AWS SDK Version 3 for .NET
API Reference

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The responses to the challenge that you received in the previous request. Each challenge has its own required response parameters. The following examples are partial JSON request bodies that highlight challenge-response parameters.

You must provide a SECRET_HASH parameter in all challenge responses to an app client that has a client secret. Include a DEVICE_KEY for device authentication.

SELECT_CHALLENGE

"ChallengeName": "SELECT_CHALLENGE", "ChallengeResponses": { "USERNAME": "[username]", "ANSWER": "[Challenge name]"}

Available challenges are PASSWORD, PASSWORD_SRP, EMAIL_OTP, SMS_OTP, and WEB_AUTHN.

Complete authentication in the SELECT_CHALLENGE response for PASSWORD, PASSWORD_SRP, and WEB_AUTHN:

  • "ChallengeName": "SELECT_CHALLENGE", "ChallengeResponses": { "ANSWER": "WEB_AUTHN", "USERNAME": "[username]", "CREDENTIAL": "[AuthenticationResponseJSON]"}

    See AuthenticationResponseJSON.

  • "ChallengeName": "SELECT_CHALLENGE", "ChallengeResponses": { "ANSWER": "PASSWORD", "USERNAME": "[username]", "PASSWORD": "[password]"}

  • "ChallengeName": "SELECT_CHALLENGE", "ChallengeResponses": { "ANSWER": "PASSWORD_SRP", "USERNAME": "[username]", "SRP_A": "[SRP_A]"}

For SMS_OTP and EMAIL_OTP, respond with the username and answer. Your user pool will send a code for the user to submit in the next challenge response.

  • "ChallengeName": "SELECT_CHALLENGE", "ChallengeResponses": { "ANSWER": "SMS_OTP", "USERNAME": "[username]"}

  • "ChallengeName": "SELECT_CHALLENGE", "ChallengeResponses": { "ANSWER": "EMAIL_OTP", "USERNAME": "[username]"}

SMS_OTP

"ChallengeName": "SMS_OTP", "ChallengeResponses": {"SMS_OTP_CODE": "[code]", "USERNAME": "[username]"}

EMAIL_OTP

"ChallengeName": "EMAIL_OTP", "ChallengeResponses": {"EMAIL_OTP_CODE": "[code]", "USERNAME": "[username]"}

SMS_MFA

"ChallengeName": "SMS_MFA", "ChallengeResponses": {"SMS_MFA_CODE": "[code]", "USERNAME": "[username]"}

PASSWORD_VERIFIER

This challenge response is part of the SRP flow. Amazon Cognito requires that your application respond to this challenge within a few seconds. When the response time exceeds this period, your user pool returns a NotAuthorizedException error.

"ChallengeName": "PASSWORD_VERIFIER", "ChallengeResponses": {"PASSWORD_CLAIM_SIGNATURE": "[claim_signature]", "PASSWORD_CLAIM_SECRET_BLOCK": "[secret_block]", "TIMESTAMP": [timestamp], "USERNAME": "[username]"}

Add "DEVICE_KEY" when you sign in with a remembered device.

CUSTOM_CHALLENGE

"ChallengeName": "CUSTOM_CHALLENGE", "ChallengeResponses": {"USERNAME": "[username]", "ANSWER": "[challenge_answer]"}

Add "DEVICE_KEY" when you sign in with a remembered device.

NEW_PASSWORD_REQUIRED

"ChallengeName": "NEW_PASSWORD_REQUIRED", "ChallengeResponses": {"NEW_PASSWORD": "[new_password]", "USERNAME": "[username]"}

To set any required attributes that InitiateAuth returned in an requiredAttributes parameter, add "userAttributes.[attribute_name]": "[attribute_value]". This parameter can also set values for writable attributes that aren't required by your user pool.

In a NEW_PASSWORD_REQUIRED challenge response, you can't modify a required attribute that already has a value. In AdminRespondToAuthChallenge or RespondToAuthChallenge, set a value for any keys that Amazon Cognito returned in the requiredAttributes parameter, then use the AdminUpdateUserAttributes or UpdateUserAttributes API operation to modify the value of any additional attributes.

SOFTWARE_TOKEN_MFA

"ChallengeName": "SOFTWARE_TOKEN_MFA", "ChallengeResponses": {"USERNAME": "[username]", "SOFTWARE_TOKEN_MFA_CODE": [authenticator_code]}

DEVICE_SRP_AUTH

"ChallengeName": "DEVICE_SRP_AUTH", "ChallengeResponses": {"USERNAME": "[username]", "DEVICE_KEY": "[device_key]", "SRP_A": "[srp_a]"}

DEVICE_PASSWORD_VERIFIER

"ChallengeName": "DEVICE_PASSWORD_VERIFIER", "ChallengeResponses": {"DEVICE_KEY": "[device_key]", "PASSWORD_CLAIM_SIGNATURE": "[claim_signature]", "PASSWORD_CLAIM_SECRET_BLOCK": "[secret_block]", "TIMESTAMP": [timestamp], "USERNAME": "[username]"}

MFA_SETUP

"ChallengeName": "MFA_SETUP", "ChallengeResponses": {"USERNAME": "[username]"}, "SESSION": "[Session ID from VerifySoftwareToken]"

SELECT_MFA_TYPE

"ChallengeName": "SELECT_MFA_TYPE", "ChallengeResponses": {"USERNAME": "[username]", "ANSWER": "[SMS_MFA or SOFTWARE_TOKEN_MFA]"}

For more information about SECRET_HASH, see Computing secret hash values. For information about DEVICE_KEY, see Working with user devices in your user pool.

Inheritance Hierarchy

System.Object
  Amazon.CognitoIdentityProvider.Model.ChallengeResponseType

Namespace: Amazon.CognitoIdentityProvider.Model
Assembly: AWSSDK.CognitoIdentityProvider.dll
Version: 3.x.y.z

Syntax

C#
public class ChallengeResponseType

The ChallengeResponseType type exposes the following members

Constructors

NameDescription
Public Method ChallengeResponseType()

Properties

NameTypeDescription
Public Property ChallengeName Amazon.CognitoIdentityProvider.ChallengeName

Gets and sets the property ChallengeName.

The type of challenge that your previous authentication request returned in the parameter ChallengeName, for example SMS_MFA.

Public Property ChallengeResponse Amazon.CognitoIdentityProvider.ChallengeResponse

Gets and sets the property ChallengeResponse.

The set of key-value pairs that provides a response to the requested challenge.

Version Information

.NET:
Supported in: 8.0 and newer, Core 3.1

.NET Standard:
Supported in: 2.0

.NET Framework:
Supported in: 4.5 and newer, 3.5