HOTP Component

Properties   Methods   Events   Config Settings   Errors  

The HOTP component allows creation of HMAC-Based One-Time passwords.

Syntax

TipaHOTP

Remarks

The HOTP component implements the HOTP algorithm defined in RFC 4226 (HMAC-Based One-Time Password). These types of passwords are commonly used as a second factor of authentication in multi-factor authentication scenarios.

To begin specify the shared secret in the Secret property.

Next, you may set Counter. If this property is not set, the component will use a default value.

To create the password call CreatePassword. The Password property will be populated with the new password.

To validate a password set the Password property and call ValidatePassword. The method will return True or False to indicate success or failure.

Property List

The following is the full list of the properties of the component with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the component with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.

Config Settings

The following is a list of config settings for the component with short descriptions. Click on the links for further details.

Counter Property (HOTP Component)

The counter used for HMAC-Based One Time Password creation or validation.

Syntax

property Counter: Int64 read get_Counter write set_Counter;

Default Value

0

Remarks

This property holds the counter value used for HMAC-Based One Time Password creation or validation. This value must be specified before calling CreatePassword or ValidatePassword. The value should be incremented each time a password is created.

The default value is 0.

Password Property (HOTP Component)

The HMAC-Based One Time Password.

Syntax

property Password: String read get_Password write set_Password;

Default Value

''

Remarks

This property holds the HMAC-Based One Time Password. This property is populated after calling CreatePassword. This property must be set before calling ValidatePassword.

Secret Property (HOTP Component)

The Base32 encoded shared secret used when creating and validating a password.

Syntax

property Secret: String read get_Secret write set_Secret;

Default Value

''

Remarks

This property specifies the Base32 encoded shared secret used when creating and validating a password. This should be set before calling CreatePassword or ValidatePassword.

If this is not set before calling CreatePassword a random secret will be automatically generated. This functionality provides an easy way to create new secret values. The length of the secret is defined by SecretLength.

Config Method (HOTP Component)

Sets or retrieves a configuration setting.

Syntax

function Config(ConfigurationString: String): String;

Remarks

Config is a generic method available in every component. It is used to set and retrieve configuration settings for the component.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

CreatePassword Method (HOTP Component)

Creates a HMAC-Based One Time Password.

Syntax

procedure CreatePassword();

Remarks

This method creates a HMAC-Based One Time Password.

The following properties are applicable when calling CreatePassword.

• Secret
• Counter

Calling CreatePassword populates the Password property with the created password.

If Secret is not specified before calling this method a random secret will be automatically generated.

Reset Method (HOTP Component)

Reset the variables to default value.

Syntax

procedure Reset();

Remarks

This method will reset the variables to default value.

ValidatePassword Method (HOTP Component)

Validates a HMAC-Based One Time Password.

Syntax

function ValidatePassword(): Boolean;

Remarks

This method validates a HMAC-Based One Time Password.

The following properties are applicable when calling ValidatePassword.

• Password (required)
• Secret (required)
• Counter (required)

The method will return True if the password is validated, False otherwise.

Error Event (HOTP Component)

Information about errors during data delivery.

Syntax

type TErrorEvent = procedure (
  Sender: TObject;
  ErrorCode: Integer;
  const Description: String
) of Object;

property OnError: TErrorEvent read FOnError write FOnError;

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the component raises an exception.

The ErrorCode parameter contains an error code, and the Description parameter contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

Config Settings (HOTP Component)

HOTP Config Settings

//TOTP
otpauth://totp/MyServiceName:account@company.com?secret=JBSWY3DPEHPK3PXP&digits=6&period=30

//HOTP
otpauth://hotp/MyServiceName:account@company.com?secret=JBSWY3DPEHPK3PXP&digits=6&counter=0

Base Config Settings

Trappable Errors (HOTP Component)

HOTP Errors