BASE64解密问题，在线等

不是吧
5Lit5Zu9的再编码是
NUxpdDVadTk=

这个和汉字编码有关，JS是unicode编码，汉字的编码不同，所以加密之后的结果也不同，base64加密不是很复杂，中午的时候我测试下

<HTML><HEAD><TITLE>Test Base 64</TITLE>
<META content="MSHTML 6.00.2800.1578" name=GENERATOR></HEAD>
<BODY><TEXTAREA id=original style="WIDTH: 100%" rows=10>博客园</TEXTAREA><BUTTON onclick=Run()>encode</BUTTON> <TEXTAREA id=encode style="WIDTH: 100%" rows=10></TEXTAREA>
<SCRIPT language=javascript>
function Run()
{
    var originalString = original.value;
    encode.value = EncodeBase64(originalString);
}
var Base64Alphabet = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q',
    'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
    'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'];

var Base64Alphabet2 =
{
     'A' : 0, 'B' : 1, 'C' : 2, 'D' : 3, 'E' : 4, 'F' : 5, 'G' : 6, 'H' : 7, 'I' : 8, 'J' : 9, 'K' : 10, 'L' : 11,
     'M' : 12, 'N' : 13, 'O' : 14, 'P' : 15, 'Q' : 16, 'R' : 17, 'S' : 18, 'T' : 19, 'U' : 20, 'V' : 21,
     'W' : 22, 'X' : 23, 'Y' : 24, 'Z' : 25, 'a' : 26, 'b' : 27, 'c' : 28, 'd' : 29, 'e' : 30, 'f' : 31,
     'g' : 32, 'h' : 33, 'i' : 34, 'j' : 35, 'k' : 36, 'l' : 37, 'm' : 38, 'n' : 39, 'o' : 40, 'p' : 41,
     'q' : 42, 'r' : 43, 's' : 44, 't' : 45, 'u' : 46, 'v' : 47, 'w' : 48, 'x' : 49, 'y' : 50, 'z' : 51,
     '0' : 52, '1' : 53, '2' : 54, '3' : 55, '4' : 56, '5' : 57, '6' : 58, '7' : 59, '8' : 60, '9' : 61,

     getCharCode : function(char)
     {
          if ( char == '+' )
          {
               return 62;
          }
          else if ( char == '/' )
          {
               return 63;
          }
          else if ( char == '=' )
          {
               return 0;
          }
          else
          {
               return this[char];
          }
     }
};
function EncodeBase64(string)
{
    var hexString = string.getGBCode();
    window.status = hexString;
    var base64 = '';
    var B64A = Base64Alphabet;
    var padCount = hexString.length%3;
    var count = parseInt(hexString.length/6);
    var i = 0;
    for ( i=0 ; i < count ; ++i )
    {
         var intA = parseInt(hexString.charAt(i*6+0)+hexString.charAt(i*6+1), 16);
         var intB = parseInt(hexString.charAt(i*6+2)+hexString.charAt(i*6+3), 16);
         var intC = parseInt(hexString.charAt(i*6+4)+hexString.charAt(i*6+5), 16);
         var part1 = intA >> 2;
         var part2 = ((intA & 0x03) << 4) | (intB >> 4);
         var part3 = ((intB & 0x0f) << 2) | (intC >> 6);
         var part4 = intC & 0x3f;
         base64 += B64A[part1] + B64A[part2] + B64A[part3] + B64A[part4];
    }
    if ( padCount == 1 )
    {
         var intA = parseInt(hexString.charAt(i*6+0)+hexString.charAt(i*6+1), 16);
         var intB = parseInt(hexString.charAt(i*6+2)+hexString.charAt(i*6+3), 16);
         var part1 = intA >> 2;
         var part2 = ((intA & 0x03) << 4) | (intB >> 4);
         var part3 = ((intB & 0x0f) << 2);
         base64 += B64A[part1] + B64A[part2] + B64A[part3] + '=';
    }
    if ( padCount == 2 )
    {
         var intA = parseInt(hexString.charAt(i*6+0)+hexString.charAt(i*6+1), 16);
         var part1 = intA >> 2;
         var part2 = ((intA & 0x03) << 4);
         base64 += B64A[part1] + B64A[part2] + '==';
    }
    return base64;
}
</SCRIPT><SCRIPT language=vbscript>
function vbGetGBCode(str)
    dim i, length, s
    length = len(str)
    for i=1 to length
        hexCode = hex(asc(str.charAt(i-1)))
        if (len(hexCode) mod 2) = 0 then
            s = s & hexCode
        else
            s = s & "0" & hexCode
        end if
    next
    vbGetGBCode = s
end function
</SCRIPT><SCRIPT language=javascript>
String.prototype.getGBCode = function()
{
    return vbGetGBCode(this);
}
</SCRIPT>
<BUTTON onclick=Run2()>decode</BUTTON> <TEXTAREA id=decode style="WIDTH: 100%" rows=10></TEXTAREA>
<SCRIPT language=javascript>
function Run2()
{
     decode.value = DecodeBase64(encode.value);
}
</SCRIPT><SCRIPT language=javascript>
var Base64Alphabet2 =
{
     'A' : 0, 'B' : 1, 'C' : 2, 'D' : 3, 'E' : 4, 'F' : 5, 'G' : 6, 'H' : 7, 'I' : 8, 'J' : 9, 'K' : 10, 'L' : 11,
     'M' : 12, 'N' : 13, 'O' : 14, 'P' : 15, 'Q' : 16, 'R' : 17, 'S' : 18, 'T' : 19, 'U' : 20, 'V' : 21,
     'W' : 22, 'X' : 23, 'Y' : 24, 'Z' : 25, 'a' : 26, 'b' : 27, 'c' : 28, 'd' : 29, 'e' : 30, 'f' : 31,
     'g' : 32, 'h' : 33, 'i' : 34, 'j' : 35, 'k' : 36, 'l' : 37, 'm' : 38, 'n' : 39, 'o' : 40, 'p' : 41,
     'q' : 42, 'r' : 43, 's' : 44, 't' : 45, 'u' : 46, 'v' : 47, 'w' : 48, 'x' : 49, 'y' : 50, 'z' : 51,
     '0' : 52, '1' : 53, '2' : 54, '3' : 55, '4' : 56, '5' : 57, '6' : 58, '7' : 59, '8' : 60, '9' : 61,

