(Visual FoxPro) ARC4 Encryption (ARCFOUR)

ARC4 (ARCFOUR) encryption. The Chilkat encryption component supports the ARC4 streaming encryption algorithm.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loCrypt
LOCAL lcKeyHex
LOCAL lcEncStr
LOCAL lcDecStr

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

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Crypt2')
loCrypt = CreateObject('Chilkat.Crypt2')

* Set the encryption algorithm = "arc4"	
loCrypt.CryptAlgorithm = "arc4"

* KeyLength may range from 1 byte to 256 bytes.
* (i.e. 8 bits to 2048 bits)
* ARC4 key sizes are typically in the range of 
* 40 to 128 bits.
* The KeyLength property is specified in bits:
loCrypt.KeyLength = 128

* Note: The PaddingScheme and CipherMode properties
* do not apply w/ ARC4.  ARC4 does not encrypt in blocks --
* it is a streaming encryption algorithm. The number of output bytes
* is exactly equal to the number of input bytes.

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

* Note: ARC4 does not utilize initialization vectors.  IV's only
* apply to block encryption algorithms.  

* The secret key must equal the size of the key.
* For 128-bit encryption, the binary secret key is 16 bytes.
lcKeyHex = "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F"
loCrypt.SetEncodedKey(lcKeyHex,"hex")

* Encrypt a string...
* The output length is exactly equal to the input.  In this
* example, the input string is 44 chars (ANSI bytes) so the
* output is 44 bytes -- and when hex encoded results in an
* 88-char string (2 chars per byte for the hex encoding).
lcEncStr = loCrypt.EncryptStringENC("The quick brown fox jumps over the lazy dog.")
? lcEncStr

* Now decrypt:
lcDecStr = loCrypt.DecryptStringENC(lcEncStr)
? lcDecStr

RELEASE loCrypt