Files
nutshell/cashu/core/legacy.py
2023-05-01 23:09:16 +02:00

52 lines
1.5 KiB
Python

import hashlib
from secp256k1 import PrivateKey, PublicKey
from ..core.settings import settings
def hash_to_point_pre_0_3_3(secret_msg):
"""
NOTE: Clients pre 0.3.3 used a different hash_to_curve
Generates x coordinate from the message hash and checks if the point lies on the curve.
If it does not, it tries computing again a new x coordinate from the hash of the coordinate.
"""
point = None
msg = secret_msg
while point is None:
_hash = hashlib.sha256(msg).hexdigest().encode("utf-8") # type: ignore
try:
# We construct compressed pub which has x coordinate encoded with even y
_hash = list(_hash[:33]) # take the 33 bytes and get a list of bytes
_hash[0] = 0x02 # set first byte to represent even y coord
_hash = bytes(_hash)
point = PublicKey(_hash, raw=True)
except:
msg = _hash
return point
def verify_pre_0_3_3(a, C, secret_msg):
Y = hash_to_point_pre_0_3_3(secret_msg.encode("utf-8"))
return C == Y.mult(a) # type: ignore
def derive_keys_backwards_compatible_insecure_pre_0_12(
master_key: str, derivation_path: str = ""
):
"""
WARNING: Broken key derivation for backwards compatibility with 0.11.
"""
return {
2
** i: PrivateKey(
hashlib.sha256((master_key + derivation_path + str(i)).encode("utf-8"))
.hexdigest()
.encode("utf-8")[:32],
raw=True,
)
for i in range(settings.max_order)
}