Node.js crypto.secureHeapUsed() Method

The crypto.secureHeapUsed() method in Node.js is used to get the amount of memory used by the secure heap of the running Node.js process. The secure heap is a section of memory that is reserved for cryptographic operations in the Node.js process. This memory is separate from the main heap, which is used for general-purpose memory allocation in the process.

Syntax:

crypto.secureHeapUsed()

Parameters: This method does not take any parameters

Return Value: This method returns an object indicating the amount of secure memory used by the crypto module, in bytes.

Steps to use crypto.secureHeapUsed() method:

Step 1: In order to use crypto.secureHeapUsed(), you need to import the crypto module in your Node.js application using the following statement.

const crypto = require('crypto');

Step 2: Perform some cryptographic operations, Let’s generate a random key and compute a hash:

const key = crypto.randomBytes(32);
const hash = crypto.createHash('sha256')
    .update('GeeksForGeeks').digest('hex');

Step 3: Now call the crypto.secureHeapUsed() method to get the amount of memory used by the secure heap:

const bytesUsed = crypto.secureHeapUsed();
console.log(`Heap used by this process: ${bytesUsed} bytes`);

Example 1:

Javascript

const crypto = require('crypto');
 
// Perform some cryptographic operations
const key = crypto.randomBytes(256);

const hash = crypto.createHash('sha256')

    .update('GeeksForGeeks').digest('hex');
 
// Get the amount of memory used by the secure heap
const bytesUsed = crypto.secureHeapUsed();
 
console.log(`Secure heap used: ${bytesUsed.used}`);

Output:

Secure heap used: 16384

Example 2:

Javascript

const crypto = require('crypto');
 
function generateRandomNumbers(num) {

    const rand = crypto.randomBytes(num);
 
    // Calculating the secure heap used after

    // doing the cryptographic operation

    console.log(`Bytes used: 

        ${crypto.secureHeapUsed().used} bytes`);
}
 
// Making a function call to 
// generate 64 random bytes
generateRandomNumbers(64);