| 1 | import { Buffer } from "node:buffer";
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| 2 | import { createHmac, timingSafeEqual } from "node:crypto";
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| 3 |
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| 4 | function s2b(str: string, encoding: BufferEncoding): Buffer {
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| 5 | return Buffer.from(str, encoding);
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| 6 | }
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| 7 |
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| 8 | function safeCompare(a: Buffer, b: Buffer): boolean {
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| 9 | if (a.length !== b.length) {
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| 10 | return false;
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| 11 | }
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| 12 | return timingSafeEqual(a, b);
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| 13 | }
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| 14 |
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| 15 | export default function validateSignature(
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| 16 | body: string | Buffer,
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| 17 | channelSecret: string,
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| 18 | signature: string,
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| 19 | ): boolean {
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| 20 | return safeCompare(
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| 21 | createHmac("SHA256", channelSecret).update(body).digest(),
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| 22 | s2b(signature, "base64"),
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| 23 | );
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| 24 | }
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