VB中实现BASE64加密
以下是网上关于在VBscript中的一种BASE64的加密代码，过程是将将Unicode编码的字符串，转换成Ansi编码的字符串
再以BASE64加密，解密时再以BASE64解密再以Ansi编码转换回Unicode还原成原来的文本，如何将以下此代码
修改成适合在VB中调用的加密方式，试来试去都不成功，请大家指点.
sBASE_64_CHARACTERS = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
sBASE_64_CHARACTERS = strUnicode2Ansi(sBASE_64_CHARACTERS)
Function strUnicodeLen(asContents)
'计算unicode字符串的Ansi编码的长度
asContents1="a"&asContents
len1=len(asContents1)
k=0
for i=1 to len1
asc1=asc(mid(asContents1,i,1))
if asc1<0 then asc1=65536+asc1
if asc1>255 then
k=k+2
else
k=k+1
end if
next
strUnicodeLen=k-1
End Function
Function strUnicode2Ansi(asContents)
'将Unicode编码的字符串，转换成Ansi编码的字符串
strUnicode2Ansi=""
len1=len(asContents)
for i=1 to len1
varchar=mid(asContents,i,1)
varasc=asc(varchar)
if varasc<0 then varasc=varasc+65536
if varasc>255 then
varHex=Hex(varasc)
varlow=left(varHex,2)
varhigh=right(varHex,2)
strUnicode2Ansi=strUnicode2Ansi & chrb("&H" & varlow ) & chrb("&H" & varhigh )
else
strUnicode2Ansi=strUnicode2Ansi & chrb(varasc)
end if
next
End function
Function strAnsi2Unicode(asContents)
'将Ansi编码的字符串，转换成Unicode编码的字符串
strAnsi2Unicode = ""
len1=lenb(asContents)
if len1=0 then exit function
for i=1 to len1
varchar=midb(asContents,i,1)
varasc=ascb(varchar)
if varasc > 127 then
strAnsi2Unicode = strAnsi2Unicode & chr(ascw(midb(asContents,i+1,1) & varchar))
i=i+1
else
strAnsi2Unicode = strAnsi2Unicode & chr(varasc)
end if
next
End function
Function Base64encode(asContents)
'将Ansi编码的字符串进行Base64编码
'asContents应当是ANSI编码的字符串（二进制的字符串也可以）
Dim lnPosition
Dim lsResult
Dim Char1
Dim Char2
Dim Char3
Dim Char4
Dim Byte1
Dim Byte2
Dim Byte3
Dim SaveBits1
Dim SaveBits2
Dim lsGroupBinary
Dim lsGroup64
Dim m4,len1,len2
len1=Lenb(asContents)
if len1<1 then
Base64encode=""
exit Function
end if
m3=Len1 Mod 3
If M3 > 0 Then asContents = asContents & String(3-M3, chrb(0))
'补足位数是为了便于计算
IF m3 > 0 THEN
len1=len1+(3-m3)
len2=len1-3
else
len2=len1
end if
lsResult = ""
For lnPosition = 1 To len2 Step 3
lsGroup64 = ""
lsGroupBinary = Midb(asContents, lnPosition, 3)
Byte1 = Ascb(Midb(lsGroupBinary, 1, 1)): SaveBits1 = Byte1 And 3
Byte2 = Ascb(Midb(lsGroupBinary, 2, 1)): SaveBits2 = Byte2 And 15
Byte3 = Ascb(Midb(lsGroupBinary, 3, 1))
Char1 = Midb(sBASE_64_CHARACTERS, ((Byte1 And 252) \ 4) + 1, 1)
Char2 = Midb(sBASE_64_CHARACTERS, (((Byte2 And 240) \ 16) Or (SaveBits1 * 16) And &HFF) + 1, 1)
Char3 = Midb(sBASE_64_CHARACTERS, (((Byte3 And 192) \ 64) Or (SaveBits2 * 4) And &HFF) + 1, 1)
Char4 = Midb(sBASE_64_CHARACTERS, (Byte3 And 63) + 1, 1)
lsGroup64 = Char1 & Char2 & Char3 & Char4
lsResult = lsResult & lsGroup64
Next
'处理最后剩余的几个字符
if M3 > 0 then
lsGroup64 = ""
lsGroupBinary = Midb(asContents, len2+1, 3)
