KB-RSA 1.0.4

KB-RSA

A classlibrary project released as nuget that makes it easy to use for key generation, encryption, and decryption with RSA.

All classes in the project are in static structure.

KeySizes

public static class KeySizes {...}

• A list of accepted key sizes for RSA

public enum KeySize 
{
   _384 = 384,
   _392 = 392,
   .
   .
   _2048 = 2048,
   .
   .
   _16384 = 16384
}

RSAKeyModel

public class RSAKeyModel {...}

• Two property to store public and private key

public RSAParameters publicKey { get; set; }
public RSAParameters privateKey { get; set; }

GenerateKey

public static class GenerateKey {...}

key generation processes

• Returns the public and private key it generates according to the key size sent into it as an RSAKeyModel object.

public static RSAKeyModel RSAGenerateKey(KeySize keySize)
{
    int ks = (int)keySize;
    RSAKeyModel model = new RSAKeyModel();
    using (RSACryptoServiceProvider csp = new RSACryptoServiceProvider(ks))
    {
        model.publicKey = csp.ExportParameters(false);
        model.privateKey = csp.ExportParameters(true);
    }
    return model;
}

• It creates a folder on the desktop with the date and time of the day and saves the public and private key it generates according to the key size sent to it.

public static bool RSAGenerateXMLKey(KeySize keySize)
{
    int ks = (int)keySize;
    using (RSACryptoServiceProvider csp = new RSACryptoServiceProvider(ks))
    {
        string filePath = DirectoryControl();
        string publicKeyPath = $@"{filePath}\public.key";
        string privateKeyPath = $@"{filePath}\private.key";
        string publicKey = csp.ToXmlString(false);
        TextWriter publicKeyWriter = new StreamWriter(publicKeyPath);
        publicKeyWriter.WriteLine(publicKey);
        publicKeyWriter.Dispose();
        publicKeyWriter.Close();
        string privateKey = csp.ToXmlString(true);
        TextWriter privateKeyWriter = new StreamWriter(privateKeyPath);
        privateKeyWriter.WriteLine(privateKey);
        privateKeyWriter.Dispose();
        privateKeyWriter.Close();
        }
        return true;
}

DireDirectoryControl() method

private static string DirectoryControl()
{
    string filePath = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);
    filePath += $@"\RSA_XML_Key_{DateTime.Now.ToString("dd-MM-yyyy-HH-mm-ss")}";
    bool folderCheck = File.Exists(filePath);
    if (folderCheck == false)
        Directory.CreateDirectory(filePath);
    string publicKeyPath = $@"{filePath}\public.key";
    bool pubicKeyCheck = File.Exists(publicKeyPath);
    if (pubicKeyCheck == false)
    {
        using (FileStream fs = File.Create(publicKeyPath))
        {
            fs.Dispose();
            fs.Close();
        }
    }
    string privateKeyPath = $@"{filePath}\private.key";
    bool privateKeyCheck = File.Exists(privateKeyPath);
    if (privateKeyCheck == false)
    {
        using (FileStream fs = File.Create(privateKeyPath))
        {
            fs.Dispose();
            fs.Close();
        }
    }
    return filePath;
}

Encrypt

public static class Encrypt {...}

• Encrypts the data with the key of type RSAParameters sent

public static string EncryptWithKey(RSAParameters publicKey, string data)
{
    byte[] dataBytes = GetBytes(data);
    byte[] encryptedData;
    using (RSACryptoServiceProvider csp = new RSACryptoServiceProvider())
    {
        csp.ImportParameters(publicKey);
        encryptedData = csp.Encrypt(dataBytes, false);
    }
    return GetBase64String(encryptedData);
}

• Encrypts data with XML type key sent as string

public static string EncryptWithXMLKey(string publicKey, string data)
{
    byte[] dataBytes = GetBytes(data);
    byte[] encryptedData;
    using (RSACryptoServiceProvider csp = new RSACryptoServiceProvider())
    {
        csp.FromXmlString(publicKey);
        encryptedData = csp.Encrypt(dataBytes, false);
    }
    return GetBase64String(encryptedData);
}

GetBytes() method

private static byte[] GetBytes(string data)
{
    return byteConverter.GetBytes(data);
}

GetBase64String() method

private static string GetBase64String(byte[] encryptedData)
{
    return Convert.ToBase64String(encryptedData);
}

byteConverter

private static UnicodeEncoding byteConverter = new UnicodeEncoding();

Decrypt

public static class Decrypt {...}

• Decrypts the data with the key of type RSAParameters sent

public static string DecryptWithKey(RSAParameters privateKey, string encryptedData)
{
    byte[] dataBytes = GetBytes(encryptedData);
    byte[] decryptedData;
    using (RSACryptoServiceProvider csp = new RSACryptoServiceProvider())
    {
        csp.ImportParameters(privateKey);
        decryptedData = csp.Decrypt(dataBytes, false);
    }
    return GetString(decryptedData);
}

• Decrypts data with XML type key sent as string

public static string DecryptWithXMLKey(string privateKey, string encryptedData)
{
    byte[] dataBytes = GetBytes(encryptedData);
    byte[] decryptedData;
    using (RSACryptoServiceProvider csp = new RSACryptoServiceProvider())
    {
        csp.FromXmlString(privateKey);
        decryptedData = csp.Decrypt(dataBytes, false);
    }
    return GetString(decryptedData);
}

GetString() method

private static string GetString(byte[] decryptedData)
{
    return byteConverter.GetString(decryptedData);
}

GetBytes() method

private static byte[] GetBytes(string encryptedData)
{
    return Convert.FromBase64String(encryptedData);
}

byteConverter

private static UnicodeEncoding byteConverter = new UnicodeEncoding();