Files
saladeaula.digital/http-api/auth.py

72 lines
2.0 KiB
Python

from dataclasses import dataclass
import boto3
from aws_lambda_powertools import Logger, Tracer
from aws_lambda_powertools.utilities.data_classes import event_source
from aws_lambda_powertools.utilities.data_classes.api_gateway_authorizer_event import (
APIGatewayAuthorizerEventV2,
APIGatewayAuthorizerResponseV2,
)
from aws_lambda_powertools.utilities.typing import LambdaContext
from botocore.endpoint_provider import Enum
from cognito import get_user
APIKEY_PREFIX = 'edxg'
tracer = Tracer()
logger = Logger(__name__)
idp_client = boto3.client('cognito-idp')
@tracer.capture_lambda_handler
@logger.inject_lambda_context
@event_source(data_class=APIGatewayAuthorizerEventV2)
def lambda_handler(event: APIGatewayAuthorizerEventV2, context: LambdaContext):
bearer = _parse_bearer_token(event.headers.get('authorization', ''))
if not bearer:
return APIGatewayAuthorizerResponseV2(authorize=False).asdict()
if bearer.auth_type == TokenType.USER_TOKEN:
user = get_user(bearer.token, idp_client=idp_client)
if user:
return APIGatewayAuthorizerResponseV2(
authorize=True,
context=dict(user=user),
).asdict()
return APIGatewayAuthorizerResponseV2(authorize=False).asdict()
class TokenType(str, Enum):
API_KEY = 'API_KEY'
USER_TOKEN = 'USER_TOKEN'
@dataclass
class BearerToken:
auth_type: TokenType
token: str
def _parse_bearer_token(
s: str,
*,
apikey_prefix: str = APIKEY_PREFIX,
) -> BearerToken | None:
"""Parses and identifies a bearer token as either an API key or a user token."""
try:
_, bearer_token = s.split(' ')
if bearer_token.startswith(f'{apikey_prefix}-'):
return BearerToken(
TokenType.API_KEY,
bearer_token.removeprefix(f'{apikey_prefix}-'),
)
except ValueError:
return None
else:
return BearerToken(TokenType.USER_TOKEN, bearer_token)