Byte1 = Ascb(Midb(lsGroupBinary, 1, 1)): SaveBits1 = Byte1 And 3
Byte2 = Ascb(Midb(lsGroupBinary, 2, 1)): SaveBits2 = Byte2 And 15
Byte3 = Ascb(Midb(lsGroupBinary, 3, 1))
Char1 = Midb(sBASE_64_CHARACTERS, ((Byte1 And 252) \ 4) + 1, 1)
Char2 = Midb(sBASE_64_CHARACTERS, (((Byte2 And 240) \ 16) Or (SaveBits1 * 16) And &HFF) + 1, 1)
Char3 = Midb(sBASE_64_CHARACTERS, (((Byte3 And 192) \ 64) Or (SaveBits2 * 4) And &HFF) + 1, 1)
if M3=1 then
lsGroup64 = Char1 & Char2 & ChrB(61) & ChrB(61) '用=号补足位数
else
lsGroup64 = Char1 & Char2 & Char3 & ChrB(61) '用=号补足位数
end if
lsResult = lsResult & lsGroup64
end if
Base64encode = lsResult
End Function
Function Base64decode(asContents)
'将Base64编码字符串转换成Ansi编码的字符串
'asContents应当也是ANSI编码的字符串（二进制的字符串也可以）
Dim lsResult
Dim lnPosition
Dim lsGroup64, lsGroupBinary
Dim Char1, Char2, Char3, Char4
Dim Byte1, Byte2, Byte3
Dim M4,len1,len2
len1= Lenb(asContents)
M4 = len1 Mod 4
if len1 < 1 or M4 > 0 then
'字符串长度应当是4的倍数
Base64decode = ""
exit Function
end if
'判断最后一位是不是 = 号
'判断倒数第二位是不是 = 号
'这里m4表示最后剩余的需要单独处理的字符个数
if midb(asContents, len1, 1) = chrb(61) then m4=3
if midb(asContents, len1-1, 1) = chrb(61) then m4=2
if m4 = 0 then
len2=len1
else
len2=len1-4
end if
For lnPosition = 1 To Len2 Step 4
lsGroupBinary = ""
lsGroup64 = Midb(asContents, lnPosition, 4)
Char1 = InStrb(sBASE_64_CHARACTERS, Midb(lsGroup64, 1, 1)) - 1
Char2 = InStrb(sBASE_64_CHARACTERS, Midb(lsGroup64, 2, 1)) - 1
Char3 = InStrb(sBASE_64_CHARACTERS, Midb(lsGroup64, 3, 1)) - 1
Char4 = InStrb(sBASE_64_CHARACTERS, Midb(lsGroup64, 4, 1)) - 1
Byte1 = Chrb(((Char2 And 48) \ 16) Or (Char1 * 4) And &HFF)
Byte2 = lsGroupBinary & Chrb(((Char3 And 60) \ 4) Or (Char2 * 16) And &HFF)
Byte3 = Chrb((((Char3 And 3) * 64) And &HFF) Or (Char4 And 63))
lsGroupBinary = Byte1 & Byte2 & Byte3
lsResult = lsResult & lsGroupBinary
Next
'处理最后剩余的几个字符
if M4 > 0 then
lsGroupBinary = ""
lsGroup64 = Midb(asContents, len2+1, m4) & chrB(65) 'chr(65)=A，转换成值为0
if M4=2 then '补足4位，是为了便于计算
lsGroup64 = lsGroup64 & chrB(65)
end if
Char1 = InStrb(sBASE_64_CHARACTERS, Midb(lsGroup64, 1, 1)) - 1
Char2 = InStrb(sBASE_64_CHARACTERS, Midb(lsGroup64, 2, 1)) - 1
Char3 = InStrb(sBASE_64_CHARACTERS, Midb(lsGroup64, 3, 1)) - 1
Char4 = InStrb(sBASE_64_CHARACTERS, Midb(lsGroup64, 4, 1)) - 1
Byte1 = Chrb(((Char2 And 48) \ 16) Or (Char1 * 4) And &HFF)
Byte2 = lsGroupBinary & Chrb(((Char3 And 60) \ 4) Or (Char2 * 16) And &HFF)
Byte3 = Chrb((((Char3 And 3) * 64) And &HFF) Or (Char4 And 63))
if M4=2 then
lsGroupBinary = Byte1
elseif M4=3 then
lsGroupBinary = Byte1 & Byte2
end if
lsResult = lsResult & lsGroupBinary
end if
Base64decode = lsResult
End Function
问题点数：20、回复次数：4Top
1 楼thirdapple（.:RNPA:.陨落雕 - 芝兰宝树）回复于 2005-02-04 22:04:59 得分 10
