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@rbrayb
Created July 26, 2018 01:13
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C# CNG library
using System;
using System.Security.Cryptography;
namespace CNGMediumConsoleApp
{
class Program
{
static byte[] data = {0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20};
static byte[] privateKey;
static byte[] publicKey;
private static byte[] encrypted;
private static byte[] decrypted;
private static byte[] signed;
static void Main(string[] args)
{
try
{
CngKey cngKey;
CngKeyCreationParameters cng = new CngKeyCreationParameters
{
KeyUsage = CngKeyUsages.AllUsages
};
if (!CngKey.Exists("rsaKey"))
cngKey = CngKey.Create(CngAlgorithm.Rsa, "rsaKey", cng);
else
cngKey = CngKey.Open("rsaKey");
RSACng rsaKey = new RSACng(cngKey)
{
KeySize = 2048
};
// Try importing / exporting to blobs (Example only)
byte[] rsaPrvKeyExport = rsaKey.Key.Export(CngKeyBlobFormat.GenericPrivateBlob);
byte[] rsaPubKeyExport = rsaKey.Key.Export(CngKeyBlobFormat.GenericPublicBlob);
CngKey cngPrv = CngKey.Import(rsaPrvKeyExport, CngKeyBlobFormat.GenericPrivateBlob);
CngKey cngPub = CngKey.Import(rsaPubKeyExport, CngKeyBlobFormat.GenericPublicBlob);
// Try importing / exporting to parameters (Example only)
RSAParameters pub = rsaKey.ExportParameters(false);
RSAParameters prv = rsaKey.ExportParameters(true);
RSACng rsaPrv = new RSACng();
rsaPrv.ImportParameters(prv);
RSACng rsaPub = new RSACng();
rsaPub.ImportParameters(pub);
// These are our keys
privateKey = rsaKey.Key.Export(CngKeyBlobFormat.GenericPrivateBlob);
publicKey = rsaKey.Key.Export(CngKeyBlobFormat.GenericPublicBlob);
string prvResult = ByteArrayToHexString(privateKey, 0, privateKey.Length);
string pubResult = ByteArrayToHexString(publicKey, 0, publicKey.Length);
Console.WriteLine("\nPrivate key - length = " + privateKey.Length + "\n" + prvResult + "\n");
Console.WriteLine("\nPublic key - length = " + publicKey.Length + "\n" + pubResult + "\n");
// Encrypt / decrypt
encrypted = Encrypt(publicKey, data);
decrypted = Decrypt(privateKey, encrypted);
bool result = ByteArrayCompare(data, decrypted);
if (result)
Console.WriteLine("Encrypt / decrypt works");
else
Console.WriteLine("Encrypt / decrypt fails");
// Signing
signed = Sign512(data, privateKey);
bool result1 = VerifySignature512(data, signed, publicKey);
if (result1)
Console.WriteLine("Signing works");
else
Console.WriteLine("Signing fails");
}
catch (Exception e)
{
Console.WriteLine("Exception " + e.Message);
}
Console.ReadLine();
}
static bool ByteArrayCompare(byte[] a1, byte[] a2)
{
if (a1.Length != a2.Length)
return false;
for (int i = 0; i < a1.Length; i++)
if (a1[i] != a2[i])
return false;
return true;
}
public static string ByteArrayToHexString(byte[] bytes, int start, int length)
{
string delimitedStringValue = BitConverter.ToString(bytes, start, length);
return delimitedStringValue.Replace("-", "");
}
public static byte[] Sign512(byte[] data, byte[] privateKey)
{
CngKey key = CngKey.Import(privateKey, CngKeyBlobFormat.GenericPrivateBlob);
RSACng crypto = new RSACng(key);
return crypto.SignData(data, HashAlgorithmName.SHA512, RSASignaturePadding.Pkcs1);
}
public static bool VerifySignature512(byte[] data, byte[] signature, byte[] publicKey)
{
CngKey key = CngKey.Import(publicKey, CngKeyBlobFormat.GenericPublicBlob);
RSACng crypto = new RSACng(key);
return crypto.VerifyData(data, signature, HashAlgorithmName.SHA512, RSASignaturePadding.Pkcs1);
}
public static byte[] Encrypt(byte[] publicKey, byte[] data)
{
CngKey key = CngKey.Import(publicKey, CngKeyBlobFormat.GenericPublicBlob);
RSACng crypto = new RSACng(key);
var result = crypto.Encrypt(data, RSAEncryptionPadding.OaepSHA512);
return result;
}
public static byte[] Decrypt(byte[] privateKey, byte[] data)
{
CngKey key = CngKey.Import(privateKey, CngKeyBlobFormat.GenericPrivateBlob);
RSACng crypto = new RSACng(key);
var result = crypto.Decrypt(data, RSAEncryptionPadding.OaepSHA512);
return result;
}
}
}
@rbrayb
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rbrayb commented Jul 30, 2018

@debs1979
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debs1979 commented Jan 7, 2021

Thanks for this code.

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