feat(GCP): Implement key generation (#12)

Fixes #8.

- [x] refactor

package.json

@@ -43,11 +43,13 @@
     "@google-cloud/kms": "^3.5.0",
     "@peculiar/webcrypto": "^1.4.2",
     "fast-crc32c": "^2.0.0",
+    "uuid4": "^2.0.3",
     "webcrypto-core": "^1.7.6"
   },
   "devDependencies": {
     "@relaycorp/shared-config": "^1.9.3",
     "@types/jest": "^28.1.6",
+    "@types/uuid4": "^2.0.0",
     "del-cli": "^5.0.0",
     "jest": "^28.1.3",
     "jest-extended": "^3.2.4",

src/lib/gcp/GcpKmsConfig.ts

@@ -0,0 +1,8 @@
+export type ProtectionLevel = 'SOFTWARE' | 'HSM';
+
+export interface GcpKmsConfig {
+  readonly location: string;
+  readonly keyRing: string;
+  readonly protectionLevel: ProtectionLevel;
+  readonly destroyScheduledDurationSeconds?: number;
+}

src/lib/gcp/GcpKmsRsaPssPrivateKey.spec.ts

@@ -4,7 +4,7 @@ import { HashingAlgorithm } from '../algorithms';
 
 const HASHING_ALGORITHM: HashingAlgorithm = 'SHA-256';
 const KMS_KEY_PATH = 'projects/foo/key/42';
-const KMS_PROVIDER = new GcpKmsRsaPssProvider(null as any);
+const KMS_PROVIDER = new GcpKmsRsaPssProvider(null as any, null as any);
 
 test('KMS key path should be honored', () => {
   const key = new GcpKmsRsaPssPrivateKey(KMS_KEY_PATH, HASHING_ALGORITHM, KMS_PROVIDER);

src/lib/gcp/GcpKmsRsaPssPrivateKey.ts

@@ -1,6 +1,6 @@
 import { GcpKmsRsaPssProvider } from './GcpKmsRsaPssProvider';
 import { RsaPssPrivateKey } from '../PrivateKey';
-import { HashingAlgorithm } from '../algorithms.js';
+import { HashingAlgorithm } from '../algorithms';
 
 export class GcpKmsRsaPssPrivateKey extends RsaPssPrivateKey {
   constructor(