JavaScript

RSA Hash Binary Data and Sign (and Verify)

See more RSA Examples

Demonstrates how to sign the hash of binary data. Also demonstrates how to verify the RSA signature. JavaScript

var success = false;

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

// Load an RSA private key for signing.
var privKey = new CkPrivateKey();
success = privKey.LoadEncryptedPemFile("qa_data/pem/rsa_passwd.pem","passwd");
if (success == false) {
    console.log(privKey.LastErrorText);
    return;
}

var rsa = new CkRsa();
rsa.UsePrivateKey(privKey);

// We have some binary data (in hex) to sign
var originalData = "0102030405060708090A";
var bdData = new CkBinData();
bdData.AppendEncoded(originalData,"hex");

// Hash (SHA-256) and sign the hash:
var bdSignature = new CkBinData();
success = rsa.SignBd(bdData,"sha256",bdSignature);
if (success == false) {
    console.log(rsa.LastErrorText);
    return;
}

// Show the RSA signature in base64
console.log(bdSignature.GetEncoded("base64"));

// ------------------------------------------
// Get the public key from the private key
var pubKey = new CkPublicKey();
privKey.ToPublicKey(pubKey);

// Verify the signature..
var rsa2 = new CkRsa();
rsa2.UsePublicKey(pubKey);

var bVerified = rsa2.VerifyBd(bdData,"sha256",bdSignature);
console.log("signature verified: " + bVerified);