ARC4 Encryption (ARCFOUR)

Demonstrates simple ARC4 encryption to match some simple test vectors published by Wikipedia. ARC4 is a fast stream cipher supporting key lengths from 8 to 2048 bits (i.e. from 1 to 256 bytes). It is not a block cipher, so there is no padding, no modes, and no initialization vector.

Download Chilkat Crypt ActiveX

CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @crypt int
    EXEC @hr = sp_OACreate 'Chilkat.Crypt2', @crypt OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @success int

    EXEC sp_OAMethod @crypt, 'UnlockComponent', @success OUT, 'Anything for 30-day trial'
    IF @success <> 1
      BEGIN
        PRINT 'Crypt component unlock failed'
        RETURN
      END

    --  Set the encryption algorithm to ARC4:
    EXEC sp_OASetProperty @crypt, 'CryptAlgorithm', 'arc4'

    --  We want the encrypted output to be a hex-encoded string.
    EXEC sp_OASetProperty @crypt, 'EncodingMode', 'hex'

    --  Encrypt some test vectors from Wikipedia:

    DECLARE @cipherText nvarchar(4000)

    DECLARE @plainText nvarchar(4000)

    --  The key length (in bits) is equal to the number of us-ascii
    --  bytes in our key string * 8.

    -- ARC4( "Key", "Plaintext" ) == BBF316E8D940AF0AD3
    EXEC sp_OASetProperty @crypt, 'KeyLength', 24
    EXEC sp_OAMethod @crypt, 'SetEncodedKey', NULL, 'Key', 'ascii'
    EXEC sp_OAMethod @crypt, 'EncryptStringENC', @cipherText OUT, 'Plaintext'

    PRINT @cipherText
    EXEC sp_OAMethod @crypt, 'DecryptStringENC', @plainText OUT, @cipherText

    PRINT @plainText

    -- ARC4( "Wiki", "pedia" ) == 1021BF0420
    EXEC sp_OASetProperty @crypt, 'KeyLength', 32
    EXEC sp_OAMethod @crypt, 'SetEncodedKey', NULL, 'Wiki', 'ascii'
    EXEC sp_OAMethod @crypt, 'EncryptStringENC', @cipherText OUT, 'pedia'

    PRINT @cipherText
    EXEC sp_OAMethod @crypt, 'DecryptStringENC', @plainText OUT, @cipherText

    PRINT @plainText

    -- ARC4( "Secret", "Attack at dawn" ) == 45A01F645FC35B383552544B9BF5
    EXEC sp_OASetProperty @crypt, 'KeyLength', 48
    EXEC sp_OAMethod @crypt, 'SetEncodedKey', NULL, 'Secret', 'ascii'
    EXEC sp_OAMethod @crypt, 'EncryptStringENC', @cipherText OUT, 'Attack at dawn'

    PRINT @cipherText
    EXEC sp_OAMethod @crypt, 'DecryptStringENC', @plainText OUT, @cipherText

    PRINT @plainText

    --  Note: The call to SetEncodedKey serves to set the key
    --  to the us-ascii bytes of the string.

END
GO