AesCryptoServiceProvider.CreateEncryptor Method

Definition

Namespace:

System.Security.Cryptography

Assembly:

System.Security.Cryptography.dll

Creates a symmetric AES encryptor object.

Overloads

CreateEncryptor()	Creates a symmetric AES encryptor object using the current key and initialization vector (IV).
CreateEncryptor(Byte[], Byte[])	Creates a symmetric encryptor object using the specified key and initialization vector (IV).

CreateEncryptor()

Source:

AesCryptoServiceProvider.cs

Creates a symmetric AES encryptor object using the current key and initialization vector (IV).

public:
 override System::Security::Cryptography::ICryptoTransform ^ CreateEncryptor();

public override System.Security.Cryptography.ICryptoTransform CreateEncryptor ();

override this.CreateEncryptor : unit -> System.Security.Cryptography.ICryptoTransform

Public Overrides Function CreateEncryptor () As ICryptoTransform

Returns

ICryptoTransform

A symmetric AES encryptor object.

CreateEncryptor(Byte[], Byte[])

Source:

AesCryptoServiceProvider.cs

Creates a symmetric encryptor object using the specified key and initialization vector (IV).

public:
 override System::Security::Cryptography::ICryptoTransform ^ CreateEncryptor(cli::array <System::Byte> ^ rgbKey, cli::array <System::Byte> ^ rgbIV);

public override System.Security.Cryptography.ICryptoTransform CreateEncryptor (byte[] rgbKey, byte[]? rgbIV);

override this.CreateEncryptor : byte[] * byte[] -> System.Security.Cryptography.ICryptoTransform

Public Overrides Function CreateEncryptor (rgbKey As Byte(), rgbIV As Byte()) As ICryptoTransform

Parameters

rgbKey

Byte[]

The secret key to use for the symmetric algorithm.

rgbIV

Byte[]

The initialization vector to use for the symmetric algorithm.

Returns

ICryptoTransform

A symmetric AES encryptor object.

Exceptions

ArgumentNullException

The key or iv parameter is null.

ArgumentException

key is invalid.

Examples

The following example shows how to use the AesCryptoServiceProvider.CreateEncryptor method to encrypt a message. This code example is part of a larger example provided for the AesCryptoServiceProvider class.

static byte[] EncryptStringToBytes_Aes(string plainText, byte[] Key, byte[] IV)
{
    // Check arguments.
    if (plainText == null || plainText.Length <= 0)
        throw new ArgumentNullException("plainText");
    if (Key == null || Key.Length <= 0)
        throw new ArgumentNullException("Key");
    if (IV == null || IV.Length <= 0)
        throw new ArgumentNullException("IV");
    byte[] encrypted;

    // Create an AesCryptoServiceProvider object
    // with the specified key and IV.
    using (AesCryptoServiceProvider aesAlg = new AesCryptoServiceProvider())
    {
        aesAlg.Key = Key;
        aesAlg.IV = IV;

        // Create an encryptor to perform the stream transform.
        ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);

        // Create the streams used for encryption.
        using (MemoryStream msEncrypt = new MemoryStream())
        {
            using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
            {
                using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                {
                    //Write all data to the stream.
                    swEncrypt.Write(plainText);
                }
                encrypted = msEncrypt.ToArray();
            }
        }
    }

    // Return the encrypted bytes from the memory stream.
    return encrypted;
}

Shared Function EncryptStringToBytes_Aes(ByVal plainText As String, ByVal Key() As Byte, ByVal IV() As Byte) As Byte() 
    ' Check arguments.
    If plainText Is Nothing OrElse plainText.Length <= 0 Then
        Throw New ArgumentNullException("plainText")
    End If
    If Key Is Nothing OrElse Key.Length <= 0 Then
        Throw New ArgumentNullException("Key")
    End If
    If IV Is Nothing OrElse IV.Length <= 0 Then
        Throw New ArgumentNullException("IV")
    End If
    Dim encrypted() As Byte
    
    ' Create an AesCryptoServiceProvider object
    ' with the specified key and IV.
    Using aesAlg As New AesCryptoServiceProvider()

        aesAlg.Key = Key
        aesAlg.IV = IV

        ' Create an encryptor to perform the stream transform.
        Dim encryptor As ICryptoTransform = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV)

        ' Create the streams used for encryption.
        Dim msEncrypt As New MemoryStream()
        Using csEncrypt As New CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)
            Using swEncrypt As New StreamWriter(csEncrypt)
                'Write all data to the stream.
                swEncrypt.Write(plainText)
            End Using
            encrypted = msEncrypt.ToArray()

        End Using
    End Using

    ' Return the encrypted bytes from the memory stream.
    Return encrypted

End Function 'EncryptStringToBytes_Aes

let encryptStringToBytes_Aes (plainText: string, key : byte[], iv : byte[]) : byte[] =

    // Check arguments.
    if (isNull plainText || plainText.Length <= 0) then nullArg "plainText"
    if (isNull key || key.Length <= 0) then nullArg "key"
    if (isNull iv || iv.Length <= 0) then nullArg "iv"
    
    // Create an AesCryptoServiceProvider object
    // with the specified key and IV.
    use aesAlg = new AesCryptoServiceProvider()
    aesAlg.Key <- key
    aesAlg.IV <- iv

    // Create an encryptor to perform the stream transform.
    let encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV)

    // Create the streams used for encryption.
    use msEncrypt = new MemoryStream()
    use csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)
    use swEncrypt = new StreamWriter(csEncrypt)
    
    //Write all data to the stream.
    swEncrypt.Write(plainText)
    swEncrypt.Flush()
    
    // Return the encrypted bytes from the memory stream.
    msEncrypt.ToArray()

Remarks

See the code examples in the LegalKeySizes and LegalBlockSizes properties to determine the size of the key and iv parameters.