mirror of
https://github.com/DrKLO/Telegram.git
synced 2024-12-22 22:45:18 +01:00
145 lines
5.7 KiB
C
145 lines
5.7 KiB
C
/********************************************************************************************
|
|
* SIDH: an efficient supersingular isogeny cryptography library
|
|
*
|
|
* Abstract: internal header file for P434
|
|
*********************************************************************************************/
|
|
|
|
#ifndef UTILS_H_
|
|
#define UTILS_H_
|
|
|
|
#include <openssl/base.h>
|
|
|
|
#include "../crypto/internal.h"
|
|
#include "sike.h"
|
|
|
|
// Conversion macro from number of bits to number of bytes
|
|
#define BITS_TO_BYTES(nbits) (((nbits)+7)/8)
|
|
|
|
// Bit size of the field
|
|
#define BITS_FIELD 434
|
|
// Byte size of the field
|
|
#define FIELD_BYTESZ BITS_TO_BYTES(BITS_FIELD)
|
|
// Number of 64-bit words of a 224-bit element
|
|
#define NBITS_ORDER 224
|
|
#define NWORDS64_ORDER ((NBITS_ORDER+63)/64)
|
|
// Number of elements in Alice's strategy
|
|
#define A_max 108
|
|
// Number of elements in Bob's strategy
|
|
#define B_max 137
|
|
// Word size size
|
|
#define RADIX sizeof(crypto_word_t)*8
|
|
// Byte size of a limb
|
|
#define LSZ sizeof(crypto_word_t)
|
|
|
|
#if defined(OPENSSL_64_BIT)
|
|
// Number of words of a 434-bit field element
|
|
#define NWORDS_FIELD 7
|
|
// Number of "0" digits in the least significant part of p434 + 1
|
|
#define ZERO_WORDS 3
|
|
// U64_TO_WORDS expands |x| for a |crypto_word_t| array literal.
|
|
#define U64_TO_WORDS(x) UINT64_C(x)
|
|
#else
|
|
// Number of words of a 434-bit field element
|
|
#define NWORDS_FIELD 14
|
|
// Number of "0" digits in the least significant part of p434 + 1
|
|
#define ZERO_WORDS 6
|
|
// U64_TO_WORDS expands |x| for a |crypto_word_t| array literal.
|
|
#define U64_TO_WORDS(x) \
|
|
(uint32_t)(UINT64_C(x) & 0xffffffff), (uint32_t)(UINT64_C(x) >> 32)
|
|
#endif
|
|
|
|
// Extended datatype support
|
|
#if !defined(BORINGSSL_HAS_UINT128)
|
|
typedef uint64_t uint128_t[2];
|
|
#endif
|
|
|
|
// The following functions return 1 (TRUE) if condition is true, 0 (FALSE) otherwise
|
|
// Digit multiplication
|
|
#define MUL(multiplier, multiplicand, hi, lo) digit_x_digit((multiplier), (multiplicand), &(lo));
|
|
|
|
// If mask |x|==0xff.ff set |x| to 1, otherwise 0
|
|
#define M2B(x) ((x)>>(RADIX-1))
|
|
|
|
// Digit addition with carry
|
|
#define ADDC(carryIn, addend1, addend2, carryOut, sumOut) \
|
|
do { \
|
|
crypto_word_t tempReg = (addend1) + (crypto_word_t)(carryIn); \
|
|
(sumOut) = (addend2) + tempReg; \
|
|
(carryOut) = M2B(constant_time_lt_w(tempReg, (crypto_word_t)(carryIn)) | \
|
|
constant_time_lt_w((sumOut), tempReg)); \
|
|
} while(0)
|
|
|
|
// Digit subtraction with borrow
|
|
#define SUBC(borrowIn, minuend, subtrahend, borrowOut, differenceOut) \
|
|
do { \
|
|
crypto_word_t tempReg = (minuend) - (subtrahend); \
|
|
crypto_word_t borrowReg = M2B(constant_time_lt_w((minuend), (subtrahend))); \
|
|
borrowReg |= ((borrowIn) & constant_time_is_zero_w(tempReg)); \
|
|
(differenceOut) = tempReg - (crypto_word_t)(borrowIn); \
|
|
(borrowOut) = borrowReg; \
|
|
} while(0)
|
|
|
|
/* Old GCC 4.9 (jessie) doesn't implement {0} initialization properly,
|
|
which violates C11 as described in 6.7.9, 21 (similarily C99, 6.7.8).
