asp如何还原用Base64加密过的二进制文件。

[wxflywing]

我在程序中接收到一段用Base64加密过的二进制文件，怎么还原？
主要是用什么类型的变量存放解密的内容，还有就是怎么转换十进制到二进制

[xzyan80]

up

[qunluo]

base64编码、解码函数

这是我看完几个base64编码、解码函数后自己改写的。
因为，在中文操作系统的VBscript中，使用的是unicode字符集，所以
很多base64编码、解码函数在理论上是正确的，但实际不能运行！

我加写了几个Unicode与Ansi编码转换的函数，现贴出来，请大家执教！


文件名称base64test.asp

<%

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

[qunluo]

'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


'---------------------------------------------------------------------------------
response.write strUnicode2Ansi("abc我们d我们") & "<hr>"
response.write strAnsi2Unicode(Base64encode(strUnicode2Ansi("abc我们d我们"))) & "<hr>"
response.write strAnsi2Unicode(Base64encode(strUnicode2Ansi("abc我们d我们a"))) & "<hr>"
response.write strAnsi2Unicode(Base64encode(strUnicode2Ansi("abc我们d我们ab"))) & "<hr>"
response.write strAnsi2Unicode(Base64encode(strUnicode2Ansi("abc我们d我们abc"))) & "<hr>"

response.write strAnsi2Unicode(Base64decode(Base64encode(strUnicode2Ansi("abc我们d我们")))) & "<hr>"
response.write strAnsi2Unicode(Base64decode(Base64encode(strUnicode2Ansi("abc我们d我们a")))) & "<hr>"
response.write strAnsi2Unicode(Base64decode(Base64encode(strUnicode2Ansi("abc我们d我们ab")))) & "<hr>"
response.write strAnsi2Unicode(Base64decode(Base64encode(strUnicode2Ansi("abc我们d我们abc")))) & "<hr>"


