wurenji-xcx/static/js/Base64.js

export default function Base64() {
	// 私钥
	let _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
	// 加密
	this.encode = function(input) {
		var output = "";
		var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
		var i = 0;
		input = _utf8_encode(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;
	}
	// 解密
	this.decode = (input) => {
		var output = "";
		var chr1, chr2, chr3;
		var enc1, enc2, enc3, enc4;
		var i = 0;
		if (input == undefined || input == null) {

		} else {
			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 = output + String.fromCharCode(chr1);
				if (enc3 != 64) {
					output = output + String.fromCharCode(chr2);
				}
				if (enc4 != 64) {
					output = output + String.fromCharCode(chr3);
				}
			}
			output = _utf8_decode(output);
			return output;
		}

	}
	// private method for UTF-8 encoding
	let _utf8_encode = (string) => {
		string = string.replace(/\r\n/g, "\n");
		var utftext = "";
		for (var n = 0; n < string.length; n++) {
			var 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;
	}
	// private method for UTF-8 decoding
	let _utf8_decode = (utftext) => {
		var string = "";
		var i = 0;
		var c = c1 = c2 = 0;
		var c1 = 0;
		var c2 = 0;
		var 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;
	}
}