|
|
Defines below are used to work around the bug, and provide a way
|
|
to initialize f2elem_t and point_proj_t structs.
|
|
Bug has been fixed in GCC6 (debian stretch).
|
|
*/
|
|
#define F2ELM_INIT {{ {0}, {0} }}
|
|
#define POINT_PROJ_INIT {{ F2ELM_INIT, F2ELM_INIT }}
|
|
|
|
// Datatype for representing 434-bit field elements (448-bit max.)
|
|
// Elements over GF(p434) are encoded in 63 octets in little endian format
|
|
// (i.e., the least significant octet is located in the lowest memory address).
|
|
typedef crypto_word_t felm_t[NWORDS_FIELD];
|
|
|
|
// An element in F_{p^2}, is composed of two coefficients from F_p, * i.e.
|
|
// Fp2 element = c0 + c1*i in F_{p^2}
|
|
// Datatype for representing double-precision 2x434-bit field elements (448-bit max.)
|
|
// Elements (a+b*i) over GF(p434^2), where a and b are defined over GF(p434), are
|
|
// encoded as {a, b}, with a in the lowest memory portion.
|
|
typedef struct {
|
|
felm_t c0;
|
|
felm_t c1;
|
|
} fp2;
|
|
|
|
// Our F_{p^2} element type is a pointer to the struct.
|
|
typedef fp2 f2elm_t[1];
|
|
|
|
// Datatype for representing double-precision 2x434-bit
|
|
// field elements in contiguous memory.
|
|
typedef crypto_word_t dfelm_t[2*NWORDS_FIELD];
|
|
|
|
// Constants used during SIKE computation.
|
|
struct params_t {
|
|
// Stores a prime
|
|
const crypto_word_t prime[NWORDS_FIELD];
|
|
// Stores prime + 1
|
|
const crypto_word_t prime_p1[NWORDS_FIELD];
|
|
// Stores prime * 2
|
|
const crypto_word_t prime_x2[NWORDS_FIELD];
|
|
// Alice's generator values {XPA0 + XPA1*i, XQA0 + XQA1*i, XRA0 + XRA1*i}
|
|
// in GF(prime^2), expressed in Montgomery representation
|
|
const crypto_word_t A_gen[6*NWORDS_FIELD];
|
|
// Bob's generator values {XPB0 + XPB1*i, XQB0 + XQB1*i, XRB0 + XRB1*i}
|
|
// in GF(prime^2), expressed in Montgomery representation
|
|
const crypto_word_t B_gen[6*NWORDS_FIELD];
|
|
// Montgomery constant mont_R2 = (2^448)^2 mod prime
|
|
const crypto_word_t mont_R2[NWORDS_FIELD];
|
|
// Value 'one' in Montgomery representation
|
|
const crypto_word_t mont_one[NWORDS_FIELD];
|
|
// Value '6' in Montgomery representation
|
|
const crypto_word_t mont_six[NWORDS_FIELD];
|
|
// Fixed parameters for isogeny tree computation
|
|
const unsigned int A_strat[A_max-1];
|
|
const unsigned int B_strat[B_max-1];
|
|
};
|
|
|
|
// Point representation in projective XZ Montgomery coordinates.
|
|
typedef struct {
|
|
f2elm_t X;
|
|
f2elm_t Z;
|
|
} point_proj;
|
|
typedef point_proj point_proj_t[1];
|
|
|
|
#endif // UTILS_H_
|