TwoFactorPasswordGenerator (javadoc 2024.12-174331 API)

All Known Implementing Classes:

MockTwoFactorPasswordGenerator, TwoFactorPasswordGeneratorImpl
```
public interface TwoFactorPasswordGenerator
```
Generates TOTP passwords (RFC 6238) with HMAC algorithm for two-factor authentication by secret key and timestamp The hash function that is used in HMAC is SHA-1 (Can be extended to SHA-2 family, depends on authenticator apps).

Author:

Daniil Boger

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`Set<Integer>`	`generatePasswords(String secretKey, long timestampSec)`	Generates and returns all TOTP passwords that will be considered as correct, using secret key and UNIX timestamp.
`Set<String>`	`generateRecoveryKeys()`	Generates set of recovery keys with cryptographically strong generator.
`String`	`generateSecretKey()`	Generates secret key with cryptographically strong generator

- Method Detail
  - generatePasswords
```
@NotNull
Set<Integer> generatePasswords(@NotNull
                               String secretKey,
                               long timestampSec)
```
    Generates and returns all TOTP passwords that will be considered as correct, using secret key and UNIX timestamp. The multiple correct passwords are allowed to prevent time desynchroniation between client and server. For example, password from previous 30-sec. epoch can be allowed.
    
    Parameters:
    
    secretKey - secret key
    
    timestampSec - current UNIX timestamp in seconds
    
    Returns:
    
    set of all correct password
  - generateSecretKey
```
@NotNull
String generateSecretKey()
```
    Generates secret key with cryptographically strong generator
    
    Returns:
    
    generated secret key
  - generateRecoveryKeys
```
@NotNull
Set<String> generateRecoveryKeys()
```
    Generates set of recovery keys with cryptographically strong generator.
    
    Returns:
    
    set with generated recovery keys