Aes Class

Definition

Represents the abstract base class from which all implementations of the Advanced Encryption Standard (AES) must inherit.

public ref class Aes abstract : System::Security::Cryptography::SymmetricAlgorithm
[System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
public abstract class Aes : System.Security.Cryptography.SymmetricAlgorithm
public abstract class Aes : System.Security.Cryptography.SymmetricAlgorithm
[<System.Runtime.Versioning.UnsupportedOSPlatform("browser")>]
type Aes = class
    inherit SymmetricAlgorithm
type Aes = class
    inherit SymmetricAlgorithm
Public MustInherit Class Aes
Inherits SymmetricAlgorithm
Inheritance
Derived
Attributes

Examples

The following example demonstrates how to encrypt and decrypt sample data by using the Aes class.

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

namespace Aes_Example
{
    class AesExample
    {
        public static void Main()
        {
            string original = "Here is some data to encrypt!";

            // Create a new instance of the Aes
            // class.  This generates a new key and initialization
            // vector (IV).
            using (Aes myAes = Aes.Create())
            {

                // Encrypt the string to an array of bytes.
                byte[] encrypted = EncryptStringToBytes_Aes(original, myAes.Key, myAes.IV);

                // Decrypt the bytes to a string.
                string roundtrip = DecryptStringFromBytes_Aes(encrypted, myAes.Key, myAes.IV);

                //Display the original data and the decrypted data.
                Console.WriteLine("Original:   {0}", original);
                Console.WriteLine("Round Trip: {0}", roundtrip);
            }
        }
        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 Aes object
            // with the specified key and IV.
            using (Aes aesAlg = Aes.Create())
            {
                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;
        }

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

            // Declare the string used to hold
            // the decrypted text.
            string plaintext = null;

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

                // Create a decryptor to perform the stream transform.
                ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);

                // Create the streams used for decryption.
                using (MemoryStream msDecrypt = new MemoryStream(cipherText))
                {
                    using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                    {
                        using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                        {

                            // Read the decrypted bytes from the decrypting stream
                            // and place them in a string.
                            plaintext = srDecrypt.ReadToEnd();
                        }
                    }
                }
            }

            return plaintext;
        }
    }
}
Imports System.IO
Imports System.Security.Cryptography



Class AesExample

    Public Shared Sub Main()
        Dim original As String = "Here is some data to encrypt!"

        ' Create a new instance of the Aes
        ' class.  This generates a new key and initialization 
        ' vector (IV).
        Using myAes As Aes = Aes.Create()
            ' Encrypt the string to an array of bytes.
            Dim encrypted As Byte() = EncryptStringToBytes_Aes(original, myAes.Key, myAes.IV)

            ' Decrypt the bytes to a string.
            Dim roundtrip As String = DecryptStringFromBytes_Aes(encrypted, myAes.Key, myAes.IV)

            'Display the original data and the decrypted data.
            Console.WriteLine("Original:   {0}", original)
            Console.WriteLine("Round Trip: {0}", roundtrip)
        End Using
    End Sub

    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 Aes object
        ' with the specified key and IV.
        Using aesAlg As Aes = Aes.Create()

            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.
            Using 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
        End Using

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

    End Function 'EncryptStringToBytes_Aes

    Shared Function DecryptStringFromBytes_Aes(ByVal cipherText() As Byte, ByVal Key() As Byte, ByVal IV() As Byte) As String
        ' Check arguments.
        If cipherText Is Nothing OrElse cipherText.Length <= 0 Then
            Throw New ArgumentNullException("cipherText")
        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
        ' Declare the string used to hold
        ' the decrypted text.
        Dim plaintext As String = Nothing

        ' Create an Aes object
        ' with the specified key and IV.
        Using aesAlg As Aes = Aes.Create()
            aesAlg.Key = Key
            aesAlg.IV = IV

            ' Create a decryptor to perform the stream transform.
            Dim decryptor As ICryptoTransform = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV)

            ' Create the streams used for decryption.
            Using msDecrypt As New MemoryStream(cipherText)

                Using csDecrypt As New CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)

                    Using srDecrypt As New StreamReader(csDecrypt)


                        ' Read the decrypted bytes from the decrypting stream
                        ' and place them in a string.
                        plaintext = srDecrypt.ReadToEnd()
                    End Using
                End Using
            End Using
        End Using

        Return plaintext

    End Function 'DecryptStringFromBytes_Aes 
End Class
open System
open System.IO
open System.Security.Cryptography

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 Aes object
    // with the specified key and IV.
    use aesAlg = Aes.Create()
    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()

let decryptStringFromBytes_Aes (cipherText : byte[], key : byte[], iv : byte[]) : string =

    // Check arguments.
    if (isNull cipherText || cipherText.Length <= 0) then nullArg "cipherText"
    if (isNull key || key.Length <= 0) then nullArg "key"
    if (isNull iv || iv.Length <= 0) then nullArg "iv"

    // Create an Aes object
    // with the specified key and IV.
    use aesAlg = Aes.Create()
    aesAlg.Key <- key
    aesAlg.IV <- iv

    // Create a decryptor to perform the stream transform.
    let decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV)

    // Create the streams used for decryption.
    use msDecrypt = new MemoryStream(cipherText)
    use csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)
    use srDecrypt = new StreamReader(csDecrypt)

    // Read the decrypted bytes from the decrypting stream
    // and return the resulting string.
    srDecrypt.ReadToEnd()

[<EntryPoint>]
let main argv = 

    let original = "Here is some data to encrypt!"

