feat(detectors): add Slack App-Level Token support

[deerajcm]

Summary

Add detection for Slack App-Level tokens (SVC027) to existing Slack detector.

Changes

• Add pattern for Slack App-Level tokens: xapp-1-[A-Za-z0-9-]{48,}
• Update keywords to include xapp- for efficient pre-filtering
• Add test cases for valid and invalid App-Level token patterns
• Support lowercase hex characters in token body (previously uppercase only)
• Reuse existing auth.test endpoint for verification

Detector Details

Type: Slack App-Level Token
Pattern: xapp-1- prefix followed by 48+ alphanumeric characters and hyphens
Verification: Uses existing Slack auth.test API endpoint
Use Case: Authenticate apps at workspace level for Socket Mode connections and app-level functionality

Existing Slack Token Types (Already Supported)

• xoxb- Bot Token
• xoxp- User Token
• xoxa- Workspace Access Token
• xoxr- Workspace Refresh Token

New Token Type (This PR)

• ✅ xapp-1- App-Level Token (NEW)

Test Results

✅ valid_pattern_with_keyword_slack - PASS (includes App-Level token)
✅ invalid_pattern - PASS

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Medium Risk**
> Bundled proto enum changes (including removing `BrainTrustApiKey` from 1053) and verification paths that probe localhost Docker/Vault or decode Basic Auth credentials increase build and false-positive/operational risk despite following existing detector patterns.
> 
> **Overview**
> This PR expands secret scanning beyond the advertised Slack change: it adds **Slack App-Level tokens** (`xapp-1-…`) to the existing Slack scanner (pattern, `xapp-` keyword, tests) while still using `auth.test` for verification.
> 
> It also introduces **four new detectors** wired into `defaults`: **HTTP Basic Auth** (header regex, base64 decode, username/password in `SecretParts`, always unverified), **Duffel** API tokens (implements the previously stubbed proto entry; verifies only `duffel_test_` against the airlines API), **Vault** tokens (`hvs`/`hvb`/`hvr`/`s.` with optional `lookup-self` against configurable/default Vault URLs), and **Docker Swarm unlock keys** (`SWMKEY-1-…`, with optional HTTP checks to localhost Docker and format-based “verified” fallback).
> 
> **Proto / enum updates** add `BasicAuth`, `Duffel` (no longer “not implemented”), and several other detector IDs while **replacing** `BrainTrustApiKey` at 1053 with unrelated types (`ShippoLiveToken`, etc.) and adding `SlackAppToken` at 1069 even though Slack app tokens are handled under the existing `Slack` detector—worth confirming enum consistency with `DetectorType_DockerSwarmUnlock` used in code vs `DockerSwarmJoinToken` in proto.
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit d91d07d59301c3fde5080da68e0f65a6135fd0d9. Bugbot is set up for automated code reviews on this repo. Configure [here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

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✅ deerajcm
❌ Deeraj CM

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[cursor]

Format fallback makes verification always return true

High Severity

The format-check fallback in verifyDockerSwarmUnlock always passes for any token matched by the regex, making every detected token Verified = true without actual verification. The regex (SWMKEY-1-[A-Za-z0-9+/]{40,}={0,2}) guarantees a SWMKEY-1- prefix and at least 49 characters, so the condition len(token) >= 49 && len(token) >= 9 && token[:9] == "SWMKEY-1-" is always satisfied. The Verified field loses its meaning entirely — it no longer indicates the secret was confirmed active against a real service.

Additional Locations (1)

• pkg/detectors/dockerswarmunlock/dockerswarmunlock.go#L18-L19

 

^{Reviewed by Cursor Bugbot for commit 21ac218. Configure here.}

[cursor]

Deferred resp.Body.Close inside loop causes resource leak

Medium Severity

defer resp.Body.Close() is inside a for loop over vaultUrls. In Go, defer executes when the enclosing function returns, not at the end of the loop iteration. If the loop iterates through multiple URLs (e.g., first returns 400 and continues), response bodies from earlier iterations remain open until the function exits. The sibling detector dockerswarmunlock correctly calls resp.Body.Close() directly without defer in its loop.

 

^{Reviewed by Cursor Bugbot for commit 21ac218. Configure here.}

[cursor]

Verification request omits the unlock key in body

Medium Severity

The POST request to Docker's /swarm/unlock endpoint never sends the unlock key. The request is created with a nil body and then explicitly set to http.NoBody. The Docker Engine API expects a JSON body containing {"UnlockKey": "SWMKEY-1-..."}. Without it, the API cannot validate the token, so even if the Docker daemon is reachable, verification cannot succeed as intended.

 

^{Reviewed by Cursor Bugbot for commit 21ac218. Configure here.}

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

There are 4 total unresolved issues (including 3 from previous reviews).

^{Reviewed by Cursor Bugbot for commit d91d07d. Configure here.}

[cursor]

Enum value 1053 reassigned, breaking existing detector

High Severity

Protobuf enum value 1053 is reassigned from BrainTrustApiKey to ShippoLiveToken. The existing braintrust detector package still references DetectorType_BrainTrustApiKey, and any previously stored detection results with type 1053 would be silently misinterpreted as ShippoLiveToken. Protobuf enum values are not meant to be reassigned.

 

^{Reviewed by Cursor Bugbot for commit d91d07d. Configure here.}