目录
核心代码
function Base64() {
const keyStr = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
const utf8Encode = function(str) {
let string = str;
string = string.replace(/\r\n/g, '\n');
let utfText = '';
for (let n = 0; n < string.length; n++) {
const c = string.charCodeAt(n);
if (c < 128) {
utfText += String.fromCharCode(c);
} else if ((c > 127) && (c < 2048)) {
utfText += String.fromCharCode((c >> 6) | 192);
utfText += String.fromCharCode((c & 63) | 128);
} else {
utfText += String.fromCharCode((c >> 12) | 224);
utfText += String.fromCharCode(((c >> 6) & 63) | 128);
utfText += String.fromCharCode((c & 63) | 128);
}
}
return utfText;
};
const utf8Decode = function(utfText) {
let string = '';
let i = 0;
let c = 0;
let c2 = 0;
let c3 = 0;
while (i < utfText.length) {
c = utfText.charCodeAt(i);
if (c < 128) {
string += String.fromCharCode(c);
i++;
} else if ((c > 191) && (c < 224)) {
c2 = utfText.charCodeAt(i + 1);
string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
i += 2;
} else {
c2 = utfText.charCodeAt(i + 1);
c3 = utfText.charCodeAt(i + 2);
string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
i += 3;
}
}
return string;
};
this.encode = function(str) {
let input = str;
let output = '';
let chr1;
let chr2;
let chr3;
let enc1;
let enc2;
let enc3;
let enc4;
let i = 0;
input = utf8Encode(input);
while (i < input.length) {
chr1 = input.charCodeAt(i++);
chr2 = input.charCodeAt(i++);
chr3 = input.charCodeAt(i++);
enc1 = chr1 >> 2;
enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
enc4 = chr3 & 63;
if (isNaN(chr2)) {
enc3 = enc4 = 64;
} else if (isNaN(chr3)) {
enc4 = 64;
}
output = output +
keyStr.charAt(enc1) + keyStr.charAt(enc2) +
keyStr.charAt(enc3) + keyStr.charAt(enc4);
}
return output;
};
this.decode = function(str) {
let input = str;
let output = '';
let chr1;
let chr2;
let chr3;
let enc1;
let enc2;
let enc3;
let enc4;
let i = 0;
input = input.replace(/[^A-Za-z0-9\+\/\=]/g, '');
while (i < input.length) {
enc1 = keyStr.indexOf(input.charAt(i++));
enc2 = keyStr.indexOf(input.charAt(i++));
enc3 = keyStr.indexOf(input.charAt(i++));
enc4 = keyStr.indexOf(input.charAt(i++));
chr1 = (enc1 << 2) | (enc2 >> 4);
chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
chr3 = ((enc3 & 3) << 6) | enc4;
output += String.fromCharCode(chr1);
if (enc3 !== 64) {
output += String.fromCharCode(chr2);
}
if (enc4 !== 64) {
output += String.fromCharCode(chr3);
}
}
output = utf8Decode(output);
return output;
};
}
完整代码演示
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title></title>
<link rel="stylesheet" href="">
</head>
<style>
.Int {
width: 100%;
height: 50px;
margin-bottom: 30px;
}
.box {
width: 600px;
height: 300px;
border: 1px solid pink;
margin: 30px auto;
}
</style>
<body>
<input id="Int" class="Int" />
<button onclick="handleEncode()">点击查看Base64加密</button onclick="">
<button onclick="handleDecode()">点击查看Base64解密</button>
<div id="box" class="box"></div>
</body>
<script>
function Base64() {
const keyStr = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
const utf8Encode = function(str) {
let string = str;
string = string.replace(/\r\n/g, '\n');
let utfText = '';
for (let n = 0; n < string.length; n++) {
const c = string.charCodeAt(n);
if (c < 128) {
utfText += String.fromCharCode(c);
} else if ((c > 127) && (c < 2048)) {
utfText += String.fromCharCode((c >> 6) | 192);
utfText += String.fromCharCode((c & 63) | 128);
} else {
utfText += String.fromCharCode((c >> 12) | 224);
utfText += String.fromCharCode(((c >> 6) & 63) | 128);
utfText += String.fromCharCode((c & 63) | 128);
}
}
return utfText;
};
const utf8Decode = function(utfText) {
let string = '';
let i = 0;
let c = 0;
let c2 = 0;
let c3 = 0;
while (i < utfText.length) {
c = utfText.charCodeAt(i);
if (c < 128) {
string += String.fromCharCode(c);
i++;
} else if ((c > 191) && (c < 224)) {
c2 = utfText.charCodeAt(i + 1);
string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
i += 2;
} else {
c2 = utfText.charCodeAt(i + 1);
c3 = utfText.charCodeAt(i + 2);
string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
i += 3;
}
}
return string;
};
this.encode = function(str) {
let input = str;
let output = '';
let chr1;
let chr2;
let chr3;
let enc1;
let enc2;
let enc3;
let enc4;
let i = 0;
input = utf8Encode(input);
while (i < input.length) {
chr1 = input.charCodeAt(i++);
chr2 = input.charCodeAt(i++);
chr3 = input.charCodeAt(i++);
enc1 = chr1 >> 2;
enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
enc4 = chr3 & 63;
if (isNaN(chr2)) {
enc3 = enc4 = 64;
} else if (isNaN(chr3)) {
enc4 = 64;
}
output = output +
keyStr.charAt(enc1) + keyStr.charAt(enc2) +
keyStr.charAt(enc3) + keyStr.charAt(enc4);
}
return output;
};
this.decode = function(str) {
let input = str;
let output = '';
let chr1;
let chr2;
let chr3;
let enc1;
let enc2;
let enc3;
let enc4;
let i = 0;
input = input.replace(/[^A-Za-z0-9\+\/\=]/g, '');
while (i < input.length) {
enc1 = keyStr.indexOf(input.charAt(i++));
enc2 = keyStr.indexOf(input.charAt(i++));
enc3 = keyStr.indexOf(input.charAt(i++));
enc4 = keyStr.indexOf(input.charAt(i++));
chr1 = (enc1 << 2) | (enc2 >> 4);
chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
chr3 = ((enc3 & 3) << 6) | enc4;
output += String.fromCharCode(chr1);
if (enc3 !== 64) {
output += String.fromCharCode(chr2);
}
if (enc4 !== 64) {
output += String.fromCharCode(chr3);
}
}
output = utf8Decode(output);
return output;
};
}
const base64 = new Base64()
const input = document.getElementById("Int")
const box = document.getElementById("box")
function handleEncode() {
const val = input.value
console.log(val, 'val加密')
const result = base64.encode(val)
console.log(result, 'result加密')
box.innerHTML = result
}
function handleDecode() {
const val = input.value
console.log(val, 'val解密')
const result = base64.decode(val)
console.log(result, 'result解密')
box.innerHTML = result
}
</script>
</html>