JavaScript

Duplicate openssl pkey -in private.pem -pubout -out pubkey.pem

See more OpenSSL Examples

How to output the public part of a private key: Demonstrates how to duplicate this OpenSSL command:

openssl pkey -in private.pem -pubout -out pubkey.pem

JavaScript

var success = false;

var pkey = new CkPrivateKey();

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

var pubKey = new CkPublicKey();
pkey.ToPublicKey(pubKey);

success = pubKey.SavePemFile(false,"pubKey.pem");
if (success !== true) {
    console.log(pubKey.LastErrorText);

    return;
}

console.log("Success.");