Cryptography in Node.JS

Introduction

For software development, cryptography is essential. Data must be safeguarded. A study of data security methods is known as cryptography. It turns plaintext into encrypted text and vice versa, transforming the information into a secret. As a result, only the receiver and the sender of that data can comprehend its contents.

A cryptosystem is made up of three basic parts: plaintext, ciphertext, and algorithm. We employ a cypher and an algorithm that converts plaintext into ciphertext to conceal information. Data is encrypted when it is made into unintelligible text, and it is returned to plaintext when data is decrypted.

A key is used by cryptographic algorithms to change plaintext into ciphertext. If you have the correct key on hand, it is feasible to convert the ciphertext back to plaintext.

If you use the same key to encrypt and decode data, you are utilizing symmetric encryption. If different keys are utilized for encryption and decryption, asymmetric encryption is employed. You must keep hashed passwords in the database to secure data in Node.js apps. In this manner, material that has been hashed cannot be decoded into plaintext. It needs to be confirmed. The data is encrypted, so even if malevolent attackers get to access the database, they won't be able to read it. Furthermore, they lack the key that would enable them to do so.

Both encryption and decoding work to increase security. Data that is exchanged across a network or kept in a database is secured using cryptography. This tutorial will teach you how to encrypt and decode data in your applications using the Node.js crypto module. It will also provide a node.js cryptography summary.

Mechanism in Cryptography

Hashing :-

A succession of ordinary text is essentially transformed into Ciphertext in this process. Since we are unable to change this encrypted text back to the plain text again, this cryptographic algorithm is one-way.

This technique is mostly utilized when supplying sensitive passwords to systems for user authentication. These ciphertexts will be kept on file since passwords cannot be. Message Digest 5 (MD5), RSA, SHA, and other widely used hashing algorithms are a few examples of prominent hashing algorithms.

Encryption and Decryption:-

A secret key is used in this process to encrypt a string of plain text, which is subsequently decrypted using the same key. Without a secret key, it is impossible to decrypt the text and restore the original text.

This algorithm accepts as inputs encrypted text and a secret key, and it outputs the original text. Most messaging systems employ this approach to guard against data leaks of any kind on the network. AES, DES, etc., are a few common techniques.

Node.js Crypto Module

To help you secure your Node.js application, the Node.js crypto module offers cryptographic operations. In addition to cyphers and deciphers, it provides hashes and HMAC for authentication.

Crypto is a built-in library in Node.js, as was already mentioned. As a result, it doesn't need to be downloaded or set up before being used in Node.js apps. The data encryption and decryption algorithm are handled by the crypto module.

Before putting information into a database, you can hash plain texts with the help of the crypto module. Like encrypted data, hashed data cannot be decoded using a specific key. Instead, a Hash-based Message Authentication Code (HMAC) is in charge of hashing keys and data to produce a final hash.

For transmission, you might want to encrypt and decrypt data. Here are the cypher and decipher functions. You use a cypher function to encrypt data and a decipher function to decode it. Before putting data in the database, you can also want to encrypt it.

To validate passwords that have been encrypted or hashed. It is preferable to have a verify function. Let us just look at the decryption and encryption of data and how to use crypto to build Node.js applications.

Features of Crypto Module

• Easy to use- The crypto module has a very easy-to-follow pattern of use.
• Widely used algorithms- There are a large number of algorithms that can be used for both hashing and cyphers with multiple options. They are dependent on the OpenSSL of the system.
• Cleaner and Consistent Code- The crypto module’s utilities can be easily embedded in the business logic of the code without building any inconsistency in the code.
• Easy Integration- The crypto module is a built-in module in Node.js and its functions can be easily used in the logic of the application.

Usage of Crypto Module

Numerous types of OpenSSL cryptographic functions are wrapped under the crypto module. It can perform hash computations, HMAC authentication, cyphers, and much more!

The crypto module's primary function is to implement cryptographic protocols like TLS and https. The built-in tls and https modules should satisfy the majority of users. However, those who want to deal with full-scale cryptography can utilize the crypto module.

Hashing

A hash is a fixed-length string of bits generated from any arbitrary block of source data using some technique and specified stages.

The hash has several properties :

• Fixed length: This means that the hash length remains constant regardless of the input. For instance, regardless of whether the input data is a few bits or a few gigabytes, SHA-256 hashes are always 256 bits long.
• Deterministic: For the same input, you should anticipate receiving the same hash. Hashes are useful for checksums as a result.
• Collision Resistant: When the same hash is calculated for two different data input blocks, a collision occurs. Hash algorithms are designed to clash very rarely; their level of unlikeliness is one of their characteristics. The use case dictates the importance of this attribute.
• Unidirectional: A good hash algorithm is straightforward to use but challenging to undo. This indicates that it is impossible to identify the original set of data given a hash string.

Hash Algorithms That Work With Crypto:

The version of OpenSSL you are using determines the hashes that work with the crypto module. Run 'openssl list -digest-algorithms' from the command line to get a list of hash types if your version of OpenSSL is recent enough. Instead, for older versions, enter openssl list-message-digest-commands

One of the most used hashing algorithms is SHA-256. Older common types, like SHA-1 and MD5, are no longer secure and should no longer be used.

How To Calculate Hashes with Crypto:

The hash string is generated using the crypto module's 'createHash' method. The name of the hash algorithm is the only parameter this function requires.

It is necessary to push data into the update method so that it may be used by the digest method to turn it into a hash. 'update' can be called numerous times to read streaming data, such as buffers from a file read stream. The output format for the digest function is specified by a parameter that can be either binary, hex, or base64. By default, it's set to binary.

Here is an example to find the hash of a string with the sha-256 algorithm.

The following output will be produced :

Let us take a look at a small example involving the use of the crypto module and a different algorithm.

The following output will be produced :

Encryption/ Decryption

Ciphers enable you to encrypt and decrypt messages using a password.

Cipher Algorithms That Work With Crypto:

The cyphers that operate with crypto, like the hash algorithms, are depending on what your version of OpenSSL provides. You may acquire a list of hash types supported by your OpenSSL by running openssl list-cipher commands. AES 256 is a solid and popular encryption supported by OpenSSL.

How To Use Cipher Algorithms with Crypto:

The crypto module has two methods - one for encrypting and one for decrypting :

• crypto.createCipheriv(algorithm, key, iv)
• crypto.createDecipheriv(algorithm, key, iv)

The first argument is the name of the algorithm as a string. The key is the raw key used by the algorithm, and iv is an initialization vector. key must be secret, and the iv must be unique but need not be secret.

Creates and returns a Cipher object with the given algorithm, key, and initialization vector (iv). iv is required to provide randomness. Randomization is critical for encryption systems to ensure semantic security, which is the feature that repeated use of the scheme under the same key does not allow an attacker to deduce links between encrypted message segments.

Both of the above methods have update functions. The update function returns a chunk of the encoded/decoded data. Hence the digest function is not required to get the result. To get the last chunk of encoded data, you need to call the final method.