JS实现的base64加密解密完整实例
本文实例讲述了JS实现的base64加密解密。分享给大家供大家参考，具体如下：
完整的代码：
<HTML>
<HEAD>
<TITLE>Base64</TITLE>
<scriptlanguage=javascript>
varbase64EncodeChars="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
varbase64DecodeChars=newArray(
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,62,-1,-1,-1,63,
52,53,54,55,56,57,58,59,60,61,-1,-1,-1,-1,-1,-1,
-1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,
15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1,
-1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,
41,42,43,44,45,46,47,48,49,50,51,-1,-1,-1,-1,-1);
<HTML>
<HEAD>
<TITLE>Base64</TITLE>
<scriptlanguage=JavaScript>
varbase64EncodeChars="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
varbase64DecodeChars=newArray(
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,62,-1,-1,-1,63,
52,53,54,55,56,57,58,59,60,61,-1,-1,-1,-1,-1,-1,
-1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,
15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1,
-1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,
41,42,43,44,45,46,47,48,49,50,51,-1,-1,-1,-1,-1);
functionbase64encode(str){
varout,i,len;
varc1,c2,c3;
len=str.length;
i=0;
out="";
while(i<len){
c1=str.charCodeAt(i++)&0xff;
if(i==len)
{
out+=base64EncodeChars.charAt(c1>>2);
out+=base64EncodeChars.charAt((c1&0x3)<<4);
out+="==";
break;
}
c2=str.charCodeAt(i++);
if(i==len)
{
out+=base64EncodeChars.charAt(c1>>2);
out+=base64EncodeChars.charAt(((c1&0x3)<<4)|((c2&0xF0)>>4));
out+=base64EncodeChars.charAt((c2&0xF)<<2);
out+="=";
break;
}
c3=str.charCodeAt(i++);
out+=base64EncodeChars.charAt(c1>>2);
out+=base64EncodeChars.charAt(((c1&0x3)<<4)|((c2&0xF0)>>4));
out+=base64EncodeChars.charAt(((c2&0xF)<<2)|((c3&0xC0)>>6));
out+=base64EncodeChars.charAt(c3&0x3F);
}
returnout;
}
functionbase64decode(str){
varc1,c2,c3,c4;
vari,len,out;
len=str.length;
i=0;
out="";
while(i<len){
/*c1*/
do{
c1=base64DecodeChars[str.charCodeAt(i++)&0xff];
}while(i<len&&c1==-1);
if(c1==-1)
break;
/*c2*/
do{
c2=base64DecodeChars[str.charCodeAt(i++)&0xff];
}while(i<len&&c2==-1);
if(c2==-1)
break;
out+=String.fromCharCode((c1<<2)|((c2&0x30)>>4));
/*c3*/
do{
c3=str.charCodeAt(i++)&0xff;
if(c3==61)
returnout;
c3=base64DecodeChars[c3];
}while(i<len&&c3==-1);
if(c3==-1)
break;
out+=String.fromCharCode(((c2&0XF)<<4)|((c3&0x3C)>>2));
/*c4*/
do{
c4=str.charCodeAt(i++)&0xff;
if(c4==61)
returnout;
c4=base64DecodeChars[c4];
}while(i<len&&c4==-1);
if(c4==-1)
break;
out+=String.fromCharCode(((c3&0x03)<<6)|c4);
}
returnout;
}
functionutf16to8(str){
varout,i,len,c;
out="";
len=str.length;
for(i=0;i<len;i++){
c=str.charCodeAt(i);
if((c>=0x0001)&&(c<=0x007F)){
out+=str.charAt(i);
}elseif(c>0x07FF){
out+=String.fromCharCode(0xE0|((c>>12)&0x0F));
out+=String.fromCharCode(0x80|((c>>6)&0x3F));
out+=String.fromCharCode(0x80|((c>>0)&0x3F));
}else{
out+=String.fromCharCode(0xC0|((c>>6)&0x1F));
out+=String.fromCharCode(0x80|((c>>0)&0x3F));
}
}
returnout;
}
functionutf8to16(str){
varout,i,len,c;
varchar2,char3;
out="";
len=str.length;
i=0;
while(i<len){
c=str.charCodeAt(i++);
switch(c>>4)
{
case0:case1:case2:case3:case4:case5:case6:case7:
//0xxxxxxx
out+=str.charAt(i-1);
break;
case12:case13:
//110xxxxx10xxxxxx
char2=str.charCodeAt(i++);
out+=String.fromCharCode(((c&0x1F)<<6)|(char2&0x3F));
break;
case14:
//1110xxxx10xxxxxx10xxxxxx
char2=str.charCodeAt(i++);
char3=str.charCodeAt(i++);
out+=String.fromCharCode(((c&0x0F)<<12)|
((char2&0x3F)<<6)|
((char3&0x3F)<<0));
break;
}
}
returnout;
}
functiondoit(){
varf=document.f
f.output.value=base64encode(utf16to8(f.source.value))
f.decode.value=utf8to16(base64decode(f.output.value))
}
</script>
</HEAD>
<BODY>
<H1>Base64</H1>
<FORMNAME="f">
原码<BR>
<TEXTAREANAME="source"ROWS=4COLS=60WRAP="soft"></TEXTAREA><BR><BR>
Base64encode<BR>
<TEXTAREANAME="output"ROWS=4COLS=60WRAP="soft"></TEXTAREA><BR><BR>
Base64decode<BR>
<TEXTAREANAME="decode"ROWS=4COLS=60WRAP="soft"></TEXTAREA><BR><BR>
<INPUTTYPE=BUTTONVALUE="转换"ONCLICK="doit()">
</FORM>
</BODY>
关于base64加密解密还可参看本站在线工具：
BASE64编码解码工具
更多加密解密内容还可参考：
MD5在线加密工具
URL网址16进制加密工具
迅雷、快车、旋风URL加密/解密工具
在线SHA1加密工具
更多关于JavaScript相关内容可查看本站专题：《JavaScript加密解密技巧汇总》、《JavaScript切换特效与技巧总结》、《JavaScript查找算法技巧总结》、《JavaScript动画特效与技巧汇总》、《JavaScript错误与调试技巧总结》、《JavaScript数据结构与算法技巧总结》、《JavaScript遍历算法与技巧总结》及《JavaScript数学运算用法总结》
希望本文所述对大家JavaScript程序设计有所帮助。