RSA Javascript加密和Golang解密

Question

I have a scenario where I need to use RSA public key encryption standard with JavaScript and Golang. I need to encrypt data in JavaScript using public key and decrypt the same in Golang using the private key. I tried using PKCS#1(travst library for JavaScript and crypto/rsa for Golang), but failed in decryption. Can anyone suggest solutions for this?

I tried all possible solutions and researched many documents, but still I couldn't find a proper method. If I do encrypt and decrypt within golang, its working fine. But there is some integration problem between javascript and golang. I am not sure about the padding methodology used in javasript.

This is my golang code to decrypt:

func Decrypt(encryptedData, label []byte) (decryptedData []byte) {
var err error
var block *pem.Block
var private_key *rsa.PrivateKey

if block, _ = pem.Decode([]byte(privatKeyData)); block == nil || block.Type != "RSA PRIVATE KEY" { //privatKeyData is in string format
    log.Fatal("No valid PEM data found")
}

//Read Private Key
if private_key, err = x509.ParsePKCS1PrivateKey(block.Bytes); err != nil {
    log.Fatalf("Private key can't be decoded: %s", err)
}

//Decrypt
if decrypted, err = rsa.DecryptPKCS1v15(rand.Reader, private_key, encryptedData); err != nil {
        log.Println(err)
}
return
}

Answer 1

It's possible to encrypt in javascript and decrypt in Go. Using the library you refer to, jsencrypt:

Create public & private key pair:

openssl genrsa -out key.pem
openssl rsa -in key.pem -pubout > pub.pem

Encryption in javascript:

var encrypt = new JSEncrypt();
encrypt.setPublicKey($('#pubkey').val());

var encrypted = encrypt.encrypt($('#message').val());

$.post("/decrypt", encrypted, function(response) {
    $("#decrypted").val(response);
});

Decryption in Go:

func handleDecrypt(w http.ResponseWriter, r *http.Request) {
    decoder := base64.NewDecoder(base64.StdEncoding, r.Body)
    defer r.Body.Close()
    encrypted, err := ioutil.ReadAll(decoder)
    if err != nil {
        http.Error(w, err.Error(), http.StatusBadRequest)
        return
    }
    data, err := rsa.DecryptPKCS1v15(rand.Reader, privateKey, encrypted)
    if err != nil {
        http.Error(w, "decrypt error", http.StatusBadRequest)
        log.Println(err)
        return
    }
    fmt.Fprint(w, string(data))
}

Update: the privateKey variable is a *rsa.PrivateKey derived from the private key file created by openssl, in this case the "key.pem" file. A pem file is a Base64 encoded DER certificate, eg, -----BEGIN RSA PRIVATE KEY----- and -----END RSA PRIVATE KEY----- show a private key in PEM format. Go standard library provides the x509.ParsePKCS1PrivateKey() method to parse a pem encoded key from a byte slice.

So loading the key into Go might look something like this:

keyBytes, err := ioutil.ReadFile("path/to/key.pem")
if err != nil { ... }

privateKey, err := x509.ParsePKCS1PrivateKey(keyBytes)
if err != nil { ... }