Use ConfirmDevice with an AWS SDK or CLI

    /// <summary>
    /// Initiates and confirms tracking of the device.
    /// </summary>
    /// <param name="accessToken">The user's access token.</param>
    /// <param name="deviceKey">The key of the device from Amazon Cognito.</param>
    /// <param name="deviceName">The device name.</param>
    /// <returns></returns>
    public async Task<bool> ConfirmDeviceAsync(string accessToken, string deviceKey, string deviceName)
    {
        var request = new ConfirmDeviceRequest
        {
            AccessToken = accessToken,
            DeviceKey = deviceKey,
            DeviceName = deviceName
        };

        var response = await _cognitoService.ConfirmDeviceAsync(request);
        return response.UserConfirmationNecessary;
    }

To confirm a user device

The following confirm-device example adds a new remembered device for the current user.

aws cognito-idp confirm-device \
   --access-token eyJra456defEXAMPLE \
   --device-key us-west-2_a1b2c3d4-5678-90ab-cdef-EXAMPLE11111 \
   --device-secret-verifier-config PasswordVerifier=TXlWZXJpZmllclN0cmluZw,Salt=TXlTUlBTYWx0

Output:

{
     "UserConfirmationNecessary": false
}

For more information, see Working with user devices in your user pool in the Amazon Cognito Developer Guide.

const confirmDevice = ({ deviceKey, accessToken, passwordVerifier, salt }) => {
  const client = new CognitoIdentityProviderClient({});

  const command = new ConfirmDeviceCommand({
    DeviceKey: deviceKey,
    AccessToken: accessToken,
    DeviceSecretVerifierConfig: {
      PasswordVerifier: passwordVerifier,
      Salt: salt,
    },
  });

  return client.send(command);
};

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 confirm_mfa_device(
        self,
        user_name,
        device_key,
        device_group_key,
        device_password,
        access_token,
        aws_srp,
    ):
        """
        Confirms an MFA device to be tracked by Amazon Cognito. When a device is
        tracked, its key and password can be used to sign in without requiring a new
        MFA code from the MFA application.

        :param user_name: The user that is associated with the device.
        :param device_key: The key of the device, returned by Amazon Cognito.
        :param device_group_key: The group key of the device, returned by Amazon Cognito.
        :param device_password: The password that is associated with the device.
        :param access_token: The user's access token.
        :param aws_srp: A class that helps with Secure Remote Password (SRP)
                        calculations. The scenario associated with this example uses
                        the warrant package.
        :return: True when the user must confirm the device. Otherwise, False. When
                 False, the device is automatically confirmed and tracked.
        """
        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,
        )
        device_and_pw = f"{device_group_key}{device_key}:{device_password}"
        device_and_pw_hash = aws_srp.hash_sha256(device_and_pw.encode("utf-8"))
        salt = aws_srp.pad_hex(aws_srp.get_random(16))
        x_value = aws_srp.hex_to_long(aws_srp.hex_hash(salt + device_and_pw_hash))
        verifier = aws_srp.pad_hex(pow(srp_helper.val_g, x_value, srp_helper.big_n))
        device_secret_verifier_config = {
            "PasswordVerifier": base64.standard_b64encode(
                bytearray.fromhex(verifier)
            ).decode("utf-8"),
            "Salt": base64.standard_b64encode(bytearray.fromhex(salt)).decode("utf-8"),
        }
        try:
            response = self.cognito_idp_client.confirm_device(
                AccessToken=access_token,
                DeviceKey=device_key,
                DeviceSecretVerifierConfig=device_secret_verifier_config,
            )
            user_confirm = response["UserConfirmationNecessary"]
        except ClientError as err:
            logger.error(
                "Couldn't confirm mfa device %s. Here's why: %s: %s",
                device_key,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise
        else:
            return user_confirm