RC2.Create Method

Definition

Namespace:

System.Security.Cryptography

Assemblies:

netstandard.dll, System.Security.Cryptography.dll

Creates an instance of a cryptographic object to perform the RC2 algorithm.

Overloads

Create()	Creates an instance of a cryptographic object to perform the RC2 algorithm.
Create(String)	Obsolete. Creates an instance of a cryptographic object to perform the specified implementation of the RC2 algorithm.

Create()

Source:

RC2.cs

Creates an instance of a cryptographic object to perform the RC2 algorithm.

C#

[System.Runtime.Versioning.UnsupportedOSPlatform("android")]
[System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
public static System.Security.Cryptography.RC2 Create();

Returns

RC2

An instance of a cryptographic object.

Attributes

UnsupportedOSPlatformAttribute

Exceptions

TargetInvocationException

The algorithm was used with Federal Information Processing Standards (FIPS) mode enabled, but is not FIPS compatible.

Examples

The following example shows how to create and use an RC2 object to encrypt and decrypt data in a file.

C#

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

class RC2Sample
{
    static void Main()
    {
        try
        {
            byte[] key;
            byte[] iv;

            // Create a new RC2 object to generate a random key
            // and initialization vector (IV).
            using (RC2 rc2 = RC2.Create())
            {
                key = rc2.Key;
                iv = rc2.IV;
            }

            // Create a string to encrypt.
            string original = "Here is some data to encrypt.";
            // The name/path of the file to write.
            string filename = "CText.enc";

            // Encrypt the string to a file.
            EncryptTextToFile(original, filename, key, iv);

            // Decrypt the file back to a string.
            string decrypted = DecryptTextFromFile(filename, key, iv);

            // Display the decrypted string to the console.
            Console.WriteLine(decrypted);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }

    public static void EncryptTextToFile(string text, string path, byte[] key, byte[] iv)
    {
        try
        {
            // Create or open the specified file.
            using (FileStream fStream = File.Open(path, FileMode.Create))
            // Create a new RC2 object.
            using (RC2 rc2 = RC2.Create())
            // Create an RC2 encryptor from the key and IV
            using (ICryptoTransform encryptor = rc2.CreateEncryptor(key, iv))
            // Create a CryptoStream using the FileStream and encryptor
            using (var cStream = new CryptoStream(fStream, encryptor, CryptoStreamMode.Write))
            {
                // Convert the provided string to a byte array.
                byte[] toEncrypt = Encoding.UTF8.GetBytes(text);

                // Write the byte array to the crypto stream.
                cStream.Write(toEncrypt, 0, toEncrypt.Length);
            }
        }
        catch (CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            throw;
        }
    }

    public static string DecryptTextFromFile(string path, byte[] key, byte[] iv)
    {
        try
        {
            // Open the specified file
            using (FileStream fStream = File.OpenRead(path))
            // Create a new RC2 object.
            using (RC2 rc2 = RC2.Create())
            // Create an RC2 decryptor from the key and IV
            using (ICryptoTransform decryptor = rc2.CreateDecryptor(key, iv))
            // Create a CryptoStream using the FileStream and decryptor
            using (var cStream = new CryptoStream(fStream, decryptor, CryptoStreamMode.Read))
            // Create a StreamReader to turn the bytes back into text
            using (StreamReader reader = new StreamReader(cStream, Encoding.UTF8))
            {
                // Read back all of the text from the StreamReader, which receives
                // the decrypted bytes from the CryptoStream, which receives the
                // encrypted bytes from the FileStream.
                return reader.ReadToEnd();
            }
        }
        catch (CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            throw;
        }
    }
}

The following example shows how to create and use an RC2 object to encrypt and decrypt data in memory.

