Cet exemple vous montre comment démarrer l’authentification avec un appareil suivi. Pour terminer la connexion, le client doit répondre correctement aux stimulations SRP (Secure Remote Password).
class CognitoIdentityProviderWrapper:
"""Encapsulates Amazon Cognito actions"""
def __init__(self, cognito_idp_client, user_pool_id, client_id, client_secret=None):
"""
:param cognito_idp_client: A Boto3 Amazon Cognito Identity Provider client.
:param user_pool_id: The ID of an existing Amazon Cognito user pool.
:param client_id: The ID of a client application registered with the user pool.
:param client_secret: The client secret, if the client has a secret.
"""
self.cognito_idp_client = cognito_idp_client
self.user_pool_id = user_pool_id
self.client_id = client_id
self.client_secret = client_secret
def sign_in_with_tracked_device(
self,
user_name,
password,
device_key,
device_group_key,
device_password,
aws_srp,
):
"""
Signs in to Amazon Cognito as a user who has a tracked device. Signing in
with a tracked device lets a user sign in without entering a new MFA code.
Signing in with a tracked device requires that the client respond to the SRP
protocol. The scenario associated with this example uses the warrant package
to help with SRP calculations.
For more information on SRP, see https://en.wikipedia.org/wiki/Secure_Remote_Password_protocol.
:param user_name: The user that is associated with the device.
:param password: The user's password.
:param device_key: The key of a tracked device.
:param device_group_key: The group key of a tracked device.
:param device_password: The password that is associated with the device.
:param aws_srp: A class that helps with SRP calculations. The scenario
associated with this example uses the warrant package.
:return: The result of the authentication. When successful, this contains an
access token for the user.
"""
try:
srp_helper = aws_srp.AWSSRP(
username=user_name,
password=device_password,
pool_id="_",
client_id=self.client_id,
client_secret=None,
client=self.cognito_idp_client,
)
response_init = self.cognito_idp_client.initiate_auth(
ClientId=self.client_id,
AuthFlow="USER_PASSWORD_AUTH",
AuthParameters={
"USERNAME": user_name,
"PASSWORD": password,
"DEVICE_KEY": device_key,
},
)
if response_init["ChallengeName"] != "DEVICE_SRP_AUTH":
raise RuntimeError(
f"Expected DEVICE_SRP_AUTH challenge but got {response_init['ChallengeName']}."
)
auth_params = srp_helper.get_auth_params()
auth_params["DEVICE_KEY"] = device_key
response_auth = self.cognito_idp_client.respond_to_auth_challenge(
ClientId=self.client_id,
ChallengeName="DEVICE_SRP_AUTH",
ChallengeResponses=auth_params,
)
if response_auth["ChallengeName"] != "DEVICE_PASSWORD_VERIFIER":
raise RuntimeError(
f"Expected DEVICE_PASSWORD_VERIFIER challenge but got "
f"{response_init['ChallengeName']}."
)
challenge_params = response_auth["ChallengeParameters"]
challenge_params["USER_ID_FOR_SRP"] = device_group_key + device_key
cr = srp_helper.process_challenge(challenge_params, {"USERNAME": user_name})
cr["USERNAME"] = user_name
cr["DEVICE_KEY"] = device_key
response_verifier = self.cognito_idp_client.respond_to_auth_challenge(
ClientId=self.client_id,
ChallengeName="DEVICE_PASSWORD_VERIFIER",
ChallengeResponses=cr,
)
auth_tokens = response_verifier["AuthenticationResult"]
except ClientError as err:
logger.error(
"Couldn't start client sign in for %s. Here's why: %s: %s",
user_name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return auth_tokens
