diff options
Diffstat (limited to 'src/secp256k1/src/field.h')
| -rw-r--r-- | src/secp256k1/src/field.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/src/secp256k1/src/field.h b/src/secp256k1/src/field.h index 55679a2fc1..2584a494ee 100644 --- a/src/secp256k1/src/field.h +++ b/src/secp256k1/src/field.h @@ -32,6 +32,12 @@ #error "Please select wide multiplication implementation" #endif +static const secp256k1_fe secp256k1_fe_one = SECP256K1_FE_CONST(0, 0, 0, 0, 0, 0, 0, 1); +static const secp256k1_fe secp256k1_const_beta = SECP256K1_FE_CONST( + 0x7ae96a2bul, 0x657c0710ul, 0x6e64479eul, 0xac3434e9ul, + 0x9cf04975ul, 0x12f58995ul, 0xc1396c28ul, 0x719501eeul +); + /** Normalize a field element. This brings the field element to a canonical representation, reduces * its magnitude to 1, and reduces it modulo field size `p`. */ @@ -124,4 +130,13 @@ static void secp256k1_fe_storage_cmov(secp256k1_fe_storage *r, const secp256k1_f /** If flag is true, set *r equal to *a; otherwise leave it. Constant-time. Both *r and *a must be initialized.*/ static void secp256k1_fe_cmov(secp256k1_fe *r, const secp256k1_fe *a, int flag); +/** Halves the value of a field element modulo the field prime. Constant-time. + * For an input magnitude 'm', the output magnitude is set to 'floor(m/2) + 1'. + * The output is not guaranteed to be normalized, regardless of the input. */ +static void secp256k1_fe_half(secp256k1_fe *r); + +/** Sets each limb of 'r' to its upper bound at magnitude 'm'. The output will also have its + * magnitude set to 'm' and is normalized if (and only if) 'm' is zero. */ +static void secp256k1_fe_get_bounds(secp256k1_fe *r, int m); + #endif /* SECP256K1_FIELD_H */ |