66 lines
2.1 KiB
QBasic
66 lines
2.1 KiB
QBasic
Option Explicit
|
|
Private Const cstBase64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
|
|
Private arrBase64() As String
|
|
|
|
Public Function Base64Encode(strSource As String) As String'±àÂë
|
|
On Error Resume Next
|
|
If UBound(arrBase64) = -1 Then
|
|
arrBase64 = Split(StrConv(cstBase64, vbUnicode), vbNullChar)
|
|
End If
|
|
Dim arrB() As Byte, bTmp(2) As Byte, bT As Byte
|
|
Dim I As Long, J As Long
|
|
arrB = StrConv(strSource, vbFromUnicode)
|
|
|
|
J = UBound(arrB)
|
|
For I = 0 To J Step 3
|
|
Erase bTmp
|
|
bTmp(0) = arrB(I + 0)
|
|
bTmp(1) = arrB(I + 1)
|
|
bTmp(2) = arrB(I + 2)
|
|
|
|
bT = (bTmp(0) And 252) / 4
|
|
Base64Encode = Base64Encode & arrBase64(bT)
|
|
|
|
bT = (bTmp(0) And 3) * 16
|
|
bT = bT + bTmp(1) \ 16
|
|
Base64Encode = Base64Encode & arrBase64(bT)
|
|
|
|
bT = (bTmp(1) And 15) * 4
|
|
bT = bT + bTmp(2) \ 64
|
|
If I + 1 <= J Then
|
|
Base64Encode = Base64Encode & arrBase64(bT)
|
|
Else
|
|
Base64Encode = Base64Encode & "="
|
|
End If
|
|
|
|
bT = bTmp(2) And 63
|
|
If I + 2 <= J Then
|
|
Base64Encode = Base64Encode & arrBase64(bT)
|
|
Else
|
|
Base64Encode = Base64Encode & "="
|
|
End If
|
|
Next
|
|
End Function
|
|
|
|
Public Function Base64Decode(strEncoded As String) As String'½âÂë
|
|
On Error Resume Next
|
|
Dim arrB() As Byte, bTmp(3) As Byte, bT As Long, bRet() As Byte
|
|
Dim I As Long, J As Long
|
|
arrB = StrConv(strEncoded, vbFromUnicode)
|
|
J = InStr(strEncoded & "=", "=") - 2
|
|
ReDim bRet(J - J \ 4 - 1)
|
|
For I = 0 To J Step 4
|
|
Erase bTmp
|
|
bTmp(0) = (InStr(cstBase64, Chr(arrB(I))) - 1) And 63
|
|
bTmp(1) = (InStr(cstBase64, Chr(arrB(I + 1))) - 1) And 63
|
|
bTmp(2) = (InStr(cstBase64, Chr(arrB(I + 2))) - 1) And 63
|
|
bTmp(3) = (InStr(cstBase64, Chr(arrB(I + 3))) - 1) And 63
|
|
|
|
bT = bTmp(0) * 2 ^ 18 + bTmp(1) * 2 ^ 12 + bTmp(2) * 2 ^ 6 + bTmp(3)
|
|
|
|
bRet((I \ 4) * 3) = bT \ 65536
|
|
bRet((I \ 4) * 3 + 1) = (bT And 65280) \ 256
|
|
bRet((I \ 4) * 3 + 2) = bT And 255
|
|
Next
|
|
Base64Decode = StrConv(bRet, vbUnicode)
|
|
End Function |