295 lines
10 KiB
JavaScript
295 lines
10 KiB
JavaScript
/**
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* base64.ts
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*
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* Licensed under the BSD 3-Clause License.
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* http://opensource.org/licenses/BSD-3-Clause
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*
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* References:
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* http://en.wikipedia.org/wiki/Base64
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*
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* @author Dan Kogai (https://github.com/dankogai)
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*/
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const version = '3.7.7';
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/**
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* @deprecated use lowercase `version`.
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*/
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const VERSION = version;
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const _hasBuffer = typeof Buffer === 'function';
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const _TD = typeof TextDecoder === 'function' ? new TextDecoder() : undefined;
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const _TE = typeof TextEncoder === 'function' ? new TextEncoder() : undefined;
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const b64ch = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
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const b64chs = Array.prototype.slice.call(b64ch);
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const b64tab = ((a) => {
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let tab = {};
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a.forEach((c, i) => tab[c] = i);
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return tab;
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})(b64chs);
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const b64re = /^(?:[A-Za-z\d+\/]{4})*?(?:[A-Za-z\d+\/]{2}(?:==)?|[A-Za-z\d+\/]{3}=?)?$/;
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const _fromCC = String.fromCharCode.bind(String);
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const _U8Afrom = typeof Uint8Array.from === 'function'
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? Uint8Array.from.bind(Uint8Array)
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: (it) => new Uint8Array(Array.prototype.slice.call(it, 0));
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const _mkUriSafe = (src) => src
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.replace(/=/g, '').replace(/[+\/]/g, (m0) => m0 == '+' ? '-' : '_');
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const _tidyB64 = (s) => s.replace(/[^A-Za-z0-9\+\/]/g, '');
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/**
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* polyfill version of `btoa`
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*/
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const btoaPolyfill = (bin) => {
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// console.log('polyfilled');
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let u32, c0, c1, c2, asc = '';
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const pad = bin.length % 3;
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for (let i = 0; i < bin.length;) {
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if ((c0 = bin.charCodeAt(i++)) > 255 ||
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(c1 = bin.charCodeAt(i++)) > 255 ||
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(c2 = bin.charCodeAt(i++)) > 255)
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throw new TypeError('invalid character found');
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u32 = (c0 << 16) | (c1 << 8) | c2;
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asc += b64chs[u32 >> 18 & 63]
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+ b64chs[u32 >> 12 & 63]
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+ b64chs[u32 >> 6 & 63]
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+ b64chs[u32 & 63];
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}
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return pad ? asc.slice(0, pad - 3) + "===".substring(pad) : asc;
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};
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/**
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* does what `window.btoa` of web browsers do.
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* @param {String} bin binary string
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* @returns {string} Base64-encoded string
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*/
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const _btoa = typeof btoa === 'function' ? (bin) => btoa(bin)
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: _hasBuffer ? (bin) => Buffer.from(bin, 'binary').toString('base64')
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: btoaPolyfill;
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const _fromUint8Array = _hasBuffer
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? (u8a) => Buffer.from(u8a).toString('base64')
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: (u8a) => {
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// cf. https://stackoverflow.com/questions/12710001/how-to-convert-uint8-array-to-base64-encoded-string/12713326#12713326
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const maxargs = 0x1000;
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let strs = [];
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for (let i = 0, l = u8a.length; i < l; i += maxargs) {
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strs.push(_fromCC.apply(null, u8a.subarray(i, i + maxargs)));
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}
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return _btoa(strs.join(''));
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};
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/**
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* converts a Uint8Array to a Base64 string.
