JavaScript

Duplicate openssl dgst -sha256 -verify pubKey.pem -signature signature.sig in.dat

See more OpenSSL Examples

Demonstrates how to duplicate this OpenSSL command:

openssl dgst -sha256 -verify pubKey.pem -signature signature.sig in.dat

The in.dat file contains the original data that was signed, and can contain text or binary data of any type. The above OpenSSL command does the following:

1. Creates a SHA256 digest of the contents of the input file.
2. Verifies the SHA256 digest using the public key.

JavaScript

var success = false;

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

var pubKey = new CkPublicKey();

// Load the public key from an PEM file:
success = pubKey.LoadFromFile("pubKey.pem");
if (success == false) {
    console.log(pubKey.LastErrorText);
    return;
}

// Load the data of the original file that was signed.
var bdFileData = new CkBinData();
success = bdFileData.LoadFile("in.dat");

// Load the signature.
var bdSig = new CkBinData();
success = bdSig.LoadFile("signature.sig");

var rsa = new CkRsa();

// Import the public key into the RSA component:
success = rsa.UsePublicKey(pubKey);
if (success == false) {
    console.log(rsa.LastErrorText);
    return;
}

// OpenSSL uses big-endian.
rsa.LittleEndian = false;

success = rsa.VerifyBd(bdFileData,"sha256",bdSig);
if (success !== true) {
    console.log(rsa.LastErrorText);
    console.log("The signature was invalid.");
    return;
}

console.log("The signature was verified.");