84 lines
2.7 KiB
JavaScript
84 lines
2.7 KiB
JavaScript
(function(){
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/*\
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|*|
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|*| Base64 / binary data / UTF-8 strings utilities (#1)
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|*|
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|*| https://developer.mozilla.org/en-US/docs/Web/API/WindowBase64/Base64_encoding_and_decoding
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|*|
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|*| Author: madmurphy
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|*|
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|*| Harald Wolff-Thobaben: Small adaptions to create a static class
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|*|
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\*/
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class Base64
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{
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constructor(){
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}
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static b64ToUint6(nChr){
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return nChr > 64 && nChr < 91 ?
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nChr - 65
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: nChr > 96 && nChr < 123 ?
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nChr - 71
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: nChr > 47 && nChr < 58 ?
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nChr + 4
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: nChr === 43 ?
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62
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: nChr === 47 ?
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63
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:
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0;
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}
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static uint6ToB64(nUint6){
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return nUint6 < 26 ?
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nUint6 + 65
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: nUint6 < 52 ?
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nUint6 + 71
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: nUint6 < 62 ?
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nUint6 - 4
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: nUint6 === 62 ?
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43
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: nUint6 === 63 ?
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47
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:
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65;
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}
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static encode(aBytes){
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var eqLen = (3 - (aBytes.length % 3)) % 3, sB64Enc = "";
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for (var nMod3, nLen = aBytes.length, nUint24 = 0, nIdx = 0; nIdx < nLen; nIdx++) {
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nMod3 = nIdx % 3;
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nUint24 |= aBytes[nIdx] << (16 >>> nMod3 & 24);
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if (nMod3 === 2 || aBytes.length - nIdx === 1) {
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sB64Enc += String.fromCharCode(Base64.uint6ToB64(nUint24 >>> 18 & 63), Base64.uint6ToB64(nUint24 >>> 12 & 63), Base64.uint6ToB64(nUint24 >>> 6 & 63), Base64.uint6ToB64(nUint24 & 63));
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nUint24 = 0;
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}
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}
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return eqLen === 0 ?
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sB64Enc
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:
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sB64Enc.substring(0, sB64Enc.length - eqLen) + (eqLen === 1 ? "=" : "==");
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}
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static decode(sBase64, nBlockSize) {
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var
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sB64Enc = sBase64.replace(/[^A-Za-z0-9\+\/]/g, ""), nInLen = sB64Enc.length,
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nOutLen = nBlockSize ? Math.ceil((nInLen * 3 + 1 >>> 2) / nBlockSize) * nBlockSize : nInLen * 3 + 1 >>> 2, aBytes = new Uint8Array(nOutLen);
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for (var nMod3, nMod4, nUint24 = 0, nOutIdx = 0, nInIdx = 0; nInIdx < nInLen; nInIdx++) {
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nMod4 = nInIdx & 3;
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nUint24 |= Base64.b64ToUint6(sB64Enc.charCodeAt(nInIdx)) << 18 - 6 * nMod4;
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if (nMod4 === 3 || nInLen - nInIdx === 1) {
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for (nMod3 = 0; nMod3 < 3 && nOutIdx < nOutLen; nMod3++, nOutIdx++) {
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aBytes[nOutIdx] = nUint24 >>> (16 >>> nMod3 & 24) & 255;
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}
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nUint24 = 0;
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}
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}
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return aBytes;
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}
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}
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LN.$add("LN.Base64",Base64);
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})(); |