encryption.js

import * as crypto from 'crypto'

const ALGORITHM = {
	BLOCK_CIPHER: 'aes-256-gcm',
	AUTH_TAG_BYTE_LEN: 16,
	IV_BYTE_LEN: 12,
	KEY_BYTE_LEN: 32,
	SALT_BYTE_LEN: 16
}

const getIV = (): Buffer => crypto.randomBytes(ALGORITHM.IV_BYTE_LEN)
const key = process.env.ENCRYPTION_KEY!

export const encrypt = (text) => {
	const keyBuffer = Buffer.from(key, 'hex')
	const iv = getIV()
	const cipher = crypto.createCipheriv(
		ALGORITHM.BLOCK_CIPHER,
		keyBuffer,
		iv,
		{authTagLength: ALGORITHM.AUTH_TAG_BYTE_LEN}
	)
	let encryptedMessage = cipher.update(text, 'utf8')
	encryptedMessage = Buffer.concat([encryptedMessage, cipher.final()])
	return Buffer.concat([iv, encryptedMessage, cipher.getAuthTag()]).toString(
		'hex'
	)
}

export const decrypt = (ciphertext) => {
	const keyBuffer = Buffer.from(key, 'hex')
	const ciphertextBuffer = Buffer.from(ciphertext, 'hex')
	const authTag = ciphertextBuffer.slice(-16)
	const iv = ciphertextBuffer.slice(0, 12)
	const encryptedMessage = ciphertextBuffer.slice(12, -16)
	const decipher = crypto.createDecipheriv(
		ALGORITHM.BLOCK_CIPHER,
		keyBuffer,
		iv,
		{authTagLength: ALGORITHM.AUTH_TAG_BYTE_LEN}
	)
	decipher.setAuthTag(authTag)
	let text = decipher.update(encryptedMessage)
	text = Buffer.concat([text, decipher.final()])
	return text.toString('utf8')
}

export const sha256Encrypt = (data, key) => {
	const hmac = crypto.createHmac('sha256', key)
	hmac.update(data)
	return hmac.digest('hex')
}