R524809
60 lines
1.8 KiB
TypeScript
60 lines
1.8 KiB
TypeScript
import {
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createDecipheriv,
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createCipheriv,
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createHash,
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createHmac,
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randomBytes,
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} from 'node:crypto';
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export type EncryptedStoreSecret = {
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ciphertext: Buffer;
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nonce: Buffer;
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fingerprint: string;
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};
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/**
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* 密钥只在此边界短暂以明文存在。数据库保存 AES-GCM 密文和随机 nonce，
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* fingerprint 是不可逆 HMAC，仅用于安全地识别同一份密钥。
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*/
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export function encryptStoreSecret(
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plaintext: string,
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keyMaterial: string,
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): EncryptedStoreSecret {
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const key = createHash('sha256').update(keyMaterial).digest();
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const nonce = randomBytes(12);
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const cipher = createCipheriv('aes-256-gcm', key, nonce);
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const ciphertext = Buffer.concat([
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cipher.update(plaintext, 'utf8'),
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cipher.final(),
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cipher.getAuthTag(),
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]);
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return {
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ciphertext,
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nonce,
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fingerprint: createHmac('sha256', key)
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.update(plaintext)
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.digest('base64url'),
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};
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}
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/** 仅供受信任的后台 Worker 使用；调用方不得记录返回值。 */
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export function decryptStoreSecret(
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ciphertextWithTag: Buffer,
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nonce: Buffer,
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keyMaterial: string,
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): string {
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const authenticationTagLength = 16;
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if (ciphertextWithTag.length <= authenticationTagLength) {
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throw new Error('Invalid encrypted store secret');
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}
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const key = createHash('sha256').update(keyMaterial).digest();
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const ciphertext = ciphertextWithTag.subarray(0, -authenticationTagLength);
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const tag = ciphertextWithTag.subarray(-authenticationTagLength);
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const decipher = createDecipheriv('aes-256-gcm', key, nonce);
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decipher.setAuthTag(tag);
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return Buffer.concat([
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decipher.update(ciphertext),
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decipher.final(),
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]).toString('utf8');
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}
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