     getCharCode : function(char)
     {
          if ( char == '+' )
          {
               return 62;
          }
          else if ( char == '/' )
          {
               return 63;
          }
          else if ( char == '=' )
          {
               return 0;
          }
          else
          {
               return this[char];
          }
     }
};
function DecodeBase64(strCoding)
{
    strCoding = strCoding.replace(/\s+/g, '');
    var padCount = 0;
    if ( strCoding.charAt(strCoding.length-2) == '=' )
    {
         padCount = 2;
    }
    else if ( strCoding.charAt(strCoding.length-1) == '=' )
    {
         padCount = 1;
    }
    var count = strCoding.length/4;
    var hexString = '';
    var B64A2 = Base64Alphabet2;
    for ( var i=0 ; i < count ; ++i )
    {
         var part1 = B64A2.getCharCode(strCoding.charAt(i*4));
         var part2 = B64A2.getCharCode(strCoding.charAt(i*4+1));
         var part3 = B64A2.getCharCode(strCoding.charAt(i*4+2));
         var part4 = B64A2.getCharCode(strCoding.charAt(i*4+3));
         var intA = (part1 << 2) | (part2 >> 4);
         var intB = ((part2 & 0x0f ) << 4) | (part3 >> 2);
         var intC = ((part3 & 0x03 ) << 6) | part4;
         if ( intA < 0x10 )
         {
             hexString += '0';
         }
         hexString += intA.toString(16);
         if ( intB < 0x10 )
         {
             hexString += '0';
         }
         hexString += intB.toString(16);
         if ( intC < 0x10 )
         {
              hexString += '0';
         }
         hexString += intC.toString(16);
    }
    if ( padCount > 0 )
    {
         hexString = hexString.substr(0, hexString.length-padCount*2);
    }
    return hexString.getString();
}
function jsParseInt(numString, radix)
{
    return parseInt(numString, radix);
}

String.prototype.getString = function()
{
    return vbGetString(this);
}
</SCRIPT><SCRIPT language=vbscript>
function vbGetString(hexString)
    dim i, length, s
    length = Len(hexString)/2
    for i=1 to length
        charCode = jsParseInt(Mid(hexString, i*2-1, 2), 16)
        if charCode < &H7F then
            s = s & Chr(charCode)
        else
            s = s & Chr(jsParseInt(Mid(hexString, i*2-1, 4), 16))
            i = i+1
        end if
    next
    vbGetString = s
end function
</SCRIPT>
</BODY></HTML>

测试了下，就是我说的问题，JS的内置编码是unicode码
举个例子，"中"这个字
转成可变长度字节的unicode码为E4B8AD
转成2进制为
1110 0100 1011 1000 1010 1101
然后经过base64加密后的编码为
0011 1001 0000 1011 0010 0010 0010 1101
转成索引4个字节为
57,11,34,44
经过索引去找base64的串的值5Lit

调试易

BASE64解密问题，在线等

解决方案 »