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Diff: wolfcrypt/src/ge_low_mem.c
- Revision:
- 17:ff9d1e86ad5f
- Parent:
- 16:048e5e270a58
diff -r 048e5e270a58 -r ff9d1e86ad5f wolfcrypt/src/ge_low_mem.c --- a/wolfcrypt/src/ge_low_mem.c Tue Nov 19 14:32:16 2019 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,564 +0,0 @@ -/* ge_low_mem.c - * - * Copyright (C) 2006-2017 wolfSSL Inc. - * - * This file is part of wolfSSL. - * - * wolfSSL is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * wolfSSL 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, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA - */ - - - /* Based from Daniel Beer's public domain work. */ - -#ifdef HAVE_CONFIG_H - #include <config.h> -#endif - -#include <wolfssl/wolfcrypt/settings.h> - -#ifdef HAVE_ED25519 -#ifdef ED25519_SMALL /* use slower code that takes less memory */ - -#include <wolfssl/wolfcrypt/ge_operations.h> -#include <wolfssl/wolfcrypt/error-crypt.h> -#ifdef NO_INLINE - #include <wolfssl/wolfcrypt/misc.h> -#else - #define WOLFSSL_MISC_INCLUDED - #include <wolfcrypt/src/misc.c> -#endif - -void ed25519_smult(ge_p3 *r, const ge_p3 *a, const byte *e); -void ed25519_add(ge_p3 *r, const ge_p3 *a, const ge_p3 *b); -void ed25519_double(ge_p3 *r, const ge_p3 *a); - - -static const byte ed25519_order[F25519_SIZE] = { - 0xed, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58, - 0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14, - 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, - 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10 -}; - -/*Arithmetic modulo the group order m = 2^252 + - 27742317777372353535851937790883648493 = - 7237005577332262213973186563042994240857116359379907606001950938285454250989 */ - -static const word32 m[32] = { - 0xED,0xD3,0xF5,0x5C,0x1A,0x63,0x12,0x58,0xD6,0x9C,0xF7,0xA2,0xDE,0xF9, - 0xDE,0x14,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, - 0x00,0x00,0x00,0x10 -}; - -static const word32 mu[33] = { - 0x1B,0x13,0x2C,0x0A,0xA3,0xE5,0x9C,0xED,0xA7,0x29,0x63,0x08,0x5D,0x21, - 0x06,0x21,0xEB,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, - 0xFF,0xFF,0xFF,0xFF,0x0F -}; - - -int ge_compress_key(byte* out, const byte* xIn, const byte* yIn, - word32 keySz) -{ - byte tmp[F25519_SIZE]; - byte parity; - byte pt[32]; - int i; - - lm_copy(tmp, xIn); - parity = (tmp[0] & 1) << 7; - - lm_copy(pt, yIn); - pt[31] |= parity; - - for(i = 0; i < 32; i++) { - out[32-i-1] = pt[i]; - } - (void)keySz; - return 0; -} - - -static word32 lt(word32 a,word32 b) /* 16-bit inputs */ -{ - unsigned int x = a; - x -= (unsigned int) b; /* 0..65535: no; 4294901761..4294967295: yes */ - x >>= 31; /* 0: no; 1: yes */ - return x; -} - - -/* Reduce coefficients of r before calling reduce_add_sub */ -static void reduce_add_sub(word32 *r) -{ - word32 pb = 0; - word32 b; - word32 mask; - int i; - unsigned char t[32]; - - for(i=0;i<32;i++) - { - pb += m[i]; - b = lt(r[i],pb); - t[i] = r[i]-pb+(b<<8); - pb = b; - } - mask = b - 