Mercurial > dropbear
diff libtommath/bn_mp_montgomery_setup.c @ 1655:f52919ffd3b1
update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
* make key-generation compliant to FIPS 186.4
* fix includes in tommath_class.h
* update fuzzcorpus instead of error-out
* fixup fuzzing make-targets
* update Makefile.in
* apply necessary patches to ltm sources
* clean-up not required ltm files
* update to vanilla ltm 1.1.0
this already only contains the required files
* remove set/get double
| author | Steffen Jaeckel <s_jaeckel@gmx.de> |
|---|---|
| date | Mon, 16 Sep 2019 15:50:38 +0200 |
| parents | 8bba51a55704 |
| children | 1051e4eea25a |
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--- a/libtommath/bn_mp_montgomery_setup.c Wed May 15 21:59:45 2019 +0800 +++ b/libtommath/bn_mp_montgomery_setup.c Mon Sep 16 15:50:38 2019 +0200 @@ -1,4 +1,4 @@ -#include <tommath_private.h> +#include "tommath_private.h" #ifdef BN_MP_MONTGOMERY_SETUP_C /* LibTomMath, multiple-precision integer library -- Tom St Denis * @@ -9,51 +9,47 @@ * Michael Fromberger but has been written from scratch with * additional optimizations in place. * - * The library is free for all purposes without any express - * guarantee it works. - * - * Tom St Denis, [email protected], http://libtom.org + * SPDX-License-Identifier: Unlicense */ /* setups the montgomery reduction stuff */ -int -mp_montgomery_setup (mp_int * n, mp_digit * rho) +int mp_montgomery_setup(const mp_int *n, mp_digit *rho) { - mp_digit x, b; + mp_digit x, b; -/* fast inversion mod 2**k - * - * Based on the fact that - * - * XA = 1 (mod 2**n) => (X(2-XA)) A = 1 (mod 2**2n) - * => 2*X*A - X*X*A*A = 1 - * => 2*(1) - (1) = 1 - */ - b = n->dp[0]; + /* fast inversion mod 2**k + * + * Based on the fact that + * + * XA = 1 (mod 2**n) => (X(2-XA)) A = 1 (mod 2**2n) + * => 2*X*A - X*X*A*A = 1 + * => 2*(1) - (1) = 1 + */ + b = n->dp[0]; - if ((b & 1) == 0) { - return MP_VAL; - } + if ((b & 1u) == 0u) { + return MP_VAL; + } - x = (((b + 2) & 4) << 1) + b; /* here x*a==1 mod 2**4 */ - x *= 2 - (b * x); /* here x*a==1 mod 2**8 */ + x = (((b + 2u) & 4u) << 1) + b; /* here x*a==1 mod 2**4 */ + x *= 2u - (b * x); /* here x*a==1 mod 2**8 */ #if !defined(MP_8BIT) - x *= 2 - (b * x); /* here x*a==1 mod 2**16 */ + x *= 2u - (b * x); /* here x*a==1 mod 2**16 */ #endif #if defined(MP_64BIT) || !(defined(MP_8BIT) || defined(MP_16BIT)) - x *= 2 - (b * x); /* here x*a==1 mod 2**32 */ + x *= 2u - (b * x); /* here x*a==1 mod 2**32 */ #endif #ifdef MP_64BIT - x *= 2 - (b * x); /* here x*a==1 mod 2**64 */ + x *= 2u - (b * x); /* here x*a==1 mod 2**64 */ #endif - /* rho = -1/m mod b */ - *rho = (mp_digit)(((mp_word)1 << ((mp_word) DIGIT_BIT)) - x) & MP_MASK; + /* rho = -1/m mod b */ + *rho = (mp_digit)(((mp_word)1 << (mp_word)DIGIT_BIT) - x) & MP_MASK; - return MP_OKAY; + return MP_OKAY; } #endif -/* ref: $Format:%D$ */ -/* git commit: $Format:%H$ */ -/* commit time: $Format:%ai$ */ +/* ref: HEAD -> master, tag: v1.1.0 */ +/* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */ +/* commit time: 2019-01-28 20:32:32 +0100 */