46 lines
1.2 KiB
JavaScript
46 lines
1.2 KiB
JavaScript
const crypto = require('crypto');
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function makeToken(secret, counter) {
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const hmac = crypto.createHmac('sha256', secret);
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hmac.update(String(counter));
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return hmac.digest('hex');
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}
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class Metadata {
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constructor(obj, storage) {
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this.id = obj.id;
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this.dl = +obj.dl || 0;
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this.dlToken = +obj.dlToken || 0;
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this.dlimit = +obj.dlimit || 1;
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this.pwd = !!+obj.pwd;
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this.owner = obj.owner;
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this.metadata = obj.metadata;
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this.auth = obj.auth;
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this.nonce = obj.nonce;
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this.flagged = !!obj.flagged;
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this.dead = !!obj.dead;
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this.fxa = !!+obj.fxa;
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this.storage = storage;
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}
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async getDownloadToken() {
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if (this.dlToken >= this.dlimit) {
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throw new Error('limit');
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}
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this.dlToken = await this.storage.incrementField(this.id, 'dlToken');
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// another request could have also incremented
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if (this.dlToken > this.dlimit) {
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throw new Error('limit');
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}
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return makeToken(this.owner, this.dlToken);
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}
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async verifyDownloadToken(token) {
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const validTokens = Array.from({ length: this.dlToken }, (_, i) =>
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makeToken(this.owner, i + 1)
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);
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return validTokens.includes(token);
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}
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}
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module.exports = Metadata;
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