Node.js

CMS Sign Hash

Demonstrates how to use the SignHashENC method to sign a pre-computed hash. This method creates a CMS signature (PKCS7 detached signature).

This example requires Chilkat v9.5.0.90 or later.

Node.js

NODEJS_PRELUDE

function chilkatExample() {

    var success = false;

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

    var crypt = new chilkat.Crypt2();

    //  Create the hash to be signed...
    crypt.HashAlgorithm = "sha256";
    crypt.EncodingMode = "base64";
    crypt.Charset = "utf-8";
    //  Create the SHA256 hash of a string using the utf-8 byte representation.
    //  Return the hash as base64.
    var base64Hash = crypt.HashStringENC("This is the string to be hashed");

    //  Load a certificate for signing.
    var cert = new chilkat.Cert();
    success = cert.LoadPfxFile("qa_data/pfx/cert_test123.pfx","test123");
    if (success == false) {
        console.log(cert.LastErrorText);
        return;
    }

    crypt.SetSigningCert(cert);

    //  Sign the hash to create a base64 CMS signature (which does not contain the original data).
    //  We can get the signature in a single line of base64 by specifying "base64", or 
    //  we can get multi-line base64 by specifying "base64_mime".
    crypt.EncodingMode = "base64_mime";
    var base64CmsSig = crypt.SignHashENC(base64Hash,"sha256","base64");
    if (crypt.LastMethodSuccess == false) {
        console.log(crypt.LastErrorText);
        return;
    }

    //  Note: In the above call to SignHashENC, the encoding of the returned CMS signature is specified by the EncodingMode property.
    //  However, the encoding of the passed-in hash is indicated by the 3rd argument.

    console.log("CMS Signature: " + base64CmsSig);

}

chilkatExample();