Base64_encode encryption and decryption in javascript

Urlencode rawurlencode and other common functions are used to process parameters in the process of passing parameters in a program. However, in actual operations, the author finds that these functions always encounter problems in processing, the most common urlencode parameter pairs in a series of webpage jumps & this symbol is always handled. After the experiment, the author found that base64_encode encryption is still used and parameters are passed.

It is easy to encrypt the string using base64_encode in php, and there is a corresponding base64_decode function for decryption, but there is no response Processing Method in js, the following is a method for implementing base64_encode base64_decode in php in js.

function base64encode(str){    var out,i,len,base64EncodeChars="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";    var c1,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);    }    return out;}function base64decode(str){    var c1,c2,c3,c4,base64DecodeChars=new Array(-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);    var i,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) return out;            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) return out;            c4=base64DecodeChars[c4];        }while(i<len&&c4==-1);        if(c4==-1) break;        out+=String.fromCharCode(((c3&0x03)<<6)|c4);    }    return out;}function utf16to8(str){    var out,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);        } else if(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));        }    }    return out;}function utf8to16(str){    var out,i,len,c;    var char2,char3;    out="";    len=str.length;    i=0;    while(i<len){        c=str.charCodeAt(i++);        switch (c>>4){        case 0:        case 1:        case 2:        case 3:        case 4:        case 5:        case 6:        case 7:            // 0xxxxxxx            out+=str.charAt(i-1);            break;        case 12:        case 13:            // 110x xxxx   10xx xxxx            char2=str.charCodeAt(i++);            out+=String.fromCharCode(((c&0x1F)<<6)|(char2&0x3F));            break;        case 14:            // 1110 xxxx  10xx xxxx  10xx xxxx            char2=str.charCodeAt(i++);            char3=str.charCodeAt(i++);            out+=String.fromCharCode(((c&0x0F)<<12)|((char2&0x3F)<<6)|((char3&0x3F)<<0));            break;        }    }    return out;}

The Code has been excerpted from the Internet, but some improvements have been made. Some code circulating on the Internet declares two relatively large global variables, which have some impact on performance.

Implement base64_encode encryption in javascript, and compress and download decrypted Functions

Code example reference: base64 encryption, decryption

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