22 lines
672 B
JavaScript
22 lines
672 B
JavaScript
// https://www.w3.org/TR/PNG/#5PNG-file-signature
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const pngSignature = Uint8Array.of(137, 80, 78, 71, 13, 10, 26, 10);
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export function writeSignature(buffer) {
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buffer.writeBytes(pngSignature);
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}
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export function checkSignature(buffer) {
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if (!hasPngSignature(buffer.readBytes(pngSignature.length))) {
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throw new Error('wrong PNG signature');
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}
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}
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export function hasPngSignature(array) {
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if (array.length < pngSignature.length) {
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return false;
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}
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for (let i = 0; i < pngSignature.length; i++) {
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if (array[i] !== pngSignature[i]) {
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return false;
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}
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}
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return true;
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}
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//# sourceMappingURL=signature.js.map
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