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

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

backend/src/ee/routes/v1/external-kms-router.ts

@@ -4,9 +4,15 @@ import { ExternalKmsSchema, KmsKeysSchema } from "@app/db/schemas";
 import { EventType } from "@app/ee/services/audit-log/audit-log-types";
 import {
   ExternalKmsAwsSchema,
+  ExternalKmsGcpCredentialSchema,
+  ExternalKmsGcpSchema,
   ExternalKmsInputSchema,
-  ExternalKmsInputUpdateSchema
+  ExternalKmsInputUpdateSchema,
+  KmsGcpKeyFetchAuthType,
+  KmsProviders,
+  TExternalKmsGcpCredentialSchema
 } from "@app/ee/services/external-kms/providers/model";
+import { NotFoundError } from "@app/lib/errors";
 import { readLimit, writeLimit } from "@app/server/config/rateLimiter";
 import { verifyAuth } from "@app/server/plugins/auth/verify-auth";
 import { AuthMode } from "@app/services/auth/auth-type";
@@ -44,7 +50,8 @@ const sanitizedExternalSchemaForGetById = KmsKeysSchema.extend({
     statusDetails: true,
     provider: true
   }).extend({
-    providerInput: ExternalKmsAwsSchema
+    // for GCP, we don't return the credential object as it is sensitive data that should not be exposed
+    providerInput: z.union([ExternalKmsAwsSchema, ExternalKmsGcpSchema.pick({ gcpRegion: true, keyName: true })])
   })
 });
 
@@ -286,4 +293,67 @@ export const registerExternalKmsRouter = async (server: FastifyZodProvider) => {
       return { externalKms };
     }
   });
+
+  server.route({
+    method: "POST",
+    url: "/gcp/keys",
+    config: {
+      rateLimit: writeLimit
+    },
+    schema: {
+      body: z.discriminatedUnion("authMethod", [
+        z.object({
+          authMethod: z.literal(KmsGcpKeyFetchAuthType.Credential),
+          region: z.string().trim().min(1),
+          credential: ExternalKmsGcpCredentialSchema
+        }),
+        z.object({
+          authMethod: z.literal(KmsGcpKeyFetchAuthType.Kms),
+          region: z.string().trim().min(1),
+          kmsId: z.string().trim().min(1)
+        })
+      ]),
+      response: {
+        200: z.object({
+          keys: z.string().array()
+        })
+      }
+    },
+    onRequest: verifyAuth([AuthMode.JWT, AuthMode.IDENTITY_ACCESS_TOKEN]),
+    handler: async (req) => {
+      const { region, authMethod } = req.body;
+      let credentialJson: TExternalKmsGcpCredentialSchema | undefined;
+
+      if (authMethod === KmsGcpKeyFetchAuthType.Credential) {
+        credentialJson = req.body.credential;
+      } else if (authMethod === KmsGcpKeyFetchAuthType.Kms) {
+        const externalKms = await server.services.externalKms.findById({
+          actor: req.permission.type,
+          actorId: req.permission.id,
+          actorAuthMethod: req.permission.authMethod,
+          actorOrgId: req.permission.orgId,
+          id: req.body.kmsId
+        });
+
+        if (!externalKms || externalKms.external.provider !== KmsProviders.Gcp) {
+          throw new NotFoundError({ message: "KMS not found or not of type GCP" });
+        }
+
+        credentialJson = externalKms.external.providerInput.credential as TExternalKmsGcpCredentialSchema;
+      }
+
+      if (!credentialJson) {
+        throw new NotFoundError({
+          message: "Something went wrong while fetching the GCP credential, please check inputs and try again"
+        });
+      }
+
+      const results = await server.services.externalKms.fetchGcpKeys({
+        credential: credentialJson,
+        gcpRegion: region
+      });
+
+      return results;
+    }
+  });
 };