30 lines
816 B
TypeScript
30 lines
816 B
TypeScript
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export function pkcs7Pad(data: Uint8Array): Uint8Array {
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const padder = 16 - (data.length % 16);
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const result = new Uint8Array(data.length + padder);
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result.set(data);
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for (let i = data.length; i < result.length; i++) {
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result[i] = padder;
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}
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return result;
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}
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export function pkcs7Strip(data: Uint8Array): Uint8Array {
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if (data.length < 16) { throw new TypeError('PKCS#7 invalid length'); }
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const padder = data[data.length - 1];
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if (padder > 16) { throw new TypeError('PKCS#7 padding byte out of range'); }
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const length = data.length - padder;
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for (let i = 0; i < padder; i++) {
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if (data[length + i] !== padder) {
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throw new TypeError('PKCS#7 invalid padding byte');
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}
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}
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return new Uint8Array(data.subarray(0, length));
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}
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