feat(KMS): New external KMS support for Google GCP KMS (#2825)

* feat(KMS): New external KMS support for Google GCP KMS

backend/src/ee/services/external-kms/providers/gcp-kms.ts

@@ -0,0 +1,113 @@
+import { KeyManagementServiceClient } from "@google-cloud/kms";
+
+import { BadRequestError } from "@app/lib/errors";
+import { logger } from "@app/lib/logger";
+
+import { ExternalKmsGcpSchema, TExternalKmsGcpClientSchema, TExternalKmsProviderFns } from "./model";
+
+const getGcpKmsClient = async ({ credential, gcpRegion }: TExternalKmsGcpClientSchema) => {
+  const gcpKmsClient = new KeyManagementServiceClient({
+    credentials: credential
+  });
+  const projectId = credential.project_id;
+  const locationName = gcpKmsClient.locationPath(projectId, gcpRegion);
+
+  return {
+    gcpKmsClient,
+    locationName
+  };
+};
+
+type GcpKmsProviderArgs = {
+  inputs: unknown;
+};
+type TGcpKmsProviderFactoryReturn = TExternalKmsProviderFns & {
+  getKeysList: () => Promise<{ keys: string[] }>;
+};
+
+export const GcpKmsProviderFactory = async ({ inputs }: GcpKmsProviderArgs): Promise<TGcpKmsProviderFactoryReturn> => {
+  const { credential, gcpRegion, keyName } = await ExternalKmsGcpSchema.parseAsync(inputs);
+  const { gcpKmsClient, locationName } = await getGcpKmsClient({
+    credential,
+    gcpRegion
+  });
+
+  const validateConnection = async () => {
+    try {
+      await gcpKmsClient.listKeyRings({
+        parent: locationName
+      });
+      return true;
+    } catch (error) {
+      throw new BadRequestError({
+        message: "Cannot connect to GCP KMS"
+      });
+    }
+  };
+
+  // Used when adding the KMS to fetch the list of keys in specified region
+  const getKeysList = async () => {
+    try {
+      const [keyRings] = await gcpKmsClient.listKeyRings({
+        parent: locationName
+      });
+
+      const validKeyRings = keyRings
+        .filter(
+          (keyRing): keyRing is { name: string } =>
+            keyRing !== null && typeof keyRing === "object" && "name" in keyRing && typeof keyRing.name === "string"
+        )
+        .map((keyRing) => keyRing.name);
+      const keyList: string[] = [];
+      const keyListPromises = validKeyRings.map((keyRingName) =>
+        gcpKmsClient
+          .listCryptoKeys({
+            parent: keyRingName
+          })
+          .then(([cryptoKeys]) =>
+            cryptoKeys
+              .filter(
+                (key): key is { name: string } =>
+                  key !== null && typeof key === "object" && "name" in key && typeof key.name === "string"
+              )
+              .map((key) => key.name)
+          )
+      );
+
+      const cryptoKeyLists = await Promise.all(keyListPromises);
+      keyList.push(...cryptoKeyLists.flat());
+      return { keys: keyList };
+    } catch (error) {
+      logger.error(error, "Could not validate GCP KMS connection and credentials");
+      throw new BadRequestError({
+        message: "Could not validate GCP KMS connection and credentials",
+        error
+      });
+    }
+  };
+
+  const encrypt = async (data: Buffer) => {
+    const encryptedText = await gcpKmsClient.encrypt({
+      name: keyName,
+      plaintext: data
+    });
+    if (!encryptedText[0].ciphertext) throw new Error("encryption failed");
+    return { encryptedBlob: Buffer.from(encryptedText[0].ciphertext) };
+  };
+
+  const decrypt = async (encryptedBlob: Buffer) => {
+    const decryptedText = await gcpKmsClient.decrypt({
+      name: keyName,
+      ciphertext: encryptedBlob
+    });
+    if (!decryptedText[0].plaintext) throw new Error("decryption failed");
+    return { data: Buffer.from(decryptedText[0].plaintext) };
+  };
+
+  return {
+    validateConnection,
+    getKeysList,
+    encrypt,
+    decrypt
+  };
+};

backend/src/ee/services/external-kms/providers/model.ts

@@ -1,13 +1,23 @@
 import { z } from "zod";
 
 export enum KmsProviders {
-  Aws = "aws"
+  Aws = "aws",
+  Gcp = "gcp"
 }
 
 export enum KmsAwsCredentialType {
   AssumeRole = "assume-role",
   AccessKey = "access-key"
 }
+// Google uses snake_case for their enum values and we need to match that
+export enum KmsGcpCredentialType {
+  ServiceAccount = "service_account"
+}
+
+export enum KmsGcpKeyFetchAuthType {
+  Credential = "credential",
+  Kms = "kmsId"
+}
 
 export const ExternalKmsAwsSchema = z.object({
   credential: z
@@ -42,14 +52,44 @@ export const ExternalKmsAwsSchema = z.object({
 });
 export type TExternalKmsAwsSchema = z.infer<typeof ExternalKmsAwsSchema>;
 
+export const ExternalKmsGcpCredentialSchema = z.object({
+  type: z.literal(KmsGcpCredentialType.ServiceAccount),
+  project_id: z.string().min(1),
+  private_key_id: z.string().min(1),
+  private_key: z.string().min(1),
+  client_email: z.string().min(1),
+  client_id: z.string().min(1),
+  auth_uri: z.string().min(1),
+  token_uri: z.string().min(1),
+  auth_provider_x509_cert_url: z.string().min(1),
+  client_x509_cert_url: z.string().min(1),
+  universe_domain: z.string().min(1)
+});
+
+export type TExternalKmsGcpCredentialSchema = z.infer<typeof ExternalKmsGcpCredentialSchema>;
+
+export const ExternalKmsGcpSchema = z.object({
+  credential: ExternalKmsGcpCredentialSchema.describe("GCP Service Account JSON credential to connect"),
+  gcpRegion: z.string().trim().describe("GCP region where the KMS key is located"),
+  keyName: z.string().trim().describe("GCP key name")
+});
+export type TExternalKmsGcpSchema = z.infer<typeof ExternalKmsGcpSchema>;
+
+const ExternalKmsGcpClientSchema = ExternalKmsGcpSchema.pick({ gcpRegion: true }).extend({
+  credential: ExternalKmsGcpCredentialSchema
+});
+export type TExternalKmsGcpClientSchema = z.infer<typeof ExternalKmsGcpClientSchema>;
+
 // The root schema of the JSON
 export const ExternalKmsInputSchema = z.discriminatedUnion("type", [
-  z.object({ type: z.literal(KmsProviders.Aws), inputs: ExternalKmsAwsSchema })
+  z.object({ type: z.literal(KmsProviders.Aws), inputs: ExternalKmsAwsSchema }),
+  z.object({ type: z.literal(KmsProviders.Gcp), inputs: ExternalKmsGcpSchema })
 ]);
 export type TExternalKmsInputSchema = z.infer<typeof ExternalKmsInputSchema>;
 
 export const ExternalKmsInputUpdateSchema = z.discriminatedUnion("type", [
-  z.object({ type: z.literal(KmsProviders.Aws), inputs: ExternalKmsAwsSchema.partial() })
+  z.object({ type: z.literal(KmsProviders.Aws), inputs: ExternalKmsAwsSchema.partial() }),
+  z.object({ type: z.literal(KmsProviders.Gcp), inputs: ExternalKmsGcpSchema.partial() })
 ]);
 export type TExternalKmsInputUpdateSchema = z.infer<typeof ExternalKmsInputUpdateSchema>;