93 lines
2.5 KiB
JavaScript
93 lines
2.5 KiB
JavaScript
function base64_encode(str) {
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var c1, c2, c3;
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var base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
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var i = 0, len = str.length, string = '';
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while (i < len) {
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c1 = str.charCodeAt(i++) & 0xff;
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if (i == len) {
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string += base64EncodeChars.charAt(c1 >> 2);
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string += base64EncodeChars.charAt((c1 & 0x3) << 4);
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string += "==";
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break;
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}
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c2 = str.charCodeAt(i++);
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if (i == len) {
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string += base64EncodeChars.charAt(c1 >> 2);
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string += base64EncodeChars.charAt(((c1 & 0x3) << 4)
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| ((c2 & 0xF0) >> 4));
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string += base64EncodeChars.charAt((c2 & 0xF) << 2);
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string += "=";
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break;
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}
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c3 = str.charCodeAt(i++);
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string += base64EncodeChars.charAt(c1 >> 2);
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string += base64EncodeChars.charAt(((c1 & 0x3) << 4)
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| ((c2 & 0xF0) >> 4));
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string += base64EncodeChars.charAt(((c2 & 0xF) << 2)
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| ((c3 & 0xC0) >> 6));
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string += base64EncodeChars.charAt(c3 & 0x3F)
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}
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return string
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}
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function base64_decode(str) {
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var c1, c2, c3, c4;
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var base64DecodeChars = new Array(-1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62,
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-1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1,
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-1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
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15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1,
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26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42,
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43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1);
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var i = 0, len = str.length, string = '';
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while (i < len) {
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do {
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c1 = base64DecodeChars[str.charCodeAt(i++) & 0xff]
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} while (i < len && c1 == -1);
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if (c1 == -1)
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break;
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do {
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c2 = base64DecodeChars[str.charCodeAt(i++) & 0xff]
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} while (i < len && c2 == -1);
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if (c2 == -1)
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break;
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string += String.fromCharCode((c1 << 2) | ((c2 & 0x30) >> 4));
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do {
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c3 = str.charCodeAt(i++) & 0xff;
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if (c3 == 61)
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return string;
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c3 = base64DecodeChars[c3]
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} while (i < len && c3 == -1);
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if (c3 == -1)
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break;
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string += String.fromCharCode(((c2 & 0XF) << 4) | ((c3 & 0x3C) >> 2));
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do {
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c4 = str.charCodeAt(i++) & 0xff;
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if (c4 == 61)
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return string;
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c4 = base64DecodeChars[c4]
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} while (i < len && c4 == -1);
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if (c4 == -1)
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break;
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string += String.fromCharCode(((c3 & 0x03) << 6) | c4)
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}
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return string;
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}
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module.exports = {
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'base64_encode': base64_encode,
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'base64_decode': base64_decode
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}; |