Dart

Duplicate OpensSSL to Create Signature using Cert and Key Files

See more OpenSSL Examples

This example duplicates the following:

openssl smime –sign -in something.xml -out something.der -signer mycert.crt -inkey cert.key -outform der –nodetach

Note: Although "smime" is the OpenSSL command, it's not actually producing S/MIME. The arguments "-outform der -binary" indicates that the output is binary DER (i.e. the PKCS7 binary signature). The input can be any type of file: XML, PDF, JPG, ... *anything*...

Dart

import 'package:chilkat/chilkat.dart';

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

  final crypt = CkCrypt2();

  // Load the cert and private key from separate files.
  final cert = CkCert();
  try {
    cert.loadFromFile('myCert.crt');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final bd = CkBinData();
  bd.loadFile('cert.key');
  final privkey = CkPrivateKey();
  // Load from any format private key.
  // If the file does not need a password, the 2nd arg is ignored.
  try {
    privkey.loadAnyFormat(bd, 'password_if_needed');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  try {
    crypt.setSigningCert2(cert, privkey);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Create the opaque signature (PKCS7 binary DER that contains both the signature and original file data).
  try {
    crypt.createP7M('qa_data/infile.anything', 'qa_output/outfile.der');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Success.');
}