AWS SDK Version 3 for .NET
API Reference

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Container for the parameters to the InitiateAuth operation. Initiates sign-in for a user in the Amazon Cognito user directory. You can't sign in a user with a federated IdP with InitiateAuth. For more information, see Adding user pool sign-in through a third party.

Amazon Cognito doesn't evaluate Identity and Access Management (IAM) policies in requests for this API operation. For this operation, you can't use IAM credentials to authorize requests, and you can't grant IAM permissions in policies. For more information about authorization models in Amazon Cognito, see Using the Amazon Cognito user pools API and user pool endpoints.

This action might generate an SMS text message. Starting June 1, 2021, US telecom carriers require you to register an origination phone number before you can send SMS messages to US phone numbers. If you use SMS text messages in Amazon Cognito, you must register a phone number with Amazon Pinpoint. Amazon Cognito uses the registered number automatically. Otherwise, Amazon Cognito users who must receive SMS messages might not be able to sign up, activate their accounts, or sign in.

If you have never used SMS text messages with Amazon Cognito or any other Amazon Web Service, Amazon Simple Notification Service might place your account in the SMS sandbox. In sandbox mode, you can send messages only to verified phone numbers. After you test your app while in the sandbox environment, you can move out of the sandbox and into production. For more information, see SMS message settings for Amazon Cognito user pools in the Amazon Cognito Developer Guide.

Inheritance Hierarchy

System.Object
  Amazon.Runtime.AmazonWebServiceRequest
    Amazon.CognitoIdentityProvider.AmazonCognitoIdentityProviderRequest
      Amazon.CognitoIdentityProvider.Model.InitiateAuthRequest

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

Syntax

C# 
public class InitiateAuthRequest : AmazonCognitoIdentityProviderRequest
         IAmazonWebServiceRequest

The InitiateAuthRequest type exposes the following members

Constructors

NameDescription
Public Method InitiateAuthRequest()

Properties

NameTypeDescription
Public Property AnalyticsMetadata Amazon.CognitoIdentityProvider.Model.AnalyticsMetadataType

Gets and sets the property AnalyticsMetadata.

The Amazon Pinpoint analytics metadata that contributes to your metrics for InitiateAuth calls.

Public Property AuthFlow Amazon.CognitoIdentityProvider.AuthFlowType

Gets and sets the property AuthFlow.

The authentication flow for this call to run. The API action will depend on this value. For example:

  • REFRESH_TOKEN_AUTH takes in a valid refresh token and returns new tokens.

  • USER_SRP_AUTH takes in USERNAME and SRP_A and returns the SRP variables to be used for next challenge execution.

  • USER_PASSWORD_AUTH takes in USERNAME and PASSWORD and returns the next challenge or tokens.

Valid values include:

  • USER_SRP_AUTH: Authentication flow for the Secure Remote Password (SRP) protocol.

  • REFRESH_TOKEN_AUTH/REFRESH_TOKEN: Authentication flow for refreshing the access token and ID token by supplying a valid refresh token.

  • CUSTOM_AUTH: Custom authentication flow.

  • USER_PASSWORD_AUTH: Non-SRP authentication flow; user name and password are passed directly. If a user migration Lambda trigger is set, this flow will invoke the user migration Lambda if it doesn't find the user name in the user pool.

ADMIN_NO_SRP_AUTH isn't a valid value.

Public Property AuthParameters System.Collections.Generic.Dictionary<System.String, System.String>

Gets and sets the property AuthParameters.

The authentication parameters. These are inputs corresponding to the AuthFlow that you're invoking. The required values depend on the value of AuthFlow:

  • For USER_SRP_AUTH: USERNAME (required), SRP_A (required), SECRET_HASH (required if the app client is configured with a client secret), DEVICE_KEY.

  • For USER_PASSWORD_AUTH: USERNAME (required), PASSWORD (required), SECRET_HASH (required if the app client is configured with a client secret), DEVICE_KEY.

