How does NPM ensure the security of installed packages?

Let's learn how npm packages are secured during and after installation.

We are all used to installing NPM packages for React, Express, and other Node.js-based projects.

However, it is important to know how NPM secures the packages installed so that no tempered package can be installed in the codebase. I learned about these concepts when publishing internal npm packages for my company.

NPM uses these approaches:

1. Signing the package:
A package's validity is verified cryptographically when it is published to the NPM registry and signed with the author's private key.

To confirm that the package has not been tampered with during installation, npm checks the signature against the author's public key.

2. Integrity hash in package-lock.json file:

Each package has its own "integrity" field in the "package-lock.json" file. The package's contents, including any required dependencies, their respective versions, and the SHA-512 hash, are hashed and stored in this field.

Each time you use the "npm install" command to update your project, npm will check the integrity hash of each package and its dependencies against the one saved in the "package-lock.json" file.

If the hashes are the same, the package has not been tampered with, and the installation can continue. If the hashes don't match, npm won't install the package since it thinks it's fake.

3. Scanning for vulnerabilities:

NPM's "npm audit" tool examines the currently installed packages for known security flaws and suggests solutions. This aids in making sure the packages being used have no known security flaws.

There are other recommended approaches, but these three are widely used.

Thanks for reading.