Аутентификация и подпись запросов (RSA)

import base64
import json
import time
import requests

from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.asymmetric import padding
from cryptography.hazmat.primitives import serialization

url = "https://api.hh-processing.com/api/v1/payment/p2p/payin"

# Идентификатор кассы (UUID)
project_id = "57aff4db-b45d-42bf-bc5f-b7a499a01782"

# Приватный RSA-ключ (PEM)
with open("private_key.pem", "rb") as key_file:
    private_key = serialization.load_pem_private_key(
        key_file.read(),
        password=None,
    )

payload = {
    "general": {
        "project_id": project_id
    }
}


def parse_json(prefix, obj, result):
    if isinstance(obj, dict):
        for key, value in obj.items():
            if isinstance(key, bool):
                key = int(key)
            new_prefix = f"{prefix}:{key}" if prefix else str(key)
            parse_json(new_prefix, value, result)
    elif isinstance(obj, list):
        for index, item in enumerate(obj):
            if isinstance(item, bool):
                item = int(item)
            new_prefix = f"{prefix}:{index}"
            parse_json(new_prefix, item, result)
    else:
        if isinstance(obj, bool):
            obj = int(obj)
        if obj is None:
            obj = ""
        result.append(f"{prefix}:{obj}")


def normalize_message(data):
    result = []
    parse_json("", data, result)
    result.sort()
    return ";".join(result)


# Публичный ключ (Base64Url)
public_key_bytes = private_key.public_key().public_bytes(
    encoding=serialization.Encoding.PEM,
    format=serialization.PublicFormat.SubjectPublicKeyInfo,
)
api_key = base64.urlsafe_b64encode(public_key_bytes).decode("utf-8")

# Метка времени Unix (секунды)
timestamp = int(time.time())

# Нормализация тела запроса
joined_result = normalize_message(payload)

# Формирование сообщения для подписи
message = "{}{}".format(
    base64.urlsafe_b64encode(joined_result.encode()).decode("utf-8"),
    str(timestamp),
).encode("utf-8")

# Подпись RSA-SHA256
signature_bytes = private_key.sign(
    message,
    padding.PKCS1v15(),
    hashes.SHA256()
)
signature_b64url = base64.urlsafe_b64encode(signature_bytes).decode("utf-8")

# Заголовки
headers = {
    "content-type": "application/json",
    "x-access-token": api_key,
    "x-access-signature": signature_b64url,
    "x-access-merchant-id": project_id,
    "x-access-timestamp": str(timestamp),
}

# Тело запроса (JSON)
dumped = json.dumps(payload, separators=(",", ":")) if payload else "{}"

response = requests.post(url, headers=headers, data=dumped)
print(response.status_code)