Base64是编码，不是加密……是用64个字符表示文件的一种方法，防止在传送email的时候丢失数据……Top
2 楼sworddx（.:RNPA:. hillin）回复于 2005-02-04 22:17:48 得分 0
同意陨落雕观点。Top
3 楼leekkeek（期待者）回复于 2005-02-05 08:16:19 得分 0
up,学习Top
4 楼_l_（蠢瓜)(每天最多回答2个问题）回复于 2005-02-05 09:21:34 得分 10
TEXT TO JPG
Base64DecodeFile(App.Path & "\11.TXT", App.Path & "\11.jpg")
模块里的
'----------------------------------------
'- 发送邮件代码 jinesc 2004年5月26日整理
'----------------------------------------
Option Explicit
' ConnectToServer(strServer, wsk, strSrvPort)
' ConnectToServer "pop.microsoft.com", Winsock1, 25
' Normally leave out the last arguement and let the Winsock control use
' the default port.
' ExtractArgument(ArgNum, srchstr, Delim)
' ExtractArgument(3, "No 1, No 2, No 3", ",") Would return No 3
' I did not have time to sort out the variable names in this function,
' so if you can be bothered to, please send it to me at sam@vbsquare.com
Function ExtractArgument(ArgNum As Integer, srchstr As String, Delim As String) As String
On Error GoTo Err_ExtractArgument
Dim ArgCount As Integer
Dim LastPos As Integer
Dim Pos As Integer
Dim Arg As String
Arg = ""
LastPos = 1
If ArgNum = 1 Then Arg = srchstr
Do While InStr(srchstr, Delim) > 0
Pos = InStr(LastPos, srchstr, Delim)
If Pos = 0 Then
If ArgCount = ArgNum - 1 Then Arg = Mid(srchstr, LastPos)
Exit Do
Else
ArgCount = ArgCount + 1
If ArgCount = ArgNum Then
Arg = Mid(srchstr, LastPos, Pos - LastPos)
Exit Do
End If
End If
LastPos = Pos + 1
Loop
ExtractArgument = Arg
Exit Function
Err_ExtractArgument:
' MsgBox "Error " & Err & ": " & Error
Resume Next
End Function
' SendMail(strFrom, strTo, strSubject, strBody, wsk, strAttachName, txtEncodedFile)
' SendMail "me@mymail.com", "you@yourmail.com", "Test Message", "Body", Winsock1, "myfile.ext", txtEncodedFile
' If you omit the last two arguements then no file is attached
' Before attaching a file, you must first encode it using the Base64EncodeFile function
' Wait(WaitTime)
' Wait 0.5
Public Sub Wait(WaitTime)
Dim StartTime As Double
StartTime = Timer
Do While Timer < StartTime + WaitTime
If Timer > 86395 Or Timer = 0 Then Exit Do
DoEvents
Loop
End Sub
Public Function Base64EncodeFile(Infile As String, Outfile As String)
Dim FnumIn As Integer, FnumOut As Integer
Dim mInByte(3) As Byte, mOutByte(4) As Byte
Dim myByte As Byte
Dim i As Integer, LineLen As Integer, j As Integer
FnumIn = FreeFile()
Open Infile For Binary As #FnumIn
FnumOut = FreeFile()
Open Outfile For Binary As #FnumOut
While Not EOF(FnumIn)
i = 0
Do While i < 3
Get #FnumIn, , myByte
If Not EOF(FnumIn) Then
mInByte(i) = myByte
i = i + 1
Else
Exit Do
End If
Loop
Base64EncodeByte mInByte, mOutByte, i
For j = 0 To 3
Put #FnumOut, , mOutByte(j)
Next j
LineLen = LineLen + 1
