JavaScript

Verify Opaque Signature and Retrieve Signing Certificates

See more Digital Signatures Examples

Demonstrates how to verify a PCKS7 opaque digital signature (signed data), extract the original file/data, and then extract the certificate(s) that were used to sign. JavaScript

var success = false;

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

var crypt = new CkCrypt2();

// Verify a PKCS7 signed-data (opaque signature) file and extract the original content to a file.
success = crypt.VerifyP7M("qa_data/p7m/opaqueSig.p7","qa_output/originalData.dat");
if (success == false) {
    console.log(crypt.LastErrorText);
    return;
}

// Alternatively, we can do it in memory...
var binData = new CkBinData();
success = binData.LoadFile("qa_data/p7m/opaqueSig.p7");
// Your app should check for success, but we'll skip the check for brevity..

// If verified, the signature is unwrapped and binData is replaced with the original data that was signed.
success = crypt.OpaqueVerifyBd(binData);
if (success == false) {
    console.log(crypt.LastErrorText);
    return;
}

// For our testing, we signed some text, so we can get it from the binData..
console.log("Original Data:");
console.log(binData.GetString("utf-8"));

// After any method call that verifies a signature, the crypt object will contain the certificate(s)
// that were used for signing (assuming the X.509 certs were available in the signature, which is typically the case).

// Get each signing certificate, and build the certificate chain for each.
var cert = new CkCert();
var certChain = new CkCertChain();
var numCerts = crypt.NumSignerCerts;
var i = 0;
while (i < numCerts) {
    crypt.LastSignerCert(i,cert);
    console.log(cert.SubjectDN);

    success = cert.BuildCertChain(certChain);
    if (success == false) {
        console.log(cert.LastErrorText);
        return;
    }

    i = i+1;
}