Cryptographic decryption-ASP instance

Encryption | decryption | encryption | encryption | Before decrypting: 1234567890

After encryption: Mtizndu2nzg5ma

After decryption: 1234567890

Source:

<%
OPTION EXPLICIT
Const BASE_64_MAP_INIT = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789+/"
Dim newline
Dim Base64encmap (63)
Dim Base64decmap (127)
' Initialization function
Public SUB Initcodecs ()
' Initialize variable
NewLine = "<P>" & Chr (km) & Chr (10)
Dim max, IDX
max = Len (base_64_map_init)
For idx = 0 to Max-1
Base64encmap (IDX) = Mid (Base_64_map_init, IDX + 1, 1)
Next
For idx = 0 to Max-1
Base64decmap (ASC (Base64encmap (idx)) = IDX
Next
End SUB
' Base64 encryption function
Public FUNCTION Base64Encode (plain)
If Len (plain) = 0 Then
Base64Encode = ""
Exit function
End If
Dim ret, Ndx, By3, second, third
By3 = (len (plain) \ 3) * 3
NDX = 1
Do While Ndx <= by3
A = ASC (Mid (Plain, ndx+0, 1))
Second = ASC (Mid (Plain, ndx+1, 1))
Third = ASC (Mid (Plain, ndx+2, 1))
RET = ret & Base64encmap ((4) and 63)
RET = ret & Base64encmap ((a) + ((second) and 15))
RET = ret & Base64encmap ((Second * 4) and + ((third) and 3))
RET = ret & Base64encmap (third and 63)
NDX = ndx + 3
Loop
If By3 < Len (plain) Then
A = ASC (Mid (Plain, ndx+0, 1))
RET = ret & Base64encmap ((4) and 63)
if (Len (plain) MOD 3) = 2 Then
Second = ASC (Mid (Plain, ndx+1, 1))
RET = ret & Base64encmap ((a) + ((second) and 15))
RET = ret & Base64encmap ((Second * 4) and 60))
Else
RET = ret & Base64encmap ((a) and 48)
ret = Ret ' & ' = '
End If
ret = Ret ' & ' = '
End If
Base64Encode = RET
End FUNCTION
' Base64 decryption function
Public FUNCTION Base64decode (scrambled)
If Len (scrambled) = 0 Then
Base64decode = ""
Exit function
End If
Dim Reallen
Reallen = Len (scrambled)
Do while mid (scrambled, Reallen, 1) = "="
Reallen = realLen-1
Loop
Dim ret, Ndx, By4, A, second, third, fourth
ret = ""
By4 = (reallen \ 4) * 4
NDX = 1
Do While Ndx <= by4
i = BASE64DECMAP (ASC (Scrambled, ndx+0, 1))
Second = BASE64DECMAP (ASC (Scrambled, ndx+1, 1))
Third = Base64decmap (ASC (Scrambled, ndx+2, 1))
Fourth = BASE64DECMAP (ASC (Scrambled, ndx+3, 1))
RET = ret & Chr (((4) and 255) + ((second) and 3))
RET = ret & Chr ((second *) and 255) + ((third \ 4) and 15))
RET = ret & Chr ((third *) and 255) + (fourth and 63))
NDX = ndx + 4
Loop
If Ndx < Reallen Then
i = BASE64DECMAP (ASC (Scrambled, ndx+0, 1))
Second = BASE64DECMAP (ASC (Scrambled, ndx+1, 1))
RET = ret & Chr (((4) and 255) + ((second) and 3))
If Reallen MOD 4 = 3 Then
Third = Base64decmap (ASC (mid scrambled,ndx+2,1))
RET = ret & Chr ((second *) and 255) + ((third \ 4) and 15))
End If
End If
Base64decode = RET
End FUNCTION
' Initialization
Call Initcodecs
' Test code
Dim InP, Encode
INP = "1234567890"
encode = Base64Encode (INP)
Response.Write "Before encryption:" & INP & NewLine
Response.Write "After encryption:" & Encode & NewLine
Response.Write "After decryption:" & Base64decode (encode) & newline
%>