sheetjs/modules/04_base64.ts

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var Base64_map = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
function Base64_encode(input: string): string {
var o = "";
var c1=0, c2=0, c3=0, e1=0, e2=0, e3=0, e4=0;
for(var i = 0; i < input.length; ) {
c1 = input.charCodeAt(i++);
e1 = (c1 >> 2);
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c2 = input.charCodeAt(i++);
e2 = ((c1 & 3) << 4) | (c2 >> 4);
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c3 = input.charCodeAt(i++);
e3 = ((c2 & 15) << 2) | (c3 >> 6);
e4 = (c3 & 63);
if (isNaN(c2)) { e3 = e4 = 64; }
else if (isNaN(c3)) { e4 = 64; }
o += Base64_map.charAt(e1) + Base64_map.charAt(e2) + Base64_map.charAt(e3) + Base64_map.charAt(e4);
}
return o;
}
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function Base64_encode_pass(input: string): string {
var o = "";
var c1=0, c2=0, c3=0, e1=0, e2=0, e3=0, e4=0;
for(var i = 0; i < input.length; ) {
c1 = input.charCodeAt(i++); if(c1 > 0xFF) c1 = 0x5F;
e1 = (c1 >> 2);
c2 = input.charCodeAt(i++); if(c2 > 0xFF) c2 = 0x5F;
e2 = ((c1 & 3) << 4) | (c2 >> 4);
c3 = input.charCodeAt(i++); if(c3 > 0xFF) c3 = 0x5F;
e3 = ((c2 & 15) << 2) | (c3 >> 6);
e4 = (c3 & 63);
if (isNaN(c2)) { e3 = e4 = 64; }
else if (isNaN(c3)) { e4 = 64; }
o += Base64_map.charAt(e1) + Base64_map.charAt(e2) + Base64_map.charAt(e3) + Base64_map.charAt(e4);
}
return o;
}
function Base64_decode(input: string): string {
var o = "";
var c1=0, c2=0, c3=0, e1=0, e2=0, e3=0, e4=0;
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input = input.replace(/^data:([^\/]+\/[^\/]+)?;base64\,/,'')
.replace(/[^\w\+\/\=]/g, "")
for(var i = 0; i < input.length;) {
e1 = Base64_map.indexOf(input.charAt(i++));
e2 = Base64_map.indexOf(input.charAt(i++));
c1 = (e1 << 2) | (e2 >> 4);
o += String.fromCharCode(c1);
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e3 = Base64_map.indexOf(input.charAt(i++));
c2 = ((e2 & 15) << 4) | (e3 >> 2);
if (e3 !== 64) { o += String.fromCharCode(c2); }
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e4 = Base64_map.indexOf(input.charAt(i++));
c3 = ((e3 & 3) << 6) | e4;
if (e4 !== 64) { o += String.fromCharCode(c3); }
}
return o;
}