Node.js

Verify an RSA Signature Against the Signed Hash

See more Apple Keychain Examples

Demonstrates how to validate an RSA Signature against the hash that was signed. Node.js

NODEJS_PRELUDE

function chilkatExample() {

    var success = false;

    var bd = new chilkat.BinData();
    var i;
    for (i = 0; i <= 100; i++) {
        bd.AppendEncoded("000102030405060708090A0B0C0D0E0F","hex");
    }

    var sha256_base64 = bd.GetHash("sha256","base64");
    console.log("sha256 hash in base64 format: " + sha256_base64);

    var base64_rsa_sig = "AwF2BbOvL6jA5DwmMAc9n6J2Cc8PI6Rj5W079+aKJcIEtPWRzHor0Bvc3aftGM3Jbgj6SXlIC3M3RYS7UZOnfiHKFNZgbxaNT5WwsWooK42ZkC8DBZl0p7OunBUKd5SciUo+TKilioeUkriN3L1Zl9hwi3HVDVqgVo3XXskwIftSqLSFlepTLTmOWj9Y93dp8J4D9RyLtNgFQBc0WB22tyJTsuY56mLcWe1AMF3LizB9OrbwjynF2u16xWlrJdugccz795fJBUV9aQSD+8S3KeqwQhoi8RK1uhD68aGCyaSpBq0NZ8COAkn7MXaF4POxrAAt8udfHM+PRfSOptcH/w==";

    //  Get the public key to be used for signature verification.
    var pubKey = new chilkat.PublicKey();
    success = pubKey.LoadFromFile("rsaKeys/chilkat-rsa-2048.pem");
    if (success == false) {
        console.log(pubKey.LastErrorText);
        return;
    }

    var rsa = new chilkat.Rsa();
    success = rsa.UsePublicKey(pubKey);
    if (success == false) {
        console.log(rsa.LastErrorText);
        return;
    }

    //  Verify the hash against the signature.
    rsa.EncodingMode = "base64";
    success = rsa.VerifyHashENC(sha256_base64,"sha256",base64_rsa_sig);

    if (success == false) {
        console.log(rsa.LastErrorText);
        console.log("Signature invalid.");
    }
    else {
        console.log("Signature valid.");
    }


}

chilkatExample();