Code:
' Functions to provide encoding/decoding of strings with Base64. ' ' Encoding: myEncodedString = base64_encode( inputString ) ' Decoding: myDecodedString = base64_decode( encodedInputString ) ' ' Programmed by Markus Hartsmar for ShameDesigns in 2002. ' Email me at: mark@shamedesigns.com ' Visit our website at: http://www.shamedesigns.com/ ' Dim Base64Chars Base64Chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" & _ "abcdefghijklmnopqrstuvwxyz" & _ "0123456789" & _ "+/" ' Functions for encoding string to Base64 Public Function base64_encode( byVal strIn ) Dim c1, c2, c3, w1, w2, w3, w4, n, strOut For n = 1 To Len( strIn ) Step 3 c1 = Asc( Mid( strIn, n, 1 ) ) c2 = Asc( Mid( strIn, n + 1, 1 ) + Chr(0) ) c3 = Asc( Mid( strIn, n + 2, 1 ) + Chr(0) ) w1 = Int( c1 / 4 ) : w2 = ( c1 And 3 ) * 16 + Int( c2 / 16 ) If Len( strIn ) >= n + 1 Then w3 = ( c2 And 15 ) * 4 + Int( c3 / 64 ) Else w3 = -1 End If If Len( strIn ) >= n + 2 Then w4 = c3 And 63 Else w4 = -1 End If strOut = strOut + mimeencode( w1 ) + mimeencode( w2 ) + _ mimeencode( w3 ) + mimeencode( w4 ) Next base64_encode = strOut End Function Private Function mimeencode( byVal intIn ) If intIn >= 0 Then mimeencode = Mid( Base64Chars, intIn + 1, 1 ) Else mimeencode = "" End If End Function ' Function to decode string from Base64 Public Function base64_decode( byVal strIn ) Dim w1, w2, w3, w4, n, strOut For n = 1 To Len( strIn ) Step 4 w1 = mimedecode( Mid( strIn, n, 1 ) ) w2 = mimedecode( Mid( strIn, n + 1, 1 ) ) w3 = mimedecode( Mid( strIn, n + 2, 1 ) ) w4 = mimedecode( Mid( strIn, n + 3, 1 ) ) If w2 >= 0 Then _ strOut = strOut + _ Chr( ( ( w1 * 4 + Int( w2 / 16 ) ) And 255 ) ) If w3 >= 0 Then _ strOut = strOut + _ Chr( ( ( w2 * 16 + Int( w3 / 4 ) ) And 255 ) ) If w4 >= 0 Then _ strOut = strOut + _ Chr( ( ( w3 * 64 + w4 ) And 255 ) ) Next base64_decode = strOut End Function Private Function mimedecode( byVal strIn ) If Len( strIn ) = 0 Then mimedecode = -1 : Exit Function Else mimedecode = InStr( Base64Chars, strIn ) - 1 End If End Function