Golang RSA encrypt and decrypt example

rsa.go

package crypto

import (
	"crypto/rand"
	"crypto/rsa"
	"crypto/sha256"
)

func RSAGenerateKey() (*rsa.PrivateKey, *rsa.PublicKey) {
	// here 2048 is the number of bits for RSA
	// 1024 - 4096 supported
	privateKey, err := rsa.GenerateKey(rand.Reader, 2048)
	if err != nil {
		panic(err)
	}
	publicKey := &privateKey.PublicKey
	return privateKey, publicKey
}

func RSAEncrypt(data []byte, pubKey rsa.PublicKey) []byte {
	label := []byte("OAEP Encrypted")
	rng := rand.Reader
	cipherData, err := rsa.EncryptOAEP(sha256.New(), rng, &pubKey, data, label)
	if err != nil {
		panic(err)
	}
	return cipherData
}

func RSADecrypt(cipherData []byte, privKey rsa.PrivateKey) []byte {
	label := []byte("OAEP Encrypted")
	rng := rand.Reader
	data, err := rsa.DecryptOAEP(sha256.New(), rng, &privKey, cipherData, label)
	if err != nil {
		panic(err)
	}
	return data
}

rsa_test.go

package crypto

import (
	"testing"
)

func TestRSA(t *testing.T) {
	data := []byte("hello world")

	privKey, publicKey := RSAGenerateKey()
	encrypt := RSAEncrypt(data, *publicKey)
	decrypt := RSADecrypt(encrypt, *privKey)

	t.Log(string(decrypt))
}