ASP常用加密解密算法-Base64-OK
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ASP常用加密解密算法-Base64
[code] <% sBASE_64_CHARACTERS = "Iz01BScostuDEKxT9WvM23LQh+/NeFGHklijUV678mnw4JApqrXOPdYZaRfgbCy5" '64個不重復的字符 sBASE_64_CHARACTERS = strUnicode2Ansi(sBASE_64_CHARACTERS) Function strUnicodeLen(asContents) '計算unicode字符串的Ansi編碼的長度 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) '將Unicode編碼的字符串,轉換成Ansi編碼的字符串 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) '將Ansi編碼的字符串,轉換成Unicode編碼的字符串 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) '將Ansi編碼的字符串進行Base64編碼 'asContents應當是ANSI編碼的字符串(二進制的字符串也可以) 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)) '補足位數是為了便于計算 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 '處理最后剩余的幾個字符 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=號補足位數 else lsGroup64 = Char1 & Char2 & Char3 & ChrB(61) '用=號補足位數 end if lsResult = lsResult & lsGroup64 end if Base64encode = lsResult End Function Function Base64decode(asContents) '將Base64編碼字符串轉換成Ansi編碼的字符串 'asContents應當也是ANSI編碼的字符串(二進制的字符串也可以) 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 '字符串長度應當是4的倍數 Base64decode = "" exit Function end if '判斷最后一位是不是 = 號 '判斷倒數第二位是不是 = 號 '這里m4表示最后剩余的需要單獨處理的字符個數 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 '處理最后剩余的幾個字符 if M4 > 0 then lsGroupBinary = "" lsGroup64 = Midb(asContents, len2+1, m4) & chrB(65) 'chr(65)=A,轉換成值為0 if M4=2 then '補足4位,是為了便于計算 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 If Request.ServerVariables("REQUEST_METHOD") = "POST" Then plaintext=request.form("plaintext") response.write " 輸入的明文是: "&replace(plaintext,chr(13)," ") cryptext=Base64encode(plaintext) response.write " 加密的密文是: " &cryptext decryptext=Base64decode(cryptext) response.write " 解密的明文是: " &replace(decryptext,chr(13)," ") end if %> [/code] 該文章在 2010/5/8 16:07:43 編輯過 |
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