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* @param {boolean} [urlsafe] URL-and-filename-safe a la RFC4648 §5
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* @returns {string} Base64 string
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*/
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const fromUint8Array = (u8a, urlsafe = false) => urlsafe ? _mkUriSafe(_fromUint8Array(u8a)) : _fromUint8Array(u8a);
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// This trick is found broken https://github.com/dankogai/js-base64/issues/130
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// const utob = (src: string) => unescape(encodeURIComponent(src));
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// reverting good old fationed regexp
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const cb_utob = (c) => {
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if (c.length < 2) {
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var cc = c.charCodeAt(0);
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return cc < 0x80 ? c
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: cc < 0x800 ? (_fromCC(0xc0 | (cc >>> 6))
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+ _fromCC(0x80 | (cc & 0x3f)))
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: (_fromCC(0xe0 | ((cc >>> 12) & 0x0f))
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+ _fromCC(0x80 | ((cc >>> 6) & 0x3f))
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+ _fromCC(0x80 | (cc & 0x3f)));
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}
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else {
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var cc = 0x10000
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+ (c.charCodeAt(0) - 0xD800) * 0x400
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+ (c.charCodeAt(1) - 0xDC00);
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return (_fromCC(0xf0 | ((cc >>> 18) & 0x07))
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+ _fromCC(0x80 | ((cc >>> 12) & 0x3f))
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+ _fromCC(0x80 | ((cc >>> 6) & 0x3f))
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+ _fromCC(0x80 | (cc & 0x3f)));
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}
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};
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const re_utob = /[\uD800-\uDBFF][\uDC00-\uDFFFF]|[^\x00-\x7F]/g;
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/**
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* @deprecated should have been internal use only.
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* @param {string} src UTF-8 string
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* @returns {string} UTF-16 string
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*/
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const utob = (u) => u.replace(re_utob, cb_utob);
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//
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const _encode = _hasBuffer
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? (s) => Buffer.from(s, 'utf8').toString('base64')
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: _TE
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? (s) => _fromUint8Array(_TE.encode(s))
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: (s) => _btoa(utob(s));
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/**
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* converts a UTF-8-encoded string to a Base64 string.
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* @param {boolean} [urlsafe] if `true` make the result URL-safe
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* @returns {string} Base64 string
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*/
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const encode = (src, urlsafe = false) => urlsafe
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? _mkUriSafe(_encode(src))
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: _encode(src);
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/**
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* converts a UTF-8-encoded string to URL-safe Base64 RFC4648 §5.
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* @returns {string} Base64 string
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*/
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const encodeURI = (src) => encode(src, true);
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// This trick is found broken https://github.com/dankogai/js-base64/issues/130
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// const btou = (src: string) => decodeURIComponent(escape(src));
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// reverting good old fationed regexp
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const re_btou = /[\xC0-\xDF][\x80-\xBF]|[\xE0-\xEF][\x80-\xBF]{2}|[\xF0-\xF7][\x80-\xBF]{3}/g;
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const cb_btou = (cccc) => {
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switch (cccc.length) {
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case 4:
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var cp = ((0x07 & cccc.charCodeAt(0)) << 18)
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| ((0x3f & cccc.charCodeAt(1)) << 12)
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| ((0x3f & cccc.charCodeAt(2)) << 6)
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| (0x3f & cccc.charCodeAt(3)), offset = cp - 0x10000;
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return (_fromCC((offset >>> 10) + 0xD800)
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+ _fromCC((offset & 0x3FF) + 0xDC00));
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case 3:
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return _fromCC(((0x0f & cccc.charCodeAt(0)) << 12)
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| ((0x3f & cccc.charCodeAt(1)) << 6)
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| (0x3f & cccc.charCodeAt(2)));
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default:
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return _fromCC(((0x1f & cccc.charCodeAt(0)) << 6)
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| (0x3f & cccc.charCodeAt(1)));
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}
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};
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/**
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* @deprecated should have been internal use only.
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* @param {string} src UTF-16 string
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* @returns {string} UTF-8 string
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*/
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const btou = (b) => b.replace(re_btou, cb_btou);
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/**
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* polyfill version of `atob`
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*/
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const atobPolyfill = (asc) => {
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// console.log('polyfilled');
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asc = asc.replace(/\s+/g, '');
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if (!b64re.test(asc))
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throw new TypeError('malformed base64.');
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asc += '=='.slice(2 - (asc.length & 3));
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let u24, bin = '', r1, r2;
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for (let i = 0; i < asc.length;) {
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u24 = b64tab[asc.charAt(i++)] << 18
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| b64tab[asc.charAt(i++)] << 12
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| (r1 = b64tab[asc.charAt(i++)]) << 6
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| (r2 = b64tab[asc.charAt(i++)]);
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bin += r1 === 64 ? _fromCC(u24 >> 16 & 255)
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: r2 === 64 ? _fromCC(u24 >> 16 & 255, u24 >> 8 & 255)
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: _fromCC(u24 >> 16 & 255, u24 >> 8 & 255, u24 & 255);
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}
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return bin;
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};
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/**
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* does what `window.atob` of web browsers do.
