lbry-sdk/lbry/lbrynet/extras/daemon/comment_client.py

import logging
import time
import hashlib
import binascii

import aiohttp
import ecdsa
from torba.client.hash import sha256
from lbrynet.wallet.transaction import Output

log = logging.getLogger(__name__)


def get_encoded_signature(signature):
    signature = signature.encode() if type(signature) is str else signature
    r = int(signature[:int(len(signature) / 2)], 16)
    s = int(signature[int(len(signature) / 2):], 16)
    return ecdsa.util.sigencode_der(r, s, len(signature) * 4)


def is_comment_signed_by_channel(comment: dict, channel: Output):
    try:
        pieces = [
            comment['signing_ts'].encode(),
            channel.claim_hash,
            comment['comment'].encode()
        ]
        return Output.is_signature_valid(
            get_encoded_signature(comment['signature']),
            sha256(b''.join(pieces)),
            channel.claim.channel.public_key_bytes
        )
    except KeyError:
        pass
    return False


def sign_comment(comment: dict, channel: Output):
    timestamp = str(int(time.time())).encode()
    pieces = [timestamp, channel.claim_hash, comment['comment'].encode()]
    digest = sha256(b''.join(pieces))
    signature = channel.private_key.sign_digest_deterministic(digest, hashfunc=hashlib.sha256)
    comment['signature'] = binascii.hexlify(signature).decode()
    comment['signing_ts'] = timestamp.decode()


async def jsonrpc_post(url: str, method: str, **params) -> any:
    json_body = {'jsonrpc': '2.0', 'id': None, 'method': method, 'params': params}
    headers = {'Content-Type': 'application/json'}
    async with aiohttp.request('POST', url, json=json_body, headers=headers) as response:
        try:
            result = await response.json()
            return result['result'] if 'result' in result else result
        except aiohttp.client.ContentTypeError as cte:
            log.exception('Unable to decode respose from server: %s', cte)
            return await response.text()