Node.js

RSASSA-PSS Sign String to Create Base64 PCKS7 Signature

See more Digital Signatures Examples

Signs a string to create a PKCS7 signature in the base64 encoding. The signature algorithm is RSASSA-PSS with SHA256. 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();

    // Get a digital certificate with private key from a .pfx
    // (Chilkat has many different ways to provide a cert + private key for siging.
    // Using a PFX is just one possible option.)
    var pfx = new chilkat.Pfx();
    success = pfx.LoadPfxFile("qa_data/rsassa-pss/privatekey.pfx","PFX_PASSWORD");
    if (success == false) {
        console.log(pfx.LastErrorText);
        return;
    }

    // Get the certificate to be used for signing.
    // (The typical case for a PFX is that it contains a cert with an associated private key,
    // as well as other certificates in the chain of authentication.  The cert with the private
    // key should be in the first position at index 0.)

    var cert = new chilkat.Cert();
    success = pfx.CertAt(0,cert);
    if (success == false) {
        console.log(pfx.LastErrorText);
        return;
    }

    crypt.SetSigningCert(cert);

    // Indicate that RSASSA-PSS with SHA256 should be used.
    crypt.SigningAlg = "pss";
    crypt.HashAlgorithm = "sha256";

    crypt.EncodingMode = "base64";

    // Sign a string and return the base64 PKCS7 detached signature
    var originalText = "This is a test";
    var pkcs7sig = crypt.SignStringENC(originalText);
    console.log("Detached Signature:");
    console.log(pkcs7sig);

    // This signature looks like this:
    // MIIG5wYJKoZIhvcNAQcCoIIG2DCCBtQCAQExDzANBgl .. YToLqEwTdU87ox5g7rvw==

    // The ASN.1 of the signature can be examined by browsing to https://lapo.it/asn1js/ ,
    // then copy-and-paste the Base64 signature into the form and decode..

    // The signature can be verified against the original data like this:
    success = crypt.VerifyStringENC(originalText,pkcs7sig);
    console.log("Signature verified: " + success);
    success = crypt.VerifyStringENC("Not the original text",pkcs7sig);
    console.log("Signature verified: " + success);

    // Now we'll create an opaque signature (the opposite of a detached signature). 
    // An opaque signature is a PKCS7 message that contains both the original data and
    // the signature.  The verification process extracts the original data.
    var opaqueSig = crypt.OpaqueSignStringENC(originalText);
    console.log("Opaque Signature:");
    console.log(opaqueSig);

    // The ASN.1 of the signature can be examined by browsing to https://lapo.it/asn1js/ ,
    // then copy-and-paste the Base64 signature into the form and decode..

    // We can verify and extract the original data:
    var origTxt = crypt.OpaqueVerifyStringENC(opaqueSig);
    if (crypt.LastMethodSuccess !== true) {
        console.log("Signature verification failed.");
        console.log(crypt.LastErrorText);
        return;
    }

    console.log("Signature verified.");
    console.log("Extracted text:" + origTxt);

}

chilkatExample();