv_r(MPI rem, MPI num, MPI den);
|
|
void mpi_fdiv_r(MPI rem, MPI dividend, MPI divisor);
|
|
void mpi_fdiv_q(MPI quot, MPI dividend, MPI divisor);
|
|
|
|
/*-- mpi-inv.c --*/
|
|
int mpi_invm(MPI x, MPI a, MPI n);
|
|
|
|
/*-- ec.c --*/
|
|
|
|
/* Object to represent a point in projective coordinates */
|
|
struct gcry_mpi_point {
|
|
MPI x;
|
|
MPI y;
|
|
MPI z;
|
|
};
|
|
|
|
typedef struct gcry_mpi_point *MPI_POINT;
|
|
|
|
/* Models describing an elliptic curve */
|
|
enum gcry_mpi_ec_models {
|
|
/* The Short Weierstrass equation is
|
|
* y^2 = x^3 + ax + b
|
|
*/
|
|
MPI_EC_WEIERSTRASS = 0,
|
|
/* The Montgomery equation is
|
|
* by^2 = x^3 + ax^2 + x
|
|
*/
|
|
MPI_EC_MONTGOMERY,
|
|
/* The Twisted Edwards equation is
|
|
* ax^2 + y^2 = 1 + bx^2y^2
|
|
* Note that we use 'b' instead of the commonly used 'd'.
|
|
*/
|
|
MPI_EC_EDWARDS
|
|
};
|
|
|
|
/* Dialects used with elliptic curves */
|
|
enum ecc_dialects {
|
|
ECC_DIALECT_STANDARD = 0,
|
|
ECC_DIALECT_ED25519,
|
|
ECC_DIALECT_SAFECURVE
|
|
};
|
|
|
|
/* This context is used with all our EC functions. */
|
|
struct mpi_ec_ctx {
|
|
enum gcry_mpi_ec_models model; /* The model describing this curve. */
|
|
enum ecc_dialects dialect; /* The ECC dialect used with the curve. */
|
|
int flags; /* Public key flags (not always used). */
|
|
unsigned int nbits; /* Number of bits. */
|
|
|
|
/* Domain parameters. Note that they may not all be set and if set
|
|
* the MPIs may be flagged as constant.
|
|
*/
|
|
MPI p; /* Prime specifying the field GF(p). */
|
|
MPI a; /* First coefficient of the Weierstrass equation. */
|
|
MPI b; /* Second coefficient of the Weierstrass equation. */
|
|
MPI_POINT G; /* Base point (generator). */
|
|
MPI n; /* Order of G. */
|
|
unsigned int h; /* Cofactor. */
|
|
|
|
/* The actual key. May not be set. */
|
|
MPI_POINT Q; /* Public key. */
|
|
MPI d; /* Private key. */
|
|
|
|
const char *name; /* Name of the curve. */
|
|
|
|
/* This structure is private to mpi/ec.c! */
|
|
struct {
|
|
struct {
|
|
unsigned int a_is_pminus3:1;
|
|
unsigned int two_inv_p:1;
|
|
} valid; /* Flags to help setting the helper vars below. */
|
|
|
|
int a_is_pminus3; /* True if A = P - 3. */
|
|
|
|
MPI two_inv_p;
|
|
|
|
mpi_barrett_t p_barrett;
|
|
|
|
/* Scratch variables. */
|
|
MPI scratch[11];
|
|
|
|
/* Helper for fast reduction. */
|
|
/* int nist_nbits; /\* If this is a NIST curve, the # of bits. *\/ */
|
|
/* MPI s[10]; */
|
|
/* MPI c; */
|
|
} t;
|
|
|
|
/* Curve specific computation routines for the field. */
|
|
void (*addm)(MPI w, MPI u, MPI v, struct mpi_ec_ctx *ctx);
|
|
void (*subm)(MPI w, MPI u, MPI v, struct mpi_ec_ctx *ec);
|
|
void (*mulm)(MPI w, MPI u, MPI v, struct mpi_ec_ctx *ctx);
|
|
void (*pow2)(MPI w, const MPI b, struct mpi_ec_ctx *ctx);
|
|
void (*mul2)(MPI w, MPI u, struct mpi_ec_ctx *ctx);
|
|
};
|
|
|
|
void mpi_ec_init(struct mpi_ec_ctx *ctx, enum gcry_mpi_ec_models model,
|
|
enum ecc_dialects dialect,
|
|
int flags, MPI p, MPI a, MPI b);
|
|
void mpi_ec_deinit(struct mpi_ec_ctx *ctx);
|
|
MPI_POINT mpi_point_new(unsigned int nbits);
|
|
void mpi_point_release(MPI_POINT p);
|
|
void mpi_point_init(MPI_POINT p);
|
|
void mpi_point_free_parts(MPI_POINT p);
|
|
int mpi_ec_get_affine(MPI x, MPI y, MPI_POINT point, struct mpi_ec_ctx *ctx);
|
|
void mpi_ec_add_points(MPI_POINT result,
|
|
MPI_POINT p1, MPI_POINT p2,
|
|
struct mpi_ec_ctx *ctx);
|
|
void mpi_ec_mul_point(MPI_POINT result,
|
|
MPI scalar, MPI_POINT point,
|
|
struct mpi_ec_ctx *ctx);
|
|
int mpi_ec_curve_point(MPI_POINT point, struct mpi_ec_ctx *ctx);
|
|
|
|
/* inline functions */
|
|
|
|
/**
|
|
* mpi_get_size() - returns max size required to store the number
|
|
*
|
|
* @a: A multi precision integer for which we want to allocate a buffer
|
|
*
|
|
* Return: size required to store the number
|
|
*/
|
|
static inline unsigned int mpi_get_size(MPI a)
|
|
{
|
|
return a->nlimbs * BYTES_PER_MPI_LIMB;
|
|
}
|
|
#endif /*G10_MPI_H */
|