<%
const TBL_LOGIN = "users_table_name"
const FLD_PASS = "password_field_name"
const DB_NAME = "db_name"

Dim dbconnection
Set dbConnection = server.CreateObject("ADODB.Connection")

Dim strConnection
strConnection = "PROVIDER=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=" & Server.MapPath(DB_NAME)

dbConnection.ConnectionString = strConnection
dbConnection.Open

Dim RecordSet
Set RecordSet = server.CreateObject("ADODB.Recordset")

Dim SQL
SQL = "SELECT * FROM " & TBL_LOGIN

RecordSet.open SQL , dbConnection,1,2

total=0
enc=0
doencrypt=false

if Request("do")="encrypt" then doencrypt=true

do until RecordSet.eof
if doencrypt then
total=total+1

if not encrypted(RecordSet(FLD_PASS)) then
RecordSet(FLD_PASS)=md5(RecordSet(FLD_PASS))
RecordSet.Update
end if

enc=enc+1

else
total=total+1
if encrypted(RecordSet(FLD_PASS)) then
enc=enc+1
end if

RecordSet.MoveNext
loop

Recordset.Close
Set Recordset=Nothing
dbconnection.Close
Set dbconnection=Nothing

function encrypted(str)
if len(str)<>32 then
encrypted=false
exit function
end if

dim i
for i=1 to 32
c = asc(mid(str,i,1))
if (c<asc("0") and c>asc("9")) and (c<asc("a") or c>asc("f")) then
encrypted=false
exit function
end if
next

encrypted=true

end function
%>

<html>
<head><title>Encrypt passwords</title></head>
<body>
Total passwords in the table - <%=total %> 
<% if enc=total and total>0 then %>
All passwords are encrypted.
<% elseif total>0 then %>
Unencrypted - <%=(total-enc)%> 
Click "GO" to encrypt <%=(total-enc) %> passwords. 
WARNING! There will be no way to decipher the passwords. 
<input type=button value="GO" onclick="window.location='encrypt.asp?do=encrypt';">
<% end if %>
</body>
</html>