fix(external-kms): use sanitized AWS provider schema in read responses

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

@@ -3,10 +3,10 @@ import { z } from "zod";
 import { ExternalKmsSchema, KmsKeysSchema } from "@app/db/schemas";
 import { EventType } from "@app/ee/services/audit-log/audit-log-types";
 import {
-  ExternalKmsAwsSchema,
   ExternalKmsGcpSchema,
   ExternalKmsInputSchema,
-  ExternalKmsInputUpdateSchema
+  ExternalKmsInputUpdateSchema,
+  SanitizedExternalKmsAwsSchema
 } from "@app/ee/services/external-kms/providers/model";
 import { readLimit, writeLimit } from "@app/server/config/rateLimiter";
 import { verifyAuth } from "@app/server/plugins/auth/verify-auth";
@@ -45,8 +45,11 @@ const sanitizedExternalSchemaForGetById = KmsKeysSchema.extend({
     statusDetails: true,
     provider: true
   }).extend({
-    // 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 })])
+    // neither provider returns sensitive credential material in read responses: AWS via the sanitized schema (access key only, no secret key), GCP via the picked fields only
+    providerInput: z.union([
+      SanitizedExternalKmsAwsSchema,
+      ExternalKmsGcpSchema.pick({ gcpRegion: true, keyName: true })
+    ])
   })
 });
 

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

@@ -0,0 +1,51 @@
+import { describe, expect, test } from "vitest";
+
+import { ExternalKmsAwsSchema, KmsAwsCredentialType, SanitizedExternalKmsAwsSchema } from "./model";
+
+describe("SanitizedExternalKmsAwsSchema (external-KMS read response)", () => {
+  const awsAccessKeyInput = {
+    credential: {
+      type: KmsAwsCredentialType.AccessKey,
+      data: {
+        accessKey: "AKIAEXAMPLE",
+        secretKey: "super-secret-value"
+      }
+    },
+    awsRegion: "us-east-1",
+    kmsKeyId: "key-123"
+  };
+
+  test("strips secretKey from an access-key credential on read", () => {
+    const parsed = SanitizedExternalKmsAwsSchema.parse(awsAccessKeyInput);
+
+    expect(parsed.credential.type).toBe(KmsAwsCredentialType.AccessKey);
+    expect(parsed.credential.data).toHaveProperty("accessKey", "AKIAEXAMPLE");
+    expect(parsed.credential.data).not.toHaveProperty("secretKey");
+    // the secret value must not survive serialization anywhere in the response
+    expect(JSON.stringify(parsed)).not.toContain("super-secret-value");
+  });
+
+  test("negative control: the pre-fix unsanitized schema would have returned secretKey", () => {
+    const parsed = ExternalKmsAwsSchema.parse(awsAccessKeyInput);
+
+    expect(parsed.credential.data).toHaveProperty("secretKey", "super-secret-value");
+  });
+
+  test("retains assume-role identifiers (that branch carries no secret material)", () => {
+    const parsed = SanitizedExternalKmsAwsSchema.parse({
+      credential: {
+        type: KmsAwsCredentialType.AssumeRole,
+        data: {
+          assumeRoleArn: "arn:aws:iam::123456789012:role/infisical",
+          externalId: "ext-1"
+        }
+      },
+      awsRegion: "us-east-1"
+    });
+
+    expect(parsed.credential.data).toMatchObject({
+      assumeRoleArn: "arn:aws:iam::123456789012:role/infisical",
+      externalId: "ext-1"
+    });
+  });
+});