Using Encryption and Decryption in an ASP page

Hi I was looking for implementing cryptography in an ASP page.

I found this following article of great use

The inc file

Dim sbox(255)
Dim key(255)

Sub RC4Initialize(strPwd)
dim tempSwap
dim a
dim b
intLength = len(strPwd)
For a = 0 To 255
key(a) = asc(mid(strpwd, (a mod intLength)+1, 1))
sbox(a) = a

b = 0
For a = 0 To 255

b = (b + sbox(a) + key(a)) Mod 256
tempSwap = sbox(a)
sbox(a) = sbox(b)
sbox(b) = tempSwap
End Sub

Function EnDeCrypt(plaintxt, psw)

dim temp
dim a
dim i
dim j
dim k
dim cipherby
dim cipher

i = 0
j = 0

RC4Initialize psw
For a = 1 To Len(plaintxt)
i = (i + 1) Mod 256
j = (j + sbox(i)) Mod 256
temp = sbox(i)
sbox(i) = sbox(j)
sbox(j) = temp
k = sbox((sbox(i) + sbox(j)) Mod 256)

cipherby = Asc(Mid(plaintxt, a, 1)) Xor k
cipher = cipher & Chr(cipherby)
EnDeCrypt = cipher
End Function


And following is the code for my asp page

<!–#include file=””–>

<form action=”G.asp” method=”post”>
dim psw, txt
dim strTemp
response.write “Encrypted Text =” & strTemp & “</Br>”
response.write “Decrypted Text =” & txt



Just copy and paste the code

That’s it …

Author: Nishant Rana

I love working in and sharing everything about Microsoft.NET technology !

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