| Function Base64Encode(inData) 'rfc1521 '2001 Antonin Foller, PSTRUH Software, http://pstruh.cz Const Base64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" Dim cOut, sOut, I 'For each group of 3 bytes For I = 1 To Len(inData) Step 3 Dim nGroup, pOut, sGroup 'Create one long from this 3 bytes. nGroup = &H10000 * Asc(Mid(inData, I, 1)) + _ &H100 * MyASC(Mid(inData, I + 1, 1)) + MyASC(Mid(inData, I + 2, 1)) 'Oct splits the long To 8 groups with 3 bits nGroup = Oct(nGroup) 'Add leading zeros nGroup = String(8 - Len(nGroup), "0") & nGroup 'Convert To base64 pOut = Mid(Base64, CLng("&o" & Mid(nGroup, 1, 2)) + 1, 1) + _ Mid(Base64, CLng("&o" & Mid(nGroup, 3, 2)) + 1, 1) + _ Mid(Base64, CLng("&o" & Mid(nGroup, 5, 2)) + 1, 1) + _ Mid(Base64, CLng("&o" & Mid(nGroup, 7, 2)) + 1, 1) 'Add the part To OutPut string sOut = sOut + pOut 'Add a new line For Each 76 chars In dest (76*3/4 = 57) 'If (I + 2) Mod 57 = 0 Then sOut = sOut + vbCrLf Next Select Case Len(inData) Mod 3 Case 1: '8 bit final sOut = Left(sOut, Len(sOut) - 2) + "==" Case 2: '16 bit final sOut = Left(sOut, Len(sOut) - 1) + "=" End Select Base64Encode = sOut End Function Function MyASC(OneChar) If OneChar = "" Then MyASC = 0 Else MyASC = Asc(OneChar) End Function ' Decodes a base-64 encoded string (BSTR type). Function Base64Decode(ByVal base64String) 'rfc1521 '1999 Antonin Foller, PSTRUH Software, http://pstruh.cz Const Base64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" Dim dataLength, sOut, groupBegin 'remove white spaces, If any base64String = Replace(base64String, vbCrLf, "") base64String = Replace(base64String, vbTab, "") base64String = Replace(base64String, " ", "") 'The source must consists from groups with Len of 4 chars dataLength = Len(base64String) If dataLength Mod 4 <> 0 Then Err.Raise 1, "Base64Decode", "Bad Base64 string." Exit Function End If ' Now decode each group: For groupBegin = 1 To dataLength Step 4 Dim numDataBytes, CharCounter, thisChar, thisData, nGroup, pOut ' Each data group encodes up To 3 actual bytes. numDataBytes = 3 nGroup = 0 For CharCounter = 0 To 3 ' Convert each character into 6 bits of data, And add it To ' an integer For temporary storage. If a character is a '=', there ' is one fewer data byte. (There can only be a maximum of 2 '=' In ' the whole string.) thisChar = Mid(base64String, groupBegin + CharCounter, 1) If thisChar = "=" Then numDataBytes = numDataBytes - 1 thisData = 0 Else thisData = InStr(Base64, thisChar) - 1 End If If thisData = -1 Then Err.Raise 2, "Base64Decode", "Bad character In Base64 string." Exit Function End If nGroup = 64 * nGroup + thisData Next 'Hex splits the long To 6 groups with 4 bits nGroup = Hex(nGroup) 'Add leading zeros nGroup = String(6 - Len(nGroup), "0") & nGroup 'Convert the 3 byte hex integer (6 chars) To 3 characters pOut = Chr(CByte("&H" & Mid(nGroup, 1, 2))) + _ Chr(CByte("&H" & Mid(nGroup, 3, 2))) + _ Chr(CByte("&H" & Mid(nGroup, 5, 2))) 'add numDataBytes characters To out string sOut = sOut & Left(pOut, numDataBytes) Next Base64Decode = sOut End Function |
'Language/VB'에 해당되는 글 1건
- 2006.10.17 VB Base64 Encoder, Decoder
