RSACryptoServiceProvider.Encrypt Method

Definition

Encrypts data with the RSA algorithm.

Overloads

Encrypt(Byte[], Boolean)

Encrypts data with the RSA algorithm.

Encrypt(Byte[], RSAEncryptionPadding)

Encrypts data with the RSA algorithm using the specified padding.

Encrypt(Byte[], Boolean)

Encrypts data with the RSA algorithm.

public:
 cli::array <System::Byte> ^ Encrypt(cli::array <System::Byte> ^ rgb, bool fOAEP);
public byte[] Encrypt (byte[] rgb, bool fOAEP);
override this.Encrypt : byte[] * bool -> byte[]
member this.Encrypt : byte[] * bool -> byte[]
Public Function Encrypt (rgb As Byte(), fOAEP As Boolean) As Byte()

Parameters

rgb
Byte[]

The data to be encrypted.

fOAEP
Boolean

true to perform direct RSA encryption using OAEP padding (only available on a computer running Windows XP or later); otherwise, false to use PKCS#1 v1.5 padding.

Returns

Byte[]

The encrypted data.

Exceptions

The cryptographic service provider (CSP) cannot be acquired.

-or-

The length of the rgb parameter is greater than the maximum allowed length.

rgb is null.

Examples

The following code example initializes an RSACryptoServiceProvider object to the value of a public key (sent by another party), generates a session key using the Aes algorithm, and then encrypts the session key using the RSACryptoServiceProvider object. Using this scheme, the session key could be sent back to the owner of the private RSA key and the two parties could use the session key to exchange encrypted data.

#using <System.dll>

using namespace System;
using namespace System::Security::Cryptography;
int main()
{
   try
   {
      
      //initialze the Byte arrays to the public key information.
      array<Byte>^PublicKey = {214,46,220,83,160,73,40,39,201,155,19,202,3,11,191,178,56,74,90,36,248,103,18,144,170,163,145,87,54,61,34,220,222,207,137,149,173,14,92,120,206,222,158,28,40,24,30,16,175,108,128,35,230,118,40,121,113,125,216,130,11,24,90,48,194,240,105,44,76,34,57,249,228,125,80,38,9,136,29,117,207,139,168,181,85,137,126,10,126,242,120,247,121,8,100,12,201,171,38,226,193,180,190,117,177,87,143,242,213,11,44,180,113,93,106,99,179,68,175,211,164,116,64,148,226,254,172,147};
      array<Byte>^Exponent = {1,0,1};
      
      //Values to store encrypted symmetric keys.
      array<Byte>^EncryptedSymmetricKey;
      array<Byte>^EncryptedSymmetricIV;
      
      //Create a new instance of RSACryptoServiceProvider.
      RSACryptoServiceProvider^ RSA = gcnew RSACryptoServiceProvider;
      
      //Create a new instance of RSAParameters.
      RSAParameters RSAKeyInfo;
      
      //Set RSAKeyInfo to the public key values. 
      RSAKeyInfo.Modulus = PublicKey;
      RSAKeyInfo.Exponent = Exponent;
      
      //Import key parameters into RSA.
      RSA->ImportParameters( RSAKeyInfo );
      
      //Create a new instance of the Aes class.
      Aes^ aes = Aes::Create();
      
      //Encrypt the symmetric key and IV.
      EncryptedSymmetricKey = RSA->Encrypt( aes->Key, false );
      EncryptedSymmetricIV = RSA->Encrypt( aes->IV, false );
      Console::WriteLine( "Aes Key and IV have been encrypted with RSACryptoServiceProvider." );
   }
   catch ( CryptographicException^ e ) 
   {
      
      //Catch and display a CryptographicException  
      //to the console.
      Console::WriteLine( e->Message );
   }

}
using System;
using System.Security.Cryptography;

class RSACSPSample
{

    static void Main()
    {
        try
        {		//initialze the byte arrays to the public key information.
            byte[] PublicKey = {214,46,220,83,160,73,40,39,201,155,19,202,3,11,191,178,56,
                                   74,90,36,248,103,18,144,170,163,145,87,54,61,34,220,222,
                                   207,137,149,173,14,92,120,206,222,158,28,40,24,30,16,175,
                                   108,128,35,230,118,40,121,113,125,216,130,11,24,90,48,194,
                                   240,105,44,76,34,57,249,228,125,80,38,9,136,29,117,207,139,
                                   168,181,85,137,126,10,126,242,120,247,121,8,100,12,201,171,
                                   38,226,193,180,190,117,177,87,143,242,213,11,44,180,113,93,
                                   106,99,179,68,175,211,164,116,64,148,226,254,172,147};

            byte[] Exponent = {1,0,1};
      
            //Values to store encrypted symmetric keys.
            byte[] EncryptedSymmetricKey;
            byte[] EncryptedSymmetricIV;

