Dim Base64Chars
Base64Chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
Function
B64Decode( 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
B64Decode = 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 |
