Request Syntax Request Parameters Response Syntax Response Elements Errors Examples See Also

InitiateAuth

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.

Note

Amazon Cognito doesn't evaluate AWS 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.

Note

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 AWS 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.

Request Syntax


{
   "AnalyticsMetadata": { 
      "AnalyticsEndpointId": "string"
   },
   "AuthFlow": "string",
   "AuthParameters": { 
      "string" : "string" 
   },
   "ClientId": "string",
   "ClientMetadata": { 
      "string" : "string" 
   },
   "UserContextData": { 
      "EncodedData": "string",
      "IpAddress": "string"
   }
}

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

The request accepts the following data in JSON format.

AnalyticsMetadata

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

Type: AnalyticsMetadataType object

Required: No

AuthFlow

The authentication flow that you want to initiate. The AuthParameters that you must submit are linked to the flow that you submit. For example:

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.

Valid values include the following:

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 AdminInitiateAuth and isn't valid for InitiateAuth. ADMIN_NO_SRP_AUTH is a legacy server-side username-password flow and isn't valid for InitiateAuth.

Type: String

Required: Yes

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.

Type: String to string map

Key Length Constraints: Minimum length of 0. Maximum length of 131072.

Value Length Constraints: Minimum length of 0. Maximum length of 131072.

Required: No

ClientId

The app client ID.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 128.

Pattern: [\w+]+

Required: Yes

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 AWS 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.

Note

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 AWS 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.

Type: String to string map

Key Length Constraints: Minimum length of 0. Maximum length of 131072.

Value Length Constraints: Minimum length of 0. Maximum length of 131072.

Required: No

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.

Type: UserContextDataType object

Required: No

Response Syntax


{
   "AuthenticationResult": { 
      "AccessToken": "string",
      "ExpiresIn": number,
      "IdToken": "string",
      "NewDeviceMetadata": { 
         "DeviceGroupKey": "string",
         "DeviceKey": "string"
      },
      "RefreshToken": "string",
      "TokenType": "string"
   },
   "ChallengeName": "string",
   "ChallengeParameters": { 
      "string" : "string" 
   },
   "Session": "string"
}

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.

AuthenticationResult

The result of the authentication response. This result is only returned if the caller doesn't need to pass another challenge. If the caller does need to pass another challenge before it gets tokens, ChallengeName, ChallengeParameters, and Session are returned.

Type: AuthenticationResultType object

ChallengeName

The name of the challenge that you're responding to with this call. This name is returned in the InitiateAuth response if you must pass another challenge.

Valid values include the following:

Note

All of the following challenges require USERNAME and SECRET_HASH (if applicable) in the parameters.

SMS_MFA: Next challenge is to supply an SMS_MFA_CODEthat your user pool delivered in an SMS message.
EMAIL_OTP: Next challenge is to supply an EMAIL_OTP_CODE that your user pool delivered in an email message.
PASSWORD_VERIFIER: Next challenge is to supply PASSWORD_CLAIM_SIGNATURE, PASSWORD_CLAIM_SECRET_BLOCK, and TIMESTAMP after the client-side SRP calculations.
CUSTOM_CHALLENGE: This is returned if your custom authentication flow determines that the user should pass another challenge before tokens are issued.
DEVICE_SRP_AUTH: If device tracking was activated on your user pool and the previous challenges were passed, this challenge is returned so that Amazon Cognito can start tracking this device.
DEVICE_PASSWORD_VERIFIER: Similar to PASSWORD_VERIFIER, but for devices only.
NEW_PASSWORD_REQUIRED: For users who are required to change their passwords after successful first login.

Respond to this challenge with NEW_PASSWORD and any required attributes that Amazon Cognito returned in the requiredAttributes parameter. You can also set values for attributes that aren't required by your user pool and that your app client can write. For more information, see RespondToAuthChallenge.

Note
In a NEW_PASSWORD_REQUIRED challenge response, you can't modify a required attribute that already has a value. In RespondToAuthChallenge, set a value for any keys that Amazon Cognito returned in the requiredAttributes parameter, then use the UpdateUserAttributes API operation to modify the value of any additional attributes.
MFA_SETUP: For users who are required to setup an MFA factor before they can sign in. The MFA types activated for the user pool will be listed in the challenge parameters MFAS_CAN_SETUP value.

To set up software token MFA, use the session returned here from InitiateAuth as an input to AssociateSoftwareToken. Use the session returned by VerifySoftwareToken as an input to RespondToAuthChallenge with challenge name MFA_SETUP to complete sign-in. To set up SMS MFA, an administrator should help the user to add a phone number to their account, and then the user should call InitiateAuth again to restart sign-in.

Type: String

ChallengeParameters

The challenge parameters. These are returned in the InitiateAuth response if you must pass another challenge. The responses in this parameter should be used to compute inputs to the next call (RespondToAuthChallenge).

All challenges require USERNAME and SECRET_HASH (if applicable).

Type: String to string map

Key Length Constraints: Minimum length of 0. Maximum length of 131072.

Value Length Constraints: Minimum length of 0. Maximum length of 131072.

Session

The session that should pass both ways in challenge-response calls to the service. If the caller must pass another challenge, they return a session with other challenge parameters. This session should be passed as it is to the next RespondToAuthChallenge API call.

Type: String

Length Constraints: Minimum length of 20. Maximum length of 2048.

Errors

For information about the errors that are common to all actions, see Common Errors.

ForbiddenException

This exception is thrown when AWS WAF doesn't allow your request based on a web ACL that's associated with your user pool.

