diff options
Diffstat (limited to 'src/scalar.h')
| -rw-r--r-- | src/scalar.h | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/src/scalar.h b/src/scalar.h index 59304cb66e..2a74703523 100644 --- a/src/scalar.h +++ b/src/scalar.h @@ -32,9 +32,17 @@ static unsigned int secp256k1_scalar_get_bits(const secp256k1_scalar *a, unsigne /** Access bits from a scalar. Not constant time. */ static unsigned int secp256k1_scalar_get_bits_var(const secp256k1_scalar *a, unsigned int offset, unsigned int count); -/** Set a scalar from a big endian byte array. */ +/** Set a scalar from a big endian byte array. The scalar will be reduced modulo group order `n`. + * In: bin: pointer to a 32-byte array. + * Out: r: scalar to be set. + * overflow: non-zero if the scalar was bigger or equal to `n` before reduction, zero otherwise (can be NULL). + */ static void secp256k1_scalar_set_b32(secp256k1_scalar *r, const unsigned char *bin, int *overflow); +/** Set a scalar from a big endian byte array and returns 1 if it is a valid + * seckey and 0 otherwise. */ +static int secp256k1_scalar_set_b32_seckey(secp256k1_scalar *r, const unsigned char *bin); + /** Set a scalar to an unsigned integer. */ static void secp256k1_scalar_set_int(secp256k1_scalar *r, unsigned int v); @@ -103,4 +111,7 @@ static void secp256k1_scalar_split_lambda(secp256k1_scalar *r1, secp256k1_scalar /** Multiply a and b (without taking the modulus!), divide by 2**shift, and round to the nearest integer. Shift must be at least 256. */ static void secp256k1_scalar_mul_shift_var(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b, unsigned int shift); +/** If flag is true, set *r equal to *a; otherwise leave it. Constant-time. Both *r and *a must be initialized.*/ +static void secp256k1_scalar_cmov(secp256k1_scalar *r, const secp256k1_scalar *a, int flag); + #endif /* SECP256K1_SCALAR_H */ |