(Node.js) RSA SHA256 Signature using Private Key from Java Keystore

Signs plaintext using RSA SHA256 using a key from a Java keystore.

Duplicatest this code:

KeyStore keystore; // key repository for keys containing signature certificate
String alias; // alias for the certificate in the key repository
String password; // password for the certificate's private key
String plaintext; // text being signed


Signature signature = Signature.getInstance("SHA256withRSA");
signature.initSign((PrivateKey) keystore.getKey(alias, password.toCharArray()));
signature.update(plaintext.getBytes("UTF-8"));
byte[] rsa_text= signature.sign();

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

    // This requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    var jks = new chilkat.JavaKeyStore();

    var jksPassword = "secret";

    // Load the Java keystore from a file.  The JKS file password is used
    // to verify the keyed digest that is found at the very end of the keystore.
    // It verifies that the keystore has not been modified.
    var success = jks.LoadFile(jksPassword,"qa_data/jks/sample_secret.jks");
    if (success !== true) {
        console.log(jks.LastErrorText);
        return;
    }

    // Get the private key from the JKS.
    // The private key password may be different than the file password.
    var privKeyPassword = "secret";
    var caseSensitive = false;
    // privKey: PrivateKey
    var privKey = jks.FindPrivateKey(privKeyPassword,"some.alias",caseSensitive);
    if (jks.LastMethodSuccess !== true) {
        console.log(jks.LastErrorText);
        return;
    }

    // Establish the RSA object and tell it to use the private key..
    var rsa = new chilkat.Rsa();

    success = rsa.ImportPrivateKeyObj(privKey);

    if (success !== true) {
        console.log(rsa.LastErrorText);
        return;
    }

    // Indicate we'll be signing the utf-8 byte representation of the string..
    rsa.Charset = "utf-8";

    // Sign some plaintext using RSA-SHA256

    var plaintext = "this is the text to be signed";
    binarySignature = rsa.SignString(plaintext,"SHA256");
    if (rsa.LastMethodSuccess !== true) {
        console.log(rsa.LastErrorText);
        return;
    }

    // Alternatively, if the signature is desired in some encoded string form,
    // such as base64, base64-url, hex, etc.
    rsa.EncodingMode = "base64-url";
    var signatureStr = rsa.SignStringENC(plaintext,"SHA256");
    console.log("base64-url RSA signature: " + signatureStr);

}

chilkatExample();