Initiate Auth

cognitoidentityprovider_initiate_auth

R Documentation

Initiates sign-in for a user in the Amazon Cognito user directory

Description

Initiates sign-in for a user in the Amazon Cognito user directory. You can't sign in a user with a federated IdP with initiate_auth. 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 Services 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.

Usage

cognitoidentityprovider_initiate_auth(AuthFlow, AuthParameters,
  ClientMetadata, ClientId, AnalyticsMetadata, UserContextData, Session)

Arguments

AuthFlow

[required] The authentication flow that you want to initiate. Each AuthFlow has linked AuthParameters that you must submit. The following are some example flows and their parameters.

• USER_AUTH: Request a preferred authentication type or review available authentication types. From the offered authentication types, select one in a challenge response and then authenticate with that method in an additional challenge response.

• REFRESH_TOKEN_AUTH: Receive new ID and access tokens when you pass a REFRESH_TOKEN parameter with a valid refresh token as the value.

• USER_SRP_AUTH: Receive secure remote password (SRP) variables for the next challenge, PASSWORD_VERIFIER, when you pass USERNAME and SRP_A parameters.

• USER_PASSWORD_AUTH: Receive new tokens or the next challenge, for example SOFTWARE_TOKEN_MFA, when you pass USERNAME and PASSWORD parameters.

All flows

USER_AUTH

The entry point for sign-in with passwords, one-time passwords, and WebAuthN authenticators.

USER_SRP_AUTH

Username-password authentication with the Secure Remote Password (SRP) protocol. For more information, see Use SRP password verification in custom authentication flow.

REFRESH_TOKEN_AUTH and REFRESH_TOKEN

Provide a valid refresh token and receive new ID and access tokens. For more information, see Using the refresh token.

CUSTOM_AUTH

Custom authentication with Lambda triggers. For more information, see Custom authentication challenge Lambda triggers.

USER_PASSWORD_AUTH

Username-password authentication with the password sent directly in the request. For more information, see Admin authentication flow.

ADMIN_USER_PASSWORD_AUTH is a flow type of admin_initiate_auth and isn't valid for InitiateAuth. ADMIN_NO_SRP_AUTH is a legacy server-side username-password flow and isn't valid for InitiateAuth.

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_AUTH: USERNAME (required), PREFERRED_CHALLENGE. If you don't provide a value for PREFERRED_CHALLENGE, Amazon Cognito responds with the AvailableChallenges parameter that specifies the available sign-in methods.

• 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.

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

• Custom email sender

• Custom SMS sender

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

When you use the ClientMetadata parameter, note 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 send sensitive information in this parameter.

ClientId

[required] The app client ID.

AnalyticsMetadata

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

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.

For more information, see Collecting data for threat protection in applications.

Session

The optional session ID from a confirm_sign_up API request. You can sign in a user directly from the sign-up process with the USER_AUTH authentication flow.

Value

A list with the following syntax:

list(
  ChallengeName = "SMS_MFA"|"EMAIL_OTP"|"SOFTWARE_TOKEN_MFA"|"SELECT_MFA_TYPE"|"MFA_SETUP"|"PASSWORD_VERIFIER"|"CUSTOM_CHALLENGE"|"SELECT_CHALLENGE"|"DEVICE_SRP_AUTH"|"DEVICE_PASSWORD_VERIFIER"|"ADMIN_NO_SRP_AUTH"|"NEW_PASSWORD_REQUIRED"|"SMS_OTP"|"PASSWORD"|"WEB_AUTHN"|"PASSWORD_SRP",
  Session = "string",
  ChallengeParameters = list(
    "string"
  ),
  AuthenticationResult = list(
    AccessToken = "string",
    ExpiresIn = 123,
    TokenType = "string",
    RefreshToken = "string",
    IdToken = "string",
    NewDeviceMetadata = list(
      DeviceKey = "string",
      DeviceGroupKey = "string"
    )
  ),
  AvailableChallenges = list(
    "SMS_MFA"|"EMAIL_OTP"|"SOFTWARE_TOKEN_MFA"|"SELECT_MFA_TYPE"|"MFA_SETUP"|"PASSWORD_VERIFIER"|"CUSTOM_CHALLENGE"|"SELECT_CHALLENGE"|"DEVICE_SRP_AUTH"|"DEVICE_PASSWORD_VERIFIER"|"ADMIN_NO_SRP_AUTH"|"NEW_PASSWORD_REQUIRED"|"SMS_OTP"|"PASSWORD"|"WEB_AUTHN"|"PASSWORD_SRP"
  )
)

Request syntax

svc$initiate_auth(
  AuthFlow = "USER_SRP_AUTH"|"REFRESH_TOKEN_AUTH"|"REFRESH_TOKEN"|"CUSTOM_AUTH"|"ADMIN_NO_SRP_AUTH"|"USER_PASSWORD_AUTH"|"ADMIN_USER_PASSWORD_AUTH"|"USER_AUTH",
  AuthParameters = list(
    "string"
  ),
  ClientMetadata = list(
    "string"
  ),
  ClientId = "string",
  AnalyticsMetadata = list(
    AnalyticsEndpointId = "string"
  ),
  UserContextData = list(
    IpAddress = "string",
    EncodedData = "string"
  ),
  Session = "string"
)