diff options
Diffstat (limited to 'crypto/secp256k1/libsecp256k1/src/field.h')
| -rw-r--r-- | crypto/secp256k1/libsecp256k1/src/field.h | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/crypto/secp256k1/libsecp256k1/src/field.h b/crypto/secp256k1/libsecp256k1/src/field.h index 311329b92..bbb1ee866 100644 --- a/crypto/secp256k1/libsecp256k1/src/field.h +++ b/crypto/secp256k1/libsecp256k1/src/field.h @@ -10,7 +10,7 @@ /** Field element module. * * Field elements can be represented in several ways, but code accessing - * it (and implementations) need to take certain properaties into account: + * it (and implementations) need to take certain properties into account: * - Each field element can be normalized or not. * - Each field element has a magnitude, which represents how far away * its representation is away from normalization. Normalized elements @@ -30,6 +30,8 @@ #error "Please select field implementation" #endif +#include "util.h" + /** Normalize a field element. */ static void secp256k1_fe_normalize(secp256k1_fe *r); @@ -50,6 +52,9 @@ static int secp256k1_fe_normalizes_to_zero_var(secp256k1_fe *r); /** Set a field element equal to a small integer. Resulting field element is normalized. */ static void secp256k1_fe_set_int(secp256k1_fe *r, int a); +/** Sets a field element equal to zero, initializing all fields. */ +static void secp256k1_fe_clear(secp256k1_fe *a); + /** Verify whether a field element is zero. Requires the input to be normalized. */ static int secp256k1_fe_is_zero(const secp256k1_fe *a); @@ -57,6 +62,9 @@ static int secp256k1_fe_is_zero(const secp256k1_fe *a); static int secp256k1_fe_is_odd(const secp256k1_fe *a); /** Compare two field elements. Requires magnitude-1 inputs. */ +static int secp256k1_fe_equal(const secp256k1_fe *a, const secp256k1_fe *b); + +/** Same as secp256k1_fe_equal, but may be variable time. */ static int secp256k1_fe_equal_var(const secp256k1_fe *a, const secp256k1_fe *b); /** Compare two field elements. Requires both inputs to be normalized */ @@ -87,10 +95,15 @@ static void secp256k1_fe_mul(secp256k1_fe *r, const secp256k1_fe *a, const secp2 * The output magnitude is 1 (but not guaranteed to be normalized). */ static void secp256k1_fe_sqr(secp256k1_fe *r, const secp256k1_fe *a); -/** Sets a field element to be the (modular) square root (if any exist) of another. Requires the - * input's magnitude to be at most 8. The output magnitude is 1 (but not guaranteed to be - * normalized). Return value indicates whether a square root was found. */ -static int secp256k1_fe_sqrt_var(secp256k1_fe *r, const secp256k1_fe *a); +/** If a has a square root, it is computed in r and 1 is returned. If a does not + * have a square root, the root of its negation is computed and 0 is returned. + * The input's magnitude can be at most 8. The output magnitude is 1 (but not + * guaranteed to be normalized). The result in r will always be a square + * itself. */ +static int secp256k1_fe_sqrt(secp256k1_fe *r, const secp256k1_fe *a); + +/** Checks whether a field element is a quadratic residue. */ +static int secp256k1_fe_is_quad_var(const secp256k1_fe *a); /** Sets a field element to be the (modular) inverse of another. Requires the input's magnitude to be * at most 8. The output magnitude is 1 (but not guaranteed to be normalized). */ @@ -102,7 +115,7 @@ static void secp256k1_fe_inv_var(secp256k1_fe *r, const secp256k1_fe *a); /** Calculate the (modular) inverses of a batch of field elements. Requires the inputs' magnitudes to be * at most 8. The output magnitudes are 1 (but not guaranteed to be normalized). The inputs and * outputs must not overlap in memory. */ -static void secp256k1_fe_inv_all_var(size_t len, secp256k1_fe *r, const secp256k1_fe *a); +static void secp256k1_fe_inv_all_var(secp256k1_fe *r, const secp256k1_fe *a, size_t len); /** Convert a field element to the storage type. */ static void secp256k1_fe_to_storage(secp256k1_fe_storage *r, const secp256k1_fe *a); |