1; - for(i=0;i<32;i++) - r[i] ^= mask & (r[i] ^ t[i]); -} - - -/* Reduce coefficients of x before calling barrett_reduce */ -static void barrett_reduce(word32* r, word32 x[64]) -{ - /* See HAC, Alg. 14.42 */ - int i,j; - word32 q2[66]; - word32 *q3 = q2 + 33; - word32 r1[33]; - word32 r2[33]; - word32 carry; - word32 pb = 0; - word32 b; - - for (i = 0;i < 66;++i) q2[i] = 0; - for (i = 0;i < 33;++i) r2[i] = 0; - - for(i=0;i<33;i++) - for(j=0;j<33;j++) - if(i+j >= 31) q2[i+j] += mu[i]*x[j+31]; - carry = q2[31] >> 8; - q2[32] += carry; - carry = q2[32] >> 8; - q2[33] += carry; - - for(i=0;i<33;i++)r1[i] = x[i]; - for(i=0;i<32;i++) - for(j=0;j<33;j++) - if(i+j < 33) r2[i+j] += m[i]*q3[j]; - - for(i=0;i<32;i++) - { - carry = r2[i] >> 8; - r2[i+1] += carry; - r2[i] &= 0xff; - } - - for(i=0;i<32;i++) - { - pb += r2[i]; - b = lt(r1[i],pb); - r[i] = r1[i]-pb+(b<<8); - pb = b; - } - - /* XXX: Can it really happen that r<0?, See HAC, Alg 14.42, Step 3 - * r is an unsigned type. - * If so: Handle it here! - */ - - reduce_add_sub(r); - reduce_add_sub(r); -} - - -void sc_reduce(unsigned char x[64]) -{ - int i; - word32 t[64]; - word32 r[32]; - for(i=0;i<64;i++) t[i] = x[i]; - barrett_reduce(r, t); - for(i=0;i<32;i++) x[i] = (r[i] & 0xFF); -} - - -void sc_muladd(byte* out, const byte* a, const byte* b, const byte* c) -{ - - byte s[32]; - byte e[64]; - - XMEMSET(e, 0, sizeof(e)); - XMEMCPY(e, b, 32); - - /* Obtain e */ - sc_reduce(e); - - /* Compute s = ze + k */ - fprime_mul(s, a, e, ed25519_order); - fprime_add(s, c, ed25519_order); - - XMEMCPY(out, s, 32); -} - - -/* Base point is (numbers wrapped): - * - * x = 151122213495354007725011514095885315114 - * 54012693041857206046113283949847762202 - * y = 463168356949264781694283940034751631413 - * 07993866256225615783033603165251855960 - * - * y is derived by transforming the original Montgomery base (u=9). x - * is the corresponding positive coordinate for the new curve equation. - * t is x*y. - */ -const ge_p3 ed25519_base = { - { - 0x1a, 0xd5, 0x25, 0x8f, 0x60, 0x2d, 0x56, 0xc9, - 0xb2, 0xa7, 0x25, 0x95, 0x60, 0xc7, 0x2c, 0x69, - 0x5c, 0xdc, 0xd6, 0xfd, 0x31, 0xe2, 0xa4, 0xc0, - 0xfe, 0x53, 0x6e, 0xcd, 0xd3, 0x36, 0x69, 0x21 - }, - { - 0x58, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, - 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, - 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, - 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66 - }, - {1, 0}, - { - 0xa3, 0xdd, 0xb7, 0xa5, 0xb3, 0x8a, 0xde, 0x6d, - 0xf5, 0x52, 0x51, 0x77, 0x80, 0x9f, 0xf0, 0x20, - 0x7d, 0xe3, 0xab, 0x64, 0x8e, 0x4e, 0xea, 0x66, - 0x65, 0x76, 0x8b, 0xd7, 0x0f, 0x5f, 0x87, 0x67 - }, - -}; - - -const ge_p3 ed25519_neutral = { - {0}, - {1, 0}, - {1, 0}, - {0}, - -}; - - -static const byte ed25519_d[F25519_SIZE] = { - 0xa3, 0x78, 0x59, 0x13, 0xca, 0x4d, 0xeb, 0x75, - 0xab, 0xd8, 0x41, 0x41, 0x4d, 0x0a, 0x70, 0x00, - 0x98, 0xe8, 0x79, 0x77, 0x79, 0x40, 0xc7, 0x8c, - 0x73, 0xfe, 0x6f, 0x2b, 0xee, 0x6c, 0x03, 0x52 -}; - - -/* k = 2d */ -static const byte ed25519_k[F25519_SIZE] = { - 0x59, 0xf1, 0xb2, 0x26, 0x94, 0x9b, 0xd6, 0xeb, - 0x56, 0xb1, 0x83, 0x82, 0x9a, 0x14, 0xe0, 0x00, - 0x30, 0xd1, 0xf3, 0xee, 0xf2, 0x80, 0x8e, 0x19, - 0xe7, 0xfc, 0xdf, 0x56, 0xdc, 0xd9, 0x06, 0x24 -}; - - -void ed25519_add(ge_p3 *r, - const ge_p3 *p1, const ge_p3 *p2) -{ - /* Explicit formulas database: add-2008-hwcd-3 - * - * source 2008 Hisil--Wong--Carter--Dawson, - * http://eprint.iacr.org/2008/522, Section 3.1 - * appliesto extended-1 - * parameter k - * assume k = 2 d - * compute A = (Y1-X1)(Y2-X2) - * compute B = (Y1+X1)(Y2+X2) - * compute C = T1 k T2 - * compute D = Z1 2 Z2 - * compute E = B - A - * compute F = D - C - * compute G = D + C - * compute H = B + A - * compute X3 = E F - * compute Y3 = G H - * compute T3 = E H - * compute Z3 = F G - */ - byte a[F25519_SIZE]; - byte b[F25519_SIZE]; - byte c[F25519_SIZE]; - byte d[F25519_SIZE]; - byte e[F25519_SIZE]; - byte f[F25519_SIZE]; - byte g[F25519_SIZE]; - byte h[F25519_SIZE]; - - /* A = (Y1-X1)(Y2-X2) */ - lm_sub(c, p1->Y, p1->X); - lm_sub(d, p2->Y, p2->X); - fe_mul__distinct(a, c, d); - - /* B = (Y1+X1)(Y2+X2) */ - lm_add(c, p1->Y, p1->X); - lm_add(d, p2->Y, p2->X); - fe_mul__distinct(b, c, d); - - /* C = T1 k T2 */ - fe_mul__distinct(d, p1->T, p2->T); - fe_mul__distinct(c, d, ed25519_k); - - /* D = Z1 2 Z2 */ - fe_mul__distinct(d, p1->Z, p2->Z); - lm_add(d, d, d); - - /* E = B - A */ - lm_sub(e, b, a); - - /* F = D - C */ - lm_sub(f, d, c); - - /* G = D + C */ - lm_add(g, d, c); - - /* H = B + A */ - lm_add(h, b, a); - - /* X3 = E F */ - fe_mul__distinct(r->X, e, f); - - /* Y3 = G H */ - fe_mul__distinct(r->Y, g, h); - - /* T3 = E H */ - fe_mul__distinct(r->T, e, h); - - /* Z3 = F G */ - fe_mul__distinct(r->Z, f, g); -} - - -void ed25519_double(ge_p3 *r, const ge_p3 *p) -{ - /* Explicit formulas database: dbl-2008-hwcd - * - * source 2008 Hisil--Wong--Carter--Dawson, - * http://eprint.iacr.org/2008/522, Section 3.3 - * compute A = X1^2 - * compute B = Y1^2 - * compute C = 2 Z1^2 - * compute D = a A - * compute E = (X1+Y1)^2-A-B - * compute G = D + B - * compute F = G - C - * compute H = D - B - * compute X3 = E F - * compute Y3 = G H - * compute T3 = E H - * compute Z3 = F G - */ - byte a[F25519_SIZE]; - byte b[F25519_SIZE]; - byte c[F25519_SIZE]; - byte e[F25519_SIZE]; - byte f[F25519_SIZE]; - byte g[F25519_SIZE]; - byte h[F25519_SIZE]; - - /* A = X1^2 */ - fe_mul__distinct(a, p->X, p->X); - - /* B = Y1^2 */ - fe_mul__distinct(b, p->Y, p->Y); - - /* C = 2 Z1^2 */ - fe_mul__distinct(c, p->Z, p->Z); - lm_add(c, c, c); - - /* D = a A (alter sign) */ - /* E = (X1+Y1)^2-A-B */ - lm_add(f, p->X, p->Y); - fe_mul__distinct(e, f, f); - lm_sub(e, e, a); - lm_sub(e, e, b); - - /* G = D + B */ - lm_sub(g, b, a); - - /* F = G - C */ - lm_sub(f, g, c); - - /* H = D - B */ - lm_neg(h, b); - lm_sub(h, h, a); - - /* X3 = E F */ - fe_mul__distinct(r->X, e, f); - - /* Y3 = G H */ - fe_mul__distinct(r->Y, g, h); - - /* T3 = E H */ - fe_mul__distinct(r->T, e, h); - - /* Z3 = F G */ - fe_mul__distinct(r->Z, f, g); -} - - -void ed25519_smult(ge_p3 *r_out, const ge_p3 *p, const byte *e) -{ - ge_p3 r; - int i; - - XMEMCPY(&r, &ed25519_neutral, sizeof(r)); - - for (i = 255; i >= 0; i--) { - const byte bit = (e[i >> 3] >> (i & 7)) & 1; - ge_p3 s; - - ed25519_double(&r, &r); - ed25519_add(&s, &r, p); - - fe_select(r.X, r.X, s.X, bit); - fe_select(r.Y, r.Y, s.Y, bit); - fe_select(r.Z, r.Z, s.Z, bit); - fe_select(r.T, r.T, s.T, bit); - } - XMEMCPY(r_out, &r, sizeof(r)); -} - - -void ge_scalarmult_base(ge_p3 *R,const unsigned char *nonce) -{ - ed25519_smult(R, &ed25519_base, nonce); -} - - -/* pack the point h into array s */ -void ge_p3_tobytes(unsigned char *s,const ge_p3 *h) -{ - byte x[F25519_SIZE]; - byte y[F25519_SIZE]; - byte z1[F25519_SIZE]; - byte parity; - - fe_inv__distinct(z1, h->Z); - fe_mul__distinct(x, h->X, z1); - fe_mul__distinct(y, h->Y, z1); - - fe_normalize(x); - fe_normalize(y); - - parity = (x[0] & 1) << 7; - lm_copy(s, y); - fe_normalize(s); - s[31] |= parity; -} - - -/* pack the point h into array s */ -void ge_tobytes(unsigned char *s,const ge_p2 *h) -{ - byte x[F25519_SIZE]; - byte y[F25519_SIZE]; - byte z1[F25519_SIZE]; - byte parity; - - fe_inv__distinct(z1, h->Z); - fe_mul__distinct(x, h->X, z1); - fe_mul__distinct(y, h->Y, z1); - - fe_normalize(x); - fe_normalize(y); - - parity = (x[0] & 1) << 7; - lm_copy(s, y); - fe_normalize(s); - s[31] |= parity; -} - - -/* - Test if the public key can be uncompressed and negate it (-X,Y,Z,-T) - return 0 on success - */ -int ge_frombytes_negate_vartime(ge_p3 *p,const unsigned char *s) -{ - - byte parity; - byte x[F25519_SIZE]; - byte y[F25519_SIZE]; - byte a[F25519_SIZE]; - byte b[F25519_SIZE]; - byte c[F25519_SIZE]; - int ret = 0; - - /* unpack the key s */ - parity = s[31] >> 7; - lm_copy(y, s); - y[31] &= 127; - - fe_mul__distinct(c, y, y); - fe_mul__distinct(b, c, ed25519_d); - lm_add(a, b, f25519_one); - fe_inv__distinct(b, a); - lm_sub(a, c, f25519_one); - fe_mul__distinct(c, a, b); - fe_sqrt(a, c); - lm_neg(b, a); - fe_select(x, a, b, (a[0] ^ parity) & 1); - - /* test that x^2 is equal to c */ - fe_mul__distinct(a, x, x); - fe_normalize(a); - fe_normalize(c); - ret |= ConstantCompare(a, c, F25519_SIZE); - - /* project the key s onto p */ - lm_copy(p->X, x); - lm_copy(p->Y, y); - fe_load(p->Z, 1); - fe_mul__distinct(p->T, x, y); - - /* negate, the point becomes (-X,Y,Z,-T) */ - lm_neg(p->X,p->X); - lm_neg(p->T,p->T); - - return ret; -} - - -int ge_double_scalarmult_vartime(ge_p2* R, const unsigned char *h, - const ge_p3 *inA,const unsigned char *sig) -{ - ge_p3 p, A; - int ret = 0; - - XMEMCPY(&A, inA, sizeof(ge_p3)); - - /* find SB */ - ed25519_smult(&p, &ed25519_base, sig); - - /* find H(R,A,M) * -A */ - ed25519_smult(&A, &A, h); - - /* SB + -H(R,A,M)A */ - ed25519_add(&A, &p, &A); - - lm_copy(R->X, A.X); - lm_copy(R->Y, A.Y); - lm_copy(R->Z, A.Z); - - return ret; -} - -#endif /* ED25519_SMALL */ -#endif /* HAVE_ED25519 */ -