encodePrivateKeyToPemPKCS1 function

Uint8List encodePrivateKeyToPemPKCS1(RSAPrivateKey privateKey)

Implementation

Uint8List encodePrivateKeyToPemPKCS1(RSAPrivateKey privateKey) {
  var topLevel = ASN1Sequence();

  var version = ASN1Integer(BigInt.from(0));
  var modulus = ASN1Integer(privateKey.n);
  var publicExponent = ASN1Integer(privateKey.exponent);
  var privateExponent = ASN1Integer(privateKey.d);
  var p = ASN1Integer(privateKey.p);
  var q = ASN1Integer(privateKey.q);
  var dP = privateKey.d! % (privateKey.p! - BigInt.from(1));
  var exp1 = ASN1Integer(dP);
  var dQ = privateKey.d! % (privateKey.q! - BigInt.from(1));
  var exp2 = ASN1Integer(dQ);
  var iQ = privateKey.q?.modInverse(privateKey.p!);
  var co = ASN1Integer(iQ);

  topLevel.add(version);
  topLevel.add(modulus);
  topLevel.add(publicExponent);
  topLevel.add(privateExponent);
  topLevel.add(p);
  topLevel.add(q);
  topLevel.add(exp1);
  topLevel.add(exp2);
  topLevel.add(co);

  return topLevel.encode();
}