ASCII / ANSI Secret Key in Symmetric Encryption

Chilkat ActiveX Downloads

ActiveX for 32-bit and 64-bit Windows

Using an ASCII (or ANSI) secret key w/ symmetric encryption: AES, Blowfish, Twofish, RC2, 3DES, etc.

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
set crypt = Server.CreateObject("Chilkat_9_5_0.Crypt2")

success = crypt.UnlockComponent("Anything for 30-day trial")
If (success <> 1) Then
    Response.Write "Crypt component unlock failed" & "<br>"

End If

'  A frequent support question goes something like this:
'  ------------------
'  I am not able to decrypt strings encrypted using
'  cryptix.jce.provider.key.RawSecretKey (Java) like I would normally do.

' The key generation is being done with the Rijndael algorithm (256-bit)
'  The AES encryption algorithm is "Rijndael/ECB/PKCS#5"

'  The 32 character source key I'm using is this:
'  1234567890123456789012345678912
' 
'  ------------------
'  The customer tries to call GenerateSecretKey to
'  convert the 32-character source key to a binary secret key,
'  but this is incorrect (in this case).  GenerateSecretKey
'  hashes a string of any length and produces binary hash output
'  that is of the appropriate size to be used as a secret key.

'  The telltale sign is that in this case, the string is the exact
'  length of the secret key.  32 ANSI characters = 256 bits.
'  Therefore, it is obvious that the bytes of the binary
'  secret key should be the exact ascii character values
'  of the string.

encKey = "1234567890123456789012345678912"

crypt.CryptAlgorithm = "aes"
'  Mode is "ecb" or "cbc"
crypt.CipherMode = "ecb"
crypt.KeyLength = 256

'  Call SetEncodedKey with "ascii" to tell the component
'  to use the ascii-bytes as the binary secret key.
'  Make sure you call this after setting the KeyLength.
crypt.SetEncodedKey encKey,"ascii"

crypt.EncodingMode = "base64"
text = "The quick brown fox jumped over the lazy dog."

'  Encrypt a string and return the binary encrypted data
'  in a base-64 encoded string.
encText = crypt.EncryptStringENC(text)

Response.Write encText & "<br>"

'  Decrypt and show the original string:
decryptedText = crypt.DecryptStringENC(encText)

Response.Write decryptedText & "<br>"
%>
</body>
</html>