If LineLen * 4 > 70 Then
Put #FnumOut, , vbCrLf
LineLen = 0
End If
Wend
Close FnumOut
Close FnumIn
End Function
Sub Base64EncodeByte(mInByte() As Byte, mOutByte() As Byte, Num As Integer)
Dim tByte As Byte
Dim i As Integer
If Num = 1 Then
mInByte(1) = 0
mOutByte(2) = 0
ElseIf Num = 2 Then
mInByte(2) = 0
End If
tByte = mInByte(0) And &HFC
mOutByte(0) = tByte / 4
tByte = ((mInByte(0) And &H3) * 16) + (mInByte(1) And &HF0) / 16
mOutByte(1) = tByte
tByte = ((mInByte(1) And &HF) * 4) + ((mInByte(2) And &HC0) / 64)
mOutByte(2) = tByte
tByte = (mInByte(2) And &H3F)
mOutByte(3) = tByte
For i = 0 To 3
If mOutByte(i) >= 0 And mOutByte(i) <= 25 Then
mOutByte(i) = mOutByte(i) + Asc("A")
ElseIf mOutByte(i) >= 26 And mOutByte(i) <= 51 Then
mOutByte(i) = mOutByte(i) - 26 + Asc("a")
ElseIf mOutByte(i) >= 52 And mOutByte(i) <= 61 Then
mOutByte(i) = mOutByte(i) - 52 + Asc("0")
ElseIf mOutByte(i) = 62 Then
mOutByte(i) = Asc("+")
Else
mOutByte(i) = Asc("/")
End If
Next i
If Num = 1 Then
mOutByte(2) = Asc("=")
mOutByte(3) = Asc("=")
ElseIf Num = 2 Then
mOutByte(3) = Asc("=")
End If
End Sub
Public Sub Base64DecodeByte(mInByte() As Byte, mOutByte() As Byte, ByteNum As Integer)
Dim tByte As Byte
Dim i As Integer
ByteNum = 0
For i = 0 To 3
If mInByte(i) >= Asc("A") And mInByte(i) <= Asc("Z") Then
mInByte(i) = mInByte(i) - Asc("A")
ElseIf mInByte(i) >= Asc("a") And mInByte(i) <= Asc("z") Then
mInByte(i) = mInByte(i) - Asc("a") + 26
ElseIf mInByte(i) >= Asc("0") And mInByte(i) <= Asc("9") Then
mInByte(i) = mInByte(i) - Asc("0") + 52
ElseIf mInByte(i) = Asc("+") Then
mInByte(i) = 62
ElseIf mInByte(i) = Asc("/") Then
mInByte(i) = 63
Else
ByteNum = ByteNum + 1
mInByte(i) = 0
End If
Next i
tByte = (mInByte(0) And &H3F) * 4 + (mInByte(1) And &H30) / 16
mOutByte(0) = tByte
tByte = (mInByte(1) And &HF) * 16 + (mInByte(2) And &H3C) / 4
mOutByte(1) = tByte
tByte = (mInByte(2) And &H3) * 64 + (mInByte(3) And &H3F)
mOutByte(2) = tByte
End Sub
Public Function Base64DecodeFile(Infile As String, Outfile As String)
Dim FnumIn As Integer, FnumOut As Integer
Dim mInByte(4) As Byte, mOutByte(3) As Byte
Dim myByte As Byte
Dim i As Integer, LineLen As Integer, j As Integer
Dim ByteNum As Integer
FnumIn = FreeFile()
Open Infile For Binary As #FnumIn
FnumOut = FreeFile()
Open Outfile For Binary As #FnumOut
While Not EOF(FnumIn)
i = 0
Do While i < 4
Get #FnumIn, , myByte
If Not EOF(FnumIn) Then
If myByte <> &HA And myByte <> &HD Then
mInByte(i) = myByte
i = i + 1
End If
Else
Exit Do
End If
Loop
Base64DecodeByte mInByte, mOutByte, ByteNum
For j = 0 To 2 - ByteNum
Put #FnumOut, , mOutByte(j)
Next j
Wend
Close FnumOut
Close FnumIn
End Function
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