    // Create a new instance of the Aes
    // class.  This generates a new key and initialization 
    // vector (IV).
    use myAes = Aes.Create()

    // Encrypt the string to an array of bytes.
    let encrypted = encryptStringToBytes_Aes(original, myAes.Key, myAes.IV)

    // Decrypt the bytes to a string.
    let roundtrip = decryptStringFromBytes_Aes(encrypted, myAes.Key, myAes.IV)

    //Display the original data and the decrypted data.
    Console.WriteLine("Original:   {0}", original)
    Console.WriteLine("Round Trip: {0}", roundtrip)
    0

Constructors

Aes()

Initializes a new instance of the Aes class.

Fields

BlockSizeValue

Represents the block size, in bits, of the cryptographic operation.

(Inherited from SymmetricAlgorithm)
FeedbackSizeValue

Represents the feedback size, in bits, of the cryptographic operation.

(Inherited from SymmetricAlgorithm)
IVValue

Represents the initialization vector (IV) for the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
KeySizeValue

Represents the size, in bits, of the secret key used by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
KeyValue

Represents the secret key for the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
LegalBlockSizesValue

Specifies the block sizes, in bits, that are supported by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
LegalKeySizesValue

Specifies the key sizes, in bits, that are supported by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
ModeValue

Represents the cipher mode used in the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
PaddingValue

Represents the padding mode used in the symmetric algorithm.

(Inherited from SymmetricAlgorithm)

Properties

BlockSize

Gets or sets the block size, in bits, of the cryptographic operation.

(Inherited from SymmetricAlgorithm)
FeedbackSize

Gets or sets the feedback size, in bits, of the cryptographic operation for the Cipher Feedback (CFB) and Output Feedback (OFB) cipher modes.

(Inherited from SymmetricAlgorithm)
IV

Gets or sets the initialization vector (IV) for the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
Key

Gets or sets the secret key for the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
KeySize

Gets or sets the size, in bits, of the secret key used by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
LegalBlockSizes

Gets the block sizes, in bits, that are supported by the symmetric algorithm.

LegalBlockSizes

Gets the block sizes, in bits, that are supported by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
LegalKeySizes

Gets the key sizes, in bits, that are supported by the symmetric algorithm.

LegalKeySizes

Gets the key sizes, in bits, that are supported by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
Mode

Gets or sets the mode for operation of the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
Padding

Gets or sets the padding mode used in the symmetric algorithm.

(Inherited from SymmetricAlgorithm)

Methods

Clear()

Releases all resources used by the SymmetricAlgorithm class.

(Inherited from SymmetricAlgorithm)
Create()

Creates a cryptographic object that is used to perform the symmetric algorithm.

Create(String)
Obsolete.

Creates a cryptographic object that specifies the implementation of AES to use to perform the symmetric algorithm.

CreateDecryptor()

Creates a symmetric decryptor object with the current Key property and initialization vector (IV).

(Inherited from SymmetricAlgorithm)
CreateDecryptor(Byte[], Byte[])

When overridden in a derived class, creates a symmetric decryptor object with the specified Key property and initialization vector (IV).

(Inherited from SymmetricAlgorithm)
CreateEncryptor()

Creates a symmetric encryptor object with the current Key property and initialization vector (IV).

(Inherited from SymmetricAlgorithm)
CreateEncryptor(Byte[], Byte[])

When overridden in a derived class, creates a symmetric encryptor object with the specified Key property and initialization vector (IV).

(Inherited from SymmetricAlgorithm)
DecryptCbc(Byte[], Byte[], PaddingMode)

Decrypts data using CBC mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
DecryptCbc(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, PaddingMode)

Decrypts data using CBC mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
DecryptCbc(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode)

Decrypts data into the specified buffer, using CBC mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
DecryptCfb(Byte[], Byte[], PaddingMode, Int32)

Decrypts data using CFB mode with the specified padding mode and feedback size.

(Inherited from SymmetricAlgorithm)
DecryptCfb(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, PaddingMode, Int32)

Decrypts data using CFB mode with the specified padding mode and feedback size.

(Inherited from SymmetricAlgorithm)
DecryptCfb(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)

Decrypts data into the specified buffer, using CFB mode with the specified padding mode and feedback size.

