jsoncrypt

Purpose

The jsoncrypt javascript (nodejs) library contains a number of functions that can be used to encrypt, decrypt, sign and hash json objects. The library was created to simplify the use of cryptocraphic operations on json objects.

Getting started

In order to use jsoncrypt use the following steps

1. Create a directory in which you want to create a nodejs (Javascipt) application.
2. Go to this directory and install jsoncrypt with: 'npm install @jorveld/jsoncrypt'
3. Create a javascript file in which you want to use the library and add the following line: const JSONCrypt = require('@jorveld/jsoncrypt'); next call the available functions, for example: RSAPair = JSONCrypt.getRSAPair();

available functionss

jsoncrypt implements the following functions:

Utilty functions: ==> getRSAPair() --> This function returns a 2048 bit RSA public and private key. The function returns a JSON object with two properties:

• publicKey
• privateKey

==> createSyncEncryptionKey() --> This function returns a 32 byte random string, that can be used as key in the 'synchronous' encryption functions.

==> createSyncEncryptionKeyAndIv() --> This function returns a 32 byte random string, to be used as the key and a 16 byte initialisation vector for the 'synchronous' encryption functions

Synchronous encryption functions:

==> cryptSync(inputJSONObjectToBeEncrypted, inputEncryptionKey, inputIv="") --> this function takes a JSONObject and encrypts it using the inputEncryptionKey (using AES). If the inputIv=="", a new initialisation vector is creared. If not, the provied vector is used.

It returns a JSON object with two properties: -iv: this is the random initialisation vector used for the encryption. Please mind: the iv is not secret, it nevertheless needs to be provided to decrypt. -encryptedContent: the encrypted content ==> deCryptSync(inputEncryptedContent, inputEncryptionKey, inputIv) --> this function is used to decrypt a JSON object crypted with cryptSync. The function takes the following parameters:

• inputEncryptedContent. This is the 'encryptedContent' from the cryptSync function.
• inputEncryptionKey. The secret synchronous encryption key used.
• inputIv. The initalisation vector generated by cryptSync.

Example: const JSONCrypt = require('jsoncrypt');

console.log("crypt test");

key=JSONCrypt.createSyncEncryptionKey();

var toBeEncryptedObject = { name: "John Johnson", gender: "male", age: 32 }

console.log("SyncCrypt"); syncCryptResult=JSONCrypt.cryptSync(toBeEncryptedObject, key); console.log("syncCryptResult:"+JSON.stringify(syncCryptResult)); console.log("SyncUncrypt"); syncUnencryptResult=JSONCrypt.deCryptSync(syncCryptResult.encryptedContent,key,syncCryptResult.iv); console.log("syncUnencryptResult:"+JSON.stringify(syncUnencryptResult));

Asynchronous encryption functions: ==>cryptAsync(inputJSONObjectToBeEncrypted, inputPublicKey) --> this function will RSA-encrypt the JSONObject 'inputJSONObjectToBeEncrypted' using the public key 'inputPublicKey'. The function returns the encrypted content as a string. ==>deCryptAsync(inputEncryptedContent, inputPrivateKey) --> this function will decrypt 'inputEncryptedContent' (string) (output of cryptAsync) using the private key 'inputPrivateKey'.

Example:

const JSONCrypt = require('jsoncrypt');

console.log("crypt test");

var toBeEncryptedObject = { name: "John Johnson", gender: "male", age: 32 }

console.log("create RSA Keys"); RSAPair = JSONCrypt.getRSAPair(); console.log("RSAPair:"); console.log(RSAPair);

console.log("AsyncCrypt"); asyncCryptResult=JSONCrypt.cryptAsync(toBeEncryptedObject, RSAPair.publicKey); console.log("asyncCryptResult="+asyncCryptResult);

console.log("AsyncUncrypt"); asyncDecryptResult=JSONCrypt.deCryptAsync(asyncCryptResult, RSAPair.privateKey); console.log("asyncDecryptResult="+asyncDecryptResult);

Hash functions: ==>hash(inputJSONObjectToBeHashed) --> this function will md5-hash the JSON object 'inputJSONObjectToBeHashed'. The funcntions the hash as an output.
==>verifyHash(inputHash, inputJSONObjectToBeVerified) --> This function will check if 'inputJSONObjectToBeVerified' is hashed to 'inputHash'. This function can be used to verify a hash. It returns 'true' if the hash is valid.

Example: const JSONCrypt = require('jsoncrypt');

console.log("crypt test");

var toBeEncryptedObject = { name: "John Johnson", gender: "male", age: 32 }

console.log("Hash"); hashResult=JSONCrypt.hash(toBeEncryptedObject); console.log(hashResult); console.log("Hash verification:"+JSONCrypt.verifyHash(hashResult, toBeEncryptedObject));

sign functions: ==>sign(inputJSONObjectToBeSigned, inputPrivateKey) --> this function is used to aes-256-cbc sign JSON object inputJSONObjectToBeSigned' using RSA private key 'inputPrivateKey'. The output of the function is the signature (as a string). ==>verifySignature(inputSignature, inputPublicKey, inputJSONObjectToBeVerified) --> this function is used to verify if 'inputSignature' was used to sign JSON Object 'inputJSONObjectToBeVerified' using RSA key 'inputPublicKey'. If the signature is valid, 'true' is returned.

Example: const JSONCrypt = require('jsoncrypt');

console.log("crypt test");

var toBeEncryptedObject = { name: "John Johnson", gender: "male", age: 32 }

console.log("Sign"); signature=JSONCrypt.sign(toBeEncryptedObject, RSAPair.privateKey); console.log("signature:"+ signature); console.log("Signature verification:"+JSONCrypt.verifySignature(signature, RSAPair.publicKey, toBeEncryptedObject));

Author

Jorien van Veldhoven

License

MIT license