mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-12-28 09:08:07 +00:00
46 lines
1.5 KiB
C
46 lines
1.5 KiB
C
/*
|
|
Public domain by Andrew M. <liquidsun@gmail.com>
|
|
*/
|
|
|
|
|
|
/*
|
|
Arithmetic modulo the group order n = 2^252 + 27742317777372353535851937790883648493 = 7237005577332262213973186563042994240857116359379907606001950938285454250989
|
|
|
|
k = 32
|
|
b = 1 << 8 = 256
|
|
m = 2^252 + 27742317777372353535851937790883648493 = 0x1000000000000000000000000000000014def9dea2f79cd65812631a5cf5d3ed
|
|
mu = floor( b^(k*2) / m ) = 0xfffffffffffffffffffffffffffffffeb2106215d086329a7ed9ce5a30a2c131b
|
|
*/
|
|
|
|
#define bignum256modm_bits_per_limb 30
|
|
#define bignum256modm_limb_size 9
|
|
|
|
typedef uint32_t bignum256modm_element_t;
|
|
typedef bignum256modm_element_t bignum256modm[9];
|
|
|
|
/* see HAC, Alg. 14.42 Step 4 */
|
|
void reduce256_modm(bignum256modm r);
|
|
|
|
/*
|
|
Barrett reduction, see HAC, Alg. 14.42
|
|
|
|
Instead of passing in x, pre-process in to q1 and r1 for efficiency
|
|
*/
|
|
void barrett_reduce256_modm(bignum256modm r, const bignum256modm q1, const bignum256modm r1);
|
|
|
|
/* addition modulo m */
|
|
void add256_modm(bignum256modm r, const bignum256modm x, const bignum256modm y);
|
|
|
|
/* multiplication modulo m */
|
|
void mul256_modm(bignum256modm r, const bignum256modm x, const bignum256modm y);
|
|
|
|
void expand256_modm(bignum256modm out, const unsigned char *in, size_t len);
|
|
|
|
void expand_raw256_modm(bignum256modm out, const unsigned char in[32]);
|
|
|
|
void contract256_modm(unsigned char out[32], const bignum256modm in);
|
|
|
|
void contract256_window4_modm(signed char r[64], const bignum256modm in);
|
|
|
|
void contract256_slidingwindow_modm(signed char r[256], const bignum256modm s, int windowsize);
|