            //Create a new instance of RSACryptoServiceProvider.
            RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();

            //Create a new instance of RSAParameters.
            RSAParameters RSAKeyInfo = new RSAParameters();

            //Set RSAKeyInfo to the public key values. 
            RSAKeyInfo.Modulus = PublicKey;
            RSAKeyInfo.Exponent = Exponent;

            //Import key parameters into RSA.
            RSA.ImportParameters(RSAKeyInfo);

            //Create a new instance of the Aes class.
            Aes aes = Aes.Create();

            //Encrypt the symmetric key and IV.
            EncryptedSymmetricKey = RSA.Encrypt(aes.Key, false);
            EncryptedSymmetricIV = RSA.Encrypt(aes.IV, false);

            Console.WriteLine("Aes Key and IV have been encrypted with RSACryptoServiceProvider."); 
        }
        //Catch and display a CryptographicException  
        //to the console.
        catch(CryptographicException e)
        {
            Console.WriteLine(e.Message);
        }
    }
}
Imports System.Security.Cryptography

Class RSACSPSample

    Shared Sub Main()
        Try
            'initialze the byte arrays to the public key information.
            Dim PublicKey As Byte() = {214, 46, 220, 83, 160, 73, 40, 39, 201, 155, 19, 202, 3, 11, 191, 178, 56, 74, 90, 36, 248, 103, 18, 144, 170, 163, 145, 87, 54, 61, 34, 220, 222, 207, 137, 149, 173, 14, 92, 120, 206, 222, 158, 28, 40, 24, 30, 16, 175, 108, 128, 35, 230, 118, 40, 121, 113, 125, 216, 130, 11, 24, 90, 48, 194, 240, 105, 44, 76, 34, 57, 249, 228, 125, 80, 38, 9, 136, 29, 117, 207, 139, 168, 181, 85, 137, 126, 10, 126, 242, 120, 247, 121, 8, 100, 12, 201, 171, 38, 226, 193, 180, 190, 117, 177, 87, 143, 242, 213, 11, 44, 180, 113, 93, 106, 99, 179, 68, 175, 211, 164, 116, 64, 148, 226, 254, 172, 147}

            Dim Exponent As Byte() = {1, 0, 1}

            'Values to store encrypted symmetric keys.
            Dim EncryptedSymmetricKey() As Byte
            Dim EncryptedSymmetricIV() As Byte

            'Create a new instance of RSACryptoServiceProvider.
            Dim RSA As New RSACryptoServiceProvider()

            'Create a new instance of RSAParameters.
            Dim RSAKeyInfo As New RSAParameters()

            'Set RSAKeyInfo to the public key values. 
            RSAKeyInfo.Modulus = PublicKey
            RSAKeyInfo.Exponent = Exponent

            'Import key parameters into RSA.
            RSA.ImportParameters(RSAKeyInfo)

            'Create a new instance of the Aes class.
            Dim aes As Aes = Aes.Create()

            'Encrypt the symmetric key and IV.
            EncryptedSymmetricKey = RSA.Encrypt(aes.Key, False)
            EncryptedSymmetricIV = RSA.Encrypt(aes.IV, False)

            Console.WriteLine("Aes Key and IV have been encrypted with RSA.")

            'Catch and display a CryptographicException  
            'to the console.
        Catch e As CryptographicException
            Console.WriteLine(e.Message)
        End Try
    End Sub
End Class

Remarks

The following table describes the padding supported by different versions of Microsoft Windows and the maximum length of rgb allowed by the different combinations of operating systems and padding.

Padding Maximum Length of rgb Parameter
OAEP padding (PKCS#1 v2) Modulus size -2 -2*hLen, where hLen is the size of the hash.
Direct Encryption (PKCS#1 v1.5) Modulus size - 11. (11 bytes is the minimum padding possible.)

Use Decrypt to decrypt the results of this method.

See also

Applies to

Encrypt(Byte[], RSAEncryptionPadding)

Encrypts data with the RSA algorithm using the specified padding.

public:
 override cli::array <System::Byte> ^ Encrypt(cli::array <System::Byte> ^ data, System::Security::Cryptography::RSAEncryptionPadding ^ padding);
public override byte[] Encrypt (byte[] data, System.Security.Cryptography.RSAEncryptionPadding padding);
override this.Encrypt : byte[] * System.Security.Cryptography.RSAEncryptionPadding -> byte[]
Public Overrides Function Encrypt (data As Byte(), padding As RSAEncryptionPadding) As Byte()

Parameters

data
Byte[]

The data to encrypt.

padding
RSAEncryptionPadding

The padding.

Returns

Byte[]

The encrypted data.

Exceptions

data is null.

-or-

padding is null.

The padding mode is not supported.

Remarks

padding must be either RSAEncryptionPadding.Pkcs1 or RSAEncryptionPadding.OaepSHA1.

Applies to