97 lines
3.9 KiB
C
97 lines
3.9 KiB
C
/***********************************************************************
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* Copyright (c) 2013, 2014 Pieter Wuille *
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* Distributed under the MIT software license, see the accompanying *
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* file COPYING or https://www.opensource.org/licenses/mit-license.php.*
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***********************************************************************/
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#ifndef SECP256K1_ECKEY_IMPL_H
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#define SECP256K1_ECKEY_IMPL_H
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#include "eckey.h"
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#include "scalar.h"
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#include "field.h"
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#include "group.h"
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#include "ecmult_gen.h"
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static int rustsecp256k1_v0_4_1_eckey_pubkey_parse(rustsecp256k1_v0_4_1_ge *elem, const unsigned char *pub, size_t size) {
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if (size == 33 && (pub[0] == SECP256K1_TAG_PUBKEY_EVEN || pub[0] == SECP256K1_TAG_PUBKEY_ODD)) {
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rustsecp256k1_v0_4_1_fe x;
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return rustsecp256k1_v0_4_1_fe_set_b32(&x, pub+1) && rustsecp256k1_v0_4_1_ge_set_xo_var(elem, &x, pub[0] == SECP256K1_TAG_PUBKEY_ODD);
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} else if (size == 65 && (pub[0] == SECP256K1_TAG_PUBKEY_UNCOMPRESSED || pub[0] == SECP256K1_TAG_PUBKEY_HYBRID_EVEN || pub[0] == SECP256K1_TAG_PUBKEY_HYBRID_ODD)) {
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rustsecp256k1_v0_4_1_fe x, y;
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if (!rustsecp256k1_v0_4_1_fe_set_b32(&x, pub+1) || !rustsecp256k1_v0_4_1_fe_set_b32(&y, pub+33)) {
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return 0;
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}
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rustsecp256k1_v0_4_1_ge_set_xy(elem, &x, &y);
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if ((pub[0] == SECP256K1_TAG_PUBKEY_HYBRID_EVEN || pub[0] == SECP256K1_TAG_PUBKEY_HYBRID_ODD) &&
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rustsecp256k1_v0_4_1_fe_is_odd(&y) != (pub[0] == SECP256K1_TAG_PUBKEY_HYBRID_ODD)) {
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return 0;
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}
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return rustsecp256k1_v0_4_1_ge_is_valid_var(elem);
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} else {
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return 0;
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}
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}
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static int rustsecp256k1_v0_4_1_eckey_pubkey_serialize(rustsecp256k1_v0_4_1_ge *elem, unsigned char *pub, size_t *size, int compressed) {
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if (rustsecp256k1_v0_4_1_ge_is_infinity(elem)) {
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return 0;
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}
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rustsecp256k1_v0_4_1_fe_normalize_var(&elem->x);
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rustsecp256k1_v0_4_1_fe_normalize_var(&elem->y);
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rustsecp256k1_v0_4_1_fe_get_b32(&pub[1], &elem->x);
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if (compressed) {
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*size = 33;
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pub[0] = rustsecp256k1_v0_4_1_fe_is_odd(&elem->y) ? SECP256K1_TAG_PUBKEY_ODD : SECP256K1_TAG_PUBKEY_EVEN;
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} else {
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*size = 65;
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pub[0] = SECP256K1_TAG_PUBKEY_UNCOMPRESSED;
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rustsecp256k1_v0_4_1_fe_get_b32(&pub[33], &elem->y);
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}
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return 1;
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}
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static int rustsecp256k1_v0_4_1_eckey_privkey_tweak_add(rustsecp256k1_v0_4_1_scalar *key, const rustsecp256k1_v0_4_1_scalar *tweak) {
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rustsecp256k1_v0_4_1_scalar_add(key, key, tweak);
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return !rustsecp256k1_v0_4_1_scalar_is_zero(key);
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}
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static int rustsecp256k1_v0_4_1_eckey_pubkey_tweak_add(const rustsecp256k1_v0_4_1_ecmult_context *ctx, rustsecp256k1_v0_4_1_ge *key, const rustsecp256k1_v0_4_1_scalar *tweak) {
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rustsecp256k1_v0_4_1_gej pt;
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rustsecp256k1_v0_4_1_scalar one;
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rustsecp256k1_v0_4_1_gej_set_ge(&pt, key);
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rustsecp256k1_v0_4_1_scalar_set_int(&one, 1);
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rustsecp256k1_v0_4_1_ecmult(ctx, &pt, &pt, &one, tweak);
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if (rustsecp256k1_v0_4_1_gej_is_infinity(&pt)) {
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return 0;
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}
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rustsecp256k1_v0_4_1_ge_set_gej(key, &pt);
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return 1;
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}
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static int rustsecp256k1_v0_4_1_eckey_privkey_tweak_mul(rustsecp256k1_v0_4_1_scalar *key, const rustsecp256k1_v0_4_1_scalar *tweak) {
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int ret;
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ret = !rustsecp256k1_v0_4_1_scalar_is_zero(tweak);
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rustsecp256k1_v0_4_1_scalar_mul(key, key, tweak);
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return ret;
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}
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static int rustsecp256k1_v0_4_1_eckey_pubkey_tweak_mul(const rustsecp256k1_v0_4_1_ecmult_context *ctx, rustsecp256k1_v0_4_1_ge *key, const rustsecp256k1_v0_4_1_scalar *tweak) {
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rustsecp256k1_v0_4_1_scalar zero;
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rustsecp256k1_v0_4_1_gej pt;
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if (rustsecp256k1_v0_4_1_scalar_is_zero(tweak)) {
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return 0;
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}
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rustsecp256k1_v0_4_1_scalar_set_int(&zero, 0);
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rustsecp256k1_v0_4_1_gej_set_ge(&pt, key);
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rustsecp256k1_v0_4_1_ecmult(ctx, &pt, &pt, tweak, &zero);
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rustsecp256k1_v0_4_1_ge_set_gej(key, &pt);
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return 1;
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}
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#endif /* SECP256K1_ECKEY_IMPL_H */
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