by Andrew (5 Submissions)
Category: Encryption
Compatability: Visual Basic 3.0
Difficulty: Intermediate
Date Added: Wed 3rd February 2021
Rating: 
(3 Votes)
Converts a string of data to Base64. Base64 is an encryption algorithm used to encode binary data that is being sent through the internet.
Inputs
"sData" is the string that you want to encode.
Code Returns
It returns the encoded Base64 string.
VBcodersPublic Function sBase64Enc(sData As String) As String
'Base64 Conversion
'Example:
' Dim sMyConv As String
' sMyConv = sBase64Enc("Hello =)")
On Error Resume Next
Dim x As Long
Dim nByte As Long
Dim nAsc As Long
Dim sBin As String
Dim sRet As String
Dim sByte As String
Dim nIncr As Integer
'Convert the data to standard
'base-2 binary.
For x = 1 To Len(sData)
DoEvents
nByte = CLng(Asc(Mid(sData, x, 1)))
For y = 1 To 8
nIncr = CInt(2 ^ (8 - y))
If CLng(nByte) - CLng(nIncr) >= 0 Then
nByte = nByte - CLng(nIncr)
sBin = sBin & "1"
Else: sBin = sBin & "0"
End If
Next y
Next x
'Check to see if the conversion was completed
'and if so, encode the data using the Base64
'algorithm.
If CLng(Len(sBin) Mod 8) = 0 Then
'Binary conversion ok!, parse
'every 6 bits of data.
For x = 1 To Len(sBin) Step 6
DoEvents
sByte = Mid(sBin, x, 6)
For y = 1 To Len(sByte)
DoEvents
nByte = Val(Mid(sByte, y, 1))
If Not nByte = 0 Then
nAsc = nAsc + CInt(2 ^ (6 - (y)))
End If
Next y
'Base64 Conversion:
Select Case (nAsc + 65)
Case Is > 90 'Either lowercase or numeric
If (nAsc + 71) > 122 Then
sByte = Chr(nAsc - 4)
Else
sByte = Chr(nAsc + 71)
End If
Case Is < 90 'Uppercase
sByte = Chr(nAsc + 65)
End Select
'Append new characters to the final
'string and reset temporary variables.
sRet = sRet & sByte
nAsc = 0
Next x
End If
'Finished, output the data to the
'function variable.
sBase64Enc = sRet
End Function
