Bitcoin Core  0.20.99
P2P Digital Currency
field.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 http://www.opensource.org/licenses/mit-license.php.*
5  **********************************************************************/
6 
7 #ifndef SECP256K1_FIELD_H
8 #define SECP256K1_FIELD_H
9 
21 #if defined HAVE_CONFIG_H
22 #include "libsecp256k1-config.h"
23 #endif
24 
25 #if defined(USE_FIELD_10X26)
26 #include "field_10x26.h"
27 #elif defined(USE_FIELD_5X52)
28 #include "field_5x52.h"
29 #else
30 #error "Please select field implementation"
31 #endif
32 
33 #include "util.h"
34 
38 static void secp256k1_fe_normalize(secp256k1_fe *r);
39 
42 
45 
49 
53 
55 static void secp256k1_fe_set_int(secp256k1_fe *r, int a);
56 
58 static void secp256k1_fe_clear(secp256k1_fe *a);
59 
61 static int secp256k1_fe_is_zero(const secp256k1_fe *a);
62 
64 static int secp256k1_fe_is_odd(const secp256k1_fe *a);
65 
67 static int secp256k1_fe_equal(const secp256k1_fe *a, const secp256k1_fe *b);
68 
70 static int secp256k1_fe_equal_var(const secp256k1_fe *a, const secp256k1_fe *b);
71 
73 static int secp256k1_fe_cmp_var(const secp256k1_fe *a, const secp256k1_fe *b);
74 
76 static int secp256k1_fe_set_b32(secp256k1_fe *r, const unsigned char *a);
77 
79 static void secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe *a);
80 
83 static void secp256k1_fe_negate(secp256k1_fe *r, const secp256k1_fe *a, int m);
84 
87 static void secp256k1_fe_mul_int(secp256k1_fe *r, int a);
88 
90 static void secp256k1_fe_add(secp256k1_fe *r, const secp256k1_fe *a);
91 
94 static void secp256k1_fe_mul(secp256k1_fe *r, const secp256k1_fe *a, const secp256k1_fe * SECP256K1_RESTRICT b);
95 
98 static void secp256k1_fe_sqr(secp256k1_fe *r, const secp256k1_fe *a);
99 
105 static int secp256k1_fe_sqrt(secp256k1_fe *r, const secp256k1_fe *a);
106 
108 static int secp256k1_fe_is_quad_var(const secp256k1_fe *a);
109 
112 static void secp256k1_fe_inv(secp256k1_fe *r, const secp256k1_fe *a);
113 
115 static void secp256k1_fe_inv_var(secp256k1_fe *r, const secp256k1_fe *a);
116 
120 static void secp256k1_fe_inv_all_var(secp256k1_fe *r, const secp256k1_fe *a, size_t len);
121 
124 
127 
129 static void secp256k1_fe_storage_cmov(secp256k1_fe_storage *r, const secp256k1_fe_storage *a, int flag);
130 
132 static void secp256k1_fe_cmov(secp256k1_fe *r, const secp256k1_fe *a, int flag);
133 
134 #endif /* SECP256K1_FIELD_H */
static int secp256k1_fe_is_zero(const secp256k1_fe *a)
Verify whether a field element is zero.
static void secp256k1_fe_mul(secp256k1_fe *r, const secp256k1_fe *a, const secp256k1_fe *SECP256K1_RESTRICT b)
Sets a field element to be the product of two others.
static void secp256k1_fe_normalize_var(secp256k1_fe *r)
Normalize a field element, without constant-time guarantee.
static int secp256k1_fe_equal(const secp256k1_fe *a, const secp256k1_fe *b)
Compare two field elements.
static void secp256k1_fe_negate(secp256k1_fe *r, const secp256k1_fe *a, int m)
Set a field element equal to the additive inverse of another.
static void secp256k1_fe_from_storage(secp256k1_fe *r, const secp256k1_fe_storage *a)
Convert a field element back from the storage type.
static void secp256k1_fe_storage_cmov(secp256k1_fe_storage *r, const secp256k1_fe_storage *a, int flag)
If flag is true, set *r equal to *a; otherwise leave it.
static void secp256k1_fe_cmov(secp256k1_fe *r, const secp256k1_fe *a, int flag)
If flag is true, set *r equal to *a; otherwise leave it.
static void secp256k1_fe_set_int(secp256k1_fe *r, int a)
Set a field element equal to a small integer.
static void secp256k1_fe_to_storage(secp256k1_fe_storage *r, const secp256k1_fe *a)
Convert a field element to the storage type.
static void secp256k1_fe_clear(secp256k1_fe *a)
Sets a field element equal to zero, initializing all fields.
static void secp256k1_fe_add(secp256k1_fe *r, const secp256k1_fe *a)
Adds a field element to another.
static void secp256k1_fe_mul_int(secp256k1_fe *r, int a)
Multiplies the passed field element with a small integer constant.
static int secp256k1_fe_is_odd(const secp256k1_fe *a)
Check the "oddness" of a field element.
#define SECP256K1_RESTRICT
Definition: util.h:158
static int secp256k1_fe_is_quad_var(const secp256k1_fe *a)
Checks whether a field element is a quadratic residue.
static void secp256k1_fe_normalize_weak(secp256k1_fe *r)
Weakly normalize a field element: reduce its magnitude to 1, but don't fully normalize.
static int secp256k1_fe_normalizes_to_zero(secp256k1_fe *r)
Verify whether a field element represents zero i.e.
static void secp256k1_fe_inv_all_var(secp256k1_fe *r, const secp256k1_fe *a, size_t len)
Calculate the (modular) inverses of a batch of field elements.
static void secp256k1_fe_sqr(secp256k1_fe *r, const secp256k1_fe *a)
Sets a field element to be the square of another.
static int secp256k1_fe_set_b32(secp256k1_fe *r, const unsigned char *a)
Set a field element equal to 32-byte big endian value.
static int secp256k1_fe_cmp_var(const secp256k1_fe *a, const secp256k1_fe *b)
Compare two field elements.
static int secp256k1_fe_equal_var(const secp256k1_fe *a, const secp256k1_fe *b)
Same as secp256k1_fe_equal, but may be variable time.
static void secp256k1_fe_normalize(secp256k1_fe *r)
Field element module.
static void secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe *a)
Convert a field element to a 32-byte big endian value.
static int secp256k1_fe_sqrt(secp256k1_fe *r, const secp256k1_fe *a)
If a has a square root, it is computed in r and 1 is returned.
static void secp256k1_fe_inv_var(secp256k1_fe *r, const secp256k1_fe *a)
Potentially faster version of secp256k1_fe_inv, without constant-time guarantee.
static void secp256k1_fe_inv(secp256k1_fe *r, const secp256k1_fe *a)
Sets a field element to be the (modular) inverse of another.
static int secp256k1_fe_normalizes_to_zero_var(secp256k1_fe *r)
Verify whether a field element represents zero i.e.