HmacOTP (Keycloak Docs Distribution 21.0.2 API)

java.lang.Object
- org.keycloak.models.utils.HmacOTP

Direct Known Subclasses:

TimeBasedOTP
```
public class HmacOTP
extends Object
```
Version:

$Revision: 1 $

Author:

Bill Burke

Field Summary

Fields
Modifier and Type	Field	Description
`protected String`	`algorithm`
`static String`	`DEFAULT_ALGORITHM`
`static int`	`DEFAULT_NUMBER_DIGITS`
`static String`	`HMAC_SHA1`
`static String`	`HMAC_SHA256`
`static String`	`HMAC_SHA512`
`protected int`	`lookAheadWindow`
`protected int`	`numberDigits`

Constructor Summary

Constructors
Constructor Description

HmacOTP(int numberDigits, String algorithm, int delayWindow)

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`String`	`generateHOTP(String key, int counter)`
`String`	`generateOTP(String key, String counter, int returnDigits, String crypto)`	This method generates an OTP value for the given set of parameters.
`static String`	`generateSecret(int length)`
`int`	`validateHOTP(String token, String key, int counter)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

HMAC_SHA1
```
public static final String HMAC_SHA1
```
See Also:

Constant Field Values

HMAC_SHA256
```
public static final String HMAC_SHA256
```
See Also:

Constant Field Values

HMAC_SHA512
```
public static final String HMAC_SHA512
```
See Also:

Constant Field Values

DEFAULT_ALGORITHM

public static final String DEFAULT_ALGORITHM

See Also:: Constant Field Values

DEFAULT_NUMBER_DIGITS
```
public static final int DEFAULT_NUMBER_DIGITS
```
See Also:

Constant Field Values

algorithm
```
protected final String algorithm
```

numberDigits
```
protected final int numberDigits
```

lookAheadWindow
```
protected final int lookAheadWindow
```

Constructor Detail

HmacOTP

public HmacOTP(int numberDigits,
               String algorithm,
               int delayWindow)

Method Detail
- generateSecret
```
public static String generateSecret(int length)
```
- generateHOTP
```
public String generateHOTP(String key,
                           int counter)
```
- validateHOTP
```
public int validateHOTP(String token,
                        String key,
                        int counter)
```
  Parameters:
  
  token -
  
  key -
  
  counter -
  
  Returns:
  
  -1 if not a match. A positive number means successful validation. This positive number is also the new value of the counter
- generateOTP
```
public String generateOTP(String key,
                          String counter,
                          int returnDigits,
                          String crypto)
```
  This method generates an OTP value for the given set of parameters.
  
  Parameters:
  
  key - the shared secret, HEX encoded
  
  counter - a value that reflects a time
  
  returnDigits - number of digits to return
  
  crypto - the crypto function to use
  
  Returns:
  
  A numeric String in base 10 that includes return digits
  
  Throws:
  
  GeneralSecurityException