44 lines
1.4 KiB
TypeScript
44 lines
1.4 KiB
TypeScript
const base64DecodeMap = [ // starts at 0x2B
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62, 0, 0, 0, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,
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0, 0, 0, 0, 0, 0, 0, // 0x3A-0x40
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0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
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19, 20, 21, 22, 23, 24, 25, 0, 0, 0, 0, 0, 0, // 0x5B-0x0x60
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26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43,
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44, 45, 46, 47, 48, 49, 50, 51
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];
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const base64DecodeMapOffset = 0x2B;
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const base64EOF = 0x3D;
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export function decodeRestrictedBase64ToBytes(encoded: string) {
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let ch: any;
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let code: any;
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let code2: any;
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const len = encoded.length;
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const padding = encoded.charAt(len - 2) === "=" ? 2 : encoded.charAt(len - 1) === "=" ? 1 : 0;
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const decoded = new Uint8Array((encoded.length >> 2) * 3 - padding);
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for (let i = 0, j = 0; i < encoded.length;) {
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ch = encoded.charCodeAt(i++);
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code = base64DecodeMap[ch - base64DecodeMapOffset];
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ch = encoded.charCodeAt(i++);
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code2 = base64DecodeMap[ch - base64DecodeMapOffset];
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decoded[j++] = (code << 2) | ((code2 & 0x30) >> 4);
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ch = encoded.charCodeAt(i++);
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if (ch === base64EOF) {
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return decoded;
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}
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code = base64DecodeMap[ch - base64DecodeMapOffset];
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decoded[j++] = ((code2 & 0x0f) << 4) | ((code & 0x3c) >> 2);
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ch = encoded.charCodeAt(i++);
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if (ch === base64EOF) {
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return decoded;
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}
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code2 = base64DecodeMap[ch - base64DecodeMapOffset];
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decoded[j++] = ((code & 0x03) << 6) | code2;
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}
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return decoded;
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} |