Encrpyt with RSA/ECB/OAEPWithSHA-1AndMGF1Padding in C#

Question

I need to encrypt some text in C# .NET 4.7.2 and the cipher i need to use is RSA/ECB/OAEPWithSHA-1AndMGF1Padding. However the built-in C# class, RSACryptoServiceProvider doesn't seem to have MGF1 padding.

How do I encrypt with a public key and RSA/ECB/OAEPWithSHA-1AndMGF1Padding?

The code I currently have:

var cert = new X509Certificate2('path to certificate');
var rsa = cert.PublicKey.Key as RSACryptoServiceProvider;
var dataToEncrypt = ASCIIEncoding.ASCII.GetBytes(data);
var encryptedByteArray = rsa.Encrypt(dataToEncrypt, true).ToArray();

return Convert.ToBase64String(encryptedByteArray);

Answer 1

RSA rsa = ...;
byte[] encrypted = rsa.Encrypt(data, RSAEncryptionPadding.OaepSha1);

MGF-1 is the only Mask Generation Function defined by RFC thus far, so it is implied.

Also, try to avoid using RSACryptoServiceProvider directly. If you’re on an old version and have to, then passing true to its fOAEP parameter is the same as requesting OaepSha1 from the new overload.