React Native Requires Chilkat v11.0.0+

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. React Native

import { BinData, Cert, CertChain, Crypt2 } from '@chilkat/react-native'

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

  const crypt = new Crypt2();

  // Verify a PKCS7 signed-data (opaque signature) file and extract the original content to a file.
  try {
    crypt.verifyP7M('qa_data/p7m/opaqueSig.p7', 'qa_output/originalData.dat');
  } catch {
    console.log(crypt.lastErrorText);
    return;
  }

  // Alternatively, we can do it in memory...
  const binData = new BinData();
  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.
  try {
    crypt.opaqueVerifyBd(binData);
  } catch {
    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.
  const cert = new Cert();
  const certChain = new CertChain();
  const numCerts = crypt.numSignerCerts;
  let i = 0;
  while (i < numCerts) {
    crypt.lastSignerCert(i, cert);
    console.log(cert.subjectDN);

    try {
      cert.buildCertChain(certChain);
    } catch {
      console.log(cert.lastErrorText);
      return;
    }

    i++;
  }
}