HTTP Status Code: 400

InternalErrorException

This exception is thrown when Amazon Cognito encounters an internal error.

HTTP Status Code: 500

InvalidEmailRoleAccessPolicyException

This exception is thrown when Amazon Cognito isn't allowed to use your email identity. HTTP status code: 400.

HTTP Status Code: 400

InvalidLambdaResponseException

This exception is thrown when Amazon Cognito encounters an invalid AWS Lambda response.

HTTP Status Code: 400

InvalidParameterException

This exception is thrown when the Amazon Cognito service encounters an invalid parameter.

HTTP Status Code: 400

InvalidSmsRoleAccessPolicyException

This exception is returned when the role provided for SMS configuration doesn't have permission to publish using Amazon SNS.

HTTP Status Code: 400

InvalidSmsRoleTrustRelationshipException

This exception is thrown when the trust relationship is not valid for the role provided for SMS configuration. This can happen if you don't trust cognito-idp.amazonaws.com or the external ID provided in the role does not match what is provided in the SMS configuration for the user pool.

HTTP Status Code: 400

InvalidUserPoolConfigurationException

This exception is thrown when the user pool configuration is not valid.

HTTP Status Code: 400

NotAuthorizedException

This exception is thrown when a user isn't authorized.

HTTP Status Code: 400

PasswordResetRequiredException

This exception is thrown when a password reset is required.

HTTP Status Code: 400

ResourceNotFoundException

This exception is thrown when the Amazon Cognito service can't find the requested resource.

HTTP Status Code: 400

TooManyRequestsException

This exception is thrown when the user has made too many requests for a given operation.

HTTP Status Code: 400

UnexpectedLambdaException

This exception is thrown when Amazon Cognito encounters an unexpected exception with AWS Lambda.

HTTP Status Code: 400

UserLambdaValidationException

This exception is thrown when the Amazon Cognito service encounters a user validation exception with the AWS Lambda service.

HTTP Status Code: 400

UserNotConfirmedException

This exception is thrown when a user isn't confirmed successfully.

HTTP Status Code: 400

UserNotFoundException

This exception is thrown when a user isn't found.

HTTP Status Code: 400

Examples

Example

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

Sample Request


POST / HTTP/1.1
Content-Type: application/x-amz-json-1.1
X-Amz-Target: AWSCognitoIdentityProviderService.InitiateAuth
User-Agent: <UserAgentString>
Accept: */*
Host: cognito-idp.us-east-1.amazonaws.com
Accept-Encoding: gzip, deflate, br
Connection: keep-alive
Content-Length: <PayloadSizeBytes>
{
    "AuthFlow": "USER_PASSWORD_AUTH",
    "ClientId": "1example23456789",
    "AuthParameters": {
        "USERNAME": "mytestuser",
        "PASSWORD": "This-is-my-test-99!",
        "SECRET_HASH": "oT5ZkS8ctnrhYeeGsGTvOzPhoc/Jd1cO5fueBWFVmp8="
    },
    "AnalyticsMetadata": {
        "AnalyticsEndpointId": "d70b2ba36a8c4dc5a04a0451a31a1e12"
    },
    "UserContextData": {
        "EncodedData": "AmazonCognitoAdvancedSecurityData_object",
        "IpAddress": "192.0.2.1"
    },
    "ClientMetadata": {
        "MyTestKey": "MyTestValue"
    }
}

Sample Response


HTTP/1.1 200 OK
Date: Tue, 13 Jun 2023 20:00:59 GMT
Content-Type: application/x-amz-json-1.0
Content-Length: <PayloadSizeBytes>
x-amzn-requestid: a1b2c3d4-e5f6-a1b2-c3d4-EXAMPLE11111
Connection: keep-alive

{
    "ChallengeName": "SOFTWARE_TOKEN_MFA",
    "ChallengeParameters": {
        "USER_ID_FOR_SRP": "mytestuser",
        "FRIENDLY_DEVICE_NAME": "mytestauthenticator"
    },
    "Session": "AYABeC1-y8qooiuysEv0uM4wAqQAHQABAAdTZXJ2aWNlABBDb2duaXRvVXNlclBvb2xzAAEAB2F3cy1rbXMAS2Fybjphd3M6a21zOnVzLXd..."
}

Example

The following example exchanges a refresh token for access and ID tokens.

Sample Request


POST / HTTP/1.1
Content-Type: application/x-amz-json-1.1
X-Amz-Target: AWSCognitoIdentityProviderService.InitiateAuth
User-Agent: <UserAgentString>
Accept: */*
Host: cognito-idp.us-east-1.amazonaws.com
Accept-Encoding: gzip, deflate, br
Connection: keep-alive
Content-Length: 1964                    
                    
{
    "AuthFlow": "REFRESH_TOKEN",
    "ClientId": "1example23456789",
    "AuthParameters": {
        "REFRESH_TOKEN": "eyJ123abcEXAMPLE",
        "SECRET_HASH": "7P85/EXAMPLE"
    }
}

Sample Response


HTTP/1.1 200 OK
Date: Tue, 13 Jun 2023 20:00:59 GMT
Content-Type: application/x-amz-json-1.0
Content-Length: <PayloadSizeBytes>
x-amzn-requestid: a1b2c3d4-e5f6-a1b2-c3d4-EXAMPLE11111
Connection: keep-alive

{
    "AuthenticationResult": {
        "AccessToken": "eyJra456defEXAMPLE",
        "ExpiresIn": 3600,
        "IdToken": "eyJra789ghiEXAMPLE",
        "TokenType": "Bearer"
    },
    "ChallengeParameters": {}
}