Node.js crypto.scrypt() Method

The crypto.scrypt() method is an inbuilt application programming interface of the crypto module which is used to enable an implementation of an asynchronous script. Where scrypt is a password-based key derivation function. It is intended to be costly computationally plus memory-wise. So, the brute-force attacks are made unsuccessful.

Syntax:

crypto.scrypt( password, salt, keylen, options, callback )

Parameters: This method accepts five parameters as mentioned above and described below:

password: It can hold string, Buffer, TypedArray, or DataView type of data.
salt: It holds string, Buffer, TypedArray, or DataView type of data. It must be as unique as possible. Moreover, it is suggested that a salt should be random and is at minimum 16 bytes long.
keylen: It is the length of the key and it must be a number.
options: It is of type Object and it has seven parameters namely cost, blockSize, parallelization, N, r, p, and maximum. Where
1. cost: It is a cost parameter for CPU or memory. It is a number and must be a power of two greater but greater than one and by default, its value is 16384.
2. blockSize: It is the parameter for the size of the block allotted. It is a number and the by-default value is 8.
3. parallelization: It is the parameter for Parallelization. It is a number and the by-default value is 1.
4. N: It is an alias for cost. It is a number and only one of both can be defined.
5. r: It is an alias for blockSize. It is a number and only one of both can be defined.
6. p: It is an alias for parallelization. It is a number and only one of both can be defined.
7. maxmem: It is the upper bound for the memory to be used. It is a number and an error can occur when 128 * N * r (approx) is greater than maxmem. The default value is (32 * 1024 * 1024).
callback It is a function with two parameters namely err and derived key.

Return Value: It returns a buffer.

The below examples illustrate the use of crypto.scrypt() method in Node.js:

Example 1:

javascript

// Node.js program to demonstrate the
// crypto.scrypt() method

// Including crypto module
const crypto = require('crypto');

// Calling scrypt method with some of its parameter
crypto.scrypt('GfG', 'ffdgsg', 32, (err, derivedKey) => {

    if (err) throw err;

    // Prints derived key as buffer
    console.log("The derived key1 is :", derivedKey);
});

// Calling scrypt method with the parameter N
crypto.scrypt('GeeksforGeeks', 'tfytdx', 128,
    { N: 512 }, (err, derivedKey) => {

        if (err) throw err;

        // Prints derived key as buffer
        console.log("The derived key2 is :", derivedKey);
        console.log();
    });

Output:

The derived key2 is : 

The derived key1 is :

Example 2:

javascript

// Node.js program to demonstrate the
// crypto.scrypt() method

// Including crypto module
const crypto = require('crypto');

// Defining salt as typed array
const x = new Uint32Array(7);

// Calling scrypt method with some of its parameter
crypto.scrypt('yytunnd', x, 16, (err, derivedKey) => {

    if (err) throw err;

    // Prints derived key which is encoded
    console.log("The derived key1 is :",
        derivedKey.toString("ascii"));
});

// Defining salt as data view
const y = new DataView(new ArrayBuffer(5));

// Calling scrypt method with the parameter N
crypto.scrypt('oksjdjdn', y, 16, { N: 32 },
    (err, derivedKey) => {

        if (err) throw err;

        // Prints derived key after encoding
        console.log("The derived key2 is :",
            derivedKey.toString("base64"));
        console.log();
    });

Output:

The derived key2 is : 6Gu0JKHDSHs0tkTuGYuQ7A==
The derived key1 is : G"@&H 
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Reference: https://nodejs.org/api/crypto.html#crypto_crypto_scrypt_password_salt_keylen_options_callback

Node.js crypto.scrypt() Method

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