  • For REFRESH_TOKEN_AUTH/REFRESH_TOKEN: REFRESH_TOKEN (required), SECRET_HASH (required if the app client is configured with a client secret), DEVICE_KEY.

  • For CUSTOM_AUTH: USERNAME (required), SECRET_HASH (if app client is configured with client secret), DEVICE_KEY. To start the authentication flow with password verification, include ChallengeName: SRP_A and SRP_A: (The SRP_A Value).

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.

Public Property ClientId System.String

Gets and sets the property ClientId.

The app client ID.

Public Property ClientMetadata System.Collections.Generic.Dictionary<System.String, System.String>

Gets and sets the property ClientMetadata.

A map of custom key-value pairs that you can provide as input for certain custom workflows that this action triggers.

You create custom workflows by assigning Lambda functions to user pool triggers. When you use the InitiateAuth API action, Amazon Cognito invokes the Lambda functions that are specified for various triggers. The ClientMetadata value is passed as input to the functions for only the following triggers:

  • Pre signup

  • Pre authentication

  • User migration

When Amazon Cognito invokes the functions for these triggers, it passes a JSON payload, which the function receives as input. This payload contains a validationData attribute, which provides the data that you assigned to the ClientMetadata parameter in your InitiateAuth request. In your function code in Lambda, you can process the validationData value to enhance your workflow for your specific needs.

When you use the InitiateAuth API action, Amazon Cognito also invokes the functions for the following triggers, but it doesn't provide the ClientMetadata value as input:

  • Post authentication

  • Custom message

  • Pre token generation

  • Create auth challenge

  • Define auth challenge

For more information, see Customizing user pool Workflows with Lambda Triggers in the Amazon Cognito Developer Guide.

When you use the ClientMetadata parameter, remember that Amazon Cognito won't do the following:

  • Store the ClientMetadata value. This data is available only to Lambda triggers that are assigned to a user pool to support custom workflows. If your user pool configuration doesn't include triggers, the ClientMetadata parameter serves no purpose.

  • Validate the ClientMetadata value.

  • Encrypt the ClientMetadata value. Don't use Amazon Cognito to provide sensitive information.

Public Property UserContextData Amazon.CognitoIdentityProvider.Model.UserContextDataType

Gets and sets the property UserContextData.

Contextual data about your user session, such as the device fingerprint, IP address, or location. Amazon Cognito advanced security evaluates the risk of an authentication event based on the context that your app generates and passes to Amazon Cognito when it makes API requests.

Examples

The following example signs in the user mytestuser with analytics data, client metadata, and user context data for advanced security.

Example username and password sign-in for a user who has TOTP MFA


var client = new AmazonCognitoIdentityProviderClient();
var response = client.InitiateAuth(new InitiateAuthRequest 
{
    AnalyticsMetadata = new AnalyticsMetadataType { AnalyticsEndpointId = "d70b2ba36a8c4dc5a04a0451a31a1e12" },
    AuthFlow = "USER_PASSWORD_AUTH",
    AuthParameters = new Dictionary<string, string> {
        { "PASSWORD", "This-is-my-test-99!" },
        { "SECRET_HASH", "oT5ZkS8ctnrhYeeGsGTvOzPhoc/Jd1cO5fueBWFVmp8=" },
        { "USERNAME", "mytestuser" }
    },
    ClientId = "1example23456789",
    ClientMetadata = new Dictionary<string, string> {
        { "MyTestKey", "MyTestValue" }
    },
    UserContextData = new UserContextDataType {
        EncodedData = "AmazonCognitoAdvancedSecurityData_object",
        IpAddress = "192.0.2.1"
    }
});

string challengeName = response.ChallengeName;
Dictionary<string, string> challengeParameters = response.ChallengeParameters;
string session = response.Session;

Version Information

.NET Core App:
Supported in: 3.1

.NET Standard:
Supported in: 2.0

.NET Framework:
Supported in: 4.5, 4.0, 3.5