bb3f5385fc
- 10 source files: types, aes-gcm, 3 key providers (memory/env/akv), envelope, key-cache, dek-store, guards, migration, factory - 42 Vitest tests: AES-GCM roundtrips, tamper detection, unicode, 100KB payloads, key providers, DEK cache TTL/LRU, envelope lifecycle, migration (dry-run + idempotent), config validation - AKV MEK creation script (scripts/create-encryption-keys.sh) for 10 product MEKs - .env.example updated with FIELD_ENCRYPT_* vars
63 lines
2.1 KiB
TypeScript
63 lines
2.1 KiB
TypeScript
/**
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* @bytelyst/field-encrypt — Environment variable key provider
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*
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* For dev/staging — uses a hex-encoded symmetric key from an env var.
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* Matches the existing MFA pattern (AUTH_TOTP_ENCRYPTION_KEY).
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*
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* Wrapping uses AES-256-GCM with the env key as MEK.
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*/
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import { createCipheriv, createDecipheriv, randomBytes, createHash } from 'node:crypto';
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import type { KeyProvider } from './types.js';
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const ALGORITHM = 'aes-256-gcm';
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const IV_BYTES = 12;
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export class EnvKeyProvider implements KeyProvider {
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private readonly mek: Buffer;
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private readonly version: string;
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/**
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* @param keyHex - Hex-encoded 32-byte key (64 hex chars).
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* If shorter, it will be SHA-256 hashed to derive a 32-byte key.
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*/
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constructor(keyHex: string) {
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if (!keyHex || keyHex.length === 0) {
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throw new Error('EnvKeyProvider: encryption key must not be empty');
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}
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if (keyHex.length === 64) {
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this.mek = Buffer.from(keyHex, 'hex');
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} else {
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// Hash to 32 bytes — same approach as existing MFA encryption
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this.mek = createHash('sha256').update(keyHex).digest();
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}
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this.version = 'env-v1';
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}
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async wrapKey(dek: Buffer): Promise<{ wrappedKey: string; mekVersion: string }> {
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const iv = randomBytes(IV_BYTES);
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const cipher = createCipheriv(ALGORITHM, this.mek, iv);
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let encrypted = cipher.update(dek);
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encrypted = Buffer.concat([encrypted, cipher.final()]);
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const tag = cipher.getAuthTag();
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const wrapped = Buffer.concat([iv, tag, encrypted]);
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return { wrappedKey: wrapped.toString('hex'), mekVersion: this.version };
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}
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async unwrapKey(wrappedKeyHex: string, _mekVersion: string): Promise<Buffer> {
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const wrapped = Buffer.from(wrappedKeyHex, 'hex');
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const iv = wrapped.subarray(0, IV_BYTES);
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const tag = wrapped.subarray(IV_BYTES, IV_BYTES + 16);
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const ciphertext = wrapped.subarray(IV_BYTES + 16);
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const decipher = createDecipheriv(ALGORITHM, this.mek, iv);
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decipher.setAuthTag(tag);
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let decrypted = decipher.update(ciphertext);
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decrypted = Buffer.concat([decrypted, decipher.final()]);
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return decrypted;
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}
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}
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