X-Git-Url: https://git.distorted.org.uk/~mdw/secnet/blobdiff_plain/137d3b36ce3d121855364d3a28383ab86fbb9d7b..ae8cd973b817f81c075ab20e84d3239125146f24:/f25519.h diff --git a/f25519.h b/f25519.h deleted file mode 100644 index 8450748..0000000 --- a/f25519.h +++ /dev/null @@ -1,329 +0,0 @@ -/* - * f25519.h: arithmetic modulo 2^255 - 19 - */ -/* - * This file is Free Software. It has been modified to as part of its - * incorporation into secnet. - * - * Copyright 2017 Mark Wooding - * - * You may redistribute this file and/or modify it under the terms of - * the permissive licence shown below. - * - * You may redistribute secnet as a whole and/or modify it under the - * terms of the GNU General Public License as published by the Free - * Software Foundation; either version 3, or (at your option) any - * later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, see - * https://www.gnu.org/licenses/gpl.html. - */ -/* - * Imported from Catacomb, and lightly modified for Secnet (2017-04-30): - * - * * Use `fake-mLib-bits.h' in place of the real . - * - * * Remove the 16/32-bit implementation, since C99 always has 64-bit - * arithmetic. - * - * * Disable some of the operations which aren't needed for X25519. - * (They're used for Ed25519, which we don't need.) - * - * The file's original comment headers are preserved below. - */ -/* -*-c-*- - * - * Arithmetic modulo 2^255 - 19 - * - * (c) 2017 Straylight/Edgeware - */ - -/*----- Licensing notice --------------------------------------------------* - * - * This file is part of Catacomb. - * - * Catacomb is free software; you can redistribute it and/or modify - * it under the terms of the GNU Library General Public License as - * published by the Free Software Foundation; either version 2 of the - * License, or (at your option) any later version. - * - * Catacomb is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU Library General Public License for more details. - * - * You should have received a copy of the GNU Library General Public - * License along with Catacomb; if not, write to the Free - * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, - * MA 02111-1307, USA. - */ - -#ifndef CATACOMB_F25519_H -#define CATACOMB_F25519_H - -#ifdef __cplusplus - extern "C" { -#endif - -/*----- Header files ------------------------------------------------------*/ - -#include "fake-mLib-bits.h" - -#ifndef CATACOMB_QFARITH_H -# include "qfarith.h" -#endif - -/*----- Data structures ---------------------------------------------------*/ - -typedef union { - int32 p26[10]; -} f25519; - -/*----- Functions provided ------------------------------------------------*/ - -#define F25519_TRIM_X25519 - -/* --- @f25519_set@ --- * - * - * Arguments: @f25519 *z@ = where to write the result - * @int a@ = a small-ish constant - * - * Returns: --- - * - * Use: Sets @z@ to equal @a@. - */ - -extern void f25519_set(f25519 */*x*/, int /*a*/); - -/* --- @f25519_load@ --- * - * - * Arguments: @f25519 *z@ = where to store the result - * @const octet xv[32]@ = source to read - * - * Returns: --- - * - * Use: Reads an element of %$\gf{2^{255} - 19}$% in external - * representation from @xv@ and stores it in @z@. - * - * External representation is little-endian base-256. Elements - * have multiple encodings, which are not produced by correct - * software; use of noncanonical encodings is not an error, and - * toleration of them is considered a performance feature. - * - * Some specifications, e.g., RFC7748, require the topmost bit - * (i.e., bit 7 of @wv[31]@) to be ignored. Callers - * implementing such specifications should clear the bit - * explicitly. (It's much easier for a caller who wants the bit - * to be ignored to clear it than for a caller who wants the bit - * to be significant to apply the necessary change by hand.) - */ - -extern void f25519_load(f25519 */*z*/, const octet /*xv*/[32]); - -/* --- @f25519_store@ --- * - * - * Arguments: @octet zv[32]@ = where to write the result - * @const f25519 *x@ = the field element to write - * - * Returns: --- - * - * Use: Stores a field element in the given octet vector in external - * representation. A canonical encoding is always stored, so, - * in particular, the top bit of @xv[31]@ is always left clear. - */ - -extern void f25519_store(octet /*zv*/[32], const f25519 */*x*/); - -#ifndef F25519_TRIM_X25519 - -/* --- @f25519_pick2@ --- * - * - * Arguments: @f25519 *z@ = where to put the result (may alias @x@ or @y@) - * @const f25519 *x, *y@ = two operands - * @uint32 m@ = a mask - * - * Returns: --- - * - * Use: If @m@ is zero, set @z = y@; if @m@ is all-bits-set, then set - * @z = x@. If @m@ has some other value, then scramble @z@ in - * an unhelpful way. - */ - -extern void f25519_pick2(f25519 */*z*/, const f25519 */*x*/, - const f25519 */*y*/, uint32 /*m*/); - -/* --- @f25519_pickn@ --- * - * - * Arguments: @f25519 *z@ = where to put the result - * @const f25519 *v@ = a table of entries - * @size_t n@ = the number of entries in @v@ - * @size_t i@ = an index - * - * Returns: --- - * - * Use: If @0 <= i < n < 32@ then set @z = v[i]@. If @n >= 32@ then - * do something unhelpful; otherwise, if @i >= n@ then set @z@ - * to zero. - */ - -extern void f25519_pickn(f25519 */*z*/, const f25519 */*v*/, size_t /*n*/, - size_t /*i*/); - -#endif - -/* --- @f25519_condswap@ --- * - * - * Arguments: @f25519 *x, *y@ = two operands - * @uint32 m@ = a mask - * - * Returns: --- - * - * Use: If @m@ is zero, do nothing; if @m@ is all-bits-set, then - * exchange @x@ and @y@. If @m@ has some other value, then - * scramble @x@ and @y@ in an unhelpful way. - */ - -extern void f25519_condswap(f25519 */*x*/, f25519 */*y*/, uint32 /*m*/); - -/* --- @f25519_add@ --- * - * - * Arguments: @f25519 *z@ = where to put the result (may alias @x@ or @y@) - * @const f25519 *x, *y@ = two operands - * - * Returns: --- - * - * Use: Set @z@ to the sum %$x + y$%. - */ - -extern void f25519_add(f25519 */*z*/, - const f25519 */*x*/, const f25519 */*y*/); - -/* --- @f25519_sub@ --- * - * - * Arguments: @f25519 *z@ = where to put the result (may alias @x@ or @y@) - * @const f25519 *x, *y@ = two operands - * - * Returns: --- - * - * Use: Set @z@ to the difference %$x - y$%. - */ - -extern void f25519_sub(f25519 */*z*/, - const f25519 */*x*/, const f25519 */*y*/); - -#ifndef F25519_TRIM_X25519 - -/* --- @f25519_neg@ --- * - * - * Arguments: @f25519 *z@ = where to put the result (may alias @x@) - * @const f25519 *x@ = an operand - * - * Returns: --- - * - * Use: Set @z = -x@. - */ - -extern void f25519_neg(f25519 */*z*/, const f25519 */*x*/); - -/* --- @f25519_condneg@ --- * - * - * Arguments: @f25519 *z@ = where to put the result (may alias @x@) - * @const f25519 *x@ = an operand - * @uint32 m@ = a mask - * - * Returns: --- - * - * Use: If @m@ is zero, set @z = x@; if @m@ is all-bits-set, then set - * @z = -x@. If @m@ has some other value then scramble @z@ in - * an unhelpful way. - */ - -extern void f25519_condneg(f25519 */*z*/, const f25519 */*x*/, uint32 /*m*/); - -#endif - -/* --- @f25519_mulconst@ --- * - * - * Arguments: @f25519 *z@ = where to put the result (may alias @x@) - * @const f25519 *x@ = an operand - * @long a@ = a small-ish constant; %$|a| < 2^{20}$%. - * - * Returns: --- - * - * Use: Set @z@ to the product %$a x$%. - */ - -extern void f25519_mulconst(f25519 */*z*/, const f25519 */*x*/, long /*a*/); - -/* --- @f25519_mul@ --- * - * - * Arguments: @f25519 *z@ = where to put the result (may alias @x@ or @y@) - * @const f25519 *x, *y@ = two operands - * - * Returns: --- - * - * Use: Set @z@ to the product %$x y$%. - */ - -extern void f25519_mul(f25519 */*z*/, - const f25519 */*x*/, const f25519 */*y*/); - -/* --- @f25519_sqr@ --- * - * - * Arguments: @f25519 *z@ = where to put the result (may alias @x@ or @y@) - * @const f25519 *x@ = an operand - * - * Returns: --- - * - * Use: Set @z@ to the square %$x^2$%. - */ - -extern void f25519_sqr(f25519 */*z*/, const f25519 */*x*/); - -/* --- @f25519_inv@ --- * - * - * Arguments: @f25519 *z@ = where to put the result (may alias @x@) - * @const f25519 *x@ = an operand - * - * Returns: --- - * - * Use: Stores in @z@ the multiplicative inverse %$x^{-1}$%. If - * %$x = 0$% then @z@ is set to zero. This is considered a - * feature. - */ - -extern void f25519_inv(f25519 */*z*/, const f25519 */*x*/); - -#ifndef F25519_TRIM_X25519 - -/* --- @f25519_quosqrt@ --- * - * - * Arguments: @f25519 *z@ = where to put the result (may alias @x@ or @y@) - * @const f25519 *x, *y@ = two operands - * - * Returns: Zero if successful, @-1@ if %$x/y$% is not a square. - * - * Use: Stores in @z@ the one of the square roots %$\pm\sqrt{x/y}$%. - * If %$x = y = 0% then the result is zero; if %$y = 0$% but %$x - * \ne 0$% then the operation fails. If you wanted a specific - * square root then you'll have to pick it yourself. - */ - -extern int f25519_quosqrt(f25519 */*z*/, - const f25519 */*x*/, const f25519 */*y*/); - -#endif - -/*----- That's all, folks -------------------------------------------------*/ - -#ifdef __cplusplus - } -#endif - -#endif