(Excel) RC2 Encryption and Decryption

RC2 encryption. The Chilkat encryption component supports RC2 encryption in both ECB (Electronic Cookbook) and CBC (Cipher-Block Chaining) modes. The key size may range from 8 bits to 1024 bits.

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' This example assumes the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim crypt As Chilkat.Crypt2
Set crypt = Chilkat.NewCrypt2

' Set the encryption algorithm = "rc2"	
crypt.CryptAlgorithm = "rc2"

' CipherMode may be "ecb" or "cbc"
crypt.CipherMode = "cbc"

' KeyLength may range from 8 bits to 1024 bits
crypt.KeyLength = 128

' RC2 also has an effective key length property
' which can also range from 8 bits to 1024 bits:
crypt.Rc2EffectiveKeyLength = 128

' The padding scheme determines the contents of the bytes
' that are added to pad the result to a multiple of the
' encryption algorithm's block size.  RC2 has a block
' size of 8 bytes, so encrypted output is always
' a multiple of 8.
crypt.PaddingScheme = 0

' EncodingMode specifies the encoding of the output for
' encryption, and the input for decryption.
' It may be "hex", "url", "base64", or "quoted-printable".
crypt.EncodingMode = "hex"

' An initialization vector is required if using CBC mode.
' ECB mode does not use an IV.
' The length of the IV is equal to the algorithm's block size.
' It is NOT equal to the length of the key.

ivHex = "0001020304050607"
crypt.SetEncodedIV ivHex,"hex"

' The secret key must equal the size of the key.
' For 128-bit encryption, the binary secret key is 16 bytes.

keyHex = "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F"
crypt.SetEncodedKey keyHex,"hex"

' Encrypt a string...
' The input string is 44 ANSI characters (i.e. 44 bytes), so
' the output should be 48 bytes (a multiple of 8).
' Because the output is a hex string, it should
' be 96 characters long (2 chars per byte).

encStr = crypt.EncryptStringENC("The quick brown fox jumps over the lazy dog.")
Debug.Print encStr

' Now decrypt:

decStr = crypt.DecryptStringENC(encStr)
Debug.Print decStr