求ASP加密和解密函数

[xilo]

要求:
1,无论多长的字符串加密后的长度是一样的,就像md5那样.
2,可以解密

因为对这方面不了解,不知道能不能实现这个...

[一把编程的菜刀]

使用Asp的base64编码、解码函数

[一把编程的菜刀]

<%

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

%>

[一把编程的菜刀]

使用Asp的base64编码、解码函数
你在GOOGLE搜索下ASP base64

[xilo]

那些都不符合,我要的是:无论多长的字符串加密后的长度是一样的,就像md5那样

[wcwtitxu]

[Quote=引用 4 楼 xilo 的回复:]
我要的是:无论多长的字符串加密后的长度是一样的,就像md5那样
[/Quote]
还要能解密
你要能写出来, Rar 就得淘汰了

[xilo]

顶上去，希望得到解决

[一把编程的菜刀]

[Quote=引用 4 楼 xilo 的回复:]
那些都不符合,我要的是:无论多长的字符串加密后的长度是一样的,就像md5那样
[/Quote]

呵呵，你花1000RMB未必有人给你写这样一个，就算人家有这么一个，也不一定会卖给你，更可况免费的

[天宇余]

能解密的就加密不成长度一样的

[kencorn]

mark

[md5e]

希望你能找到,good luck!

[bcexe]

编程动力 http://www.bcexe.com 专业的编程开发类网站,网络编程,软件开发,网站开发,

一切尽在这里!

[锐昆]

对加密解密不了解,

不过我也在找这样的函数. 真的没有么?

[wcwtitxu]

这是不可能的好不好!

要有的话,岂不是可以把 无限个硬盘 里所有内容BASE64后, 加密成定长的字符串, 想用时还能解密回来.

空间无限了..

[yangtututu]

来个 乾坤大挪移