/root/bitcoin/src/secp256k1/src/eckey_impl.h
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1 | | /*********************************************************************** |
2 | | * Copyright (c) 2013, 2014 Pieter Wuille * |
3 | | * Distributed under the MIT software license, see the accompanying * |
4 | | * file COPYING or https://www.opensource.org/licenses/mit-license.php.* |
5 | | ***********************************************************************/ |
6 | | |
7 | | #ifndef SECP256K1_ECKEY_IMPL_H |
8 | | #define SECP256K1_ECKEY_IMPL_H |
9 | | |
10 | | #include "eckey.h" |
11 | | |
12 | | #include "util.h" |
13 | | #include "scalar.h" |
14 | | #include "field.h" |
15 | | #include "group.h" |
16 | | #include "ecmult_gen.h" |
17 | | |
18 | 0 | static int secp256k1_eckey_pubkey_parse(secp256k1_ge *elem, const unsigned char *pub, size_t size) { |
19 | 0 | if (size == 33 && (pub[0] == SECP256K1_TAG_PUBKEY_EVEN || pub[0] == SECP256K1_TAG_PUBKEY_ODD)) { |
20 | 0 | secp256k1_fe x; |
21 | 0 | return secp256k1_fe_set_b32_limit(&x, pub+1) && secp256k1_ge_set_xo_var(elem, &x, pub[0] == SECP256K1_TAG_PUBKEY_ODD); |
22 | 0 | } else if (size == 65 && (pub[0] == SECP256K1_TAG_PUBKEY_UNCOMPRESSED || pub[0] == SECP256K1_TAG_PUBKEY_HYBRID_EVEN || pub[0] == SECP256K1_TAG_PUBKEY_HYBRID_ODD)) { |
23 | 0 | secp256k1_fe x, y; |
24 | 0 | if (!secp256k1_fe_set_b32_limit(&x, pub+1) || !secp256k1_fe_set_b32_limit(&y, pub+33)) { |
25 | 0 | return 0; |
26 | 0 | } |
27 | 0 | secp256k1_ge_set_xy(elem, &x, &y); |
28 | 0 | if ((pub[0] == SECP256K1_TAG_PUBKEY_HYBRID_EVEN || pub[0] == SECP256K1_TAG_PUBKEY_HYBRID_ODD) && |
29 | 0 | secp256k1_fe_is_odd(&y) != (pub[0] == SECP256K1_TAG_PUBKEY_HYBRID_ODD)) { |
30 | 0 | return 0; |
31 | 0 | } |
32 | 0 | return secp256k1_ge_is_valid_var(elem); |
33 | 0 | } else { |
34 | 0 | return 0; |
35 | 0 | } |
36 | 0 | } |
37 | | |
38 | 0 | static int secp256k1_eckey_pubkey_serialize(secp256k1_ge *elem, unsigned char *pub, size_t *size, int compressed) { |
39 | 0 | VERIFY_CHECK(compressed == 0 || compressed == 1); |
40 | |
|
41 | 0 | if (secp256k1_ge_is_infinity(elem)) { |
42 | 0 | return 0; |
43 | 0 | } |
44 | 0 | secp256k1_fe_normalize_var(&elem->x); |
45 | 0 | secp256k1_fe_normalize_var(&elem->y); |
46 | 0 | secp256k1_fe_get_b32(&pub[1], &elem->x); |
47 | 0 | if (compressed) { |
48 | 0 | *size = 33; |
49 | 0 | pub[0] = secp256k1_fe_is_odd(&elem->y) ? SECP256K1_TAG_PUBKEY_ODD : SECP256K1_TAG_PUBKEY_EVEN; |
50 | 0 | } else { |
51 | 0 | *size = 65; |
52 | 0 | pub[0] = SECP256K1_TAG_PUBKEY_UNCOMPRESSED; |
53 | 0 | secp256k1_fe_get_b32(&pub[33], &elem->y); |
54 | 0 | } |
55 | 0 | return 1; |
56 | 0 | } |
57 | | |
58 | 0 | static int secp256k1_eckey_privkey_tweak_add(secp256k1_scalar *key, const secp256k1_scalar *tweak) { |
59 | 0 | secp256k1_scalar_add(key, key, tweak); |
60 | 0 | return !secp256k1_scalar_is_zero(key); |
61 | 0 | } |
62 | | |
63 | 0 | static int secp256k1_eckey_pubkey_tweak_add(secp256k1_ge *key, const secp256k1_scalar *tweak) { |
64 | 0 | secp256k1_gej pt; |
65 | 0 | secp256k1_gej_set_ge(&pt, key); |
66 | 0 | secp256k1_ecmult(&pt, &pt, &secp256k1_scalar_one, tweak); |
67 | |
|
68 | 0 | if (secp256k1_gej_is_infinity(&pt)) { |
69 | 0 | return 0; |
70 | 0 | } |
71 | 0 | secp256k1_ge_set_gej(key, &pt); |
72 | 0 | return 1; |
73 | 0 | } |
74 | | |
75 | 0 | static int secp256k1_eckey_privkey_tweak_mul(secp256k1_scalar *key, const secp256k1_scalar *tweak) { |
76 | 0 | int ret; |
77 | 0 | ret = !secp256k1_scalar_is_zero(tweak); |
78 | |
|
79 | 0 | secp256k1_scalar_mul(key, key, tweak); |
80 | 0 | return ret; |
81 | 0 | } |
82 | | |
83 | 0 | static int secp256k1_eckey_pubkey_tweak_mul(secp256k1_ge *key, const secp256k1_scalar *tweak) { |
84 | 0 | secp256k1_gej pt; |
85 | 0 | if (secp256k1_scalar_is_zero(tweak)) { |
86 | 0 | return 0; |
87 | 0 | } |
88 | | |
89 | 0 | secp256k1_gej_set_ge(&pt, key); |
90 | 0 | secp256k1_ecmult(&pt, &pt, tweak, &secp256k1_scalar_zero); |
91 | 0 | secp256k1_ge_set_gej(key, &pt); |
92 | 0 | return 1; |
93 | 0 | } |
94 | | |
95 | | #endif /* SECP256K1_ECKEY_IMPL_H */ |