def ec_pubkey_tweak_mul(ctx, pubkey, tweak):
'''Tweak a public key by multiplying it by a tweak value.
Args:
ctx (secp256k1_context*): pointer to a context object
initialized for validation (cannot be
NULL)
pubkey (secp2561_pubkey*): pointer to a public key object
tweak (bytes): pointer to a 32-byte tweak
Returns:
(int, secp256k1_pubkey*): (0 if the tweak was out of range
(chance of around 1 in 2^128 for
uniformly random 32-byte arrays, or
equal to zero. 1 otherwise,
pointer to a public key object)
'''
# Validate context
utils.validate_context(ctx)
# Validate public key
utils.validate_public_key(pubkey)
# Validate tweak
utils.validate_tweak_ser(tweak)
return (lib.secp256k1_ec_pubkey_tweak_mul(ctx, pubkey, tweak), pubkey)
def ec_pubkey_tweak_add(ctx, pubkey, tweak):
''' Tweak a public key by adding tweak times the generator to it.
Args:
ctx (secp256k1_context*): pointer to a context object (cannot be
NULL)
pubkey (secp256k1_pubkey*): pointer to a public key object
tweak (bytes): pointer to a 32-byte tweak
Returns:
(int, secp256k1_pubkey*): (0 if the tweak was out of range
(change of around 1 in 2^128 for
uniformly random 32-byte arrays),
or if the resulting public key
would be invalid (only when the
tweak is the complement of the
corresponding private key). 1
otherwise,
a pointer to a secp256k1_pubkey
containing tweaked public key)
'''
# Validate context
utils.validate_context(ctx)
# Validate public key
utils.validate_public_key(pubkey)
# Validate tweak
utils.validate_tweak_ser(tweak)
return (lib.secp256k1_ec_pubkey_tweak_add(ctx, pubkey, tweak), pubkey)
def ec_privkey_tweak_mul(ctx, seckey, tweak):
'''Tweak a private key by multiplying it by a tweak.
Args:
ctx (secp256k1_context*): pointer to a context object (cannot be
NULL)
seckey (bytes): pointer to a 32-byte private key
tweak (bytes): pointer to a 32-byte tweak
Returns:
(int, seckey): (0 if the tweak was out of range
(chance of around 1 in 2^128 for
uniformly random 32-byte arrays, or
equal to zero. 1 otherwise,
pointer to a 32-byte private key)
'''
# Validate context
utils.validate_context(ctx)
# Validate secret key
utils.validate_secret_key_ser(seckey)
# Validate tweak
utils.validate_tweak_ser(tweak)
return (lib.secp256k1_ec_privkey_tweak_mul(ctx, seckey, tweak), seckey)