(Inherited from SymmetricAlgorithm)
DecryptEcb(Byte[], PaddingMode)

Decrypts data using ECB mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
DecryptEcb(ReadOnlySpan<Byte>, PaddingMode)

Decrypts data using ECB mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
DecryptEcb(ReadOnlySpan<Byte>, Span<Byte>, PaddingMode)

Decrypts data into the specified buffer, using ECB mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
Dispose()

Releases all resources used by the current instance of the SymmetricAlgorithm class.

(Inherited from SymmetricAlgorithm)
Dispose(Boolean)

Releases the unmanaged resources used by the SymmetricAlgorithm and optionally releases the managed resources.

(Inherited from SymmetricAlgorithm)
EncryptCbc(Byte[], Byte[], PaddingMode)

Encrypts data using CBC mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
EncryptCbc(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, PaddingMode)

Encrypts data using CBC mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
EncryptCbc(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode)

Encrypts data into the specified buffer, using CBC mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
EncryptCfb(Byte[], Byte[], PaddingMode, Int32)

Encrypts data using CFB mode with the specified padding mode and feedback size.

(Inherited from SymmetricAlgorithm)
EncryptCfb(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, PaddingMode, Int32)

Encrypts data using CFB mode with the specified padding mode and feedback size.

(Inherited from SymmetricAlgorithm)
EncryptCfb(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)

Encrypts data into the specified buffer, using CFB mode with the specified padding mode and feedback size.

(Inherited from SymmetricAlgorithm)
EncryptEcb(Byte[], PaddingMode)

Encrypts data using ECB mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
EncryptEcb(ReadOnlySpan<Byte>, PaddingMode)

Encrypts data using ECB mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
EncryptEcb(ReadOnlySpan<Byte>, Span<Byte>, PaddingMode)

Encrypts data into the specified buffer, using ECB mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GenerateIV()

When overridden in a derived class, generates a random initialization vector (IV) to use for the algorithm.

(Inherited from SymmetricAlgorithm)
GenerateKey()

When overridden in a derived class, generates a random key (Key) to use for the algorithm.

(Inherited from SymmetricAlgorithm)
GetCiphertextLengthCbc(Int32, PaddingMode)

Gets the length of a ciphertext with a given padding mode and plaintext length in CBC mode.

(Inherited from SymmetricAlgorithm)
GetCiphertextLengthCfb(Int32, PaddingMode, Int32)

Gets the length of a ciphertext with a given padding mode and plaintext length in CFB mode.

(Inherited from SymmetricAlgorithm)
GetCiphertextLengthEcb(Int32, PaddingMode)

Gets the length of a ciphertext with a given padding mode and plaintext length in ECB mode.

(Inherited from SymmetricAlgorithm)
GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetType()

Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
ToString()

Returns a string that represents the current object.

(Inherited from Object)
TryDecryptCbc(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, Int32, PaddingMode)

Attempts to decrypt data into the specified buffer, using CBC mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
TryDecryptCbcCore(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)

When overridden in a derived class, attempts to decrypt data into the specified buffer, using CBC mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
TryDecryptCfb(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, Int32, PaddingMode, Int32)

Attempts to decrypt data into the specified buffer, using CFB mode with the specified padding mode and feedback size.

(Inherited from SymmetricAlgorithm)
TryDecryptCfbCore(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32, Int32)

When overridden in a derived class, attempts to decrypt data into the specified buffer, using CFB mode with the specified padding mode and feedback size.

(Inherited from SymmetricAlgorithm)
TryDecryptEcb(ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)

Attempts to decrypt data into the specified buffer, using ECB mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
TryDecryptEcbCore(ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)

When overridden in a derived class, attempts to decrypt data into the specified buffer, using ECB mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
TryEncryptCbc(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, Int32, PaddingMode)

Attempts to encrypt data into the specified buffer, using CBC mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
TryEncryptCbcCore(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)

When overridden in a derived class, attempts to encrypt data into the specified buffer, using CBC mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
TryEncryptCfb(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, Int32, PaddingMode, Int32)

Attempts to encrypt data into the specified buffer, using CFB mode with the specified padding mode and feedback size.

(Inherited from SymmetricAlgorithm)
TryEncryptCfbCore(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32, Int32)

When overridden in a derived class, attempts to encrypt data into the specified buffer, using CFB mode with the specified padding mode and feedback size.

(Inherited from SymmetricAlgorithm)
TryEncryptEcb(ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)

Attempts to encrypt data into the specified buffer, using ECB mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
TryEncryptEcbCore(ReadOnlySpan<Byte>, Span<Byte>, PaddingMode, Int32)

When overridden in a derived class, attempts to encrypt data into the specified buffer, using ECB mode with the specified padding mode.

(Inherited from SymmetricAlgorithm)
ValidKeySize(Int32)

Determines whether the specified key size is valid for the current algorithm.

(Inherited from SymmetricAlgorithm)

Explicit Interface Implementations

IDisposable.Dispose()

This API supports the product infrastructure and is not intended to be used directly from your code.

Releases the unmanaged resources used by the SymmetricAlgorithm and optionally releases the managed resources.

(Inherited from SymmetricAlgorithm)

Applies to