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* @param {String} asc Base64-encoded string
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* @returns {string} binary string
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*/
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const _atob = typeof atob === 'function' ? (asc) => atob(_tidyB64(asc))
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: _hasBuffer ? (asc) => Buffer.from(asc, 'base64').toString('binary')
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: atobPolyfill;
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//
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const _toUint8Array = _hasBuffer
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? (a) => _U8Afrom(Buffer.from(a, 'base64'))
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: (a) => _U8Afrom(_atob(a).split('').map(c => c.charCodeAt(0)));
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/**
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* converts a Base64 string to a Uint8Array.
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*/
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const toUint8Array = (a) => _toUint8Array(_unURI(a));
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//
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const _decode = _hasBuffer
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? (a) => Buffer.from(a, 'base64').toString('utf8')
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: _TD
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? (a) => _TD.decode(_toUint8Array(a))
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: (a) => btou(_atob(a));
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const _unURI = (a) => _tidyB64(a.replace(/[-_]/g, (m0) => m0 == '-' ? '+' : '/'));
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/**
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* converts a Base64 string to a UTF-8 string.
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* @param {String} src Base64 string. Both normal and URL-safe are supported
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* @returns {string} UTF-8 string
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*/
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const decode = (src) => _decode(_unURI(src));
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/**
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* check if a value is a valid Base64 string
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* @param {String} src a value to check
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*/
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const isValid = (src) => {
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if (typeof src !== 'string')
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return false;
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const s = src.replace(/\s+/g, '').replace(/={0,2}$/, '');
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return !/[^\s0-9a-zA-Z\+/]/.test(s) || !/[^\s0-9a-zA-Z\-_]/.test(s);
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};
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//
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const _noEnum = (v) => {
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return {
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value: v, enumerable: false, writable: true, configurable: true
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};
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};
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/**
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* extend String.prototype with relevant methods
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*/
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const extendString = function () {
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const _add = (name, body) => Object.defineProperty(String.prototype, name, _noEnum(body));
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_add('fromBase64', function () { return decode(this); });
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_add('toBase64', function (urlsafe) { return encode(this, urlsafe); });
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_add('toBase64URI', function () { return encode(this, true); });
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_add('toBase64URL', function () { return encode(this, true); });
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_add('toUint8Array', function () { return toUint8Array(this); });
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};
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/**
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* extend Uint8Array.prototype with relevant methods
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*/
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const extendUint8Array = function () {
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const _add = (name, body) => Object.defineProperty(Uint8Array.prototype, name, _noEnum(body));
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_add('toBase64', function (urlsafe) { return fromUint8Array(this, urlsafe); });
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_add('toBase64URI', function () { return fromUint8Array(this, true); });
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_add('toBase64URL', function () { return fromUint8Array(this, true); });
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};
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/**
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* extend Builtin prototypes with relevant methods
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*/
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const extendBuiltins = () => {
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extendString();
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extendUint8Array();
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};
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const gBase64 = {
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version: version,
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VERSION: VERSION,
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atob: _atob,
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atobPolyfill: atobPolyfill,
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btoa: _btoa,
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btoaPolyfill: btoaPolyfill,
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fromBase64: decode,
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toBase64: encode,
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encode: encode,
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encodeURI: encodeURI,
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encodeURL: encodeURI,
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utob: utob,
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btou: btou,
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decode: decode,
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isValid: isValid,
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fromUint8Array: fromUint8Array,
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toUint8Array: toUint8Array,
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extendString: extendString,
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extendUint8Array: extendUint8Array,
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extendBuiltins: extendBuiltins
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};
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// makecjs:CUT //
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export { version };
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export { VERSION };
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export { _atob as atob };
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export { atobPolyfill };
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export { _btoa as btoa };
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export { btoaPolyfill };
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export { decode as fromBase64 };
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export { encode as toBase64 };
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export { utob };
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export { encode };
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export { encodeURI };
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export { encodeURI as encodeURL };
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export { btou };
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export { decode };
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export { isValid };
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export { fromUint8Array };
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export { toUint8Array };
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export { extendString };
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export { extendUint8Array };
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export { extendBuiltins };
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// and finally,
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export { gBase64 as Base64 };
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