sdecode="Sm1haWy1xNb30qqyzsr9wdCx7Q0K1/fV36O6dG9ueTEzMiAgMjAwMC0wNS0yNNXixqq45bz+sbvU"
sdecode=sdecode & "xLbBPT0xNTK0zg0KIA0KDQqhoaGh1/fV3yBb0ru/y10gDQqhoaGhIA0KoaGhoQ0KoaGhocu1w/ej"
sdecode=sdecode & "urj8tuC1xNDFz6LH67LOv7xKbWFpbMu1w/ejrM7Sz+vV4tLRvq3X47m708O1xMHLoaMNCqGhoaEN"
sdecode=sdecode & "CqGhoaHT9rW9zsrM4sfrsrvSqs7KztKjrNLyzqq3/s7xxvfUrdLyo6zO0r32vfbKudPDQ0RPTlRT"
sdecode=sdecode & "t6LQxaOsU29ycnkuLi4NCqGhoaENCqGhoaGjqDGjqUJvZHmjqNDFvP7V/c7Eo6kgOiDX1rf7tK4N"
sdecode=sdecode & "CqGhoaENCqGhoaHI56O6Sk1haWwuQm9keSA9ICLV4sDvv8nS1MrH08O7p8zu0LS1xLHttaXE2sjd"
sdecode=sdecode & "o6y/ydLUyKHX1EZyb22hoyINCqGhoaENCqGhoaENCqGhoaGjqDKjqUNoYXJzZXSjqNfWt/u8r6Os"
sdecode=sdecode & "yLHKoc6qIlVTLUFTQ0lJIqOpIDog19a3+7SuDQqhoaGhDQqhoaGhyOejukpNYWlsLkNoYXJzZXQg"
sdecode=sdecode & "PSAiVVMtQVNDSUkiIA0KoaGhoQ0KoaGhoaOoM6OpQ29udGVudFRyYW5zZmVyRW5jb2RpbmcgOiDX"
sdecode=sdecode & "1rf7tK4NCqGhoaENCqGhoaHWuLaoxNrI3bSry83KsbXEseDC67e9yr2jrMixyqHKxyJRdW90ZWQt"
sdecode=sdecode & "UHJpbnRhYmxlIiANCqGhoaHI56O6Sk1haWwuQ29udGVudFRyYW5zZmVyRW5jb2RpbmcgPSAiYmFz"
sdecode=sdecode & "ZTY0Ig0KoaGhoQ0KoaGhoaOoNKOpQ29udGVudFR5cGWjqNDFvP61xGNvbnRlbnR5cGUuIMixyqHK"
sdecode=sdecode & "xyJ0ZXh0L3BsYWluIqOpIDog19a3+7SuDQqhoaGhDQqhoaGhyOe5+8Tj0tRIVE1MuPHKvbeiy83T"
sdecode=sdecode & "yrz+LCC4xM6qInRleHQvaHRtbCK8tL/JoaMgDQqhoaGhyOejukpNYWlsLkNvbnRlbnRUeXBlID0g"
sdecode=sdecode & "InRleHQvaHRtbCINCqGhoaENCqGhoaENCqGhoaGjqDWjqUVuY29kaW5nIDog19a3+7SuDQqhoaGh"
sdecode=sdecode & "DQqhoaGhyejWw7i9vP6x4MLrt73KvaOoyLHKocrHImJhc2U2NKOpoaMgv8nS1NGh1PHKudPDtcTK"
sdecode=sdecode & "xyJiYXNlNjQiLCAidXVlbmNvZGUiIG9yICJxdW90ZWQtcHJpbnRhYmxlIiANCqGhoaHI56O6Sk1h"
sdecode=sdecode & "aWwuRW5jb2RpbmcgPSAiYmFzZTY0Ig0KoaGhoQ0KoaGhoQ0KoaGhoaOoNqOpTG9no6hKbWFpbLS0"
sdecode=sdecode & "vai1xMjV1r6jrMewzOFsb2dpbmfK9NDUyejWw86qdHJ1ZaOsvPvPwsPmo6kgOiDX1rf7tK4NCqGh"
sdecode=sdecode & "oaENCqGhoaHI56O6yrnTw1Jlc3BvbnNlLldyaXRlKCBKTWFpbC5Mb2cgKdPvvuTB0LP2yNXWvtDF"
sdecode=sdecode & "z6Khow0KoaGhoQ0KoaGhoQ0KoaGhoaOoN6OpTG9nZ2luZ6Ooyse38cq508PI1da+o6kgOiCyvLb7"
sdecode=sdecode & "0M0NCqGhoaENCqGhoaHI56O6Sk1haWwuTG9nZ2luZyA9IHRydWUNCqGhoaENCqGhoaENCqGhoaGj"
sdecode=sdecode & "qDijqVJlY2lwaWVudHMgOiDX1rf7tK4NCqGhoaENCqGhoaHWu7bByvTQ1KOst7W72Mv509DK1bz+"
sdecode=sdecode & "yMsNCqGhoaHI56O6UmVzcG9uc2UuV3JpdGUoICIiICsgSk1haWwuUmVjaXBpZW50cyArICIiICk7"
sdecode=sdecode & "DQqhoaGhDQqhoaGhDQqhoaGho6g5o6lSZXBseVRvo6jWuLaosfC1xLvY0MW12Na3o6kgOiDX1rf7"
sdecode=sdecode & "tK4NCqGhoaENCqGhoaHI56O6Sk1haWwuUmVwbHlUbyA9ICJhbnlvdGhlckBtYWlsaG9zdC5jb20i"
sdecode=sdecode & "DQqhoaGhDQqhoaGhDQqhoaGho6gxMKOpU2VuZGVyo6ggt6K8/sjLtcTTyrz+tdjWt6OpIDog19a3"
sdecode=sdecode & "+7SuDQqhoaGhDQqhoaGhyOejukpNYWlsLlNlbmRlciA9ICJzZW5kZXJAbWFpbGhvc3QuY29tIg0K"
sdecode=sdecode & "oaGhoQ0KoaGhoQ0KoaGhoaOoMTGjqVNlbmRlck5hbWWjqLeivP7Iy7XE0NXD+6OpIDog19a3+7Su"
sdecode=sdecode & "DQqhoaGhDQqhoaGhyOejukpNYWlsLlNlbmRlck5hbWUgPSAi0ru/yyINCqGhoaENCqGhoaENCqGh"
sdecode=sdecode & "oaGjqDEyo6lTZXJ2ZXJBZGRyZXNzo6jTyrz+t/7O8cb3tcS12Na3o6kgOiDX1rf7tK4NCqGhoaEN"

response.write replace(strAnsi2Unicode(Base64decode(strUnicode2Ansi(sdecode))),chr(13)&chr(10),"<br>") & "<hr>"

response.end


%>

[qunluo]

不好意思，看错了！！呵！！！！



再看看再说！！！

[wxflywing]

晕，谢谢楼上的好意，这么长，你辛苦了。
base64加密解密不是问题，最主要的是怎么处理成二进制数据流

adodb.stream 可以吗？

[xjdawu]

好,就用adodb.stream,服务器端用Request.BinaryRead,用Jscript来做服务器端脚本
-----------------------------------
<script language=jscript runat=server>
... ...
var code = Request.BinaryRead("code");
code = code.toString(10);//转10进制
... ...
</script>

[wxflywing]

楼上的大侠，看不太懂啊。

那里用到了adodb.stream?

var code = Request.BinaryRead("code");
//得到二进制数据流？我得到的是Base64加密过的数据啊，例如“P8I/PQAAAAAAAAAAPgM...”

[xjdawu]

用adodb.stream是你自己提出来的，加密解密你也说没问题，所以我只是表示赞同，再贴一句进制转换的代码