How can I encrypt data with a public key in Node.js? [duplicate]

Question

In crypto, I see only Signer/Verifier for doing digital signature and Cipher/Decipher with symmetric key encryption.

How do I encrypt data with public key?

Answer 1

As mentioned in the official nodejs api docs here: crypto.publicEncrypt(key, buffer)

Encrypts the content of buffer with key and returns a new Buffer with encrypted content. The returned data can be decrypted using the corresponding private key, for example using crypto.privateDecrypt().

If key is not a KeyObject, this function behaves as if key had been passed to crypto.createPublicKey(). If it is an object, the padding property can be passed. Otherwise, this function uses RSA_PKCS1_OAEP_PADDING.

Because RSA public keys can be derived from private keys, a private key may be passed instead of a public key.

So the answer is:

var encrypted = crypto.publicEncrypt(publicKey, buffer);

Answer 2

You might be interested in my NaCl bindings. From its API:

// Encrypt and sign
box(message, nonce, pubkey, privkey)

// Decrypt and validate
unbox(box, nonce, pubkey, privkey)
// Generates a new keypair, returns {private: <buffer>, public: <buffer>}
boxKeypair()

// Lengths of nonces and public and private keys in bytes
// { nonce: x, pubkey: x, privkey: x }
lengths.box