public ActionResult SignAndEncrypt(SignedAsymmetricModel model)
{
if (model.Action == "encrypt")
{
var plainTextAsBytes = Encoding.Unicode.GetBytes(model.PlainText);
var recipientCertificate = LoadCertificate(model.RecipientThumbprint);
var signingCertificate = LoadCertificate(model.SenderThumbprint);
// Sign message
var signatureContentInfo = new ContentInfo(plainTextAsBytes);
var signedCms = new SignedCms(signatureContentInfo);
var cmsSigner = new CmsSigner(signingCertificate);
signedCms.ComputeSignature(cmsSigner);
var signedMessageAsBytes = signedCms.Encode();
// Encrypt
var encryptedContentInfo = new ContentInfo(signedMessageAsBytes);
var envelopedCms = new EnvelopedCms(encryptedContentInfo);
var cmsRecipient = new CmsRecipient(recipientCertificate);
envelopedCms.Encrypt(cmsRecipient);
var envelopeAsBytes = envelopedCms.Encode();
model.Envelope = Convert.ToBase64String(envelopeAsBytes);
model.PlainText = string.Empty;
}
else if (model.Action == "decrypt")
{
// Decrypt
var cipherTextAsBytes = Convert.FromBase64String(model.Envelope);
var envelopedCms = new EnvelopedCms();
envelopedCms.Decode(cipherTextAsBytes);
envelopedCms.Decrypt();
var encodedSignedCMS = envelopedCms.Encode();
var signedCms = new SignedCms();
signedCms.Decode(encodedSignedCMS);
signedCms.CheckSignature(true);
var plainTextAsBytes = signedCms.ContentInfo.Content;
model.PlainText = UnicodeEncoding.Unicode.GetString(plainTextAsBytes);
model.SenderSubject = signedCms.SignerInfos[0].Certificate.Subject;
model.Envelope = string.Empty;
}
model.RecipientThumbprint = RecipientThumbprint;
model.SenderThumbprint = SenderThumbprint;
ModelState.Clear();
return(View(model));
}