Files
python-nostr/nostr/event.py
2022-11-15 07:37:32 -05:00

66 lines
2.3 KiB
Python

import time
import json
from enum import IntEnum
from secp256k1 import PrivateKey, PublicKey
from hashlib import sha256
class EventKind(IntEnum):
SET_METADATA = 0
TEXT_NOTE = 1
RECOMMEND_RELAY = 2
CONTACTS = 3
ENCRYPTED_DIRECT_MESSAGE = 4
DELETE = 5
class Event():
def __init__(
self,
public_key: str,
content: str,
created_at: int=int(time.time()),
kind: int=EventKind.TEXT_NOTE,
tags: "list[list[str]]"=[],
id: str=None,
signature: str=None) -> None:
if not isinstance(content, str):
raise TypeError("Argument 'content' must be of type str")
self.id = id if not id is None else Event.compute_id(public_key, created_at, kind, tags, content)
self.public_key = public_key
self.content = content
self.created_at = created_at
self.kind = kind
self.tags = tags
self.signature = signature
@staticmethod
def serialize(public_key: str, created_at: int, kind: int, tags: "list[list[str]]", content: str) -> bytes:
data = [0, public_key, created_at, kind, tags, content]
data_str = json.dumps(data, separators=(',', ':'), ensure_ascii=False)
return data_str.encode()
@staticmethod
def compute_id(public_key: str, created_at: int, kind: int, tags: "list[list[str]]", content: str) -> str:
return sha256(Event.serialize(public_key, created_at, kind, tags, content)).hexdigest()
def sign(self, private_key_hex: str) -> None:
sk = PrivateKey(bytes.fromhex(private_key_hex))
sig = sk.schnorr_sign(bytes.fromhex(self.id), None, raw=True)
self.signature = sig.hex()
def verify(self) -> bool:
pub_key = PublicKey(bytes.fromhex("02" + self.public_key), True) # add 02 for schnorr (bip340)
event_id = Event.compute_id(self.public_key, self.created_at, self.kind, self.tags, self.content)
return pub_key.schnorr_verify(bytes.fromhex(event_id), bytes.fromhex(self.signature), None, raw=True)
def to_json_object(self) -> dict:
return {
"id": self.id,
"pubkey": self.public_key,
"created_at": self.created_at,
"kind": self.kind,
"tags": self.tags,
"content": self.content,
"sig": self.signature
}