| /*********************************************************************** | |
| * Copyright (c) 2013, 2014 Pieter Wuille * | |
| * Distributed under the MIT software license, see the accompanying * | |
| * file COPYING or https://www.opensource.org/licenses/mit-license.php.* | |
| ***********************************************************************/ | |
| | |
| #ifndef SECP256K1_ECKEY_IMPL_H | |
| #define SECP256K1_ECKEY_IMPL_H | |
| | |
| #include "eckey.h" | |
| | |
| #include "util.h" | |
| #include "scalar.h" | |
| #include "field.h" | |
| #include "group.h" | |
| #include "ecmult_gen.h" | |
| | |
| static int secp256k1_eckey_pubkey_parse(secp256k1_ge *elem, const unsigned char *pub, size_t size) { | |
| if (size == 33 && (pub[0] == SECP256K1_TAG_PUBKEY_EVEN || pub[0] == SECP256K1_TAG_PUBKEY_ODD)) { | |
| secp256k1_fe x; | |
| return secp256k1_fe_set_b32_limit(&x, pub+1) && secp256k1_ge_set_xo_var(elem, &x, pub[0] == SECP256K1_TAG_PUBKEY_ODD); | |
| } else if (size == 65 && (pub[0] == SECP256K1_TAG_PUBKEY_UNCOMPRESSED || pub[0] == SECP256K1_TAG_PUBKEY_HYBRID_EVEN || pub[0] == SECP256K1_TAG_PUBKEY_HYBRID_ODD)) { | |
| secp256k1_fe x, y; | |
| if (!secp256k1_fe_set_b32_limit(&x, pub+1) || !secp256k1_fe_set_b32_limit(&y, pub+33)) { | |
| return 0; | |
| } | |
| secp256k1_ge_set_xy(elem, &x, &y); | |
| if ((pub[0] == SECP256K1_TAG_PUBKEY_HYBRID_EVEN || pub[0] == SECP256K1_TAG_PUBKEY_HYBRID_ODD) && | |
| secp256k1_fe_is_odd(&y) != (pub[0] == SECP256K1_TAG_PUBKEY_HYBRID_ODD)) { | |
| return 0; | |
| } | |
| return secp256k1_ge_is_valid_var(elem); | |
| } else { | |
| return 0; | |
| } | |
| } | |
| | |
| static int secp256k1_eckey_pubkey_serialize(secp256k1_ge *elem, unsigned char *pub, size_t *size, int compressed) { | |
| VERIFY_CHECK(compressed == 0 || compressed == 1); | |
| | |
| if (secp256k1_ge_is_infinity(elem)) { | |
| return 0; | |
| } | |
| secp256k1_fe_normalize_var(&elem->x); | |
| secp256k1_fe_normalize_var(&elem->y); | |
| secp256k1_fe_get_b32(&pub[1], &elem->x); | |
| if (compressed) { | |
| *size = 33; | |
| pub[0] = secp256k1_fe_is_odd(&elem->y) ? SECP256K1_TAG_PUBKEY_ODD : SECP256K1_TAG_PUBKEY_EVEN; | |
| } else { | |
| *size = 65; | |
| pub[0] = SECP256K1_TAG_PUBKEY_UNCOMPRESSED; | |
| secp256k1_fe_get_b32(&pub[33], &elem->y); | |
| } | |
| return 1; | |
| } | |
| | |
| static int secp256k1_eckey_privkey_tweak_add(secp256k1_scalar *key, const secp256k1_scalar *tweak) { | |
| secp256k1_scalar_add(key, key, tweak); | |
| return !secp256k1_scalar_is_zero(key); | |
| } | |
| | |
| static int secp256k1_eckey_pubkey_tweak_add(secp256k1_ge *key, const secp256k1_scalar *tweak) { | |
| secp256k1_gej pt; | |
| secp256k1_gej_set_ge(&pt, key); | |
| secp256k1_ecmult(&pt, &pt, &secp256k1_scalar_one, tweak); | |
| | |
| if (secp256k1_gej_is_infinity(&pt)) { | |
| return 0; | |
| } | |
| secp256k1_ge_set_gej(key, &pt); | |
| return 1; | |
| } | |
| | |
| static int secp256k1_eckey_privkey_tweak_mul(secp256k1_scalar *key, const secp256k1_scalar *tweak) { | |
| int ret; | |
| ret = !secp256k1_scalar_is_zero(tweak); | |
| | |
| secp256k1_scalar_mul(key, key, tweak); | |
| return ret; | |
| } | |
| | |
| static int secp256k1_eckey_pubkey_tweak_mul(secp256k1_ge *key, const secp256k1_scalar *tweak) { | |
| secp256k1_gej pt; | |
| if (secp256k1_scalar_is_zero(tweak)) { | |
| Taking false branch | |
| Assuming the condition is false | |
| return 0; | |
| } | |
| | |
| secp256k1_gej_set_ge(&pt, key); | |
| secp256k1_ecmult(&pt, &pt, tweak, &secp256k1_scalar_zero); | |
| Calling 'secp256k1_ecmult' | |
| secp256k1_ge_set_gej(key, &pt); | |
| return 1; | |
| } | |
| | |
| #endif /* SECP256K1_ECKEY_IMPL_H */ | |