C#

using System;
using System.Security.Cryptography;
using System.Text;
using System.IO;

class RC2Sample2
{
    static void Main()
    {
        try
        {
            byte[] key;
            byte[] iv;

            // Create a new RC2 object to generate a random key
            // and initialization vector (IV).
            using (RC2 rc2 = RC2.Create())
            {
                key = rc2.Key;
                iv = rc2.IV;
            }

            // Create a string to encrypt.
            string original = "Here is some data to encrypt.";

            // Encrypt the string to an in-memory buffer.
            byte[] encrypted = EncryptTextToMemory(original, key, iv);

            // Decrypt the buffer back to a string.
            string decrypted = DecryptTextFromMemory(encrypted, key, iv);

            // Display the decrypted string to the console.
            Console.WriteLine(decrypted);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }

    public static byte[] EncryptTextToMemory(string text, byte[] key, byte[] iv)
    {
        try
        {
            // Create a MemoryStream.
            using (MemoryStream mStream = new MemoryStream())
            {
                // Create a new RC2 object.
                using (RC2 rc2 = RC2.Create())
                // Create an RC2 encryptor from the key and IV
                using (ICryptoTransform encryptor = rc2.CreateEncryptor(key, iv))
                // Create a CryptoStream using the MemoryStream and encryptor
                using (var cStream = new CryptoStream(mStream, encryptor, CryptoStreamMode.Write))
                {
                    // Convert the provided string to a byte array.
                    byte[] toEncrypt = Encoding.UTF8.GetBytes(text);

                    // Write the byte array to the crypto stream and flush it.
                    cStream.Write(toEncrypt, 0, toEncrypt.Length);

                    // Ending the using statement for the CryptoStream completes the encryption.
                }

                // Get an array of bytes from the MemoryStream that holds the encrypted data.
                byte[] ret = mStream.ToArray();

                // Return the encrypted buffer.
                return ret;
            }
        }
        catch (CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            throw;
        }
    }

    public static string DecryptTextFromMemory(byte[] encrypted, byte[] key, byte[] iv)
    {
        try
        {
            // Create a buffer to hold the decrypted data.
            // RC2-encrypted data will always be slightly bigger than the decrypted data.
            byte[] decrypted = new byte[encrypted.Length];
            int offset = 0;

            // Create a new MemoryStream using the provided array of encrypted data.
            using (MemoryStream mStream = new MemoryStream(encrypted))
            {
                // Create a new RC2 object.
                using (RC2 rc2 = RC2.Create())
                // Create an RC2 decryptor from the key and IV
                using (ICryptoTransform decryptor = rc2.CreateDecryptor(key, iv))
                // Create a CryptoStream using the MemoryStream and decryptor
                using (var cStream = new CryptoStream(mStream, decryptor, CryptoStreamMode.Read))
                {
                    // Keep reading from the CryptoStream until it finishes (returns 0).
                    int read = 1;

                    while (read > 0)
                    {
                        read = cStream.Read(decrypted, offset, decrypted.Length - offset);
                        offset += read;
                    }
                }
            }

            // Convert the buffer into a string and return it.
            return Encoding.UTF8.GetString(decrypted, 0, offset);
        }
        catch (CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            throw;
        }
    }
}

Remarks

Use this method to create an instance of the RC2 class that you can use to encrypt and decrypt data.

See also

• Cryptographic Services

Create(String)

Source:

RC2.cs

Caution

Cryptographic factory methods accepting an algorithm name are obsolete. Use the parameterless Create factory method on the algorithm type instead.

Creates an instance of a cryptographic object to perform the specified implementation of the RC2 algorithm.

C#

[System.Obsolete("Cryptographic factory methods accepting an algorithm name are obsolete. Use the parameterless Create factory method on the algorithm type instead.", DiagnosticId="SYSLIB0045", UrlFormat="https://aka.ms/dotnet-warnings/{0}")]
public static System.Security.Cryptography.RC2? Create(string AlgName);

Parameters

AlgName

String

The name of the specific implementation of RC2 to use.

Returns

RC2

An instance of a cryptographic object.

Attributes

ObsoleteAttribute

Exceptions

TargetInvocationException

The algorithm described by the algName parameter was used with Federal Information Processing Standards (FIPS) mode enabled, but is not FIPS compatible.

See also

• Cryptographic Services