SCryptUtil

java.lang.Object
- com.lambdaworks.crypto.SCryptUtil

```
public class SCryptUtil
extends java.lang.Object
```
Simple SCrypt interface for hashing passwords using the scrypt key derivation function and comparing a plain text password to a hashed one. The hashed output is an extended implementation of the Modular Crypt Format that also includes the scrypt algorithm parameters. Format: $s0$PARAMS$SALT$KEY.

PARAMS
32-bit hex integer containing log2(N) (16 bits), r (8 bits), and p (8 bits)

SALT
base64-encoded salt

KEY
base64-encoded derived key

s0 identifies version 0 of the scrypt format, using a 128-bit salt and 256-bit derived key.

Constructor Summary

Constructors
Constructor Description

SCryptUtil()

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static boolean`	`check(java.lang.String passwd, java.lang.String hashed)`	Compare the supplied plaintext password to a hashed password.
`private static int`	`log2(int n)`
`static java.lang.String`	`scrypt(java.lang.String passwd, int N, int r, int p)`	Hash the supplied plaintext password and generate output in the format described in `SCryptUtil`.

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

- Constructor Detail
  - SCryptUtil
```
public SCryptUtil()
```
- Method Detail
  - scrypt
```
public static java.lang.String scrypt(java.lang.String passwd,
                                      int N,
                                      int r,
                                      int p)
```
    Hash the supplied plaintext password and generate output in the format described in SCryptUtil.
    
    Parameters:
    
    passwd - Password.
    
    N - CPU cost parameter.
    
    r - Memory cost parameter.
    
    p - Parallelization parameter.
    
    Returns:
    
    The hashed password.
  - check
```
public static boolean check(java.lang.String passwd,
                            java.lang.String hashed)
```
    Compare the supplied plaintext password to a hashed password.
    
    Parameters:
    
    passwd - Plaintext password.
    
    hashed - scrypt hashed password.
    
    Returns:
    
    true if passwd matches hashed value.
  - log2
```
private static int log2(int n)
```