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Encrypting Passwords in ASP

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19 Jan 20021 min read 231.2K   55   41
A simple function to encrypt your users passwords

Introduction

Do you have a website where users need to login, and when they do you compare the password they enter with a column in a usertable? Some people do logins like this. It's easy to program and it works just fine. But what if someone got hold of the usertable and all the passwords of everyone? You may want to hide or encrypt the passwords in the usertable. Many programming languages have functions to do this. I make ASP-webpages, and I haven't found any quick functions to do this. There are plenty of components to do this, some free of charge even. But what if you cant install components on the webserver

Here is a short and neat way to encrypt your users passwords. You need two strings for it to work. Typically the username and the password.

Code

VBScript
Function encrypt(x1, x2)
    s = ""
    t = 0
    For i = 1 to len(x1)
        t = t + asc(mid(x1,i,1))
    Next
    For i = 1 to len(x2)
        y = (t + asc(mid(x2,i,1)) * asc(mid(x2,((i+1) mod len(x2)+1),1))) mod 255
        s = s & chr(y)
    Next
    For i = (len(x2) + 1) to 10
        If t>598.8 Then t = 598.8
        y = t^3*i mod 255
        s = s & chr(y)
    Next
    encrypt = s
End Function

If you want to test this function you can create an asp-page and upload it to your website. Here's my codelisting to encrypt.asp

ASP
<%
Function encrypt(x1, x2)
    s = ""
    t = 0
    For i = 1 to len(x1)
        t = t + asc(mid(x1,i,1))
    Next
    For i = 1 to len(x2)
        y = (t + asc(mid(x2,i,1)) * asc(mid(x2,((i+1) mod len(x2)+1),1))) mod 255
        s = s & chr(y)
    Next
    For i = (len(x2) + 1) to 10
        If t>598.8 Then t = 598.8
        y = t^3*i mod 255
        s = s & chr(y)
    Next
    encrypt = s
End Function
%>

<html>
<head>
 <title>Encrypt</title>
</head>

<body>
<% If request.form("name") = "" Then %>
<form action="encrypt.asp" method="post">
<input type="text" name="name"><input type="text" name="pass">
<input type="submit">
</form>
<% Else  %>
<% response.write encrypt(request.form("name"),request.form("pass")) %>
<% End If %>
</body>
</html>

Remarks

  • The function is not reversible, so there is no way to take the result and reverse it into the password. You will need to recreate the password with a new one (some users seem to forget their passwords and always wants it retreieved)
  • This is not a high-level encryption, but its good enough to hide it from lame hackers (hehe).
  • The password is always sent from the user inputpage to the page encrypting it. Somewhere in between a hacker can fetch it. Secure zones (SSL) can remedy this.
  • Feel free to use the code to whatever you like. But if you alter it make a post in the thread related to this article so we all can share the fun.

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here


Written By
Web Developer
Norway Norway
Tommy live in Tromsø, a city far up north in Norway. He does programming and webdevelopment for a living.

Comments and Discussions

 
BugOverflow exception Pin
Member 304391912-Jul-16 7:00
Member 304391912-Jul-16 7:00 
QuestionEncrypt &amp; Decrypt string [modified] Pin
c2love14-Nov-07 16:14
c2love14-Nov-07 16:14 
AnswerRe: Encrypt & Decrypt string Pin
tommy skaue14-Nov-07 21:43
tommy skaue14-Nov-07 21:43 
Questionencrypt & decrypt password Pin
red-apple11-Aug-07 0:04
red-apple11-Aug-07 0:04 
AnswerRe: encrypt & decrypt password Pin
tommy skaue11-Aug-07 2:56
tommy skaue11-Aug-07 2:56 
GeneralRe: encrypt & decrypt password Pin
kenbhavin13-May-08 21:18
kenbhavin13-May-08 21:18 
AnswerRe: encrypt & decrypt password Pin
kenbhavin13-May-08 21:16
kenbhavin13-May-08 21:16 
Generalone small change Pin
guildwyn24-Dec-06 11:17
guildwyn24-Dec-06 11:17 
QuestionHow to decrypt?? Pin
ShunHung14-Jul-05 17:11
sussShunHung14-Jul-05 17:11 
AnswerRe: How to decrypt?? Pin
Christian Graus14-Jul-05 17:47
protectorChristian Graus14-Jul-05 17:47 
Generalmodification of this code Pin
Anonymous2-Sep-04 14:24
Anonymous2-Sep-04 14:24 
GeneralRe: modification of this code Pin
tommy skaue2-Sep-04 21:13
tommy skaue2-Sep-04 21:13 
GeneralRe: modification of this code Pin
kryzchek18-May-05 7:40
kryzchek18-May-05 7:40 
GeneralRe: modification of this code Pin
tommy skaue18-May-05 10:30
tommy skaue18-May-05 10:30 
GeneralSame function ported to Perl Pin
Scott Offen21-Nov-03 7:55
Scott Offen21-Nov-03 7:55 
GeneralReturn value of Encrypt Function Pin
3-Mar-03 8:54
suss3-Mar-03 8:54 
GeneralIt wont work this way Pin
StarLite28-Jan-03 9:19
StarLite28-Jan-03 9:19 
GeneralRe: It wont work this way Pin
tommy skaue28-Jan-03 21:14
tommy skaue28-Jan-03 21:14 
GeneralRe: It wont work this way Pin
Anonymous29-Jan-03 3:34
Anonymous29-Jan-03 3:34 
GeneralRe: It wont work this way Pin
tommy skaue29-Jan-03 20:59
tommy skaue29-Jan-03 20:59 
Generalits a pretty good article Pin
Horatiu CRISTEA31-Jan-02 23:30
Horatiu CRISTEA31-Jan-02 23:30 
GeneralRe: its a pretty good article Pin
tommy skaue1-Feb-02 0:18
tommy skaue1-Feb-02 0:18 
GeneralRe: its a pretty good article Pin
Horatiu CRISTEA1-Feb-02 2:18
Horatiu CRISTEA1-Feb-02 2:18 
GeneralRe: its a pretty good article Pin
tommy skaue1-Feb-02 2:18
tommy skaue1-Feb-02 2:18 
GeneralTommy's son (off-topic) Pin
22-Jan-02 3:29
suss22-Jan-02 3:29 

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